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101.
Effects of temperature and sodium carboxylate additives on mineralization of calcium oxalate in silica gel systems 总被引:5,自引:0,他引:5
Bernd Tieke 《中国科学B辑(英文版)》2004,47(4):311-319
Urolithiasis remains a major medical problem in China, especially in Guangdong Province in the southest of China[1]. A survey in Shenzhen city, the most southern city in China, showed the incidence of renal calculus was 4.87%, being 6.12% in the males and 4.07% in the females[2]. The prevalence of renal calculus has been more as the age advances and in the male population and so was in the less-educated population. The recurrence rate is more than 80%, with a moderate improvement by conventi… 相似文献
102.
A catalytic asymmetric conjugate addition/Schmidt-type rearrangement of vinyl azides and (E)-alkenyloxindoles was realized. It afforded a variety of optically active 3,2′-pyrrolinyl spirooxindoles with high yields (up to 98%), and excellent diastereo- and enantioselectivities (up to 98% ee, >19 : 1 dr), even at the gram-scale in the presence of a chiral N,N′-dioxide–nickel(ii) complex. In addition, a possible catalytic cycle and transition state model were proposed to rationalize the stereoselectivity.Lewis acid catalyzed asymmetric synthesis of 3,2′-pyrrolinyl spirooxindole skeletons via conjugate addition/Schmidt-type rearrangement of vinyl azides and (E)-alkenyloxindoles. 相似文献
103.
Yizhao Ouyang Miao Zhan Jing Zhou Jiao Jiao Hao Hu Yoichi M. A. Yamada Pengfei Li 《中国化学》2019,37(8):807-810
A rigid C2‐symmetric chiral bipyridine ligand Z‐bpy with a triptycene‐like backbone was designed and synthesized from simple chemicals in a scalable route. Using this new ligand, copper(I) catalyzed cyclopropanation of styrenes with commercial ethyl diazoacetate produced various corresponding cyclopropanes in high yields, diastereoselectivity and enantioselectivity up to 97% ee. 相似文献
104.
Xiaoming Liu Colin A. Kilner Malcolm A. Halcrow 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(5):m290-m291
The title compound, [Fe2Cl4O(C7H12N2)4], contains vertex‐sharing distorted tetrahedral [FeOCl3]? and octahedral [FeOCl(HpztBu)4]+ moieties (HpztBu is 5‐tert‐butylpyrazole), linked by a bent oxo bridging ligand. The two FeIII centres are also bridged by intramolecular hydrogen bonds between the pyrazole N—H groups and the O2? and Cl? ligands. 相似文献
105.
Ouyang Jinbo Wang Yun Li Tianqi Zhou Limin Liu Zhirong 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(3):1419-1428
Journal of Radioanalytical and Nuclear Chemistry - The carboxyl-modified multiwalled carbon nanotubes were immobilized in chitosan-based composite membranes (CS-CNTs) which were used as efficient... 相似文献
106.
Zirui Song Kangyu Zou Xuhuan Xiao Xinglan Deng Shuo Li Prof. Dr. Hongshuai Hou Prof. Dr. Xiaoming Lou Prof. Dr. Guoqiang Zou Prof. Dr. Xiaobo Ji 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(65):16082-16092
Nowadays sodium-based energy storage systems (Na-based ESSs) have been widely researched as it possesses the possibility to replace traditional energy storage media to become next generation energy storage system. However, due to the irreversible loss of sodium ions in the first cycle, development of Na-based ESSs is limited. Presodiation, as a strategy of adding excess sodium ions to the system in advance, accomplishes the enhancement of electrochemical performance. In this minireview, different presodiation strategies applied in sodium-based energy storage systems will be summarized in detail, their functions and corresponding mechanisms will be discussed as well. Furthermore, the current novel application of presodiation method in other aspects of Na-based ESSs will be mentioned additionally. At last, in the view of present research status of presodiation, issues that can be mitigated are put forward and guidelines are given on how to deliberate in-depth presodiation technology in the future, dedicating to promote the further development of Na-based ESSs. 相似文献
107.
We consider the MAP/PH/N retrial queue with a finite number of sources operating in a finite state Markovian random environment. Two different types of multi-dimensional Markov chains are investigated describing the behavior of the system based on state space arrangements. The special features of the two formulations are discussed. The algorithms for calculating the stationary state probabilities are elaborated, based on which the main performance measures are obtained, and numerical examples are presented as well. 相似文献
108.
Ling Wang Xiao-Tong Wang Jia-Huan Zhong Dr. Kang Xiao Dr. Ting Ouyang Prof. Zhao-Qing Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(18):5796-5802
The high charge–discharge voltage gap is one of the main bottlenecks of zinc–air batteries (ZABs) because of the kinetically sluggish oxygen reduction/evolution reactions (ORR/OER) on the oxygen electrode side. Thus, an efficient bifunctional catalyst for ORR and OER is highly desired. Herein, honeycomb-like MnCo2O4.5 spheres were used as an efficient bifunctional electrocatalyst. It was demonstrated that both ORR and OER catalytic activity are promoted by MnIV-induced oxygen vacancy defects and multiple active sites. Importantly, the multivalent ions present in the material and its defect structure endow stable pseudocapacitance within the inactive region of ORR and OER; as a result, a low charge–discharge voltage gap (0.43 V at 10 mA cm−2) was achieved when it was employed in a flexible hybrid Zn-based battery. This mechanism provides unprecedented and valuable insights for the development of next-generation metal–air batteries. 相似文献
109.
110.
Hui Shi Ziheng Wang Dr. Qin Ouyang Prof. Jianwei Hao Dr. Xianbo Huang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(30):8030-8039
Retaining nitrogen for polyacrylonitrile (PAN) based carbon anode is a cost-effective way to make full use of the advantages of PAN for sodium-ion batteries (SIBs). Here, a simple strategy has been successfully adopted to retain N atoms in situ and increase production yield of a novel composite PAZ by mixing 3 wt % of zinc borate (ZB) with poly (acrylonitrile-co-itaconic acid) (PANIA). Among the prepared carbonised fibre (CF) samples, PAZ-CF-700 maintains the highest N content, retaining 90 % of the original N from PANIA. It represents the highest capacity storage contribution (80.55 %) and the lowest impedance Rct (117 Ω). Consequently, the specific capacity increases from 60 mAh g−1 of PANIA-CF-700 to 190 mAh g−1 of PAZ-CF-700 at a current density of 100 mA g−1. At the same time, PAZ-CF-700 exhibits a good rate performance and excellent long-term cycling stability with a specific capacity of 94 mAh g−1 after 4000 cycles at 1.6 A g−1. 相似文献