检索结果-南通市图书馆

维普期刊数据库

Nanostructured bimetallic Zn/Co in N-doped carbon as an efficient catalyst for the alcohol dehydrogenation to carboxylic acids under solvent-free conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第30期161卷 111-122页

作者： Zhong-Hui Zheng Somboon Chaemchuen Jun-Fei Gu Jing Hang Wei Sang Ji-chao Wang Ye yuan cheng Chen State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

The catalytic alcohol dehydrogenation to carboxylic acids has been demonstrated as an atom-economic and environmental-friendly synthetic ***,the reported catalysts either require relatively complicated synthesis or exhibit high activity only in the presence of a ***,it is still in high demand to obtain catalysts that feature facile synthesis and perform well even without any ***,a series of nanostructured bimetallic Zn/Co species embedded in N-doped hierarchical porous carbon were fabricated in a facile and green *** significantly,the best-performing material(Zn/Co@NC-800)was identified as the first heterogeneous catalyst to enable this transformation under solvent-free ***,the as-prepared composites were comprehensively investigated to de-termine their structural and morphological properties,which rationalized the superiority of Zn/Co@NC-800 over the other synthesized *** studies signified that Co sites(both Co^(0)and Co^(2+))and N species(mainly pyridinic N)were probably involved in this process,functioning as the Lewis acid site and basic site,***,this study could provide a simple and sustainable method for carboxylic acid synthesis.

关键词： Heterogeneous catalysis Bimetallic ZIFs Pyrolysis Solvent-free Alcohol dehydrogenation Carboxylic acids

EXTRACTION OF ANTHRAQUINONE DERIVATIVES FROM RHUBARB RHIZOMES AND THEIR ANTIBACTERIAL TESTS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2011年第2期4卷 127-132页

作者： yuan-cheng CAO yuan-DI ZHAO College of Life Science and Technology Huazhong University of Science and Technology Wuhan HuBeiP.R.China430074

Photometry was employed to study the optimum extraction conditions of anthraquinone derivatives from rhizomes of Rheum officinale Baill in this *** influences of extraction solvents(chloroform,benzene,ethanol,methanol,and glycerol),acid,and extraction time on the extraction yield were *** results indicate that,to the Rhubarb rhizomes powder with the average particle size 0.18 mm,the conditions of the extraction solvent composed by chloroform,glycerol,and sulfuric acid(20%)in the ratio of 4:1:1(v:v),the weight of dried Rhubarb to the solvent volume in the ratio of 1:12 ew:vT,extraction time of 110 min,the anthraquinone derivatives extraction could achieve the best *** the antibacterial tests showed the raw extraction products had the MIC(minimal inhibitory concentration)of 20μg=mL and 30μg=mL to Staphylococcus aureus and Escherichia coli,respectively.

关键词： Anthraquinone derivatives photometry optimum extraction conditions Rheum officinale Baill antibacterial

Simultaneously achieving high energy density and responsivity in submicron BaTiO_(3) film capacitors integrated on Si

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第2期13卷 198-206页

作者： Jun Ouyang Yinxiu Xue Chuanqi Song Meiling yuan Kun Wang Yuyao Zhao Hongbo cheng Hanfei Zhu chao Liu Institute of Advanced Energy Materials and Chemistry School of Chemistry and Chemical EngineeringQilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Key Laboratory of Key Film Materials&Application for Equipment School of Material Sciences and EngineeringXiangtan UniversityXiangtan 411105China School of Materials Science and Engineering Shandong UniversityJinan 250061China Academic Affairs Office Civil Aviation University of ChinaTianjin 300300China China Tobacco Shandong Industrial Co. Ltd.Jinan 250014China

In the research field of energy storage dielectrics,the“responsivity”parameter,defined as the recyclable/recoverable energy density per unit electric field,has become critically important for a comprehensive evaluation of the energy storage capability of a *** this work,high recyclable energy density and responsivity,i.e.,W_(rec)=161.1 J·cm^(-3) and ξ=373.8 J·(kV·m^(2))^(-1),have been simultaneously achieved in a prototype perovskite dielectric,BaTiO_(3),which is integrated on Si at 500℃ in the form of a submicron thick *** ferroelectric film features a multi-scale polar structure consisting of ferroelectric grains with different orientations and inner-grain ferroelastic domains.A LaNiO_(3) buffer layer is used to induce a{001}textured,columnar nanograin microstructure,while an elevated deposition temperature promotes lateral growth of the nanograins(in-plane diameter increases from~10-20 nm at lower temperatures to~30 nm).These preferably oriented and periodically regulated nanograins have resulted in a small remnant polarization and a delayed polarization saturation in the film’s P-E behavior,leading to a high recyclable energy ***,an improved polarizability/dielectric constant of the BaTiO_(3) film has produced a much larger maximum polarization than those deposited at lower temperatures at the same electric field,leading to a record-breaking responsivity for this simple perovskite.

关键词： energy storage energy density responsivity BaTiO_(3) dielectric capacitor Si

Oxygen reduction electrocatalysis:From conventional to single-atomic platinum-based catalysts for proton exchange membrane fuel cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2024年第2期18卷 206-222页

作者： cheng yuan Shiming ZHANG Jiujun ZHANG Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghai 200444China

Platinum(Pt)-based materials are still the most efficient and practical catalysts to drive the sluggish kinetics of cathodic oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).However,their catalysis and stability performance still need to be further improved in terms of corrosion of both carbon support and Pt catalyst particles as well as Pt loading *** on the developed synthetic strategies of alloying/nanostructuring Pt particles and modifying/innovating supports in developing conventional Pt-based catalysts,Pt single-atom catalysts(Pt SACs)as the recently burgeoning hot materials with a potential to achieve the maximum utilization of Pt are comprehensively reviewed in this *** design thoughts and synthesis of various isolated,alloyed,and nanoparticlecontained Pt SACs are *** single-atomic Pt coordinating with non-metals and alloying with metals as well as the metal-support interactions of Pt single-atoms with carbon/non-carbon supports are emphasized in terms of the ORR activity and stability of the *** advance further research and development of Pt SACs for viable implementation in PEMFCs,various technical challenges and several potential research directions are outlined.

关键词： oxygen reduction electrocatalysis Pt singleatom catalysts conventional Pt-based catalysts design thoughts and synthesis metal-support interactions

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

在线全文

维普期刊数据库

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

Structural and elastic properties of Ce2O3 under pressure from LDA＋U method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2013年第4期8卷 405-411页

作者： yuan-yuan Qi Zhen-Wei Niu Cal cheng Yan cheng Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China

We investigate the structural and elastic properties of hexagonal Ce2O3 under pressure using LDA＋U scheme in the frame of density functional theory （DFT）. The obtained lattice constants and bulk modulus agree well with the available experimental and other theoretical data. The pressure dependences of normalized lattice parameters a/ao and c/co, ratio c/a, and normalized primitive volume V/Vo of Ce2O3 are obtained. Moreover, the pressure dependences of elastic properties and three anisotropies of elastic waves of Ce2O3 are investigated for the first time. We find that the negative value of Ca4 is indicative of the structural instability of the hexagonal structure Ce2O3 at zero temperature and 30 GPa. Finally, the density of states （DOS） of Ce2O3 under pressure is investigated.

关键词： elastic properties high pressure density functional theory Ce2O3

维普期刊数据库

Trends in the Prevalence of Births with Chromosomal Abnormalities—Haidian District,Beijing Municipality,China,2013–2022

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2023年第36期5卷 791-796页

作者： Shuangbo Xia chao Meng Xiao cheng Duoduo Wang Yaxian Wu Zhiwen Li yuan Wei Jufen Liu Department of Epidemiology and Biostatistics School of Public HealthPeking UniversityBeijingChina Institute of Reproductive and Child Health/National Health Commission Key Laboratory of Reproductive Health Peking UniversityBeijingChina Department of Maternal Health Care Beijing Haidian Maternal and Child Health HospitalBeijingChina Department of Gynaecology and Obstetrics Peking University Third HospitalBeijingChina

Summary What is already known about this topic?The primary causes of early miscarriage and stillbirth are chromosomal abnormalities(CAs)whose prevalence has been observed to increase in recent *** is added by this report?According to data received from a hospital-based birthdefect surveillance system in the Haidian District,Beijing,there was a significant increase in the prevalence of CAs along with most subtypes from 2013 to 2022.

关键词： Beijing District birth

Arteriolosclerosis differs from venular collagenosis in relation to cerebrovascular parenchymal damages:an autopsy-based study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2023年第4期8卷 267-275,I0002-I0009页

作者： yuan Cao Mei-Ying Huang Chen-Hui Mao Xue Wang yuan-yuan Xu Xiao-Jing Qian chao Ma Wen-Ying Qiu Yi-cheng Zhu Department of Neurology State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Human Anatomy Histology and EmbryologyInstitute of Basic Medical SciencesNeuroscience CenterChinese Academy of Medical SciencesSchool of Basic MedicinePeking Union Medical CollegeBeijingChina

Background and purpose Cerebrovascular parenchymal damage is prevalent in ageing brains;however,its vascular aetiology has not been fully *** addition to the underlying role of sclerotic arterioles,the correlation between collagenised venules has not been ***,we aimed to investigate the associations between microvascular injuries,including arteriolosclerosis and venular collagenosis,and related parenchymal damages in ageing brains,to investigate the underlying *** We evaluated arteriolosclerosis and venular collagenosis in 7 regions from 27 autopsy cases with no history of stroke or brain *** correlations between the ratio of arteriolosclerosis,venular collagenosis and the severity of cerebrovascular parenchymal damage,including lacunes,microinfarcts,myelin loss,and parenchymal and perivascular haemosiderin deposits,were *** Arteriolosclerosis and venular collagenosis became more evident with *** was associated with lacunes(p=0.004)and brain parenchymal haemosiderin deposits in the superior frontal cortex(p=0.024)but not with leukoaraiosis *** collagenosis was not associated with the number of lacunes or haemosiderin,while white matter generally became paler with severe venular collagenosis in the periventricular(β=−0.430,p=0.028)and deep white matter(β=−0.437,p=0.025).Conclusion Our findings imply an important role for venular lesions in relation to microvessel-related parenchymal damage which is different from that for *** underlying mechanisms of both cerebral arterioles and venules require further investigation.

关键词： sclerosis damage injuries

Tumor targeting of HPMA copolymer conjugates containing sulfadiazine groups

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 Chemical Letters 2012年第7期23卷 875-878页

作者： Jian chao yuan Xiao Li Xie Xian Wu Zeng Hong Yun Guo cheng Ping Miao Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education Key Laboratory of Polymer Materials of Gansu ProvinceCollege of Chemistry&Chemical EngineeringNorthwest Normal UniversityLanzhou 730070China Department of Nuclear Medicine Gansu Academy of Medical Sciences&Gansu Provincial Tumor HospitalLanzhou 730050China

To develop new tumor targeting macromolecular conjugates,poly（HPMA）-SD-APMA-DTPA（HPMA：N-（2-hydroxypropyl）- methacrylamide;APMA：N-（3-ammopropyl）methacrylamide;DTPA：diethylenetriaminepentaacetic acid;SD：sulfadiazine） was synthesized and *** poly（HPMA）-SD-DTPA conjugates were radiolabeled with the radionuclide ^（99m）Tc and tested for uptake by cultured H22 cells in ***-^（99m）Tc（radiotracer 1） and poly（HPMA）-DTPA-^（99m）Tc（radiotracer 2） were also synthesized and characterized for *** uptake of poly（HPMA）-SD-DTPA-^（99m）Tc（radiotracer 3,34.76%） was significantly higher than that of poly（HPMA）-DTPA-^（99m）Tc（16.40%）,indicating that uptake of the poly（HPMA）-SD-DTPA-^（99m）T was active *** uptake of poly（HPMA）-DTPA-^（99m）Tc was significantly higher than that of DTPA-^（99m）Tc（2.98%）, suggesting that uptake of the poly（HPMA）-DTPA-^（99m）T was passive *** data suggest that the poly（HPMA）-SDAPMA -DTPA conjugates might be useful as tumor targeting macromolecular conjugates.

关键词： Tumor targeting HepatoceUular carcinoma HPMA copolymer conjugates Radiotracer

维普期刊数据库