检索结果-南通市图书馆

Off-farm employment and poverty alleviation in rural China

Journal of Integrative Agriculture 2021年第4期20卷 943-952页

作者： LI Shao-ping dong yong-qing ZHANG Lin-xiu LIU Cheng-fang China Center for Agricultural Policy School of Advanced Agricultural SciencesPeking UniversityBeijing 100871P.R.China College of Management and Economics/Center for Social Science Survey and Data Tianjin UniversityTianjin 300072P.R.China UN Environment Programme-International Ecosystem Management Partnership Beijing 100101P.R.China Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101P.R.China

Two phenomena in the history of China's economic growth during the last four decades are the increase in the share of offfarm employment and the progress in poverty alleviation in rural *** both of them have been well documented in the literature,less is known about the linkage between the *** better understand the role that off-farm employment has played in poverty alleviation in rural China is critically important not only for China but also for those countries that are trying to reduce ***,we examine the impact of off-farm employment on poverty alleviation in rural *** the data from two nationally representative household panel surveys(China National Rural Survey and China Rural Development Survey),this paper provides supporting evidence that off-farm employment contributes to poverty alleviation in rural ***,if household participation in off-farm employment increases by 10 percentage points,the likelihood for a nonpoor household to fall into poverty will decrease by 0.88 percentage point whereas the likelihood for a poor household to climb out of poverty will increase by 3.5 percentage *** a word,off-employment can not only prevent rural residents to fall into poverty but also help those already in poverty climb out of it.

关键词： off-farm employment poverty alleviation rural China

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

Bilateral bidirectional superior cavopulmonary shunt is more beneficial in medium and long term clinical outcomes than unilateral shunt

引用

Chinese Medical Journal 2009年第2期122卷 129-135页

作者： XU Yao-qiang LIU Ying-long LU Xiao-dong LI yong-qing YU Cun-tao Pediatric Cardiac Center Cardiovascular Institute and Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100037 China

Background The present study was aimed to compare the effects of bilateral and unilateral bidirectional superior cavopulmonary shunt （b-BDG and u-BDG） on pulmonary artery growth and clinical outcomes. Methods The 51 subjects enrolled in this study were divided into two groups： those receiving b-BDG （n=21） and those receiving u-BDG （n=30）. Clinical records were reviewed retrospectively at a mean of 43.3 months after BDG procedures. Chi square and t-tests were performed to analyze the data. Results Left and right pulmonary artery diameters increased 27%-37% in both groups. The pulmonary artery index increased 37.2% after b-BDG and 27.0% after u-BDG, b-BDG patients experienced a significant decrease in mean hemoglobin concentration and hematocrit value, and a correlated change in postoperative diameter of left pulmonary artery （LPA） and pulmonary artery index （y=0.2719, x=-1.8278; R=0.564, P=-0.008）. The change ratio of hemoglobin and postoperative LPA were also correlated in b-BDG patients （y= -0.0522x ＋ 0.3539; R=-0.479, P=-0.028）. Only one b-BDG patient versus twelve u-BDG patients needed total cavopulmonary connections 31.8 months after BDG surgery （P=-0.0074）. Moreover, only one （4.8%） b-BDG patient but eight u-BDG patients （26.7%） developed pulmonary arteriovenous malformations. Conclusions b-BDG increases bilateral pulmonary blood flow and promotes growth of bilateral pulmonary arteries, with preferable physiological outcomes to u-BDG. Results may imply that subsequent Fontan repair may not always be needed. Chin Med J 2009; 122（2）： 129-135

关键词： cavopulmonary shunts congenital heart defects cyanosis heart bypass, right pulmonary artery, hypoplasia

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

Significantly Enhanced Energy Storage Performances of PEI-based Composites Utilizing Surface Functionalized ZrO_(2) Nanoparticles for High-Temperature Application

引用

Chinese Journal of Polymer Science 2024年第3期42卷 322-332,I0006页

作者： qing-qing Liu Qiu-Hao Lin Xiao-dong Qi Nan Zhang Ting Huang Jing-Hui Yang yong Wang School of Chemistry Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of Advanced Technologies of Materials Ministry of Education of ChinaSouthwest Jiaotong UniversityChengdu 610031China

Polymer dielectrics with a high energy density and an available energy storage capacity have been playing an important role in advanced electronics and power systems. Nevertheless, the use of polymer dielectrics in harsh environments is limited by their low energy density at high temperatures. Herein, zirconium dioxide(ZrO_(2)) nanoparticles were decorated with amino group utilizing 4,4-methylenebis(phenyl isocyanate)(AMEO) and successfully incorporated into polyetherimide(PEI) matrix. The dielectric properties, breakdown strength, and energy storage performances of PEI/ZrO_(2)-AMEO nanocomposites were investigated from 25 ℃ to 150 ℃. It is found that the combination of moderate bandgap ZrO_(2) with modest dielectric constant and polar groups at interface with deep trap can offer an available strategy to simultaneously increase the dielectric constant and breakdown strength of polymer dielectrics. As a result, the composites containing ZrO_(2)-AMEO exhibit excellent energy storage performance at elevated temperatures. Specially, the PEI-based composites with 3 vol% ZrO_(2)-AMEO display a maximum discharged energy density(U_(d)) of 3.1 J/cm^(3) at 150 ℃, presenting 90% higher than that of neat PEI. This study may help to better develop the polymer-based dielectric composite applied at elevated temperatures.

关键词： Polyetherimide High temperature dielectric ZrO_(2) Interface

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

A New Method for Solving Nonlinear Partial Differential Equations Based on Liquid Time-Constant Networks

引用

Journal of Systems Science & Complexity 2024年第2期37卷 480-493页

作者： SUN Jiuyun dong Huanhe FANG yong College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this paper,physics-informed liquid networks(PILNs)are proposed based on liquid time-constant networks(LTC)for solving nonlinear partial differential equations(PDEs).In this approach,the network state is controlled via ordinary differential equations(ODEs).The significant advantage is that neurons controlled by ODEs are more expressive compared to simple activation *** addition,the PILNs use difference schemes instead of automatic differentiation to construct the residuals of PDEs,which avoid information loss in the neighborhood of sampling *** this method draws on both the traveling wave method and physics-informed neural networks(PINNs),it has a better physical ***,the KdV equation and the nonlinear Schr¨odinger equation are solved to test the generalization ability of the *** the best of the authors’knowledge,this is the first deep learning method that uses ODEs to simulate the numerical solutions of PDEs.

关键词： Nonlinear partial differential equations numerical solutions physics-informed liquid networks physics-informed neural networks

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

Physical informed memory networks for solving PDEs:implementation and applications

引用

Communications in Theoretical Physics 2024年第2期76卷 51-61页

作者： Jiuyun Sun Huanhe dong yong Fang College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

With the advent of physics informed neural networks(PINNs),deep learning has gained interest for solving nonlinear partial differential equations(PDEs)in recent *** this paper,physics informed memory networks(PIMNs)are proposed as a new approach to solving PDEs by using physical laws and dynamic behavior of *** the fully connected structure of the PINNs,the PIMNs construct the long-term dependence of the dynamics behavior with the help of the long short-term memory ***,the PDEs residuals are approximated using difference schemes in the form of convolution filter,which avoids information loss at the neighborhood of the sampling ***,the performance of the PIMNs is assessed by solving the Kd V equation and the nonlinear Schr?dinger equation,and the effects of difference schemes,boundary conditions,network structure and mesh size on the solutions are *** show that the PIMNs are insensitive to boundary conditions and have excellent solution accuracy even with only the initial conditions.

关键词： nonlinear partial differential equations physics informed memory networks physics informed neural networks numerical solution

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

Compound extreme inundation risk of coastal wetlands caused by climate change and anthropogenic activities in the Yellow River Delta,China

引用

Advances in Climate Change Research 2024年第1期15卷 134-147页

作者： Xiao-Li WANG Ai-qing FENG Xi-yong HOU qing-Chen CHAO Bai-Yuan SONG Yu-Bin LIU Qi-Guang WANG He XU Yu-Xin ZHANG dong Li Li-Jie dong Yu GUO CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China Shandong Key Laboratory of Coastal Environmental Processes Yantai 264003China China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Tongji Urban Planning Design Research Institute Shanghai 200092China School of Geography and Tourism Qilu Normal UniversityJinan 250200China China Meteorological Administration Training Centre China Meteorological AdministrationBeijing 10008China University of Chinese Academy of Sciences Beijing 100049China Marine Science and Technology College Zhejiang Ocean UniversityZhoushan 316022China

The coastal wetlands of the Yellow River Delta(YRD)in China are crucial for their valuable resources,environmental significance,and economic ***,these wetlands are also vulnerable to the dual threats of climate change and human *** substantial attention to the historical shifts in YRD's coastal wetlands,uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic *** on a range of remote sensing data sources,this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and ***,the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change(LUCC)simulation using System Dynamic-Future Land Use Simulation(SD-FLUS)model and the extreme water levels projection integrated future sea-level rise,storm surge,and astronomical high tide in 2030,2050,and 2100 under scenarios of SSP1-2.6,SSP2-4.5,and *** revealed that YRD's coastal wetlands underwent a marked reduction,shrinking by 1688.72 km²from 2000 to *** decline was mostly attributed to the substantial expansion in the areas of artificial wetlands(increasing by 823.78 km2),construction land(increasing by 767.71 km²),and shallow water(increasing by 274.58 km²).Looking ahead to 2030-2100,the fate of coastal wetlands appears to diverge based on different *** the SSP1-2.6 scenario,the area of coastal wetland is projected to experience considerable *** contrast,the SSP5-8.5 scenario anticipates a notable decrease in coastal *** to the inundated area suffered from the current extreme water levels,the study projects a decrease of 6.8%-10.6%in submerged coastal wetlands by 2030 and 9.4%-18.2%by 2050 across all *** 2100,these percentages are projected to decrease by 0.4%(SSP2-4.5)and 27.1%(SSP5-8.5),but increase by 35.7%(SSP1-2.6).Results suggest that coastal wetlands in th

关键词： Climate change Anthropogenic activities Compound extreme risk Coastal wetlands Yellow River Delta

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

Machine learning for carbonate formation drilling: Mud loss prediction using seismic attributes and mud loss records

引用

Petroleum Science 2024年第2期21卷 1241-1256页

作者： Hui-Wen Pang Han-qing Wang Yi-Tian Xiao Yan Jin Yun-Hu Lu yong-dong Fan Zhen Nie National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China College of Science China University of Petroleum-BeijingBeijing102249China Petroleum Exploration and Production Research Institute SINOPECBeijing102206China College of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China Research Institute of Petroleum Exploration and Development CNPCBeijing100083China

Due to the complexity and variability of carbonate formation leakage zones, lost circulation prediction and control is one of the major challenges of carbonate drilling. It raises well-control risks and production expenses. This research utilizes the H oilfield as an example, employs seismic features to analyze mud loss prediction, and produces a complete set of pre-drilling mud loss prediction solutions. Firstly, 16seismic attributes are calculated based on the post-stack seismic data, and the mud loss rate per unit footage is specified. The sample set is constructed by extracting each attribute from the seismic trace surrounding 15 typical wells, with a ratio of 8:2 between the training set and the test set. With the calibration results for mud loss rate per unit footage, the nonlinear mapping relationship between seismic attributes and mud loss rate per unit size is established using the mixed density network ***, the influence of the number of sub-Gausses and the uncertainty coefficient on the model's prediction is evaluated. Finally, the model is used in conjunction with downhole drilling conditions to assess the risk of mud loss in various layers and along the wellbore trajectory. The study demonstrates that the mean relative errors of the model for training data and test data are 6.9% and 7.5%, respectively, and that R2is 90% and 88%, respectively, for training data and test data. The accuracy and efficacy of mud loss prediction may be greatly enhanced by combining 16 seismic attributes with the mud loss rate per unit footage and applying machine learning methods. The mud loss prediction model based on the MDN model can not only predict the mud loss rate but also objectively evaluate the prediction based on the quality of the data and the model.

关键词： Lost circulation Risk prediction Machine learning Seismic attributes Mud loss records

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

Vertically grown MoS_(2)nanosheets on graphene with defect-rich structure for efficient sodium storage

引用

Rare Metals 2024年第3期43卷 1062-1071页

作者： Ying Wang Jia-Peng He Han-qing Pan qing-Peng Wang Lei Zhang yong-Chang Liu qing-Hong Wang School of Chemistry&Materials Science Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal UniversityXuzhou221116China Institute of Biopharmaceutical Research Liaocheng UniversityLiaocheng252059China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyState Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing100083China Centre for Catalysis and Clean Energy Gold Coast CampusGriffith UniversityGold CoastQLD4222Australia

The synthesis of a perpendicular growth structure of MoS_(2)nanosheets on graphene for efficient sodium storage is challenging yet ideal due to the benefits of open ion diffusion channels and high electronic *** this study,we have successfully fabricated a novel structure of vertical MoS_(2)nanosheets on graphene,with ZnS nanoparticles serving as bonding points(MoS_(2)/ZnS/G),through a facile hydrothermal *** the synthesis process,Zn^(2+)not only acts as a landing site for the vertical growth of MoS_(2)nanosheets but also triggers the formation of a defect-rich structure in the final *** unique architecture of MoS_(2)/ZnS/G effectively combines the advantages of a vertically aligned geometry and a defectrich structure for energy *** resulting structure displays shortened transport paths for electrons/ions,enhanced conductivity,improved structural integrity,and an increased number of active sites for promising electrochemical *** expected,when used as anode for sodium-ion batteries,the as-synthesize d MoS_(2)/ZnS/G exhibits excellent rate capability(high capacity of 298 mAh·g^(-1)at 5 A·g^(-1))and good cycling stability(a capacity decay of 0.056%per cycle after 500 cycles at 1 A·g^(-1)).According to the kinetic investigations,the electrochemical process of the MoS_(2)/ZnS/G sample is primarily governe d by a pseudocapacitive behavior,which enhances the charge/discharge kinetics and allows the MoS_(2)/ZnS/G structure to remain intact during cycling.

关键词： MoS_(2) Perpendicular growth Graphene Sodium storage Electrochemical performance

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

Design and performance evaluation of a large field-of-view dual-particle time-encoded imager based on a depth-of-interaction detector

引用

Nuclear Science and Techniques 2024年第4期35卷 1-14页

作者： dong Zhao Xu-Wen Liang Ping-Kun Cai Wei Cheng Wen-Bao Jia Da-Qian Hei qing Shan yong-Sheng Ling Chao Shi Department of Nuclear Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions Suzhou 215000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Time-encoded imaging is useful for identifying potential special nuclear materials and other radioactive sources at a *** this study,a large field-of-view time-encoded imager was developed for gamma-ray and neutron source hotspot imaging based on a depth-of-interaction(DOI)*** imager primarily consists of a DOI detector system and a rotary dual-layer cylindrical coded *** EJ276 plastic scintillator coupled with two SiPMs was designed as the DOI detector to increase the field of view and improve the imager *** difference in signal time at both ends and the log of the signal amplitude ratio were used to calculate the interaction position *** position resolution of the DOI detector was calibrated using a collimated Cs-137 source,and the full width at half maximum of the reconstruction position of the Gaussian fitting curve was approximately 4.4 *** DOI detector can be arbitrarily divided into several units to independently reconstruct the source distribution *** unit length was optimized via Am-Be source-location experiments.A multidetector filtering method is proposed for image *** method can effectively reduce image noise caused by poor DOI detector position *** vertical field of view of the imager was(-55°,55°)when the detector was placed in the center of the coded mask.A DT neutron source at 20 m standoff could be located within 2400 s with an angular resolution of 3.5°.

关键词： Time-encoded imager Depth-of-interaction detector Dual-particle imaging Hotspot imaging

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

Time-domain dynamic constitutive model suitable for mucky soil site seismic response

引用

Earthquake Engineering and Engineering Vibration 2024年第1期23卷 1-13页

作者： dong qing Chen Su Jin Liguo Zhou Zhenghua Li Xiaojun Architectural Engineering Institute Huaiyin Institute of TechnologyHuai’an 223600China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100020China Institute of Geophysics China Earthquake AdministrationBeijing 100089China College of Transportation Science and Engineering Nanjing Tech UniversityNanjing 211816China

Soil nonlinear behavior displays noticeable effects on the site seismic *** study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton *** integrating shear modulus and combining the dynamic skeleton curve and the damping degradation coefficient,the constitutive equation of the logarithmic dynamic skeleton can be obtained,which considers the damping effect in a soil dynamics *** on the finite difference method and the multi-transmitting boundary condition,a 1D site seismic response analysis program called Soilresp1D has been developed herein and used to analyze the time-domain seismic response in three types of *** the same time,this study also provides numerical simulation results based on the hyperbolic constitutive model and the equivalent linear *** results verify the rationality of the new soil dynamic constitutive *** can analyze the mucky soil site nonlinear seismic response,reflecting the deformation characteristics and damping effect of the silty *** hysteresis loop area is more extensive,and the residual strain is evident.

关键词： seismic response time-domain dynamic constitutive model logarithmic dynamic skeleton dampening effect mucky soil

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：