检索结果-南通市图书馆

Journal of Environmental Sciences 2003年第3期15卷 396-400页

作者： ZHOUDong-mei ZORNRoman CzurdaKurt LMCP lnstituteofSoilScienceChineseAcademyofSciencesNanjing210008China.E-mail.dmzhou@*** DepartmentofAppliedGeology KarlsruheUniversityKarlsruheGermany

This report examined electrochemical remediation of copper contaminated kaolinite by controlling electrolytes′ pH for both of anolyte and catholyte simultaneously. Results showed that electrokinetic process and remediation efficiency varied obviously when different buffer systems, including citric acid (test 1), nitric acid + EDTA (test 2) and nitric acid (test 3), were used to control catholyte pH and Na_2CO_3 was used at the same time to control all anolyte one. It was found that under such pH condition soil′s pH in soil column kept at 3.0—7.0 successfully, and correspondingly no copper precipitation and decrease of soil electroconductivity appeared, which are usually observed in electrokinetic process due to OH - introduction into soil column by electrochemical reaction occurred in cathode. Electroosmosis flow rates were almost equal for these three tests, indicating that these buffers did not affect Zeta-potential of kaolinite within the examined duration. More acid and basic solution was added into electrokinetic cell when nitric acid was used as buffer than when nitric acid + EDTA and then citric acid were used. Due to introduction of large amounts of ions into soil column, significant higher current was observed for test 3 than other two. Analysis of copper speciation and total quantity in kaolinite indicated that 22.5%, 23.74% and 55.65% Cu were removed from kaolinite for test 1, test 2 and test 3 respectively after only 10 days′ electrokinetic remediation.

关键词： copper kaolinite pH control electrokinetic remediation

copper-comprising nanocrystals as well-defined electrocatalysts to advance electrochemical CO_(2) reduction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第11期30卷 71-102,I0002页

作者： Jianfeng Huang Tianyi Yang Ke Zhao Shuangqun Chen Qin Huang Yu Han Multi-scale Porous Materials Center Institute of Advanced Interdisciplinary StudiesSchool of Chemistry and Chemical EngineeringChongqing UniversityChongqing 400044ChinaAdvanced Membranes and Porous Materials CenterKing Abdullah University of Science and TechnologyThuwal 23955-6900Saudi Arabia

In the continuous development of electrochemical CO_(2) reduction (ECR), Cu-based electrocatalysts have received great attention, due to their unique ability to produce high value-added multicarbon products. Of particular interest are various Cu-comprising nanocrystals, not only because they usually show better catalytic properties than bulk materials, but also because their well-defined structures and highly tunable compositions facilitate in-depth mechanistic studies. This review aims to summarize the latest developments of electrocatalysts for ECR, with a focus on systems using Cu-comprising nanocrystals. We first give a general introduction to the field of ECR, covering the significance of this process, reaction mechanisms, catalyst evaluation criteria, and electrolytic cell configurations. Next, we discuss Cu-comprising nanocrystals developed for ECR by categorizing them into four groups: monometallic copper, copper-containing bimetals/multimetals, copper compounds, and copper–metal oxide hybrids;among these groups, we choose representative examples for detailed discussion on the synthetic methods, structural and compositional reaction sensitivities, and catalyst evolution during ECR. In the last section, we outline the challenges in this field from the fundamental and applicative aspects, and give perspectives on the expansion of catalyst varieties, the identification and preservation of active sites, and the exploration of industrially relevant operations for these nanocrystals. We hope the insights provided in this review will inspire the design and development of next-generation catalysts for ECR.

关键词： copper Nanocrystals Electrocatalysts Carbon-dioxide reduction Restructuring

Extraction of copper from sewage sludge using biodegradable chelant EDDS

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2008年第8期20卷 970-974页

作者： ZHANG, Lihua ZHU, Zhiliang ZHANG, Ronghua ZHENG, Chengsong ZHANG, Hua QIU, Yanling ZHAO, Jianfu State Key Laboratory of Pollution Control and Resource Reuse Tongji University Shanghai 200092 China Department of Chemistry and Biology Engineering Sanming College Sanming Fujian 365004 China Sanming Environment Protection Bureau Sanming Fujian 365004 China

[S,S]-Ethylenediaminedisuccinic acid(EDDS),a biodegradable chelant,was used to separate the heavy metals from the sewage sludge based on chemical extraction technology.Under various conditions,the extraction experiments were carried out for the sewage sludge from Shanghai Taopu Municipal Wastewater Plant,China.The influences ofpH and the concentration of EDDS on the extraction efficiency for copper(Cu)were discussed.The results showed that EDDS had higher extraction efficiency for Cu from the sewage sludge ...

关键词： copper EDDS extraction sewage sludge biodegradable

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2007年第10期19卷 1235-1238页

作者： LIU Ting-feng SUN Cheng TA Na HONG Jun YANG Shao-gui CHEN Chuan-xiang State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanfing 210093 China School of Material Science and Engineering Jiangsu University of Scienee and Technology Zhenjiang 212003 China

The influence of coexisting copper （Cu） ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied. Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time, the analysis of the extracts from the soil was carded out using gas chromatography （GC）. The photodegradation of pyrethroids in water system was conducted under UV irradiation. The effect of Cu^2＋ on the pesticides degradation was measured with half life 00.5） of degradation. It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed. But Cu^2＋ could accelerate photodegradation of the pyrethroids in water. The t0.5 for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil. As for photodegradation, t0.5 for cyhalothrin reduced from 173.3 to 115.5 min and for cypermethrin from 115.5 to 99.0 min. The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms. However, it had catalyst tendency for photodegradation in water system. The difference for the degradation efficiency of pyrethroid isomers in soil was also observed. copper could obviously accelerate the degradation of some special isomers.

关键词： degradation photodegradation copper cypermethrin cyhalothrin

Sediment-copper distributions in hyper-concentrated turbulent solid-liquid system

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2007年第1期19卷 123-127页

作者： YANG Jun NI Jin-ren Department of Environmental Engineering Beihang University Beijing 100083 China College of Environmental Sciences Peking University Key Laboratory for Water and Sediment Sciences Ministry of Education Beijing 100871 China

This study presents a special problem on vertical distribution for sediment and copper in hyper-concentrated turbulent solid-liquid system that is essentially different from the ordinary low-concentrated turbulent system. A resonance type turbulent simulation equipment is used for the experimental study in which a vertically uniform turbulent field of the mixture of loess and water is produced in a testing cylinder with a grille stirrer that moves up and down harmoniously with varying vibration frequencies, in order to compare the variations of the vertical profiles of sediment and copper in low- and hyper-concentratod solid-liquid system, different scenarios for input sediment content ranging from 5 to 800 kg/m^3 was considered in the experimental studies. It was found that solids copper content increases with input sediment content, So, and reaches its peak as So goes to 10 kg/m^3 and then decreases rapidly with increasing input sediment content. Such a behavior is possibly resulted from the joint effect of the specific adsorption of copper on loess, precipitation of carbonate and hydroxide of copper due to high carbonate content in the loess and the so-called ＂particulate concentration effect＂ due to the present of the sediment variation in water. The vertical sediment concentration distribution resulted from the uniform turbulence is generally uniform, but slight non-uniformity does occur as sediment concentration exceeds certain value. However, the vertical concentration distributions of soluble copper seem not to be affected much by the variation of sediment concentrations.

关键词： hyper-concentrated system loess copper vertical sediment distribution

Effects of copper-aspirin complex on platelet-neutrophil interactions

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第5期25卷 34-38页

作者： Zhi-qiang SHEN2, Peng CHEN3, Ling LI, Peng CHEN, Wei-ping LIU4Yunnan Pharmacological Laboratories of Natural Products, Kunming Medical College, Kunming 650031, China 3Kunming Shenghuo Pharmaceutical Ltd Co, Kunming 650217 4Kunming Institute of Precious Metals, Kunming 650221, China. 昆明医学院云南省天然药物药理重点实验室 Kunming 650031 Kunming Shenghuo Pharmaceutical Ltd Co Kunming 650217 Kunming Institute of Precious Metals Kunming 650221

AIM: To investigate the effects of copper-aspirin complex on rat thrombosis and the interaction between plateletsand neutrophils. METHODS: The model of electrically stimulated carotid artery thrombosis in Sprague Dawleyrats was used; the effects of copper-aspirin complex on rat platelet-neutrophil adhesion and platelet aggregationstimulated by activated neutrophils were observed by rosette assay and Borns method, respectively. RESULTS:Intragastric copper-aspirin complex (5, 7, and 10 mg/kg) dose-dependently prolonged the occlusion time; it signifi-cantly decreased the rosette number formed between thrombin-activated platelets and neutrophils; the 50 % ofinhibitory concentration (IC50) was (54.64.3) mol/L. copper-aspirin complex markedly inhibited rat plateletaggregation induced by either cell free supernatant of activated neutrophils or by activated neutrophil suspension.The values of IC50 were (224.516.2) mol/L and (820.521.4) mol/L, whereas aspirin had no influence.CONCLUSION: copper-aspirin complex inhibited platelet-neutrophil interactions through a different property fromaspirin and resulted in a more potent antithrombotic activity.

关键词： copper aspirin thrombosis platelets neutrophils adhesion platelet aggregation

copper Adsorption on Olivine

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 237-241页

作者： Lei Shao, Rolf A. Kleiv, Kunt L. Sandvik, Cunyi Song, Shouci Lu ( Resources Engineering School, University of Science and Technology Beijing, Beijing 100083, China Department of Geology and Mineral Resources Engineering, Norwegian University of Science a Resources Engineering School University of Science and Technology Beijing Beijing 100083 China Department of Geology and Mineral Resources Engineering Norwegian University of Science and Technology 7034 Trondheim Norway

copper adsorption on olivine supplied by the A/S Olivine Production Plant at Aheim in western Norway was studied. The factors were evaluated which affect the uptake of copper. It is shown that the equilibrium pH of aqueous solution has the greatest influence on copper adsorption thanks to the competitive adsorption between proton and copper ions, and the adsorption of copper to olivine increases rapidly with pH increasing from 4 to 6. Moreover, initial copper concentration and olivine dose possess significant effect on copper adsorption, for the adsorption rate of copper increases with olivine dose increasing or initial copper concentration decreasing at the same pH. In addition, the ionic strength effect on the adsorption was also investigated, but it owns little effect on the adsorption process of copper due to the formation of inner sphere adsorption of copper on olivine. The experimental data show that olivine has a high acid buffer capacity and is an effective adsorbent for copper.

关键词： copper adsorption olivine, ionic strength acid mine drainage

copper-catalyzed amide bond formation from formamides and carboxylic acids

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2015年第1期26卷 11-14页

作者： Hong-Qiang Liu Jun Liu Yang-Hui Zhang Chang-Dong Shao Jing-Xun Yu Department of Chemistry Tongji University Key Laboratory of Yangtze River Water Environment Ministry of EducationTongji University

A highly efficient copper-catalyzed approach to form amide bonds from formamides and carboxylic acids was developed. This protocol shows broad substrate scopes and high yields in the presence of 1 mol% catalyst and 4.... 详细信息

关键词： Amides Formamides Carboxylic acids copper Catalysis

copper-catalyzed N-arylation of 2-arylindoles with aryl halides

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2014年第9期25卷 1240-1243页

作者： Wei Liu Li-Ya Han Rui-Li Liu Li-Ge Xu Yan-Lan Bi College of Food Science and Technology Henan University of Technology

10 mol% Cul combined with the DMEDA ligand can efficiently catalyze the N-arylation of 2-arylindoles with aryl iodides and aryl bromides in good to excellent yields. The aryl halides bearing electron-rich or electron-... 详细信息

关键词： 2-Arylindoles Aryl halides N-Arylation copper

copper(Ⅱ)-catalyzed enantioselective conjugate addition of nitro esters to 2-enoyl-pyridine N-oxides

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2019年第3期30卷 569-572页

作者： Jianan Sun Yanan Li Yang Gui Youguo Xu Zhenggen Zha Zhiyong Wang Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Soft Matter Chemistry & Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences Collaborative Innovation Center of Suzhou Nano Science and Technology & School of Chemistry and Materials ScienceUniversity of Science and Technology of China

A highly enantioselective Michael addition of nitro esters to 2-enoyl-pyridine N-oxides was developed by using chiral copper catalysts. The Michael addition products can be obtained in high yields and with up to 96% ee. Moreover, asymmetric Michael addition product of nitromethane to 2-enoyl-pyridine N-oxides can be obtained in one step. An analogue of nicotine, dihydro-2H-pyrrol 4b was synthesized with this developed method.

关键词： Michael reaction Asymmetric catalysis copper catalysis Nitro esters 2-Enoyl-pyridine N-oxides