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排序方式: 共有654条查询结果,搜索用时 234 毫秒
141.
Dr. Quentin Lefebvre Dr. Riccardo Porta Dr. Anthony Millet Dr. Jiaqi Jia Prof. Dr. Magnus Rueping 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(6):1363-1367
Owing to their wide range of biological properties, γ-aminobutyric acid derivatives (GABA) have been extensively studied and found noteworthy industrial applications. However, atom-economical and efficient processes for their production are scarce and would greatly benefit from further investigations. Herein, we demonstrate that an iridium-based photocatalyst promotes the direct reductive cross-coupling of imines with olefins upon irradiation with visible light to give GABA derivatives in good yields and selectivities. We also stress the enabling triple role of tributylamine additive in this process, discuss the advantages of strategies based on proton-coupled electron transfer (PCET) and demonstrate the scale-up of this reaction in continuous flow. 相似文献
142.
一类奇摄动非线性方程的激波解 总被引:2,自引:0,他引:2
利用匹配条件讨论一类奇摄动非线性方程激波解.得出了对应的激波解与边界条件的关系. 相似文献
143.
讨论了一类具有超抛物型方程的反应扩散问题.首先,证明了比较定理.其次,构造了形式渐近解.然后,利用微分不等式方法,研究了问题解的存在、唯一性和渐近性态.最后得到了原问题解的渐近展开式. 相似文献
144.
Zhaolai Huang Jiaqi Li Mengxiao Zhang Weilin Feng Chuanjie Fang Liping Zhu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2298-2308
Polymers of intrinsic microporosity (PIMs) are promising materials for membrane separation because their special rigid and contorted structures contribute to high permeability. However, their chain rearrangement to fill excessive free volume makes the permeability stability a tough challenge. In this work, we report on a new use of rutile nano-TiO2 to mitigate the physical aging of PIM-1 (a typical PIM) nanofilms for stable permeability by mixing matrix. It was shown that the PIM-1 membrane incorporated with nano-TiO2 displayed remarkably higher aging resistance with a lower swelling degree in long-term ethanol soaking, having more stable ethanol permeance with only a 5% decrease after 35 days, lower than 25% of the pure one. The mechanism of anti-aging was revealed by molecular simulation, thermal, tensile mechanical, and dynamic mechanical analysis. It was found that nano-TiO2 had good compatibility with PIM-1 due to strong coordination interaction, making its uniform dispersion in polymer. Additional solvent permeation channels were also created to increase solvent permeance without compromising solute rejection. Due to the reliable interaction of nano-TiO2, which makes particles serve as physical crosslinking points, the movement of PIM-1 chains was limited partially to mitigate aging, enabling PIM-1-based membranes to have robust solvent permeation. 相似文献
145.
Sheng Xianxian Xu Zhiqiang Liu Yulong Wang Peng Dong Jiaqi Lu Zhanpeng Shan Ali Lyu Shuguang 《Research on Chemical Intermediates》2022,48(4):1645-1663
Research on Chemical Intermediates - In this study, the removal performance and degradation mechanisms of fluoranthene (FLT) in sodium percarbonate (SPC) activated by Fe(II) system were... 相似文献
146.
Carbon has three hybridization forms of sp−, sp2− and sp3−, and the combination of different forms can obtain different kinds of carbon allotropes, such as diamond, carbon nanotubes, fullerene, graphynes (GYs) and graphdiyne (GDY). Among them, the GDY molecule is a single-layer two-dimensional (2D) planar structure material with highly π-conjugation formed by sp− and sp2− hybridization. GDY has a carbon atom ring composed of benzene ring and acetylene, which makes GDY have a uniformly distributed pore structure. In addition, GDY planar material have some slight wrinkles, which makes GDY have better self-stability than other 2D planar materials. The excellent properties of GDY make it attract the attention of researchers. Therefore, GDY is widely used in chemical catalysis, electronics, communications, clean energy and composite materials. This paper summarizes the recent progress of GDY research, including structure, preparation, properties and application of GDY in the field of catalysts. 相似文献
147.
BOUNDARY VALUE PROBLEMS TO A CLASS OF SINGULARLY PERTURBED NONLINEAR SYSTEM WITH TURNING POINTS 总被引:1,自引:0,他引:1
ConsidertheboundaryvalueproblemtothesingularlyperturbednonlinearsystemintheformofwhereEisasmallpositiveparameter,y=(yi,'..)y.),f=(fi,...)fn),A=(Al,'',A.)andB=(BI,sn).MohasdiscussedtheseDroblemsundervarioussituationsusingthemethodofdifferentialinequalities[1--'].Inthispaperweconsiderthecaseoffi.:(0,y,y')=0anduseaclassofnewboundarylayerfunctions.TheoremAssumethat(a)fi(x,y,z)Hfi(x,yi,'',yn,if)''jz.)eC'{xE[~l,1],yie[di,ei],ifER}andtherearepositivenondecreasingcontinuousfunctionsif,i=1,2,'… 相似文献
148.
Pu Wenjing Xi Xuyao Tao Pengyu Shi Bo Wen Jiaqi Lu Wei 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(8):3295-3301
Journal of Radioanalytical and Nuclear Chemistry - Polysilane is expected to be a highly efficient and environmentally friendly liquid scintillator, for its unique fluorescence performance based on... 相似文献
149.
通过金属有机物分解法(MOD)协同光电化学沉积法, 将p型氧化物半导体CuBi2O4沉积在BiVO4纳米薄膜上, 形成包覆性异质结结构, 制备了一种新型p-n异质结光阳极n-BiVO4/p-CuBi2O4, 用于太阳能光电化学(Photoelectrochemical, PEC)水分解. 研究结果表明, 在1.23 V(vs. RHE)电势下, BiVO4/CuBi2O4 异质结光阳极表现出优良的PEC水氧化性能, 光电流密度达到2.8 mA/cm2, 负载磷酸钴(Co-Pi)的BiVO4/CuBi2O4/Co-Pi光电极, 光电流密度达到4.45 mA/cm2, 分别为BiVO4电极光电流密度的3.1倍和4.9倍. X射线衍射(XRD)、 紫外-可见吸收光谱(UV-Vis)、 电化学阻抗谱(EIS)和能级结构图等结果也证实, BiVO4/CuBi2O4和BiVO4/CuBi2O4/Co-Pi复合电极材料在内建电场和能带弯曲作用下, 光吸收特性增强, 载流子界面转移电阻减小, 具有良好的光电化学性能与稳定性. 相似文献
150.
Tang Qin Xu Fei Zhang Chuanli Li Chang Liu Feng Shen Ming Liu Xun Lin Jiaqi Zhu Limin Lin Tingting Sun Di 《Journal of inclusion phenomena and macrocyclic chemistry》2022,102(9-10):735-742
Journal of Inclusion Phenomena and Macrocyclic Chemistry - Indocyanine green (ICG) angiography is of great importance for ophthalmic diagnostic applications and is mainly used to check for... 相似文献