Thermal design and simulation of space-borne membrane antenna

Thermal deformation of space-borne radar antenna caused by dramatic changes in orbit thermal environment has a serious effect on image qualities. In this paper, the NX TMG module was used to simulate the orbit thermal environment of the antenna, and a thermal control design was proposed. The thermal control structure consists of three layers; the top is a radiator with high emissivity surface, the middle is a multi-layer insulation, and the bottom is a highly reflective layer. The simulation results show that the thermal design could reduce the temperature gradient from 238.1 to 31.4 °C effectively.

     

Gallium Oxide Nanorods: Novel,Template‐Free Synthesis and High Catalytic Activity in Epoxidation Reactions

Gallium oxide nanorods with unprecedented small dimensions (20–80 nm length and 3–5 nm width) were prepared using a novel, template‐free synthesis method. This nanomaterial is an excellent heterogeneous catalyst for the sustainable epoxidation of alkenes with H₂O₂, rivaling the industrial benchmark microporous titanosilicate TS‐1 with linear alkenes and being much superior with bulkier substrates. A thorough characterization study elucidated the correlation between the physicochemical properties of the gallium oxide nanorods and their catalytic performance, and underlined the importance of the nanorod morphology for generating a material with high specific surface area and a high number of accessible acid sites.     

Homogeneous and stable carbon nanotube dispersion assisted by cellulose in NaOH/thiourea aqueous solution

Cellulose - Carbon nanotubes (CNTs) have been proposed as next-generation lightweight structural materials, yet their application is facing challenges due to the poor dispersity in most solvents,...     

TDDFT investigation on electronically excited-state hydrogen-bonding properties and ESIPT mechanism for the 2-(1H-imidazol-2-yl)-phenol compound

Structural Chemistry - In this work, DFT and TDDFT approaches have been executed to make a detailed exploration about the excited state luminescent properties as well as excited state...     

(Ti/ZnO)N成分调制纳米多层膜的结构与透光导电性研究

采用射频(RF)和单极中频直流脉冲磁控溅射方法,在玻璃基板上制备了(Ti/ZnO)N成分调制纳米多层膜,并研究了调制周期数对其结构及透光导电性能的影响.通过X射线衍射、拉曼光谱、原子力显微镜、紫外可见吸收光谱以及霍尔效应测试结果表明:(Ti/ZnO)N成分调制纳米多层膜以(002)取向的纤锌矿型ZnO结构为主,具有明确...     

Incorporating Transition-Metal Phosphides Into Metal-Organic Frameworks for Enhanced Photocatalysis

Metal-organic frameworks (MOFs) have been shown to be an excellent platform in photocatalysis. However, to suppress electron–hole recombination, a Pt cocatalyst is usually inevitable, especially in photocatalytic H₂ production, which greatly limits practical application. Herein, for the first time, monodisperse, small-size, and noble-metal-free transitional-metal phosphides (TMPs; for example, Ni₂P, Ni₁₂P₅), are incorporated into a representative MOF, UiO-66-NH₂, for photocatalytic H₂ production. Compared with the parent MOF and their physical mixture, both TMPs@MOF composites display significantly improved H₂ production rates. Thermodynamic and kinetic studies reveal that TMPs, behaving similar ability to Pt, greatly accelerate the linker-to-cluster charge transfer, promote charge separation, and reduce the activation energy of H₂ production. Significantly, the results indicate that Pt is thermodynamically favorable, yet Ni₂P is kinetically preferred for H₂ production, accounting for the higher activity of Ni₂P@UiO-66-NH₂ than Pt@UiO-66-NH₂.     

Real-time imaging of cell-surface proteins with antibody-based fluorogenic probes

Cell-surface proteins, working as key agents in various diseases, are the targets for around 66% of approved human drugs. A general strategy to selectively detect these proteins in a real-time manner is expected to facilitate the development of new drugs and medical diagnoses. Although brilliant successes were attained using small-molecule probes, they could cover a narrow range of targets due to the lack of suitable ligands and some of them suffer from selectivity issues. We report herein an antibody-based fluorogenic probe prepared via a two-step chemical modification under physiological conditions, to fulfill the selective recognition and wash-free imaging of membrane proteins, establishing a modular strategy with broad implications for biochemical research and for therapeutics.

A modular strategy to convert commercially available antibodies into fluorogenic probes has been developed, enabling selective recognition and wash-free imaging of endogenous membrane proteins.      

2-氰基苄基诱导的葡萄糖醛酸β糖苷键立体选择性

以2,3-O-(2-氰基苄基)-4-O-氯乙酰基-β-对甲基苯基-D-葡萄糖醛酸硫苷等7个单糖模块作为糖基供体, 以甲醇等醇类化合物作为糖基受体, 分别在二氯甲烷和甲苯溶剂中进行了糖基化反应, 研究了葡萄糖醛酸C2位引入2-氰基苄基(BCN)以及溶剂效应对糖苷键α/β选择性的影响. 通过对糖基产物的 ¹H NMR, ¹³C NMR和HSQC等谱图分析发现, BCN可以有效提高糖苷键的β选择性, 其中部分糖基化产物的糖苷键α/β比例最高可达1/50. 为磺达肝癸钠分子中葡萄糖醛酸的β糖苷键的构建方法做出了初步探索.     

Synthesis and Antibacterial Activity of 8-Substituted Phenyl-1-pyridin-3-yl-5H-bis[1,2,4]triazolo[3,4-b;4′,3′-d][1,3,4] thiadiazines

1,2,4-Triazole derivatives, such as 1, 2, 4-triazolo[3, 4-b]thiadiazoles and 1, 2, 4- triazolo [3,4-b]thiadiazolines, as potent antibacterial agents have been widely investigated1-4. Chemically, their structures mainly focus on bi-fused heterocycles, but tri-fused derivatives have not been reported. In continuing our previous works5-8 on finding better antibacterial agents, we herein reported the synthesis and pharmacological evaluation for completely new class of compounds 4a~e with antibacte…     

An adapted isotope dilution 1H–13C heteronuclear single-quantum correlation (ID-HSQC) for rapid and accurate quantification of endogenous and exogenous plasma glucose

Analytical and Bioanalytical Chemistry - A wide variety of methods, such as enzymatic methods, LC-MS, and LC-MS/MS, are currently available for the concentration determination of plasma glucose in...