硝基苯还原羰化反应制备氨基甲酸酯选择性的研究

在硝基苯还原羰化反应和还原反应的竞争中，使用高分了载体，加人第二金属 组分，升高反应温度有利于还原羰化反应的进行．并且实现了利用双金属效应，在 不含有机配体的体系中高选择性地进行硝基苯还原羰化反应．     

Co-Cr水滑石的合成及其衍生双金属氧化物催化活性研究

用低饱和共沉淀法合成了不同Co/Cr摩尔比的水滑石类化合物，采用XRD，IR，DTA－TG，分光光度法对其结构进行了表征，并以其为前体分别经350℃,450℃灼烧处理得双金属氧化物催化剂，用乙醇脱水、脱氢为探针反应，研究了其催化活性。     

The explosive working of materials in the USSR

Abstract

The studies of the processes related to working the materials by explosive energy were initiated in the Soviet Union during the World War II. The process of armour piercing by shaped charges developed at the beginning of the twentieth century in the United States and in Germany was investigated. The investigations were carried out by a research team of Academician M. A. Lavrentiev in Kiev in 1944–1946 and several modifications of the explosive welding phenomenon were detected'. In the mid-fifties, investigation of explosive powder compaction were begun in Moscow by Professor Yu. N. Riabinin². In the early sixties, M. A. Lavrentiev undertook a large-scale research program on explosive hardening and welding in Novosibirsk¹. Later, explosive powder compaction was also included into the research program³. The first attempts to investigate the strength of the explosive chambers relate to the same period⁴.     

AgPd双金属纳米空心球的合成及其催化性能

以Ag纳米颗粒为牺牲模板,H₂PdCl₄为前驱体,抗坏血酸为还原剂,聚乙烯吡咯烷酮为表面活性剂,在70 ℃下采用电偶置换法结合还原法制备出AgPd双金属纳米空心球。采用紫外可见光谱、粉末X射线衍射、透射电镜结合能量色散等手段对由不同体积的0.01 mol·L^-1 H₂PdCl₄溶液制备的产物进行结构表征。结果表明,随着H₂PdCl₄溶液体积的增加,产物的空心化程度逐渐升高,晶粒的尺寸逐渐增大。当 H₂PdCl₄溶液体积为 120 μL时,合成的 AgPd双金属纳米空心球组成和结构较为均匀,其粒径约为 25 nm,壳层厚度 2~3 nm。双金属中,由于 Ag 和 Pd 电负性的差异,电子从 Ag 转移到了 Pd,使 Pd 表面出现电子富集区,显著提高了其催化效率。将所合成的AgPd双金属以及纯金属Ag和Pd作为催化剂,分别用于硼氢化钠催化还原4-硝基苯酚的反应,发现AgPd双金属的催化性能远高于纯金属Ag和Pd,其中AgPd-120纳米空心球(H₂PdCl₄溶液体积120 μL)作催化剂时的反应速率常数最高,是同等尺寸纯Ag纳米球的24.0倍,纯Pd纳米立方体的14.7倍。     

Graphene nanosheet as support of catalytically active metal particles in DMC synthesis

Novel graphene nanosheet(GNS) supported Cu-Ni bimetal catalysts were firstly synthesized and used for the direct synthesis of dimethyl carbonate(DMC).The experimental results demonstrated that GNS was an effective and convenient support for the fabrication of Cu-Ni/GNS bimetal catalyst.     

双金属纳米天线在少周期激光中的宽带超快电磁响应

研究了耦合的核壳双金属纳米粒子天线的光场增强与超快时域响应. 在少周期激光的应用中, 如表面等离激元金属纳米器件中的超快响应探测元件, 这种双金属天线展示了超宽带共振频谱及控制局域表面等离激元增强的能力. 研究了二聚体、三聚体以及七聚体, 并且发现三聚体Ag/Au核壳结构显现了极高的场增强能力, 其场振幅增强因子超过了120, 并在5 fs的时间内场振幅迅速衰减为30, 保持了超快的光学响应特性. 利用该结构的表面等离激元增强效应产生高次谐波, 对于产生超快阿秒脉冲有着潜在的重要应用价值. 关键词： 纳米光学天线 双金属球壳结构 少周期激光脉冲 表面等离激元     

Mn−O Covalency Governs the Intrinsic Activity of Co‐Mn Spinel Oxides for Boosted Peroxymonosulfate Activation

Transition metal (TM)‐based bimetallic spinel oxides can efficiently activate peroxymonosulfate (PMS) presumably attributed to enhanced electron transfer between TMs, but the existing model cannot fully explain the efficient TM redox cycling. Here, we discover a critical role of TM?O covalency in governing the intrinsic catalytic activity of Co_3?xMn_xO₄ spinel oxides. Experimental and theoretical analysis reveals that the Co sites significantly raises the Mn valence and enlarges Mn?O covalency in octahedral configuration, thereby lowering the charge transfer energy to favor Mn_Oh–PMS interaction. With appropriate Mn^IV/Mn^III ratio to balance PMS adsorption and Mn^IV reduction, the Co_1.1Mn_1.9O₄ exhibits remarkable catalytic activities for PMS activation and pollutant degradation, outperforming all the reported TM spinel oxides. The improved understandings on the origins of spinel oxides activity for PMS activation may inspire the development of more active and robust metal oxide catalysts.     

天然高分子负载双金属催化剂催化硝基苯还原羰化反应

天然生物高分子材料-壳聚糖(简写为CS)负载催化刑：Si02—CS—PdCl2，利用Pd-Ni双金属协同效应和高分子载体对催化活性物种的保护，在催化硝基苯的还原碳化反应中表现出了较高的催化活性和选择性．并且尝试了催化刑的重复使用．     

双金属板拉延成形的有限元分析

双金属板拉延成形同时包含几何非线性、塑性、接触、摩擦以及双金属板中组元金属力学性能差异等多种复杂因素。组元金属之间不均匀的塑性变形是导致组元金属在拉延过程中产生缺陷的主要根源。本文基于刚塑性有限元方法，对双金属板的拉延成形过程进行了有限元分析，揭示了组元金属的等效应变分布规律和厚向应变分布规律。本文的研究方法和结论可以为工艺参数的合理选择和优化提供参考和依据。