LaK747/509光学玻璃的改进

本文着重研究了B₂O₃—La₂O₃—ZnO与B₂O₃—La₂O₃—CdO为基础的多元系统LaK747/509玻璃性能之间的差异,试验了向玻璃中引入氟化铝对玻璃性质的影响,最后在B₂O₃—La₂O₃—ZnO多元系统中,研制成功了无钍、无镉、无钇的LaK₃改进配方。玻璃的光吸收得到了显著改善,去掉了毒害较重的CdO原料,大大降低了生产成本。为LaK₃玻璃的扩大生产及广泛应用,提供了基础及有利条件。     

B2O3—La2O3—BaO—Nb2O5系统的玻璃生成范围及其性质

本文研究了在B₂O₃-La₂O₃-BaO-Nb₂O₅四元系统中当B₂O₃含量分别为25、30、35wt%时,该系统的玻璃生成范围和它们的光性、密度等变化规律。结果表明,随着B₂O₃含量的增加,系统的玻璃生成范围向贫Nb₂O₅边界扩充,富Nb₂O₅边表现收缩。工作中得出了该系统分别以SiO₂代B₂O₃、Al₂O₃代BaO后的析晶、折射率、色散及密度等性质的变化规律。最后应用该系统研制定型了713/538玻璃。     

Na2O-B2O3-Ta2O5系统玻璃红外光谱的研究

本文首次系统地研究了Na₂O—B₂O₃—Ta₂O₅。三元新系统的红外光谱,分析了B₂O₃、Ta₂O₅含量的变化对玻璃结构的影响。结果表明:随着Na₂O/B₂O₃比值的减小,结构中:[BO₄]四面体减小,[BO₃]三角体增加。随着Ta₂O₅含量的增加,[BO₄]四面体的数量增多,非桥氧的数量减少,表明Ta⁵⁺可以连结非桥氧,形成网络。     

铝氟磷酸盐系统玻璃的研究

本工作首次由实验获得了R₁(PO₃)₂-AlF₂-R₂F₂(R₁:Mg、Sr;R₂:Zn、Cd、Pb)和Mg(H₂PO₄)₂-AlF₃-ZnF₂等7个新的相图。利用FT-IR、Raman、XRD、DTA、ESCA等技术首次研究了其中的Mg(PO₃)₂-AlF₃-PbF₂系统的性质与结构及晶化机理。建立了本系统玻璃的结构模型。推导出了新的计算活化能和Avrami指数的公式。     

SiO2-BaO-La2O3-RmOn系统玻璃的光吸收

本文系统地研究了,SiO₂-BaO-La₂O₃-R_mO_n系统玻璃的光吸收。通过选用不同硅硼比值及引入适宜的Nb₂O₅含量获得了紫外区透过率好,抗析晶性能好的玻璃。     

稀土光学玻璃着色的研究

本文系统地测定了第一过渡金属(Fe,Co,Ni,Cu,Cr,Mn 等)离子和稀土(Ce,Pr,Nd,Sm 等)着色离子在 B₂O₃-BaO,B₂O₃-La₂O₃-BaO,B₂O₃-BaO-SiO₂,B₂O₃-BaO-SiO₂-La₂O₃及氟磷等系统玻璃中的吸收光谱。比较了各种着色离子对不同系统玻璃的着色情况。阐述了3d 轨道部分填充的过渡金属离子及具有4f 壳层受5s,5p 电子层屏蔽的 Ce,Pr,Nd,Sm 离子在玻璃中的着色机理。并讨论了玻璃生成体B^a+,si⁴⁺,P⁵⁺阳离子及网络外体离子 La³⁺,F^-对玻璃着色的影响。最后提出了稀土玻璃中稀土杂质含量的允许值。     

Ta2O5对B2O3-La2O3-CaO系统玻璃生成范围的影响

本文研究了在B₂O₃—La₂O—CaO三元系统中,当Ta₂0₅的含量分别为5、10、15、20wt%时,该系统的玻璃生成范围.结果表明,随着Ta₂O₅含量的增加,系统的玻璃生成范围向贫B₂O₃,富La₂O₃边界扩充.当Ta₂O₅的含量为10wt%时,玻璃的生成区域最大.通过差热分析确定了玻璃析晶温度,并用X射线衍射进行了物相鉴定.结果表明,随Ta₂O₅取代La₂₃其主结晶相的放热峰或吸热峰的位置变化不同,所析出的结晶物质亦不同.     

X2O3(X=B、Al、Ga)-K2O(ZnO)-Nb2O5系统玻璃生成及性质

用通常的玻璃熔融浇注或高温水淬火方法,研究了(B、Al、Ga)₂O₃-K₂O(ZnO)一Nb₂O₅系统玻璃生成能力。测定了有关玻璃的折射率、色散、密度及红外透过率等性质。实验结果表明:钾铌酸盐K(NbO₃)比锌铌酸盐Zn₂(Nb₂O₇)易形成玻璃;X₂O₃-K₂O-Nb₂O₅各系统均能形成玻璃。值得注意的是,X₂O₃含量低于30%mol(甚至可低达10%mol)时,仍然能生成玻璃。这时,Nb₂O₅含量按B³⁺、Al³⁺、Ga³⁺顺序而趋向增加(25-45%mol)。其中Al₂O₂和Ga₂O₃钾铌酸盐玻璃红外透过截止波长大于6μm;Nb₂O₅-B₂O₃-K₂O系统玻璃具有高色散、低折射率等性质,它们的密度与光性相近的其它玻璃相比又比较小。最后,根据玻璃结构参数、键参数、电负性与平均离子半径比的关系等计算结果,推断了Nb⁵⁺的配位数为四和六。Nb₂O₅在Nb₂O₅-X₂O₃-K₂O系统中赋存状态为偏铌酸盐。     

铌硼酸盐玻璃熔体的高温红外光谱

本文首次采用高温红外光谱及DSC—7差热分析技术研究了Nb₂O₅—B₂O₃—K₂O系统玻璃熔体结构,并建立了该系统玻璃和高温熔体结构模型。     

用于硅太阳能电池的高效减反射膜

文中论述了硅电池上各类减反膜的特性。分析了λ₀/4和非λ₀/4膜厚的双层减反膜;介绍了TiO₂—SiO₂和TiO₂—Al₂O双层减反膜的设计、工艺和实验结果的有关数据。结果表明,该膜层牢固、性能稳定,可使硅太阳能电池获得较高的光电转换效率。     

Book Reviews

Book reviewed in this article: Functional Histology. A Text and Atlas . By P. R. Wheater, H. G. Burkitt and V. G. Daniels. Electron Energy-Loss Spectroscopy in the Electron Microscope . By R. F. Egerton. Principles of Analytical Electron Microscopy . Edited by D. C. Joy, A. D. Romig, Jr & J. I. Goldstein. Basic Techniques for Transmission Electron Microscopy . By M. A. Hayat. RMS Handbooks. 11. An Introduction to Immunocytochemistry: Current Techniques and Problems. Revised Edition . By J. M. Polak and S. Van Noorden.     

Book Reviews

Book reviewed in this article: Cytodifferentiation in Plants—Xylogenesis as a Model System . By L. W. Roberts Freeze-fracture Replication of Biological Tissues. Techniques, Interpretation and Applications . By C. Stolinski and A. S. Breathnach Advances in Optical and Electron Microscopy . Vol. 6. Ed. R. Barer and V. E. Cosslett Ultrastruktur der Säugetierzelle . By R. V. Krstic Practical Scanning Electron Microscopy . Ed. by J. I. Goldstein and Harvey Yakowitz Practical Methods of Electron Microscopy, Vol. 3 . Part I—Fixation, dehydration and embedding of biological specimens. Part II—Ultramicrotomy. Ed. A. M. Glauert Defect Analysis in Electron Microscopy . By M. H. Loretto and R. E. Smallman Histochemical Techniques . 2nd edn. by J. D. Bancroft     

Book Reviews

Book reviewed in this article: The Science of Biological Specimen Preparation for Microscopy and Microanalysis . Edited by J. P. Revel , T. Barnard and G. M. Haggis . The Preparation of Biological Specimens for Scanning Electron Microscopy . Compiled by J. A. Murphy and G. M. Roomans . Computer-assisted Image Analysis Cytology . Edited by S. D. Greenberg . The Light Microscopy of Synthetic Polymers . By D. A. Hemsley . Journal de Physique, Colloque No. 2.     

Book Reviews

Book reviewed in this article: Stereology of Objects with Internal Structure. By Ivan Saxl. Microprobe Analysis in Medicine. Ultrastructure in Pathology Publication Series. Ed by P. Ingram, J. D. Shelburne, V. L. Roggli (Consulting Editors: J. V. Johannessen and V. E. Gould). R.M.S. Microscopy Handbook No. 18: Autoradiography: A Comprehensive Overview. By John R. J. Baker.     

Reviews

Book reviewed in this article: Practical Photomicrography . By J. Bergner , E. Gelbke , and W. MEhliss . English Edition translated by K. S. Ankersmit from the German Edition (Einführung in die praktische Mikrofotografie) Crystal Symmetry and Physical Properties . By S. BHAGAVANTAM. Rotifers . By Josef Donner . English translation by H. G. S. Wright . Modern Microscopy . By V. E. Cosslett .     

Book Reviews

Book reviewed in this article: Methods of Preparation for Electron Microscopy . By D. G. Robinson , U. Ehlers , R. Herken , B. Herrmann , F. Mayer and F.-W. Schürmann . The Physics of Medical Imaging . Edited by S. Webb . Adam Hilger     

Reviews

Book reviewed in this article: Electron Microscopy of Cells and Tissues . Volume 1, Instrumentation and Techniques . By Fritiof S. Sjöstrand. Cell Structure. An introduction to biological electron microscopy . By Peter G. Toner and Katharine E. Carr. Scanning Electron Microscopy—Applications to materials and device science . By P. R. Thornton. The Biochemistry of Animal Development , Vol II. Biochemical Control Mechanisms and Adaptations in Development . Edited by Rudolf Weber.     

An instrument for measuring thermal characteristics of metals and alloys

An all-soldered instrument capable of measuring the density, surface tension, electron work function for metals or alloys, and wetting of solid surfaces under high static vacuum conditions has been designed and tested. Measurements of thermal characteristics of lithium samples have demonstrated a high reliability of the instrument. Original Russian Text ? B.B. Alchagirov, L.Kh. Afaunova, F.F. Dyshekova, T.M. Taova, R.Kh. Arkhestov, A.G. Mozgovoi, Z.A. Kokov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 3, pp. 148–151.     

高压换热器的热处理

按设备制造规范和工程设计标准、图样要求，结合生产实际，制订出高压换热器球形封头热成形加热及热处理工艺、焊前进炉预热工艺、焊后热处理工艺、最终合拢缝局部焊后热处理工艺、最后做出经验总结，作为今后尿素高压设备热处理的参考。     

d.o.f. of equivalent conjugate motion between two bodies in a mechanical system

In modern mechanical systems, especially in robotics and bio-mechanics, there are needs to investigate higher pairs in more details, and to compute the d.o.f. of the relative motion between two bodies, rather than the d.o.f. of the whole system. In this paper, conjugate pairs are investigated with the aid of the theory of conjugate surfaces. This investigation provides a geometrical insight of the d.o.f. of a joint. The conjugation chain and the corresponding algorithm are introduced. They provide an instrumental tool for computing the d.o.f. of the equivalent conjugate motion between two bodies in a mechanical system. The existence of the redundant and the complementary d.o.f. is briefly explained.