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<正>The microscopic defects have been investigated for crystal Tm3+/Yb3+:YVO4. These defects mainly include the inclusions (solid inclusions, bubbles and inclusions of the liquid phase), dendrites and growth stripes. They are caused by in-pure raw materials, unstable growth conditions, super-cooling component and so on. Tm3+/Yb3+:YVO4 crystals of large size and excellent optical quality are grown by improving the growth conditions to eliminate these defects.  相似文献   

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Poly(viyl chloride)/Na^ -montmorillonite(PVC/MMT)nanocomposites with different MMT contents were prepared via melt blending.Wide-angle X-ray diffraction(WAXD)and transmission electron microscopy(TEM)were used to characterize the structures.Effects of MMT content on the mechanical properties were also studied.It is found that PVC molecular chains can intercalate into the gallery of MMT layers during melt blending process,the stiffiness and toughness of the composites are inproved simultaneously within 0.5-7wt% MMT content,and the transparency and mechanical properties decrease as MMT conten further increases.  相似文献   

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Li^+/MgO上乙烷氧化脱氢的活性中心(Li^+O^—)的研究   总被引:1,自引:0,他引:1  
利用Li^+/MgO催化剂上乙烷氧化脱氢制乙烯及IR,TPD等测试手段对(Li^+O^-)中心的形成机理及其性质进行了研究,表明(Li^+O^-)中心最初生成与MgO表面的自由羟基相关,气相氧,反应温度,配位数等对生成(Li^+O^-)有一定程度的影响。  相似文献   

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采用等温溶解平衡法测定了四元交互体系Li~+,K~+/Cl~-,75℃的溶解度和平衡溶液的物化性质(密度、粘度、折光率).该四元交互体系50,75℃的溶解度等温图有5个相区:即Li_2SO_4·H_2O,KLiSO_4,KCl,K_2SO_4,LiCl·H_2O,7条单变量曲线,3个共饱点,其中Li_2O_4·H)2O+KCl+LiCl·H_2O为一致零变量点。用我们以往提出的经验公式处理了平衡溶液的密度和折光率,由所测得的溶解度数据,求得了高温和高锂浓度下的电解质溶液Pitzer模型的离子相互作用参数。计算了各平衡溶液中盐的活度和水的活度。还计算了该四元交互体系25℃的溶解度,考察了Pitzer电解质溶液理论在水-盐溶解度计算中的应用。  相似文献   

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四元交互体系Li^+,k^+/Cl,SO^2—4—H2O50,75℃相平衡研究   总被引:2,自引:0,他引:2  
采用等温溶解平衡法测了四元交互体系Li^+,K^+/Cl,SO^2-4-H2O50,75℃平衡溶液的物化物质(密度,粘度,折光率),该四元交互体系50,75℃的溶解度等温图有5个相区:即Li2SO4.H2O,KLiSO4,kcl,k2so4,lIcL.H2O,7条单变量曲线,3个共饱点,其中LiSO4.H2O+KCL+LiCl.H2O为一致零变量点,用我们以往提出的经验公式处理了平衡溶液的密度和折  相似文献   

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本文利用4-(1'-四氢吡咯)吡啶(PPY)及聚乙烯吡啶(PVP)复合催化剂催化合成了11,2',4'-三-0酰化红霉素衍生物,与传统方法相比,该法具有简单、快速、收率高等优点。一些影响素及反应机理被讨论,目标物收率为90%以上。  相似文献   

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研究了波长、温度及表面处理对n-InP光脉冲暂态行为的影响。结果表明,波长对时间常数无影响;随着温度升高,峰值下降,衰减变快。讨论了表面处理的影响,并对实验结果作了必要的解释。  相似文献   

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采用等温溶解平衡法研究了288K时Mg^2+,K^+//Cl^-,B4O7^2--H2O四元体系的相平衡关系,测定该体系在288K时平衡液相的溶解度和密度.依据实验测定的平衡溶解度数据及对应的平衡固相,绘制了该四元体系的平衡相图以及其密度一组成图.研究结果表明,四元体系Mg^2+,K^+//Cl^-,B4O7^2--H2O288K时的固液相平衡实验中,有复盐KCl&#183;MgCl2&#183;6H2O生成,平衡相图中有3个共饱点,7条单变量曲线,5个结晶区,对应的平衡固相分别为MgB4O7&#183;9H2O,K2B4O7&#183;4H2O,KCl,MgCl2&#183;6H2O,KCl&#183;MgCl2&#183;6H2O.简要讨论了实验结果.  相似文献   

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Zabuye Saline Lake, Tibet, China, is unrivalled in the world for its very high salinity, in particular, for the very high concentration of ions of lithium, potassium, and boron in the brine. It belongs to alkaline and carbonate-borate-type salt lake. As a part of the study on phase equilibrium of the 6component subsystem Li+, Na+, K+/C1-, CO2-3, B4O2-7-H2O of the brine system, a study on the reciprocal quaternary system Li+, K+/C1-, CO32-H2O at 298 K was done with isothermal dissolution equilibrium method in the present work. The phase equilibrium of the reciprocal quaternary system Li+,K+/C1, CO2-3-H2O at 298 K was studied with isothermal dissolution method in this work. The physicochemistry properties of the corresponding equilibrium solutions such as densities, viscosities, refractive index, conductivities and pH value were determined. The dried salt diagram of the system consists of four crystallization fields (KC1, Li2CO3, LiCI·H2O, K2CO3·3/2H2O) and five isothermal solubility curves.There are no double slat or solid solution found. Pitzer′s model of the electrolyte solution theory was used for parameterization from the results of solubility determination for subsystems and the prediction of solubilities for the reciprocal quaternary system was made. The solubility data of the experiment are in agreement with those calculated.  相似文献   

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本文采用等温溶解平衡法研究了四元交互体系Li+,Mg2+/CI-,SO-H2O25℃的机关系和平衡液相的物化性质(密度、粘度、电导率、折光率和pH).该体系25℃有七个相区Li2SO4·H2O,MgSO4·7H2O.MgSO4·6H2O.MgSO4·5H2O,MgC12,6H2O,LiCI.MgCl2.7H2O,LiCI·H2O,十一条单变量线,五个共饱点.其中LiCI·H2O+LiCI·MgCl2·7H2O+Li2SO4·H2O为一致零变量点.与文献中的研究结果比较,我们得到两个新相区MgSO4·6H2O和MgSO4·5H2O.用经验和半经验公式计算了平衡液相的密度、折光率.由实验测定的溶解度数据求得了高锂浓度下的Pitzer参数.对该体系25℃溶解度进行了理论计算复证.  相似文献   

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Ni^2+—胆红素和Ni^2+—2,2‘联吡啶—胆红素...   总被引:1,自引:0,他引:1  
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Introduction Na+/K+-ATPase (ATP phosphohydrolase, EC 3.6.1.3) is an important membrane-bound enzyme. It catalyzes the hydrolysis of ATP, and uses the energy from the reaction to maintain the low internal sodium and high internal potassium concentrations characteristic of most animal cells. So it has been convincingly identified with the sodium pump. The kinetics of Na+/K+-ATPase has been extensively researched by classical methods such as spectrophotometry, 32-ATP isotopic determinatio…  相似文献   

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Cu—Fe—Ce—O/γ— Al2O3催化CO+NO反应的TP—FT—IR研究   总被引:2,自引:0,他引:2  
运用TP-FT-IR技术研究了CO、NO、NO+CO在负载型Cu-Fe-Ce-O(Ⅰ)和Cu-Fe-O(Ⅱ)催化剂上的吸附行为。研究表明,NO具有比CO更强的吸附能力,可与表面氧反应生成硝基、亚硝酸盐、硝酸盐等物种。在NO+CO反应过程中,在催化剂表面存在(CO.NO)*表面络合物(2400-2430cm^-1)和NCO*(异氰酸盐)表面物种,其关系为:CO*+NO*→(CO.NO)*+*→NCO  相似文献   

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通过X射线光电子能谱和低能电子衍射实验研究了10~180 eV的Ar+、 He+、S+离子轰击n-InP(100)表面, 发现S+离子轰击可以产生In-S组分,减轻离子轰击对表面的物理损伤.对于Ar+离子轰击后的表面,经过S+离子处理和加热过程以后,表面损伤得到了修复,最终得到了2×2的InP表面,进一步验证了S+离子对InP表面的修复作用.  相似文献   

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