乙二醇和水混合溶剂多组分电解质热力学

在乙二醇和水混合溶剂中恒定乙二醇质量分数w=0.1的条件下，应用经典的电动势方法测定无液体接界电池的电动势: Pt，H2 (105 Pa )│HCl (质量摩尔浓度m)， C2H6O2 (w), H2O (1－w)│AgCl-Ag (A) Pt，H2 (105 Pa )│HCl (mA), NaCl(mB), C2H6O2 (w), H2O (1－w)│AgCl-Ag (B) 根据测得电池(A)的电动势，确定混合溶剂中AgCl-Ag电极的标准电极电势，讨论了HCl的迁移性质.利用电池（B）的电动势，计算出HCl的活度系数γA.结果表明，在溶液中总离子强度保持恒定， HCl的活度系数服从Harned规则.在溶液组成恒定时， lgγA是温度倒数1/T的线性函数. 进一步讨论了混合物中HCl的相对偏摩尔焓和介质效应.     

反相高效液相色谱法测定改性单基发射药中的N，N-二苯基-N＇-甲基脲素

建立了反相高效液相色谱测定改性单基发射药中N,N-二苯基-N＇-甲基脲素（AKⅡ）含量的方法。采用ODS色谱柱（150mm×4．6mm,5μm）,选用甲醇-水（体积比60：40）体系为流动相,检测波长为220nm,流速为1mL／min,柱温为室温,用水析法进行紫外检测定量测定。结果表明,AKⅡ浓度在0．09～0．5mg／mL范围内与色谱峰面积比值（分析物：内标）呈良好的线性关系,线性方程为y=65．058x＋0．0439,相关系数t=0．9989。测定结果的相对标准偏差为1．10％（n=8）,加标平均回收率为99．77％。采用内标法测定改性单基发射药中N,N-二苯基-N＇-甲基脲素的含量,结果准确可靠,操作简单实用。     

添加剂对化学沉积速率的影响

基于化学镀Ni-W-P和Ni-P体系中,添加剂LaCl3、乳酸、Fe2(SO4)3、硫脲和2,2’-联吡啶的浓度对沉积速率的影响表现出较为一致的变化规律,即随添加剂浓度的增加,出现最大沉积速率的实验事实,建立了一种吸附模型并导出添加剂加速化学沉积的公式.根据该公式和实验结果进行曲线拟合,得到相当吻合的结果.由拟合结果可得到一些参数值,如吸附平衡常数等.添加剂在基体上的吸附平衡常数(K1)大于已吸附了还原剂的表面上的吸附平衡常数(K2). K1值大表明添加剂在基体表面吸附能力更强. LaCl3、硫脲和2,2’-联吡啶的K1、K2值远大于乳酸、Fe2(SO4)3的K1、K2值,这表明LaCl3、硫脲和2,2’-联吡啶的吸附能力远强于乳酸、Fe2(SO4)3的, 因此,LaCl3、硫脲和2,2’-联吡啶所引起的沉积速率峰值的浓度远小于乳酸、Fe2(SO4)3的.     

ICP–OES法检测玩具涂层中17种可迁移元素

建立了电感耦合等离子体发射光谱法(ICP–OES)法同时测定玩具涂层中17种可迁移元素的方法。样品经盐酸溶液提取,利用ICP–OES进行测定。砷、镉、钴、铬、镍、铅、锑、硒元素的线性范围为0.02~2 mg/L,铝、硼、钡、铜、锡、锶、锌、锰的线性范围为0.1~10 mg/L,汞的线性范围为0.02~0.5 mg/L,线性相关系数r≥0.996。方法检出限为0.000 2~0.015 9 mg/L,加标回收率为90.1%~108.1%,重复测定结果的相对标准偏差为0.23%~2.23%(n=6)。该方法简便、快速,具有较高的准确度和良好的精密度,适用于大多数玩具材料中17中可迁移元素的检测,能满足欧盟玩具安全指令的要求。     

金属介电函数的正确运用——以金属纳米球诱导的二能级系统的基态能级移动为例

金属对电磁场的响应包括自由和束缚电荷两部分的贡献,大学物理教学中通常分别用Drude模型和Lorentz模型描述,然而,以上模型所得的介电函数只在一段较窄的频率范围内能与实验数据吻合.因此,在实际科研工作中,当物理量与较宽频率范围内的电磁场响应有关时,原则上介电函数应当采用实验测量值而不能采用模型化的结果.本文以金属纳米球诱导的二能级系统的基态能级移动为例,分别展示采用模型化的介电函数和实验介电函数时,能级移动计算结果的差异.     

Brans-Dicke引力理论的弱场近似

Brans-Dicke引力理论是重要的修正引力理论之一,其对于研究星体运动、宇宙演化以及解释宇宙现象等起着重要的作用.寻找Brans-Dicke引力理论场方程的解对于Brans-Dicke引力理论的研究和发展具有重要意义.但由于Brans-Dicke引力理论场方程本身的高度非线性性,使得一般情况下精确求解非常困难,特殊情况下也只能求得部分精确解.幸运的是大多数情况下引力场比较弱,且在低速的条件下求场方程的近似解相对容易.本文基于弱场低速条件,详细地求解了Brans-Dicke引力理论的弱场低速近似解.首先基于弱场条件,将标量场和度规写为一阶微扰展开的形式;然后将标量场和度规代入相应的场方程得到相应的线性场方程,通过选取特定的规范条件进一步简化线性场方程;最后求解出简化的线性场方程的低速近似解.本文的求解方法可以为Brans-Dicke引力理论的教学和研究提供有益的参考.     

任意n阶多边形电阻网络的电特性研究

文章采用基尔霍夫定律通过建立差分方程模型的方法研究了一类任意n阶多边形电阻网络的电学性质(节点电压,支路电流,等效电阻).首先采用基尔霍夫节点电流定律建立差分方程模型,同时建立边界条件方程,以此研究差分方程组的通解和特解,进而获得各节点电压公式,并且基于电压结果导出支路电流公式及等效电阻公式.本文的研究工作对于促进基础物理创新教学具有很好的理论意义与教学实践价值.     

希罗喷泉动力学分析

本文构建了一个希罗喷泉系统,利用修正后的非定常伯努利方程及连续性方程,在层流与非定常的基本假设下,解出其动力学方程;使用Mathematica软件并结合实验参数进行数值求解,推导了喷射高度随时间的理论变化关系,并探讨了喷射瓶的相对放置高度、横截面积、喷射管道直径以及喷口高度等参量对喷泉高度的影响.同时运用Tracker软件追踪喷泉高度,建立了空气弹簧的模型,完成了理论与实验的相互验证.     

Hydrodynamic forces and moments due to interaction of linear water waves with truncated partial-porous cylinders in finite depth

An exact analytical method is employed for studying the diffraction problems in an ocean due to the presence of a specific type of cylinders. In this current work, two models are studied: (i) a floating surface-piercing truncated partial-porous cylinder, (ii) a surface-piercing truncated partial-porous cylinder placed at the bottom. In both cases, the configuration of the composite cylinder is such that it consists of an impermeable inner cylinder rising above the free surface and a coaxial truncated porous cylinder around the lower part of the inner cylinder with the top of the porous cylinder being impermeable. By using linear water wave theory, a three-dimensional representation of the problem is developed based on eigenfunction expansion method. The condition on the porous boundary is defined by applying Darcy’s law. Pressure and velocity satisfy continuity conditions across the linear interface between the adjacent fluid domains. Hydrodynamic force, moment and wave run-up are calculated by using the velocity potentials. Comparisons are carried out with results of wave diffraction by a floating and bottom-mounted compound cylinder, i.e., when the whole cylinder is non-porous. Handy agreements are observed from these comparisons. Through numerical tests, various experiments are carried out to investigate the impact of various parameters, such as porous coefficients, draft ratio, the ratio of inner and outer radii, the water depth etc., on hydrodynamic force, moment and wave run-up. The results clearly indicate that an appropriate optimal ratio for various parameters may be considered in designing practical ocean structures with minimum adverse hydrodynamic effect. The appearance of resonance in the results and role of porosity in mitigating resonance effect are explained. Proposal to select various appropriate parameters for the best possible effect is put forward.     

Adsorption Capacity of Poly[4-Methacroyloxy-(4’-Carboxy-3-СHloro)-Azobenzene], In Situ Immobilized on the Silica Gel Surface to Toxic Metals Ions

Abstract

By mean of heterophase polimarzation on the silica gel surface has been made in situ immobilization of poly[4-methacroyloxy-(4’-carboxy-3-Сhloro)-azobenzene] and has been received new organic-mineral composit material. The fact of polymer immobilization has been confirmed by IR spectroscopic method and thermogravimetric analysis combined with mass spectrometry. According to the results of thermogravimetric analysis, has been found the mass of the immobilized polymer is 13.33%.

The synthesized composite revealed sorption activity to the ions of Cu (II), Pb (II) and Fe (III) micro quantities in a neutral water environment. Maximum sorption ions Cu (II), Pb (II) and Fe (III) degree is reached during first contact hour in static sorption condition. According to the results of isotherms sorption treatment has been determined the silica gel surface poly [4-methacryloxy- (4'-carboxy-3-chloro)-azobenzene] modification led to the sorbtion volum Cu (II) ions more than 1.5 times, for ions Pb (II) - 3.6 times, but for Fe (III) ions - almost 2 times.