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Science China Mathematics 2024年第7期67卷 1641-1664页

作者： Jinye Shen Fanhai Zeng Martin Stynes School of Mathematics Southwestern University of Finance and EconomicsChengdu611130China School of Mathematics Shandong UniversityJinan250100China Applied and Computational Mathematics division Beijing Computational Science Research CenterBeijing100193China

Fractional initial-value problems(IVPs) and time-fractional initial-boundary value problems(IBVPs), each with a Caputo temporal derivative of order α ∈(0, 1), are considered. An averaged variant of the well-known L1 scheme is proved to be O(N^(-2)) convergent for IVPs on suitably graded meshes with N points, thereby improving the O(N^(-(2-α))) convergence rate of the standard L1 scheme. The analysis relies on a delicate decomposition of the temporal truncation error that yields a sharp dependence of the order of convergence on the degree of mesh grading used. This averaged L1 scheme can be combined with a finite difference or piecewise linear finite element discretization in space for IBVPs, and under a restriction on the temporal mesh width, one gets again O(N^(-2)) convergence in time, together with O(h^(2)) convergence in space,where h is the spatial mesh width. Numerical experiments support our results.

关键词： time-fractional subdiffusion averaged L1 scheme

How Does Participation in Agricultural Cooperatives Affect the Performance of Family Farms?——Empirical Evidence from 553 Planting Family Farms in Xinjiang Corps

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Journal of Systems Science and Information 2024年

作者： Zhiping HUANG Na LI Xishan Farmland The 12th Division of Xinjiang Production and Construction Corps School of economics and Management University of Chinese Academy of Sciences

Participation in agricultural cooperative organizations is an important form of industrial chain organization expansion, but also an important way to effectively reduce industrial chain transaction costs and promote the quality and efficiency improvement of new agricultural business *** on the micro-survey data of 553 family farms in Xinjiang Corps in 2021, this paper uses stochastic frontier approach to measure the business performance of family farms in Xinjiang Corps, and discusses the action mechanism and difference in the influence of participation in agricultural cooperative organizations on the business performance of family farms. The research shows that participation in agricultural cooperative organizations can significantly improve the business performance of family farms through such mechanisms as easing the constraints of farm credit financing, reducing the transaction costs of agricultural products, and promoting the adoption of agricultural technologies. Compared with food farms, cotton and fruit and vegetable family farms have more obvious performance improvement in participating in agricultural cooperative organizations. Moreover, participation in agricultural cooperation organizations has a stronger effect on the performance improvement of farms in northern Xinjiang. It is found that the vertical extension of the industrial chain between”family farm+agricultural cooperative organization” and network marketers, chain supermarkets, industrial leading enterprises and agricultural production and marketing enterprises is conducive to the improvement of the business performance of family farms, among which the performance improvement effect of”family farm+agricultural cooperative organization+network marketers” mode is more obvious. The research provides a scientific reference for deepening the expansion of the industrial chain organization and promoting the quality-oriented growth of family farms in the new era.

关键词：

Construction of Optimal Mixed-Level Uniform Designs

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Journal of Systems Science & Complexity 2024年第2期37卷 841-862页

作者： CHATTERJEE Kashinath LIU Min-Qian QIN Hong YANG Liuqing Department of Population Health Sciences Division of Biostatistics and Data ScienceAugusta UniversityGA 30912USA NITFID LPMC&KLMDASRSchool of Statistics and Data ScienceNankai UniversityTianjin 300071China School of Statistics and Mathematics Zhongnan University of Economics and LawWuhan 430073China

The theory of uniform design has received increasing interest because of its wide application in the field of computer *** generalized discrete discrepancy is proposed to evaluate the uniformity of the mixed-level factorial *** this paper,the authors give a lower bound of the generalized discrete discrepancy and provide some construction methods of optimal mixed-level uniform designs which can achieve this lower *** methods are all deterministic construction methods which can avoid the complexity of stochastic *** saturated mixed-level uniform designs and supersaturated mixed-level uniform designs can be obtained with these ***,the resulting designs are also χ^(2)-optimal and minimum moment aberration designs.

关键词： Generalized discrete discrepancy Hadamard matrix mixed-level design orthogonal array supersaturated design

Evolution of China's Role in the Structure of Global Carbon Emission Transfers:An Empirical Analysis Based on Network Governance

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China & World Economy 2024年第1期32卷 130-166页

作者： Bingbing Zhang Lelan Kong Zhehong Xu Chuanwang Sun School of economics and Management Nanjing Agricultural University Jiangsu Provincial Center for Agricultural Foreign Cooperation and Communication China Paula and Gregory Chow Institute for Studies in economics Xiamen UniversityChina China Center for Energy economics Research School of Economics and MOE Key Laboratory of EconometricsXiamen UniversityChina

This paper reconsiders the roles of China and some developed countries in the network of carbon emission transfers via international trade in value added from a new perspective of network *** search intensity(NSI)and the extended gravity model are used with cross-country panel data to analyze the mechanism of China's engagement in network governance of carbon emission *** results show that from 2000 to 2009,China was a net exporter of carbon emissions,even though it shifted from the semi-periphery to the core in the network of carbon emissions embodied in ***,NSI had a significant positive impact on carbon emissions embodied in *** China's important role in the global production network and division of labor,NSI may also affect industrial structure and the quality of the ecological environment to a large *** study analyses the network governance mechanism of China's participation in global carbon *** results suggest that the technical complexity of export products and product heterogeneity do not change the positive impact of NSI on carbon emissions.

关键词： carbon emission transfers gravity model network governance network search intensity

New Industrialization: Characteristics, System Development and Implementation Pathway

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China Economist 2024年第1期19卷 2-13页

作者：无 Research Group of the Institute of Industrial economics Chinese Academy of Social Sciences(CASS)BeijingChina

New industrialization in China, different from its past economic development pattern or patterns in developed nations, is the country’s theoretical innovation based on the positive and negative experiences of industrialization at home and worldwide. New industrialization has various novel characteristics, including new sources of efficiency, new factors of production, new organizational forms, and new constraints. In addition, it has certain particularities arising from modernization with Chinese characteristics. This article summarizes the characteristics of new industrialization from the perspectives of people-centered approach, quality-first concept, independent innovation, green low-carbon economics, digital-real integration, and open circulation. There are four systems for promoting new industrialization: A self-sustained scientific and technological system, a high-end advanced manufacturing system, a green low-carbon circular system, and a division of labor system with domestic and international circulation. The Chinese new industrialization proposes the pathway and policy measures considering the new global situation and the requirements of new goals of strengthening organization and leadership, reducing factor cost, accelerating independent technological innovation, smoothing domestic and international circulation, and optimizing competition environment.

关键词： New industrialization Chinese modernization system building policy measures

An examination of thematic research,development,and trends in remote sensing applied to conservation agriculture

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International Soil and Water Conservation Research 2024年第1期12卷 77-95页

作者： Zobaer Ahmed Aaron Shew Lawton Nalley Michael Popp V.Steven Green Kristofor Brye Center for Advanced Spatial Technologies University of ArkansasFayettevilleARUSA Environmental Dynamics Program University of ArkansasFayettevilleARUSA Department of Agricultural economics and Agribusiness University of ArkansasFayettevilleARUSA College of Agriculture Arkansas State UniversityJonesboroARUSA University of Arkansas System division of Agriculture Little RockARUSA Department of Crop Soiland Environmental SciencesUniversity of ArkansasFayettevilleARUSA

Conservation agriculture seeks to reduce environmental degradation through sustainable management of agricultural *** the 1990s,agricultural research has been conducted using remote sensing technologies;however,few previous reviews have been conducted focused on different conservation management *** of the previous literature has focused on the application of remote sensing in agriculture without focusing exclusively on conservation practices,with some only providing a narrative review,others using biophysical remote sensing for quantitative estimates of the bio-geo-chemical-physical properties of soils and crops,and few others focused on single agricultural management *** paper used the preferred reporting items for systematic review(PRISMA)methodology to examine the last 30 years of thematic research,development,and trends associated with remote sensing technologies and methods applied to conservation agriculture research at various spatial and temporal scales.A set of predefined key concepts and keywords were applied in three databases:Scopus,Web of Science,and Google Scholar.A total of 188 articles were compiled for initial examination,where 68 articles were selected for final analysis and grouped into cover crops,crop residue,crop rotation,mulching,and tillage *** on conservation agriculture research using remote sensing have been increasing since 1991 and peaked at 10 publications in *** the 68 articles,94%used a pixel-based,while only 6%used an object-based classification *** to 2005,tillage practices were abundantly studied,then crop residue was a focused theme between 2004 and *** 2012 to 2020,the focus shifted again to cover *** spectral indices were used in 76%of the 68 *** examination offered a summary of the new potential and identifies crucial future research needs and directions that could improve the contribution of remote sensing to the provision of long-term operat

关键词： Remote sensing Conservation agriculture Classification algorithm Spatial resolution Satellite Spectral indices PRISMA

Analysis of Innovative Factors in the *** Oil and Gas Revolution and Enlightenment for China

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China Oil & Gas 2024年第1期31卷 46-51页

作者： Bao Chunli Hao Hongna Zhou Yuanyuan Xia Yuhan CNOOC Energy economics Institute

The shale oil and gas revolution is one of the best examples of *** and technological innovation and innovation in management and business models have collectively facilitated the development of shale oil and *** them,theoretical innovation is the foundation,technological innovation is the most important driving force and innovation in management and business models is a powerful guarantee for promoting the scale development of shale oil and *** reveals that the longterm investment by the *** in basic research,along with corresponding fiscal and tax policy guarantees,a highly competitive free market mechanism,and a system of professional collaborative division of labor,have laid a solid foundation for innovation in the *** oil and gas *** recognizing the positive and proactive role of innovation in the shale oil and gas revolution,it is also important to deeply understand the differences that China faces in the exploration of shale oil and gas,in terms of geological resources and policy *** is recommended to enhance the integration of industry,university and research to lay out innovation,strengthen policy support,innovate business models,and pay attention to the development of digitalization and intelligence.

关键词： shale policy collective

Can the integration between urban and rural areas be realized?A new theoretical analytical framework

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Journal of Geographical Sciences 2024年第1期34卷 3-24页

作者： WANG Yi LU Yuqi ZHU Yingming Research Base of Jiangsu Industrial Cluster School of Economics and ManagementNanjing University of Science and TechnologyNanjing 210094China School of Geography Nanjing Normal UniversityNanjing 210023China

Urban-rural integration is an advanced form resulting from the future evolution of urban-rural ***,little research has explored whether urban and rural areas can move from dual segmentation to integrated development from a theoretical or empirical *** on the research framework of welfare economics,which offers an appealing paradigm to frame the underlying game between cities and villages,this study clarifies the ideal state of urban-rural *** then proposes a series of basic assumptions,and constructs a corresponding objective function and its ***,it assesses the possibility of seeing the transmutation from division to integration between urban and rural areas with continuous socio-economic *** authors argue that the ideal state of urban-rural integration should be a Pareto-driven optimal allocation of urban-rural resources and outputs,and the maximization of social welfare in the entire *** on a systematic demonstration using mathematical models,the study proposes that urban and rural areas can enter this ideal integrated development pattern when certain parameter conditions are *** general,this study demonstrates the theoretical logic and scientific foundations of urban-rural integration,enriches theoretical studies about urban-rural relationships,and provides basic theoretical support for large developing countries to build a coordinated and orderly urban-rural community with a shared future.

关键词： urban-rural integration development ideal state parameter conditions welfare economics theoretical framework

Adjustment of Administrative divisions and Upgrading of Industrial Structure in Hefei Metropolitan Area:Taking"Partitions of Chaohu"as a Quasi-natural Experiment

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Asian Agricultural Research 2024年第7期16卷 19-23,27页

作者： Yumin DING School of economics Tongling UniversityTongling 244000China

Administrative regions are an important environment for the operation of China's market *** relevant economic subjects cannot predict the policy of adjustment of administrative divisions and carry out conscious migration behavior,adjustment of administrative divisions can be regarded as a quasi-natural *** three cities of Hefei,Wuhu,and Ma'anshan,which are directly related to the adjustment of the administrative division of Chaohu,are taken as the treatment group,and the seven adjacent cities of Lu'an,Huainan,Chuzhou,Bengbu,Anqing,Chizhou,and Tongling are taken as the control ***-in-Differences method and relevant control variables affecting the upgrading of industrial structure are used to *** test results show that"Partitions of Chaohu"has a significant industrial structure upgrading effect by promoting the optimization of spatial layout,the cross-regional flow of production factors and the effective management of Chaohu Lake *** the same time,the increase of total retail sales of consumer goods,urban fixed assets investment,public utility expenses in science,education,culture and health,and population plays a significant positive role in promoting the upgrading of industrial structure,while foreign direct investment plays a certain inhibition role in the upgrading of industrial *** order to meet the ever-developing space demands and enhance the impact on surrounding areas,the Hefei metropolitan area should be driven by technological innovation,strengthen the integration of industrial chains,improve the business environment and transportation network,and continuously promote the upgrading of industrial structure and the formation and development of new productive forces.

关键词： Adjustment of administrative divisions Upgrading of industrial structure Hefei metropolitan area Quasi-natural experiment

Technological anxiety:Analysis of the impact of industrial intelligence on employment in China

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Chinese Journal of Population,Resources and Environment 2024年第3期22卷 343-355页

作者： Yang Shen Pengfei Zhou Institute of Quantitative economics Huaqiao UniversityXiamen 361021China School of Statistics Huaqiao UniversityXiamen 361021China School of economics and Management Chongqing Normal UniversityChongqing 400131China

Employment is the greatest *** the impact of industrial robotics technology materialized in machines on employment in the digital age is an“icing on the cake”or“adding fuel to the fire”needs further *** study aims to analyze the impact of the installation and application of industrial robots on labor demand in the context of the Chinese ***,from the theoretical logic and the economic development law,this study gives the prior judgment and research hypothesis that industrial intelligence will increase ***,based on the panel data of 269 cities in China from 2006 to 2021,we use the two-way fixed effect model,dynamic threshold model,and two-stage intermediary effect *** objective is to investigate the impact of industrial intelligence on enterprise labor demand and its path *** show that the overall effect of industrial intelligence on the labor force with the installation density index of industrial robots as the proxy variable is the“creation effect”.In other words,advanced digital technology has created additional jobs,and the overall supply of employment in the labor market has *** conclusion is still valid after the endogeneity identification and robustness *** addition,the positive effect has a nonlinear effect on the network *** the installation density of industrial robots exceeds a particular threshold value,the division of labor continues to deepen under the combined action of the production efficiency and compensation effects,which will cause enterprises to increase labor demand *** research showed that industrial intelligence can increase employment by promoting synergistic agglomeration and improving labor price *** study concludes that in the digital China era,the introduction and installation of industrial robots by enterprises can affect the optimal allocation of the labor *** phenomenon has essential experience and reference significance for g

关键词： Artificial intelligence Industrial robot Structural unemployment Dynamic threshold model Industrial agglomeration Factor price distortion