氯化钠在球形纳米氧化铈形成过程中的作用

以水合碳酸铈为原料, 以氯化钠作为助磨剂和阻聚剂, 采用机械活化法制备了球形纳米氧化铈, 用XRD法研究了水合碳酸铈与氯化钠质量比、球磨时间、煅烧温度对CeO2粉体晶粒度的影响, 用TEM对最终产物粒子进行形貌观察. 结果表明: 在碳酸铈的球磨过程及其随后的煅烧过程中, 氯化钠的存在起到了很好的助磨和阻聚作用, 所得CeO2为类球形粒子, 分散性较好, 晶粒度约为30～50 nm.     

氯化铯和氯化镧溶剂体系及四类新化合物的合成

研究了四元体系ＣｓＣｌ－ＬａＣｌ３－ＨＣｌ－Ｈ２Ｏ（２５℃、「ＨＣｌ」＝１３％（ｗｔ），２３％（ｗｔ）和ＣｓＣｌ－ＬａＣｌ３－ＨＡｃ－Ｈ２Ｏ（３０℃，「ＨＡｃ」＝４２％（ｗｔ））的平衡态的溶度数据，并给出制了相应的溶度图，共得到了ＣｓＣｌ．ＬａＣｌ３．４Ｈ２Ｏ、２ＣｓＣｌ．ＬａＣｌ３．２Ｈ２Ｏ和３ＣｓＣｌ．ＬａＣｌ３．３Ｈ２Ｏ３种化合物。对得到的新相进行了热分析，Ｘ射线粉末衍射及偏光性质的测定，依     

Vapor pressure,speciation, and chemical activities in highly concentrated sodium borate solutions at 277 and 317°C

The system H₂O-B₂O₃-Na₂O has been studied experimentally at 277 and 317°C. The activities of water and boric acid have been determined at mole ratios Na/B from 0 to 1.5, and total dissolved solids 3 to 80 weight percent. The activity of boric acid has been fitted to within experimental error using a speciation model with eight complex species. This model is consistent with the model previously published by Mesmer et al. The electrolyte properties of the liquid are modeled using the Pitzer-Simonson model of very concentrated electrolyte solutions. The calculated values of water activity agree with experiment, and the activity of NaOH and pOH have also been calculated. The potassium borate system also was briefly studied at 317°C, and is adequately described by a model with five complex species. The potassium borate liquid is more alkaline at K/B= 1 than a sodium borate liquid at the same mole ratio, but pOH in the two systems is the same at lower mole ratios.     

丙醇-氯化钠双水相体系萃取分离铂、钯、铑、金中的铱及其吸收光谱分析研究

提出了一种丙醇－氯化钠双水相体系萃取铱的分离－吸收光谱分析方法，在HCl介质中基于铱生成三氯亚锡酸络阴离子动力学速率与铂、钯、铑、金差异使铱与铂、钯、铑、金分离，其后在KI介质中萃取铱使其与贱金属基体分离，研究了在丙醇萃取相中铱的吸收光谱分析，并应用于实际样品中铱的测定。     

电动势法测定Cu(Ⅰ)与乙炔生成配合物的热力学函数

乙炔与Cu(I)生成配合物的热力学函数文献报道鲜见,且不同作者的测定结果差异较大。本文用改进的电动势法。对在氯丁橡胶、聚氯乙烯,乙醛等工业过程有重大意义的Cu(I)与乙炔配合物进行测定,得到更合理的结果。     

Dealkylation ofpara-nitrophenyldimethyl thiophosphate in micellar and liquid-crystalline media of then-decylammonium chloride-n-decylamine-water system

The kinetics of decomposition of p-nitrophenyldimethyl thiophosphate (1) were investigated spectrophotometrically in the n-decylammonium chloride-n-decylamine-water system (DAC-DA-H₂O), in which micellar or lamellar liquid-crystalline phases are formed as a function of the concentration of components. It was shown that1 is dealkylated in both phases. An increase in the surface charge density of associates decreases the rate of dealkylation. The activation energy in the lamellar phase is significantly higher than in the micellar phase.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1042–1048, May, 1992.     

Re-Evaluation of the Activity Coefficients of Aqueous Hydrochloric Acid Solutions up to a Molality of 2.0 Using Two-Parameter Hückel and Pitzer Equations. Part I. Results at 25°C

Simple two-parameter Hückel and Pitzer equations were used for the calculation of the activity coefficients of aqueous hydrochloric acid at 25°C up to a molality of 2.0 mol-kg^–1. The data obtained by Harned and Ehlers^(12,13) from galvanic cells without liquid junction were used in the analysis and the parameters obtained were compared to those obtained from all reliable data presented in the literature for HCl at this temperature. A good agreement between the parameters was always observed. The activity coefficients obtained by the new equations were compared to those suggested by Robinson and Stokes,⁽⁸⁾ Hamer and Wu,⁽¹⁾ and Pitzer and Mayorga,⁽⁹⁾ and good agreement was also found. The data from the most important literature data sets for HCl were also predicted using the new activity coefficient equations, and the magnitude of the resulting errors was close to the precision of the measurements, the errors forming an almost random pattern for all data sets.     

Solid-phase microextraction–capillary gas chromatography combined with microwave-induced plasma atomic-emission spectrometry for selenite determination

The use of solid-phase microextraction (SPME) with gas chromatography coupled to microwave-induced plasma atomic-emission detection (GC–MIP-AED) is described for selenite [Se(IV)] speciation. Aqueous standards were derivatised with sodium tetraethyl- or tetrapropylborate and extracted by SPME. Headspace extraction of the ethyl and propyl derivatives was studied. Relevant experimental conditions were optimised, including conditions for derivatisation and extraction and those of gas chromatographic analysis. The limits of detection achieved for headspace sampling of derivatised Se(IV) were in the low ng mL^–1 range for both ethylation and propylation. When the method was applied to analysis of selenite in selenised yeast reference material results were in good agreement with the indicated values.     

NaAg3S2, ein Thioargentat mit dem Clusteranion [Ag6S4]2−

NaAg₃S₂, a Thioargentate Containing the Anionic Cluster [Ag₆S₄]^2? . Dark-red octahedrally shaped crystals of NaAg₃S₂ could be obtained by the reaction of NaAg(CN)₂ and NaCN in a stream of hydrogen sulfide at 630 K. NaAg₃S₂ crystallizes cubic, a=12.358(1) Å, space group Fd3 m, Z=16. The structure was determined from four-circle diffractometer data. NaAg₃S₂ contains the anionic cluster [Ag₆S₄]^2?. The structure can be traced back to the spinel structure typ. An extended Hückel calculation for the cluster anion, which is considered to be isolated, shows weak bonding silver-silver interactions. NaAg₃S₂ is diamagnetic at room temperature.     

反胶束笼对纳米氯化银反应性能的微环境限定

研究了反映束中直径为１０￣１７ｎｍ的ＡｇＣｌ微料与亚甲基蓝之间的作用，比较了阴离子型和非离子型表面活性剂组成的反胶束微环境的影响，讨论了亚甲基蓝在粒子上的吸附，二聚体形成的钠米ＡｇＣｌ粒子对亚甲基蓝荧光猝灭机制。