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971.
This study reports the synthesis of nickel titanate (NiTiO3) powders by using the modified sol‐gel method, with nickel acetate tetrahydrate as the nickel source, titanium isopropoxide as the titanium source, and 2‐methoxyethanol as the solvent, followed by post‐heat treatment in air at temperatures ranging from 500 °C to 900 °C. The characteristics of powders were determined by X‐ray diffraction (XRD), FT‐infrared spectroscopy (FT‐IR), ultraviolet/visible spectroscopy (UV/Vis), and Raman spectroscopy. The particle size and surface area of the powders were also measured. The results indicated that single‐phase NiTiO3 can be prepared using the modified sol‐gel method, followed by post‐heat treatment at the relatively low temperature of 550 °C. The crystallite sizes and particle sizes of NiTiO3 powders increase in conjunction with the post‐heat treatment temperatures. However, the surface area of the powders shrinks as the post‐heat treatment temperatures increase. The dielectric constants of NiTiO3 powders, based on the capacitance‐voltage analysis, are within a range of 13.2 to 17.8. 相似文献
972.
Meng Liao Jiawei Wang Lei Ye Dr. Hao Sun Yunzhou Wen Chuang Wang Dr. Xuemei Sun Dr. Bingjie Wang Prof. Huisheng Peng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(6):2293-2298
Rechargeable aqueous zinc-ion batteries are attractive because of their inherent safety, low cost, and high energy density. However, viable cathode materials (such as vanadium oxides) suffer from strong Coulombic ion–lattice interactions with divalent Zn2+, thereby limiting stability when cycled at a high charge/discharge depth with high capacity. A synthetic strategy is reported for an oxygen-deficient vanadium oxide cathode in which facilitated Zn2+ reaction kinetic enhance capacity and Zn2+ pathways for high reversibility. The benefits for the robust cathode are evident in its performance metrics; the aqueous Zn battery shows an unprecedented stability over 200 cycles with a high specific capacity of approximately 400 mAh g−1, achieving 95 % utilization of its theoretical capacity, and a long cycle life up to 2 000 cycles at a high cathode utilization efficiency of 67 %. This work opens up a new avenue for synthesis of novel cathode materials with an oxygen-deficient structure for use in advanced batteries. 相似文献
973.
974.
975.
The direct C-3 alkynylation of indolizines with (2,2-dibromovinyl)arenes in the presence of palladium catalyst has been developed. This novel protocol showed wide substrate scope with respect to both indolizines and dibromoalkenes. Also this method was characterized with high efficiency and good functional group tolerance. 相似文献
976.
977.
Yin Zhao Yan-Hong Sun Zhi-Yong Li Chuang Xie Ying Bao Zhi-Jian Chen Jun-Bo Gong Qiu-Xiang Yin Wei Chen Cui Zhang 《Journal of solution chemistry》2013,42(4):764-771
The solubility of coenzyme Q10 in ethyl acetate, n-hexane, 1-butanol, 1-propanol, 2-propanol and ethanol in the temperature range 270.15–320.15 K, under atmospheric pressure, was measured by a gravimetric method and compared with the data predicted using the conductor like screening model for realistic solvation (COSMO-RS) method. The results show that the solubilities of coenzyme Q10 in the above solvents increase with temperature. The temperature dependences of predicted solubilities were consistent with the experimental data. The experimental data were correlated with the Apelblat equation. At the same temperature, the order of increasing solubility is ethyl acetate > n-hexane > 1-butanol > 1-propanol > 2-propanol > ethanol. 相似文献
978.
Shih-Chun Yang Ching-Yun Hsu Wei-Ling Chou Jia-You Fang Shih-Yi Chuang 《Molecules (Basel, Switzerland)》2020,25(23)
Diabetes mellitus is a well-known chronic metabolic disease that poses a long-term threat to human health and is characterized by a relative or absolute lack of insulin, resulting in hyperglycemia. Type 2 diabetes mellitus (T2DM) typically affects many metabolic pathways, resulting in β-cell dysfunction, insulin resistance, abnormal blood glucose levels, inflammatory processes, excessive oxidative reactions, and impaired lipid metabolism. It also leads to diabetes-related complications in many organ systems. Antidiabetic drugs have been approved for the treatment of hyperglycemia in T2DM; these are beneficial for glucose metabolism and promote weight loss, but have the risk of side effects, such as nausea or an upset stomach. A wide range of active components, derived from medicinal plants, such as alkaloids, flavonoids, polyphenol, quinones, and terpenoids may act as alternative sources of antidiabetic agents. They are usually attributed to improvements in pancreatic function by increasing insulin secretions or by reducing the intestinal absorption of glucose. Ease of availability, low cost, least undesirable side effects, and powerful pharmacological actions make plant-based preparations the key player of all available treatments. Based on the study of therapeutic reagents in the pathogenesis of humans, we use the appropriate animal models of T2DM to evaluate medicinal plant treatments. Many of the rat models have characteristics similar to those in humans and have the advantages of ease of genetic manipulation, a short breeding span, and access to physiological and invasive testing. In this review, we summarize the pathophysiological status of T2DM rat models and focus on several bioactive compounds from herbal medicine with different functional groups that exhibit therapeutic potential in the T2DM rat models, in turn, may guide future approach in treating diabetes with natural drugs. 相似文献
979.
Dr. Hongchang Jin Haiyun Wang Dr. Zhikai Qi Dr. De-Shan Bin Dr. Taiming Zhang Dr. Yangyang Wan Jiaye Chen Prof. Chenghao Chuang Dr. Ying-Rui Lu Dr. Ting-Shan Chan Dr. Huanxin Ju Prof. An-Min Cao Prof. Wensheng Yan Prof. Xiaojun Wu Prof. Hengxing Ji Prof. Li-Jun Wan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(6):2338-2342
Black phosphorus (BP) is a desirable anode material for alkali metal ion storage owing to its high electronic/ionic conductivity and theoretical capacity. In-depth understanding of the redox reactions between BP and the alkali metal ions is key to reveal the potential and limitations of BP, and thus to guide the design of BP-based composites for high-performance alkali metal ion batteries. Comparative studies of the electrochemical reactions of Li+, Na+, and K+ with BP were performed. Ex situ X-ray absorption near-edge spectroscopy combined with theoretical calculation reveal the lowest utilization of BP for K+ storage than for Na+ and Li+, which is ascribed to the highest formation energy and the lowest ion diffusion coefficient of the final potassiation product K3P, compared with Li3P and Na3P. As a result, restricting the formation of K3P by limiting the discharge voltage achieves a gravimetric capacity of 1300 mAh g−1 which retains at 600 mAh g−1 after 50 cycles at 0.25 A g−1. 相似文献
980.
Dongxin Zhang Po-Shun Chuang Dong Cao Yarkali Krishna Kola Shilpa Fujie Tanaka 《Tetrahedron letters》2018,59(23):2248-2250
A 1H NMR analysis method that detects enantiomers of molecules bearing a primary amino group has been developed. The method uses a β-keto ester-derived probe that forms enamines with the amines and is able to discriminate enantiomers of functionalized amines and amines that have chiral centers at positions remote from the amine group. 相似文献