检索结果-南通市图书馆

Enhanced performance for propane dehydrogenation through Pt clusters alloying with copper in zeolite

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第5期16卷 6537-6543页

作者： Jie Zhou Ying Zhang Hao Liu Chao Xiong Peng Hu Hao Wang Shenwei Chen Hongbing Ji Fine Chemical Industry Research Institute School of ChemistrySun Yat-sen UniversityGuangzhou 510275China Huizhou Research Institute Sun Yat-sen UniversityHuizhou 516081China College of Chemical Engineering State Key Laboratory Breeding Base of Green Chemistry-Synthesis TechnologyZhejiang University of TechnologyHangzhou 310014China

Metal alloys have been widely applied for heterogeneous catalysis,especially alkane ***,the catalysts always suffer from sintering and coke deposition due to the rigorous reaction ***,we described an original approach to prepare a catalyst where highly dispersed Pt clusters alloying with copper were encapsulated in silicalite-1(S-1)zeolite for propane dehydrogenation(PDH).The introduction of Cu species significantly enhances the catalytic activity and prolongs the lifetime of the catalyst.0.1Pt0.4CuK@S-1 exhibits a propane conversion of 24.8%with 98.2%selectivity of propene,and the specific activity of propylene formation is up to 32 mol·gPt^(−1)·h^(−1)at 500℃.No obvious deactivation is observed even after 73 h on stream,affording an extremely low deactivation constant of 0.00032 h^(−1).The excellent activity and stability are ascribed to the confinement of zeolites and the stabilization of Cu species for Pt clusters.

关键词： Highly dispersed Pt clusters silicalite-1(S-1)zeolite propane dehydrogenation specific activity low deactivation constant

Fishbone-like platinum-nickel nanowires as an efficient electrocatalyst for methanol oxidation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2020年第1期13卷 67-71页

作者： Jinquan Chang Luting Song Yuanqing Xu Yanhong Ma Cheng Liang Wenyu Jiang Yong Zhang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Platinum(Pt)-based electrocatalyst with low Pt content and high electrocatalytic performance is highly desired in fuel cell ***,we demonstrated that platinum-nickel(Pt-Ni)nanowires with an average composition of PtNi3 and a fishbone structure can be readily synthesized and used as an efficient electrocatalyst toward methanol oxidation reaction(MOR).The PtNi3 fishbone-like nanowires(PtNi3-FBNWs)present features such as richer Pt on the surface than in the bulk,high-index facets on the rough surface,and polyhedral facets at the ends of side *** compositional and structural features could be determinative to the enhanced performance in the electrocatalysis of *** with commercial 20%Pt/carbon black(Pt/C),the specific activity and mass activity of the PtNi3-FBNWs are enhanced by approximately 4.76 and 3.02 times,*** stability of electrocatalysis is significantly improved as *** comprehensive enhancement indicates that the PtNi3-FBNWs would be a promising candidate toward MOR in fuel cells.

关键词： Pt-Ni nanowires(NWs) electrocatalysis specific activity mass activity methanol oxidation reaction(MOR)

Analysis of radiation environmental safety for China's Spallation Neutron Source (CSNS)

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2010年第7期34卷 1029-1036页

作者：王庆斌吴青彪马忠剑张清江李楠吴靖民刘剑张刚 Institute of High Energy Physics CAS

The China Spallation Neutron Source（CSNS） is going to be located in Dalang Town,Dongguan City in the Guangdong *** this paper we report the results of the parameters related with environment safety based on experiential calculations and Monte Carlo *** main project of the accelerator is an under ground *** top there is a 0.5 m concrete and 5.0 m soil covering for shielding,which can reduce the dose out of the tunnel＇s top down to 0.2 μSv/*** the residents on the boundary of the CSNS,the dose produced by skyshine,which is caused by the penetrated radiation leaking from the top of the accelerator,is no more than 0.68 μSv/*** CSNS is operating normally,the maximal annual effective dose due to the emission of gas from the tunnel is 2.40×10-3 mSv/a to the public adult,and 2.29×10-3 mSv/a to a child,both values are two orders of magnitude less than the limiting value for control and *** may give rise to an activation of the soil and groundwater in the nearest tunnels,where the main productions are 3H,7Be,22Na,54Mn,*** the specific activity is less than the exempt specific activity in the national standard *** it is safe to say that the environmental impact caused by the activation of soil and groundwater is *** sum up,for CSNS,as a powerful neutron source device,driven by a highenergy high-current proton accelerator,a lot of potential factors affecting the environment ***,as long as effective shieldings for protection are adopted and strict rules are drafted,the environmental impact can be kept under control within the limits of the national standard.

关键词： China Spallation Neutron Source environmental safety effective dose specific activity

An ultra-highly active nanozyme of Fe,N co-doped ultrathin hollow carbon framework for antibacterial application

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第3期34卷 388-391页

作者： Jinyu Hao Cui Zhang Chenxi Feng Qian Wang Zhong-Yi Liu Yan Li Jianshuai Mu En-Cui Yang Yan Wang College of Chemistry Tianjin Key Laboratory of Structure and Performance for Functional MoleculesTianjin Normal UniversityTianjin 300387China School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China School of food and Bioengineering Xuzhou University of TechnologyXuzhou 221018China

In recent years, nanozymes have received more and more attention, but the low activity limits the development of nanozymes. Therefore, the design and development of efficient nanozymes is still a major challenge for researchers. Herein, the Fe,N co-doped ultrathin hollow carbon framework(Fe,N-UHCF) exhibit ultra-high peroxidase-like activity. The specific activity of Fe,N-UHCF nanozyme is as high as 36.6 U/mg,which is much higher than almost all of other reported nanozymes. In practical applications, the Fe,N-UHCF show good antibacterial effects.

关键词： Peroxidase-like Nanozyme Ultra-highly active specific activity Antibacterial

Nondestructive high-sensitivity measurement method for activation estimation in accelerator room concrete

在线全文

学校读者我要写书评

暂无评论

辐射防护 2020年第6期40卷 677-682页

作者： Hiroshi Matsumura Go Yoshida Akihiro Toyoda Kazuyoshi Masumoto Hajime Nakamura Taichi Miura Koichi Nishikawa Kotaro Bessho Kimikazu Sasa Tetsuaki Moriguchi Fumiyoshi Nobuhara Yoko Nagashima High Energy Accelerator Research Organization(KEK) Oho 1-1Tsukuba Ibaraki 305-0801Japan University of Tsukuba 1-1-1 TennodaiTsukubaIbaraki 305-8577Japan Tokyo Nuclear Services Co. Ltd.1-3-5.TaitoTaito-kuTokyo 110-0016Japan

This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an *** propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation *** this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron *** obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated *** method is a powerful long-term prediction tool for concrete activation.

关键词： accelerator activation concrete specific activity decommissioning

Studies on Properties of Lipase Produced from Aspergillus sp. Isolated from Compost Soil

在线全文

学校读者我要写书评

暂无评论

Advances in Enzyme Research 2022年第2期10卷 49-60页

作者： Chijioke O. Ezenwelu Oladejo A. Afeez Obiano U. Anthony Okoro A. Promise Ude-Ezika C. Mmesoma Oparaji E. Henry Department of Applied Biochemistry Nnamdi Azikiwe University Awka Anambra State Nigeria Department of Chemical Sciences Spiritan University Nneochi Abia State Nigeria

Lipase producing Aspergillus was isolated from soil collected from a refuse dump site located at Awka, Anambra State, Nigeria using standard microbiology and biochemical techniques. Crude extract of lipase was produced after a successful screening of the isolates using mineral broth containing p-NPP through submerged fermentation system with optimized physiologic conditions. Three steps of purification were carried out: Ammonium sulphate, dialysis and gel filtration (sephadex G-150). Crude extract was precipitated by using 70% saturation of ammonium sulphate at pH 6.0 which gave the optimum precipitation of the protein with specific activity of 260.56 U/mg. Precipitation using ammonium sulphate carried out at pH 6.5 and 8.0 gave specific activity of 217 U/mg of the protein. The precipitates were further desalted through dialysis for twelve hours and specific activity of 343.20 U/mg was recorded from the dialysate afterwards. Further purification was done by using sephadex G-150 and specific activity of 490.55 U/mg was recorded from the active pooled fractions. The purification table showed a 2.32 purification folds of lipase was gotten after gel filtration (sephadex G-150) with a lipase percentage yield of 2.00%. The specific activity of lipase increased from 211.81 to 490.55 U/mg. Characterization of β-galactosidase gave optima pH and temperature of the enzyme at 6.0 and 60°C respectively. Kinetic constants: Km and Vmax values were obtained at various concentrations of p-NPP where 0.32 mM and Vmax of 200.00 μmol/min respectively. Ca2+ and Co2+ showed greater effect on lipase activity in a concentration-dependent manner (0.03 - 0.05 M) when compared to Mn2+ and Fe2+. The results from this study have shown that lipase produced from filamentous Aspergillus has a wide range of activity over physiologic conditions in regards to industrial and clinical standard operational procedures.

关键词： Lipase Purification specific activity Precipitation Purification Folds

应用洁消精处理输液瓶及注射器方法的两点改进

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

苏州医学院学报 1994年第3期 179+194-179+194页

作者：施瑞兰朱江江苏省沐阳县人民医院供应室

应用洁消精处理输液瓶及注射器方法的两点改进江苏省沐阳县人民医院供应室施瑞兰，朱江我院自１９９２年４月起应用苏州吴县化工二厂生产的佳乐牌洁消精，按傅仁惠报道的方法［１］处理、浸泡医疗玻璃瓶、器，效果很好，但发现有些瓶、... 详细信息

应用洁消精处理输液瓶及注射器方法的两点改进江苏省沐阳县人民医院供应室施瑞兰，朱江我院自１９９２年４月起应用苏州吴县化工二厂生产的佳乐牌洁消精，按傅仁惠报道的方法［１］处理、浸泡医疗玻璃瓶、器，效果很好，但发现有些瓶、器在再经高压消毒时，发生自然碎裂．...

关键词： colony stimulating factor (CSF)) separation procedures limited dilution culture specific activity