F-Centres in Metaphosphate Glass
A NUMBER of investigators1 have shown that glass on exposure to radioactive and X-radiation becomes coloured. Sheline, Sharp and Arner2 suggested that this may be due to F-centres similar to those produced in alkali halides when bombarded by X-rays and cathode rays. Yokota3 found that F-centres could be created in fused silica and α-quartz by X-irradiation. He further showed that alkali silicate and borate glasses become coloured on X-irradiation due to formation of F-centres4. Przibram5 showed that F-centres could also be created in borate glass by β- and γ-irradiation from radium.
Verfärbung und Lumineszenz durch Becquerelstrahlen V nebst verwandten Erscheinungen
ZusammenfassungIn früheren Jahren hat der Verfasser von Zeit zu Zeit in dieser Zeitschrift zusammenfassend über seine und seiner Mitarbeiter Untersuchungen über Verfärbung und Lumineszenz, insbesondere durchBecquerel-Strahlen, berichtet. Dies soll hiermit nach einer längeren, durch die Zeitereignisse bedingten Pause wieder geschehen.
Numerical Simulation of Induction Heating Process of Continuous Casting Slab
Compared with traditional blazing furnace, the Continuous Casting-Direct Rolling is an advanced manufacturing steel technology, which can reduce energy waste, decrease pollution and enhance efficiency. The characteristics of steels during induction heating are complex, the change of material properties with temperature makes exact analysis methods very difficult to implement. Therefore, a powerful computer aided numerical tool (i.e., finite difference analysis) is selected to numerically model the induction heating process in this paper. The mathematic model coupling with electromagnetic field and thermal field was established, and it was solved by finite difference method (FDM), thus the slab temperature distribution and its variation with time were obtained, and the characteristics in whole induction heating process were studied. To validate the program feasible, the results were evaluated and compared with experiment results, which showed that the simulation results are reliable and effective. The skin effect in heating process from the two results was studied and demonstrated, the temperature change caused by different parameters such as the induced power intensity and the corner radian were also presented, which indicate that the slab temperature can be heated uniformly through adjusting these parameters, thus the continuous casting slab can meet the rolling requirement.