Climatic characteristics of foreign low latitude plateau regions are firstly introduced.Then,experience and lessons of major foreign low latitude plateau countries in developing modern agriculture are analyzed,includi...Climatic characteristics of foreign low latitude plateau regions are firstly introduced.Then,experience and lessons of major foreign low latitude plateau countries in developing modern agriculture are analyzed,including Indian three agricultural revolutions and agricultural informationization development,application of agricultural biotechnology in Brazil,trade liberalization and economic de-agriculture of Mexico,and Argentina,Saudi Arabia and South Africa attaching great importance to developing modern agriculture relying on science and technology and paying close attention to resource conservation and environmental protection.Combining natural and social resource characteristics of Yunnan plateau agriculture,pertinent implications and recommendations for modern agricultural development in Yunnan are put forward.Specifically,these include strengthening agricultural sci-tech research and development,and extension and application;transforming agricultural development model;enhancing agricultural resource conservation and environmental protection;accelerating developing mountain organic ecological agriculture and autumn agriculture;reinforcing urban and rural integration to develop plateau characteristic agriculture on the basis of local actual conditions.展开更多
This paper firstly summarized experience of Vietnam and Taiwan in developing modern agricultural manorial economy. The manorial economy of Vietnam is characterized by intensive and specialized operation and high marke...This paper firstly summarized experience of Vietnam and Taiwan in developing modern agricultural manorial economy. The manorial economy of Vietnam is characterized by intensive and specialized operation and high marketization and wide employment of labors,while the experience of Taiwan can be outlined as " government launching,agricultural association promoting,and farmers acting". Then,it analyzed existing problems of modern agricultural manorial economy in China and opportunities and challenges of characteristic modern agricultural manorial economy in Yunnan plateau area. Finally in line with these problems and combining experience of international manorial economy,it came up with systematic recommendations for healthy and sustainable development of characteristic modern agricultural manorial economy in Yunnan plateau area:(i) perfecting organization leadership,improving planning guidance,and enhancing standardized management;(ii) putting forth effort on innovation of system and mechanism for land,fund and technology,to break bottleneck of manorial economic development;(iii) increasing input and comprehensively building the service support system to promote long-term development of manorial economy.展开更多
Yunnan plateau characteristic agriculture is an essential force for increasing farmers' income and promoting prosperity of rural economy. The fundamental position of agriculture should be kept all the time. This p...Yunnan plateau characteristic agriculture is an essential force for increasing farmers' income and promoting prosperity of rural economy. The fundamental position of agriculture should be kept all the time. This paper analyzed practical basis and existing problems in development of Yunnan plateau characteristic agriculture. In line with these problems,it present ideas,main points and objectives of Yunnan plateau characteristic agriculture,and finally came up with recommendations for accelerating development of Yunnan plateau characteristic agriculture.展开更多
Spark plasma sintering(SPS)is a highly efficient method for the preparation ofα/β-SiAlON ceramics.However,the rapid preparation of large-scaleα/β-SiAlON ceramic components with reliable mechanical properties is di...Spark plasma sintering(SPS)is a highly efficient method for the preparation ofα/β-SiAlON ceramics.However,the rapid preparation of large-scaleα/β-SiAlON ceramic components with reliable mechanical properties is difficult via SPS due to their near-insulating properties.In this study,high-performanceα/β-SiAlON ceramic end mill rods with large aspect ratios were successfully prepared via SPS.Two different types of sintering processes(namely vertical-round-rod(VRR)and horizontal-square-rod(HSR)processes)were developed,and their effects on the phase composition,microstructure,mechanical properties,and machining performance of theα/β-SiAlON ceramic end mill rods were studied.The electric and temperature field distributions during sintering were studied through an electro–thermal simulation.The simulated and experimental temperature distributions are in good agreement.In contrast to VRR samples,HSR samples with a small axial size show a uniform temperature distribution and satisfactory microstructures within a certain range of dimensions as well as the expected phase composition;furthermore,elongatedβ-SiAlON grains are preferentially oriented in the direction perpendicular to the sintering pressure direction.As a result,the HSR samples exhibit better mechanical properties and machining performance than the VRR samples.展开更多
Electromagnetic interference(EMI)shielding materials have received considerable attention in recent years.The EMI shielding effectiveness(SE)of materials depends on not only their composition but also their microstruc...Electromagnetic interference(EMI)shielding materials have received considerable attention in recent years.The EMI shielding effectiveness(SE)of materials depends on not only their composition but also their microstructures.Among various microstructure prototypes,porous structures provide the advantages of low density and high terahertz wave absorption.In this study,by using carbonised wood(CW)as a template,1-mm-thick MAX@CW composites(Ti2AlC@CW,V2A1C@CW,and Cr2AlC@CW)with a porous structure were fabricated through the molten salt method.The MAX@CW composites led to the formation of a conductive network and multilayer interface,which resulted in improved EMI SE.The average EMI SE values of the three MAX@CW composites were>45 dB in the frequency of 0.6-1.6 THz.Among the composites,V2A1C@CW exhibited the highest average EMI SE of 55 dB.展开更多
基金Supported by Key Decision Advisory Program of Yunnan Provincial Development and Reform Commission
文摘Climatic characteristics of foreign low latitude plateau regions are firstly introduced.Then,experience and lessons of major foreign low latitude plateau countries in developing modern agriculture are analyzed,including Indian three agricultural revolutions and agricultural informationization development,application of agricultural biotechnology in Brazil,trade liberalization and economic de-agriculture of Mexico,and Argentina,Saudi Arabia and South Africa attaching great importance to developing modern agriculture relying on science and technology and paying close attention to resource conservation and environmental protection.Combining natural and social resource characteristics of Yunnan plateau agriculture,pertinent implications and recommendations for modern agricultural development in Yunnan are put forward.Specifically,these include strengthening agricultural sci-tech research and development,and extension and application;transforming agricultural development model;enhancing agricultural resource conservation and environmental protection;accelerating developing mountain organic ecological agriculture and autumn agriculture;reinforcing urban and rural integration to develop plateau characteristic agriculture on the basis of local actual conditions.
基金Supported by Survey Program of Yunnan Provincial Committee of the Jiu San Society
文摘This paper firstly summarized experience of Vietnam and Taiwan in developing modern agricultural manorial economy. The manorial economy of Vietnam is characterized by intensive and specialized operation and high marketization and wide employment of labors,while the experience of Taiwan can be outlined as " government launching,agricultural association promoting,and farmers acting". Then,it analyzed existing problems of modern agricultural manorial economy in China and opportunities and challenges of characteristic modern agricultural manorial economy in Yunnan plateau area. Finally in line with these problems and combining experience of international manorial economy,it came up with systematic recommendations for healthy and sustainable development of characteristic modern agricultural manorial economy in Yunnan plateau area:(i) perfecting organization leadership,improving planning guidance,and enhancing standardized management;(ii) putting forth effort on innovation of system and mechanism for land,fund and technology,to break bottleneck of manorial economic development;(iii) increasing input and comprehensively building the service support system to promote long-term development of manorial economy.
基金Supported by Key Development and Research Project of Yunnan Provincial Development and Reform Commission(2012)
文摘Yunnan plateau characteristic agriculture is an essential force for increasing farmers' income and promoting prosperity of rural economy. The fundamental position of agriculture should be kept all the time. This paper analyzed practical basis and existing problems in development of Yunnan plateau characteristic agriculture. In line with these problems,it present ideas,main points and objectives of Yunnan plateau characteristic agriculture,and finally came up with recommendations for accelerating development of Yunnan plateau characteristic agriculture.
基金supported by the National Natural Science Foundation of China(Nos.52075266,51875291)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_0402).
文摘Spark plasma sintering(SPS)is a highly efficient method for the preparation ofα/β-SiAlON ceramics.However,the rapid preparation of large-scaleα/β-SiAlON ceramic components with reliable mechanical properties is difficult via SPS due to their near-insulating properties.In this study,high-performanceα/β-SiAlON ceramic end mill rods with large aspect ratios were successfully prepared via SPS.Two different types of sintering processes(namely vertical-round-rod(VRR)and horizontal-square-rod(HSR)processes)were developed,and their effects on the phase composition,microstructure,mechanical properties,and machining performance of theα/β-SiAlON ceramic end mill rods were studied.The electric and temperature field distributions during sintering were studied through an electro–thermal simulation.The simulated and experimental temperature distributions are in good agreement.In contrast to VRR samples,HSR samples with a small axial size show a uniform temperature distribution and satisfactory microstructures within a certain range of dimensions as well as the expected phase composition;furthermore,elongatedβ-SiAlON grains are preferentially oriented in the direction perpendicular to the sintering pressure direction.As a result,the HSR samples exhibit better mechanical properties and machining performance than the VRR samples.
基金supported financially by the National Natural Science Foundation of China(Grant Nos.51902320,61831012,and U2004212)Qing Huang thanks International Partnership Program of Chinese Academy of Sciences(Grant No.174433KYSB20190019)+1 种基金the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(Grant No.2019R01003)Mian Li acknowledges the support from the fund of the State Key Laboratory of Solidification Processing in NPU(Grant No.SKLSP201917).
文摘Electromagnetic interference(EMI)shielding materials have received considerable attention in recent years.The EMI shielding effectiveness(SE)of materials depends on not only their composition but also their microstructures.Among various microstructure prototypes,porous structures provide the advantages of low density and high terahertz wave absorption.In this study,by using carbonised wood(CW)as a template,1-mm-thick MAX@CW composites(Ti2AlC@CW,V2A1C@CW,and Cr2AlC@CW)with a porous structure were fabricated through the molten salt method.The MAX@CW composites led to the formation of a conductive network and multilayer interface,which resulted in improved EMI SE.The average EMI SE values of the three MAX@CW composites were>45 dB in the frequency of 0.6-1.6 THz.Among the composites,V2A1C@CW exhibited the highest average EMI SE of 55 dB.
