检索结果-南通市图书馆

Warming intensified the effects of nitrogen addition on N_(2)O emissions from alpine meadow in the northern qinghai-Tibet Plateau

引用

Advances in Climate Change Research 2024年第1期15卷 101-112页

作者： Ming-Jie LI Yi-qing GE Hasbagan GANJURJAV guo-Zheng HU Hong-Bao WU Jun YAN Shi-Cheng HE qing-Zhu GAO Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China National Agricultural Experimental Station for Agricultural Environment Nagqu 852100China Ecology and Nature Conservation Institute Chinese Academy of ForestryBeijing 100091China College of Resource and Environment Anhui Science and Technology UniversityFengyang 233100China Nagqu Agriculture Animal Husbandryand Prataculture Science and Technology Research and Extension CenterNagqu 852100China Tongliao Experimental Middle School Tongliao 028000China

Warming and nitrogen(N)addition may impact soil nitrous oxide(N_(2)O)emissions,but the relationship between plant community composition and soil microbial activities remains *** a two-year field study in the qinghai-Tibet Plateau,open-top chambers were used to quantify the effects of warming,N-addition,and their interactions on N_(2)O *** found that the N-addition greatly increased N_(2)O emissions by 77.4%in 2018 when compared to the control *** contrast,warming showed little effect on N_(2)0 emissions but did increase the activity of enzymes associated with soil nitrification and denitrification.A combined effect of warming and N-addition of resulted in 208.6%(2018)and 90.8%(2019)increase in N_(2)0 emissions,respectively,compared to the individual treatments of warming or *** warming in alpine meadows is causally linked to increased legume biomass which is further intensified with the *** legume biomass(p<0.05),soil moisture(p<0.001)and enzyme activity(p<0.001)had a positive effect on N_(2)0 emissions,while diminished microbial carbon/nitrogen(MBC/MBN)(p<0.05)correlated with reduced N_(2)O *** results indicated that N-addition has a positive effect on N_(2)O emissions,and the addition of warming further intensifies this *** increased dominance of legumes and microbial N content contributes to this *** outcomes suggest that warming and atmospheric N deposition can stimulate N_(2)O emissions of alpine meadows inthefuture.

关键词： Alpine meadow Community composition Nitrogen addition Nitrous oxide flux qinghai-Tibet Plateau Warming

来源：

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

Multi-physical fields distribution in billet during helical electromagnetic stirring:A numerical simulation research

引用

China Foundry 2024年第1期21卷 51-59页

作者： Dong Pan qing-tao guo Kai-lun Zhang Fu-zhi Yu Yu-ying Li Yu-bao Xiao State Key Laboratory of Metal materials for marine Equipment and Application Anshan 114009LiaoningChina Ansteel Beijing Research Institute Co. Ltd.Beijing 102200China

Electromagnetic stirring is one of the widely applied techniques to modify the quality of casting *** from conventional rotate stirring,the helical stirring is more professional in assisting multi-dimensional flow of molten metal and eliminating solidification *** this study,the single-winding helical stirring(SWHS)was introduced,offering advantages such as smaller volume and lower electromagnetic shielding compared to traditional helical stirring *** a comprehensive numerical simulation,the stirring parameters of SWHS were adjusted to yoke inclination angle of 43°and frequency of 12 *** higher electromagnetic force and flow velocity in drawing direction,as well as the lower temperature gradient induced by the SWHS,are positive factors for homogeneous solidification of *** experimental results on Al-8%Si alloy and 0.4%C-1.1%Mn steel demonstrate that compared to rotate stirring,the SWHS process can induce better billet quality and is more effective in accelerating the equiaxed expansion and reducing element *** SWHS process can enhance the equiaxed ratio of the billet by 58.3%and reduce segregation degree of carbon element by 10.97%.Consequently,SWHS holds great promise as a potential approach for improving the quality of continuous casting billets.

关键词： billet electromagnetic stirring helical solidification element segregation numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling of LF refining process:a review

引用

Journal of Iron and Steel Research International 2024年第2期31卷 289-317页

作者： Zi-cheng Xin Jiang-shan Zhang Kai-xiang Peng Jun-guo Zhang Chun-hui Zhang qing Liu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing100083China Tangshan Branch Hebei Iron and Steel Co.Ltd.Tangshan063000HebeiChina Xinjiang Bayi Iron and Steel Co. Ltd.Baosteel GroupWulumuqi830022XinjiangChina

With the increasing demand for energy conservation and emission reduction,more attentions have been paid to the intelligentization,greenization and low carbonization during the transformation and upgrading of steelmaking *** furnace(LF)refining is one of the key procedures in steelmaking process and has been widely used in steelmaking plants for its high equipment matching degree,low equipment investment and outstanding refining *** to the main tasks of LF refining process,the modeling methods of temperature prediction model,slag-making model,alloying model,argon blowing model and model of inclusions behavior were systematically reviewed,and the advantages and disadvantages of each modeling method were *** addition,the technical framework for the future has also been proposed based on existing works,including classification of raw materials,graphic representation of knowledge,introduction,upgradation and management of device/equipment,customization of steelmaking,modeling of refining process,synergy of models,intelligentization of decision-making,automation of control,and digitization of processes and operations,aiming to provide a reference for the modeling and intelligent development of LF refining process.

关键词： LF refining Temperature prediction Slag-making Alloying Argon blowing Inclusion behavior Modeling method

来源：

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

Review of bio-inspired image sensors for efficient machine vision

引用

Advanced Photonics 2024年第2期6卷 7-19页

作者： Wenhao Tang qing Yang Hang Xu Yiyu guo Jiqiang Zhang Chunfang Ouyang Leixin Meng Xu Liu Zhejiang Laboratory Research Center for Frontier Fundamental StudiesHangzhouChina Zhejiang University College of Optical Science and EngineeringState Key Laboratory of Extreme Photonics and InstrumentationHangzhouChina ZJU-Hangzhou Global Scientific and Technological Innovation Center HangzhouChina Shanghai Jiao Tong University Chip Hub for Integrated Photonics Xplore(CHIPX)WuxiChina

With the rapid development of sensor networks,machine vision faces the problem of storing and computing massive *** human visual system has a very efficient information sense and computation ability,which has enlightening significance for solving the above problems in machine *** review aims to comprehensively summarize the latest advances in bio-inspired image sensors that can be used to improve machine-vision processing *** briefly introducing the research background,the relevant mechanisms of visual information processing in human visual systems are briefly discussed,including layerby-layer processing,sparse coding,and neural ***,the cases and performance of image sensors corresponding to various bio-inspired mechanisms are ***,the challenges and perspectives of implementing bio-inspired image sensors for efficient machine vision are discussed.

关键词： bio-inspired image sensor machine vision layer-by-layer processing sparse coding neural adaptation

来源：

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

Design parameter optimization method for a prestressed steel structure driven by multi-factor coupling

引用

Frontiers of Structural and Civil Engineering 2024年第7期18卷 1066-1083页

作者： guo-Liang SHI Zhan-Sheng LIU De-Chun LU qing-Wen ZHANG majid DEZHKAM Ze-Qiang WANG Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China The Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education Beijing University of TechnologyBeijing 100124China Beijing Building Construction Research Institute Co. Ltd.Beijing 100039China

To achieve efficient structural design,it is crucial to reduce the cost of materials while ensuring structural *** study proposes an optimization method for design parameters(DPs)in a prestressed steel structure driven by multi-factor *** accomplish this,a numerical proxy model of prestressed steel structures is established with integration of DPs and mechanical parameters(MPs).A data association-parameter analysis-optimization selection system is established.A correlation between DPs and MPs is established using a back propagation(BP)neural *** correlation provides samples for parameter analysis and optimization *** are used to characterize the safety of the *** on the safety grade analysis,the key DPs that affect the mechanical properties of the structure are obtained.A mapping function is created to match the MPs and the key *** optimal structural DPs are obtained by setting structural materials as the optimization objective and safety energy as the constraint *** theoretical model is applied to an 80-m-span gymnasium and verified with a scale test physical *** MPs obtained using the proposed method are in good agreement with the experimental *** with the traditional design method,the design cycle can be shortened by more than 90%.Driven by the optimal selection method,a saving of more than 20% can be achieved through reduction of structural material ***,the cross-sectional dimensions of radial cables have a substantial influence on vertical *** initial tension and cross-sectional size of the upper radial cable exhibit the most pronounced impact on the stress distribution in that *** initial tension and cross-sectional size of the lower radial cable hold the greatest sway over the stress distribution in that cable.

关键词： structure design association relationship performance analysis optimum selection experimental verification

来源：

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

Tribological properties of PTFE-based fabric composites at cryogenic temperature

引用

Friction 2024年第2期12卷 245-257页

作者： Mingkun XU Zidan WANG Lihe guo Liming TAO Tianbao ma Tingmei WANG Qihua WANG Key Laboratory of Science and Technology on Wear and Protection of materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Fabric composites are widely employed in self-lubricating bearing liners as solid lubrication *** the tribological behaviors of fabric composites have been extensively studied,the cryogenic tribological properties and mechanisms have been scarcely reported and are largely unclear to instruct material design for aerospace and other high-tech ***,the tribological properties of polytetrafluoroethylene(PTFE)-based hybrid-fabric composites were investigated at cryogenic and ambient temperatures in the form of pin-on-disk friction under heavy *** results suggest that the friction coefficients of the hybrid-fabric composites obviously increase with a decrease in wear when the temperature drops from 25 to−150°***,thermoplastic polyetherimide(PEI),as an adhesive for fabric composites,has better cryogenic lubrication performance than thermosetting phenol formaldehyde(PF)resin,which can be attributed to the flexible chemical structure of *** excellent lubrication performance of hybrid-fabric composites is attributed to the transfer film formed by PTFE fibers on the surface of fabrics.

关键词： cryogenic temperatures fabric composites friction and wear transfer film

来源：

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

Alcohol solvent effect on the self-assembly behaviors of lignin oligomers

引用

Green Energy & Environment 2024年第4期9卷 597-603页

作者： Ya ma Zhicheng Jiang Yafei Luo Xingjie guo Xudong Liu Yiping Luo Bi Shi College of Biomass Science and Engineering Sichuan UniversityChengdu610065China National Engineering Research Center of Clean Technology in Leather Industry Sichuan UniversityChengdu610065China College of Pharmacy(International Academy of Targeted Therapeutics and Innovation) Chongqing University of Arts and SciencesChongqing402160China State Key Laboratory of Utilization of Woody Oil Resource Hunan Academy of ForestryChangsha410004China CAS Key Laboratory of Environmental and Applied Microbiology Environmental Microbiology Key Laboratory of Sichuan ProvinceChengdu Institute of BiologyChinese Academy of SciencesChengdu610041China

The interactions between lignin oligomers and solvents determine the behaviors of lignin oligomers self-assembling into uniform lignin nanoparticles(LNPs).Herein,several alcohol solvents,which readily interact with the lignin oligomers,were adopted to study their effects during solvent shifting process for LNPs’*** lignin oligomers with widely distributed molecular weight and abundant guaiacyl units were extracted from wood waste(mainly consists of pine wood),exerting outstanding self-assembly *** and spherical LNPs were generated in H_(2)O-n-propanol cosolvent,whereas irregular LNPs were obtained in H_(2)O-methanol *** unsatisfactory self-assembly performance of the lignin oligomers in H_(2)O-methanol cosolvent could be attributed to two *** one hand,for the initial dissolution state,the distinguishing Hansen solubility parameter and polarity between methanol solvent and lignin oligomers resulted in the poor dispersion of the lignin *** the other hand,strong hydrogen bonds between methanol solvent and lignin oligomers during solvent shifting process,hindered the interactions among the lignin oligomers for self-assembly.

关键词： Lignin oligomers Alcohol solvent Self-assembly LNPs Solvent effects

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ammonia storage and slip under steady and transient state in close-coupled SCR

引用

Journal of Environmental Sciences 2024年第4期138卷 470-481页

作者： Shiyu Liu Zhaohuan Zhang Zexian guo Boyuan Wang Buyu Wang Xiao ma Shijin Shuai State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China Institute for Aero Engine Tsinghua UniversityBeijing 100084China

The close-coupled selective catalytic reduction(cc-SCR)catalyst is an effective technology to reduce tailpipe NOx emission during cold *** paper investigated the optimal ammonia storage under steady and transient state in the *** study showed that a trade-off between NOx conversion efficiency and ammonia slip is observed on the pareto solutions under steady state,and the optimal ammonia storage is calculated with ammonia slip less than 10μL/L based on the ChinaⅥemission *** rapid temperature increase will lead to severe ammonia slip in the transient test cycle.A simplified 0-D calculation method on ammonia slip under transient state is proposed based on kinetic model of ammonia adsorption and *** addition,the effect of ammonia storage,catalyst temperature and temperature increasing rate on ammonia slip are *** optimal ammonia storage is calculated with maximum ammonia slip less than 100μL/L according to the oxidation efficiency of ammonia slip catalyst(ASC)downstream *** was found that the optimal ammonia storage under transient state is much lower than that under steady state in cc-SCR at lower temperature,and a phase diagram is established to analyze the influence of temperature and temperature increasing rate on optimal ammonia storage.

关键词： Close-coupled SCR Ammonia storage and slip Steady and transient state Generic algorithm

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comparison of nonlinear modeling methods for the composite rubber clamp

引用

Applied mathematics and Mechanics(English Edition) 2024年第5期45卷 763-778页

作者： Yiming CAO Hui ma Xumin guo Bingfeng ZHAO Hui LI Xin WANG Bing WANG School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion Systems of Ministry of Education of China Northeastern UniversityShenyang 110819China AVIC Shenyang Engine Design Institute Shenyang 110013China Dalian Mengyu machinery Co. Ltd.Dalian 116317Liaoning ProvinceChina

The cubic stiffness force model(CSFM)and Bouc-Wen model(BWM)are introduced and compared *** unknown coefficients of the nonlinear models are identified by the genetic algorithm combined with *** fitting the identified nonlinear coefficients under different excitation amplitudes,the nonlinear vibration responses of the system are *** results show that the accuracy of the BWM is higher than that of the CSFM,especially in the non-resonant ***,the optimization time of the BWM is longer than that of the CSFM.

关键词： pipeline system nonlinear clamp model composite rubber clamp amplitude-dependent characteristic vibration response experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamically updated digital twin for prognostics and health management:Application in permanent magnet synchronous motor

引用

Chinese Journal of Aeronautics 2024年第6期37卷 244-261页

作者： Haoyu guo Shaoping WANG Jian SHI Tengfei ma Giorgio GUGLIERI Rujun JIA Fausto LIZZIO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 310023China Department of Mechanical and Aerospace Engineering Polytechnic University of TurinTurin 10129Italy Beihang Ningbo Research Institute Ningbo 315800China

Current research on Digital Twin(DT)based Prognostics and Health management(PHM)focuses on establishment of DT through integration of real-time data from various sources to facilitate comprehensive product monitoring and health ***,there still exist gaps in the seamless integration of DT and PHM,as well as in the development of DT multi-field coupling modeling and its dynamic update *** the product experiences long-period degradation under load spectrum,it is challenging to describe the dynamic evolution of the health status and degradation progression *** addition,DT update algorithms are difficult to be integrated simultaneously by current *** paper proposes an innovative dual loop DT based PHM framework,in which the first loop establishes the basic dynamic DT with multi-filed coupling,and the second loop implements the PHM and the abnormal detection to provide the interaction between the dual loops through updating *** proposed method pays attention to the internal state changes with degradation and interactive mapping with dynamic parameter ***,the Independence Principle for the abnormal detection is proposed to refine the theory of *** at the first loop focus on accurate modeling of multi-field coupling,while the events at the second loop focus on real-time occurrence of anomalies and the product degradation *** interaction and collaboration between different loop models are also ***,the Permanent magnet Synchronous Motor(PMSM)is used to verify the proposed *** results show that the modeling method proposed can accurately track the lifecycle performance changes of the entity and carry out remaining life prediction and health management effectively.

关键词： Digital Twin(DT) Dynamic Update Independence Principle Multi-field Coupling Permanent magnet Synchronous Motor(PMSM) Prognostics and Health management(PHM)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：