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Pt电极上吸附原子对仲丁醇电催化氧化性能的影响 总被引:1,自引:0,他引:1
运用电化学循环伏安和石英晶体微天平研究了HClO4溶液中仲丁醇在Pt电极及以Sb和S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的电催化氧化过程 .从电极表面质量变化可以看出 ,仲丁醇的氧化与电极表面的氧物种有着极其密切的关系 .Pt电极表面Sb吸附原子可在较低的电位下吸附氧 ,明显提高仲丁醇的氧化活性 .与Pt电极相比 ,Sb吸附原子修饰的Pt电极使仲丁醇氧化的峰电位负移约 10 0mV .相反 ,Pt电极表面S吸附原子的氧化会消耗表面氧物种 ,抑制仲丁醇的氧化 .从电极表面质量变化提供了吸附原子电催化作用的数据 相似文献
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本文合成了配合物[Cu(pcba)2·(phen)(H2O)] (pcba =对氯苯甲酸,phen = 1,10-邻菲罗啉),该配合物属于三斜晶系,P1空间群,晶胞参数为a=0.790 98(2) nm,b=1.072 40(4) nm,c=1.487 19(6) nm,α=100.613(3)°,β=95.239(3)°,γ=108.334(3)°,Z=2,Dc=1.638 g·cm-3,F(000)=582,最终结构残差因子R1=0.035 9,wR2=0.089 1。采用紫外及荧光研究了配合物和人血清蛋白(HSA)的相互作用方式。结果表明,配合物静态猝灭HSA荧光,可求得配合物与HSA的猝灭常数Ksv=2.35×105 L·mol-1,猝灭速率常数Kq=2.35×1013 L·mol-1·s-1,结合常数为Ka=2.14×1013 L·mol-1,结合位点n=2.37。同时,研究了配合物对胃癌细胞A549、宫颈癌细胞Hela和肝癌细胞HepG2的抗增殖能力。 相似文献
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Jin Mu Zhenfang Gu Lei Wang Zhiqing Zhang Hua Sun Shi-Zhao Kang 《Journal of nanoparticle research》2008,10(1):197-201
MnS nanocrystals with different phases and shapes were prepared through solvothermal synthesis. The products were characterized
by X-ray diffraction (XRD), transmission electron microscope (TEM), UV–vis absorption and photoluminescence (PL) spectra.
The solvent and reaction time played an important role in controlling the phase and shape of MnS nanocrystals. The possible
mechanism of the shape evolution was investigated, which revealed that the crystal growth along the unique c axis of γ-MnS resulted in the rod-like MnS at the primary period, and the tetrahedral crystal seed of β-MnS with zincblende structure resulted in the interlinking of MnS rods, so the zigzag and three-branched and palm-like MnS
appeared; with increasing reactive time the thermodynamically stable spherical α-MnS was favored through the Ostwald ripening process. The PL results showed that the intensity of γ-MnS was much weaker than that of α-MnS, and the trap state emissions of γ-MnS at 470 and 482 nm, respectively, disappeared, which might be ascribed to the difference of the shapes between the sphere
and the rod or branch. 相似文献
4.
Synthesis, Crystal Structure, and Herbicidal Activities of 2-Cyanoacrylates Containing 1,3,4-Thiadiazole Moieties 总被引:1,自引:0,他引:1
Tingting Wang Wenke Miao Shanshan Wu Guifang Bing Xin Zhang Zhenfang Qin Haibo Yu Xue Qin Jianxin Fang 《中国化学》2011,29(5):959-967
Three series of novel 2‐cyanoacrylates 7a – 7f , 9a – 9f , 10a – 10f containing 1,3,4‐thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II (PS II) electron transportation. Their structures were clearly verified by 1H NMR, 13C NMR, elemental analysis (or HRMS analysis) and single‐crystal X‐ray diffraction analysis. Bioassay showed that a suitable group at the 3‐position of acrylates was essential for high herbicidal activity. In particular, compound 7e showed the best herbicidal activities and gave 100% inhibitory activity against rape and amaranth pigweed at a dose of 1.5 kg/ha. Introduction of substituent with higher polarity such as sulfinyl or sulfonyl to the 5‐position of 1,3,4‐thiadiazole decreased herbicidal activities. 相似文献
5.
Songwei Li Guoqiang Zheng Zhenhua Jia Zhenfang Zhang Chuntai Liu Jingbo Chen 《Journal of Macromolecular Science: Physics》2013,52(5):828-838
Pure isotactic polypropylene (iPP) and that containing 0.2 wt% of a β-nucleating agent (β-NA) were extruded through a slit die. Simultaneously, the extruded melt was stretched at the die exit with different stretching rates (SR). The change of β-phase content with different SR was investigated by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The results indicate that, for pure iPP, the content of β-phase first increases with increasing SR till it reaches a maximum and then it gradually decreases. However, for the case of β-nucleated iPP, it decreases monotonously with increasing SR. The spatial confinement is considered as the best explanation for the suppression of β-phase in the nucleated iPP melt upon stretching. 相似文献
6.
Wei Zong Haiqi Gao Yue Ouyang Kaibin Chu Hele Guo Leiqian Zhang Wei Zhang Ruwei Chen Yuhang Dai Fei Guo Jiexin Zhu Zhenfang Zhang Chumei Ye Dr. Yue-E. Miao Prof. Johan Hofkens Dr. Feili Lai Prof. Tianxi Liu 《Angewandte Chemie (International ed. in English)》2023,62(27):e202218122
Competition from hydrogen/oxygen evolution reactions and low solubility of N2 in aqueous systems limited the selectivity and activity on nitrogen fixation reaction. Herein, we design an aerobic-hydrophobic Janus structure by introducing fluorinated modification on porous carbon nanofibers embedded with partially carbonized iron heterojunctions (Fe3C/Fe@PCNF-F). The simulations prove that the Janus structure can keep the internal Fe3C/Fe@PCNF-F away from water infiltration and endow a N2 molecular-concentrating effect, suppressing the competing reactions and overcoming the mass-transfer limitations to build a robust “quasi-solid–gas” state micro-domain around the catalyst surface. In this proof-of-concept system, the Fe3C/Fe@PCNF-F exhibits excellent electrocatalytic performance for nitrogen fixation (NH3 yield rate up to 29.2 μg h−1 mg−1cat. and Faraday efficiency (FE) up to 27.8 % in nitrogen reduction reaction; NO3− yield rate up to 15.7 μg h−1 mg−1cat. and FE up to 3.4 % in nitrogen oxidation reaction). 相似文献
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Lock-in phenomenon in ring laser gyroscopes is directly related to effective backscattering,which includes both backscattering and nonuniform loss.Effective backscattering often differs in different states and can only be reflected in a working state via online estimation in the working state.Moreover,effective backscattering can result in the intensity modulation of beams in the opposite directions.The effective backscattering parameters can be obtained by measuring the weak modulations in the intensity signals under different rotation rates and by using the curve-fitting method.This letter demonstrates the online estimation of backscattering. 相似文献
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聚合物中多重光散射传导的Monte Carlo数值模拟 总被引:1,自引:0,他引:1
基于米氏散射(Mie scattering)理论,建立填充分散粒子群的聚合物对光散射传导的Monte Carlo数学模型.在此基础上,编写了一套仿真模拟程序.通过模拟单个光子在聚合物中的多重散射运动过程,把问题扩展到以激光束或线状光为入射源,得到在聚合物板块内的光传导情况,并且在计算机上图像化地重现整个物理过程,对输出光强的分布情况进行模拟统计分析.模拟结果表明,利用体散射机制,可以将点光源和线光源转换为平面光输出,输出光的状态可以通过对比计算结果实施有效控制. 相似文献