检索结果-南通市图书馆

Impact of atmospheric circulations on droughts and drought propagation over China

Science China Earth Sciences 2024年第8期67卷 2633-2648页

作者： Ziye gu Lei gu Jiabo yin Wei fang Lihua XIONG Jun guO Ziyue ZENG Jun XIA School of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Water Resources Engineering and Management Wuhan 430072China Changjiang River Scientific Research Institute Wuhan 430010China

The GRACE satellite mission provides a new approach for monitoring,tracking,and assessing drought conditions by detecting changes in Earth's gravitational fields and inversing signals of terrestrial water storage *** studies of terrestrial water storage anomalies related droughts paid rare attention to the behind atmospheric physical mechanisms,nor quantified the risk propagation patterns between terrestrial water storage deficits and hydrological or agricultural *** this study,we first extract terrestrial water storage(TWS) droughts,hydrological droughts,and agricultural droughts by using multiple variables including TWS from the GRACE/GRACE-FO satellites,runoff and soil moisture from the ERA5-Land reanalysis *** then identify key atmospheric and oceanic oscillation indices affecting water deficits by employing machine learning *** characterize the joint distributions between drought duration and severity by using the Copula function and quantify the risk propagation of hydrological and agricultural droughts to TWS *** results show that:(1) From 2002 to 2021,there is a significant decrasing trend of TWS in China;the WPIO group atmospheric circulation indices(sea surface temperature index within the Western Pacific and Indian Ocean) contributes the most to ***,the sea surface temperature anomalies within the NINO 3.4 region as well as the Western Pacific Warm Pool area index show significantly positive correlation relationships with TWS in southern China;(2) The northwestern China,the Yangtze River basin,and the downstream of the Pearl River basin are the hotspots of TWS ***,the hotspots of hydrological droughts locate in northwestern China and the hotspots of agricultural droughts locate in South China and eastern Tibetan Plateau;(3) The elastic coefficients of hydrological droughts propagating to TWS droughts are higher than those of agricultural droughts,indicating that the TWS droughts

关键词： GRACE satellites Drought Drought propagation Atmospheric circulation Copula function

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

VKFQ:A Verifiable Keyword Frequency Query Framework with Local Differential Privacy in Blockchain

引用

Computers, Materials & Continua 2024年第3期78卷 4205-4223页

作者： Youlin Ji Bo yin Ke gu School of Computer and Communication Engineering Changsha University of Science and TechnologyChangsha410114China

With its untameable and traceable properties,blockchain technology has been widely used in the field of data *** to preserve individual privacy while enabling efficient data queries is one of the primary issues with secure data *** this paper,we study verifiable keyword frequency(KF)queries with local differential privacy in *** the numerical and the keyword attributes are present in data objects;the latter are sensitive and require privacy ***,prior studies in blockchain have the problem of trilemma in privacy protection and are unable to handle KF *** propose an efficient framework that protects data owners’privacy on keyword attributes while enabling quick and verifiable query processing for KF *** framework computes an estimate of a keyword’s frequency and is efficient in query time and verification object(VO)size.A utility-optimized local differential privacy technique is used for privacy *** data owner adds noise locally into data based on local differential privacy so that the attacker cannot infer the owner of the keywords while keeping the difference in the probability distribution of the KF within the privacy *** propose the VB-cm tree as the authenticated data structure(ADS).The VB-cm tree combines the Verkle tree and the Count-Min sketch(CM-sketch)to lower the VO size and query *** VB-cm tree uses the vector commitment to verify the query *** fixed-size CM-sketch,which summarizes the frequency of multiple keywords,is used to estimate the KF via hashing *** conduct an extensive evaluation of the proposed *** experimental results show that compared to theMerkle B+tree,the query time is reduced by 52.38%,and the VO size is reduced by more than one order of magnitude.

关键词： Security data sharing blockchain data query privacy protection

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

Modelling analysis embodies drastic transition among global potential natural vegetations in face of changing climate

引用

Forest Ecosystems 2024年第2期11卷 184-192页

作者： Zhengchao Ren Lei Liu fang yin Xiaoni Liu School of Earth Science and Resources Chang’an UniversityXi’an710054China Research Center of Ecological Construction and Environmental Conservation in Gansu Province Gansu Agricultural UniversityLanzhou730070China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing100101China School of Land Engineering Chang’an UniversityXi’an710054China College of Pratacultural Science Gansu Agricultural UniversityLanzhou730070China

Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention ***,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate *** this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation *** achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV *** find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and ***,we observe an unexpected transition between tundra and savanna despite their geographical *** shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each ***,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing *** spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.

关键词： Potential natural vegetation Global warming Vegetation classification Predicted model CSCS

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

Torque Limit-based Inertial Control Method Based on Delayed Support for Primary Frequency Control of Wind Turbines

引用

Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 561-570页

作者： Wei gu Zaiyu Chen Qun Li Minghui yin Qiang Li Yun Zou School of Automation Nanjing University of Science and TechnologyNanjing 210094China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjing 211103China

To avoid the secondary frequency dip caused by the steep drop of the electrical power of wind turbines(WTs)at the end of frequency support stage,the torque limit-based iner-tial control(TLIC)method sets the power reference as a linear function of rotor speed,rather than the step form for the step-wise inertial ***,the compensation effect on the frequency nadir(FN)caused by the load surge is weakened as the TLIC power is no longer in the step ***,the maximum point of the frequency response component(FRC)contributed by TLIC occurs earlier than the minimum point of FRC corresponding to the load surge,so that the FN cannot be adequately ***,this paper first investigates the relation between the peak and nadir times of FRCs stimulated by the TLIC and load *** this basis,with the compensation principle of matching the peak and nadir times of FRCs,the improved TLIC method based on delayed support is ***,the effectiveness of the proposed method is validated via the experiments on the test bench of wind-integrated power system.

关键词： Wind turbine frequency response component torque limit inertial control delayed support

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

Modulated Degradation Rates of Bone Mineral-Like Calcium Phosphate Glass to Support the Proliferation and Osteogenic Differentiation of Bone Marrow-Derived Stem Cells

引用

Journal of Bionic Engineering 2024年第4期21卷 1960-1974页

作者： Lizhe He Yuye Huang Jiafei gu Xiaoling Liu Jun yin Xiang Gao Department of Neurosurgery The First Affiliated Hospital of Ningbo UniversityNingbo315010China Center for Medical and Engineering Innovation The First Affiliated Hospital of Ningbo UniversityNingbo315010China The State Key Laboratory of Fluid Power Transmission and Control Systems Key Laboratory of 3D Printing Process and Equipment of Zhejiang ProvinceSchool of Mechanical EngineeringZhejiang UniversityHangzhou310028China Faculty of Science and Engineering University of Nottingham Ningbo ChinaNingbo315100China

With an elemental composition similar to bone mineral,and the ability to release phosphorus and calcium that benefit bone regeneration,Calcium Phosphate Glass(CPG)serves as a promising component of bone tissue engineering ***,the degradation of CPG composites typically results in increased acidity,and its impact on bone-forming activity is less *** this work,we prepared 3D-printed composite scaffolds comprising CPG,Poly-ε-caprolactone(PCL),and various Magnesium Oxide(MgO)*** the MgO content effectively suppressed the degradation of CPG,maintaining a physiological pH of the degradation *** the degradation of CPG/PCL scaffolds resulted in upregulated apoptosis of Rat Bone Marrow-derived Stem Cells(rBMSC),scaffolds containing MgO were free from these negative impacts,and an optimal MgO content of 1 wt%led to the most pronounced osteogenic differentiation of *** work demonstrated that the rapid degradation of CPG impaired the renewability of stem cells through the increased acidity of the surrounding media,and MgO effectively modulated the degradation rate of CPG,thus preventing the negative effects of rapid degradation and supporting the proliferation and osteogenic differentiation of the stem cells.

关键词： Phosphate glass Polymer composites 3D printing Bone tissue engineering Scaffolds

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

A"messenger zone hypothesis"based on the visual three-dimensional spatial distribution of motoneurons innervating deep limb muscles

引用

Neural Regeneration Research 2024年第7期19卷 1559-1567页

作者： Chen Huang Shen Wang Jin Deng Xinyi gu Shuhang guo Xiaofeng yin MoE Key Laboratory for Trauma Treatment and Nerve Regeneration Peking UniversityBeijingChina Department of Orthopedics and Trauma Peking University People’s HospitalBeijingChina

Coordinated contraction of skeletal muscles relies on selective connections between the muscles and multiple classes of the spinal motoneuro *** r,current research on the spatial location of the spinal motoneurons innervating differe nt muscles is *** this study,we investigated the spatial distribution and relative position of different motoneurons that control the deep muscles of the mouse hindlimbs,which were innervated by the obturator nerve,femoral nerve,inferior gluteal nerve,deep pe roneal nerve,and tibial *** were visualized by combining a multiplex retrograde tracking technique compatible with three-dimensional imaging of solvent-cleared o rgans(3DISCO)and 3-D imaging technology based on lightsheet fluorescence microscopy(LSFM).Additionally,we propose the hypothesis that"messenger zones"exist as interlaced areas between the motoneuron pools that dominate the synergistic or antagonist muscle *** hypothesize that these interlaced neurons may participate in muscle coordination as messenger *** revealed the precise mutual positional relationships among the many motoneurons that innervate different deep muscles of the *** only do these findings update and supplement our knowledge regarding the overall spatial layout of spinal motoneurons that control mouse limb muscles,but they also provide insights into the mechanisms through which muscle activity is coordinated and the architecture of motor circuits.

关键词： 3-D imaging motoneurons multiple retrograde tracing muscle coordination skeletal muscle spatial distribution optical tissue clearing

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

Ultra reliability and massive connectivity provision in integrated internet of military things(IoMT)based on tactical datalink

引用

Defence Technology（防务技术） 2024年第3期33卷 386-398页

作者： Li Bing Yating gu Lanke Hu Li Bowen Yang Lihua Jue Wang Yue yin Northwestern Polytechnical University Xi'an 710072China China Academy of Information and Communications Technology Beijing 100191China China Intelligent and Connected Vehicles(Beijing)Research Institute Co. LtdBeijing 100176China The 20th Research Institute of China Electronic Technology Group Corporation Xi’an 710068China Xidian University Xi'an 710071China

One of the major challenges arising in internet of military things(IoMT)is accommodating massive connectivity while providing guaranteed quality of service(QoS)in terms of ultra-high *** this regard,this paper presents a class of code-domain nonorthogonal multiple accesses(NOMAs)for uplink ultra reliable networking of massive IoMT based on tactical datalink such as Link-16 and joint tactical information distribution system(JTIDS).In the considered scenario,a satellite equipped with Nr antennas servers K devices including vehicles,drones,ships,sensors,handset radios,*** coded modulation,a special form of multiple input multiple output(MIMO)-NOMA is *** discussion starts with evaluating the output signal to interference-plus-noise(SINR)of receiver filter,leading to the unveiling of a closed-form expression for overloading systems as the number of users is significantly larger than the number of devices admitted such that massive connectivity is *** expression allows for the development of simple yet successful interference suppression based on power allocation and phase shaping techniques that maximizes the sum rate since it is equivalent to fixed-point programming as can be *** proposed design is exemplified by nonlinear modulation schemes such as minimum shift keying(MSK)and Gaussian MSK(GMSK),two pivotal modulation formats in IoMT standards such as Link-16 and *** results show that near capacity performance is ***,the performance is obtained using simple forward error corrections(FECs)of higher coding rate than existing schemes do,while the transmit power is reduced by 6 *** proposed design finds wide applications not only in IoMT but also in deep space communications,where ultra reliability and massive connectivity is a keen concern.

关键词： Satellite network Deep space communications Internet of military things Non-orthogonal multiple access MIMO Link-16 JITDS

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

Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat

引用

The Crop Journal 2024年第4期12卷 1222-1232页

作者： Jingui Wei Zhilong Fan Falong Hu Shoufa Mao fang yin Qiming Wang Qiang Chai Wen yin State Key Laboratory of Arid Land Crop Science Lanzhou 730070GansuChina College of Agronomy Gansu Agricultural UniversityLanzhou 730070GansuChina

Achieving the green development of agriculture requires the reduction of chemical nitrogen(N)fertilizer *** studies have confirmed that returning green manure to the field is an effective measure to improve crop yields while substituting partial chemical N ***,it remains unclear how to further intensify the substituting function of green manure and elucidate its underlying agronomic *** a split-plot field experiment in spring wheat,different green manures returned to the field under reduced chemical N supply was established in an oasis area since 2018,in order to investigate the effect of green manure and reduced N on grain yield,N uptake,N use efficiency(NUE),N nutrition index,soil organic matter,and soil N of wheat in *** results showed that mixed sown common vetch and hairy vetch can substitute 40%of chemical N fertilizer without reducing grain yield or N ***,mixed sown common vetch and hairy vetch under reduced N by 20%showed the highest N agronomy efficiency and recovery efficiency,which were 92.0%and 46.0%higher than fallow after wheat harvest and conventional N application rate,*** increase in NUE of wheat was mainly attributed to mixed sown common vetch and hairy vetch,which increased N transportation quantity and transportation rate at pre-anthesis,enhanced N harvest index,optimized N nutrition index,and increased activities of nitrate reductase and glutamine synthetase of leaf,***,mixed sown common vetch and hairy vetch under reduced N by 20%improved soil organic matter and N ***,mixed sown common vetch and hairy vetch can substitute 40%of chemical N fertilizer while maintaining grain yield and N accumulation,and it combined with reduced chemical N by 20%or 40%improved NUE of wheat via enhancing N supply and uptake.

关键词： Legume green manure Reduced N input Wheat N uptake and supply Agronomic mechanism

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

Machine learning-based performance predictions for steels considering manufacturing process parameters:a review

引用

Journal of Iron and Steel Research International 2024年第7期31卷 1555-1581页

作者： Wei fang Jia-xin Huang Tie-xu Peng Yang Long Fu-xing yin Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin 300132China Institute of New Materials Guangdong Academy of ScienceGuangzhou 510651GuangdongChina

Steels are widely used as structural materials,making them essential for supporting our lives and ***,further improving the comprehensive properties of steel through traditional trial-and-error methods becomes challenging due to the continuous development and numerous processing parameters involved in steel *** address this challenge,the application of machine learning methods becomes crucial in establishing complex relationships between manufacturing processes and steel *** review begins with a general overview of machine learning methods and subsequently introduces various performance predictions in steel *** classification of performance pre-diction was used to assess the current application of machine learning model-assisted *** important issues,such as data source and characteristics,intermediate features,algorithm optimization,key feature analysis,and the role of environmental factors,were summarized and *** insights will be beneficial and enlightening to future research endeavors in this field.

关键词： Steel Manufacturing process Machine learning Performance prediction Algorithm

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

Transformation of long-period stacking ordered structures in Mg-Gd-Y-Zn alloys upon synergistic characterization of first-principles calculation and experiment and its effects on mechanical properties

引用

Journal of Magnesium and Alloys 2024年第5期12卷 1867-1879页

作者： Mingyu Li guangzong Zhang Siqi yin Changfeng Wang ying Fu Chenyang gu Renguo guan School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Key Laboratory of Near-Net Forming of Light Metals of Liaoning Province Dalian Jiaotong UniversityDalian 116028China Engineering Research Center of Continuous Extrusion Ministry of EducationDalian Jiaotong UniversityDalian 116028China Songshan Lake Materials Laboratory Dongguan 523808China

Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are *** transformation process of long-period stacking ordered(LPSO)structure during solidification and heat treatment and its effect on the mechanical properties of experimental alloys are *** reveal that the stacking faults and 18R LPSO phases appear in the as-cast Mg-10Gd-4Y-1Zn-0.6Zr and Mg-10Gd-4Y-2Zn-0.6Zr alloys,*** solution treatment,the stacking faults and 18R LPSO phase transform into 14H LPSO *** Enthalpies of formation and reaction energy of 14H and 18R LPSO are calculated based on *** show that the alloying ability of 18R is stronger than that of *** reaction energies show that the 14H LPSO phase is more stable than the 18R *** elastic properties of the 14H and 18R LPSO phases are also evaluated by first-principles calculations,and the results are in good agreement with the experimental *** precipitation of LPSO phase improves the tensile strength,yield strength and elongation of the *** solution treatment,the Mg-10Gd-4Y-2Zn-0.6Zr alloy has the best mechanical properties,and its ultimate tensile strength and yield strength are 278.7 MPa and 196.4 MPa,*** elongation of Mg-10Gd-4Y-2Zn-0.6Zr reaches 15.1,which is higher than that of Mg-10Gd-4Y0.6Zr *** improving mechanism of elastic modulus by the LPSO phases and the influence on the alloy mechanical properties are also analyzed.

关键词： Mg-Gd-Y-Zn alloys Long-period stacking ordered First-principles calculations Enthalpies Mechanical properties

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：