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Zusammenfassung Bei röntgenographischen Untersuchungen im System GeO2-P2O5 wird eine Verbindung der Zusammensetzung 2 GeO2·P2O5 aufgefunden. Einkristallaufnahmen ergeben eine hexagonale (trigonale) Elementarzelle mita=7,998 undc=24,86 Å. Die schon beschriebene Verbindung 2 SiO2·P2O5 erweist sich als isotyp:a=7,862 undc=24,13 Å. 相似文献
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本文提出一种Gibbs-Dubem关系的变通形式。应用該式可以从已知的二元系中二个组元的活度系数之此,分别求出二个組元的活度。将該式应用于PbCl_2-SnCl_2及PbCl_2-CdCl_2系,証明这二熔盐体系对Raoult定律仅呈較小的正偏差。此外,对反应Sn+PbCl_2→Pb+SnCl_2和Cd+PbCl_2→Pb+CdCl_2的标准自由能变化(△F°)作了修正。 相似文献
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2MgO·2B2O3·MgCl2·14H2O-MgCl2-H2O体系30℃相平衡 总被引:2,自引:0,他引:2
用相平衡方法研究2MgO@2B2O3@MgCl2@14H2O在30℃不同质量分数MgCl2水溶液中的溶解转化产物及其溶解度.结果表明,该复盐在MgCl2的质量分数0~2%浓度范围,发生不同步溶解并转化为多水硼镁石(2MgO@3B2O3@15H2O);在MgCl2的质量分数2%~13.8%浓度范围,转化为柱硼镁石(MgO@B2O3@3H2O),这一结果比文献报导的该硼酸盐的形成温度低了13℃,为盐湖硼酸镁矿物柱硼镁石形成的解释提供了物理化学依据;而在MgCl2质量分数大于13.8%时,同步溶解,不发生转化.提出了溶解相转化反应机理. 相似文献
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《Journal of solid state chemistry》1986,61(2):263-268
The heat capacities of MnCl2·2H2O and MnCl2·2D2O have been experimentally determined from 1.4 to 300 K. The smooth heat capacity and the thermodynamic functions (H°T − H°0) and S°T are reported for the two compounds over the 10 and 300 K temperature range. The error in the thermodynamic functions at 10 K is estimated at 3%. Additional error in the tabulated values arising from the heat capacity data above 10 K is thought to be less than 1%. Lambda-shaped heat capacity features associated with antiferromagnetic ordering were observed at 6.67 ± 0.08 and 6.61 ± 0.08 K for the dihydrate and dideuterate, respectively. In addition, compound heat capacity anomalies consisting of a small lambda-shaped feature at 57.7 ± 0.5 K with a comparably large high-temperature shoulder extending to approximately 70 K were observed in both the dihydrate and dideuterate. The entropies associated with these anomalies are 0.42 ± 0.04 and 1.04 ± 0.04 J/mole-K, respectively. 相似文献
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P_2O_5-V_2O_5-TiO_2(简写为P-V-Ti)对芳烃氧化有良好的催化效果.丁烷氧化催化剂P-V体系的体相和表面结构已有一些报道.但P_2O_5对V-Ti的影响文献较少报道.本文用XRD,IR,TPD和ESR考察了P-V-Ti体系. 1.试剂和催化剂:草酸、偏钒酸铵、二氧化钛均为化学纯.将V_2O_5:TiO_2=11:89(重量)样品分别按 P/V原子比为0.1,0.3,0.6,1.0,1.5和2.5制成编号为P-0.1,P-0.3,P-O.6,P-1.0,P-1.5和P-2.5的催化剂. 相似文献
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关于过渡金属Pd,Pt对C_2H_2的吸附和氢化实验研究前人已作了不少工作,但有关Pd,Pt与C_2H_2之间成键问题的理论研究还尚不多见。为了了解Pd,Pt d轨道对炔键的活化行为和成键特性,本文以MC_2H_2(M=Pd,Pt)为模型,用赝势计算方法,对Pd,Pt与C_2H_2键的相互作用进行了研究。一、计算方法由于重原子的内层轨道对形成分子贡献很小,内层电子的相对论效应极为严重。本文采用Ps—HONDO程序,选取Hay的有效核芯势和价轨道Gaussian基组,对重原子Pd和Pt进行了价电子从头计算,对C和H进行了全电子从头算.部分地消除重原子内层电子相对论效应所引起的误差。 相似文献
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Crystal structure of the title complex was determined by X-ray diffraction method. It crystallizes in space group P21/n with cell dimensions:α=10. 041(5) , b=10. 719(4) , c= 1. 5671(6) nm, β=104. 36(3)°. The structure was solved by Patterson method. The final residual factor is R=0. 050. 相似文献
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Yu. A. Ferapontov M. A. Ul’yanova T. V. Sazhneva 《Russian Journal of Inorganic Chemistry》2008,53(10):1635-1640
The decomposition kinetics of peroxide products contained in the liquid phase of the LiOH-H2O2-H2O ternary system were studied, and the applicability of the solubility method to studying this system was demonstrated for hydrogen peroxide concentrations in the liquid phase from 2 to 6 wt % and temperatures of 21–33°C. The stabilizing influence of solid Li2O2 · H2O on hydrogen peroxide decomposition was demonstrated. The temperature and concentration boundaries of existence were determined for the Li2O2 · H2O phase, whose identity was verified by chemical analysis and qualitative X-ray powder diffraction analysis. 相似文献
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分别在MP2/3-21G!!、CCSD(T)/3-21G!!//MP2/3-21G!!和B3LYP/3-21G!!3种水平上,计算研究了气相反应Cl2 2HI=2HCl I2的机理,求得一系列四中心和三中心的过渡态.通过比较六种反应通道的活化能大小,得到了相同的结论:双分子基元反应Cl2 HI"HCl ICl和ICl HI"I2 HCl的最小活化能小于Cl2、HI和ICl的解离能,从理论上证明了反应Cl2 2HI=2HCl I2将优先以分子与分子作用形式分两步完成.用内禀反应坐标(IRC)验证了MP2/3-21G!!方法计算得到的过渡态. 相似文献
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采用密度泛函理论探讨了 TiO2 表面负载 Co2B2 和 Co2B2Pt 合金簇可能的负载构型. 结果表明, Co2B2 和 Co2B2Pt 合金簇倾向于以两个 Co 的形式负载在两个氧上. 态密度分析发现, 负载后, Co2B2 合金簇中部分 Co 原子和 B 原子成键加强, Co2B2Pt 合金簇中 Pt 原子和 B 原子成键也加强, 形成新的轨道. CO 和 O2 在 Co2B2/TiO2 和 Co2B2Pt/TiO2 表面吸附的结果表明, Co2B2Pt/TiO2 催化氧化 CO 性能的提高是由于 Pt 原子提高了 Co2B2 合金簇吸附 CO 和 O2 的能力. 相似文献
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报道了五元体系K2+2, Mg2+∥Cl2-2,SO2-4-CO(NH2)2-H2O在脲不饱和区及其边界四元体系MgSO4-MgCl2-CO(NH2)2-H2O在25 ℃时的等温溶度研究结果, 绘制了体系等温溶度的盐分组成图、水量图以及饱和溶液的折光率-组成图. 五元体系在脲的参与下, 交互反应K2Cl2+MgSO4→K2SO4+MgCl2向有利于生成硫酸钾和软钾镁矾K2SO4*MgSO4*6H2O(pic.)的方向进行, 这两者的相区较无脲时明显增大. 相似文献
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CO加氢反应机理一直是许多化学工作者感兴趣的课题.Rh催化剂因其优良的性能而被用于 CO加氢机理研 相似文献
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A neutral dinuclear compound Cu2[(O=PPh2)2N]2(μ-O2PPh2)2 has been unexpec- tedly prepared from the reaction of [Cu2(dppa)2(MeCN)4](ClO4)2 (dppa = bis(diphenylphosphino)- amine) and Sn(edt)2 (edt = ethane-1,2-dithiolate) in dichloromethane in air. ESR spectrum shows that the original Cu+ ion has been oxidized. The crystal structure determined by an X-ray single diffrac- tometer displays that the concurrence of the redox and hydrolysis of the origin ligand dppa is taken with the formation of two new ligands. The complex crystallizes in triclinic, space group P with a = 9.4269(13), b = 10.7522(13), c = 16.787(2)(A), ( = 92.042(5), β = 104.591(7), γ = 96.167(6)°, V = 1633.6(4)(A)3, C72H60 Cu2N2O8P6, Mr = 1394.12, Z = 1, Dc = 1.419 g/cm3, F(000) = 718, μ = 0.856 mm-1, the final R = 0.0530 and wR = 0.1096 for 4210 observed reflections with I > 2σ(I). 相似文献