2，6－二氯－4－硝基苯氨基重氮偶氮苯的合成及与镉（Ⅱ）显色反应的研究

本文合成了新试剂２，６－二氯－４－硝基苯氨基重复偶氮苯（ＤＣＮＡＤ）。研究了在吐温８０存在下ＤＣＮＡＤ与Ｃｕ（Ⅱ）的显色反应，结果表明在ｐＨ为１０．０～１０．８内ｃｕ（Ⅱ）与ＤＣＮＡＤ形成稳定的１：２配合钧，其最大吸收峰位于５９０ｎｍ，摩尔吸光系数为１．９×１０￣５１．ｍｏｌ￣（－１）．ｃｍ￣（－１），Ｃｄ（Ⅱ）的量在０～０．９μｇ／ｍｌ内符合比耳定律。以氟化钠－酒石酸钾钠－硫脲为掩蔽剂，方法具有较高的选择性，用于水样中微量镉的测定，获得了较好的结果。     

热活化胶状黄铁矿去除酸性溶液中的Cd(Ⅱ)

利用XRD和SEM测试方法表征了热活化胶状黄铁矿结构和微观形貌,考察了溶液pH、溶解氧和热活化温度对热活 化胶状黄铁矿去除水中Cd（Ⅱ）的影响,并探讨了除Cd（Ⅱ）反应动力学和作用机理。胶状黄铁矿在N2氛围下650℃热活化 5 min可完全分解生成多孔结构化单斜磁黄铁矿（PMPyr）。在pH 2~6的无氧水溶液中PMPyr除Cd（Ⅱ）效率均达到88%以 上,除Cd（Ⅱ）效率受pH影响较小;PMPyr表面氧化会抑制其与Cd（Ⅱ）的反应。PMPyr除Cd（Ⅱ）动力学可用准二级动力学模型拟合（R2> 0.9992）,结合溶液pH变化趋势、Fe（Ⅱ）和SO42-浓度变化推测,PMPyr除Cd（Ⅱ）机理主要是Fe1-xS和CdS溶度积差异推动了PMPyr与Cd（Ⅱ）交换反应,表面络合属于次要作用。     

A variationally consistent hyperstatic reaction method for tunnel lining design

In this technical note, a consistent finite element formulation of the Hyperstatic Reaction Method (HRM) for tunnel linings design is proposed by introducing a variational consistently linearized formulation. It permits to consider a nonlinear interaction between a lining structure and the surrounding ground. Recent advances of the HRM in regard to the consideration of the nonlinear response of the segmented tunnel lining exposed to design loads use an iterative algorithm for solving the nonlinear system of equations. In the proposed Variationally consistent Hyperstatic Reaction Method (VHRM), a distributed nonlinear spring model representing the interaction between the lining and the ground soils is considered in a variationally consistent format. Computing the tangential spring stiffness via consistent linearization, and using Newton-Raphson iteration, requires significantly smaller number of iterations as compared to the original HRM model based on nodal springs. Furthermore, the method is applicable for simulations using solid finite elements (2D and 3D), as well as beam or finite shell elements, respectively.     

近平衡状态海水中方解石和文石沉淀速率及动力学研究

利用"freedrift"开放反应系统,研究人工海水中近沉淀平衡状态时二氧化碳分压(p(CO2))的变化对方解石、文石沉淀速率及其动力学方程的影响.反应在恒定的温度(25.0℃±0.2℃)、p(CO2)环境下进行,通过实验得到了不同p(CO2)环境下,方解石和丈石的沉淀速率及动力学方程.研究发现:(1)晶体类型和碳酸盐...     

氧气反应模式-电感耦合等离子体串联质谱法测定土壤中的镉

应用电感耦合等离子体质谱法(ICP-MS)分析土壤中的镉元素时,锆的氢氧化物、钼的氧化物、锡的同位素会对镉造成严重的干扰,导致准确测定土壤中镉的难度较大.本文采用电感耦合等离子体串接质谱法(ICP-MS/MS),选取无同质异位素干扰的111 Cd为分析谱线,在MS/MS模式下碰撞反应池中通入的氧气可以与94Zr16O1...