Ionization of Porous Hypercrosslinked Polymers for Catalyzing Room-Temperature CO2 Reduction via Formamides Synthesis

Catalysis Letters - Porous materials with heterogeneous nature occupy a pivotal position in the chemical industry. This work described a facile pre- and post-synthetic approach to modify porous...     

Photo-Chemically-Deposited and Industrial Cu/ZnO/Al2O3 Catalyst Material Surface Structures During CO2 Hydrogenation to Methanol: EXAFS,XANES and XPS Analyses of Phases After Oxidation,Reduction, and Reaction

Catalysis Letters - Industrial Cu/ZnO/Al2O3 or novel rate catalysts, prepared with a photochemical deposition method, were studied under functional CH3OH synthesis conditions at the set temperature...     

Metallic Nanoparticles in Heterogeneous Catalysis

Catalysis Letters - Heterogeneous catalysis is a chemical process achieved at solid–gas or solid–liquid interfaces. Many factors including the particle size, shape and metal-support...     

Thermal cross-linking and anti-meltdrop properties of copolyester containing phosphorus/magnesium salt composites by in situ polymerization

Polyester is widely used in household products because of its good mechanical properties and wears resistance, but polyester is easy to ignite and inclined to produce droplet, so its application range is limited. The cross-linkable magnesium hydroxide nanoparticles were incorporated into flame-retardant polyester, which enables the phosphorus-containing copolyester with thermal cross-linking and anti-meltdrop properties. The nanoparticles were achieved by in situ polymerization and acted as a nucleating agent for improving the crystalline properties of the copolyester. Furthermore, the nanoparticles also enhanced anti-meltdrop properties and reduced the heat and gas release during the combustion process of the copolyester. The maximum heat release rate and total smoke release reduced by 39.8% and 74.4% compared with pure polyester. Specifically, the combustion products of the nanoparticles and phosphorus flame retardant could act a barrier role by covering the carbon layer to isolate air and heat, thereby resulting in excellent anti-meltdrop properties. The simple modification method reported here realizes the collaborative modification of flame retardant and anti-meltdrop properties of phosphorous flame-retardant copolyesters by thermal cross-linking.     

关于超耐候性BA01—02钛白粉的研制

采用高温淬火方法制备了Ｔｃ在２７．４Ｋ至９２．４Ｋ之间的一组不同氧含量的ＰＭＰ（粉末熔融工艺）法ＹＢＣＯ超导体。通过对这些超导体样品的磁滞回线及不可逆线的研究发现，随着氧空位的增加，超导体的磁通钉扎力减小     

Effect of pulse parameters on microstructure of joint in laser beam welding for SiC_p/6063 composite

1　INTRODUCTIONSiC particlesreinforcedcomposites ,thankstotheirlowcostsandhighlevelofstructuralproperties ,areshowingtheirpotentialincivilandmilitaryappli cation .SiC particlesreinforcedaluminummatrixcomposites wideapplicationinaerospaceandautomo tiveareattributedtotheirperformanceofhighspecif icstrength ,highspecificstiffness ,highelasticmodu lusandexcellentwearresistance .Thecoefficientofthermalexpansionandthermalconductivitycanberegulatedbychangingthecontentandsizeofrein forcingparticl…     

无线传感器网络移动Sink网关系统的设计与实现*

针对无线传感器网络传统Sink网关的不足,提出了一种基于PDA的移动Sink网关系统的设计与实现方案,对其设计目标、体系结构和工作原理进行了论述,重点讨论了PDA与Sink节点之间的连接,PDA与Sink节点、PDA与GPS接收机及PDA与控制终端之间通信的一些关键技术.     

基于DSP+CPLD的车牌实时识别系统的设计

传统的基于微机的车牌识别系统的方案,使得评价识别效果的识别速率和识别成功率两个重要指标相互冲突.为了解决这个问题,很多文章提出了改进算法来调和识别算法的计算量和识别的成功率,但却没有考虑识别系统的成本问题.提出了一个基于DSP CPLD的硬件识别平台,可以大大提高各种识别算法的适应性和降低系统成本.     

Differential Subcellular Distribution of Cytokinins: How Does Membrane Transport Fit into the Big Picture?

Cytokinins are a class of phytohormones, signalling molecules specific to plants. They act as regulators of diverse physiological processes in complex signalling pathways. It is necessary for plants to continuously regulate cytokinin distribution among different organs, tissues, cells, and compartments. Such regulatory mechanisms include cytokinin biosynthesis, metabolic conversions and degradation, as well as cytokinin membrane transport. In our review, we aim to provide a thorough picture of the latter. We begin by summarizing cytokinin structures and physicochemical properties. Then, we revise the elementary thermodynamic and kinetic aspects of cytokinin membrane transport. Next, we review which membrane-bound carrier proteins and protein families recognize cytokinins as their substrates. Namely, we discuss the families of “equilibrative nucleoside transporters” and “purine permeases”, which translocate diverse purine-related compounds, and proteins AtPUP14, AtABCG14, AtAZG1, and AtAZG2, which are specific to cytokinins. We also address long-distance cytokinin transport. Putting all these pieces together, we finally discuss cytokinin distribution as a net result of these processes, diverse in their physicochemical nature but acting together to promote plant fitness.