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排序方式: 共有1710条查询结果,搜索用时 31 毫秒
61.
Nonlinear Dynamics - In this paper, the Riemann–Hilbert approach is systematically established for the Newell-type long-wave–short-wave equation. Firstly, we start spectral analysis... 相似文献
62.
<正>Topochemically-controlled stereoselective [2+2] photocycloadditions are now well-established in the literatures.The construction of cyclobutane rings has attracted considerable attention due to the existence of this structural motif in natural products and synthetic medicines. Furthermore, cyclobutane derivatives appended with pyridyl or carboxylic groups exhibit intriguing properties in some ad- 相似文献
63.
Zhongchao Jin Dr. Xiaorong Zhu Dr. Ningning Wang Prof. Dr. Yafei Li Prof. Dr. Huangxian Ju Prof. Dr. Jianping Lei 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10532-10536
Metal–organic frameworks (MOFs) have limited applications in electrochemistry owing to their poor conductivity. Now, an electroactive MOF (E-MOF) is designed as a highly crystallized electrochemiluminescence (ECL) emitter in aqueous medium. The E-MOF contains mixed ligands of hydroquinone and phenanthroline as oxidative and reductive couples, respectively. E-MOFs demonstrate excellent performance with surface state model in both co-reactant and annihilation ECL in aqueous medium. Compared with the individual components, E-MOFs significantly improve the ECL emission due to the framework structure. The self-enhanced ECL emission with high stability is realized by the accumulation of MOF cation radicals via pre-reduction electrolysis. The self-enhanced mechanism is theoretically identified by DFT. The mixed-ligand E-MOFs provide a proof of concept using molecular crystalline materials as new ECL emitters for fundamental mechanism studies. 相似文献
64.
Guanjia Zhu Prof. Wan Jiang Prof. Jianping Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(7):1488-1496
The successful commercialization of promising silicon-based anode materials has been hampered by their poor cycling stability caused by the huge volume change. Integration of the carbon matrix with silicon-based (C/Si-based) anode materials has been demonstrated to be a powerful solution to achieve satisfactory electrochemical performance. This minireview aims to outline recent developments on C/Si-based composites, with the emphasis on the importance of carbon distribution at multiple scales. In addition, the forms of the carbon framework (carbon sources and doping of heteroatoms) have been summarized. Particularly, a novel C/Si-based hybrid with carbon distributed at the atomic scale has been highlighted. 相似文献
65.
Huang Jianping Chen Fang Wang He Yan Hongge 《Research on Chemical Intermediates》2018,44(4):2729-2738
Research on Chemical Intermediates - The combination of the unique properties of graphene with functional characteristics of metal oxides is an interesting pathway to achieve desirable properties... 相似文献
66.
A corona discharge (CD) ion mobility spectrometer combined with solid-phase microextraction was constructed. The detection limit and stability of the system for malathion detection were improved using a novel sample introduction port through which the sample desorption was performed in high-temperature drift tube and the sample was introduced directly to the ionization area. The working parameters of the distance between CD needle tip and carrier gas outlet, the drift tube and carrier gas temperature, the carrier gas flow, and the voltage on CD needle were selected. When the extraction time for standard malathion was set to 5?min, the detection limit was 0.96?µg?L?1 based on thrice the baseline noise, the linear range was 50–500?µg?L?1, the correlation coefficient was approximately 0.9941, and the relative standard deviation was below 10%. Malathion-spiked lake water samples were analyzed using the developed system and the recovery was 92–102%. This method is suitable for the rapid detection of organophosphorus pesticide residues. 相似文献
67.
68.
This paper analyzes the high bit-rate optical pulse trasmission in single mode optical fiber with chromatic dispersion, polarization mode dispersion (small random birefringence) and nonlinearity. Numerical method employed can precisely describe their interactive effect on transmission performance. Different dispersion maps and the related performance are analysed. Various simulation results and discussion are given. The results show that chromatic dispersion compensation should be carefully designed. Appropriate dispersion management can also alleviate the effect of polarization mode dispersion. 相似文献
69.
H^—5的正四面体中心和正方形中心构型能量的理论计算 总被引:1,自引:1,他引:1
文中用MACQM(modifiedarangementchannelquantummechanics)方法计算了负离子团簇H-5的正四面体中心和正方形中心构型的能量随中心原子核到顶角原子核间距离R变化的曲线。计算得知,两种构型均在R=1.55a0时有能量极小值E正四面体中心=-2.7899a.u.,E正方形中心=-2.7539a.u.。说明H-5的这两种结构都可能存在,但正四面体中心结构较为稳定。 相似文献
70.
Xie Yuanxiang Xu Shuwei Guo Yingxiang Ma Ruichang Ge Yuanxiu Li Zhankui Wang Chunfang Guo Bin Xing Jianping Zhang Tianmei Zhu Shaofei Xu Wang 《中国物理C(英文版)》1997,21(4):289-291
209Fr has been produced by irradiation of 197Au with 16O from SFC accelarator uia the fusion-evaporation 4n channel.The(EC+β+)decay of 209Fr has been studied by a He-jet tape transport system.The decay scheme is proposed for the first time based on γ-t,X-γ-t,γ-γ-t coincidece and γ-γ delay coincidence measurements,which takes account of 20 observed γ ray.Five members of low-lying states in 209Rn can be explained by the multi-plet [(210Rn2+)(νf5/2)-1].The branching ratio for(EC+β+) decay of 209Fr has been estimated experimentaly to be(3.0±1.5)%. 相似文献