Electron-gas interaction potentials for collisions of CaCl(X 2Σ+) and KCl(X 1Σ+) with Ar

Interaction potentials for CaCl(X ²Σ⁺)-Ar and KCl(X ¹Σ⁺)-Ar have been determined. They include a Gordon-Kim electron-gas repulsive part smoothly joined to the long-range van der Waals potential. The van der waals potential for KClAr was taken from Meyer and Toennies. For CaClAr, the necessary molecular parameter were estimated from the Rittner model, which predicts both the dipole and quadrupole moments fairly accurately. The CaClAr interaction potential is quite different from that of KClAr. Due to the outer 4s electron on the Ca⁺ ion. the CaClAr potential exhibits a deep minimum in the odd-order Legendre terms which is expected to have a large effect on the cross sections for collisional rotational excitation. The KClAr potential determined here also shows significant differences in the repulsive and well regions from that predicted by Meyer and Toennies using a site-site model for the repulsive contribution.     

Osmotic and Activity Coefficients of {yKCl+(1−y)MgCl2}(aq) at T=298.15 K

Isopiestic vapor-pressure measurements were made at the temperature 298.15 K for aqueous KCl + MgCl₂ solutions using KCl(aq) as the reference standard. The measurements for these ternary solutions were made at KCl ionic strength fractions of y=0.0, 0.1989, 0.3996, 0.5993, 0.7925 and 1.0 (with two additional sets at y=0.0, 0.2021, 0.3998, 0.6125, 0.8209 and 1.0) for the ionic strength range from 0.4014 to 6.2790 mol?kg^?1. Our results, and those from two previous isopiestic studies, were combined and used with previously determined parameters for KCl(aq) and those determined here for MgCl₂(aq) to evaluate mixing parameters for the Clegg-Pitzer-Brimblecombe model. These combined data were also used to determine the mixing parameters of the Scatchard model. Both sets of model parameters are valid for ionic strengths of I≤12.8 mol?kg^?1, where higher-order electrostatic effects have been included in the Clegg-Pitzer-Brimblecombe mixture model. The activity coefficients for KCl and MgCl₂ were calculated from these models and the results for KCl were compared to experimental data from Emf measurements. The Scatchard model interaction parameters were used for calculation of the excess Gibbs energy as a function of the ionic strength and ionic strength fraction of KCl. The Zdanovskii-Robinson-Stokes rule of linearity for mixing of isopiestic solutions was tested.     

Glass-forming region and structure in SiS2Li2SLiX (X = Br,I)

The glass-forming region in the SiS₂Li₂SLiX (X = Br, I) system, as determined by X-ray diffraction, has been extended to higher lithium content by the use of a direct liquid nitrogen quench. The base glass, 0.4SiS₂0.6Li₂S, was synthesized and doping up to 0.28SiS₂0.42Li₂S0.30LiBr and 0.24SiS₂0.36Li₂S0.40LiI was achieved. The properties of these glasses are compared to the glasses formed by previously reported quenching methods.Vibrational assignments have been made from infrared investigation of the glasses using FT-IR. The basic glass network consists of SiS₄ tetrahedra while the addition of Li₂S as a network modifier produced nonbridging sulfur. Doping with lithium halide did not significantly change the glass network, i.e., no changes in IR peak positions were observed. However, the higher lithium ion concentration resulted in higher mobility and ionic conduction.     

Localized vibrations of H−Na+H− impurity in KCl crystal

Localized modes due to H^?Na⁺H^? complex impurity in KCl crystal have been computed by a Green function method and compared with experimental data.     

Kalorimetrische untersuchung von binären legierungen des platins und palladiums mit gallium,indium und thallium

Employing tin and lead solution calorimetry, the formation enthalpies of those phases having platinum and palladium as major component have been determined in the PdGa, PdIn, PdTl, PtGa und PtIn systems. These enthalpies are highly exothermic and suggest strong atomic interaction betweens palladium and platinum on the one hand and the third subgroup elements on the other. The experimental values have been compared with those obtained from the Miedema model. The thermodynamic data are discussed and related to the crystal structures found with these alloys.     

三元体系NaCl-KCl-H2O35℃活度系数的研究

研究了35℃ NaCl-KCl-H2O三元体系的活度系数.用Na+、 K+和Cl-的离子选择性电极分别测得了(0.1～ 1.5 mmol/L)不同离子强度下该体系中NaCl和KCl的平均活度系数.回归了该体系Pitzer方程的相互作用参数.实验值与计算值最大相对误差为5.6%,而平均相对误差为2.3%.     

A study of the transport of ions against their concentration gradient across ion-exchange membranes using the network method

The network method has been used to analyze the conditions that favour the uphill transport across ion-exchange membranes. A model for the Nernst-Planck-Poisson equations describing the ionic transport in such system is proposed, including the Donnan equilibrium relations at the membrane/solution interfaces. With this model and the electric circuit simulation program PSPICE, the transient response of the system under open circuit conditions (I=0) and the response of the system subject to an applied potential difference are simulated. The ionic concentrations and electric potential profiles, as well as the electric current density, the ionic fluxes and the charge density, have been obtained as a function of time.     

The synthesis of diene and of vinyl copolymers containing predetermined quantities of polynuclear hydrocarbon or heterocyclic adducts—V. Copolymers formed from styrene or α-methylstyrene,anthracene and alkyl dihalide

When a tetrahydrofuran solution of styrene or α-methylstyrene (M) and anthracene (A) is reacted with alkali metal, anionic species are produced which can be titrated with alkyl dibromides (RBr₂) to produce copolymers. These copolymers have been analysed structurally by NMR spectroscopy and by a model compound approach.With styrene as monomer, the copolymers have been shown to consist of two types of repeat units [AM_nAR] and [AR] linked together in a random manner: at equimolar styrene to anthracene ratios, n ～ 10 and 75 per cent of the anthracene is linked directly to the alkyl ligand as in the second repeat unit. When α-methylstyrene is used, the repeat units are predominantly [M_nR] and [AR] with n ～ 5. Production of copolymers of α-methylstyrene in particular is more efficient for decane dibromide than for butane dibromide, where formation of bridged anthracene derivatives by a cyclization and regeneration of anthracene competes with the copolymerization.The reasons for the structural differences between the copolymers of the two vinyl monomers are discussed.     

壳聚糖·聚丙烯酸配合物半互穿聚合物网络膜及其对pH和离子的刺激响应

壳聚糖·聚丙烯酸配合物半互穿聚合物网络膜及其对ｐＨ和离子的刺激响应李文俊王汉夫卢玉华汪志亮钟伟（复旦大学高分子科学系聚合物分子工程开放实验室上海２００４３３）关键词高分子间配合物，互穿聚合物网络（ＩＰＮ），水凝胶，壳聚糖，刺激响应敏感性水凝胶是一种...     

External transverse magnetic field effect on electrolyte diffusion in NaClH2O solution

Experiments using modified membrane-cell method show that an externally applied magnetic field influences the integral diffusion coefficient of NaCl (measured at 25°C; 5,8 and 10 kG magnetic field strength and at ambient pressure) in 0.05, 0.1, 0.2, 0.5 and 1.0 N NaClH₂O solution.These findings verify the previously presented results showing that at the same thermodynamic state conditions, an applied external magnetic field of 5 kG strength alters the integral diffusion coefficient of KCl in 0.01, 0.1, 1,0, 2,0 and 3.0 N KClH₂O solutions.     

Thermodynamics of mixing in NaK β-aluminas

The activities of the components in the pseudo-binary NaK β-alumina system have been calculated from equilibrium ion-exchange data. Using data from exchanges with molten nitrate, chloride, and iodide salts, the results indicate that this system shows negative deviations from ideal mixing. A model involving preferential “ion pairing” of Na and K ions gives a good fit to the experimental data. Two maxima in the excess stabilities are found at compositions lying close to those which have been shown to exhibit the lowest ionic conductivities in the system. It is suggested that the “mixed-alkali” effect in NaK β-alumina is strongly related to the presence of cation order, and that the driving force for order results from reduction of nearest-neighbor cation repulsions.     

Aggregation work at polydisperse micellization: ideal solution and "dressed micelle" models comparing to molecular dynamics simulations

General thermodynamic relations for the work of polydisperse micelle formation in the model of ideal solution of molecular aggregates in nonionic surfactant solution and the model of "dressed micelles" in ionic solution have been considered. In particular, the dependence of the aggregation work on the total concentration of nonionic surfactant has been analyzed. The analogous dependence for the work of formation of ionic aggregates has been examined with regard to existence of two variables of a state of an ionic aggregate, the aggregation numbers of surface active ions and counterions. To verify the thermodynamic models, the molecular dynamics simulations of micellization in nonionic and ionic surfactant solutions at two total surfactant concentrations have been performed. It was shown that for nonionic surfactants, even at relatively high total surfactant concentrations, the shape and behavior of the work of polydisperse micelle formation found within the model of the ideal solution at different total surfactant concentrations agrees fairly well with the numerical experiment. For ionic surfactant solutions, the numerical results indicate a strong screening of ionic aggregates by the bound counterions. This fact as well as independence of the coefficient in the law of mass action for ionic aggregates on total surfactant concentration and predictable behavior of the "waterfall" lines of surfaces of the aggregation work upholds the model of "dressed" ionic aggregates.     

Validity of the electroneutrality and goldman constant-field assumptions in describing the diffusion potential for ternary electrolyte systems in simple,porous membranes

Three numerical algorithms capable of simulating transport processes through simple, porous membranes in the steady state have been employed in order to study the change in the diffusion potential with the membrane thickness and the ionic concentrations for the ternary systems NaClHClH20 and CaCI2NaC1H₂O. The first simulation procedure uses Poisson's equation, the two others replace this equation by the electroneutrality and Goldman constant-field approximations respectively. From the results presented here, conditions for the applicability of the electroneutrality and constantfield assumption to ternary electrolyte systems are given.     

NaCl(或KCl)-CH3OH-H2O体系的摩尔电导

CHaOH－HzO体系具有非常特殊的性质，同时在工业生产及临床治疗方面有着十分广泛的应用，文献中有大量地从不同角度就这类体系进行研究的报道．然而，就N3CI及KCI－CH30H－H20体系的电导研究而言，文献中仅有关干KCI－CH30H－H20（间隔20％CH30H）的部分研究工作．作为全面、系     

Normal coordinate analysis of bilirubin vibrational spectra: Effects of intramolecular hydrogen bonding

Normal coordinate analyses are presented for half-bilirubin molecules. Calculations for the AB pyrromethenone include intramolecular hydrogen bonds, while those for the CD chromophore exclude intramolecular hydrogen bonds. Valence force-field parameters have been optimized to correlate closely with the IR and Raman spectra of the target molecules. The results of the calculations are compared with the spectra of bilirubin IXa and various model compounds in the solid state and solution.     

H2O+KCl(饱和)+NaCl+NH4Cl的等压研究

Isopiestic measurements have been carried out at 298.15 K for the quaternary aqueous solution H2O+KCl(sat)+NaCl+NH4Cl saturated with potassium chloride and its ternary sub systems H2O+KCl (sat)+NaCl and H2O+KCl(sat)+NH4Cl. Taking sodium chloride (aq) or calcium chloride (aq) as reference solutions, osm otic coefficients and water activities of the aqueous solution were determined. The experiment results show that the isopiestic actions of the quaternary system related to its ternary sub-systems are in excellent agreement with the ideal like solution model.     

Supercooling of aqueous NaCl and KCl solutions under acoustic levitation

The supercooling capability of aqueous NaCl and KCl solutions is investigated at containerless state by using acoustic levitation method. The supercooling of water is obviously enhanced by the alkali metal ions and increases linearly with the augmentation of concentrations. Furthermore, the supercooling depends on the nature of ions and is 2-3 K larger for NaCl solution than that for KCl solution in the present concentration range: Molecular dynamics simulations are performed to reveal the intrinsic correlation between supercoolability and microstructure. The translational and orientational order parameters are applied to quantitatively demonstrate the effect of ionic concentration on the hydrogen-bond network and ice melting point. The disrupted hydrogen-bond structure determines essentially the concentration dependence of supercooling. On the other hand, the introduced acoustic pressure suppresses the increase of supercooling by promoting the growth and coalescence of microbubbles, the effective nucleation catalysts, in water. However, the dissolved ions can weaken this effect, and moreover the degree varies with the ion type. This results in the different supercoolability for NaCl and KCl solutions under the acoustic levitation conditions.     

The effect of temperature on thermoosmosis

Thermoosmosis through a collodion membrane (cm) and a poly(styrenesulfonic acid)—collodion interpolymer membrane (im) was observed, and changes in the mean temperature of the bulk solutions on both sides of the membrane and the KCl molality were recorded. The absolute value of the thermoosmotic coefficient, D, increased with increasing mean temperature. This was due to an increase in the fluidity of the KCl solutions. In all cases the direction of thermoosmosis was from the cold side to the hot side. For the charged membrane (im), the molality dependence of D was larger than that for the collodion membrane (cm).     

羊抗人IgG在金纳米通道中的迁移

以聚碳酸酯超滤膜为基板,用化学镀的方法在超滤膜上沉积金,制得直径在45nm左右的金纳米通道阵列,利用制得的金纳米通道阵列搭建离子电流测量平台,可实现对羊抗人IgG分子的浓度检测.当羊抗人IgG分子通过直径45nm的金纳米通道时,由于物理占位及表面电荷的影响,会引起离子电流发生变化;在KCl浓度为0.15mol/L(pH7.48)溶液中,IgG分子的物理占位对离子电流有阻塞作用,会导致电流减小,IgG浓度在1.8～18ng/mL范围内,减小量与浓度成线性关系;实现了对IgG的定量检测.KCl浓度降低到0.025mol/L时,由于IgG分子扩散层内反离子对通道内离子浓度的贡献占主导地位,从而造成离子电流随着IgG浓度增大而增大.     

NaCl、KCl在CH3OH+DMF或DMSO混合溶剂中的溶解度, 278、288、298、303、313 K

本工作测定了NaCl、KCl在CH_3OH与DMF及CH_3OH与DMSO全组成范围混合溶剂中的溶解度。实验温度分别是; 对NaCl:278、288、298、303、313 K, 对KCl:288、303、313 K。随着溶剂组成变化KCl和NaCl的溶解度曲线皆有一极大值。溶解度温度系数分别为正和负, 随着溶剂中CH_3OH组份的减少温度系数减小。根据实验结果, 计算得NaCl和KCl自甲醇至混合溶剂的转移自由能和熵。对离子在此混合物中的溶剂化、结构影响和盐的溶解倾向作了初步解释。