检索结果-南通市图书馆

Land Use Regionalization of Rural Settlements in China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2013年第4期23卷 421-434页

作者： song wei chen Baiming ZHANG ying Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences

This paper compartmentalizes regional land use of rural settlements in China by employing a hierarchical clustering *** statistic data are sourced from the National Bureau of Statistics of China(NBSC) and the data of land use change from the Ministry of Land and Resources of China(MLRC).The population of rural settlement decreases from the southeast to the northwest of China and the density of rural settlement decreases from the east to the west of ***-use scale of rural settlement,the proportion of one-storey houses and the average household area decrease from the north to the south of *** ratio of area of cultivated land to rural settlement is high in the northeast and southwest of China but low in the southeast of *** land use regionalization of rural settlement can be divided into four regions,namely:the northern region of China,qinghai-Tibet,Yunnan-Guizhou,and the middle and eastern region of *** northern region of China and the middle and eastern region of China can be further divided into nine sub-regions:Xinjiang,Northeast China,Ningxia and Inner Mongolia,North China,the south of the Changjiang(Yantze) River and Sichuan Basin,Jiangsu-Shanghai,South China,the Loess Plateau,and *** consideration of the significant regional differences,it is proposed that different policies should be implemented regarding the utilization and management of rural settlements.

关键词： rural settlement land use regionalization hierarchical analysis China

Enhanced copper recovery from low grade copper sulfide ores through bioleaching using residues produced by fermentation of agricultural wastes

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2022年第12期29卷 2136-2143页

作者： wei chen Shenghua Yin qing song Leiming Wang Xun chen Key Laboratory of Ministry of Education for High-Efficient Mining and Safety of Metal University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

Effects of residues produced by agricultural wastes fermentation(AWF)on low grade copper sulfide ores bioleaching,copper recovery,and microbial community were *** results indicated that adding appropriate bulk of AWF made contributions to low grade copper sulfide ores bioleaching,which may be mainly realized through reducing the passivation layer formed by Fe3+*** copper recovery(78.35%)and bacteria concentration(9.56×10^(7)cells·mL^(−1))were yielded in the presence of 5 g·L^(−1)*** result of 16S rDNA analysis demonstrated that microbial community was differentiated by adding *** proportion,such as Acidithiobacillus ferrooxidans,Moraxella osloensis,and Lactobacillus acetotolerans changed *** difference between samples was showed according to beta diversity index,and the maximum value reached *** ferrooxidans accounted for the highest proportion throughout the bioleaching process,and that of sample in the presence of 5 g·L^(−) AWF reached 28.63%.The results should show reference to application of agricultural wastes and low grade copper sulfide ores.

关键词： low grade copper sulfide ores bioleaching agricultural wastes fermentation microbial community

Modular assembly of Co4-thiacalix[4]arene units and Keggin-type SiW12O40 for visible-light photothermal conversion

在线全文

学校读者我要写书评

暂无评论

Tungsten 2025年第1期7卷 112-119页

作者： Jia-Hui Li qing Zhao Dong-Ao Mao Kun Zhou Bao-Kuan chen Yan-Feng Bi School of Petrochemical Engineering Liaoning Petrochemical University

The construction of metal-organic coordination clusters（MCCs） using modular secondary building units is an important method for preparing functional *** this study,two new MCCs modularly assembled from Keggin-type {SiW12O40}H4TC4A=p-tert-Butylthiacalix[4]arene(SiW12) units and thiacalixarene-supported Co4-thiacalix[4]arene(Co4-TC4A polynuclear second-building units（PSBUs,H4TC4A=p-tert-Butylthiacalix[4]arene） are *** two MCCs,abbreviated as Co4-SiW12and Co8-SiW12,were structurally characterized by single-crystal X-ray *** Co4-SiW12is a supramolecular structure involving cation-anion interactions between Co4-TC4A PSBUs and ***8-SiW12features "barbell-like" shapes with two Co4-TC4A coordinatively linked to a Keggin-type SiW12unit on opposite via W-O_t-Co *** coordination of Co4-TC4A to SiW12in Co8-SiW12resulted in significantly improved photothermal conversion performances compared with Co4-SiW12and pure SiW12or ***-gap determination and photophysical analysis combined with density functional theory calculations indicated the binding mode between Co4-TC4A PSBUs and SiW12,which considerably influences the way of electron transport and the conversion ability of visible light to heat.

关键词： Modular construction Photothermal conversion Polyoxometalate Thiacalixarene

生物可降解聚乳酸共衣康酸丁二醇酯/纳米二氧化硅包装材料对发酵酸奶贮藏品质及活菌数的影响

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

食品与发酵工业 2025年第1期51卷 108-115页

作者：蒋伟陈钟生张元董同力嘎内蒙古农业大学食品科学与工程学院内蒙古呼和浩特010018

探讨不同阻隔性的聚乳酸共衣康酸丁二醇酯/纳米二氧化硅共聚物薄膜[poly(L-lactic-co-butanediol itaconate)nano-silica copolymer films,PLBI-SiO_(2)]包装对发酵酸奶贮藏效果,并对贮藏期间酸奶的理化指标和活菌数进行测定。结果表明:... 详细信息

探讨不同阻隔性的聚乳酸共衣康酸丁二醇酯/纳米二氧化硅共聚物薄膜[poly(L-lactic-co-butanediol itaconate)nano-silica copolymer films,PLBI-SiO_(2)]包装对发酵酸奶贮藏效果,并对贮藏期间酸奶的理化指标和活菌数进行测定。结果表明:在4℃贮藏0~21 d期间,所有包装组的pH都呈现下降趋势,PLBI-SiO_(2)0.5%包装组与对照(市售)组在贮藏后期pH下降得到减缓;在贮藏期间,PLBI-SiO_(2)0.5%包装组与对照(市售)组能有效维持酸奶的质构特性与持水能力,同时也保持良好的感官评价与表观黏度;所有包装组的活菌数在整个贮藏期间都呈现逐渐降低的趋势,但随包装阻隔性的提高,下降幅度得到减缓,PLBI-SiO_(2)0.5%包装组与对照组在贮藏21 d时,保加利亚乳杆菌与嗜热链球菌都保持在10~7 CFU/mL以上。综合各项指标,PLBI-SiO_(2)0.5%包装组在贮藏21 d可以维持酸奶贮藏品质并几近于市售包装组,这为酸奶及其他发酵乳替代包装材料提供了一定的理论基础。

关键词：酸奶贮藏纳米二氧化硅聚乳酸共衣康酸丁二醇酯纳米二氧化硅共聚物阻隔性

The Security of Using Large Language Models:A Survey With Emphasis on ChatGPT

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2025年第1期 1-26页

作者： wei Zhou Xiaogang Zhu qing-Long Han Lin Li Xiao chen Sheng Wen Yang Xiang the School of Science Computing and Engineering Technologies Swinburne University of Technology IEEE the School of Computer and Mathematical Sciences the University of Adelaide Adelaide the Faculty of Science and Engineering Southern Cross University the School of Information and Physical Sciences the University of Newcastle

ChatGPT is a powerful artificial intelligence(AI)language model that has demonstrated significant improvements in various natural language processing(NLP) tasks. However, like any technology, it presents potential security risks that need to be carefully evaluated and addressed. In this survey, we provide an overview of the current state of research on security of using ChatGPT, with aspects of bias, disinformation, ethics, misuse,attacks and privacy. We review and discuss the literature on these topics and highlight open research questions and future *** this survey, we aim to contribute to the academic discourse on AI security, enriching the understanding of potential risks and mitigations. We anticipate that this survey will be valuable for various stakeholders involved in AI development and usage, including AI researchers, developers, policy makers, and end-users.

关键词：

Trinuclear gold-catalyzed site-selective alkylation of peptides

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 249-256页

作者： qing-Yun Fang chengyihan Gu yinghan chen Wencheng Yan Yong Liang weipeng Li chengjian Zhu Jie Han Jin Xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic Materials Chemistry and Biomedicine Innovation Center (Chem BIC) School of Chemistry and Chemical Engineering Nanjing University Green Catalysis Center College of Chemistry Zhengzhou University State Key Laboratory of Natural Medicines China Pharmaceutical University

Selective modification of peptides has always been a challenging issue. The selective alkylation of peptides can alter the biological activity and physical properties of molecules, and it has gained significant research interest. We herein disclose an intriguing gold-catalyzed alkylation of peptides using bench-stable unactivated alkyl bromides under photoredox catalysis. A wide range of structurally diverse primary, secondary and tertiary alkyl bromides serve as effective coupling partners to precisely connect with the α-C(sp3)–H in glycine residue of peptides. This protocol demonstrates an exceptionally broad scope for alkyl halides and excellent tolerance for a wide range of useful functional groups. A series of relay transformations to construct cyclic peptides, to proceed click reaction and to realize peptide fluorescence labeling further enhance its synthetic practicality. In addition, mechanistic studies and density functional theory(DFT) calculations reveal an inner-sphere and subsequent outersphere single electron transfer(SET) mechanism.

关键词： gold catalysis peptide alkylation C-C coupling radical

同方期刊数据库

Homogeneity analysis of Y-bearing 12Cr ferritic/martensitic steel fabricated by vacuum induction melting and casting

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2020年第8期27卷 940-951页

作者： wei-wei Guo Xiao-xin Zhang ying-xue chen Zhi-yuan Hong qing-zhi Yan Institute of Nuclear Materials School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China Advanced Energy Research Center Shenzhen UniversityShenzhen 518060GuangdongChina Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Optoelectronic EngineeringShenzhen UniversityShenzhen 518060GuangdongChina

Advanced oxide metallurgy technique was adopted to produce 100-kg Y-bearing 12Cr ferritic/martensitic steel via vacuum induction melting and casting route. Subsequently, nine specimens at top, middle and bottom regions of the sheet were char-acterized to evaluate the homogeneity of chemical composition, microstructure and mechanical properties. The small vibra-tion of hardness (200–220 HBW), ultimate tensile strength (672–678 MPa), yield strength (468–480 MPa), total elongation (26.2%–30.5%) and Charpy energy at room temperature (98–133 J) and at ??40 ℃ (12–40 J) demonstrated that mechanical properties’ homogeneity of Y-bearing steel was acceptable although slight Y segregation and inhomogeneous microstructure occurred at the bottom. Furthermore, the effect of Y content on microstructure characteristics and mechanical properties was explained and the comparison of failure mechanism for the dual-phase steel between tensile test (i.e., quasi-static loading) and Charpy test (i.e., dynamic loading) was discussed in detail.

关键词： Y-bearing ferritic/martensitic steel Casting Homogeneity Chemical composition Microstructure characteristics Mechanical property

Hollow-fiber gas penetration electrodes efficiently produce renewable synthetic fuels

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

Frontiers in Energy 2022年第5期16卷 700-705页

作者： Yanfang song Xiao DONG wei chen wei wei Low-Carbon Conversion Science and Engineering Center Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China

Increasing CO_(2) levels in the atmosphere due to the consumption of large amounts of fossil fuels is exacerbating global climate change,which seriously threatens sustainable human *** a responsible and respectable country,China has announced remarkable goals of reaching a carbon emission peak and achieving carbon neutrality,which are challenging missions with enormous contributions to the *** a strategic support,disruptive and transformative energy technologies are urgently required to develop new green and low-carbon energy *** energy sources such as wind and sun,which can generate zero-carbon electric power,have been rapidly developed in recent years.

关键词： fuels fiber seriously

A Review on Cable-driven Parallel Robots

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2018年第4期31卷 37-47页

作者： Sen Qian Bin Zi wei-wei Shang qing-song Xu School of Mechanical Engineering Hefei University of Technology Department of Automation University of Science and Technology of China Department of Electromechanical Engineering Faculty of Science and TechnologyUniversity of Macao

Cable-driven parallel robots(CDPRs) are categorized as a type of parallel manipulators. In CDPRs, flexible cables are used to take the place of rigid links. The particular property of cables provides CDPRs several advantages, including larger workspaces, higher payload-to-weight ratio and lower manufacturing costs rather than rigid-link robots. In this paper, the history of the development of CDPRs is introduced and several successful latest application cases of CDPRs are presented. The theory development of CDPRs is introduced focusing on design, performance analysis and control theory. Research on CDPRs gains wide attention and is highly motivated by the modern engineering demand for large load capacity and workspace. A number of exciting advances in CDPRs are summarized in this paper since it is proposed in the 1980 s, which points to a fruitful future both in theory and application. In order to meet the increasing requirements of robot in different areas, future steps foresee more in-depth research and extension applications of CDPRs including intelligent control, composite materials, integrated and reconfigurable design.

关键词： Cable-driven parallel robots Design and modelling Control and planning Performance and optimization