History.

1999–2004: CryEngine and "Far Cry".

Crytek was founded by the German-Turkish brothers Cevat, Avni and Faruk Yerli in September 1999 in Coburg, Germany. One of their first projects was a tech demo of a game called "X-Isle: Dinosaur Island", which showcased their game engine technology that allowed for large viewing distances that other game engines could not do, at that time. They met with NVIDIA during the 1999 Electronic Entertainment Expo (E3) where their tech demo caught the attention of NVIDIA and various media groups. Crytek later signed on with NVIDIA to distribute "X-Isle" as benchmarking software for NVIDIA cards.  Crytek's first major game project was "Engalus", a first-person shooter with a cyberpunk theme and role-playing elements, which was first privately shown at E3 2000. The project first attracted publicity for the company at the 2000 ECTS with their tech demo at the NVIDIA booth, but was subsequently cancelled. Crytek was approached by Ubisoft to develop "X-Isle" into a full AAA game. This evolved into "Far Cry", which was released in March 2004. Alongside this, Crytek announced their licensable game engine, CryEngine, that was used for "X-Isle" and "Far Cry".  In February 2004, German police carried out a morning raid on Crytek offices, acting on an ex-intern's claim that Crytek was using software illegally. The police investigated for more software copies than licences purchased, but no charges were pressed. That same month, Crytek and Electronic Arts (EA) announced a strategic partnership to develop a new gaming franchise based on the CryEngine, which would eventually be the "Crysis" series. Crytek opted in this direction to showcase that the CryEngine was not limited to just what "Far Cry" had shown. Due to this partnership, Ubisoft acquired the full rights to the "Far Cry" franchise by 2006 as well as a perpetual licence to the first CryEngine, which they have since adapted into their own Dunia Engine. In December 2004, Crytek and ATI created a special cinematic machinima to demonstrate the future of PC gaming.

2004–2014: Company expansion, CryEngine 2 and 3, and later games.

In January 2006, Crytek announced the development of "Crysis", promising that it would be an original first-person shooter with a new kind of gameplay challenge requiring "adaptive tactics". The game later won several Best PC Game awards from E3 and Games Convention. In April 2006, Crytek moved to new offices in Frankfurt. The first public demonstration of Crytek's CryEngine 2 was in January 2007, one year after "Crysis" was announced. It has been licensed by many companies such as Avatar Reality, WeMade Entertainment, Entropia Universe, XLGames, Reloaded Studios.  On 11 May 2006, Crytek announced that their satellite studio in Kiev, Ukraine, had been upgraded to a full development studio, giving the company its second development studio. About a week after the upgrade of the Kiev studio, Crytek announced a new studio in Budapest, Hungary.  "Crysis" was released in November 2007. In September 2008, an expansion to "Crysis" entitled "Crysis Warhead" was released as a PC-exclusive game. In October 2011, "Crysis" was released on some consoles, allowing play of the original game via Xbox Live and the PlayStation Network.  On 14 July 2008, Crytek bought Black Sea Studios and renamed it to Crytek Black Sea. On 17 November 2008, Crytek opened an office in South Korea named Crytek, Ltd. On 3 February 2009, Crytek purchased Free Radical Design, a British video game company known for the "TimeSplitters" series, and renamed the company to Crytek UK.  In March 2009, Crytek announced on the company's website that it would introduce CryEngine 3 at the 2009 Game Developers Conference. This new engine was developed for use on PlayStation 3, Xbox 360 and PCs. In October 2009, CryEngine 3 became available in trade flow for game developers. In March 2010, CryEngine 3 was made compatible with stereoscopic 3D technology. Crytek released "Crysis 2", a direct sequel to the original game, in March 2011.  At E3 2011, Crytek exhibited several new projects, including the action game "". In September 2011, THQ and Crytek announced a partnership to develop "Homefront 2". After THQ filed for bankruptcy, Crytek acquired the "Homefront" franchise from THQ entirely in January 2013. In February 2012, Crytek announced a new cloud based social gaming network called Gface. The service is designed to help users meet people and play multiplayer video games with friends. Crytek began researching a cloud gaming system in 2005 for "Crysis", but paused development in 2007.  In April 2012, Crytek released the CryEngine 3.4 SDK which brought full DirectX 11 support to the CryEngine SDK. Crytek released "Crysis 3" in February 2013 and "Ryse: Son of Rome" in November 2013 as an Xbox One launch title. The PC version of "Ryse" was released in October 2014.  On 17 January 2013, Crytek officially opened an office in Istanbul. On 28 January 2013, Crytek opened a new studio in Austin, Texas, Crytek USA, consisting primarily of former Vigil Games employees.

Since 2014: Restructuring, new leadership, CryEngine 4 and V, and latest games.

In June 2014, reports surfaced that Crytek had missed wage payments and withheld bonuses for Crytek UK and Crytek USA employees, and the company responded that it was in a "transitional phase" as it secured capital for future projects, with a particular emphasis on online gaming. In July 2014, Crytek announced a strategic deal where the rights to "Homefront" including "" and the Crytek UK staff were transferred to Koch Media. The team continued its work on the game as the new Deep Silver Dambuster Studios. Crytek USA was restructured to remain an engine support team while development of "" was transferred to Crytek.  On 20 December 2016, Crytek announced that their studios in Hungary, Bulgaria, South Korea and China would be shut down. On 7 March 2017, Crytek sold Crytek Black Sea to Sega and The Creative Assembly. On 28 February 2018, Crytek announced that Cevat Yerli was stepping down as chief executive officer (CEO) of Crytek, with his brothers, Avni and Faruk Yerli, taking over the company's leadership as joint CEOs. Cevat continues to support the company as an advisor and major shareholder. The development of CryEngine 4 was followed by CryEngine V.  Crytek released "" (utilizing the fifth generation of the CryEngine) in 2019 -20. The company has also worked on two virtual reality projects, namely "The Climb" for the Oculus Rift and "" for the PlayStation VR, Oculus Rift and SteamVR. "Arena of Fate" was cancelled after Crytek's restructuring which saw the game's developer Crytek Black Sea sold.

Crytek GmbH is a German video game developer and software developer based in Frankfurt. Founded by the Yerli brothers in Coburg in September 1999 and moved to Frankfurt in 2006, Crytek also operates further studios in Kiev and Istanbul. Its former studios included Crytek Black Sea in Sofia, Crytek UK in Nottingham, and Crytek USA in Austin, Texas. The company is best known for developing the first instalment of the "Far Cry" series (subsequent sequels and spin-offs being developed by Ubisoft Montreal) and the "Crysis" series, the open world nature of their games which showcase the company's CryEngine, and for pushing the limits on PC specifications to achieve advanced graphics and gameplay.

Crytek是一个电子游戏开发商,由Yerli兄弟于1999年建立。Crytek总部位于德国法兰克福,目前有一家位于乌克兰基辅的分部。著名作品为游戏《极地战嚎》及《孤岛危机系列》和其游戏引擎CryENGINE。


勃兰登堡的玛利亚·伊丽欧诺拉

Engagement.

In 1616, the 22-year-old Gustavus Adolphus of Sweden started looking for a Protestant bride. He had since 1613 tried to get his mother's permission to marry the noblewoman Ebba Brahe, but this was not allowed, and he had to give up his wishes to marry her, though he continued to be in love with her. He received reports with the most flattering descriptions of the physical and mental qualities of the beautiful 17-year-old princess Maria Eleonora. Elector John Sigismund was favorably inclined towards the Swedish king, but he had become very infirm after an apoplectic stroke in the autumn of 1617. His determined Prussian wife showed a strong dislike for this Swedish suitor, because Prussia was a Polish fief and the Polish King Sigismund III Vasa still resented his loss of Sweden to Gustavus Adolphus' father Charles IX.  Maria Eleonora had additional suitors in the young William of Orange, Wladislaw Vasa of Poland, Adolf Friedrich of Mecklenburg and even the future Charles I of England. Maria Eleonora's brother George William was flattered by the offer of the British Crown Prince and proposed their younger sister Catherine (1602–1644) as a more suitable wife for the Swedish king. Maria Eleonora, however, seems to have had a preference for Gustavus Adolphus. For him it was a matter of honour to acquire the hand of Maria Eleonora and none other. He had the rooms of his castle in Stockholm redecorated and started making preparations to leave for Berlin to press his suit in person, when a letter arrived from Maria Eleonora's mother to his mother. The Electress demanded in no uncertain terms that the Queen Dowager should prevent her son's journey, as "being prejudicial to Brandenburg's interests in view of the state of war existing between Sweden and Poland". Her husband, she wrote, was "so enfeebled in will by illness that he could be persuaded to agree to anything, even if it tended to the destruction of the country". It was a rebuff that verged on an insult.

Marriage and children.

The Elector John Sigismund, Maria Eleonora's father, died on 23 December 1619, and the prospect of a Swedish marriage seemed gone with him. In the spring of 1620, however, stubborn Gustavus Adolphus arrived in Berlin. The Electress Dowager maintained an attitude of reserve and even refused to grant the Swedish king a personal meeting with Maria Eleonora. All those who were present, however, noticed the princess's interest in the young king. Afterwards, Gustavus Adolphus made a round of other Protestant German courts with the professed intention of inspecting a few matrimonial alternatives. On his return to Berlin, the Electress Dowager seems to have become completely captivated by the charming Swedish king. After plighting his troth to Maria Eleonora, Gustavus Adolphus hurried back to Sweden to make arrangements for the reception of his bride.  The new Elector, George William, who resided in Prussia, was appalled when he heard of his mother's independent action. He wrote to Gustavus Adolphus to refuse his consent to the marriage until Sweden and Poland had settled their differences. It was the Electress Dowager, however, who, in accordance with Hohenzollern family custom, had the last word in bestowing her daughter's hand in marriage. She sent Maria Eleonora to territory outside of George William's reach and concluded the marriage negotiations herself.  Anna of Prussia provided herself with a selection of objects of value from the exchequer before she joined Maria Eleonora in Brunswick. A detachment of the Swedish fleet took the women over to Kalmar, where Gustavus Adolphus was impatiently awaiting them. The wedding took place in Stockholm on 25 November 1620. A comedy was performed based on the history of Olof Skötkonung. Gustavus Adolphus - in his own words - finally "had a Brandenburg lady in his marriage bed". Anna of Prussia actually stayed with her daughter in Sweden for several years after the marriage.  Gustavus Adolphus shared Maria Eleonora's interest in architecture and her love of music, while she was sentimentally devoted to her husband. Often, she lamented that she never had her hero for herself. Foreign ambassadors found her gracious and beautiful and she had good taste, although her character showed some extravagant traits. Maria Eleonora had a definite liking for entertainment and sweetmeats, and she soon succumbed to the current fashionable craze for buffoons and dwarfs. She spoke French, the court language of the age, but never bothered to learn to write German or Swedish correctly.  Within six months of their marriage, Gustavus Adolphus left to command the siege of Riga, leaving Maria Eleonora in the early stages of her first pregnancy. She lived exclusively in the company of her German ladies-in-waiting and had difficulty in adapting herself to the Swedish people, countryside and climate. She disliked the bad roads, sombre forests and wooded houses, roofed with turf. She also pined for her husband. A year after their wedding she had a miscarriage and became seriously ill. She was tempestuous, excessive, neurotic and jealous. She was often given to harsh language, and she did not spare her husband, even when strangers were present. Her emotional life lacked balance, and everything Maria Eleonora undertook on her own initiative needed careful watching. Soon Gustavus Adolphus' intimates knew that his married life was a source of grief and anxiety.  In the autumn of 1623 Maria Eleonora gave birth to a daughter, but the baby died the next year. At that time, the only surviving male heirs were the hated king of Poland and his sons. With Gustavus Adolphus risking his life in battles, an heir to the throne was anxiously awaited. In the autumn Maria Eleonora was pregnant for a third time. In May 1625 she was in good spirits and insisted on accompanying her husband on the royal yacht to review the fleet. There seemed to be no danger, as the warships were moored just opposite the castle, but a sudden storm nearly capsized the yacht. The queen was hurried back to the castle, but when she got there she was heard to exclaim: "Jesus, I cannot feel my child!" Shortly afterwards the longed-for son was stillborn.

Birth of Christina.

With the renewal of the war with Poland, Gustavus Adolphus had to leave his wife again. It is likely that she gave way to depression and grief, as we know she did in 1627, and it is probably for this reason that the king let his queen join him in Livonia after the Poles had been defeated in January 1626. By April, Maria Eleonora found she was again pregnant. No risks were taken this time and the astrologers predicted the birth of a son and heir. During a lull in the warfare, Gustavus Adolphus hurried back to Stockholm to await the arrival of the baby. The birth was a difficult one. On 7 December, a baby was born with a fleece (lanugo), which enveloped it from its head to its knees, leaving only its face, arms and lower part of its legs free. Moreover, it had a large nose and was covered with hair. Thus, it was assumed the baby was a boy, and so the King was told. Closer inspection, however, determined that the baby was a girl. Gustavus Adolphus' half-sister Catherine informed him that the child was a girl. She "carried the baby in her arms to the king in a condition for him to see and to know and realise for himself what she dared not tell him". Gustavus Adolphus remarked: "She is going to be clever, for she has taken us all in." His disappointment did not last long, and he decided that she would be called Christina after his mother. He gave orders for the birth to be announced with all the solemnity usually accorded to the arrival of a male heir. This seems to indicate that Gustavus Adolphus, at the age of 33, had little hope of having other children. Maria Eleonora's state of health seems to be the most likely explanation for this. Her later portraits and actions, however, do not indicate that she was physically fragile.  Shortly after the birth, Maria Eleonora was in no condition to be told the truth about the baby's sex, and the king and court waited several days before breaking the news to her. She screamed: "Instead of a son, I am given a daughter, dark and ugly, with a great nose and black eyes. Take her from me, I will not have such a monster!" She may have suffered from a post-natal depression. In her agitated state, the queen tried to injure the child.  In Christina's early childhood, she repeatedly met with accidents. Once a beam fell mysteriously upon the cradle. Another time, she fell from a flight of stairs, apparently by accident. On another occasion the nursemaid was blamed for dropping the baby onto a stone floor, injuring a shoulder that ever afterwards remained a little crooked.  In the year after Christina's birth, Maria Eleonora was described as being in a state of hysteria owing to her husband's absences. In 1632 Gustavus Adolphus described his wife as being "a very sick woman". There was some excuse for her; she had lost three babies and still felt herself an isolated foreigner in a hostile land, even more so after 1627 when her brother joined Sweden's enemies. Meanwhile, her husband's life was constantly in danger when he was on campaign. In 1627 Gustavus Adolphus was both ill and wounded. Two years later he had a narrow escape at Stuhm.  Gustavus Adolphus was devoted to his daughter and tried to raise Christina like a boy. At the age of two, she clapped her hands and laughed with joy when the great cannons of Kalmar Castle boomed out the royal salute. Afterwards, Gustavus Adolphus often took his daughter with him to military reviews. Maria Eleonora showed little affection for her daughter and was not allowed any influence in Christina's upbringing. The princess was placed in the care of Gustavus Adolphus' half-sister Catherine and the Chancellor Axel Oxenstierna.  In 1630 Gustavus Adolphus concluded that Habsburg designs for Baltic supremacy threatened Sweden's very existence and also its religious freedom. Before he left to join the Thirty Years War, he discussed a possible regency with members of the government and admitted to them that his wife was "a miserable woman". Even so, Gustavus Adolphus could not bring himself to nominate a regency council in which her name did not appear. To Axel Oxenstierna, he confessed: "If anything happens to me, my family will merit your pity [..], the mother lacking in common sense, the daughter a minor - hopeless, if they rule, and dangerous, if others come to rule over them."

Widowhood.

During the next two years Gustavus Adolphus marched across a devastated Germany, conquering Pomerania and Mecklenburg. In early November 1632 he went to Erfurt to say goodbye to Maria Eleonora, who had been in Germany since the previous winter. In the Battle of Lützen, the 37-year-old Gustavus Adolphus was shot in the back. He fell and was dragged for some distance by his horse. He managed to free himself from the stirrup, but while lying on the ground "The Lion of the North" was killed by another shot through his head. By nightfall both armies were exhausted, but Bernard of Saxe-Weimar and the Swedes had captured all the Imperial artillery and were in possession of the key position. The king's body was found lying face downwards in the mud, plundered of everything but his shirt.  Maria Eleonora was not included in the regency government during the minority of her daughter, as the council of the state did not consider her suitable as regent. The king had never actually left any instructions that she should not be included in the case of a minor regency, but they supported their grounds for excluding her by the claim that the late king had said to them that she should never be entrusted with matters of state, though he never left any papers to confirm this. When she was informed that the regency government had been formed in May 1633 and that she had been excluded from it, Maria Eleonora was reportedly offended, and pointed out that her late mother-in-law, Christina of Holstein-Gottorp, had served as regent during the minority of her late spouse. In reply, however, the representative of the regency council, Gabriel Gustafsson Oxenstierna, responded that her information of the regency of queen dowager Christina was highly exaggerated, and that Sweden actually had no tradition to include queen dowagers in minor regencies. This was in fact a lie: not only had the queen dowager Christina in fact been regent, but king Gustav I of Sweden had proclaimed his queen Margaret Leijonhufvud regent in case of a minor regency in 1544, and John III of Sweden had provided for such a regency for both his first queen, Catherine Jagiellon, as well as for his second, Gunilla Bielke. Maria Eleonora, however, accepted the response, and declared that she would satisfied to entrust politics to others and to be in control of the custody of her daughter.  In 1633 Maria Eleonora returned to Sweden with the embalmed body of her husband. In Nyköping, 7-year-old Queen Christina came in solemn procession to the ship to receive her mother. Later she wrote: "I embraced the queen my mother, she drowned me with her tears and practically smothered me in her arms." For more than a year Maria Eleonora condemned Christina to a mourning seclusion in rooms draped with black and lit by candles day and night, from which every ray of light was excluded. She made her daughter sleep with her in a bed over which her father's heart was hung in a golden casket. Things were made worse by Maria Eleonora's continual weeping. Christina, who also was somewhat malformed with one shoulder higher than the other, also detested her mother's dwarfs and buffoons. She became seriously ill; an ulcer appeared on her left breast, causing her terrible pain and a high fever until it burst. In the summer of 1634 the funeral procession finally wound its way to Stockholm. Queen Christina later wrote about her mother: "She carried out her role of mourning to perfection."  Maria Eleonora had plunged into a prolonged period of emotional dysregulation due to grief. She found it more difficult than ever to conceal her dislike of Swedish "rocks and mountains, the freezing air, and all the rest of it". During the rest of her life she preserved the memory of her husband, weeping for hours and even days on end. When the regency council tried to separate Christina from her mother, Maria Eleonora wept and protested so bitterly that nothing was done.

Relationship with Queen Christina.

In 1636 Maria Eleonora was taken to Gripsholm castle and officially lost her parental rights to her daughter, because at times she was completely out of her mind. In 1639 a letter written by her and intended for Sweden's archenemy, the King Christian IV of Denmark, was intercepted. After a summons, Maria Eleonora appeared at her daughter's court in a flood of tears in the summer of 1640. Queen Christina, 13 years old, reasoned with her mother and dissuaded her from taking up residence at Nyköping near Denmark. Afterwards, Maria Eleonora returned to Gripsholm. To undertake one of her periodic fasts, she retired to the seclusion of her own apartment, accompanied by only one of her ladies-in-waiting, Anna Sofia von Bülow. Maria Eleonora wrote regularly to her daughter Christina. She and her German court wanted to leave their exile at Gripsholm castle. Christina replied tactfully, knowing that the Council would not permit the queen mother any leave. Eventually her mother asked to leave Sweden altogether. Christina invited her to Stockholm, attempting to persuade her to stay in the country. At night the two ladies let themselves down from a window and were rowed in a boat to the other side of the nearby lake, where a carriage was waiting for them. They drove to Nyköping, where they boarded a Danish ship. King Christian IV had intended the ship to take her home to Brandenburg, but she convinced the captain to bring her to Denmark instead. She was well received by the Danish king, but Maria Eleonora wanted to go home to Brandenburg. The electoral prince there demanded financial compensation from Sweden, where on the contrary the Council expected to withdraw her appanage as well as her properties. Finally the teenage Christina succeeded in negotiating a certain alimony for her mother, adding to this from her own purse.  In Denmark, Maria Eleonora became the guest of King Christian IV. The Elector George William refused to receive his sister in Brandenburg, so Maria Eleonora had to wait until his death in December that year before her nephew gave her permission to visit Brandenburg. Still, the new Elector insisted that Sweden should provide for his aunt's upkeep. She received a small pension of 30,000 écus a year. After a while Maria Eleonora surprisingly started to long for Sweden, and in 1648 she returned. Queen Christina went to meet her mother's ship. It was delayed by a storm and the young queen slept in the open for two nights and contracted a fever, which kept her in bed for some days. In October 1650 Maria Eleonora attended her daughter's postponed coronation ceremony. Christina then bought the newly erected castle "Makalös" ("Unequalled") for her, close to the royal castle in Stockholm. It would have been enormously expensive, but Christina never paid. Instead she handed it back in 1652.  In June 1654, Christina shocked everyone when she decided to abdicate in favour of her cousin Charles Gustav. Maria Eleonora had grave doubts about her daughter's abdication and its possible effect upon her own finances. Christina and Charles Gustav visited her at Nyköping in April 1654 and promised the Queen Dowager that she would be provided for. Christina abdicated June 5, 1654. Maria Eleonora died in March 1655. At that time, ex-Queen Christina was living in Brussels; she converted to Catholicism in December 1655.

Maria Eleonora of Brandenburg (11 November 1599 – 28 March 1655) was a German princess and Queen of Sweden as the consort of King Gustav II Adolph ("Gustavus Adolphus").

她的父亲是勃兰登堡选帝,约翰·西吉斯蒙德,她的母亲是普鲁士公爵阿尔伯特·弗雷德里克的女儿,普鲁士女大公安娜。


Overview.

Early expeditions.

Before the Little Ice Age (late Middle Ages to the 19th century), Norwegian Vikings sailed as far north and west as Ellesmere Island, Skraeling Island and Ruin Island for hunting expeditions and trading with the Inuit and people of the Dorset culture who already inhabited the region. Between the end of the 15th century and the 20th century, colonial powers from Europe dispatched explorers in an attempt to discover a commercial sea route north and west around North America. The Northwest Passage represented a new route to the established trading nations of Asia.  England called the hypothetical northern route the "Northwest Passage". The desire to establish such a route motivated much of the European exploration of both coasts of North America, also known as the New World. When it became apparent that there was no route through the heart of the continent, attention turned to the possibility of a passage through

Potential as a shipping lane.

In the 21st century, major changes to the ice pack due to climate change have stirred speculation that the passage may become clear enough of ice to permit safe commercial shipping for at least part of the year. On August 21, 2007, the Northwest Passage became open to ships without the need of an icebreaker. According to Nalan Koc of the Norwegian Polar Institute, this was the first time the Passage has been clear since they began keeping records in 1972. The Northwest Passage

Routes.

The Northwest Passage includes three sections:  Many attempts were made to find a salt water exit west from Hudson Bay, but the Fury and Hecla Strait in the far north is blocked by ice. The eastern entrance and main axis of the northwest passage, the Parry Channel, was found in 1819. The approach from the west through

Extent.

The International Hydrographic Organization defines

Historical expeditions.

As a result of their westward explorations and their settlement of Greenland, the Vikings sailed as far north and west as Ellesmere Island, Skraeling Island for hunting expeditions and trading with Inuit groups. The subsequent arrival of the Little Ice Age is thought to have been one of the reasons that European seafaring into the Northwest Passage ceased until the late 15th century.

Strait of Anián.

In 1539, Hernán Cortés commissioned Francisco de Ulloa to sail along the Baja California Peninsula on the western coast of North America. Ulloa concluded that the Gulf of California was the southernmost section of a strait supposedly linking the Pacific with the Gulf of Saint Lawrence. His voyage perpetuated the notion of the Island of California and saw the beginning of a search for the Strait of Anián.  The strait probably took its name from Ania, a Chinese province mentioned in a 1559 edition of Marco Polo's book;

Northern Atlantic.

The first recorded attempt to discover the Northwest Passage was the east-west voyage of John Cabot in 1497, sent by Henry VII in search of a direct route to the Orient. In 1524, Charles V sent Estêvão Gomes to find a northern Atlantic passage to the Spice Islands. An English expedition was launched in 1576 by Martin Frobisher, who took three trips west to what is now the Canadian Arctic in order to find the passage. Frobisher Bay, which he first charted, is named after him.  As part of another expedition, in July 1583 Sir Humphrey Gilbert, who had written a treatise on the discovery of the passage and was a backer of Frobisher, claimed the territory of Newfoundland for the English crown. On August 8, 1585, the English explorer John Davis entered Cumberland Sound, Baffin Island.  The major rivers on the east coast were also explored in case they

Northern Pacific.

Most Northwest Passage expeditions originated in Europe or on the east coast of North America, seeking to traverse the Passage in the westbound direction. Some progress was made in exploring the western reaches of the imagined passage.  In 1728 Vitus Bering, a Danish Navy officer in Russian service, used the strait first discovered by Semyon Dezhnyov in 1648 but later accredited to and named after Bering (the Bering Strait). He concluded that North America and Russia were separate land masses by sailing between them. In 1741 with Lieutenant Aleksei Chirikov, he explored seeking further lands beyond Siberia. While they were separated, Chirikov discovered several of the Aleutian Islands while Bering charted the Alaskan region. His ship was wrecked off the Kamchatka Peninsula, as

Cook and Vancouver.

In 1776, Captain James Cook was dispatched by the Admiralty in Great Britain on an expedition to explore the Passage. A 1745 act, when extended in 1775, promised a £20,000 prize for whoever discovered the passage. Initially the Admiralty had wanted Charles Clerke to lead the expedition, with Cook (in retirement following his exploits in the Pacific) acting as a consultant. However, Cook had researched Bering's expeditions, and the Admiralty ultimately placed their faith in the veteran explorer to lead, with Clerke accompanying him.  After journeying through the Pacific, to make an attempt from the west, Cook began at Nootka Sound in April 1778. He headed north along the coastline, charting the lands and searching for the

19th century.

In the first half of the 19th century, some parts of the Northwest Passage (north of the Bering Strait) were explored separately by many expeditions, including those by John Ross, Elisha Kent Kane, William Edward Parry, and James Clark Ross; overland expeditions were also led by John Franklin, George Back, Peter Warren Dease,

Franklin expedition.

In 1845, a lavishly equipped two-ship expedition led by Sir John Franklin sailed to the Canadian Arctic to chart the last unknown swaths of the Northwest Passage. Confidence was high, as they estimated there was less than remaining of unexplored Arctic mainland coast. When the ships failed to return, relief expeditions and search parties explored the Canadian Arctic, which resulted in a thorough charting of the region, along with a possible passage. Many artifacts from the expedition were found over the next century and a half, including notes that the ships were ice-locked in 1846 near King William Island, about halfway through the passage, and unable to break free. Records showed Franklin died in 1847 and Captain Francis Rawdon Moira Crozier took over command. In 1848 the expedition

McClure expedition.

During the search for Franklin, Commander Robert McClure and his crew in traversed the Northwest Passage from west to east in the years 1850 to 1854, partly by ship and partly by sledge. McClure started out from England in December 1849, sailed the Atlantic Ocean south to Cape Horn and entered the Pacific Ocean. He sailed the Pacific north and passed through the Bering Strait, turning east at that point and reaching Banks Island.  McClure's ship was trapped in the ice for three winters near Banks Island, at the western end of Viscount Melville Sound. Finally McClure and his crew—who were by that time dying of starvation—were

John Rae.

The expeditions by Franklin and McClure were in the tradition of British exploration: well-funded ship expeditions using modern technology, and usually including British Naval personnel. By contrast, John Rae was an employee of the Hudson's Bay Company, which operated a far-flung trade network and drove exploration of the Canadian North. They adopted a pragmatic approach and tended to be land-based. While Franklin and

Amundsen expedition.

The first explorer to conquer the Northwest Passage solely by ship was the Norwegian explorer Roald Amundsen. In a three-year journey between 1903 and 1906, Amundsen explored the passage with a crew of six. Amundsen, who had sailed to escape creditors seeking to stop the expedition, completed the voyage in the converted 45 net register tonnage () herring boat "Gjøa". "Gjøa" was much smaller than vessels used by other Arctic expeditions and had a shallow draft. Amundsen intended to hug the shore, live off the limited resources of the land and sea through which he was to travel, and had determined that he needed to have a tiny crew to make this work. (Trying to support much larger crews had contributed to

Later expeditions.

The first traversal of the Northwest Passage via dog sled was accomplished by Greenlander Knud Rasmussen while on the Fifth Thule Expedition (1921–1924). Rasmussen and two Greenland Inuit travelled from the Atlantic to the Pacific over the course of 16 months via dog sled.  Canadian Royal Canadian Mounted Police officer Henry Larsen was the second to sail the passage, crossing west to east, leaving Vancouver on June 23, 1940 and arriving at Halifax on October 11, 1942. More than once on this trip, he was uncertain whether, a Royal Canadian Mounted Police "ice-fortified" schooner, would survive the pressures of the sea ice. At one point, Larsen wondered "if we had come this far only to be crushed like a nut on a shoal and then buried by the ice." The ship and all but one of her crew survived the winter on Boothia Peninsula. Each of the men on the trip was awarded a medal by Canada's sovereign, King George VI, in recognition of this feat of Arctic navigation.  Later in 1944, Larsen's return trip was far more swift than his first. He made the trip in 86 days to sail back from Halifax, Nova Scotia, to Vancouver, British Columbia. He set a record for traversing the route in a single season. The ship, after extensive upgrades, followed a more northerly, partially uncharted route.  In 1954, completed the east-to-west transit, under the command of Captain O.C.S. Robertson, conducting hydrographic soundings along the route. She was the first warship (and the first deep draft ship) to transit the Northwest Passage and the first warship to circumnavigate North America. In 1956, HMCS "Labrador" again completed the east-to-west transit, this time under the command of Captain T.C. Pullen.  On July 1, 1957, the United States Coast Guard cutter departed in company with and to search for a deep-draft channel through the Arctic Ocean and to collect hydrographic information. The US Coast Guard Squadron was escorted through Bellot Strait and the Eastern Arctic by HMCS "Labrador". Upon her return to Greenland waters, "Storis" became the first U.S.-registered vessel to circumnavigate North America. Shortly after her return in late 1957, she was reassigned to her new home port of Kodiak, Alaska.  In

International waters dispute.

The Canadian government classifies the waters of the Northwest Passage in the Canadian Arctic Archipelago, as internal waters of Canada as per the United Nations Convention on the Law of the Sea and by the precedent in the drawing of baselines for other archipelagos, giving Canada the right to bar transit through these waters. Some maritime nations, including the United States and some of the European Union, claim these waters to be an international strait, where foreign vessels have the right of "transit passage". In such a regime, Canada would have the right to enact fishing and environmental regulation, and fiscal and smuggling laws, as well as laws intended for the safety of shipping, but not the right to close the passage. If the passage's deep waters become completely ice-free in summer months, they will be particularly enticing for supertankers that are too big to pass through the Panama Canal and must otherwise navigate around the tip of South America.  The dispute between Canada and the United States arose in 1969 with the trip of the U.S. oil tanker through the Arctic Archipelago. The prospect of more American traffic headed to the Prudhoe Bay Oil Field made the Canadian government realize that political action was required.  In 1985, the U.S. Coast Guard icebreaker passed through from Greenland to Alaska; the ship submitted to inspection by the Canadian Coast Guard before passing through, but the event infuriated the Canadian public and resulted in a diplomatic incident. The United States government, when asked by a Canadian reporter, indicated that they did not ask for permission as they insist that the waters were an international strait. The Canadian government issued a declaration in 1986 reaffirming Canadian rights to the waters. The United States refused to recognize the Canadian claim. In 1988 the governments of Canada and the United States signed an agreement, "Arctic Cooperation",

Thinning ice cover and the Northwest Passage.

In the summer of 2000, two Canadian ships took advantage of thinning summer ice cover on the Arctic Ocean to make the crossing. It is thought that climate change is likely to open the passage for increasing periods, making it potentially attractive as a major shipping route. However, the passage through the Arctic Ocean would require significant investment in escort vessels and staging ports, and it would remain seasonal. Therefore, the Canadian commercial marine transport industry does not anticipate the route as a viable alternative to the Panama Canal within the next 10 to 20 years (as of 2004).  On September 14, 2007, the European Space Agency stated that ice loss that year had opened up the historically impassable passage, setting a new low of ice cover as seen in satellite measurements which went back to 1978. According to the Arctic Climate Impact Assessment, the latter part of the 20th century and the start of the 21st had seen marked shrinkage of ice cover. The extreme loss in 2007 rendered the passage "fully navigable". However, the ESA study was based only on analysis of satellite images and could in practice not confirm anything about the actual navigation of the waters of the passage. ESA suggested the passage would be navigable "during reduced ice cover by multi-year ice pack" (namely sea ice surviving one or more summers) where previously any traverse of the route had to be undertaken during favourable seasonable climatic conditions or by specialist vessels or expeditions. The agency's report speculated that the conditions prevalent in 2007 had shown the passage may "open" sooner than expected. An expedition in May 2008 reported that the passage was not yet continuously navigable even by an icebreaker and not yet ice-free.  Scientists at a meeting of the American Geophysical Union on December 13, 2007, revealed that NASA satellites observing the western Arctic showed a 16% decrease in cloud coverage during the summer of 2007 compared to 2006. This would have the effect of allowing more sunlight to penetrate Earth's atmosphere and warm the Arctic Ocean waters, thus melting sea ice and contributing to the opening the Northwest Passage.  In 2006 the cruise liner MS "Bremen" successfully ran the Northwest Passage, helped by satellite images telling where sea ice was.  On November 28, 2008, the Canadian Broadcasting Corporation reported that the Canadian Coast Guard confirmed the first commercial ship sailed through the Northwest Passage. In September 2008,, owned by Desgagnés Transarctik Inc. and, along with the Arctic Cooperative, is part of Nunavut Sealift and Supply Incorporated (NSSI), transported cargo from Montreal to the hamlets of Cambridge Bay, Kugluktuk, Gjoa Haven, and Taloyoak. A member of the crew is reported to have claimed that "there was no ice whatsoever". Shipping from the east was to resume in the fall of 2009. Although sealift is an annual feature of the Canadian Arctic this is the first time that the western communities have been serviced from the east. The western portion of the Canadian Arctic is normally supplied by Northern Transportation Company Limited (NTCL) from Hay River, and the eastern portion by NNSI and NTCL from Churchill and Montreal.  In January 2010, the ongoing reduction in the Arctic sea ice led telecoms cable specialist Kodiak-Kenai Cable to propose the laying of a fiberoptic cable connecting London and Tokyo, by way of the Northwest Passage, saying the proposed system would nearly cut in half the time it takes to send messages from the United Kingdom to Japan.  In September 2013, the first large ice strengthened sea freighter, "Nordic Orion", used the passage.  In 2016 a new record was set when the cruise ship "Crystal Serenity" transited with 1,700 passengers and crew. "Crystal Serenity" is the largest cruise ship to navigate the Northwest Passage. Starting on August 10, 2016, the ship sailed from Vancouver to New York City, taking 28 days for the journey.

Transfer of Pacific species to North Atlantic.

Scientists believe that reduced sea ice in the Northwest Passage has permitted some new species to migrate across the Arctic Ocean. The gray whale "Eschrichtius robustus" has not been seen in the Atlantic since it was hunted to extinction there in the 18th century, but in May 2010, one such whale turned up in the Mediterranean. Scientists

The Northwest Passage (NWP) is the sea route to the Pacific Ocean through the Arctic Ocean, along the northern coast of North America via waterways through the Canadian Arctic Archipelago. The eastern route along the Arctic coasts of Norway and Siberia is accordingly called the Northeast Passage (NEP).

西北水道,或译西北航道(英语:英语:Northwest Passage),是一条穿越加拿大北极群岛,连接大西洋和太平洋的航道。


Reign.

He was born Leo Marcellus in Thracia or in Dacia Aureliana province in the year 401 to a Thraco-Roman family. His Dacian origin is mentioned by Candidus Isaurus, while John Malalas believes that he was of Bessian stock. He served in the Roman army, rising to the rank of "comes". Leo was the last of a series of emperors placed on the throne by Aspar, the Alan serving as commander-in-chief of the army, who thought Leo would be an easy puppet ruler. Instead, Leo became more and more independent from Aspar, causing tension that would culminate in the assassination of the latter.  Leo's coronation as emperor on 7 February 457, was the first known to involve the Patriarch of Constantinople. Leo I made an alliance with the Isaurians and was thus able to eliminate Aspar. The price of the alliance was the marriage of Leo's daughter to Tarasicodissa, leader of the Isaurians, who, as Zeno, became emperor in 474. In 469, Aspar attempted to assassinate Zeno and very nearly succeeded. Finally, in 471, Aspar's son Ardabur was implicated in a plot against Leo but was killed by palace eunuchs acting on Leo's orders.  Leo sometimes overestimated his abilities and made mistakes that threatened the internal order of the Empire. The Balkans were ravaged by the Ostrogoths, after a disagreement between the Emperor and the young chief Theodoric the Great, who had been raised at Leo's court in Constantinople, where he was steeped in Roman government and military tactics. There were also some raids by the Huns. However, these attackers were unable to take Constantinople thanks to the walls, which had been rebuilt and reinforced in the reign of Theodosius II and against which they possessed no suitable siege engines.  Leo's reign was also noteworthy for his influence in the Western Roman Empire, marked by his appointment of Anthemius as Western Roman emperor in 467. He attempted to build on this political achievement with an expedition against the Vandals in 468, which was defeated due to the arrogance of Leo's brother-in-law Basiliscus. This disaster drained the Empire of men and money. Procopius estimated the costs of the expedition to be 130,000 pounds of gold; John the Lydian estimated the costs to be 65,000 pounds of gold and 750,000 pounds of silver. The expedition consisted of 1,113 ships carrying 100,000 men; 600 of these ships were lost during the expedition. After this defeat, the Vandals raided Greek coasts until a costly peace agreement was signed between Leo and Genseric.  Leo became very unpopular in his last days as Emperor for abolishing any non-religious celebration or event on Sundays.  Leo died of dysentery at the age of 73 on 18 January 474.

Marriage and children.

Leo and Verina had three children. Their eldest daughter Ariadne was born prior to the death of Marcian (reigned 450 – 457). Ariadne had a younger sister, Leontia. Leontia was first betrothed to Patricius, a son of Aspar, but their engagement was probably annulled when Aspar and another of his sons, Ardabur, were assassinated in 471. Leontia then married Marcian, a son of Emperor Anthemius and Marcia Euphemia. The couple led a failed revolt against Zeno in 478–479. They were exiled to Isauria following their defeat.  An unknown son was born in 463. He died five months following his birth. The only sources about him are a horoscope by Rhetorius and a hagiography of Daniel the Stylite.  The "Georgian Chronicle", a 13th-century compilation drawing from earlier sources, reports a marriage of Vakhtang I of Iberia to Princess Helena of Byzantium, identifying her as a daughter of the predecessor of Zeno. This predecessor was probably Leo I, the tale attributing a third daughter to Leo. Cyril Toumanoff identified two children of this marriage: Mithridates of Iberia; and Leo of Iberia. This younger Leo was father of Guaram I of Iberia. The accuracy of the descent is unknown.

Leo I (; 401 – 18 January 474) was Eastern Roman emperor from 457 to 474. A native of Dacia Aureliana near historic Thrace, he was known as Leo the Thracian (Greek: "Leōn ho Thrax").

利奥一世(;401年-474年),拜占庭帝国皇帝。拜占庭的色雷斯总督。


History.

The name "Belgorod" (Белгород) in Russian literally means "White city", compounding the sememes "" ("bely", "white, light") and "" ("gorod", "town, city"). The city thus acquired its name because the region was rich in limestone. Etymologically, the name corresponds to other Slavic city-names of identical meaning: Belgrade, Belogradchik, Białogard, Biograd, Bilhorod, and Bilhorod-Dnistrovskyi.  Records first mention the settlement in 1237, when the Mongol-led army of Batu Khan ravaged it. It is unclear whether this Belgorod stood on the same site as the current city. In 1596 Tsar Feodor Ioannovich of Russia ordered its re-establishment as one of numerous forts set up to defend Muscovy's Southern borders from the Crimean Tatars. In the 17th century Belgorod suffered repeatedly from Tatar incursions, against which Russia built (from 1633 to 1740) an earthen wall, with twelve forts, extending upwards of from the Vorskla in the west to the Don in the east, and called the. In 1666 the Moscow Patriarchate established an archiepiscopal see in the town. After the Russian border moved south following successful wars against the Polish–Lithuanian Commonwealth in the second half of the 17th century, the fortress fell into disrepair; the town became part of the Kursk Governorate.  Tsar Peter the Great visited Belgorod on the eve of the Battle of Poltava (1709). A dragoon regiment had its base in the town until 1917.  Ioasaph of Belgorod, an 18th-century bishop of Belgorod and Oboyanska, became widely venerated as a miracle worker and was glorified as a saint of the Russian Orthodox Church in 1911.

20th century.

Soviet power was established in the city on 26 October (November 8), 1917. On 10 April 1918, troops of the Imperial German Army occupied Belgorod. After the conclusion of the Brest-Litovsk peace treaty of 9 February 1918 the demarcation line passed to the north of the city. Belgorod became part of the newly proclaimed Ukrainian People's Republic (February to May 1918) and Ukrainian State headed by Hetman Pavlo Skoropadskyi.  On 20 December 1918, after the overthrow of German-backed Skoropadskyi, the Soviet Red Army regained control over the city, which became part of the RSFSR. From 24 December 1918 to 7 January 1919, the Provisional Workers' and Peasants' Government of Ukraine, then led by General Georgy Pyatakov, was based in Belgorod. The city served as the temporary capital of the Ukrainian People's Republic. From 23 June to 7 December 1919 the Volunteer Army occupied the town as part of White-controlled South Russia.  From September 1925 the territorial 163rd Infantry Regiment of the 55th Infantry Division of Kursk was stationed in Belgorod. In September 1939 it was deployed to the 185th Infantry Division.  On 2 March 1935, the Presidium of the Central Executive Committee of the Soviet Union decided to allocate the city of Belgorod, Kursk region, into an independent administrative unit directly subordinate to the Kursk Regional Executive Committee.  The German Wehrmacht occupied Belgorod from 25 October 1941 to 9 February 1943. The Germans re-captured it on 18 March 1943 in the final move of the Third Battle of Kharkov. On 12 July 1943, during the Battle of Kursk, the largest tank battle in world history took place near Prokhorovka, and Red Army definitively retook the city on 5/6 August 1943. The Belgorod Diorama is one of the World War II monuments commemorating the event.  In 1954 the city became the administrative center of Belgorod Oblast. From this time the rapid development of the city as a regional center began.  Belgorod is an administrative, industrial and cultural center of Belgorod Oblast, established in 1954. The major educational centers of the city are Belgorod State University, the Belgorod Technological University, the, and the Financial Academy.  Belgorod Drama Theater is named after the famous 19th-century actor, Mikhail Shchepkin, who was born in this region.  On 22 April 2013, a mass shooting occurred at approximately 2:20 PM Moscow time on a street in Belgorod. The shooter, identified as 31-year-old Sergey (Sergei) Pomazun (), opened fire with a semi-automatic rifle on several people at a gun store and on a sidewalk, killing all six people whom he hit: three people at the store and three passers-by, including two teenage girls. Pomazun was later apprehended after an extensive day-long manhunt; during his arrest, he wounded a policeman with a knife. He was sentenced to life in prison on 23 August 2013.

Administrative and municipal status.

Belgorod is the administrative center of the oblast. Within the framework of administrative divisions, it is incorporated as the city of oblast significance of Belgorod—an administrative unit with status equal to that of the districts. As a municipal division, the city of oblast significance of Belgorod is incorporated as Belgorod Urban Okrug.

City divisions.

For administrative purposes, Belgorod is divided into two city okrugs:

Climate.

Belgorod's climate is humid continental (Köppen climate classification "Dfb" slightly cooler than "Dfa") featuring moderate precipitation. Winters are rather cold and changeable with frequent warmings followed by rains. Temperatures may occasionally fall below for about one week or more. Summer is warm and either humid and rainy or hot and droughty. Autumn is mild and rainy. The Belgorod reservoirs get covered with ice by the end of November or the beginning of December, and the ice layer typically lasts until March or April.

Transportation.

Since 1869, there has been a railway connection between Belgorod and Moscow. Belgorod is served by the Belgorod International Airport (EGO).

Trolleybus.

Length of trolley lines is over. Trolleybus city park consists of 150 pieces of equipment, mainly Russian-made trolley ZiU-682V, 2 units ZiU-683, operated since 1990, and 3 units ZiU-6205, 30 units "Optima", and also has one trolley Skoda-VSW -14Tr, which started operation in 1996. In 2002, the city administration purchased 15 new trolleybuses ZiU-682G, and in 2005 bought another 20 new trolleybuses ZiU-682G, and in 2011 - 30 trolleybuses Trolza-5275.05 "Optima", and in 2013 - 20 new trolleybuses ACSM-420.

Bus.

The city has two bus stations: Bus Belgorod, Belgorod- 2 Bus Terminal (located on the forecourt ), as well as bus stop complex Energomash. The Energomash bus station is mainly for commuting buses. From the bus station Belgorod-2 buses go mainly to nearby regional centers, and departure of buses in accordance with the arrival of trains. In 2019 Belgorod bought 20 new buses named Liaz.

Twin towns – sister cities.

Belgorod is twinned with:

Belgorod () is a city and the administrative center of Belgorod Oblast, Russia, located on the Seversky Donets River north of the border with Ukraine. Population:

电子健康纪录,又称为电子健康档案,简称英语:EHR (electronic health record),是电子化的个人健康纪录(病历、心电图、医疗影像等),电子健康纪录可以经由电脑或网络存取,可以包含现今与过去个人的健康资讯。除此之外,电子健康纪录也能够包括医学相关的参照资料、医疗处置、药物使用、人口统计资料、其他与非医疗的管理资料等等。然而,一个理想的电子健康纪录系统,现今还没有一个软件或是供应商所能够建置出来。


Desirable properties.

The ideal working fluid or often called refrigerant would have favorable thermodynamic properties, be noncorrosive to mechanical components, and be safe, including freedom from toxicity and flammability. It would not cause ozone depletion or climate change. Since different fluids have the desired traits in different degree, choice is a matter of trade-offs.  The desired thermodynamic properties are a boiling point somewhat below the target temperature, a high heat of vaporization, a moderate density in liquid form, a relatively high density in gaseous form, and a high critical temperature. Since boiling point and gas density are affected by pressure, refrigerants may be made more suitable for a particular application by appropriate choice of operating pressures.

Environmental issues.

A 2018 study by the nonprofit organization "Drawdown" put proper refrigerant management and disposal at the very top of the list of climate impact solutions, with an impact equivalent to eliminating over 17 years of US carbon dioxide emissions.  The inert nature of many haloalkanes, chlorofluorocarbons (CFC) and hydrochlorofluorocarbons (HCFC), particularly CFC-11 and CFC-12, made them preferred choices among refrigerants for many years because of their non-flammability and non-toxicity. However, their stability in the atmosphere and their corresponding global warming potential and ozone depletion potential raised concerns about their usage. This led to their replacement with HFCs and PFCs, especially HFC-134a, which are not-ozone depleting, and have lesser global warming potentials. However, these refrigerants still have global warming potentials thousands of times greater than CO. Therefore, they are now being replaced in markets where leaks are likely, by using a fourth generation of refrigerants, most prominently HFO-1234yf, trademarked by Chemours as Opteon-YF, which have global warming potentials much closer to that of CO.  In order from the highest to the lowest potential of ozone depletion are: Bromochlorofluorocarbon, CFC then HCFC.  New refrigerants were developed in the early 21st century that are safer for the environment, but their application has been held up due to concerns over toxicity and flammability.  Compared to halogenated refrigerants, hydrocarbons like isobutane (R-600a) and propane (R-290) offer several advantages: low cost and widely available, zero ozone depletion potential and very low global warming potential. They also have good energy efficiency, but are flammable and can form an explosive mixture with air if a leak occurs. Despite the flammability, they are increasingly used in domestic refrigerators. EU and US regulations set maximum charges of 57 or 150 grams of refrigerant, keeping the concentration in a standard kitchen below 20% of the lower explosive limit. The LEL can be exceeded inside the appliance, so no potential ignition sources can be present. Switches must be placed outside the refrigerated compartment or replaced by sealed versions, and only spark-free fans can be used. In 2010, about one-third of all household refrigerators and freezers manufactured globally used isobutane or an isobutane/propane blend, and this was expected to increase to 75% by 2020.

History.

Early mechanical refrigeration systems employed sulfur dioxide, methyl chloride or ammonia. Being toxic, sulfur dioxide and methyl chloride rapidly disappeared from the market with the introduction of CFCs. Occasionally, one may encounter older machines with methyl formate, methyl chloride, or dichloromethane (called carrene in the trade).  Chlorofluorocarbons were little used for refrigeration until better synthesis methods, developed in the 1950s, reduced their cost. Their domination of the market was called into question in the 1980s by concerns about depletion of the ozone layer.  Following legislative regulations on ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), substances used as substitute refrigerants such as perfluorocarbons (FCs) and hydrofluorocarbons (HFCs) have also come under criticism. They are currently subject to prohibition discussions on account of their harmful effect on the climate. In 1997, FCs and HFCs were included in the Kyoto Protocol to the Framework Convention on Climate Change. In 2006, the EU adopted a Regulation on fluorinated greenhouse gases, which makes stipulations regarding the use of FCs and HFCs with the intention of reducing their emissions. The provisions do not affect climate-neutral refrigerants. Hydrocarbons are seeing increasing use as refrigerants.

Uses.

Refrigerants such as ammonia (R717), carbon dioxide and non-halogenated hydrocarbons do not deplete the ozone layer and have no (ammonia) or only a low (carbon dioxide, hydrocarbons) global warming potential. They are used in air-conditioning systems for buildings, in sport and leisure facilities, in the chemical/pharmaceutical industry, in the automotive industry and above all in the food industry (production, storage, marine shipping, retailing). In these settings their toxicity is less a concern than in home equipment.  Emissions from automobile air conditioning are a growing concern because of their impact on climate change. From 2011 on, the European Union will phase out refrigerants with a global warming potential (GWP) of more than 150 in automotive air conditioning (GWP = 100 year warming potential of one kilogram of a gas relative to one kilogram of CO). This will ban potent greenhouse gases such as the refrigerant HFC-134a (also known as R-134a in North America) —which has a GWP of 1410—to promote safe and energy-efficient refrigerants.  One of the most promising alternatives is CO (R-744). Carbon dioxide is non-flammable, non-ozone depleting, has a global warming potential of 1. R-744 can be used as a working fluid in climate control systems for cars, residential air conditioning, hot water pumps, commercial refrigeration, and vending machines. R12 is compatible with mineral oil, while R134a is compatible with synthetic oil that contains esters. GM announced that it would start using "hydrofluoroolefin", HFO-1234yf, in all of its brands by 2013. Dimethyl ether (DME) is also gaining popularity as a refrigerant, but like propane, it is also dangerously flammable.  Some refrigerants are seeing rising use as recreational drugs, leading to an extremely dangerous phenomenon known as inhalant abuse.

Disposal.

Under Section 608 of the United States' Clean Air Act it is illegal to knowingly release refrigerants into the atmosphere. SNAP approved hydrocarbon substitutes (isobutane and propane: R600a, R441a and R290), ammonia and CO are exempt from the venting prohibition.  When refrigerants are removed they should be recycled to clean out any contaminants and return them to a usable condition. Refrigerants should never be mixed together outside of facilities licensed to do so for the purpose of producing blends. Some refrigerants must be managed as hazardous waste even if recycled, and special precautions are required for their transport, depending on the legislation of the country's government.  Various refrigerant reclamation methods are in use to recover refrigerants for reuse.

Refrigerants by class and R-number.

Refrigerants may be divided into three classes according to their manner of absorption or extraction of heat from the substances to be refrigerated:  The R-# numbering system was developed by DuPont corporation (which owned the Freon trademark), and systematically identifies the molecular structure of refrigerants made with a single halogenated hydrocarbon. The meaning of the codes is as follows: For example, R-134a has 2 carbon atoms, 2 hydrogen atoms, and 4 fluorine atoms, an empirical formula of tetrafluoroethane. The "a" suffix indicates that the isomer is unbalanced by one atom, giving 1,1,1,2-Tetrafluoroethane. R-134 (without the "a" suffix) would have a molecular structure of 1,1,2,2-Tetrafluoroethane.  The same numbers are used with an R- prefix for generic refrigerants, with a "Propellant" prefix (e.g., "Propellant 12") for the same chemical used as a propellant for an aerosol spray, and with trade names for the compounds, such as "Freon 12". Recently, a practice of using abbreviations HFC- for hydrofluorocarbons, CFC- for chlorofluorocarbons, and HCFC- for hydrochlorofluorocarbons has arisen, because of the regulatory differences among these groups.

Notable blends.

Below are some notable blended HFC mixtures. There exist many more (see list of refrigerants). All R-400 (R-4xx) and R-500 (R-5xx) hydroflurocarbons are blends, as noted above.

Air as a refrigerant.

Air has been used for residential, automobile, and piston- and turbine-powered aircraft air-conditioning and/or cooling. Air is not more widely used as a general-purpose refrigerant because there is no change of phase, and is therefore too inefficient to be practical in most applications. It has been suggested that with suitable compression and expansion technology, air can be a practical (albeit not the most efficient) refrigerant, free of the possibility of environmental contamination or damage, and almost completely harmless to plants and animals.  However, an explosion could result from vapors or atomized refrigerant-type compressor lubricating oils being compressed together with air, in a process similar to a diesel engine.

Water as a refrigerant.

Water—natural, non toxic, low cost, environmentally friendly, and widely available—is widely used in water cooling, and if evaporated in the process may be called a "refrigerant". Water also commonly serves as a heat transfer and storage material, and in large systems it may actually fill all of these roles. The simplest and lowest cost open-cycle cooling systems, known as swamp coolers in the south-west United States, do not even need power for a compressor, merely a blower fan, so humidified cooled air is simply vented into the living space. Portable free-standing units can be obtained at discount stores for less than $200. However, if these systems are improperly implemented the drawbacks are multiple and severe.  The total cooling power of the unit is limited by the fact that neither coolant nor air can be recirculated. If the cooling unit does not have a supply of fresh dry air and the waste air is not effectively vented, stagnant humid air will make the space more uncomfortable than if it were merely ventilated.  An additional limitation of such systems would be that if the air outside is already humid, cooling power is severely limited. This is why such units are not found in areas of frequent and high humidity, such as the south-east United States.  If the temperature outside is severely hot, above, the simple unit will not cool the air sufficiently for comfort even if the dew point outside is very low. In these instances more-complex systems such as two stage, indirect-direct or hybrid will be needed.  While all the drawbacks can be addressed in various ways, the complexity and initial cost of these systems increases to the point that the installation cost comes into competition with common refrigerant based direct cooling systems. At this price point, direct cooling systems are often chosen even though the long term energy cost of evaporative systems may be lower.

A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. In most cycles it undergoes phase transitions from a liquid to a gas and back again. Many working fluids have been used for such purposes. Fluorocarbons, especially chlorofluorocarbons, became commonplace in the 20th century, but they are being phased out because of their ozone depletion effects. Other common refrigerants used in various applications are ammonia, sulfur dioxide, and non-halogenated hydrocarbons such as propane.

-{zh-cn:制冷剂;zh-tw:冷媒;zh-hk:雪种;}-,又称-{zh-cn:冷媒;zh-tw:制冷剂;zh-hk:冷媒;}-、致冷剂、-{zh-cn:雪种;zh-tw:雪种;zh-hk:制冷剂;}-,是各种热机中借以完成能量转化的媒介物质。这些物质通常以可逆的相变(如气-液相变)来增大功率。如蒸汽引擎中的蒸汽、制冷机中的雪种等等。一般的蒸汽机在工作时,将蒸汽的热能释放出来,转化为机械能以产生原动力;而制冷机的雪种则用来将低温处的热量传动到高温处。


History.

RISC OS was originally released in 1987 as "Arthur 1.20". The next version,, became and was released in April 1989. RISC OS 3.00 was released with the A5000 in 1991, and contained many new features. By 1996, RISC OS had been shipped on over 500,000 systems.  Acorn officially halted work on the OS in January 1999, renaming themselves Element 14. In March 1999 a new company, RISCOS Ltd, licensed the rights to develop a desktop version of RISC OS from Element 14, and continued the development of RISC OS 3.8, releasing it as "RISC OS 4" in July 1999. Meanwhile, Element 14 had also kept a copy of RISC OS 3.8 in house, which they developed into NCOS for use in set-top boxes. In 2000, Element 14 sold RISC OS to Pace Micro Technology, who later sold it to Castle Technology Ltd.  In May 2001, RISCOS Ltd launched "RISC OS Select", a subscription scheme allowing users access to the latest RISC OS 4 updates. These upgrades are released as soft-loadable ROM images, separate to the ROM where the boot OS is stored, and are loaded at boot time. Select 1 was shipped in May 2002, with Select 2 following in November 2002 and the final release of Select 3 in June 2004. In the same month, RISC OS 4.39, dubbed "RISC OS Adjust", was released. RISC OS Adjust was a culmination of all the Select Scheme updates to date, released as a physical set of replaceable ROMs for the RiscPC and A7000 series of machines.  Meanwhile, in October 2002, Castle Technology released the "Acorn clone" Iyonix PC. This ran a 32-bit (in contrast to 26-bit) variant of RISC OS, named "RISC OS 5". RISC OS 5 is a separate evolution of RISC OS based upon the NCOS work done by Pace. The following year, Castle Technology bought RISC OS from Pace for an undisclosed sum. In October 2006, Castle announced a shared source license plan, managed by RISC OS Open Limited, for elements of "RISC OS 5".  In October 2018, RISC OS 5 was re-licensed under the Apache 2.0 license.

Supported hardware.

Versions of RISC OS run or have run on the following hardware.  RISC OS Open Limited adopted the 'even numbers are stable' version numbering scheme post version 5.14, hence some table entries above include two latest releases – the last stable one and the more recent development one.  A special cut down RISC OS Pico (for 16MiB cards and larger) styled to start up like a BBC Micro was released for BASIC's 50th anniversary.  RISC OS has also been used by both Acorn and Pace Micro Technology in various TV connected set-top boxes, sometimes referred to instead as NCOS.  RISC OS can also run on a range of computer system emulators that emulate the earlier Acorn machines listed above.

Features.

OS core.

The OS is single-user and employs cooperative multitasking (CMT). While most current desktop OSes use preemptive multitasking (PMT) and multithreading, remains with a CMT system. By 2003, many users had called for the OS to migrate to PMT. The OS memory protection is not comprehensive.  The core of the OS is stored in ROM, giving a fast bootup time and safety from operating system corruption. RISC OS 4 and 5 are stored in of flash memory, or as a ROM image on SD Card on single board computers such as the Beagleboard or Raspberry Pi, allowing the operating system to be updated without having to replace the ROM chip. The OS is made up of several modules. These can be added to and replaced, including soft-loading of modules not present in ROM at run time and on-the-fly replacement. This design has led to OS developers releasing rolling updates to their versions of the OS, while third parties are able to write OS replacement modules to add new features. OS modules are accessed via software interrupts (SWIs), similar to system calls in other operating systems.  Most of the OS has defined application binary interfaces (ABIs) to handle filters and vectors. The OS provides many ways in which a program can intercept and modify its operation. This simplifies the task of modifying its behaviour, either in the GUI, or deeper. As a result, there are several third-party programs which allow customising the OS look and feel.

File system.

The file system is volume-oriented: the top level of the file hierarchy is a volume (disc, network share) prefixed by the file system type. To determine file type, the OS uses metadata instead of file extensions. Colons are used to separate the file system from the rest of the path; the root is represented by a dollar (codice_1) sign and directories are separated by a full stop (codice_2). Extensions from foreign file systems are shown using a slash (codice_3 becomes codice_4). For example, codice_5 is the root of the disc named "HardDisc4" using the Advanced Disc Filing System (ADFS) file system. filetypes can be preserved on other systems by appending the hexadecimal type as 'codice_6' to filenames. When using cross-platform software, filetypes can be invoked on other systems by naming appending 'codice_7' to the filename under.  A file system can present a file of a given type as a volume of its own, similar to a loop device. The OS refers to this function as an image filing system. This allows transparent handling of archives and similar files, which appear as directories with some special properties. Files inside the image file appear in the hierarchy underneath the parent archive. It is not necessary for the archive to contain the data it refers to: some symbolic link and network share file systems put a reference inside the image file and go elsewhere for the data.  The file system abstraction layer API uses 32-bit file offsets, making the largest single file 4 GiB (minus 1 byte) long. However, prior to RISC OS 5.20 the file system abstraction layer and many RISC OS-native file systems limited support to 31 bits (just under 2 GiB) to avoid dealing with apparently negative file extents when expressed in two's complement notation.

File formats.

The OS uses metadata to distinguish file formats. Some common file formats from other systems are mapped to filetypes by the MimeMap module.

Kernel.

The RISC OS kernel is single-tasking (the cooperative multi-tasking is provided by the WindowManager module) and controls handling of interrupts, DMA services, memory allocation and the video display.

Desktop.

The WIMP interface is based on a stacking window manager and incorporates three mouse buttons (named "Select", "Menu" and "Adjust"), context-sensitive menus, window order control (i.e. send to back) and dynamic window focus (a window can have input focus at any position on the stack). The icon bar (Dock) holds icons which represent mounted disc drives, RAM discs, running applications, system utilities and docked: files, directories or inactive applications. These icons have context-sensitive menus and support drag-and-drop operation. They represent the running application as a whole, irrespective of whether it has open windows.  The GUI functions on the concept of files. The Filer, a spatial file manager, displays the contents of a disc. Applications are run from the Filer view and files can be dragged to the Filer view from applications to perform saves. Application directories are used to store applications. The OS differentiates them from normal directories through the use of an exclamation mark (also called a "pling" or "shriek") prefix. Double-clicking on such a directory launches the application rather than opening the directory. The application's executable files and resources are contained within the directory, but normally they remain hidden from the user. Because applications are self-contained, this allows drag-and-drop installing and removing.  The "Style Guide" encourages a consistent look and feel across applications. This was introduced in and specifies application appearance and behaviour. Acorn's own main bundled applications were not updated to comply with the guide until's "Select" release in 2001.

Font manager.

The outline font manager provides anti-aliasing of fonts. RISC OS was the first operating system to include such a feature, having included it since before January 1989. Since 1994, in RISC OS 3.5, it has been possible to use an outline anti-aliased font in the WindowManager for UI elements, rather than the bitmap system font from previous versions.  RISC OS 4 does not support Unicode but "RISC OS 5 provides a Unicode Font Manager which is able to display Unicode characters and accept text in UTF-8, UTF-16 and UTF-32. Other parts of the RISC OS kernel and core modules support text described in UTF-8."  Support for characters of RISC OS (and some other historic computers) was added to Unicode 13.0 (in 2020).

Bundled applications.

is delivered with several desktop applications in the form of pre-installed software.

Backward compatibility.

Limited software portability exists with subsequent versions of the OS and hardware. Single-tasking BBC BASIC applications often require only trivial changes, if any. Successive OS upgrades have raised more serious issues of backward compatibility for desktop applications and games. Applications still being maintained by their author(s) or others have sometimes historically been amended to provide compatibility.  The introduction of the RiscPC in 1994 and its later StrongARM upgrade raised issues of incompatible code sequences and proprietary squeezing (data compression). Patching of applications for the StrongARM was facilitated and Acorn's "UnsqueezeAIF" software unsqueezed images according to their AIF header. The incompatibilities prompted release by "The ARM Club" of its "Game On!" and "StrongGuard" software. They allowed some formerly incompatible software to run on new and upgraded systems. The version of the OS for the A9home prevented the running of software without an AIF header (in accord with Application Note 295) to stop "trashing the desktop".  The Iyonix PC () and A9home (custom ) saw further software incompatibility because of the deprecated addressing modes. Most applications under active development have since been rewritten. Static code analysis to detect only sequences can be undertaken using "ARMalyser". Its output can be helpful in making 32-bit versions of older applications for which the source code is unavailable. Some older 26-bit software can be run without modification using the Aemulor emulator.  Additional incompatibilities were introduced with newer ARM cores, such as ARMv7 in the BeagleBoard and ARMv8 in the. This includes changes to unaligned memory access in ARMv6/v7 and removal of the SWP instructions in ARMv8.

RISC OS is a computer operating system originally designed by Acorn Computers Ltd in Cambridge, England. First released in 1987, it was designed to run on the ARM chipset, which Acorn had designed concurrently for use in its new line of Archimedes personal computers. RISC OS takes its name from the reduced instruction set computer (RISC) architecture it supports.

最新的稳定版本运行在 ARMv3/ARMv4 RiscPC(或根据仿真通过VirtualAcorn或RPCEmu),ARMv5的Iyonix和ARMv7的Cortex-A8处理器 (如使用的BeagleBoard和Touch Book)。在2011年,一个移植的Cortex-A9 PandaBoard已宣布和树莓派在公众场合露面的开发版本可免费下载的候选发布版已跟进,这版本已免费提供树莓派用户。


Origin of the name.

The leaders of the nobles who signed a solemn league known as the Compromise of Nobles, by which they bound themselves to assist in defending the rights and liberties of the Netherlands against the civil and religious despotism of Philip II of Spain were Louis of Nassau, and Hendrick van Brederode. On 5 April 1566, permission was obtained for the confederates to present a petition of grievances, called the Request, to the regent, Margaret, Duchess of Parma. About 250 nobles marched to the palace accompanied by Louis of Nassau and Brederode. The regent was at first alarmed at the appearance of so large a body, but one of her councillors, Berlaymont, allegedly remarked "N'ayez pas peur Madame, ce ne sont que des gueux" (Fear not madam, they are only beggars). The appellation was not forgotten. In a speech at a great feast held by some 300 confederates at the Hotel Culemburg three days later, Brederode declared that if need be they were all ready to become beggars in their country's cause. Henceforward the name became a party title. The patriot party adopted the emblems of beggary, the wallet and the bowl, as trinkets to be worn on their hats or their girdles, and a medal was struck having on one side the head of Philip II, on the other two clasped hands with the motto "Fidèle au roy, jusqu'à porter la besace" ("Loyal to the King, up to carrying the beggar's pouch"). The original league of Beggars was short-lived, crushed by Alva, but its principles survived and were to be ultimately triumphant.  In the Dutch language the word "geuzennaam" is used for linguistic reappropriation: a pejorative term used with pride by the people called that way.

Sea Beggars.

In 1569 William of Orange, who had now openly placed himself at the head of the party of revolt, granted letters of marque to a number of vessels manned by crews of desperadoes drawn from all nationalities. Eighteen ships received letters of marque, which were equipped by Louis of Nassau in the French Huguenot port of La Rochelle, which they continued to use as a base. By the end of 1569, already 84 Sea Beggars ships were in action.  The sea beggars were powerful military units that made capturing coastal cities easy. These fierce privateers under the command of a succession of daring and reckless leaders, the best-known of whom is William de la Marck, Lord of Lumey, were called "Sea Beggars", "Gueux de mer" in French, or "Watergeuzen" in Dutch. At first they were content merely to plunder both by sea and land, carrying their booty to the English ports where they were able to refit and replenish their stores.  However, in 1572, Queen Elizabeth I of England abruptly refused to admit the Sea Beggars to her harbours. No longer having refuge, the Sea Beggars, under the command of Willem Bloys van Treslong, made a desperate attack upon Brielle, which they seized by surprise in the absence of the Spanish garrison on 1 April 1572. Encouraged by this success, they now sailed to Vlissingen, which was also taken by a "coup de main". The capture of these two towns prompted several nearby towns to declare for revolt, starting a chain reaction that resulted in the majority of Holland joining in a general revolt of the Netherlands, and is regarded as the real beginning of Dutch independence.  In 1573 the Sea Beggars defeated a Spanish squadron under the command of Admiral Bossu off the port of Hoorn in the Battle on the Zuiderzee. Mixing with the native population, they quickly sparked rebellions against Duke of Alba in town after town and spread the resistance southward.  Some of the forefathers of the Dutch naval heroes began their naval careers as Sea Beggars, such as Evert Heindricxzen, the grandfather of Cornelis Evertsen the Elder.

Geuzen symbols.

As part of a propaganda campaign including prints, pamphlets and much else, many Geuzen medals were created as badges of affiliation, using a wide range of symbolism, including that associated with the Ottoman Empire. William I of Orange sought Ottoman assistance against the Spanish king Philip II. The "Geuzen" were expressing their anti-Spanish and anti-Catholic sentiments. They considered the Turks to be less threatening than the Spaniards. During the years between 1579 and 1582, representatives from Grand Vizier Sokollu Mehmed Paşa travelled several times from Istanbul to Antwerp.  There were, in fact, objective grounds for such an alliance. At the same time that the Dutch rebels were conducting their raids on Spanish shipping, the Ottoman Empire was involved in its own naval war with Spain, culminating in the 1571 Battle of Lepanto. Obviously, facing Spain with a coordinated double-pronged naval challenge, by the Ottomans in the Mediterranean and the Dutch in north European waters, would be to the advantage of both of Spain's foes.  The slogan "Liever Turks dan Paaps" seems to have been largely rhetorical, and their beggars medals in the form of a half moon were meant symbolically. The Dutch hardly contemplated life under the Sultan. Moreover, there was no direct contact between the Geuzen and the Turkish authorities. The Turks were considered infidels, and the heresy of Islam alone disqualified them from assuming a more central (or consistent) role in the rebels' propaganda.

Geuzen (; French: Les Gueux, English: the Beggars) was a name assumed by the confederacy of Calvinist Dutch nobles, who from 1566 opposed Spanish rule in the Netherlands. The most successful group of them operated at sea, and so were called Watergeuzen (; French: "Gueux de mer", English: Sea Beggars). In the Eighty Years' War, the Capture of Brielle by the Watergeuzen in 1572 provided the first foothold on land for the rebels, who would conquer the northern Netherlands and establish an independent Dutch Republic. They can be considered either as privateers or pirates, depending on the circumstances or motivations.

丐军(,荷兰语发音:;,英语:the Beggars)是自1566年起反抗西班牙在尼德兰地区统治的荷兰贵族加尔文教徒及其他不满者组成的联盟。海上丐军(,荷兰语发音:;,英语:Sea Beggars)是他们当中行动最为成功的团体。在八十年战争期间,海上丐军于1572年占据布里勒,为立志征服尼德兰北部并建立独立的荷兰共和国的叛军提供了第一个立足点。视乎情况或动机,他们可被认为是武装商船或海盗。