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991.
We report two synthetic systems, Cu(Bpy)2+ and Cu(Phen)2+, for catalytic hydrogenation of steroidal haloalkenes in the presence of hydrazine and air. Thesestudies demonstrated that the selective hydrogenation is faster for the 1,10‐phenanthroline–Cu(II) system because forming more stable copper complex are formed, leaving fewer free copper ions in solution. Evidence also supports that the catalytic power of Cu(II) ions can be tuned moderately through the addition of bidentate ligand, Bpy or Phen. 相似文献
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994.
Strongly Phosphorescent Neutral Rhenium(I) Isocyanoborato Complexes: Synthesis,Characterization, and Photophysical,Electrochemical, and Computational Studies
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Wing‐Kin Chu Xi‐Guang Wei Dr. Shek‐Man Yiu Dr. Chi‐Chiu Ko Dr. Kai‐Chung Lau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2603-2612
A new series of neutral isocyanoborato rhenium(I) diimine complexes [Re(CO)3(N^N)(CNBR3)], where N^N=bpy, 4,4′‐Me2bpy, phen, 4,7‐Me2phen, 2,9‐Me2phen, 3,4,7,8‐Me4phen; R=C6F5, C6H5, Cl, 4‐ClC6H4, 3,5‐(CF3)2C6H3, with various isocyanoborate and diimine ligands of diverse electronic and steric nature have been synthesized and characterized. The X‐ray crystal structures of six complexes have also been determined. These complexes displayed intense bluish green to yellow phosphorescence at room temperature in dichloromethane solution. The photophysical and electrochemical properties of these complexes had been investigated. To elucidate the electronic structures and transitions of these complexes, DFT and TD‐DFT calculations have been performed, which revealed that the lowest‐energy electronic transition associated with these complexes originates from a mixture of MLCT [dπ(Re)→π*(N^N)] and LLCT [π(CNBR3)→π*(N^N)] transitions. 相似文献
995.
Fu Yuwei Luo Santu Li Xingdi Chen Chi Wang Chuang Zhang Zaiqin Liu Dingxin 《Plasma Chemistry and Plasma Processing》2022,42(6):1265-1278
Plasma Chemistry and Plasma Processing - C5F10O-insulated environmental-friendly power equipment has great potential to be used in the near future to reduce greenhouse effect. During maintenance,... 相似文献
996.
Aseries of Ni catalysts supported on alumina with different Ce contents(1.0%-6.0%, mass fraction) was prepared by the impregnation method and used for dry reforming of methane(DRM) at a relatively low temperature of 650 oC. The promotion effect of Ce with different loading amounts on the physicochemical properties of the catalysts was systematically characterized by transmission electron microscopy(TEM), X-ray diffraction(XRD), N2 adsorption-desorption, thermo elemental IRIS Intrepid inductively coupled plasma atomic emission spectrometer (ICP-AES), UV-visible diffuse reflectance spectroscopy(UV-Vis DRS), Fourier transformation infrared(FTIR) spectra, H2-temperature programmed reduction(H2-TPR) analysis, H2-temperature programmed desorption(H2-TPD), and the X-ray photoelectron spectroscopy(XPS) techniques. The results indicate that all the catalysts mainly exist in the NiAl2O4 phase after being calcined at 750 oC with small Ni particle sizes due to the strong metal-support interaction derived from the reduction of the NiAl2O4 phase. The Ce-promoted catalysts show better catalytic performance as well as the resistance against sintering of Ni particles and deposition of carbon compared to the Ni/Al2O3 catalyst. The Ni-6Ce/Al2O3 exhibits the best catalytic stability and coke resistance among the four catalysts studied, which is due to its small Ni nanoparticles sizes, excellent reducibility as well as high amount of active oxygen species. In a 400 h stability test for DRM reaction at 650 oC, Ni-6Ce/Al2O3 exhibits less coke deposition and small growth of Ni nanoparticles. This work provides a simple way to preparing the Ni-Ce/Al2O3 catalyst with enhanced catalytic performance in DRM. The Ni-6Ce/Al2O3 catalyst has great potential for industrial application due to its anti-sintering ability and resistance to carbon deposition. 相似文献
997.
Yuanqing Wei Ting Liu Binru Zheng Yilin Song Shengsong Wang Mojuan Zheng Yanling Xu Yumei Chi Ming Zhao Jin-ao Duan Shuying Han Rui Liu 《Journal of separation science》2022,45(4):812-823
A new strategy combined gold-coated magnetic nanocomposites assisted enrichment with mass spectrometry was developed for the characterization of disulfide bond-contained proteins from Chinese cobra (Naja atra) venom. In this work, core-shell nanocomposites were synthesized by the seed-mediated growth method and used for the enrichment of snake venom proteins containing disulfide bonds. A total of 3545 tryptic digested peptides derived from 96 venom proteins in Naja atra venom were identified. The venom proteins comprised 14 toxin families including three-finger toxins, phospholipase A2, snake venom metalloproteinase, cobra venom factor, and so forth. Extra 16 venom proteins were detected exclusively in the nanocomposites set, among which 11 venom proteins were from the three-finger toxins family. In the present study, the proposed simple and efficient protocol replaced the tedious and laborious technologies commonly used for pre-separating crude snake venom, suggesting widely implementation in low-abundance or trace disulfide bond-contained proteins or peptides characterization. 相似文献
998.
Wenjing Li Caihong Li Kang Sun Chenglin Chi Zongchao Li Lixiao Xu Yan Zhao Rongxia Liu 《Journal of separation science》2022,45(14):2734-2745
Comprehensive ingredient research is of great significance for understanding the effective material basis of herbal medicines, but due to the diversity and complexity of their phytochemicals, such research is challenging. Here, a multifaceted strategy was proposed to analyze and identify the composition of HuangLian JieDu Decoction based on offline two-dimensional liquid chromatography combined with ultraviolet detection and high-resolution mass spectrometry. Multiple components were separated by two-dimensional liquid chromatography, which consisted of hydrophilic interaction chromatography and reversed-phase liquid chromatography, and then further characterized by high-resolution mass spectrometry with a full mass spectrometry/precursor ion list/data-dependent secondary scan data acquisition method. For data processing, database screening and molecular networking were used to identify the components in HuangLian JieDu Decoction. The offline two-dimensional liquid chromatography combined with ultraviolet detection and a high-resolution mass spectrometry system showed good orthogonality of 76.35% and a high peak capacity of 5175, effectively separating multiple components. Finally, 527 compounds, including 164 alkaloids, 133 terpenoids, 88 flavonoids, 60 phenylpropanoids, 38 organic acids, and 44 other compounds, were characterized. This integrated approach is suitable for the comprehensive characterization of herbal medicines and other complex chemical systems. 相似文献
999.
随着科技发展, 如何解决大视场和高分辨率之间的矛盾成为了众多科技人员的研究重心之一, 本文提出了双小凹成像系统的概念, 在传统仿真人眼的单小凹成像系统的基础上, 通过引入反射式液晶空间光调制器对光学系统进行两个视场内波像差的调制, 改善对应的像差, 从而实现了大视场内低分辨率成像的条件下, 在两个特定的视场内满足高分辨率成像, 因此可解决大视场和高分辨率的矛盾.本文通过设计一个参考波长为587 nm, 视场为60° (即± 30°),F数为F/8, 焦距为60 mm的双小凹光学成像系统, 并利用CODE V软件模拟仿真实现了5°和17°双视场高分辨率成像, 其余视场低分辨率成像, 并以32×32的采样分辨率计算了该系统的衍射效率, 验证了设计方法的科学性和准确性. 相似文献
1000.