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41.
主要讨论了非线性方程F(λ,u)=λu-G(u)=θ的分歧问题,其中G:X→X为非线性可微映射,X为Banach空间.在G′(θ)为紧算子,N(λ~*I-G′(θ))\R(λ~*I-G′(θ))≠{θ}的条件下,利用Lyapunov-Schmidt约化过程和隐函数定理证得了方程F(λ,u)=θ在多重特征值处的分歧定理,推广了Krasnoselski的经典分歧定理. 相似文献
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43.
Huiwen Zheng Hailin Zhang Yu Fan Ge Ju Hongbin Zhao Jianhui Fang Jiujun Zhang Jiaqiang Xu 《中国化学快报》2020,31(1):210-216
Recently,the development of new electrode materials for lithium-ion batteries(LIBs)has received intensive attention.As an important family of inorganic materials,mixed Mo-based transition metal oxides system is focused as anode materials.In the present work,a simple route has been adopted for the synthesis of layered-flake-likeβ-SnMo04 Nano-assemblies,which have been explored as potential anode materials for the first time in lithium-ion battery(LIB).Overall,the current reports on metal molybdate as anode materials are still rarely.As the anode material for LIBs,it was observed that the fabricated anode is capable of delivering a steady state capacity of almost 400 mAh/g up to 300 cycles under the influence of200 mA/g current density.Further,the anode material is suitable for use as a rated capacity anode because of its high current density tolerance.The present study can be further extended for the generation of a wide variety of other novel materials for multidisciplinary energy related applications. 相似文献
44.
Wanjun Zhang Jingyi Wang Yashu Chen Hongbin Zheng Bijun Xie 《Natural product research》2020,34(11):1621-1625
AbstractThe flavonoid compositions, extracted from leaves, peel and flesh of white guava (Psidium guajava L. cv. Pearl), were identified and quantified by UPLC-ESI-QTOF-MS, HPLC-ESI-MS/MS and HPLC. The main components of three extracts all were quercetin-glycosides, but the proportion and content of quercetin-hexoside and quercetin-pentoside in each extract were different. Based on the measurements of MIC, MBC value and time killing curve, it emerged that 3 flavonoid extracts of white guava had good antibacterial effects on four pathogenic bacteria. White guava leaves flavonoids (WGLF) concentrations of 5.00?mg/mL and 0.625?mg/mL could change the micro-morphology of Escherichia coli and Staphylococcus aureus. It suggested that the antibacterial mechanism of WGLF on gram-positive and gram-negative bacteria was to destroy the structure and function of the cell membrane. It is indicated that the flavonoid extracts from white guava is a potential natural antimicrobial agent. 相似文献
45.
Yueting Li Jie Liu Rubin Su Qian Li Yijun Chen Jiao Yang Shujun Zhao Zhixin Jia Hongbin Xiao 《Journal of separation science》2020,43(6):1032-1042
Detection and determination of many known/unknown compounds in traditional Chinese medicines have always been challenging. To comprehensively identify compounds in Qishen granule, which is a widely prescribed herbal formula for treating chronic heart failure, a pseudotargeted screening method was proposed based on compound biosynthetic correlation using ultra high‐performance liquid chromatography coupled with high‐resolution mass spectrometry. Firstly, all possible compounds of Qishen granule were classified into nine types according to their core skeletons, and potential analogue molecular formulas were predicted according to core compound‐related biosynthetic correlations, such as methylation, hydroxylation, and glucosidation. Secondly, nine pseudocompound databases consisting of core compounds, deduced biosynthetic correlations, and predicted analogue molecular formulas were established. Then, compounds of interest were directly located by pseudotargeted screening of high resolution mass spectrometry data and further verified by target tandem mass spectrometry. As a result, 213 constituents were identified and 21 of them were determined as potential new compounds. This demonstrated that pseudotargeted screening based on compound biosynthetic correlations significantly facilitated the processing of extremely large information data and improved the efficiency of compound identification. This research provided essential data for exploration of effective substances in Qishen granule and enriched the methodology for comprehensive characterization of constituents in complex traditional Chinese medicines. 相似文献
46.
采用高温固相法制备系列红色荧光粉Naz Ca1-x-2y-zBiyMoO4 ∶ Eu3+x+y (y,z=0,x=0.24,0.26,0.30,0.34,0.38; x=0.30,y=0.01,0.02,0.03,0.04,0.05,0.06,0.07,z=0; x=0.30,y=0.04,z=0.38).用X射线粉末衍射(XRD)法测试了所制样品晶相结构.采用荧光光谱仪对样品的发光性能进行了表征,结果表明:当Eu3+单掺杂量浓度x=0.30时,荧光粉(Ca0.70 MoO4∶Eu3+0.30)的发光强度最强;当Eu3+-Bi3+共掺杂量浓度y=0.03时,电荷迁移带(CTB)强度达到最强,而对于Eu3+特征发射峰,当共掺杂浓度y<0.03时,位于393 nm处的激发峰强度比464 nm强,共掺浓度y>0.03时,464 nm峰比393 nm峰强,共掺浓度为y=0.04时,393和464 nm处两峰位置强度都达到最强.作为电荷补尝剂的Na2 CO3掺入上述荧光粉中后,荧光粉激发和发射强度明显地增强.结果表明,通过调节Bi3+ /Eu3+掺杂比例可以改变位于近紫外光393 nm和蓝光区464 nm处激发光相对强度. 相似文献
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48.
β-环糊精用于毛细管电泳拆分佐匹克隆对映体的研究 总被引:1,自引:1,他引:0
以β-环糊精(β-CD)为手性添加剂,用毛细管区带电泳法对手性药物佐匹克隆进行了拆分研究.考察了β-环糊精浓度、背景电解质组成、浓度及pH值、分离电压、温度等对对映体分离的影响.结果表明,以pH 2.5的100 mmol/L三羟甲基氨基甲烷-磷酸溶液(含15 mmol/L β-环糊精)为运行缓冲液,分离电压28 kV,毛细管温度16 ℃,检测波长303 nm,佐匹克隆对映体达到最佳分离,分离度为2.7,对映体迁移时间分别为8.4、8.9 min.该方法简单、快速、经济,可适用于佐匹克隆对映体的手性分离. 相似文献
49.
采用平衡法测定了丙烯腈+水、己二腈+水、丙腈+水三个二元体系在不同温度(303.15、313.15、323.15、333.15K)下的液-液相平衡数据;并采用NRTL(α=0.2,α=0.3)模型和UNIQUAC模型对液-液平衡数据进行了关联.结果显示,NRTL和UNIQUAC模型对三个二元体系在不同温度下的互溶度关联的目标函数值均小于1×10-17,实验值与计算值吻合较好,绝对偏差小于0.009,关联精度较高.该研究结果可为丙烯腈、丙腈和水三元平衡溶解度数据的模拟和预测提供可靠的基础数据,并对电解二聚法生产己二腈中电解液的分离提纯工艺具有一定的指导意义. 相似文献
50.
Improvements for ground-based remote sensing of atmospheric aerosol properties by additional polarimetric measurements 总被引:1,自引:0,他引:1
Zhengqiang Li Philippe Goloub Oleg Dubovik Luc Blarel Wenxing Zhang Thierry Podvin Alexander Sinyuk Mikhail Sorokin Hongbin Chen Brent Holben Didier Tanr Marius Canini Jean-Pierre Buis 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(17):1954-1961
We discuss the improvements in the aerosol properties characterization resulting from the additional multi-wavelength polarization measurements measured by a new CIMEL polarized sun/sky-photometer, CE318-DP. In order to process direct-sun, sky and polarization measurements in a wide spectral range (340–1640 nm), we developed new calibration methods and strategies, e.g. using the Langley plot method to calibrate both direct-sun irradiance and sky radiance, as well as combining laboratory facilities with a vicarious method to calibrate the polarized sky measurements. For studying the impact of new polarimetric measurements on the retrievals of aerosol properties, we have processed an extensive record of field measurements using an updated Dubovik and King retrieval algorithm [Dubovik O, Sinyuk A, Lapyonok T, Holben BN, Mishchenko MI, et al. Application of spheroid models to account for aerosol particle nonsphericity in remote sensing of desert dust. J Geophys Res 2006;111:D11208.]. A preliminary analysis shows that adding polarization in the inversion can reduce possible errors (notably for about 30% of our field cases) in the fine mode size distribution, real part of refractive index and particle shape parameter retrievals, especially for small particles. 相似文献