The research of high-quality grinding technology of large-size Al2O3 single-crystal slice
Al<inf>2</inf>O<inf>3</inf> single crystal has the following unique physical properties of high hardness, high toughness, obvious pleochroism and high refractive index Etc. The paper introduced the processing property of Al<inf>2</inf>O<inf>3</inf> single crystal, described its grinding technology. Then analyzed the characteristics and status of grinding technology of the large-sized Al<inf>2</inf>O<inf>3</inf> single crystal, combined with the relational research, discussed the technology of the grinding stage. Finally the paper summarized a set of precise grinding technology of large-sized Al<inf>2</inf>O<inf>3</inf> slice.
A new approach for the characterization of machinability—application to steels for plastic injection molds
Abstract An economical analysis of the plastic injection market highlights the necessity to increase productivity. Mold steel influences the total cost of an injected part more through its capability to be worked than through its own price. Among the mold manufacturing operations, rough and finish machining are two of the most expensive, depending strongly upon the mold steel machinability. A new method has been developed to compare the machinability of three 300 HB mold steels during rough milling. Based on a half-fractional design of experiments, a new model is proposed which takes into account material variation, as well as cutting parameter interactions. The application of this approach has shown the interest of a new redesigned grade presenting high surface properties, which could be as machinable as a high sulfur content grade which presents limited surface finishing capabilities.
Antitumor activities of (2"R)-4'-O-tetrahydropyranyl-adriamycin (THP) and its combination with other antitumor agents on murine tumors.
(2''R)-4'-O-Tetrahydropyranyladriamycin (THP) is a new derivative of doxorubicin (adriamycin, ADM). The concentrations of THP and ADM required to inhibit by 50% the growth of a cultured L1210 cells was 0.003 microgram/ml and 0.016 microgram/ml, respectively. Various therapeutic designs of combinations of THP with other antitumor agents were investigated in vivo using the L1210 murine leukemia. The combination of THP with cytosine arabinoside (Ara-C), cyclocytidine hydrochloride (Cyclo-C), 6-mercaptopurine (6-MP) and cyclophosphamide (EX) showed a great effectiveness following daily intraperitoneal treatment from days 1 to 10. High therapeutic effects were also obtained with the combinations of THP with Ara-C, Cyclo-C, vincristine (VCR) and EX following intravenous combination therapy one day following implantation of L1210 leukemia. Schedule dependency and its therapeutic efficacy of THP were examined. THP showed almost the same antitumor activity on the solid-type sarcoma-180 or solid-type Ehrlich carcinoma as ADM by intraperitoneal or intravenous treatment. THP showed some superior activity to ADM in the advanced stage of L1210 leukemia. High antitumor activity of THP on murine leukemia L1210 has been reported by Tsuruo et al. (Cancer Res. 42: 1462-1467, 1982) and was also confirmed. THP gave many mice cures, especially in the intravenous treatment.