透明陶瓷的研究进展

综述了透明的陶瓷的优点,对影响陶瓷透明度的制备因素、本征因素进行了说明,并对本征因素进行了简要分析.分别介绍了氧化物透明陶瓷和非氧化物透明陶瓷的性质、应用以及研究现状,重点说明了激光陶瓷Nd:YAG和闪烁陶瓷的研究进展.此外,对透明陶瓷未来的发展趋势进行了展望.     

透明陶瓷的研究现状与发展展望

简要地论述了国内外对透明陶瓷的研究现状，重点介绍了透明陶瓷制备中出现的新方法和新工艺，探讨了气孔和晶界组织结构等因素对透明陶瓷的透光性能的影响，并对透明陶瓷研究的发展提出了自己的看法。     

激光陶瓷的研究进展

随着透明陶瓷制备技术的不断发展,使得部分透明陶瓷成功用作激光放大介质,这为透明陶瓷的应用开辟了新的领域,即用作激光陶瓷.本文对激光陶瓷的研究现状和发展作了综合评述.     

热等静压技术在透明陶瓷研究中的应用进展

透明陶瓷具有与单晶材料相媲美的光学、力学和热学等性能，被广泛应用在透明装甲、红外窗口、高功率激光器、白光照明、医学诊疗等民用和军事领域。影响透明陶瓷光学透过率的主要因素是气孔，而热等静压（HIP）后处理是消除气孔，获得高质量透明陶瓷的有效办法之一。本文综述了近期利用热等静压技术研究透明陶瓷取得的成果和提出的一些机理，进而对热等静压技术开发透明陶瓷进行了讨论和展望。     

问：透明陶瓷有哪些用途？请介绍一下制备工艺及性能。

答：一般陶瓷是不透明的，但是光学陶瓷像玻璃一样透明，故称透明陶瓷。普通陶瓷不透明的原因是其内部存在杂质和气孔，前者能吸收光，后者令光产生散射，所以就不透明了。因此如果选用高纯原料，并通过工艺手段排除气孔就可以获得透明陶瓷。     

微波辅助沉淀法荧光粉体的制备及其用于白光LED的研究

本项目拟采用微波辅助共沉淀法制备Ce:YAG荧光粉体,接着通过高温真空烧结得到了Ce:YAG透明陶瓷。利用透明荧光陶瓷进行LED封装,使其在蓝光LED芯片照射下产生白光,实现"蓝光芯片+Ce:YAG透明荧光陶瓷"发光和外壳一体化。通过XRD、SEM等手段对粉体和陶瓷进行了表征和研究,优化纳米粉体制备条件和陶瓷烧结工艺,制备性能优良的透明荧光陶瓷。     

透明玻璃陶瓷

透明玻璃陶瓷是由细晶粒和玻璃相组成的具有均匀致密结构的新型功能材料。本文综述了透明玻璃陶瓷的制备工艺、种类及性能,并对透明玻璃陶瓷的发展作了展望。     

光固化3D打印钇铝石榴石透明陶瓷及其微结构调控

成型是钇铝石榴石(YAG)透明陶瓷研制的关键环节,对透明陶瓷的致密化过程及其力学、热学和光学性能有重要影响。本工作围绕YAG透明陶瓷的基于数字光处理(DLP)技术的光固化3D打印成型,系统地开展了YAG陶瓷浆料的研制、陶瓷生坯的构筑及坯体脱脂和烧结工艺研究。采用流变仪分析了固含量对陶瓷浆料流变特性的影响,借助分析曝光参数对单层陶瓷膜特性的影响,确立了最佳的光固化工艺参数。结合TG–DTA分析,对陶瓷坯体脱脂制度进行了精准控制。采用真空高温烧结工艺制备得到高致密YAG透明陶瓷,讨论了固含量、烧结温度等工艺参数对YAG透明陶瓷微结构演变及光学质量的影响,基于DLP光固化成型技术成功制备出可见光透过率高达82.9%的高性能YAG透明陶瓷。     

读者信箱

问：透明陶瓷的应用领域有哪些？其研究进展和发展现状如何？ 答：1简介 一般陶瓷是不透明的，但是光学陶瓷或钠灯灯管等制品像玻璃一样透明，故称透明陶瓷。一般陶瓷不透明的原因是其内部存在杂质和气孔，前者能吸收光，后者令光产生散射，所以就变得不透明。如果选用高纯原料，并通过一定的工艺方法排除气孔就可能获得透明陶瓷。早期就是采用此方法得到透明的氧化铝陶瓷，后来研究出如烧结白刚玉、氧化镁、氧化铍、氧化钇、氧化钇一二氧化锆等多种氧化物系列透明陶瓷。近期又研制出非氧化物透明陶瓷，如砷化镓、硫化锌、硒化锌、氟化镁、氟化钙等。     

透明陶瓷的制备技术及其透光因素的研究

简要地介绍了国内外透明陶瓷的制备技术,同时探讨了气孔和晶界组织结构等因素对透明陶瓷的透光性能的影响,并展望了透明陶瓷研究的发展趋势.     

武器信息化条件下火炸药发展策略分析

分析了火炸药与武器信息化的关联性;论述了火炸药在武器装备发展中的综合地位与作用;提出作为武器信息化条件下火炸药发展策略和基本点的六项技术,即火炸药相关信息量的整合与准确表达、高能量与高安全性的统一、能量释放的可控制性、洁净燃烧与爆炸技术、燃烧爆炸的物理与化学作用延伸、非致命武器与化学战剂等.     

果蓬类原料致密成型特征及其机制炭质量分析

以山核桃、油茶和板栗3类果蓬为原料,研究了此类原料与杉木、松木屑在不同配比条件下对果蓬类致密成型特征及其机制炭质量的影响。证实了果蓬类原料因纤维素含量、木质素含量与杉木、松木存在差异,且因较高的灰分含量限制,需与杉木或松木屑等原料在一定配比条件下才可实现良好的致密成型。而配比选择试验结果则表明,果蓬原料与杉木、松木屑混合原料以3:7比例配料为宜;在此条件下,制备的机制炭外形平直无裂缝,得率为 33.85%~36.73%,固定碳含量 79.80%~86.20%,热值28.96~31.92 MJ/kg。     

On Porosity of Carbon Aerogels from Sol-Gel Polymerization of Phenolic Novolak and Furfural

Carbon aerogels were prepared by sol-gel polymerization of phenolic novolak and furfural followed by supercritical drying and pyrolysis. The porosity and morphologies of carbon aerogels were characterized by nitrogen adsorption, apparent density, He- pycnometer method, and transmission electronic microscopy (TEM). Effect of ratios of phenolic novolak to furfural (Ra) and total concentration of reactants (C) in sol-gel step on porosity and morphologies of carbon aerogels was investigated. The carbon aerogels synthesized are rich in meso- and macropores. The Ra determines the cross-linking density of polymers, thereby the compatibility of the polymers, and ultimately the shrinkage of gels in the drying and pyrolysis. The network sizes and the porosity of organic and carbon aerogels are mainly determined by Ra. The C has no effect on volume shrinkage of gels in drying and pyrolysis and has only dilute effect in determining bulk density of organic and carbon aerogels, and ultimately the porosity of carbon aerogels. Conversion of mesopores to micro- and macropores is observed, which is related to combination of C and Ra, and determines the partition of micro-, meso- and macropores.     

Fifty years with bile acids and steroids in health and disease

Cholesterol and its metabolites, e.g., steroid hormones and bile acids, constitute a class of compounds of great biological importance. Their chemistry, biochemistry, and regulation in the body have been intensely studied for more than two centuries. The author has studied aspects of the biochemistry and clinical chemistry of steroids and bile acids for more than 50 years, and this paper, which is an extended version of the Schroepfer Medal Award lecture, reviews and discusses part of this work. Development and application of analytical methods based on chromatography and mass spectrometry (MS) have been a central part of many projects, aiming at detailed characterization and quantification of metabolic profiles of steroids and bile acids under different conditions. In present terminology, much of the work may be termed steroidomics and cholanoidomics. Topics discussed are bile acids in human bile and feces, bile acid production, bacterial dehydroxylation of bile acids and steroids during the enterohepatic circulation, profiles of steroid sulfates in plasma of humans and other primates, development of neutral and ion-exchanging lipophilic derivatives of Sephadex for sample preparation and group separation of steroid and bile acid conjugates, profiles of steroids and bile acids in human urine under different conditions, hydroxylation of bile acids in liver disease, effects of alcohol-induced redox changes on steroid synthesis and metabolism, alcohol-induced changes of bile acid biosynthesis, compartmentation of bile acid synthesis studied with 3H-labeled ethanol, formation and metabolism of sulfated metabolites of progesterone in human pregnancy, abnormal patterns of these in patients with intrahepatic cholestasis of pregnancy corrected by ursodeoxycholic acid, inherited and acquired defects of bile acid biosynthesis and their treatment, conjugation of bile acids and steroids with N-acetylglucosamine, sulfate-glucuronide double conjugates of hydroxycholesterols, extrahepatic 7alpha-hydroxylation and 3-dehydrogenation of hydroxycholesterols, and extrahepatic formation of C27 bile acids. The final part discusses analysis of free and sulfated steroids in brain tissue by capillary liquid chromatography-electrospray MS and suggests a need for reevaluation of the function of steroid sulfates in rat brain.     

己烷油装置储运系统增上油气回收系统的可行性分析

简述了己烷油装置配套的储运系统现状,综述了低温冷凝法、活性炭吸附法、溶解吸收法、膜选择渗透法以及氧化燃烧法五种油气回收技术的原理,评价对比其中四种技术的尾气排放情况、二次污染情况、安全运行状态、设备工艺复杂程度等指标,根据各单一技术的优缺点,探讨了冷凝法和吸附法相结合、冷凝法和膜分离法相结合的两种较为实用的油气回收复迭技术,简述了其工作原理。对己烷油装置的储运系统提出改进建议,得出增上油气回收系统的可行性结论。     

从化学组成上区分宋代汝瓷与民窑钧瓷

应用质子激发Ｘ荧光分析技术测定了一组宋代汝瓷和一组宋代民窑钧瓷瓷片的化学组成及浓度，对汝瓷与民窑钧瓷的主量，次量化学组成和痕量化学组成进行了比较，应用模式识别方法加以研究，得到了区分宋代汝瓷和民窑钧瓷的可视分类图和数学判据。     

纳米阻燃抑烟PVC的研究进展

PVC是一种应用广泛的高分子材料,但因其具有热稳定性差、易燃烧、发烟量大的缺点而限制了发展,因此PVC的阻燃与抑烟成为阻燃科学研究领域的关键问题之一。纳米型阻燃抑烟剂克服了传统型阻燃抑烟剂添加量大、阻燃抑烟效果不明显的缺点,为研究和解决PVC阻燃抑烟提供了一个新途径。本文介绍了PVC纳米阻燃抑烟剂的制备方法、表征手段及其在PVC中的应用以及PVC降解、阻燃与抑烟的表征,最后简要论述PVC阻燃抑烟的发展趋势。     

世界油气主产国油气资源管理的基本经验及启示

油气是重要的战略资源,关系国计民生。随着工业化和城镇化的加速推进以及汽车进入普及期,我国油气供需形势日趋严峻。解决我国油气供应不足的问题。应首先立足于开发利用国内的油气资源,不断提高自给水平,然而却存在管理体制和政策的掣肘。世界油气主产国都不断改善其油气资源开发利用的管理体制与政策,促进更加有效与合理地开发利用和保护油气资源。本文总结了该领域的国际经验,从加强油气资源法律法规体系建设、促进油气资源管理体制改革、完善油气资源矿业管理等方面提出了对我国的启示和改革建议。     

Glyceride isomerizations in lipid chemistry

Isomerization of isopropylidene glycerol ketals and benzylidene glycerol acetals was studied, and isoraerization equilibria were established. Reaction of benzaldehyde with glycerol gave four benzylidene glycerol isomers, which were separated by column chromatography and characterized by NMR spectroscopy and other methods. Isomerization of 1- and 2-monoglycerides and of 1,2- and 1,3-diglycerides, and their separation by column chromatography, are described. Mechanisms of isomerization in mono- and diglycerides and factors which affect them are discussed. Isomerization of 1- and 2-glycerophosphates and of cyclic glycerophosphates by acid and base was also studied. Hydrolysis products of L-3-glycerylphosphorylcholine and 2-glycerylphosphorylcholine were separated by column chromatography and characterized by periodic acid oxidation, optical rotation, and NMR spectroscopy. No isomerization of unhydrolyzed L-3-glycerylphosphorylcholine and 2-glycerylphosphorylcholine was observed. Evidence indicated that acid-catalyzed hydrolyses of phosphoglycerides are under thermodynamic control whereas most base-catalyzed hydrolyses are under kinetic control.     

Promising applications of coals from the Moscow Basin

The results of an analysis of the current state of the Moscow Coal Basin and the development of science and technology for the multiple use and conversion of coal into refined energy carriers, products, and materials with new consumer properties are presented. It is demonstrated that a number of processes and facilities based on the coals and overburden rocks of the basin have been prepared for technical implementation, namely: the generation of heat and power at plants with in-cycle coal gasification; the fluidized-bed combustion of coal in low-power boiler units (50?C60 MW); the manufacture of ballast-free humic plant growth stimulators and coagulants for the purification of wastewater and drinking water; and the use of coals and coal mining and benefication wastes as catalytic additives in the process of hydrogenation.