期刊文献+
共找到234篇文章
< 1 2 12 >
每页显示 20 50 100
乙乙乳膏对软组织损伤局部组织中IL-1β含量的影响 被引量:1
1
作者 韩涛 何磊 +1 位作者 李述新 李洪久 《辽宁中医药大学学报》 CAS 2008年第5期169-170,共2页
通过实验观察乙乙乳膏对实验性损伤性血肿局部软组织炎性介质IL-1β的影响及组织形态学改变。方法:通过打击局部建立家兔急性软组织损伤模型,随机分为乙乙乳膏组,阴性对照组,阳性对照组,正常组。除正常组外各组分别应用乙乙乳膏或对照药... 通过实验观察乙乙乳膏对实验性损伤性血肿局部软组织炎性介质IL-1β的影响及组织形态学改变。方法:通过打击局部建立家兔急性软组织损伤模型,随机分为乙乙乳膏组,阴性对照组,阳性对照组,正常组。除正常组外各组分别应用乙乙乳膏或对照药或65%酒精局部给药,于治疗后第1、3、5天同一时相局部软组织取材,部分组织匀浆,用ELISA法测定匀浆液中IL-1β含量,在电镜和光镜下观察组织形态学变化。结果:乙乙乳膏组,扶他林凝胶膏组损伤局部软组织瘀血明显消退,肌纤维的修复;盐水组损伤局部软组织IL-1β的含量伤后各时相明显高于正常组(P<0.01);乙乙乳膏组有效抑制模兔损伤局部组织IL-1β的含量(P<0.01),而与扶他林组比较无显著性差异(P>0.05)。结论:乙乙乳膏剂可以有效的促进损伤局部瘀血的消散和肌纤维的修复,其治疗急性软组织损伤的治疗机理与抑制损伤局部软组织炎性因子IL-1β的产生有关。 展开更多
关键词 软组织损伤 乙乙乳膏 白介素1Β
下载PDF
乙乙乳膏对醋酸所致小鼠致痛模型的影响
2
作者 张昱轩 李洪久 《辽宁中医药大学学报》 CAS 2009年第6期247-248,共2页
目的:观察乙乙乳膏对醋酸所致小鼠疼痛模型的影响。方法:取小鼠48只,随机分为4组各12只,即乙乙乳膏高、低剂量组、空白组和扶他林对照组。将药物涂于小鼠尾部,面积为1cm2,每天给药1次,连续给药7天,空白组只贴乳膏。于第7天所有小鼠腹腔... 目的:观察乙乙乳膏对醋酸所致小鼠疼痛模型的影响。方法:取小鼠48只,随机分为4组各12只,即乙乙乳膏高、低剂量组、空白组和扶他林对照组。将药物涂于小鼠尾部,面积为1cm2,每天给药1次,连续给药7天,空白组只贴乳膏。于第7天所有小鼠腹腔注射0.6%醋酸溶液0.2mL/10g致痛,记录各小鼠出现第1次扭体反应的时间及15min内扭体次数,比较各组扭体次数。结果:乙乙乳膏高、低剂量组平均扭体次数(16.4±8.5)和(19.2±11.4)次,均显著少于空白组(23.4±12.2)。乙乙乳膏各剂量组与扶他林剂量组(15.8±8.6)次比较,扭体次数无显著差异。乙乙乳膏高、低剂量组扭体反应的抑制率分别为29.9%和19.9%。扶他林组扭体反应的抑制率为32.5%。乙乙乳膏组平均扭体次数均较空白组少(均P<0.01)。结论:乙乙乳膏对醋酸所致小鼠疼痛模型有明显的镇痛作用,且镇痛作用与剂量呈量效关系。 展开更多
关键词 乙乙乳膏 小鼠 镇痛作用
下载PDF
Effect of Calcination Temperature on La-Modified Al2O3 Catalysts for Vapor Phase Hydrofluorination of Acetylene to Vinyl Fluoride 被引量:4
3
作者 毕庆员 鲁继青 +2 位作者 邢丽琼 郭明 罗孟飞 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第1期89-94,I0002,共7页
A La-modified Al2O3 catalyst was prepared with deposition-precipitation method. The effect of calcination temperature on the reactivity for vapor phase hydrofluorination of acetylene to vinyl fluoride. The catalysts c... A La-modified Al2O3 catalyst was prepared with deposition-precipitation method. The effect of calcination temperature on the reactivity for vapor phase hydrofluorination of acetylene to vinyl fluoride. The catalysts calcined at different temperatures were characterized using NH3-TPD, pyridine-FTIR, X-ray diffraction, and Raman techniques. It was found that the calcination process could not only change the structure of these catalysts but also modify the amount of surface acidity on the catalysts. The catalyst calcined at 400 ℃ exhibited the highest conversion of acetylene (94.6%) and highest selectivity to vinyl fluoride (83.4%) and lower coke deposition selectivity (0.72%). The highest activity was related to the largest amount of surface acidity on the catalyst, and the coke deposition was also related to the total amount of surface acidic sites. 展开更多
关键词 La2O3-Al2O3 catalyst Hydrofluorination reaction Vinyl fluoride ACETYLENE Calcination temperature
下载PDF
Selective oxidative dehydrogenation of ethane to ethylene over a hydroxylated boron nitride catalyst 被引量:10
4
作者 石磊 闫冰 +3 位作者 邵丹 姜凡 王东琪 陆安慧 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第2期389-395,共7页
Boron nitride containing hydroxyl groups efficiently catalysed oxidative dehydrogenation of ethane to ethylene,offering rather high selectivity(95%) but only small amount of CO2 formation(0.4%) at a given ethane c... Boron nitride containing hydroxyl groups efficiently catalysed oxidative dehydrogenation of ethane to ethylene,offering rather high selectivity(95%) but only small amount of CO2 formation(0.4%) at a given ethane conversion of 11%.Even at high conversion level of 63%,the selectivity of ethylene retained at 80%,which is competitive with the energy-demanding industrialized steam cracking route.A long-term test for 200 h resulted in stable conversion and product selectivity,showing the excellent catalytic stability.Both experimental and computational studies have identified that the hydrogen abstraction of B-OH groups by molecular oxygen dynamically generated the active sites and triggered ethane dehydrogenation. 展开更多
关键词 Boron nitride HYDROXYLATION ETHANE Oxidative dehydrogenation ETHYLENE
下载PDF
Size-controlled preparation of hollow silica spheres and glyphosate release 被引量:6
5
作者 刘纯 殷恒波 +5 位作者 王爱丽 吴占敖 吴刚 姜涛 沈玉堂 姜廷顺 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1161-1168,共8页
Different-sized hollow SiO2 spheres of 249–1348 nm in diameter were successfully prepared by using Na2SiO3 as the precursor and using polystyrene and polystyrene-methyl acrylic acid latexes as the templates. The diam... Different-sized hollow SiO2 spheres of 249–1348 nm in diameter were successfully prepared by using Na2SiO3 as the precursor and using polystyrene and polystyrene-methyl acrylic acid latexes as the templates. The diameter and shell thickness of the hollow SiO2 spheres increase with increasing the latex template diameter at a given mass ratio of SiO2 to latex template. The diameter and shell thickness of the hollow SiO2 spheres also increase with increasing the mass ratios of SiO2 to latex template. The presence of carboxylic acid groups on the surfaces of polystyrene-methyl acrylic acid latex templates favors the formation of dense and uniform SiO2 shells. The hollow SiO2 sphere is constructed by mesoporous shell with large specific surface area. When glyphosate is used as a release model chemical, glyphosate release rate is tuned by varying the shell thickness. 展开更多
关键词 hollow SiO2 sphere POLYSTYRENE polystyrene-methyl acrylic acid glyphosate release
下载PDF
Studies on Chemical Constituents of the Fermentation Liquor of Soil Fungus 07-11 被引量:1
6
作者 张祎 王涛 +2 位作者 裴月湖 华会明 冯宝民 《Journal of Chinese Pharmaceutical Sciences》 CAS 2001年第4期190-192,共3页
Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergo... Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergosta-7,22-diene-3,6-dione (2) respectively on the basis of spectral analyses and physical and chemical identifications. Compound 1 was a new natural product. Compound 2 was firstly isolated from its genus. Spectral data of 1 and complete 1H NMR data of 2 were reported for the first time. 展开更多
关键词 Soil fungi N-(4-hydroxy-2-methoxyphenyl)acetamide Ergosta-7 22-diene-3 6-dione
下载PDF
Direct synthesis of nitrogen-doped mesoporous carbons for acetylene hydrochlorination 被引量:7
7
作者 杨勇 蓝国钧 +1 位作者 王小龙 李瑛 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1242-1248,共7页
Nitrogen‐doped ordered mesoporous carbon (N‐OMC) catalysts were directly synthesized using SBA‐15 as a hard template and sucrose as a carbon source. Urea, which was used as the nitrogen source, was carbonized wit... Nitrogen‐doped ordered mesoporous carbon (N‐OMC) catalysts were directly synthesized using SBA‐15 as a hard template and sucrose as a carbon source. Urea, which was used as the nitrogen source, was carbonized with sucrose. A 3.6 wt% nitrogen doping of the carbon framework was achieved, with more than 70%of the nitrogen incorporated as quaternary nitrogen species. Only 0.2 wt% nitrogen doping, with only 32.7% quaternary nitrogen incorporation was obtained in an N‐OMC catalyst (N‐OMC‐T) prepared using a two‐step post‐synthesis method. The acetylene hy‐drochlorination activities of N‐OMC catalysts prepared via the one‐step method were higher than that of the N‐OMC‐T catalyst because of the higher nitrogen loadings. 展开更多
关键词 ACETYLENE HYDROCHLORINATION Vinyl chloride MERCURY-FREE N-doped carbon
下载PDF
Cloning and Expression Analysis of PtFATB Gene Encoding the Acyl-acyl Carrier Protein Thioesterase in Populus tomentosa Carr 被引量:1
8
作者 周洲 张德强 卢孟柱 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第3期267-274,共8页
Acyl-ACP thioesterases (FATs) terminates the fatty acid synthesis and allow the transport of fatty acids out of the plastids, which are the important determinants of cellular metabolism. FATB is a member of FAT enzy... Acyl-ACP thioesterases (FATs) terminates the fatty acid synthesis and allow the transport of fatty acids out of the plastids, which are the important determinants of cellular metabolism. FATB is a member of FAT enzymes that has been described previously in most of the plants. In silico cloning is a new method that utilizes the bioinformatics on the complete genome and available EST database. In this study, a full-length cDNA clone of PtFATB gene was isolated from Populus tomentosa using this approach. It is 1,450 bp in length and the open reading frame encodes a peptide of 421 amino acids. The predicted amino acid sequence shows significant homology with those from other plant species, which contain typical domains owned by FATB proteins. The transcripts of PtFATB were abundant in leaves, and less in roots detected by using semiquantitative RT-PCR. When the shoots were subjected to the stress treatments (cold, dry, NaC1) and ABA (Abscisic acid), the expression of PtFATB was only slightly reduced under the treatment of low temperature. This suggests that the expression of PtFATB is in a constitutive fashion. This study provides the basis not only for the identification and characterization of this gene but also for the improvement of cold tolerance by controlling the expression of the PtFATB gene in trees in near future. 展开更多
关键词 Populus tomentosa Carr. Acyl-acyl carrier protein thioesterase (PtFATB) in silico and molecular cloning RT-PCR expression analysis
下载PDF
Anticancer Activities of Substituted Cinnamic Acid Phenethyl Esters on Human Cancer Cell Lines 被引量:4
9
作者 李树春 李辉 +2 位作者 张法 李中军 崔景荣 《Journal of Chinese Pharmaceutical Sciences》 CAS 2003年第4期184-187,共4页
Caffeic acid phenethyl ester (CAPE) and sixteen substituted cinnamic acid phenethyl esters were prepared via conventional procedures in order to test their in vitro anticancer activities by either MTT assay or SRB... Caffeic acid phenethyl ester (CAPE) and sixteen substituted cinnamic acid phenethyl esters were prepared via conventional procedures in order to test their in vitro anticancer activities by either MTT assay or SRB assay on six different human cancer cell lines. The results indicated that in the concentration of 10 μmol·L -1 the lead compound CAPE possessed anticancer activities against human HL 60, Bel 7402, and Hela cell lines, and two other compounds possessed potent anticancer activities against Bel 7402 and Hela cell lines. 展开更多
关键词 medicinal chemistry cinnamic acid phenethyl esters chemical synthesis anticancer activity
下载PDF
Enhanced ethanol electro-oxidation on CeO_2-modified Pt/Ni catalysts in alkaline solution 被引量:3
10
作者 徐志花 饶丽霞 +3 位作者 宋海燕 严朝雄 张利君 杨水彬 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第2期305-312,共8页
Pt/Ni catalysts modified with CeO2 nanoparticles were prepared by simple composite electrodeposition of Ni and CeO2,and spontaneous Ni partial replacement by Pt processes.The as-prepared CeO2-modified Pt/Ni catalysts ... Pt/Ni catalysts modified with CeO2 nanoparticles were prepared by simple composite electrodeposition of Ni and CeO2,and spontaneous Ni partial replacement by Pt processes.The as-prepared CeO2-modified Pt/Ni catalysts showed enhanced catalytic performance for ethanol electro-oxidation compared with pure Pt/Ni,and acetate species were proposed to be the main products of the oxidation when using these catalysts.The content of CeO2 in the as-prepared catalysts influenced their catalytic activity,with Pt/NiCe2(obtained from an electrolyte containing 100 mg/L CeO2 nanoparticles) exhibiting higher activity and relatively better stability in ethanol electro-oxidation.This was mainly due to the oxygen storage capacity of CeO2,the interaction between Pt and CeO2/Ni,and the relatively small contact and charge transfer resistances.The results of this work thus suggest that electrocatalysts with low price and high activity can be rationally designed and produced by a simple route for use in direct ethanol fuel cells. 展开更多
关键词 Direct ethanol fuel cell Ethanol oxidation CeO2 nanoparticle Composite electrodeposition ELECTROCATALYST
下载PDF
Structural Characterization and Thermal Properties of 1-Amino-1- ethylamino-2,2-dinitroethylene 被引量:2
11
作者 徐抗震 赵凤起 +3 位作者 王锋 王晗 罗金安 胡荣祖 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第3期335-341,I0002,共8页
1-amino-1-ethylamino-2,2-dinitroethylene (AEFOX-7) was synthesized by the reaction of 1,1- diamino-2,2-dinitroethylene (FOX-7) and ethylamine aqueous solution at 92 ℃. The the- oretical investigation on AEFOX-7 w... 1-amino-1-ethylamino-2,2-dinitroethylene (AEFOX-7) was synthesized by the reaction of 1,1- diamino-2,2-dinitroethylene (FOX-7) and ethylamine aqueous solution at 92 ℃. The the- oretical investigation on AEFOX-7 was carried out by B3LYP/6-311++G^** method. The IR frequencies and NMR chemical shifts were performed and compared with the experimental results. The thermal behavior of AEFOX-7 was studied with differential scanning calorimetry and thermal gravity-derivative thermogravimetry methods, and can be divided into a melting process and an exothermic decomposition process. The enthalpy, apparent activation energy and pre-exponential factor of the exothermic decomposition reaction were obtained as 374.88 kJ/mol, 169.7 kJ/mol, and 10^19.24 s^-1, respectively. The critical temperature of thermal explosion of AEFOX-7 is 145.2 ℃. The specific heat capacity of AEFOX-7 was determined with micro-DSC method and theoretical calculation method, and the molar heat capacity is 214.50 J/(mol K) at 298.15 K. The adiabatic time-to-explosion of AEFOX-7 was calculated to be a certain value between 1.38-1.40 s. The thermal stability of AEFOX-7 is much lower than that of FOX-7. 展开更多
关键词 1-Amino-l-ethylamino-2 2-dinitroethylene 1 1-Diamino-2 2-dinitroethylene Thermal behavior Theoretical calculation Adiabatic time-to-explosion
下载PDF
Dehydration of bio-ethanol to ethylene over iron exchanged HZSM-5 被引量:5
12
作者 陈宝辉 陆佳政 +1 位作者 吴莲萍 晁自胜 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第11期1941-1948,共8页
Iron exchanged ZSM-5 with Si/Al ratio from 25 to 300 prepared by three consecutive ion exchanges was used for the dehydration of ethanol to ethylene.The iron exchanged ZSM-5(Si/Al=25) catalyst with an iron content o... Iron exchanged ZSM-5 with Si/Al ratio from 25 to 300 prepared by three consecutive ion exchanges was used for the dehydration of ethanol to ethylene.The iron exchanged ZSM-5(Si/Al=25) catalyst with an iron content of 0.46 wt%gave 97%-99%yield of ethylene at 98%-99%conversion of ethanol at 260℃ and 0.81 h^-1 liquid hourly space velocity.The high performance was maintained for60 d on-stream.X-ray diffraction,Fourier transform infrared spectroscopy of pyridine adsorption,NH3 temperature-programmed desorption and diffuse reflectance UV-vis spectroscopy were used for catalyst characterization.Ion exchange with iron decreased the total acidity of the zeolite,especially the strong acid sites and Bronsted acid sites.The doped iron species were distributed over Fe-ZSM-5 as predominantly isolated Fe^3+.Therefore,the catalytic performance for ethanol dehydration to ethylene was improved. 展开更多
关键词 IRON ZSM-5 DEHYDRATION Ethanol ETHYLENE
下载PDF
Construction of Deficient Strain by Selenomonas ruminantium Mutant with the Acetic Acid and Analysis on Its Related Enzyme Activity
13
作者 苑学 逄晓阳 +1 位作者 刘国文 王哲 《Agricultural Science & Technology》 CAS 2011年第8期1226-1229,共4页
[Objective]The research aimed to construct deficient strain generated by Selenomonas ruminantium mutant with the acetic acid and analyze its fermentation characteristics.[Method]Based on the transposon tagging method,... [Objective]The research aimed to construct deficient strain generated by Selenomonas ruminantium mutant with the acetic acid and analyze its fermentation characteristics.[Method]Based on the transposon tagging method,Selenomonas ruminantium(recipient strain)was carried out the transposon mutagenesis via the transposon donor strain E.coli S17-1/pZJ25∷Tn5.The zygote was screened by using the selective medium which included kanamycin and sodium fluoroacetate.[Result]Seven transposon engineered strains which had the stable resistance to kanamycin and fluoroethanoic acid were screened.Selenomonas ruminantium mutant was carried out 16S rRNA and Tn5 PCR identification.Moreover,the specific activities of AK and PTA were analyzed.The mutant belonged to fluoroethanoic acid resistance strain with pta gene deficiency.[Conclusion]The research laid the foundation for further studying the cellular metabolic network and regulation of acetic acid in rumen microorganism of ruminant animal. 展开更多
关键词 Selenomonas ruminantium TRANSPOSON PTA AK
下载PDF
Comparative Study of _(99m)TcN(NOEt)_2 and ^(99m)Tc-MIBI Imaging in Mice Bearing Ehrlich Ascites Tumor
14
作者 邢诗安 张永学 安锐 《The Chinese-German Journal of Clinical Oncology》 CAS 2003年第1期45-48,61,共5页
Objective To evaluate and compare the ability to detect tumor by bis (N-ethoxy-N-ethyl dithiocarbamato) nitrido99mTc(V) [99mTcN(NOEt)2] and99mTc hexakis-2- methoxyisobutyl isonitrile [99mTc-MIBI]. Methods 99mTcN(NOE... Objective To evaluate and compare the ability to detect tumor by bis (N-ethoxy-N-ethyl dithiocarbamato) nitrido99mTc(V) [99mTcN(NOEt)2] and99mTc hexakis-2- methoxyisobutyl isonitrile [99mTc-MIBI]. Methods 99mTcN(NOEt)2 was prepared and quality control was performed using ascending thin-layer chromatography. Four mice bearing Ehrich ascites tumor cells underwent whole body planar imaging at 30 min, 2 h and 4 h after injection of99mTc-MIBI or99mTcN(NOEt)2. ROIs were drawn around the tumor, head, chest, and contralateral limbs in whole body planar images, and ratios of radioactivity in tumor in head (T/H), chest (T/C), and contralateral limbs (T/L) were calculated. The mice of99mTcN (NOEt)2 group were killed, then blood was collected, and the tumor and organs were excised, weighed and the radioactivity was measured. Results 99mTcN(NOEt)2 was stable after 4h at the room temperature.99mTcN(NOEt)2 was delivered to the tumor selectively and efficiently.99mTcN(NOEt)2 was found to provide excellent tumor-to-nontumor contrast for all the tissue except the abdomen. The T/L ratios increased to their maximums (4.87) at 2 h after injection. There was significant difference between the99mTcN(NOEt)2 imaging group and99mTc-MIBI imaging group. In vitro the radioactivity ratios per unit weight of tumor to blood, muscle, skeleton, lung, heart, and spleen were much higher than those of tumor to liver, instestine. Conclusion In mice bearing Ehrich ascites tumor,99mTcN(NOEt)2 exhibits a set of features essential for a good tracer for tumor imaging, including a rapid washout from blood, high uptake rate in tumor tissue, prolonged retention and high tumor-to-nontumor uptake ratio. The imaging quality of99mTcN(NOEt)2 was superior to that of99mTc-MIBI. These features indicate that99mTcN(NOEt)2 may be a better tracer to detect tumor than99mTc-MIBI. Key words tumor - radionuclide imaging - NOEt - MIBI 展开更多
关键词 TUMOR radionuclide imaging NOET MIBI
下载PDF
IN-SITU POLYMERIZED SYNTHESIS AND PROPERTIES OF NANO-ZnO/PEG/PET COMPOSITE
15
作者 董祥 陶杰 汪涛 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第4期303-310,共8页
Nano-ZnO particle (nZnOp) reinforced polyethylene glycol (PEG)/polyethylene terephthalate (PET) (nZnOp/PEG/PET) copolymeric composites with different mass fractions and molecular weights of PEG are synthesized... Nano-ZnO particle (nZnOp) reinforced polyethylene glycol (PEG)/polyethylene terephthalate (PET) (nZnOp/PEG/PET) copolymeric composites with different mass fractions and molecular weights of PEG are synthesized via in-situ polymerization. The dispersion of nZnOp in copolymer matrixes and the effects of PEG and nZnOp particles on the crystallization behavior of the composites are studied by TEM, differential scanning calorimetry(DSC), XRD and Fourier thansform infrared spectroscopy (FTIR ). The results reveal that nZnOp particles are dispersed in the matrixes with nano-scale, and the addition of PEG induces more homogeneous dispersion of nZnOp. Simultaneously, these nanoparticles become nucleating centers during the crystallization of the matrixes. PEG segments can improve the flexibility of the PET molecular chain, resulting in the drop of the cold crystallization temperature and the rise of the crystallization rate of the composites. Furthermore, PEG (4 000) with the mass fraction of 10% can promote the crystallization rate of the composites. The mechanical properties show that the nano-particles strengthen and toughen the PET matrix, whereas PEG weakens these improve- ments. 展开更多
关键词 polyethylene terephthalate (PET) polyethylene glycol (PEG) NANO-COMPOSITES nano zinc oxide (ZnO)
下载PDF
Effect of EDTA and NH_4Cl additives on electrodeposition of Zn-Ni films from choline chloride-based ionic liquid 被引量:7
16
作者 S.FASHU 谷长栋 +3 位作者 张嘉磊 黄美玲 王秀丽 涂江平 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第6期2054-2064,共11页
Two additives of ethylene diamine tetraacetic acid (EDTA) and ammonium chloride (NH4C1) were separately used in the electrodeposition of Zn-Ni alloy films from a deep eutectic solvent. The effects of these two add... Two additives of ethylene diamine tetraacetic acid (EDTA) and ammonium chloride (NH4C1) were separately used in the electrodeposition of Zn-Ni alloy films from a deep eutectic solvent. The effects of these two additives on electrodeposition behavior, composition, morphology, and corrosion performance of the Zn-Ni alloys were investigated. The electrodeposition behaviors of Zn-Ni alloy revealed by the cyclic voltammetry show that the addition of EDTA to the Zn-Ni electrolyte enhances the Zn incorporation into the alloy film while the addition of NH4C1 produces an opposite effect by suppressing Zn incorporation into the film. With an increase of EDTA concentration in the electrolyte, the Zn content of the Zn-Ni films increases, while the grain size of the deposits and the current efficiency of the plating process decrease. The increase of NH4C1 concentration in the electrolyte would significantly refine the grain size of the electrodeposited Zn-Ni films, reduce the Zn content and increase the cathodic current efficiency. The corrosion testing indicates that the barrier corrosion resistances of Zn-Ni films electrodeposited from NHnC1 containing electrolytes are superior to those electrodeposited from EDTA-containing electrolytes, which in turn are superior to those electrodeposited from additive-free electrolytes. 展开更多
关键词 ADDITIVE EDTA NH4C1 deep eutectic solvent corrosion resistance
下载PDF
Effect of IB-metal on Ni/SiO2 catalyst for selective hydrogenation of acetylene 被引量:9
17
作者 Hua Liu Mengqian Chai +5 位作者 Guangxian Pei Xiaoyan Liu Lin Li Leilei Kang Aiqin Wang Tao Zhang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第7期1099-1108,共10页
The IB metal(Au,Ag and Cu)alloyed Pd single atom catalysts had been proved to be efficient in promoting the selectivity for hydrogenation of acetylene to ethylene.As a base metal in the same group as Pd,the Ni-based c... The IB metal(Au,Ag and Cu)alloyed Pd single atom catalysts had been proved to be efficient in promoting the selectivity for hydrogenation of acetylene to ethylene.As a base metal in the same group as Pd,the Ni-based catalysts are also active for hydrogenation reactions.Herein,the effects of the IB metals on the Ni/SiO2 catalyst for the selective hydrogenation of acetylene were systematically studied.Different from the Pd/SiO2 catalyst,the monometallic Ni/SiO2 catalyst is not active at low temperatures.The addition of the IB metals to the Ni/SiO2 catalysts can greatly enhance the activity.Besides,the catalytic activity of the AuNix/SiO2 and CuNix/SiO2 catalysts increase with the reduction temperature,while the AgNix/SiO2 catalysts are not sensitive to the pretreatment temperature.The origin of the effect of the different IB metals on the Ni-based catalysts for selective hydrogenation of acetylene is discussed based on the characterizations by XRD,TPR and microcalorimetric measurements. 展开更多
关键词 ACETYLENE Selective hydrogenation ETHYLENE Ni IB metals
下载PDF
Systematic review and meta-analysis of colon cleansing preparations in patients with inflammatory bowel disease 被引量:17
18
作者 Sophie Restellini Omar Kherad +5 位作者 Talat Bessissow Charles Ménard Myriam Martel Maryam Taheri Tanjani Peter L Lakatos Alan N Barkun 《World Journal of Gastroenterology》 SCIE CAS 2017年第32期5994-6002,共9页
AIM To performed a systematic review and meta-analysis to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon-cleansing products in patients with inflammatory b... AIM To performed a systematic review and meta-analysis to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon-cleansing products in patients with inflammatory bowel disease.METHODS Systematic searches were performed( January 1980-September 2016) using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge for randomized trials assessing preparations with or without adjuvants, given in split and non-split dosing, and in high(> 3 L) or low-volume(2 L or less) regimens. Bowel cleansing quality was the primary outcome. Secondary outcomes included patient willingness-torepeat the procedure and side effects/complications.RESULTS Out of 439 citations, 4 trials fulfilled our inclusion criteria(n = 449 patients). One trial assessed the impact of adding simethicone to polyethylene glycol(PEG) 4 L with no effect on bowel cleansing quality, but a better tolerance. Another trial compared senna to castor oil, again without any differences in term of bowel cleansing. Two trials compared the efficacy of PEG high-volume vs PEG low-volume associated to an adjuvant in split-dose regimens: PEG low-dose efficacy was not different to PEG high-dose; OR = 0.84(0.37-1.92). A higher proportion of patients were willing to repeat low-volume preparations vs high-volume; OR = 5.11(1.31-20.0). CONCLUSION In inflammatory bowel disease population, PEG lowvolume regimen seems not inferior to PEG high-volume to clean the colon, and yields improved willingness-torepeat. Further additional research is urgently required to compare contemporary products in this population. 展开更多
关键词 Inflammatory bowel disease Polyethylene glycol COLONOSCOPY META-ANALYSIS
下载PDF
Experimental study of partially decoupled oxidation of ethane for producing ethylene and acetylene 被引量:2
19
作者 Jiajia Luo Jinfu Wang Tiefeng Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第6期1312-1320,共9页
With increasing amount of unconventional natural gas,the production of ethane,propane and other low alkanes continues to increase.In our previous works,a partially decoupled process(PDP) was proposed for conversion of... With increasing amount of unconventional natural gas,the production of ethane,propane and other low alkanes continues to increase.In our previous works,a partially decoupled process(PDP) was proposed for conversion of ethane based on numerical simulations,which showed higher acetylene and ethylene selectivities than the original partial oxidation process.In the current work,the PDP of ethane for producing acetylene and ethylene was studied experimentally to verify the PDP concept.In the PDP of ethane,coke-oven gas or other cheap gas combusts with stoichiometric oxygen as heat carrier,and ethane is mixed with the heat carrier and undergoes pyrolysis at high temperatures.The jet-in-cross-flow(JICF) reactor was designed and manufactured to realize the PDP.A positioning device of 0.1 mm accuracy and a mass spectrometer were used to measure the spatial profiles of the species concentrations.The maximum combined yield(52.7%) of acetylene and ethylene was obtained even at the condition of heat loss,confirming that the PDP of ethane was advantageous over the partial oxidation process and at least comparable to the steam cracking process. 展开更多
关键词 Partial oxidation Experimental validation Pyrolysis Ethane conversion Partially decoupled process(PDP) Jet-in-cross-flow(JICF) reactor
下载PDF
Ethyl and butyl acetate oxidation over manganese oxides 被引量:2
20
作者 Olívia Salomé G.P.Soares Raquel P.Rocha +2 位作者 Jose J.M.Orfao Manuel F.R.Pereira José L.Figueiredo 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第1期27-36,共10页
Mangenese oxides were synthesized using two new methods,a novel solvent‐free reaction and a reflux technique,that produced cryptomelane‐type products(K‐OMS‐2).Oxides were also synthesized using conventional method... Mangenese oxides were synthesized using two new methods,a novel solvent‐free reaction and a reflux technique,that produced cryptomelane‐type products(K‐OMS‐2).Oxides were also synthesized using conventional methods and all specimens were applied to the oxidation of ethyl acetate and butyl acetate,acting as models for the volatile organic compounds found in industrial emissions.The catalysts were also characterized using N2adsorption,X‐ray diffraction,scanning electron microscopy,temperature programmed reduction and X‐ray photoelectron spectroscopy.Each of the manganese oxides was found to be very active during the oxidation of both esters to CO2,and the synthesis methodology evidently had a significant impact on catalytic performance.The K‐OMS‐2nanorods synthesized by the solvent‐free method showed higher activity than K‐OMS‐2materials prepared by the reflux technique,and samples with cryptomelane were more active than those prepared by the conventional methods.The catalyst with the highest performance also exhibited good stability and allowed90%conversion of ethyl and butyl acetate to CO2at213and202°C,respectively.Significant differences in the catalyst performance were observed,clearly indicating that K‐OMS‐2nanorods prepared by the solvent‐free reaction were better catalysts for the selected VOC oxidations than the mixtures of manganese oxides traditionally obtained with conventional synthesis methods.The superior performance of the K‐OMS‐2catalysts might be related to the increased average oxidation state of the manganese in these structures.Significant correlations between the catalytic performance and the surface chemical properties were also identified,hig-hlighting the K‐OMS‐2properties associated with the enhanced catalytic performance of the materials.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved. 展开更多
关键词 Volatile organic compound Ethyl acetate Butyl acetate Manganese oxide Catalytic oxidation
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部