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Pd/C气体扩散电极用于电生成H2O2降解苯酚的研究
王辉,
环境科学 , 2010,
Abstract: 采用自制的Pd/C气体扩散阴极和Ti/IrO2/RuO2阳极,在无隔膜电解槽中对苯酚模拟废水降解效果及机制进行了研究,采用电子自旋共振法(ESR)对电解体系中产生的羟自由基(·OH)进行了检测.结果表明,在Pd/C气体扩散体系中掺杂Pd催化剂可以促进H2O2的生成(H2O2的稳定浓度是7.5mg/L),有利于·OH的产生.经电化学氧化处理120min后,苯酚和COD的去除率分别达到97.2%和50%,表明在电催化氧化过程中苯酚被氧化生成了大量低分子量中间产物.废水的BOD5/COD值达到0.73是处理前的9.1倍,苯酚废水的可生化降解性通过电化学氧化处理后显著提高.在该电化学体系中苯酚的降解是在阳极直接、间接氧化及阴极产生的H2O2、·OH的氧化共同作用下完成的.通过对紫外扫描光谱图的分析推断出苯酚在电解过程中有醌类物质生成;由GC-MS检测到了邻苯二酚、对苯二酚、苯醌等芳香族化合物和己二酸、顺丁烯二酸、反丁烯二酸、丁二酸、丙二酸、乙二酸等短链羧酸,据此提出了苯酚降解的可能历程.
响应面法优化cu2bivo4可见光催化降解扑热息痛污染物工艺研究
边宇,朱亚琪,王辉,
南水北调与水利科技 , 2014,
Abstract: cu2bivo4可见光催化方法是一种去除环境中扑热息痛污染物的有效绿色方法。采用研制出的cu2bivo4催化剂在可见光条件下降解扑热息痛,运用响应变量控制法,研究了催化剂负载量、催化剂投加量、初始溶液ph值等工艺条件对降解效果的影响。在可见光照射下5h降解扑热息痛的最佳工艺条件为:催化剂投加量为80mg、催化剂负载量为5%、溶液初始ph值为6,在此工艺条件下降解扑热息痛的效率为72.6%。
Degradation Mechanism of Phenol with Electrogenerated Hydrogen Peroxide on a Pd/C Gas-diffusion Electrode
Pd/C气体扩散电极用于电生成H2O2降解苯酚的研究

WANG Hui,BIAN Zhao-yong,
王辉
,

环境科学 , 2010,
Abstract: Using a self-made Pd/C gas-diffusion electrode as the cathode and Ti/IrO2/RuO2 as the anode, the degradation of phenol was investigated in an undivided electrolysis device by the electrochemical oxidation process. Hydroxyl radical (·OH) was determined in the reaction mixture by the electron spin resonance spectrum (ESR). The result indicated that the Pd/C catalyst in Pd/C gas-diffusion electrode system accelerated the two-electron reduction of O2 to H2O2 when feeding air, which is in favor of producing ·OH. After 120 min electrolysis in Pd/C gas-diffusion electrode system, the steady concentration of H2O2 was 7.5 mg/L. The removal efficiency of phenol and COD reached about 97.2% and 50% after 120 min electrolysis, respectively, which suggested that most of phenol were oxidized to intermediates using the Pd/C gas-diffusion electrode. Furthermore, the ratio of BOD5/COD of the solutions was 9.1 times larger than the initial ones. Hence the electrochemical oxidation can enhance the biodegradation character of the phenol solution. The degradation of phenol was supposed to be cooperative oxidation by direct and/or indirect electrochemical oxidation at the anode and H2O2, ·OH produced by oxygen reduction at the cathode. UV-Vis and GC-MS identified catechol, hydroquinone, and benzoquinone as the main aromatic intermediates, and adipic, maleic, fumaric, succinic, malonic, and oxalic acids as the main aliphatic carboxylic intermediates. A reaction scheme involving all these intermediates was proposed.
Pd/石墨烯/玻碳电极检测4-氯酚污染物的研究
石 鹏,王伯轩,宋泉霖,王 辉,刘 新,
电化学 , 2015, DOI: 10.13208/j.electrochem.150603
Abstract: 采用改进的Hummers法和硼氢化钠还原法制备Pd/石墨烯催化剂,并采用XRD、SEM、XPS、TEM等技术对其进行表征.将该催化剂修饰于玻碳电极表面,制备出Pd/石墨烯/玻碳电极,使用循环伏安法研究了检测4-氯酚的最佳工作条件.研究结果表明,所得石墨烯表面平整光滑,以零价态存在的Pd纳米颗粒均匀分散到石墨烯上,平均粒径为(6.5±0.05)nm.检测4-氯酚的最佳支持电解质为0.1mol?L-1、pH=6.8的磷酸-磷酸钠缓冲溶液(PBS),峰电流与扫描速率的平方根呈良好的线性关系(R2=0.992),该电极的线性范围为1~100μmol?L-1(R2=0.967),检测限为0.57μmol?L-1(S/N=3),且具有良好的重现性和稳定性.本文所研制的Pd/石墨烯/玻碳电极具有较高的催化活性,提供了一种简便快捷、重现性好的检测4-氯酚的方法.
用于降解4-氯酚的载钯碳纳米管催化电极研究
魏祥甲,王辉,,李敏,孙德智
环境科学 , 2011,
Abstract: 采用不同体积分数的硝酸溶液(8%、15%、20%、68%)对多壁碳纳米管(MWNTs)进行预处理,使用甲醛还原方法制备出Pd/MWNTs催化剂,利用Boehm滴定法、红外光谱分析、X射线衍射(XRD)、扫描电子显微镜(SEM)及循环伏安曲线(CV)对催化剂进行表征分析,并制备成Pd/MWNTs催化阴极,在隔膜电解体系中对4-氯酚进行降解研究.结果表明,随着硝酸体积分数的增加,预处理后碳纳米管表面酸性基团的数量呈上升趋势,经过68%硝酸预处理2h后,酸性基团的量达到2.3mmol/g,羧基数量达到0.38mmol/g.制得的Pd/MWNTs催化剂上金属Pd粒径大小为9.2nm,高度分散在碳纳米管表面;在碳纳米管上负载金属Pd可以促进H2O2的生成,同时做为电极使用时可以减小外加电压,降低能耗.Pd/MWNTs催化电极对4-氯酚有较好的降解效果,在前80min通氢气条件下,阴极室发生还原性脱氯反应,后60min通入空气,阴阳极室发生了氧化反应,4-氯酚转化率和TOC去除率分别达到86.9%和71.6%。
Pd-Fe/石墨烯多功能催化阴极降解4-氯酚机制研究
祁文智,王凡,王辉,施钦,逄磊,
环境科学 , 2015,
Abstract: 制备出Pd-Fe/石墨烯多功能催化阴极,与Ti/IrO2/RuO2阳极、有机涤纶滤布构成隔膜电解体系,将阴极催化加氢脱氯作用和阴阳极氧化作用耦合起来对含4-氯酚的有机废水进行降解,采用TOC仪、紫外扫描、高效液相色谱、离子色谱分析方法研究其降解效果及反应历程.结果表明,在最佳反应条件下,Pd-Fe/石墨烯催化体系阴阳极室中4-氯酚转化率分别为98.1%和95.1%,优于Pd/石墨烯催化体系阴阳极室的93.3%和91.4%.Pd-Fe/石墨烯催化体系脱氯效果高于95%,表明双金属催化剂具有更强的析氢能力.在阴阳极的协同作用下,反应120min时4-氯酚被完全转化.通过阴极加氢脱氯作用,4-氯酚被还原成苯酚.随后苯酚在阴阳极的共同氧化作用下,被氧化生成对二苯酚、苯醌等中间产物,继而被氧化为小分子有机酸,最后被矿化为CO2和H2O,据此提出了4-氯酚降解的可能历程.
基于响应面分析法的可食性小麦蛋白膜的研究
梁桂,
食品科学 , 2004,
Abstract: ?应用响应面分析法研究了谷朊粉浓度、甘油浓度、ph值、成膜温度对成膜特性的影响。实验结果表明,甘油浓度与ph值及其交互作用对蛋白膜抗拉强度和延伸率影响比较显著;对膜的透水性影响比较大的因素是甘油浓度、温度、谷朊粉浓度及甘油浓度与温度的交互作用;谷朊粉浓度、甘油浓度、ph值、温度以及它们的交互作用对蛋白膜的透氧性的影响都是比较显著的。
脾气虚证本质研究的途径与方向
王建华,
中国中医药信息杂志 , 2000,
Abstract: <正>脾气虚证本质研究是中西医结合证本质研究的重要内容。近二十多年来有关脾气虚证本质研究主要围绕脾主运化开展,研究认为:脾气虚证主要表现为唾液淀粉酶活性比值降低,尿d-木糖排泄率下降,胃肠运动功能紊乱,胃肠粘膜有关细胞线粒体数量减少及其结构异常,胃肠道激素异常等。
Electrochemical Degradation of 4-Chlorophenol Using a Pd/MWNTs Catalytic Electrode
用于降解4-氯酚的载钯碳纳米管催化电极研究

WEI Xiang-ji,WANG Hui,BIAN Zhao-yong,LI Min,SUN De-zhi,
魏祥甲
,王辉,,李敏,孙德智

环境科学 , 2011,
Abstract: Nitric acid in various volume fraction(8%, 15%, 20%, and 68%) was used on the multi-wall carbon nanotubes(MWNTs) pre-treatment and then the formaldehyde reduction method was utilized for the preparation the Pd/MWNTs catalysts which were fully characterized by Boehm titration method, X-ray diffraction(XRD), infrared spectroscopy, scanning electron microscopy(SEM), and cyclic voltammetry(CV) techniques. The electrochemical degradation of 4-chlorophenol was investigated in a diaphragm electrolysis system using the Pd/MWNTs gas-diffusion cathode. The results indicated that the active organic function groups increased on the surface of the carbon nanotube pre-treated by using 68% nitric acid. Pd particles with an average size of 9.2 nm were highly dispersed in the carbon nanotube with an amorphous structure. Additionally, the Pd/MWNTs catalyst in Pd/MWNTs gas-diffusion electrode system accelerated the two-electron reduction of O2 to hydrogen peroxide(H2O2) when feeding air. The Pd/MWNTs gas-diffusion cathode can not only reductively dechlorinate 4-chlorophenols by feeding hydrogen gas, but also accelerate the two-electron reduction of O2 to H2O2 by feeding air. Therefore, the removal efficiency and the average removal efficiency of 4-chlorophenol in terms of total organic carbon(TOC) reached about 86.9% and 71.6% after 140 min electrolysis, respectively.
Clinical TCM Evaluation:Problems and Response Strategies
中医药临床研究疗效评价中存在的问题与对策

Bian Zhaoxiang,

世界科学技术-中医药现代化 , 2007,
Abstract: Evaluation of TCM clinical therapeutic effects is to review the acceptance of the standards for such evaluation,and associated diffusions and implementation. The establishment of a well-functioned and widely recognized evaluation system, and well regulated random and control experimental requirements, can greatly raise the quality and level of evaluation of TCM clinical therapeutic effects. This paper analyzes an array of aspects of standardization, including clinical TCM nomenclatures,symptom expressions, diagnosis, and evaluation of therapeutic effects. In the meantime, author proposes to strengthen methodology training for clinical study, in an attempt to avoid possible bias, along with the strategies for systematic evaluations.
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