具有转向点曲线的二阶椭圆型方程边值问题的奇摄动

本文讨论了;较一般的一类具有转向点曲线的奇摄动椭圆型方程的边值问题,利用多重尺度法和比较定理,研究了边值问题解的一致有效渐近近似式。     

Dichloro(2,2′‐diamino‐4,4′‐bi‐1,3‐thiazole‐N3,N3′)copper(II)

The title complex, [CuCl₂(C₆H₆N₄S₂)], has a flattened tetrahedral coordination. The Cu^II atom is located on a twofold rotation axis and is coordinated by two N atoms from a chelating 2,2′‐di­amino‐4,4′‐bi‐1,3‐thia­zole ligand and by two Cl atoms. Intramolecular hydrogen bonding exists between the amino groups of the 2,2′‐di­amino‐4,4′‐bi‐1,3‐thia­zole ligand and the Cl atoms. The intermolecular separation of 3.425 (1) Å between parallel bi­thia­zole rings suggests there is a π–π interaction between them.     

Non-Invasive Detection of Anti-Inflammatory Bioactivity and Key Chemical Indicators of the Commercial Lanqin Oral Solution by Near Infrared Spectroscopy

Quality control methods of current traditional Chinese medicine (TCM) preparation is time-consuming and difficult to assess in terms of overall efficiency of the drug. A non-destructive rapid near-infrared spectroscopy detection system for key chemical components and biological activity of Lanqin oral solution (LOS), one of the best-selling TCM formulations, was established for comprehensive quality evaluation. Near infrared spectral scanning was carried out on 101 batches of commercial LOS under the penetrated vial state and traditional state. RAW 264.7 cells were cultured to detect the anti-inflammatory ability of LOS, and the reference concentrations of epigoitrin, geniposide, and baicalin were obtained by HPLC. The quantitative models were optimized by three kinds of variable selection methods. The correlation coefficients of prediction value of the models were greater than 0.94. The system also passed the external validation. The performance of the non-invasive models was similar to the traditional models. The established non-destructive system can be applied to the rapid quality inspection of LOS to avoid unqualified drugs from entering the market and ensure drug effectiveness. The biological activity index of LOS was introduced and predicted by NIRs for the first time, which provides a new idea about the quality control of TCM formulations.     

Nb掺杂调控CoSeS多级纳米结构用于增强析氢反应

电催化析氢(HER)是清洁制氢的一种有效途径,对于氢经济和氢能产业的发展具有重要意义.金属掺杂是提高电催化剂本征活性的有效方法,导电基底的采用也有利于电荷传输和催化性能的整体提高.尽管已有关于硒化物作为HER催化剂的相关报道,但是合成条件有限、导电性、本征活性的影响,其电催化性能仍有提升的空间.此外,在酸性电解液中的腐...     

珊瑚状Ni2P修饰新型四足状Cd0.9Zn0.1SZB/WZ同质结光催化剂的高效可见光光催化产氢

随着社会发展,传统化石能源消耗加剧,人类迫切需要开发新型的清洁能源.半导体光催化分解水产氢是一种非常具有潜力解决能源危机的清洁技术.目前,金属硫化物半导体有着合适的能带结构和高效的光催化产氢能力而得到了广泛的研究.通常,为了提高光催化剂产氢性能,添加贵金属助催化剂是一个行之有效的方法.但是贵金属昂贵的价格限制了其大规模...     

Metal-Carboxyl Helical Chain Secondary Units Supported Ion-Exchangeable Anionic Uranyl–Organic Framework

As a less explored avenue, actinide-based metal-organic frameworks (MOFs) are worth studying for the particularity of actinide nodes in coordination behaviour and assembly modes. In this work, an azobenzenetetracarboxylate-based anionic MOF supported by uranyl–carboxyl helical chain units was synthesized, incorporating linear uranyl as the metal centre. This kind of helical chain-type building unit is reported for the first time in uranyl-based MOFs. Structural analysis reveals that the formation of helical chain secondary units can be attributed to restricted equatorial coordination of rigid flat azobenzene ligand to uranyl centres. Meanwhile, this newly-synthesized anionic material has been used to remove Eu³⁺ ions, as a non-radioactive surrogate of Am³⁺ ion, through an ion-exchange process with [(CH₃)₂NH₂]⁺ ions in its open channels, as evidenced by a combination of ¹H NMR spectroscopy, EDS and PXRD.     

Thermal cycling effect on the kinetics of glass transition and crystallization of a Zr-based bulk metallic glass

Journal of Thermal Analysis and Calorimetry - This work presents the convective heat transfer and friction loss characteristics of novel functionalized graphene-based and metal oxide nanofluids....     

Computational Study of spx(x=1–3)-Hybridized Be−Be Bonds Stabilized by Amidinate Ligands

Complexes containing odd-electron Be−Be bonds are still rare until now. Hereby, a series of neutral di-beryllium amidinate complexes containing a Be−Be bond were explored theoretically. The complexes with direct chelation with the Be₂ dimer by the bidentate amidinate (AMD) ligands are always corresponding to their global minimum structures. The detailed bonding analyses reveal that the localized electrons of the Be−Be fragment can be adjusted by the amount of AMD ligands because each AMD ligand only takes one electron from the Be₂ fragment. Meanwhile, the hybridization of the central Be atom also changes as the number of AMD ligands increases. In particular, the sp³-hybridized single-electron Be−Be bond is firstly identified in the tri-AMD-ligands-chelated neutral D_3h- Be₂(AMD)₃ complex, which also possesses the higher stability compared to its monoanionic D_3h- Be₂(AMD)₃ ⁻ and monocationic C₃- Be₂(AMD)₃ ⁺ analogues. Importantly, our study provides a new approach to obtain a neutral odd-electron Be−Be bond, namely by the use of radical ligands through side-on chelation.