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991.
Naghmeh Esfandiary Farzane Pazoki Athar Nakisa Kobra Azizi Iman Radfar Akbar Heydari 《应用有机金属化学》2020,34(8):e5725
A highly efficient Fe3O4@VitB1–Ag(I) magnetic catalyst has been obtained using surface modification of Fe3O4. To this end, silver chloride was immobilized on Fe3O4 nanoparticles via vitamin B1 biomolecules. The synthesized biocompatible magnetic catalyst was applied in an A3-coupling reaction in the presence of aldehyde, amine and phenyl acetylene under solvent-free conditions and afforded the desired products in excellent yields. Also, interactions between metal and ligand in the Fe3O4@VitB1–Ag(I) were studied using theoretical calculations. 相似文献
992.
《Journal of Physics and Chemistry of Solids》2014,75(8):984-991
In this work, Bi-doped magnesium silicide compounds were prepared by applying a combination of both, short-time ball milling and heating treatment. The effect of Mg excess was also studied, aiming towards further improvement in thermoelectric properties. The structural modifications of all materials were followed by Powder X-ray diffraction and Scanning Electron Microscopy. Highly dense pellets of Mg2Si1−xBix (0≤x≤0.035) and Mg2+δSi0.975Bi0.025 (δ=0.04, 0.06 and 0.12) were fabricated via hot pressing and studied in terms of Seebeck coefficient, electrical and thermal conductivities and free carrier concentration. Their thermoelectric performance, at high temperature range, is presented and the maximum value of the dimensionless-figure-of-merit (ZT) is found to be 0.68 at 810 K, for Mg2Si0.97Bi0.03. 相似文献
993.
994.
Lingjie Meng Qinglan Guo Minghua Chen Jiandong Jiang Yuhuan Li Jiangong Shi 《中国化学快报》2018,29(8):1257-1260
A glucosidic indole-lignan conjugate with a novel carbon skeleton, named isatindolignanoside A (1), was isolated from an aqueous extract of the Isatis indigotica roots “ban lan gen”. Its structure was determined by comprehensive analysis of spectroscopic data, enzyme hydrolysis, and electronic CD calculations. Compound 1 is active against Coxsackie virus B3 and represents the first example of natural product having a structural feature of conjugation between indole and lignan, and its plausible biosynthetic pathway is postulated. 相似文献
995.
Yoshihiro Hamaya 《Journal of Difference Equations and Applications》2013,19(9):805-817
We introduce the concept of the second Liapunov differences in difference equations and show that, in the autonomous case, the second variations can guarantee the existence of solutions tending to zero while others starting arbitrarily near 0 go to ∞. These are based on Yorke's results for ordinary differential equations. 相似文献
996.
We investigate the existence of unbounded solutions and the period-two convergence of solutions of the equation in the title with the parameter γ positive, the remaining parameters nonnegative, and with nonnegative initial conditions. 相似文献
997.
Md. Abdur Razzaque Sarker Satoshi WatauchiMasanori Nagao Takashi WatanabeIsamu Shindo Isao Tanaka 《Physica C: Superconductivity and its Applications》2012,472(1):87-91
Large single crystals of La2−xSrxCuO4 (LSCO) high-Tc superconductors were grown by the infrared heating floating zone (IR-FZ) method using a tilting-mirror-type image furnace. The maximum diameter of the LSCO crystals increased to 10 mm in the tilting-mirror-type image furnace from 6 mm in the conventional image furnace. CuO rich feeds were required for the crystal growth using the tilting-mirror-type image furnace to compensate for the lack of CuO caused by the significant evaporation of CuO during the growth. The evaporation of CuO was affected by the tilting angle of the mirrors of the image furnace and by feed diameter. The optimized growth conditions were as follows: mirror tilting angle, 20°; feed diameter, 10 mm∅; and feed composition 50.7 mol% CuO. 相似文献
998.
Yixuan Xie Chao Peng Yunyi Gao Xiaohong Liu Tianbo Liu Abraham Joy 《Journal of polymer science. Part A, Polymer chemistry》2017,55(23):3908-3917
Glycopolymers have been widely used to understand the interactions between carbohydrates and lectins, which facilitate the diagnosis and detection of disease and pathogens as well as the development of vaccines. While studies have been focused on the correlation of glycopolymer structure and their binding to lectins, graft‐type glycopolyesters are uncommon. Herein, we report the design and synthesis of mannose‐based graft polyesters by “grafting‐from” method and investigate their interactions with Concanavalin A (Con A). As confirmed by 1H NMR spectroscopy and sulfuric acid‐UV method, graft polyesters with different lengths of mannose graft were successfully synthesized. Our results from turbidimetry binding assay showed that graft polyesters with longer mannose graft exhibit higher initial binding rate (ki). Isothermal titration calorimetry measurements of these graft polyesters with Con A showed that polymers exhibit higher binding affinity (ka) with the number of side chain mannose. This study provides understanding of the interaction between Con A and mannose‐based graft polyesters, which can be employed for the development of glycopolymeric therapeutics. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3908–3917 相似文献
999.
《Quaestiones Mathematicae》2013,36(3):317-329
Abstract We show that every θ-proximity as defined by V.V. Fedor?uk is an f-proximity which we call a k-proximity. Two related f-proximities are introduced, viz. t- and d-proximities. The smallest and largest members of Mf(X, c) for f=k, d and t are characterised where Mf(X, c) is the family of f-proximities compatible with a given closure space (X, c). 相似文献
1000.
《Quaestiones Mathematicae》2013,36(1-4):245-262
Abstract Various familiar concepts of algebraic categories (such as primitive and quasiprimitive categories of algebras as well as varietal, monadic, regular monadic, and regular categories) are contrasted with each other and with the new notion of essentially algebraic categories. The new notion has pleasant features and covers several cases of an apparently algebraic nature, which are not covered by any of the older concepts. 相似文献