刚柔组合桩复合地基加固设计与应用

利用柔性桩减少刚性桩与土之间的刚度差,使之与土结合良好,达到提高复合地基承载力特征值和柔性桩软土地基加固的置换率、减少刚性桩复合地基变形及降低软地基处理造价等目的.将水泥土柔性短桩中心用沉管桩的工法施工低强度（C10）砼桩——＂刚柔组合桩＂的复合地基,处理宁波北仑某仓库的软土地基,经检测、计算验证和经济型比较,表明刚柔组合桩复合地基法可应用于软土地基工程,且能降低造价.     

基于2-(5-碘-2-吡啶偶氮-2-二甲氨基苯胺)捕获钴构置的肼传感器

将新型显色剂2-(5-碘-2-吡啶偶氮-2-二甲氨基苯胺)(5-I-PADMA)修饰在ITO玻璃电极上以捕获溶液中的钴离子,再将其在电极上原位还原,制备了纳米钴/ITO修饰电极,基于此建立了测定肼的电化学传感新方法。通过循环伏安法和安培法,对比研究了有无5-IPADM A的两种传感器的构置及传感响应。实验结果表明:5-I-PADM A形成的修饰膜,可以高稳定存在,并有效捕获溶液体系中的钴离子,构置的传感器性能显著优于无显色剂的情况。该结果表明,将显色剂引入电化学体系,在完成传统的重金属污染处理的同时,可以二次利用富集后的金属离子,实现对一些电活性物质环境污染物的测定。     

索伦森与pH

1909年丹麦生物化学家索伦森提出的pH概念及其测试方法,保证了啤酒产业中产品质量和风味的统一。由于科学概念的简捷性和严密性,pH概念在国内外传播中产生了一些理解上的歧义;pH试纸在使用中出现了化学知识内涵不清的问题,通过回顾历史,恢复其本来面目,促进化学教学规范发展。     

基于配位调控机制的纳米钴电化学传感研究

以钴离子(Co2+)与5-(5-碘-2-吡啶偶氮)-2,4-二氨基甲苯(5-I-PADAT)形成的配合物(Co2+-5-IPADAT)为支持电解质,采用循环伏安法,扫描电位范围-1. 5～0. 5 V,沉积50圈,制备获得Co NPs-5-I-PADAT修饰电极。采用扫描电子显微镜成像、X射线晶体衍射对其形貌及组成进行分析,并研究其对肼的电催化氧化行为。结果表明:在p H 7. 0的磷酸缓冲溶液中,电压位于0. 55 V处呈现显著的肼氧化峰。据此,建立了肼的定量分析方法,其线性范围为0. 64～2 150μmol/L,相关系数为0. 998 0,检出限(S/N=3)为0. 28μmol/L,回收率为95. 3%～102%。Co NPs-5-I-PADAT/GCE修饰电极具有良好的稳定性和选择性,可满足环境样品中肼的检测需求。     

Theoretical Investigation of Structures,Bonding and Electronic Properties for the Complexes of 6-Mercaptopurine and Ag_8 Clusters

The Ag clusters have been investigated widely theoretically and experimentally. In particular, it has recently shown that the neutral Ag_8 clusters embedded in an argon matrix have a strong fluorescence signal. As we can know, the metal clusters may have important effects on the structures and properties of biomolecules. More and more attention is paid to the interaction between nanomaterials and biomolecules. In this work, the B3LYP method in density functional theory was used on the complexes between the 6-mercaptopurine(6MP) and Ag_8 clusters combined with 6-311++G** as well as LANL2DZ base sets. The geometries of all the complexes were optimized with full degree of freedom and the structures, chemical bonds, orbital properties as well as Mulliken charges for ten possible complexes were analyzed based on the same theory level. In addition, the influence of temperature and pressure on the stabilities of the four complexes was further explored using standard statistical thermodynamic methods ranging from 50 to 500 K and at 100 kPa or 100 bar. The results show that the complex Ag_8-6 MP-7-5 can be the most stable one among the investigated complexes, in which the Ag(11) atom interacts with the S(10) atom forming the strong chemical bond. The Mulliken charges also show that the Ag–S chemical bond is formed and the related charge has transferred. Additionally, the temperature and pressure can significantly influence the stability of the four stable complexes.