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Analysis of spatial distribution characteristics and driving factors of ethnicminority villages in China using geospatial technology and statistical models
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作者 SHAO Dandan ZOH Kyungjin 《Journal of Mountain Science》 SCIE CSCD 2024年第8期2770-2789,共20页
This study aims to reveal the spatial structural characteristics of 1,652 Ethnic-Minority Villages(EMV)in China and to analyze the mechanisms driving their spatial heterogeneity.EMV are a special type of settlement sp... This study aims to reveal the spatial structural characteristics of 1,652 Ethnic-Minority Villages(EMV)in China and to analyze the mechanisms driving their spatial heterogeneity.EMV are a special type of settlement space that preserve a large number of historical traces of the ethnic culture of ancient China.They are important carriers of China’s excellent traditional culture and are key to the implementation of rural revitalization strategies.In this study,1652 EMV in China were selected as the research subjects.The Nearest Neighbor Index,kernel density,and spatial autocorrelation index were employed to reveal the spatial structural characteristics of minority villages.Neural network models,spatial lag models,and geographical detectors were used to analyze the formation mechanism of spatial heterogeneity in EMV.The results indicate that:(1)EMV exhibit significant spatial differentiation characterized by“single-core with multiple surrounding sub-centers,”“polarization between east and west,”“decreasing quantity from southwest to east coast to northeast to northwest,”and“large dispersion with small agglomeration.”(2)EMV are mainly distributed in areas rich in intangible cultural heritage,with high vegetation coverage and low altitude,far from central cities,and having limited arable land and an underdeveloped economy and transportation,particularly in shaded or riverbank areas.(3)Distance from the nearest river(X3),distance from central cities(X8),national intangible cultural heritage(X9),and NDVI(X10)were the main driving factors affecting the spatial distribution of EMV,whereas elevation(X1)and GDP(X5)had the weakest influence.As EMV are a relatively unique territorial spatial unit,the identification of their spatial heterogeneity characteristics not only deepens the research content of settlement geography,but also involves the assessment,protection,and development of Minority Villages,which is of great significance for the inheritance and utilization of excellent ethnic cultures in the era. 展开更多
关键词 Ethnic-Minority villages Spatial structure Settlement geography Neural network model Spatial econometric model GeoDetector
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Endoscopic diagnosis and management of gallbladder carcinoma in minimally invasive era:New needs,new models
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作者 La-Cuo Deqing Jun-Wen Zhang Jian Yang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第11期4333-4337,共5页
Gallbladder cancer(GBC)is a rare and lethal malignancy;however,it represents the most common type of biliary tract cancer.Patients with GBC are often diagnosed at an advanced stage,thus,unfortunately,losing the opport... Gallbladder cancer(GBC)is a rare and lethal malignancy;however,it represents the most common type of biliary tract cancer.Patients with GBC are often diagnosed at an advanced stage,thus,unfortunately,losing the opportunity for curative surgical intervention.This situation leads to lower quality of life and higher mortality rates.In recent years,the rapid development of endoscopic equipment and techniques has provided new avenues and possibilities for the early and minimally invasive diagnosis and treatment of GBC.This editorial comments on the article by Pavlidis et al.Building upon their work,we explore the new needs and corresponding models for managing GBC from the endoscopic diagnosis and treatment perspective. 展开更多
关键词 ENDOSCOPY Diagnosis and treatment Gallbladder carcinoma Minimal invasive new need new model
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Construction of the underlying circRNA-miRNA-mRNA regulatory network and a new diagnostic model in ulcerative colitis by bioinformatics analysis
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作者 Yu-Yi Yuan Hui Wu +2 位作者 Qian-Yun Chen Heng Fan Bo Shuai 《World Journal of Clinical Cases》 SCIE 2024年第9期1606-1621,共16页
BACKGROUND Circular RNAs(circRNAs)are involved in the pathogenesis of many diseases through competing endogenous RNA(ceRNA)regulatory mechanisms.AIM To investigate a circRNA-related ceRNA regulatory network and a new ... BACKGROUND Circular RNAs(circRNAs)are involved in the pathogenesis of many diseases through competing endogenous RNA(ceRNA)regulatory mechanisms.AIM To investigate a circRNA-related ceRNA regulatory network and a new predictive model by circRNA to understand the diagnostic mechanism of circRNAs in ulcerative colitis(UC).METHODS We obtained gene expression profiles of circRNAs,miRNAs,and mRNAs in UC from the Gene Expression Omnibus dataset.The circRNA-miRNA-mRNA network was constructed based on circRNA-miRNA and miRNA-mRNA interactions.Functional enrichment analysis was performed to identify the biological mechanisms involved in circRNAs.We identified the most relevant differential circRNAs for diagnosing UC and constructed a new predictive nomogram,whose efficacy was tested with the C-index,receiver operating characteristic curve(ROC),and decision curve analysis(DCA).RESULTS A circRNA-miRNA-mRNA regulatory network was obtained,containing 12 circRNAs,three miRNAs,and 38 mRNAs.Two optimal prognostic-related differentially expressed circRNAs,hsa_circ_0085323 and hsa_circ_0036906,were included to construct a predictive nomogram.The model showed good discrimination,with a C-index of 1(>0.9,high accuracy).ROC and DCA suggested that the nomogram had a beneficial diagnostic ability.CONCLUSION This novel predictive nomogram incorporating hsa_circ_0085323 and hsa_circ_0036906 can be conveniently used to predict the risk of UC.The circRNa-miRNA-mRNA network in UC could be more clinically significant. 展开更多
关键词 Circular RNAs RNA regulatory network Ulcerative colitis new predictive model BIOINFORMATICS DIAGNOSE
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Electromechanical Transient Modeling Analysis of Large-Scale New Energy Grid Connection
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作者 Shichao Cao Yonggang Dong Xiaoying Liu 《Energy Engineering》 EI 2024年第4期1109-1125,共17页
The synchronous virtual machine uses inverter power to imitate the performance of the conventional synchronous machine.It also has the same inertia,damping,frequency,voltage regulation,and other external performance a... The synchronous virtual machine uses inverter power to imitate the performance of the conventional synchronous machine.It also has the same inertia,damping,frequency,voltage regulation,and other external performance as the generator.It is the key technology to realize new energy grid connections’stable and reliable operation.This project studies a dynamic simulation model of an extensive new energy power system based on the virtual synchronous motor.A new energy storage method is proposed.The mathematical energy storage model is established by combining the fixed rotor model of a synchronous virtual machine with the charge-discharge power,state of charge,operation efficiency,dead zone,and inverter constraint.The rapid conversion of energy storage devices absorbs the excess instantaneous kinetic energy caused by interference.The branch transient of the critical cut set in the system can be confined to a limited area.Thus,the virtual synchronizer’s kinetic and potential energy can be efficiently converted into an instantaneous state.The simulation of power system analysis software package(PSASP)verifies the correctness of the theory and algorithm in this paper.This paper provides a theoretical basis for improving the transient stability of new energy-connected power grids. 展开更多
关键词 new energy grid connection transient electromechanical modeling synchronous virtual machine PSASP software energy storage
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A Study on Rural Cultural Communication of Short Videos From the Perspective of Mediation-Taking the Popularization of “Village BA” (Village Basketball Association) in Qiandongnan as an Example
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作者 SHEN Lei JIA Peng WEI Xiaojia 《Journalism and Mass Communication》 2024年第3期209-214,共6页
With the rise of new media and short videos shaping the new communication environment,rural culture has been mediated and transformed to spread to a wider region.As a cultural achievement of rural revitalization,“Vil... With the rise of new media and short videos shaping the new communication environment,rural culture has been mediated and transformed to spread to a wider region.As a cultural achievement of rural revitalization,“Village BA”(Village Basketball Association)demonstrates Chinese modernization.The use of short videos,mass rural movements,and“spectacle”spaces to attract spectators has become a key issue in the dissemination of rural culture. 展开更多
关键词 new media mediated rural culture short video village BA”
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Study on the Construction and Evaluation System of Clinical Midwifery Teaching Faculty under the New Nursing Model
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作者 Ying Zhou Xiwei Zhang +2 位作者 Lijun Song Yingying Xiao Hua Zhang 《Journal of Clinical and Nursing Research》 2024年第7期35-41,共7页
Objective:To explore the impact of the construction of a clinical midwifery teaching faculty and the development of an evaluation system under the new nursing model on the current teaching quality.Methods:From July 20... Objective:To explore the impact of the construction of a clinical midwifery teaching faculty and the development of an evaluation system under the new nursing model on the current teaching quality.Methods:From July 2022 to March 2023,10 clinical teaching teachers and 20 midwifery interns from Beijing Anzhen Hospital affiliated with Capital Medical University were selected as the subjects of this study.The clinical teaching teachers and midwifery interns were divided into an observation group and a control group,with each group including 5 clinical teaching teachers and 10 midwifery interns.The observation group received daily management and evaluation under the new nursing model,while the control group received management and evaluation under the traditional nursing model.The teaching quality evaluation of clinical midwifery teaching teachers by midwifery interns,the exit exam scores of midwifery interns,and the scores of clinical teaching teachers’internship lectures and teaching rounds were compared between the two groups.Results:In the observation group,the scores for teaching attitude,teaching skills,and teaching management in the teaching quality evaluation of clinical midwifery teaching teachers were higher than those in the control group.The professional theory scores(91.28±3.64)and overall nursing comprehensive scores(92.56±4.38)of midwifery interns in the observation group were higher than those of midwifery interns in the control group(81.58±2.27 and 80.29±3.33,respectively).The scores for internship lectures(89.32±4.15)and teaching rounds(90.64±5.52)in the observation group were also significantly higher than those in the control group(80.46±3.28 and 81.24±4.38,respectively),and the differences were statistically significant(P<0.05).Conclusion:The management of the clinical midwifery teaching faculty under the new nursing model effectively improved the quality of clinical teaching.It significantly enhanced the teaching effectiveness of clinical teaching teachers and the proficiency of midwifery interns in clinical operations,making it worthy of promotion and use. 展开更多
关键词 Clinical teaching Teaching faculty new nursing model Evaluation system
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Economic Analysis and Research of New Energy Vehicle Promotion Model
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作者 Zihang Wang Xudong Wang +2 位作者 Zhenyin Zhang Shaolong Wang Chenyang Xu 《Proceedings of Business and Economic Studies》 2024年第1期169-179,共11页
New energy vehicles represent the inevitable trend of future development.Compared to traditional fuel vehicles,they are more energy-saving and environmentally friendly,effectively reducing air pollution and mitigating... New energy vehicles represent the inevitable trend of future development.Compared to traditional fuel vehicles,they are more energy-saving and environmentally friendly,effectively reducing air pollution and mitigating excessive exploitation of oil resources,a stance strongly supported by governments.However,new energy vehicles possess certain drawbacks in terms of price and usability compared to traditional counterparts.Therefore,external support is imperative for their development.This paper delineates four main sections:the background of new energy vehicle promotion and application,a comparative analysis of domestic and foreign promotion models,specific promotion suggestions,and future development prospects.By leveraging insights from economic analysis,the optimal promotion model for new energy vehicles is elucidated. 展开更多
关键词 new energy vehicle engineering Promotion model Economic analysis Sustainable development
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Remodeling of Rural Public Service Supply Mechanism under the Background of New Village Construction 被引量:2
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作者 LU Mei 《Asian Agricultural Research》 2011年第7期50-53,共4页
Under the background of new village construction, the necessity of remodeling the supply mechanism of rural public service is expounded. It is conducive to improving the capability of public service to satisfy farmers... Under the background of new village construction, the necessity of remodeling the supply mechanism of rural public service is expounded. It is conducive to improving the capability of public service to satisfy farmers' demand; to constructing a rural diversified public service system and improving the supply efficiency of rural public goods; to realizing the equalization of urban-rural public services to coordinate urban-rural development. Problems in the supply of Chinese rural public services are analyzed:the demand of rural public goods is enormous, governmental fiscal expenditure is insufficient; social organization is imperfect and public service capability is weak; urban-rural gap is large and the supply of pubic service is unequal; the system of rural public service is single and the functions are imperfect; the market degree of rural public service is low and the efficiency needs improving. In view of these problems, the strategies for remodeling the supply mechanism of rural public service are put forward, covering intensifying the input intensity of the government, expanding the coverage of public services; vigorously supporting the development of social organization and improving its capability of public goods; breaking through dual system and realizing the equalization of urban-rural public service; perfecting rural diversified public services and perfecting its public service functions; promoting the market progress of rural public services and improving the efficiency of public service. 展开更多
关键词 new village construction Rural public service Supply mechanism REmodelING China
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“SUSPENDING VILLAGE”——A MODEL OF NEW DEVELOPED AREA IN NINGXIA OF CHINA
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作者 Wang Yiming Niu Huien Ningxia Regional Management Office, Yinchuan, Ningxia,750001 P. R. China Dept. of Town and Country Planning, Univ. of Newcastle uponTyne, Newcastle NE1 7RU, UK 《干旱区资源与环境》 CSCD 1993年第Z1期441-444,共4页
Ningxia is located in the Northwest China. The Huanghe (Yellow River) flowsthrough from its middle--west to the north. It is a province in which the Chinese Muslim--Hui Nationality is concentrated, with about one thir... Ningxia is located in the Northwest China. The Huanghe (Yellow River) flowsthrough from its middle--west to the north. It is a province in which the Chinese Muslim--Hui Nationality is concentrated, with about one third of the total population, hence theNingxia Hui Autonomous Region. From 1983 to 1992, more than 200000 people 展开更多
关键词 “Suspending village POPULATION OVERLOAD PEOPLE MIGRATION model
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Environmental Planning of New Countryside with Dazhuang Village in Pingdingshan City as an Example
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作者 李合章 《Journal of Landscape Research》 2010年第2期7-10,共4页
The paper introduced regulation and planning situation of Dazhuang Village which was the experiment construction project in Pindingshan City, and offered several proposals for the construction of the village's reg... The paper introduced regulation and planning situation of Dazhuang Village which was the experiment construction project in Pindingshan City, and offered several proposals for the construction of the village's regulation and planning. 展开更多
关键词 Coal mine area new countryside Regulation and planning of village
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Research on Internal Relevance between New Farmers and New Village Construction 被引量:2
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作者 YIN Rui-hang,GAO Zheng-li School of Political Science and Law,Anhui Normal University,Wuhu 241000,China 《Asian Agricultural Research》 2011年第4期128-131,共4页
On the basis of Marxist theories,from the perspective that the new farmers are the qualified main body,basic factors and internal motive force of constructing new village,this paper expounds the internal relevance bet... On the basis of Marxist theories,from the perspective that the new farmers are the qualified main body,basic factors and internal motive force of constructing new village,this paper expounds the internal relevance between new farmers and new village construction.Firstly,the new farmers have insight into villages,with strong motive of constructing new village,which makes them become the qualified main body in new village construction.Secondly,the new farmers are the most basic factor of constructing new village;new farmers have close relationship with other factors,with prominent inseparability;the new farmers have strong ability to replace other factors,and the farmers can shatter capital bottleneck and policy restriction in order to promote rural development to some extent;the new farmers with strong mobility,can migrate between city and village or change vocation among different jobs,which breaks through the regional limitation of factors;there are myriad farmers in China,and we can transform traditional farmers into new farmers by fostering,which breaks through the limitation of quantity of factors,so it can guarantee the incessant factor supply for new village construction.Thirdly,the new farmers are the internal motive force for new village construction,because the literate farmers are equipped with technique skills and good at management,and they are the excellent talents among rural groups;the new farmers fathom the characteristics of rural areas,with active consciousness,intense motive and strong ability to construct new village;they pay close attention to new village construction with passion and participate in new village construction actively. 展开更多
关键词 new village construction new FARMERS MAIN BODY Fac
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The Role Played by Agricultural Policy-based Finance in New Village Construction 被引量:3
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作者 LI Ning-hua 《Asian Agricultural Research》 2011年第1期55-59,共5页
The necessity of the agricultural policy-based finance in terms of supporting the new village construction is analyzed: in the first place, the theoretical roots of agricultural policy-based finance supporting new vil... The necessity of the agricultural policy-based finance in terms of supporting the new village construction is analyzed: in the first place, the theoretical roots of agricultural policy-based finance supporting new village construction are "market failure" and "government intervention"; in the second place, the continual decline of agriculture and the "rural financial market failure" in recent years have become the objective evidence and historical mission for agricultural policy-based finance to support new village construction; in the third place, the combination of agricultural policy-based finance and new village construction is conducive to solving the "three agriculture" problems and facilitating the reform of new village construction. The feasibility of the support is analyzed: firstly, agricultural policy-based finance boasts the status and position of the "primary drive" in new village construction; secondly, the nation continuously deepens the reform of rural financial system and policy-based banks and strengthens the functions of Agricultural Development Bank, which provides policies for agricultural policy-based finance to support new village construction; thirdly, the 14 years' reform and development of Agricultural Development Bank and the eleventh five year plan lay sound practical basis for the support of agricultural policy-based finance to new village construction. Based on the necessity and feasibility, the following six aspects are analyzed to fully display the function of the "first engine" of agricultural policy-related finance to new village construction. Firstly, strengthening the credit and loan aid to grain and cotton and some other agricultural products in the circulation domain; secondly, strengthening the credit and loan aid to agricultural industrialization in processing field; thirdly, intensifying the credit and loan aid to agricultural comprehensive development, rural infrastructure construction, application and promotion of agricultural technology, agricultural production means and agricultural ecological construction; fourthly, intensifying the credit and loan aid to rural special group and regional development; fifthly, intensifying the credit and loan aid to agriculture and rural emergency response system and social security system; sixthly, strengthening the credit and loan aid to agriculture and the intermediary construction of rural financial services. 展开更多
关键词 Agricultural policy-based finance new village construction Market failure Fund recycling ROLE China
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Evaluation of Tourism Status in Sustainable Rural Development by Reynard Model (Case Study: Pa Ghaleh Village, Mamasani County, Iran) 被引量:2
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作者 Ali Shamsoddini 《Open Journal of Ecology》 2015年第3期80-85,共6页
The greatest service industry and income gainer throughout the world occupies a special role and position in developing geographical areas. This study attempts to use “Reynard” model to investigate the role of touri... The greatest service industry and income gainer throughout the world occupies a special role and position in developing geographical areas. This study attempts to use “Reynard” model to investigate the role of tourism and its effects on the development of rural settlements with emphasis on Pa Ggaleh Village, which is one of the environs in Mamasani, Iran. Due to its historical and religious attractions and natural and cultural landscapes, this village is highly significant and has the potential to become a tourism hub and attract tourists. The methodology applied in this research is cross-sectional. Tourism potentials of Pa Ghaleh village are identified and evaluated in this study. Geological maps, topographies and field data are used to evaluate the district attractions. Their tourism potentials are also evaluated and rated using Reynard model. According to the sub-criteria of rarity and historical geography, the research results indicate that scientific value has the highest rank. In other words, tourism places in Pa Ghaleh village include 72% of scientific value, 0.59% of added value and 0.57% of compound value. 展开更多
关键词 RURAL TOURISM SUSTAINABLE RURAL Development Reynard model PA Ghaleh village
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Structure of the Quarks and a New Model of Protons and Neutrons: Answer to Some Open Questions
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作者 Ágnes Cziráki 《Natural Science》 CAS 2023年第1期11-18,共8页
The described structural model tries to answer some open questions such as: Why do quarks not exist in the open state? Where are the antiparticles from the Big Bang?
关键词 Structure of Quarks new model PROTON Neutron Open Questions
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Simulation Analysis of New Energy Vehicle Engine Cooling System Based on K-E Turbulent Flow Mathematical Model
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作者 Hongyu Mu Yinyan Wang +7 位作者 Chuanlei Yang Hong Teng Xingtian Zhao Hongquan Lu Dechun Wang Shiyang Hao Xiaolong Zhang Yan Jin 《Energy Engineering》 EI 2023年第10期2325-2342,共18页
New energy vehicles have better clean and environmental protection characteristics than traditional fuel vehicles.The new energy engine cooling technology is critical in the design of new energy vehicles.This paper us... New energy vehicles have better clean and environmental protection characteristics than traditional fuel vehicles.The new energy engine cooling technology is critical in the design of new energy vehicles.This paper used oneand three-way joint simulation methods to simulate the refrigeration system of new energy vehicles.Firstly,a k-εturbulent flow model for the cooling pump flow field is established based on the principle of computational fluid dynamics.Then,the CFD commercial fluid analysis software FLUENT is used to simulate the flow field of the cooling pump under different inlet flow conditions.This paper proposes an optimization scheme for new energy vehicle engines’“boiling”phenomenon under high temperatures and long-time climbing conditions.The simulation results show that changing the radiator’s structure and adjusting the thermostat’s parameters can solve the problem of a“boiling pot.”The optimized new energy vehicle engine can maintain a better operating temperature range.The algorithm model can reference each cryogenic system component hardware selection and control strategy in the new energy vehicle’s engine. 展开更多
关键词 new energy vehicle new energy vehicle engine k-ε turbulent flow mathematical model cooling system PID control
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Circular Economy in New Village Construction——A Case of Qinhuangdao City, China 被引量:1
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作者 LI Tao LIN Peng ZHAO Meng 《Asian Agricultural Research》 2011年第1期48-50,71,共4页
On the strength of the theory of agricultural circular economy, the mutual relation between the development of agricultural circular economy and new village construction is analyzed. The results show that developing a... On the strength of the theory of agricultural circular economy, the mutual relation between the development of agricultural circular economy and new village construction is analyzed. The results show that developing agricultural circular economy and constructing new village is the mutual promotion; realizing agricultural circular economy is the main target of new agricultural construction and developing agricultural circular economy is the way of realizing new village construction. The major problems in the development of agricultural circular economy in Qinhuangdao City are pointed out, covering weak ideological foundation of developing agricultural circular economy; inadequate directions from the government and insufficient technical and financial support. The countermeasures on developing agricultural circular economy in new village construction are put forward, including cultivating people's awareness on circular economy; establishing the law and regulation system of agricultural circular economy; intensifying the technical and model innovation of agricultural circular economy and accelerating the maketization pace of agro-products. 展开更多
关键词 Three agricultural economy new village construction Agricultural circular economy Qinhuangdao City China
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A New Model of Software Engineering Education and Exploration of Professional Curriculum Teaching
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作者 Qingzhen Xu Mingzhi Mao Niansheng Cheng 《计算机教育》 2023年第12期150-157,共8页
This paper focuses on the problems,opportunities,and challenges faced by software engineering education in the new era.We have studied the core ideas of the new model and reform,the specific measures implemented,and t... This paper focuses on the problems,opportunities,and challenges faced by software engineering education in the new era.We have studied the core ideas of the new model and reform,the specific measures implemented,and the challenges and solutions faced.The new model and reform must focus on cultivating practical abilities,introducing interdisciplinary knowledge,and strengthening innovation awareness and entrepreneurial spirit.The process of reform and innovation is carried out from the aspects of teaching methods,teaching means,and course performance evaluation in the teaching practice of software engineering courses.We adopt a method of“question guiding,simple and easy to understand,flexible and diverse,and emphasizing practical results”,optimizing the curriculum design,providing diverse learning opportunities,and establishing a platform for the industry-university-research cooperation.Our teaching philosophy is to adhere to the viewpoint of innovative teaching ideas,optimizing teaching methods and teaching means,and comprehensively improving the teaching quality and level of software engineering education. 展开更多
关键词 Software engineering education new model Professional course teaching
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A new mixed-mode phase-field model for crack propagation of brittle rock
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作者 Qiuhua Rao Chenchen Zhao Wei Yi 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第5期1186-1199,共14页
Study on crack propagation process of brittle rock is of most significance for cracking-arrest design and cracking-network optimization in rock engineering.Phase-field model(PFM)has advantages of simplicity and high c... Study on crack propagation process of brittle rock is of most significance for cracking-arrest design and cracking-network optimization in rock engineering.Phase-field model(PFM)has advantages of simplicity and high convergence over the common numerical methods(e.g.finite element method,discrete element method,and particle manifold method)in dealing with three-dimensional and multicrack problems.However,current PFMs are mainly used to simulate mode-I(tensile)crack propagation but difficult to effectively simulate mode-II(shear)crack propagation.In this paper,a new mixed-mode PFM is established to simulate both mode-I and mode-II crack propagation of brittle rock by distinguishing the volumetric elastic strain energy and deviatoric elastic strain energy in the total elastic strain energy and considering the effect of compressive stress on mode-II crack propagation.Numerical solution method of the new mixed-mode PFM is proposed based on the staggered solution method with self-programmed subroutines UMAT and HETVAL of ABAQUS software.Three examples calculated using different PFMs as well as test results are presented for comparison.The results show that compared with the conventional PFM(which only simulates the tensile wing crack but not mode-II crack propagation)and the modified mixed-mode PFM(which has difficulty in simulating the shear anti-wing crack),the new mixed-mode PFM can successfully simulate the whole trajectories of mixed-mode crack propagation(including the tensile wing crack,shear secondary crack,and shear anti-wing crack)and mode-II crack propagation,which are close to the test results.It can be further extended to simulate multicrack propagation of anisotropic rock under multi-field coupling loads. 展开更多
关键词 new mixed-mode phase-field model(PFM) Mode-I and mode-II crack propagation Volumetric strain energy Deviatoric elastic strain energy Compressive stress Brittle rock
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Parameters of new three-water model based on nuclear magnetic experiment and optimization algorithm
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作者 KANG Nan HONG Xin +3 位作者 ZHANG Lihua PAN Baozhi TANG Lei ZHANG Pengji 《Global Geology》 2023年第1期57-62,共6页
Clastic rock reservoir is the main reservoir type in the oil and gas field.Archie formula or various conductive models developed on the basis of Archie’s formula are usually used to interpret this kind of reservoir,a... Clastic rock reservoir is the main reservoir type in the oil and gas field.Archie formula or various conductive models developed on the basis of Archie’s formula are usually used to interpret this kind of reservoir,and the three-water model is widely used as well.However,there are many parameters in the threewater model,and some of them are difficult to determine.Most of the determination methods are based on the statistics of large amount of experimental data.In this study,the authors determine the value of the parameters of the new three-water model based on the nuclear magnetic data and the genetic optimization algorithm.The relative error between the resistivity calculated based on these parameters and the resistivity measured experimentally at 100%water content is 0.9024.The method studied in this paper can be easily applied without much experimental data.It can provide reference for other regions to determine the parameters of the new three-water model. 展开更多
关键词 new three-water model optimization algorithm NMR water saturation rock electric parameters
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Numerical analysis of high‑speed railway slab tracks using calibrated and validated 3D time‑domain modelling
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作者 A.F.Esen O.Laghrouche +4 位作者 P.K.Woodward D.Medina‑Pineda Q.Corbisez J.Y.Shih D.P.Connolly 《Railway Engineering Science》 EI 2024年第1期36-58,共23页
Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a ... Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus.It is then compared to the performance of a ballasted track.First,slab and ballasted track models are developed to replicate the full-scale testing of track sections.Once the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track results.The slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the models.Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical speeds.Various train loading methods are discussed,and the most practical approach is retained and described.Moreover,correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards.It is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds. 展开更多
关键词 High-speed railways Slab track new ballastless track Ballasted track Critical speeds Finite element modelling Calibration of numerical models
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