检索结果-南通市图书馆

SOME TRACE METAL IONS IN NATURAL WATERS OF TIANSHAN MOUNTAINS AND QINGHAI-TIBET PLATEAU- AN EVIDENCE OF THE HOMOGENEOUS DISTRIBUTION OF TRACE METAL IONS IN NATURAL WATERS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and limnology 1984年第1期2卷 81-87页

作者： gu hongkan, liu mingxing, li guoji, bao wanyou and zhang shoulin(Institute of Oceanology, Academia Sinica, Qingdao) 1. Institute of Oceanology Academia Sinica Qingdao

The concentrations of Zn, Cd, Pb, Cu ions are shown to be similar in natural waters of Tianshan Mountains and Qinghai-Tibet plateau and to be similar in those of the sea water. The average and variability of concentrations of trace metal ions in fresh water are Zn 5.7±1.5, Cd 0.092±0.038, Pb 0.048±0.011, and Cu 1.1±0.20 ppb. The average concentrations in the East China Sea are Zn 7.3 （5.5 in 1976）, Cd 0.12, Pb 0.036, and Cu 0.94 ppb. It proves that the homogeneous distribution of trace metal ions （free ion and unstable complexes） in natural waters is present in the nature as a rule.

关键词： AN EVIDENCE OF THE HOMOGENEOUS DISTRIBUTION OF TRACE METAL IONS IN NATURAL WATERS SOME TRACE METAL IONS IN NATURAL WATERS OF TIANSHAN MOUNTAINS AND QINGHAI-TIBET PLATEAU

Effect of exogenous flavins on the microbial corrosion by Geobacter sulfurreducens via iron-to-microbe electron transfer

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 Materials Science & Technology 2024年第4期171卷 129-138页

作者： Yuting Jin Jiaqi li mingxing zhang Borui Zheng Dake Xu Tingyue gu Fuhui Wang Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang 110819China Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) Northeastern UniversityShenyang 110819China Department of Chemical and Biomolecular Engineering Institute for Corrosion and Multiphase TechnologyOhio UniversityAthens OH 45701USA

Microbes can cause or accelerate metal corrosion,leading to huge losses in corrosion damages each *** sulfurreducens is a representative electroactive bacterium in many soils,sediments,and wastew-ater *** has been confirmed to directly extract electrons from elemental ***,little is known about the effect of electron shuttles in *** corrosion on stainless *** this study,we report that exogenous flavins promote iron-to-microbe electron transfer,accelerating micro-bial *** caused 1.3 times deeper pits and increased electron uptake(with 2 times increase of i_(corr))from stainless steel when riboflavin was added to the culture ***-deficient mutant data suggest that *** utilizes riboflavin as a bound-cofactor in outer membrane c-type *** finding that,in the presence of microbes,riboflavin can substantially accelerate corrosion highlights the role of flavin redox cycling for enhanced iron-to-microbe electron transfer by *** and provides new insights in microbial corrosion.

关键词： Extracellular electron transfer Microbiological corrosion Geobacter sulfurreducens Outer membrane c-type cytochromes Exogenous flavins

天山及青藏高原天然水中的痕量金属离子——天然水痕量金属离子均匀分布规律的证实

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

海洋与湖沼 1985年第5期 364-370页

作者：顾宏堪刘明星李国基包万友张首临中国科学院海洋研究所中国科学院海洋研究所青岛

痕量Zn,Cd,Pb,Cu离子的浓度在天山和青藏高原天然水中以及在东海海水中都是相似的。在淡水中的平均浓度分别为Zn 5.7,Cd 0.092,Pb 0.048,Cu 1.1 ppb。这证明天然水中痕量金属离子均匀分布规律是客观存在的。

关键词：络离子金属离子悬浮体悬浮物分散体系天然水痕量金属地球化学组分青藏高原青藏现代强烈隆起区均匀分布一致分布天山

Partial aging can counter-intuitively couple with sulfidation to improve the reactive durability of zerovalent iron

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 Environmental Science & Engineering 2024年第2期18卷 1-11页

作者： Yiwei liu Kaili gu Jinhua zhang Jinxiang li Jieshu Qian Jinyou Shen Xiaohong guan Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing 210094China School of Ecological and Environmental Sciences East China Normal UniversityShanghai 200241China

Sulfated zero-valent iron(SZVI)has shown promising applications in wastewater ***,the rapid decline in the reactivity of SZVI with time limits its real *** mediate this problem,partial aging was proposed to improve the reactive durability of *** Cr(VI)as the target contaminant,we found that the aged ZVI(AZVI)gradually lost reactivity as aging time increased from 0.5 to 2 ***-intuitively,the partially aged SZVI(ASZVI)showed greater reactivity than SZVI when exposed to oxygenated water for a period ranging from 0.5 to 14 *** addition,the ASZVI with 0.5 d of aging time(ASZVI-0.5)not only maintained reactivity in successive runs but also increased the Cr(VI)removal capacity from 9.1 mg/g by SZVI to 19.1 mg/g by *** analysis further revealed that the electron transfer from the Fe0 core to the shell was mediated by the conductive FeS and FeS2 in the subshell of ***,the lepidocrocite and magnetite on the surface of ASZVI facilitated Cr(VI)adsorption and subsequent electron transfer for Cr(VI)***,the iron(hydr)oxide shell could retain the conductive FeS and FeS2 in the subshell,allowing ASZVI to reduce Cr(VI)efficiently and *** general,partial aging can enhance the reactive durability of ZVI when coupled with sulfidation and this synergistic effect will be beneficial to the application of SZVI-based technology for wastewater treatment.

关键词： Zerovalent iron Sulfidation Partial aging Interface reconstruction Electron transfer

Manufacturing process of water-soluble salt-based ceramic cores based on vat photopolymerization

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5期13卷 652-665页

作者： Yuzhen zhang Wenyan Duan Yue gu Xingyao Sun Shan li Bingshan liu Gong Wang Key Laboratory of Space Manufacturing Technology(SMT) Technology and Engineering Center for Space UtilizationChinese Academy of SciencesBeijing 100094China University of Chinese Academy of Sciences Beijing 100049China Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing Changchun University of Science and TechnologyChangchun 130022China

Water-soluble salt-based ceramic cores can be recycled and have excellent high-temperature chemical *** this work,vat photopolymerization was successfully applied to water-soluble salt-based ceramic cores for the first *** powder raw materials of the printing suspension were sodium chloride and ***-precision green bodies were manufactured by optimizing suspensions and *** addition,the postprocessing method was optimized according to the microstructure and mechanical *** sintered part had a high bending strength and smooth ***,the dissolution rate and moisture resistance were compared under different dissolution and storage *** to traditional manufacturing methods,vat photopolymerization enables the production of complex structures without molds and reduces production *** technology is suitable for the rapid iteration of complex structural parts and can be applied to precision parts in aerospace,military,and other technical fields with high cost-effectiveness and sustainability.

关键词： vat photopolymerization water-soluble salt-based ceramic cores defect formation control accuracy moisture rate

Seismic risk assessment and damage analysis: Emerging trends and new developments

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 SAFETY SCIENCE AND RESIliENCE 2024年第3期5卷 365-381页

作者： liu, Yi gu, Yin zhang, Hui Tsinghua Univ Inst Publ Safety Res Dept Engn Phys Beijing 100084 Peoples R China Tsinghua Univ Sch Safety Sci Beijing 100084 Peoples R China Beijing Key Lab City Integrated Emergency Response Beijing 100084 Peoples R China

Earthquakes are major catastrophes that cause great life and economic losses to human society and environment. This paper reviews and synthesizes relevant studies, drawing from a systematic examination of 4229 articles from the Web of Science core collection (1982-2023). Employing the CiteSpace visualization and analysis tool, current research and emerging trends in seismic risk assessment are discussed and analyzed. This paper provides a holistic overview of principal contributions, knowledge sources, interdisciplinary characteristics, and principal research topics in this field. Additionally, we propose key technologies that are in urgent need of enhancement, including data availability, quantity and quality of data, interpretability of machine learning models, performance improvement of machine learning methods and application of foundation models, as well as real-time risk assessment techniques. These insights support both theoretical understanding and practical applications of seismic risk assessment and damage analysis.

关键词： Earthquake Vulnerability Seismic risk assessment Seismic damage analysis CiteSpace HISTORICAL MASONRY TOWERS VULNERABIliTY ASSESSMENT FRAGIliTY CURVES TYPICAL BRIDGES RESIliENCE EARTHQUAKE MODEL FRAMEWORK BUILDINGS NETWORK

A Coupled Thermomechanical Crack Propagation Behavior of Brittle Materials by Peridynamic Differential Operator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 339-361页

作者： Tianyi li Xin gu Qing zhang College of Architectural Engineering Jiangsu Open UniversityNanjing210036China Department of Engineering Mechanics Hohai UniversityNanjing211100China

This study proposes a comprehensive,coupled thermomechanical model that replaces local spatial derivatives in classical differential thermomechanical equations with nonlocal integral forms derived from the peridynamic differential operator(PDDO),eliminating the need for calibration *** model employs a multi-rate explicit time integration scheme to handle varying time scales in multi-physics *** simulations conducted on granite and ceramic materials,this model demonstrates its *** successfully simulates thermal damage behavior in granite arising from incompatible mineral expansion and accurately calculates thermal crack propagation in ceramic slabs during *** account for material heterogeneity,the model utilizes the Shuffle algorithm andWeibull distribution,yielding results that align with numerical simulations and experimental *** coupled thermomechanical model shows great promise for analyzing intricate thermomechanical phenomena in brittle materials.

关键词： Peridynamic differential operator thermomechanical coupling heterogeneity numerical simulation

Defect engineered nickel hydroxide nanosheets for advanced pseudocapacitor electrodes

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 2024年第6期17卷 5233-5242页

作者： Yaohang gu Yuxuan zhang Xuanyu Wang Ateer bao Bo Ni Haijun Pan Xiaoyan zhang Xiwei Qi School of Materials Science and Engineering Northeastern UniversityShenyang 110189China College of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210China Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao 066004China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China

While the past years have witnessed great achievement in pseudocapacitors,the inauguration of electrode materials of high-performance still remains a formidable ***,the capacity and rate capability of the electrode depends largely on its electrical conductivity,which ensures fast charge transfer kinetics in both the grain bulk and grain ***,nickel hydroxides with oxygen vacancies are facilely fabricated via a hydrothermal *** active materials exhibit a high specific capacitance of 3250 F·g^(−1)and a high areal of capacitance of 14.98 F·cm^(−2)at 4.6 mA·cm^(−2).The asymmetric supercapacitor device based on our material delivers a high energy density of~71.6 Wh·kg^(−1)and a power density of~17,300 W·kg^(−1)and could retain~95%of their initial capacitance even after 30,000 *** addition,the defect-rich hydroxides demonstrate higher electrical conductivity as well as dielectric constant,which is responsible for the superior pseudocapacitive *** new scientific strategy in terms of taking the advantages of oxygen vacancies might open up new opportunities for qualified pseudocapacitive materials of overall high performances not only for nickel hydroxides but also for other metal hydroxides/oxides.

关键词： pseudocapacitors nickel hydroxides oxygen vacancies electrical conductivity

Gradient honeycomb metastructure with broadband microwave absorption and effective mechanical resistance

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 Materials Science 2024年第4期6卷 456-466页

作者： Dongmeng li Xia Zheng Hao gu Xiaobo Xuan Bing liu Hongquan Feng Fuheng zhang Shanghai Radio Equipment Research Institute

Multifunctional metastructure integrated broadband microwave absorption and effective mechanical resistance has attracted much attention. However, multifunctional performance is limited by the lack of theoretical approaches to integrated design. Herein, a multi-layer impedance gradient honeycomb(MIGH) was designed through theoretical analysis and simulation calculation, and fabricated using 3D printing technique. A theoretical calculation strategy for impedance gradient structure was established based on the electromagnetic parameter equivalent method and the multi-layer finite iterative method. The impedance of MIGH was analyzed by the theoretical calculation strategy to resolve the broadband absorption. Intrinsic loss mechanism of matrix materials and distributions of electric fields, magnetic fields and power loss were analyzed to investigate the absorption mechanism. Experimental results indicated that a 15 mm thick designed metastructure can achieve the absorption more than 88.9% in the frequency range of 2-18 GHz. Moreover, equivalent mechanical parameters of MIGH was calculated by integral method according to the Y-shaped model. Finite Element analysis of stress distributions were carried out to predict the deformation behavior. Mechanical tests demonstrate that MIGH achieved the compression modulus of 22.89 MPa and flexure modulus of 17.05 MPa. The integration of broadband electromagnetic absorption and effective mechanical resistance was achieved by the proposed design principle and fabrication methodology.

关键词： Multifunctional metastructure Broadband microwave absorption Impedance gradient calculation Mechanical characteristics Finite element analysis