Sr／Ca比变化对红色荧光粉Ca1-xSrxS：Eu^2＋的影响

在CO气氛下采用固相反应法合成了发红光的Ca1-xSrxS:Eu^2 荧光粉，研究了基质阳离子Sr／Ca比变化对其晶体性质及发光性能的影响。结果表明，随着Sr／Ca比的减少，荧光粉的晶胞参数逐渐降低；同时，由于受电子云膨胀效应和晶体场影响，发射主峰向长波方向移动，红色比逐渐增大，色纯度提高。     

磺酰胺类常咯啉的分子力学参数的确定

应用量子化学ＭＮＤＯ程序及分子力学ＭＭＰ２程序，确定了一些未知磺酰胺类常咯啉的分子力学参数。应用这些参数计算了几个晶体结构已知的磺酰胺类化合物，与真实结构比较，计算结果令人满意。由此说明确定的分子力学参数用于计算磺酰胺类化合物时的正确性和可行性。     

基本参数法在能量色散X射线荧光分析金属样品中的应用

在X射线荧光分析中,基本参数法是校正元素间吸收增强效应的数学方法之一。我们使用带有不锈钢窗的~(241)Am59.6keVγ射线作为激发源,用Si(Li)半导体探测器和多道脉冲幅度分析器作为实验手段。采用无标样法,即绝对测量法,因而具有更大的广泛性和实用性。实验中,我们除了考虑元素间的二次、三次荧光吸收增强作用外,对样品中元素     

New uniform algorithm to predict reversed phase retention values under different gradient conditions

A new numerical emulation algorithm was established to calculate retention parameters in RP-HPLC with several retention times under different linear or nonlinear binary gradient elution conditions and further predict the retention time under any other binary gradient conditions. A program was written according to this algorithm and nine solutes were used to test the program. The prediction results were excellent. The maximum relative error of predicted retention time was less than 0.45%.     

定标粒子理论预测乙醇－水体系汽液平衡盐效应

测定了７０℃下３个１－１型电解质（ＮａＣｌ、ＮａＢｒ、ＫＣｌ）在各种不同浓度的乙醇－水体系中的汽液平衡盐效应参数，并给出用定标粒子理论计算盐效应参数的方法。硬球作用项采用Ｍａｓｔｅｒｔｏｎ－Ｌｅｅ方程，软球作用项采用胡英的径向分布函数。分子间力在Ｌｅｎｎａｒｄ－Ｊｏｎｅｓ位能函数基础上计入偶极－偶极、偶极－诱导偶极、电荷－偶极、电荷－诱导偶极的贡献，其中离子－分子间的静电作用项仅限于规则排列的第一配位圈之内。将混合溶剂的局部介电常数视为液相浓度的函数，函数关系由实验拟合。在乙醇浓度变化的很大范围内，３个体系的预测与实验结果基本相符。     

计量置换参数Z值分量的测定(英文)

 以计量置换吸附理论(SDT A)为基础,从理论上推导出计量吸附模型中表征溶质对固定相亲合势大小的参数βa值与流动相中强置换剂浓度的对数呈线性关系。计量置换模型中的参数n和q(n和q分别代表1摩尔溶剂化溶质被吸附时,从吸附剂表面和从溶质分子表面所释放出的溶剂的物质的量)是计量置换参数Z值的分量,是两个非常有用的参数,可以从这个定量关系中直接获得。推导出的方程用苯的衍生物进行了实验验证,获得了较满意的结果。将这种方法计算得到的分量值与SDT A与计量置换保留模型(SDT R)相结合的方法得到的分量值进行了比较。     

The Effect of Alkane Chain Length on the Liquid–Liquid Critical Temperatures of Oligostyrene/Linear-Alkane Mixtures

Summary. Upper critical solution temperatures (UCSTs) for liquid–liquid demixing in a set of mixtures of linear alkanes (pentane (N ₁=5) to pentacontane (N ₁=50)) with an oligostyrene (1241amu, N ₂=12) are reported. We find strong correlation between the Hildebrand solubility parameters of the alkanes and the UCST. Correlations are developed which enable predictions concerning the miscibility of mixtures of compounds with longer chains.     

Studies on the thermodynamics of solvent extraction of indium (III) with HDEHMTPCA

The equilibrium molalities In³⁺ in {In₂(SO₄)₃ + Na₂SO₄ + HDEHMTPCA + n-C₈H₁₈ + water} were measured at ionic strength from (0.1 to 2.0) mol · kg⁻¹ containing Na₂SO₄ as supporting electrolyte in aqueous phase and at constant molality extractant at temperatures from (278.15 to 303.15) K in organic phase. The standard extraction constants K⁰ at various temperatures were obtained by methods of extrapolation and polynomial approximation. Thermodynamic quantities for the extraction process were calculated.     

Value function and optimality conditions for semilinear control problems

This paper is concerned with optimal control problems of Mayer and Bolza type for systems governed by a semilinear state equationx(t)=Ax(t) + f(t, x(t), u(t)), u(t) U, whereA is the infinitesimal generator of a strongly continuous semigroup in a Banach spaceX. We prove necessary and sufficient conditions for optimality and then use these conditions to investigate properties of the value function related to superdifferentials. Conversely, we use the value function to obtain criteria for optimality and feedback systems.Work (partially) supported by the Research Project Equazioni di evoluzione e applicazioni fisicomatematiche (M.U.R.S.T.-Italy).