At present,the development of e-commerce is slow for agricultural products in China. Taking agricultural workers as the research object,this paper analyzed factors influencing the implementation of e-commerce of agric...At present,the development of e-commerce is slow for agricultural products in China. Taking agricultural workers as the research object,this paper analyzed factors influencing the implementation of e-commerce of agricultural products. Besides,from the enterprise status,market conditions,and groundings,with the aid of the GEM( Groundings-Enterprises-Markets) model,it evaluated the factors influencing the development of e-commerce of agricultural products. Then,using SPSS software,it analyzed factors and came up with improvement recommendations. The results show that 59% of the respondents are willing to conduct e-commerce,and the status of the enterprises,market conditions and groundings are main factors influencing the implementation of e-commerce of agricultural products. Therefore,it is required to increase industrial concentration,promote cooperation between small and medium-sized enterprises( SMEs),and strengthen infrastructure construction,so as to promote the development of e-commerce of agricultural products.展开更多
Firstly, this paper summarizes concept of the agricultural industrial cluster and GEM model. Then, it analyzes the competitiveness of agricultural industrial clusters in Hubei Province from three aspects, namely, the ...Firstly, this paper summarizes concept of the agricultural industrial cluster and GEM model. Then, it analyzes the competitiveness of agricultural industrial clusters in Hubei Province from three aspects, namely, the foundation, enterprises and market. In the aspect of the foundation, Hubei Province has superior geographical location, rich natural resources, abundant human resources, diversified capital sources, and hardware and software facilities. In the aspect of enterprises, agricultural suppliers (farmers) are relatively scattered in Hubei Province, organizational level of relevant enterprises is constantly improved, and structure and strategy of enterprises are constantly innovated. In the aspect of market, the competition of agricultural products is fierce in local market, and it is difficult to explore external market. Finally, it presents countermeasures to improve the competitiveness of agricultural industrial clusters in Hubei Province, including building agricultural industrial park and cultivating key leading enterprises, strengthening innovation management, and increasing financial support.展开更多
Due to the novel applications of flexible pipes conveying fluid in the field of soft robotics and biomedicine,the investigations on the mechanical responses of the pipes have attracted considerable attention.The fluid...Due to the novel applications of flexible pipes conveying fluid in the field of soft robotics and biomedicine,the investigations on the mechanical responses of the pipes have attracted considerable attention.The fluid-structure interaction(FSI)between the pipe with a curved shape and the time-varying internal fluid flow brings a great challenge to the revelation of the dynamical behaviors of flexible pipes,especially when the pipe is highly flexible and usually undergoes large deformations.In this work,the geometrically exact model(GEM)for a curved cantilevered pipe conveying pulsating fluid is developed based on the extended Hamilton's principle.The stability of the curved pipe with three different subtended angles is examined with the consideration of steady fluid flow.Specific attention is concentrated on the large-deformation resonance of circular pipes conveying pulsating fluid,which is often encountered in practical engineering.By constructing bifurcation diagrams,oscillating shapes,phase portraits,time traces,and Poincarémaps,the dynamic responses of the curved pipe under various system parameters are revealed.The mean flow velocity of the pulsating fluid is chosen to be either subcritical or supercritical.The numerical results show that the curved pipe conveying pulsating fluid can exhibit rich dynamical behaviors,including periodic and quasi-periodic motions.It is also found that the preferred instability type of a cantilevered curved pipe conveying steady fluid is mainly in the flutter of the second mode.For a moderate value of the mass ratio,however,a third-mode flutter may occur,which is quite different from that of a straight pipe system.展开更多
This paper reviewed the main target,functions,tool( Open Quake software) and research achievements of the Global Earthquake Model( GEM) Foundation,and made a simple prospect on the development and application of proje...This paper reviewed the main target,functions,tool( Open Quake software) and research achievements of the Global Earthquake Model( GEM) Foundation,and made a simple prospect on the development and application of projects of GEM in the future. Learning from GEM and Open Quake is helpful to improve the seismic hazard model of China and enhance the scientificity of the seismic hazard assessment for metropolitans and major engineering facilities near major seismogenic structures.展开更多
分析了电阻率和电阻几何系数对基于炭黑/硅橡胶的力敏导电橡胶的"正拉力-电阻特性"(positivetensile coefficient of resistance,PTCR)的影响程度,揭示了力敏导电橡胶拉伸过程的电阻变化机理。在一定拉伸范围内(40%),当导电...分析了电阻率和电阻几何系数对基于炭黑/硅橡胶的力敏导电橡胶的"正拉力-电阻特性"(positivetensile coefficient of resistance,PTCR)的影响程度,揭示了力敏导电橡胶拉伸过程的电阻变化机理。在一定拉伸范围内(40%),当导电填料用量处在渗流区中心时,电阻率的增大是引起PTCR效应的主要原因。随着导电填料用量的增大,电阻几何系数的增大成为引起PTCR效应的主要原因。在某一特定导电填料范围内,力敏导电橡胶的"正拉力-电阻特性"还与拉伸长度有关。拉伸长度较小时,电阻几何系数的增大在PTCR效应中占主导;拉伸长度较大时,电阻率的增大在PTCR效应中占主导。展开更多
文摘At present,the development of e-commerce is slow for agricultural products in China. Taking agricultural workers as the research object,this paper analyzed factors influencing the implementation of e-commerce of agricultural products. Besides,from the enterprise status,market conditions,and groundings,with the aid of the GEM( Groundings-Enterprises-Markets) model,it evaluated the factors influencing the development of e-commerce of agricultural products. Then,using SPSS software,it analyzed factors and came up with improvement recommendations. The results show that 59% of the respondents are willing to conduct e-commerce,and the status of the enterprises,market conditions and groundings are main factors influencing the implementation of e-commerce of agricultural products. Therefore,it is required to increase industrial concentration,promote cooperation between small and medium-sized enterprises( SMEs),and strengthen infrastructure construction,so as to promote the development of e-commerce of agricultural products.
文摘Firstly, this paper summarizes concept of the agricultural industrial cluster and GEM model. Then, it analyzes the competitiveness of agricultural industrial clusters in Hubei Province from three aspects, namely, the foundation, enterprises and market. In the aspect of the foundation, Hubei Province has superior geographical location, rich natural resources, abundant human resources, diversified capital sources, and hardware and software facilities. In the aspect of enterprises, agricultural suppliers (farmers) are relatively scattered in Hubei Province, organizational level of relevant enterprises is constantly improved, and structure and strategy of enterprises are constantly innovated. In the aspect of market, the competition of agricultural products is fierce in local market, and it is difficult to explore external market. Finally, it presents countermeasures to improve the competitiveness of agricultural industrial clusters in Hubei Province, including building agricultural industrial park and cultivating key leading enterprises, strengthening innovation management, and increasing financial support.
基金Project supported by the National Natural Science Foundation of China (Nos.12072119,12325201,and 52205594)the China National Postdoctoral Program for Innovative Talents (No.BX20220118)。
文摘Due to the novel applications of flexible pipes conveying fluid in the field of soft robotics and biomedicine,the investigations on the mechanical responses of the pipes have attracted considerable attention.The fluid-structure interaction(FSI)between the pipe with a curved shape and the time-varying internal fluid flow brings a great challenge to the revelation of the dynamical behaviors of flexible pipes,especially when the pipe is highly flexible and usually undergoes large deformations.In this work,the geometrically exact model(GEM)for a curved cantilevered pipe conveying pulsating fluid is developed based on the extended Hamilton's principle.The stability of the curved pipe with three different subtended angles is examined with the consideration of steady fluid flow.Specific attention is concentrated on the large-deformation resonance of circular pipes conveying pulsating fluid,which is often encountered in practical engineering.By constructing bifurcation diagrams,oscillating shapes,phase portraits,time traces,and Poincarémaps,the dynamic responses of the curved pipe under various system parameters are revealed.The mean flow velocity of the pulsating fluid is chosen to be either subcritical or supercritical.The numerical results show that the curved pipe conveying pulsating fluid can exhibit rich dynamical behaviors,including periodic and quasi-periodic motions.It is also found that the preferred instability type of a cantilevered curved pipe conveying steady fluid is mainly in the flutter of the second mode.For a moderate value of the mass ratio,however,a third-mode flutter may occur,which is quite different from that of a straight pipe system.
基金sponsored by the Specific Fund of Fundamental Research,Institute of Geophysics,China Earthquake Administration (DQJB16B19)
文摘This paper reviewed the main target,functions,tool( Open Quake software) and research achievements of the Global Earthquake Model( GEM) Foundation,and made a simple prospect on the development and application of projects of GEM in the future. Learning from GEM and Open Quake is helpful to improve the seismic hazard model of China and enhance the scientificity of the seismic hazard assessment for metropolitans and major engineering facilities near major seismogenic structures.
文摘分析了电阻率和电阻几何系数对基于炭黑/硅橡胶的力敏导电橡胶的"正拉力-电阻特性"(positivetensile coefficient of resistance,PTCR)的影响程度,揭示了力敏导电橡胶拉伸过程的电阻变化机理。在一定拉伸范围内(40%),当导电填料用量处在渗流区中心时,电阻率的增大是引起PTCR效应的主要原因。随着导电填料用量的增大,电阻几何系数的增大成为引起PTCR效应的主要原因。在某一特定导电填料范围内,力敏导电橡胶的"正拉力-电阻特性"还与拉伸长度有关。拉伸长度较小时,电阻几何系数的增大在PTCR效应中占主导;拉伸长度较大时,电阻率的增大在PTCR效应中占主导。
