Preparation of styrene–divinyl benzene copolymer-supported platinum complexes and their catalytic properties in hydrosilylation

A new type of catalyst for the hydrosilylation of unsaturated monomers with dichloromethylsilane (DCMS) was prepared, which consisted of thiolmethylene-substituted styrene–divinyl benzene copolymer and platinum. When using DCMS as a hydrosilylation agent, these catalysts showed a high activity in the hydrosilylation of vinyl and acetylene monomers as styrene, alkyl vinyl silanes, acetylene, phenyl acetylene, butyl acrylate. The activities of catalysts were not significantly reduced even after 20 reuse cycles.     

The Effect of Different Inorganic Salts on the Growth Rate of NaCl Crystallized from Sea Water

A comprehensive experimental study on the effect of fourteen different inorganic salts on the growth rate of NaCl single crystals is presented. The fourteen different inorganic salts are chosen as they are present in Chinese sea water. The impurity content of each salt has been varied according to its presence in the natural sea water. The impurities are differentiated in groups related to their effect on the growth rate of NaCl. The examined impurities are: MgCl₂ · 6 H₂O, KCl, SrCl₂, NaBr, Nal, NaF, Na₂SO₄, NaBO₂ · 4 H₂O, Na₂CO₃, Na₂SiO₃ · 9 H₂O, ZnSO₄, CuSO₄ · 5 H₂O, PbCl₂, and K₄Fe(CN)₆.     

质量管理八项原则与企业整体化管理

阐述质量管理八项原则的基本内涵和相互关系,它是企业推进质量管理和贯彻ISO9000:2000系列标准必须遵循的基本准则,同时为企业整体化管理提供一条正确的思路.     

A Double-Site Chemodosimeter for Selective Fluorescence Detection of a Nerve Agent Mimic

A novel two-site chemodosimeter (SWJT-4) based on fluorescein skeleton to detect diethyl chlorophosphate (DCP) was designed and synthesized. It is a turn-on fluorescent probe for DCP with good selectivity and obvious color change in aqueous solution. Interestingly, the two oxime groups of SWJT-4 as dual response sites initiated different reactions with DCP to form a cyano group and an isoxazole ring, respectively. The corresponding mechanism was confirmed by ¹H NMR, MS and DFT calculation. Moreover, SWJT-4 could be used as a fluorescent test paper to detect DCP vapor.     

Magnetron sputtering deposition of silicon nitride on polyimide separator for high-temperature lithium-ion batteries

To date,lithium-ion batteries are becoming increasingly significant in the application of portable devices and electrical vehicles,and revolutionary progress in theoretical research and industrial application has been achieved.However,the commercial polyolefin separators with unsatisfying electrolytes affinity and poor thermal stability have extremely restricted the further application of lithium-ion batteries,especially in the high-temperature fields.In this work,magnetron sputtering deposition technique is employed to modify the commercial polyimide separator by coating silicon nitride on both sides.Magnetron sputtering deposition modified polyimide(MSD-PI)composite separator shows high thermal stability and ionic conductivity.More importantly,compared with the cells using Celgard separator,the cells with MSD-PI separator exhibit superior electrochemical performance,especially long-term cycle performance under high temperature environment,owing to the high thermal conductivity of surface Si3 N4 particles.Hence,lithium-ion batteries with MSD-PI separator are capable of improving thermal safety and capacity retention,which demonstrates that magnetron sputtering deposition technique could be regarded as a promising strategy to develop advanced organic/inorganic composite separators for high-temperature lithium-ion batteries.     

Unraveling the condensation reactions of heterometallic {BiNb_4} moieties into hybrid Bi_xNb_y-oxo clusters with mass spectrometry

The most effective methodologies for the construction of polynuclear complexes usually take advantage of preorganized building blocks.Herein,we successfully developed a new versatile heterometallic{BiNb₄}moiety,which can be applied for the assembly of less explored organic-inorganic hybrid polyoxoniobates.Through controlled condensation reactions,three{BiNb₄}moieties can be assembled into a pair of isomeric Bi₃Nb₁₈clusters at different temperatures;whilst four{BiNb₄}moieties can be combined into two unique Bi₄Nb₁₆and Bi₄Nb₁₈tetramers in different solvents.Interestingly,we have used mass spectrometry to probe the above condensation reactions,which clearly confirmed a stepwise bottom-up assembly process by capturing the presence of bismuth subsalicylate precursors,salicylate coordinated intermediates,Nb incorporated{BiNb₄}moieties and the final Bi_xNb_y-oxo clusters,respectively.Moreover,the packing modes of the{BiNb₄}units induce different solution behaviors,and the{BiNb₄}units in Bi4Nb16can be recombined by post-synthetic recrystallization in acetonitrile to produce a new tetramer Bi₄Nb₁₈-R.Therefore,this work provides not only a useful{BiNb₄}building unit but also the mechanism for their condensation,both of which will promote the future development of metal-oxo clusters.     

Fixed-time SOSM controller design with output constraint

Nonlinear Dynamics - In this paper, a novel fixed-time second-order sliding mode (SOSM) controller has been developed for a class of nonlinear systems with output constraints. Based on the output...     

基于改进云推理算法的塔架结构损伤识别

为了解决塔架结构的损伤识别问题,提出了基于应变能和改进云推理算法的损伤识别方法。首先描述了云模型的基本理论和数字特征,并给出了模态应变能的基本公式;然后分析了X条件云发生器和Y条件云发生器的基本算法和运行步骤,借助灰云模型建立相应的前件云和后件云规则,考虑了测量噪声的影响,利用云发生器生成多组云滴,并利用多模式下云滴的确定度和生成值构建了基本云推理算法及其损伤识别指标。基本云推理算法中常会产生不均匀发散的云滴,从而使计算结果产生一定的偏差,为了降低云滴发散产生的偏差影响,提出了基于损伤模式数量加权的云推理改进策略。计算结果表明:云推理算法可以较好地应用于塔架结构的损伤识别,其识别结果明显优于传统的应变能耗散率指标方法;而改进云推理算法进一步提高了识别的精度,优于基本云推理算法。     

Ag@CH3NH3PbI3等离激元效应增强钙钛矿太阳能电池性能的数值研究

由于银纳米粒子结构的表面等离激元共振特性对有机无机卤化物钙钛矿的新型太阳能电池性能有一定影响,利用comsol mutiphysics多物理场仿真软件对Ag@CH3 NH3 PbI3纳米粒子等离激元效应增强钙钛矿太阳能薄膜电池性能进行研究,对粒子半径和粒子间距对于能量的影响进行了计算;对光敏层能量增强的机理进行了解释;并对电场分布进行了详细说明.依据实验数据,给出优化后的银纳米粒子阵列和钙钛矿光敏层的厚度以及强度,为实验制备高效稳定的钙钛矿太阳能电池提供理论指导.     

雷达阵地选择方案的多层次灰评价

根据雷达兵部队阵地选择的基本要求,分析了影响雷达效能的制约因素,给出了阵地选择评价指标体系的结构模型,最后通过多层次灰度决策评价给出了雷达阵地选择的应用算例。