检索结果-南通市图书馆

Chinese Chemical Letters 2011年第11期22卷 1269-1272页

作者： Shen Luan Yu Yan Yun Li Zhen Rong Dong Juan Ni zhang qi Li jing Xing Gao State Key Laboratory of Physical Chemistry of Solid Surfaces National Engineering Laboratory for Green ChemicalProductions of Alcohols-Ethers-Esters and Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China

Novel chiral PN_4-type multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis（o-formylphenyl）phenylphosphane and various chiral *** structures were fully characterized by IR,EI-MS and *** catalytic systems,prepared in situ from the multidentate ligands and iridium（I） complexes,showed high activity in asymmetric transfer hydrogenation of propiophenone in 2-propanol solution,leading to corresponding optical alcohol with up to 75%ee.

关键词： Chiral multidentate aminophosphine ligand Iridium complex Propiophenone Asymmetric transfer hydrogenation

Studies on Antimicrobial Resistance Transfer In vitro and Existent Selectivity of Avian Antimicrobial-Resistant Enterobacteriaccae In vivo

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2008年第5期7卷 636-640页

作者： SONG Li NING Yi-bao zhang qi-jing YANG Cheng-hua GAO Guang HAN Jian-feng China institute of Veterinary Drug Control Beijing 100081 P.R.China College of Veterinary Medicine lowa State University lowa 50011-1250 USA

Increasing antimicrobial resistance （AR） has become a severe problem of public health in the world, whereas control of the AR of bacteria will be based on investigation of the AR mechanism. Furthermore, understanding the existent selectivity of AR organisms from animals can prevent the emergence and diffusion of AR effectively. PCR amplifications of gyrA and parC genes have been performed for detecting fluoroquinolones-resistance （FR） genes. A conjugational transfer test has been carried out using a donor which is resistant to tetracycline （TE）, ampicillin （AMP）, sulfamethoxazole-trimethoprim （SXT）, and a recipient which is sensitive to TE, AMP, and SXT. The AR strains have been passed 20 passages. Two groups of chicken inoculated multi-AR Escherichia coli （E. coli） and multi-AR Salmonella, respectively, are mix-fed. The result shows that amino acid codons of Ser-83 and Asp-87 are mutations from gyrA and there are no mutations from parC genes in all the FR strains. Resistance to TE, AM, and SXT can transfer among E. coli and the conjugal transfer frequency of TE is 3×10^-7. AR can inherit in 20 passages at least. The multi-AR E. coli and Salmonella can be isolated from all chickens three days after inoculation but CIP-resistant strains decrease during the time run out and disappear at 23 days after inoculation. The results indicate that the mutations of gene gyrA are correlative with the FR phenotype. AR genes that are not connected to the chromosome can transfer horizontally and vertically. AR bacteria can diffuse quickly and eliminate naturally from the host if the chicken is not under the pressure of this antibiotic.

关键词： antimicrobial-resistance transfer in vitro enterobacteriaccae diffusion elimination

基于单颗粒电感耦合等离子体质谱技术的金纳米颗粒准确测定和表征

在线全文

学校读者我要写书评

暂无评论

分析化学 2020年第7期48卷 946-954页

作者：巢静波王静如张靖其中国计量科学研究院化学所北京化工大学化学工程学院

建立了基于单颗粒电感耦合等离子体质谱(SP-ICP-MS)技术的金纳米颗粒(AuNPs)数量浓度和粒径的准确测定方法,考察了传输效率计算方式、驻留时间、稀释试剂、进样方式等对测定结果的影响。传输效率对结果准确度影响较大,应根据测量目标参... 详细信息

建立了基于单颗粒电感耦合等离子体质谱(SP-ICP-MS)技术的金纳米颗粒(AuNPs)数量浓度和粒径的准确测定方法,考察了传输效率计算方式、驻留时间、稀释试剂、进样方式等对测定结果的影响。传输效率对结果准确度影响较大,应根据测量目标参数选择传输效率计算方式,并在测定过程中保持传输效率的稳定,利用校准标准对其进行校正。驻留时间的选择直接影响结果的精确程度,应根据样品类型、粒径等性质慎重选择数据处理模式。当驻留时间为0.1 ms时,检测30 nm和60 nm AuNPs的线性范围分别为2～40 pg/g和10～200 pg/g,线性相关系数大于0.9998,数量浓度测定结果的相对标准偏差小于3.80%,颗粒数量浓度和粒径的检出限分别为110 NPs/g和9 nm。对合成的4种AuNPs和国际比对样品分别进行了测定,国际比对样品颗粒数量浓度结果与比对参考值偏差<5%,测定结果等效一致,扩展不确定度<15%(k=2),进一步验证了本方法的准确度和适用性。

关键词：颗粒数量浓度粒径金纳米颗粒单颗粒-电感耦合等离子体质谱法

基于专利分析的3D生物打印产业发展态势研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国生物工程杂志 2022年第6期42卷 102-115页

作者：张景琦王晟杭州电子科技大学图书馆杭州310018 浙江省医学信息与生物三维打印重点实验室杭州310018

目的:揭示3D生物打印产业技术研发态势和专利布局,以期为相关机构提供竞争情报,为行业发展提供数据支撑。方法:基于3D生物打印领域产业调研和技术分解,构造检索式获取数据,多维度量化分析领域专利。结果:3D生物打印产业发展可分为孕育... 详细信息

目的:揭示3D生物打印产业技术研发态势和专利布局,以期为相关机构提供竞争情报,为行业发展提供数据支撑。方法:基于3D生物打印领域产业调研和技术分解,构造检索式获取数据,多维度量化分析领域专利。结果:3D生物打印产业发展可分为孕育期、萌芽期和高速发展期;该产业集中度较低,处于分散竞争阶段;申请人多依据地缘因素选择合作对象,合作方之间多为不同类型的机构;中国申请人的专利申请量占全球的比重已接近50%,但美国申请人的专利篇均被引频次仍远超中国;美国申请人更关注海外市场。结论:3D生物打印产业尚未形成规模效应,有必要整合业内资源,打造产业集群;中、美两国在该产业都具有优势地位,中国亟待加强海外专利布局;综合权衡专利数量和质量,美国申请人的专利竞争力仍高于中国,中国需培育更多核心专利。

关键词： 3D生物打印细胞打印专利分析知识产权信息服务

基于固定股利支付比率的企业盈余可持续性优化模型及实证

在线全文

学校读者我要写书评

暂无评论

系统工程理论与实践 2012年第8期32卷 1673-1680页

作者：张景奇孟卫东重庆大学经济与工商管理学院重庆400044

借助Ohlson模型中股票内在价值与会计信息之间准确的数学逻辑关系,假定企业按利润大小的固定比率支付给股东股利,在借鉴Kormendi和Lipe盈余可持续模型的基础上,运用Ohlson模型对Kormendi和Lipe的盈余可持续模型进行了优化,并构建出了更... 详细信息

借助Ohlson模型中股票内在价值与会计信息之间准确的数学逻辑关系,假定企业按利润大小的固定比率支付给股东股利,在借鉴Kormendi和Lipe盈余可持续模型的基础上,运用Ohlson模型对Kormendi和Lipe的盈余可持续模型进行了优化,并构建出了更符合现实条件的盈余可持续性指标模型.接着,对求得的盈余可持续性指标和Kormendi和Lipe的盈余可持续性指标的有用性进行了比较性的实证检验.我国34家上市公司的意外盈余反应系数的实证分析表明:所求的盈余可持续性优化模型对我国上市公司的盈余反应系数具有更强的相关性,从而进一步证明了该模型更符合现实假设之下的盈余可持续性模型的有用性.

关键词：盈余可持续性优化模型盈余反应系数固定比率股利

在线全文

学校读者我要写书评

暂无评论

浅析外币流动性风险对商业银行经营的影响

上海金融 2009年第5期 85-87页

作者：张琦蒋静中国外汇交易中心

外币流动性风险是商业银行外汇经营过程中面临的最主要的风险之一。近年来,随着人民币对美元汇率持续走强,我国商业银行外币贷款增长偏快,增加了外币流动性风险。本文就商业银行外币流动性风险形成原因、影响因素和外币流动性风险对商... 详细信息

外币流动性风险是商业银行外汇经营过程中面临的最主要的风险之一。近年来,随着人民币对美元汇率持续走强,我国商业银行外币贷款增长偏快,增加了外币流动性风险。本文就商业银行外币流动性风险形成原因、影响因素和外币流动性风险对商业银行经营的影响作了分析,并对商业银行外币流动性风险管理提出了相关的建议。

关键词：外币流动性风险商业银行经营风险管理

Highly conductive and stable iodine doped argyrodite electrolyte for all-solid-state lithium batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 50-58页

作者： Gaozhan Liu jing zhang jing Yang jinghui Chen Xingyue Xiao Xiayin Yao Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

Lithium argyrodites with high ionic conductivity and low cost are considered as one of the most prospective solid electrolytes for all-solid-state lithium ***,the poor chemical stability and compatibility with lithium metal limit their ***,Li5.4PS4.4Cl1.4I0.2solid electrolyte with high ionic conductivity of 11.49 m S cm-1and improved chemical stability is synthesized by iodine *** ultra-thin Li5.4PS4.4Cl1.4I0.2membrane with thickness of 10μm can be obtained by wet coating process,exhibiting a high ionic conductivity of 2.09 mS cm-1and low areal resistance of 1.17Ω***,iodine doping could in-situ form LiI at the lithium/electrolyte interface and improve the critical current density of Li5.4PS4.4Cl1.6from 0.8 to 1.35 mA *** resultant LiCoO2/Li5.4PS4.4Cl1.4I0.2/Li battery shows excellent cycling stability at 1 C,with a reversible specific capacity of 110.1 mA h g-1and a retention of 80.5% after 1000 *** addition,the assembled LiCoO2/Li5.4PS4.4Cl1.4I0.2membrane/Li pouch cell delivers an initial discharge capacity of 110.4 mA h g-1and 80.5% capacity retention after 100 cycles.

关键词： Solid-State Batteries

Dielectric-ion-conductive ZnNb2O6 layer enabling rapid desolvation and diffusion for dendrite-free Zn metal batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 693-701页

作者： Haifeng Yang Jian Wang Panpan zhang Xiaomin Cheng qinghua Guan jing Dong Bixian Chen Lujie Jia jing zhang Yongzheng zhang Yunjian Liu Hongzhen Lin School of Materials Science and Engineering Jiangsu University i-Lab & CAS Key Laboratory of Nanophotonic Materials and Devices Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Helmholtz Institute Ulm (HIU) Karlsruhe Institute of Technology (KIT) School of Materials Science and Engineering Xi'an University of Technology State Key Laboratory of Chemical Engineering East China University of Science and Technology

Rechargeable aqueous zinc-metal batteries （AZMBs） are promising candidates for large-scale energy storage systems due to their low cost and high ***,their performance and sustainability are significantly hindered by the sluggish desolvation kinetics at the electrode/electrolyte interface and the corresponding hydrogen evolution reaction where active water molecules tightly participate in the Zn（H2O）62+solvation ***,learnt from self-generated solid electrolyte interphase （SEI） in anodes,the dielectric but ion-conductive zinc niobate nanoparticles artificial layer is constructed on metallic Zn surface （ZNB@Zn）,acting as a rapid desolvation *** zincophilic and dielectric-conductive properties of ZNB layer accelerate interfacial desolvation/diffusion and suppress surface corrosion or dendrite formation,achieving uniform Zn plating/stripping behavior,as confirmed by electronic/optical microscopies and interface spectroscopical measurements together with theoretical ***,the as-prepared ZNB@Zn electrode exhibits excellent cycling stability of over 2000 h and robust reversibility （99.54%） even under high current density and depth of discharge ***,the assembled ZNB@Zn-based full cell displays high capacity-retention rate of 80.21%after 3000 cycles at 5 A g-1and outstanding rate performance up to 10 A *** large-areal pouch cell is stabilized for hundreds of cycles,highlighting the bright prospects of the dielectric but ion-conductive layer in further application of AZMBs.

关键词： Zn metal battery Dielectric artificial layer Rapid ion diffusion Zincophilic diffusion Active water inhibition

Ammonia pyrolysis oxidation excited by nanosecond pulsed discharge:Global/fluid models hybrid solution

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 385-396页

作者： Mingming zhang Hanyu Wu qi Chen Jiaxin Yang Bonan Liu School of Mechanical Electronic and Control Engineering Beijing Jiaotong University China University of Petroleum

The kinetic characteristics of plasma-assisted oxidative pyrolysis of ammonia are studied by using the global/fluid models hybrid solution ***,the stable products of plasma-assisted oxidative pyrolysis of ammonia are *** results show that the consumption of NH3/O2and the production of N2/H2change linearly with the increase of voltage,which indicates the decoupling of nonequilibrium molecular excitation and oxidative pyrolysis of ammonia at low ***,the detailed reaction kinetics mechanism of ammonia oxidative pyrolysis stimulated by a nanosecond pulse voltage at low pressure and room temperature is *** on the reaction path analysis,the simplified mechanism is *** detailed and simplified mechanism simulation results are compared with experimental data to verify the accuracy of the simplified ***,based on the simplified mechanism,the fluid model of ammonia oxidative pyrolysis stimulated by the nanosecond pulse plasma is established to study the pre-sheath/sheath behavior and the resultant consumption and formation of key *** results show that the generation,development,and propagation of the pre-sheath have a great influence on the formation and consumption of *** consumption of NH3by the cathode pre-sheath is greater than that by the anode pre-sheath,but the opposite is true for OH and O（1S）.However,within the sheath,almost all reactions do not ***,by changing the parameters of nanosecond pulse power supply voltage,it is found that the electron number density,electron current density,and applied peak voltages are not the direct reasons for the structural changes of the sheath and ***,the discharge interval has little effect on the sheath structure and gas mixture *** research results of this paper not only help to understand the kinetic promotion of non-equilibrium excitation in the process of oxidative pyrolysis but also help to explore th

关键词： Nanosecond pulsed discharge Ammonia Oxidative pyrolysis Fluid model Global model

基于微观结构非均匀性理解非晶态聚苯乙烯的应力松弛行为

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

物理学报 2024年第3期73卷 258-265页

作者：张婧祺郝奇吕国建熊必金乔吉超西北工业大学伦敦玛丽女王工程学院西安710072 西北工业大学力学与土木建筑学院西安710072 华中科技大学化学与化工学院武汉430074

研究了非晶态聚苯乙烯材料应力松弛行为与其固有微观结构非均匀性之间的关联,从基本Maxwell黏弹性模型出发,到三参量扩展指数方程,讨论了变形单元特征时间的分布本质及聚合物应力松弛过程中的链段效应.结果表明,非晶态聚苯乙烯应力松弛... 详细信息

研究了非晶态聚苯乙烯材料应力松弛行为与其固有微观结构非均匀性之间的关联,从基本Maxwell黏弹性模型出发,到三参量扩展指数方程,讨论了变形单元特征时间的分布本质及聚合物应力松弛过程中的链段效应.结果表明,非晶态聚苯乙烯应力松弛行为呈现典型非指数特征,单一特征时间的指数衰减形式与有限特征时间的有限谱方法均无法合理描述聚苯乙烯应力松弛行为,这是由于非晶态聚合物微观结构非均匀性所导致的特征时间谱连续分布.此外,本文进一步探究了物理老化导致的应力松弛行为变化,老化导致体系向更稳定能量状态迁移,变形单元难以激活,因而导致应力松弛过程慢化,特征时间延长.

关键词：聚苯乙烯应力松弛黏弹性微观结构非均匀性

维普期刊数据库博看期刊