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Chunling Liu Yanping Yao Chunwu Wang Xin Gao Zhongliang Qiao Mei Li Yuxia Wang Baoxue Bo 《中国光学快报(英文版)》2008,6(3)
In order to improve the optical properties of the Ⅲ-Ⅴ laser diodes(LDs) by means of H2S plasma passivation technology,H2S plasma passivation treatment is performed on the GaAs(110) surface.The optimum passivation conditions obtained are 60-W radio frequency(RF)power and 20-min duration.So the laser cavity surfaces axe treated under the optimum passivation conditions.Consequently,compared with unpassivated lasers with only AR/HR-coatings,the catastrophic optical damage (COD) threshold value of the passivated lasers by H2S plasma treatment is increased by 33%,which is almost the same as that of (NH4)2Sx treatment.And the life-test experiment has demonstrated that this passivation method is more stable than(NH4)2Sx solution wet-passivated treatment. 相似文献
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Ferritic/martensitic (F/M) steels are good candidate structural materials for the future fusion reactors and spallation sources. However, irradiation of steels is known to produce hardening, loss of ductility, shift in ductile to brittle transition temperature (DBTT) and reduction of fracture toughness and creep resistance starting at low doses. Helium (He), produced by transmutation during the irradiation, also impacts mechanical properties. Numerous experimental and theoretical studies on the evolution of the microstructure of steels under irradiation have been conducted until now. We review the effect of irradiation-induced point defects and in particular of He on the mechanical properties of F/M steels. To cite this article: R. Schäublin et al., C. R. Physique 9 (2008). 相似文献
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The damage spreading of the Ising model on three kinds of networks is studied with Glauber dynamics. One of the networks is
generated by evolving the hexagonal lattice with the star-triangle transformation. Another kind of network is constructed
by connecting the midpoints of the edges of the topological hexagonal lattice. With the evolution of these structures, damage
spreading transition temperature increases and a general explanation for this phenomenon is presented from the view of the
network. The relationship between the transition temperature and the network measure-clustering coefficient is set up and
it is shown that the increase of damage spreading transition temperature is the result of more and more clustering of the
network. We construct the third kind of network-random graphs with Poisson degree distributions by changing the average degree
of the network. We show that the increase in the average degree is equivalent to the clustering of nodes and this leads to
the increase in damage spreading transition temperature.
相似文献
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William H. Massover 《Journal of synchrotron radiation》2007,14(1):116-127
Recent research progress using X‐ray cryo‐crystallography with the photon beams from third‐generation synchrotron sources has resulted in recognition that this intense radiation commonly damages protein samples even when they are held at 100 K. Other structural biologists examining thin protein crystals or single particle specimens encounter similar radiation damage problems during electron diffraction and imaging, but have developed some effective countermeasures. The aim of this concise review is to examine whether analogous approaches can be utilized to alleviate the X‐ray radiation damage problem in synchrotron macromolecular crystallography. The critical discussion of this question is preceded by presentation of background material on modern technical procedures with electron beam instruments using 300–400 kV accelerating voltage, low‐dose exposures for data recording, and protection of protein specimens by cryogenic cooling; these practical approaches to dealing with electron radiation damage currently permit best resolution levels of 6 Å (0.6 nm) for single particle specimens, and of 1.9 Å for two‐dimensional membrane protein crystals. Final determination of the potential effectiveness and practical value of using such new or unconventional ideas will necessitate showing, by experimental testing, that these produce significantly improved protection of three‐dimensional protein crystals during synchrotron X‐ray diffraction. 相似文献
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Demetre J. Economou 《Applied Surface Science》2007,253(16):6672-6680
Ion-ion plasmas can form in the late afterglow of pulsed discharges or downstream of continuous wave discharges in electronegative gases. In ion-ion plasmas, negative ions replace electrons as the negative charge carriers. In the absence of electrons, ion-ion plasmas behave quite differently compared to conventional electron-ion plasmas. Application of a radio frequency bias to a substrate immersed in an ion-ion plasma can be used to extract alternately positive and negative ions, thereby minimizing charging on device features during micro-device fabrication. Ion-ion plasmas are also important in negative ion sources, dusty plasmas, and the D-layer of the earth's atmosphere. 相似文献