The space-air-ground integrated network(SAGIN) is regarded as the key approach to realize global coverage in future network and it reaches broad access for various services. Being the new paradigm of service, immersiv...The space-air-ground integrated network(SAGIN) is regarded as the key approach to realize global coverage in future network and it reaches broad access for various services. Being the new paradigm of service, immersive media(IM) has attracted users’ attention for its virtualization, but it poses challenges to network performance, e.g. bandwidth, rate, latency. However, the SAGIN has limitations in supporting IM services, such as 4 K/8 K video, virtual reality, and interactive games. In this paper, a novel service customized SAGIN architecture for IM applications(SAG-IM) is proposed, which achieves content interactive and real-time communication among terminal users. State-of-the-art research is investigated in detail to facilitate the combination of SAGIN and service customized technology, which provides endto-end differentiated services for users. Besides, the functional components of SAG-IM contain the infrastructure layer, perception layer, intelligence layer, and application layer, reaching the capabilities of intelligent management of the network. Moreover, to provide IM content with ultra-high-definition and high frame rate for the optimal user experience, the promising key technologies on intelligent routing and delivery are discussed. The performance evaluation shows the superiority of SAG-IM in supporting IM service.Finally, the prospects in practical application are high-lighted.展开更多
In order to improve the enhanced oil recovery of high-temperature and high-salt oilfields, a novel temperature-resistant and salt-tolerant surfactant (denoted as SDB-7) was synthesized and evaluated for the Tahe Oil...In order to improve the enhanced oil recovery of high-temperature and high-salt oilfields, a novel temperature-resistant and salt-tolerant surfactant (denoted as SDB-7) was synthesized and evaluated for the Tahe Oilfield (Xinjiang, China), which is representative of high-temperature and high-salt oilfields. It has a central reservoir temperature of 140 ℃ and salinity of 22.6× 10^4 mg/L. The temperature-resistant and salt-tolerant performance, interfacial activity, oil displacement efficiency, aging properties, and adsorption properties of the synthesized surfactant were evaluated for Tahe Oilfield flooding. The results showed that the SDB-7 was temperature-resistant and salt-tolerant capacity of 140 ℃ and 22.6×10^4 rag/ L, respectively, oil displacement efficiency under static condition of 84%, and adsorption loss of 0.4 mg/ g (less than 1 mg/g-oil sand). In the heat aging experiment (under the temperature of 140 ℃ for 60 days), the oil-water interracial tension and oil displacement efficiency of SDB-7 were almost unchanged. The oil displacement experiments showed that, under the temperature of 140 ℃ and the salinity of 22.6× 10^4 mg/L, the surfactant SDB-7 can enhance oil recovery by 14.5% after water flooding,suggesting that SDB-7 has a promising application in high temperature and high salinity (HT/HS) reservoir.展开更多
Because of cloudy and rainy weather in south China, optical remote sens-ing images often can't be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model an...Because of cloudy and rainy weather in south China, optical remote sens-ing images often can't be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model and effect of ENVISAT/SAR and HJ-1A satel ite multispectral remote sensing images. Based on the ARSIS strat-egy, using the wavelet transform and the Interaction between the Band Structure Model (IBSM), the research progressed the ENVISAT satel ite SAR and the HJ-1A satel ite CCD images wavelet decomposition, and low/high frequency coefficient re-construction, and obtained the fusion images through the inverse wavelet transform. In the light of low and high-frequency images have different characteristics in differ-ent areas, different fusion rules which can enhance the integration process of self-adaptive were taken, with comparisons with the PCA transformation, IHS transfor-mation and other traditional methods by subjective and the corresponding quantita-tive evaluation. Furthermore, the research extracted the bands and NDVI values around the fusion with GPS samples, analyzed and explained the fusion effect. The results showed that the spectral distortion of wavelet fusion, IHS transform, PCA transform images was 0.101 6, 0.326 1 and 1.277 2, respectively and entropy was 14.701 5, 11.899 3 and 13.229 3, respectively, the wavelet fusion is the highest. The method of wavelet maintained good spectral capability, and visual effects while improved the spatial resolution, the information interpretation effect was much better than other two methods.展开更多
The sandwich transducer structure is comprised of threecomponents along its main axis: the back metal cap, piezoelectricceramic stack and the horn. The purpose of this work is topresent a simplified method, referred a...The sandwich transducer structure is comprised of threecomponents along its main axis: the back metal cap, piezoelectricceramic stack and the horn. The purpose of this work is topresent a simplified method, referred as the equivalent lengthalgorithm, to design the actuator parameters including eachsegment length and the resonance frequency fs. The actuatorlength L and the propagation wavelength λ along its main axissatisfy the standing wave theory. So, define an equivalent lengthcoefficient for each part of the actuator, and then the sandwichstructure is regarded as a single material cylindrical rod withequivalent length L′. According to the standing wave theory, theequivalent length L′ of the actuator can be determined with thegiven resonance frequency fs, or vice versa. The phase length ofeach part of the actuator in the standing wave is optimized freelyin the design procedure. The actual length of each part of theactuator is determined by the equivalent length coefficient.Finally, the resonance frequencies of three given actuators arecalculated with this method. They are compared with thoseobtained through Ansys simulation and those measured by animpedance analyzer. The results show agreement.展开更多
We select the per capita gross domestic product and rural residents' per capita net income in Xinjiang as the indicator variables to measure economic growth and farmers' income increase in Xinjiang, respective...We select the per capita gross domestic product and rural residents' per capita net income in Xinjiang as the indicator variables to measure economic growth and farmers' income increase in Xinjiang, respectively. We establish the cointegration equation, the vector error correction (VEC) model, and use the impulse response function to conduct empirical analysis of the evolutive law concerning relationship between economic growth and farmers' income increase in Xinjiang during the period 1978-2010. The results show that there is a cointegration relationship between economic growth in Xinjiang and farmers' income increase; the former plays an important role in promoting the latter, following the evolutive law "first intensify, then abate, intensify again, and finally become stable". We put the following policy recommendations: providing preferential policies for farmers, scientifically and rationally guiding the transfer of rural labor; improving the function of agriculture, increasing the proportion of non-farm income; gradually bridging the widening income gap between urban and rural areas, coordinating urban and rural development.展开更多
As a southwestern border province of China,Yunnan is featured by the geographical advantage of proximity to the Indo-China Peninsula which is known as World Rice Warehouse,and its capital and technology are ahead of t...As a southwestern border province of China,Yunnan is featured by the geographical advantage of proximity to the Indo-China Peninsula which is known as World Rice Warehouse,and its capital and technology are ahead of the neighboring countries of China.Therefore,to enhance its support capability in consolidating and improving the national food security strategy,Yunnan should further develop its comparative advantages by building the regional food industry chain and supply chain depending on the province's grain system of production,processing,storage and transportation,as well as its agricultural economic and trade cooperation platforms and channels with the neighboring countries of China.In this study,comparative analysis and related methods were used to systematically analyze the scale of grain production in Yunnan,the proportion of its grain production to the national total amount,the transition of its grain variety structure and the characteristics of its food security system,as well as the grain export trade of the 6 countries in the Indo-China Peninsula from 2010 to 2019.Then,the problems in grain production in Yunnan were clarified,such as the decrease of grain ration production capacity,the decline of comparative benefits of grain production and the insufficient support for agricultural"going global"strategy.Finally,a series of countermeasures were put forward,including further implementing the strategy of"reserving grain in land and technology"to increase Yunnan's production capacity of grain,focusing on agricultural products storage and transportation system to improve the ability to obtain grain from abroad,expanding the border processing and logistics industry,optimizing the policy of agricultural products'import and export,and etc.展开更多
On basis of an analysis of the geological condition, law of gas outburst and materials about coal-and-gas outburst, this paper summarized the characteristics associated with coal-and-gas outburst of Zhaogezhuang Mine ...On basis of an analysis of the geological condition, law of gas outburst and materials about coal-and-gas outburst, this paper summarized the characteristics associated with coal-and-gas outburst of Zhaogezhuang Mine and studied the factors controlling coal-and-gas outburst such as stress, coal structure and gas pressure, content of gas. Then, based on a comparison of effects of in-situ stresses, coal structure and gas on coal-and-gas outburst of Zhaogezhuang Mine, the paper concludes that the major geological factors that control coal-and-gas outburst of Zhaogezhuang Mine are in-situ stresses and coal structure.展开更多
In order to quantitatively analyze grassland resources policies of Ningxia,the analytic hierarchy process(AHP)was used to establish the evaluation index system,and the fuzzy comprehensive evaluation method was adopted...In order to quantitatively analyze grassland resources policies of Ningxia,the analytic hierarchy process(AHP)was used to establish the evaluation index system,and the fuzzy comprehensive evaluation method was adopted to make a comprehensive evaluation.The results indicated that the current grassland resources policies in Ningxia are in upper-middle level,and the relevant policies need to be improved.Finally,the corresponding suggestions were put forward in the hope of promoting the sustainable development of grassland resources in Ningxia.展开更多
As illustrated by the case of Xuyi County, Jinhu County and Hongze County in Jiangsu Province, China, monitoring and forecasting of rice production were carried out by using HJ-1A satellite remote sensing images. The ...As illustrated by the case of Xuyi County, Jinhu County and Hongze County in Jiangsu Province, China, monitoring and forecasting of rice production were carried out by using HJ-1A satellite remote sensing images. The handhold GPS machines were used to measure the geographical position and some other information of these samples such as area shape. The GPS data and the interpretation marks were used to correct H J-1 image, assist human-computer interactive interpretation, and other operations. The test data had been participated in the whole classification process. The accuracy of interpreted information on rice planting area was more than 90% By using the leaf area index from the normalized difference vegetation index inversion, the biomass from the ratio vegetation index inversion, and combined with the rice yield estimation model, the rice yield was estimated. Further, the thematic map of rice production classification was made based on the rice yield data. According to the comparison results between measured and fitted values of yields and areas of sampling sites, the accuracy of the yield estimation was more than 85%. The results suggest that HJ-A/B images could basically meet the demand of rice growth monitoring and yield forecasting, and could be widely applied to rice production monitoring.展开更多
[Objective]The paper was to clarify the application of biochemical fulvic acid potassium on the survival rate and growth of various trees transplanted in the process of landscaping.[Method]Two experimental treatments(...[Objective]The paper was to clarify the application of biochemical fulvic acid potassium on the survival rate and growth of various trees transplanted in the process of landscaping.[Method]Two experimental treatments(i.e.decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,decomposed organic fertilizer+compound fertilizer)were designed to determine the changes in physical and chemical properties before and after soil treatment,and the survival rate,plant height and ground diameter of four different cultivated plants within one year,and the effects of applying biochemical fulvic acid potassium on cultivated plants were investigated.[Result]The soil organic matter,total nitrogen,alkali-hydrolyzable nitrogen,soil available phosphorus,soil available potassium and p H value in the soil treated with decomposed organic fertilizer+biochemical fulvic acid potassium soluble fertilizer,and decomposed organic fertilizer+compound fertilizer increased significantly,and the soil bulk density decreased obviously.The survival rates,plant heights and ground diameters of four different cultivated plants were significantly improved after application of decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,and decomposed organic fer-tilizer+compound fertilizer(P<0.05).[Conclusion]The application of biochemical fulvic acid potassium on cultivated plants effectively improved soil fertility,increased the utilization of nitrogen,phosphorus and potassium,improved the growth of plants,and promoted the growth of landscaping plants after transplantation.展开更多
Many coal enterprises have built the videoconference systems on their LAN (Local Area Network). As the development of these enterprises, their organizations are distributed over our country and even over the world. ...Many coal enterprises have built the videoconference systems on their LAN (Local Area Network). As the development of these enterprises, their organizations are distributed over our country and even over the world. Therefore, the videoconference systems have to run over WAN (Wide Area Network). Normally, the structure of a videoconference system is center_division including MCU (multi control unit)and participants. No QoS and security assurance are available now because all videoconference system is based on TCP/IP. Therefore, the system stability is absolutely depended on the Network. This paper discussed how to anti ARP attacking. The method discussed in this paper is based on TCP/IP.展开更多
MODTRAN model was used for the atmospheric correction of one HJ-1B / CCD2 image,and the effect of atmospheric correction was evaluated from the changes of spectral characteristics of typical ground objects,the compari...MODTRAN model was used for the atmospheric correction of one HJ-1B / CCD2 image,and the effect of atmospheric correction was evaluated from the changes of spectral characteristics of typical ground objects,the comparison with the MODIS surface reflectance product,and the effect on normalized differential vegetation index( NDVI). The results show that atmospheric correction eliminated the increase effect in visible bands and the absorption in near-infrared band. Atmospheric correction results and the MODIS surface reflectance product with high accuracy were highly consistent in the reflectance of vegetation,water and residents,and the average error of vegetation was 12.8%. According to the comparison of changing characteristics of NDVI before and after atmospheric correction,it could be found that atmospheric correction had corrected NDVI of mixed pixels and made it more reasonable. NDVI of each kind of ground objects improved,among which NDVI of vegetation increased most greatly,which can help differentiate vegetation from other ground objects. In a word,MODTRAN model has a good effect on atmospheric correction of HJ /CCD images.展开更多
With the case study of two rural communities of Hetian County and Shawan County in Xinjiang, the foundation, operation and development of the water management organizations in the two communities and their reform achi...With the case study of two rural communities of Hetian County and Shawan County in Xinjiang, the foundation, operation and development of the water management organizations in the two communities and their reform achievements were studied and compared. It was concluded that the reform of water resources management should be in accordance with the practical conditions of rural communities. Only with the same objectives of community people and by benefiting the farmers could the reform of water resources management be effectively implemented and achieve good results.展开更多
As a high-quality milk source base in China,Xinjiang has an innate foundation for the development of modern high-quality milk industry.In this paper,it was pointed out that the uneven distribution of interests between...As a high-quality milk source base in China,Xinjiang has an innate foundation for the development of modern high-quality milk industry.In this paper,it was pointed out that the uneven distribution of interests between the upstream and downstream of the industry was the influencing factor restricting the development of modern dairy industry in Xinjiang.At the same time,the related information of Tianrun Group,which was the leading enterprise in Xinjiang,was analyzed.According to analysis,it was found that through the construction and development of large-scale,standardized and modern milk source base,balance of the upstream and downstream interests,improvement of the combination system of planting and breeding,the added value of products was enhanced and the anti risk ability of enterprises was increased.In addition,it was also pointed out that under the leadership of leading enterprises,Xinjiang would embark on the development road of modern high-quality milk industry with circular economy,resource-saving,environment-friendly,quality and efficiency,operation-saving,independent innovation and industrial integration in the future.展开更多
The energy consumption in large-scale data centers is attracting more and more attention today with the increasing data center energy costs making the enhanced performance very expensive. This is becoming a bottleneck...The energy consumption in large-scale data centers is attracting more and more attention today with the increasing data center energy costs making the enhanced performance very expensive. This is becoming a bottleneck to further developments in terms of both scale and performance of cloud computing. Thus, the reduction of the energy consumption by data centers is becoming a key research topic in green IT and green computing. The web servers providing cloud service computing run at various speeds for different scenarios. By shifting among these states using speed scaling, the energy consumption is proportional to the workload, which is termed energy-proportionality. This study uses stochastic service decision nets to investigate energy-efficient speed scaling on web servers. This model combines stochastic Petri nets with Markov decision process models. This enables the model to dynamically optimize the speed scaling strategy and make performance evaluations. The model is graphical and intuitive enough to characterize complicated system behavior and decisions. The model is service-oriented using the typical service patterns to reduce the complex model to a simple model with a smaller state space. Performance and reward equivalent analyse substantially reduces the system behavior sub-net. The model gives the optimal strategy and evaluates performance and energy metrics more concisely.展开更多
Various diseases seriously affect the quality and yield of tomatoes. Fast and accurate identification of disease types is of great significance for the development of smart agriculture. Many Convolution Neural Network...Various diseases seriously affect the quality and yield of tomatoes. Fast and accurate identification of disease types is of great significance for the development of smart agriculture. Many Convolution Neural Network (CNN) models have been applied to the identification of tomato leaf diseases and achieved good results. However, some of these are executed at the cost of large calculation time and huge storage space. This study proposed a lightweight CNN model named MFRCNN, which is established by the multi-scale and feature reuse structure rather than simply stacking convolution layer by layer. To examine the model performances, two types of tomato leaf disease datasets were collected. One is the laboratory-based dataset, including one healthy and nine diseases, and the other is the field-based dataset, including five kinds of diseases. Afterward, the proposed MFRCNN and some popular CNN models (AlexNet, SqueezeNet, VGG16, ResNet18, and GoogLeNet) were tested on the two datasets. The results showed that compared to traditional models, the MFRCNN achieved the optimal performance, with an accuracy of 99.01% and 98.75% in laboratory and field datasets, respectively. The MFRCNN not only had the highest accuracy but also had relatively less computing time and few training parameters. Especially in terms of storage space, the MFRCNN model only needs 2.7 MB of space. Therefore, this work provides a novel solution for plant disease diagnosis, which is of great importance for the development of plant disease diagnosis systems on low-performance terminals.展开更多
The development status of rural informatization in Beijing was analyzed from three aspects,which include infrastructure building,resource platform and service system construction,and the information technology applica...The development status of rural informatization in Beijing was analyzed from three aspects,which include infrastructure building,resource platform and service system construction,and the information technology application in rural areas.The infrastructure building in Beijing had certain scale,and the network coverage in rural counties and the rate of network into villages almost reached 100%.The construction of resource platform and service systems was diversified and it provided various types of services for farmers’lives.However,the information platforms and sites were dispersive and needed to be integrated and shared.The typical'211 information platform is one system platform which integrated source and market the two things,which means the first‘2’.It used fund which means the‘1’,and technology which means the other‘1’as support,and government departments and all kinds of producers could do some information activities through this platform.It had strong inquiry,analysis and synthesis functions for decision-making services through integrated and shared municipal organizations and counties'agricultural resources.On the aspect of information technology application,informatization has enhanced the technology level of Beijing urban modern agriculture and sustainable development capacity.The application of public service,e-government and e-commerce facilitated farmers’lives,improved the development of government management and rural economy.In the future,the rural informatization still needs to strengthen the integration and sharing of agriculture-related resources,reduce the public service informatization gap between rural and urban areas,and improve farmers'informatization awareness.展开更多
基金supported by the National Key Research and Development Program of China (No.2019YFB1803103)in part by the BUPT Excellent Ph.D. Students Foundation (No.CX2021113)。
文摘The space-air-ground integrated network(SAGIN) is regarded as the key approach to realize global coverage in future network and it reaches broad access for various services. Being the new paradigm of service, immersive media(IM) has attracted users’ attention for its virtualization, but it poses challenges to network performance, e.g. bandwidth, rate, latency. However, the SAGIN has limitations in supporting IM services, such as 4 K/8 K video, virtual reality, and interactive games. In this paper, a novel service customized SAGIN architecture for IM applications(SAG-IM) is proposed, which achieves content interactive and real-time communication among terminal users. State-of-the-art research is investigated in detail to facilitate the combination of SAGIN and service customized technology, which provides endto-end differentiated services for users. Besides, the functional components of SAG-IM contain the infrastructure layer, perception layer, intelligence layer, and application layer, reaching the capabilities of intelligent management of the network. Moreover, to provide IM content with ultra-high-definition and high frame rate for the optimal user experience, the promising key technologies on intelligent routing and delivery are discussed. The performance evaluation shows the superiority of SAG-IM in supporting IM service.Finally, the prospects in practical application are high-lighted.
基金the China National High Technology Research and Development Program (No. 2013AA064301)National Natural Science Foundation of China (No. 51274210) for financial support
文摘In order to improve the enhanced oil recovery of high-temperature and high-salt oilfields, a novel temperature-resistant and salt-tolerant surfactant (denoted as SDB-7) was synthesized and evaluated for the Tahe Oilfield (Xinjiang, China), which is representative of high-temperature and high-salt oilfields. It has a central reservoir temperature of 140 ℃ and salinity of 22.6× 10^4 mg/L. The temperature-resistant and salt-tolerant performance, interfacial activity, oil displacement efficiency, aging properties, and adsorption properties of the synthesized surfactant were evaluated for Tahe Oilfield flooding. The results showed that the SDB-7 was temperature-resistant and salt-tolerant capacity of 140 ℃ and 22.6×10^4 rag/ L, respectively, oil displacement efficiency under static condition of 84%, and adsorption loss of 0.4 mg/ g (less than 1 mg/g-oil sand). In the heat aging experiment (under the temperature of 140 ℃ for 60 days), the oil-water interracial tension and oil displacement efficiency of SDB-7 were almost unchanged. The oil displacement experiments showed that, under the temperature of 140 ℃ and the salinity of 22.6× 10^4 mg/L, the surfactant SDB-7 can enhance oil recovery by 14.5% after water flooding,suggesting that SDB-7 has a promising application in high temperature and high salinity (HT/HS) reservoir.
基金supported by the National Natural Science Foundation of China(41171336)the Project of Jiangsu Province Agricultural Science and Technology Innovation Fund(CX12-3054)
文摘Because of cloudy and rainy weather in south China, optical remote sens-ing images often can't be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model and effect of ENVISAT/SAR and HJ-1A satel ite multispectral remote sensing images. Based on the ARSIS strat-egy, using the wavelet transform and the Interaction between the Band Structure Model (IBSM), the research progressed the ENVISAT satel ite SAR and the HJ-1A satel ite CCD images wavelet decomposition, and low/high frequency coefficient re-construction, and obtained the fusion images through the inverse wavelet transform. In the light of low and high-frequency images have different characteristics in differ-ent areas, different fusion rules which can enhance the integration process of self-adaptive were taken, with comparisons with the PCA transformation, IHS transfor-mation and other traditional methods by subjective and the corresponding quantita-tive evaluation. Furthermore, the research extracted the bands and NDVI values around the fusion with GPS samples, analyzed and explained the fusion effect. The results showed that the spectral distortion of wavelet fusion, IHS transform, PCA transform images was 0.101 6, 0.326 1 and 1.277 2, respectively and entropy was 14.701 5, 11.899 3 and 13.229 3, respectively, the wavelet fusion is the highest. The method of wavelet maintained good spectral capability, and visual effects while improved the spatial resolution, the information interpretation effect was much better than other two methods.
基金supported by National NaturalScience Foundation of China [grant numbers 51475031 and51475029].
文摘The sandwich transducer structure is comprised of threecomponents along its main axis: the back metal cap, piezoelectricceramic stack and the horn. The purpose of this work is topresent a simplified method, referred as the equivalent lengthalgorithm, to design the actuator parameters including eachsegment length and the resonance frequency fs. The actuatorlength L and the propagation wavelength λ along its main axissatisfy the standing wave theory. So, define an equivalent lengthcoefficient for each part of the actuator, and then the sandwichstructure is regarded as a single material cylindrical rod withequivalent length L′. According to the standing wave theory, theequivalent length L′ of the actuator can be determined with thegiven resonance frequency fs, or vice versa. The phase length ofeach part of the actuator in the standing wave is optimized freelyin the design procedure. The actual length of each part of theactuator is determined by the equivalent length coefficient.Finally, the resonance frequencies of three given actuators arecalculated with this method. They are compared with thoseobtained through Ansys simulation and those measured by animpedance analyzer. The results show agreement.
基金Supported by Soft Science Project of Science and Technology Department of Xinjiang Uygur Autonomous Region (200942140)
文摘We select the per capita gross domestic product and rural residents' per capita net income in Xinjiang as the indicator variables to measure economic growth and farmers' income increase in Xinjiang, respectively. We establish the cointegration equation, the vector error correction (VEC) model, and use the impulse response function to conduct empirical analysis of the evolutive law concerning relationship between economic growth and farmers' income increase in Xinjiang during the period 1978-2010. The results show that there is a cointegration relationship between economic growth in Xinjiang and farmers' income increase; the former plays an important role in promoting the latter, following the evolutive law "first intensify, then abate, intensify again, and finally become stable". We put the following policy recommendations: providing preferential policies for farmers, scientifically and rationally guiding the transfer of rural labor; improving the function of agriculture, increasing the proportion of non-farm income; gradually bridging the widening income gap between urban and rural areas, coordinating urban and rural development.
基金Supported by the Construction of Think Tank for Yunnan Agricultural Development and Policy Research on Science and Technology Management(202102AE090036-15)the Research Project of Yunnan Provincial Committee of Jiusan Society(YN93/2020018)the Talent Project for Yunling Scholars(YNWR-YLXZ-2019-013)。
文摘As a southwestern border province of China,Yunnan is featured by the geographical advantage of proximity to the Indo-China Peninsula which is known as World Rice Warehouse,and its capital and technology are ahead of the neighboring countries of China.Therefore,to enhance its support capability in consolidating and improving the national food security strategy,Yunnan should further develop its comparative advantages by building the regional food industry chain and supply chain depending on the province's grain system of production,processing,storage and transportation,as well as its agricultural economic and trade cooperation platforms and channels with the neighboring countries of China.In this study,comparative analysis and related methods were used to systematically analyze the scale of grain production in Yunnan,the proportion of its grain production to the national total amount,the transition of its grain variety structure and the characteristics of its food security system,as well as the grain export trade of the 6 countries in the Indo-China Peninsula from 2010 to 2019.Then,the problems in grain production in Yunnan were clarified,such as the decrease of grain ration production capacity,the decline of comparative benefits of grain production and the insufficient support for agricultural"going global"strategy.Finally,a series of countermeasures were put forward,including further implementing the strategy of"reserving grain in land and technology"to increase Yunnan's production capacity of grain,focusing on agricultural products storage and transportation system to improve the ability to obtain grain from abroad,expanding the border processing and logistics industry,optimizing the policy of agricultural products'import and export,and etc.
基金Supported by the National Natural Science Foundation of China(40472084)
文摘On basis of an analysis of the geological condition, law of gas outburst and materials about coal-and-gas outburst, this paper summarized the characteristics associated with coal-and-gas outburst of Zhaogezhuang Mine and studied the factors controlling coal-and-gas outburst such as stress, coal structure and gas pressure, content of gas. Then, based on a comparison of effects of in-situ stresses, coal structure and gas on coal-and-gas outburst of Zhaogezhuang Mine, the paper concludes that the major geological factors that control coal-and-gas outburst of Zhaogezhuang Mine are in-situ stresses and coal structure.
基金This research is supported by Integration Technology Innovation Demonstration Project of Primary,Secondary and Tertiary Industries of Ningxia Academy of Agriculture and Forestry Sciences(Grant No.YES-16-10).
文摘In order to quantitatively analyze grassland resources policies of Ningxia,the analytic hierarchy process(AHP)was used to establish the evaluation index system,and the fuzzy comprehensive evaluation method was adopted to make a comprehensive evaluation.The results indicated that the current grassland resources policies in Ningxia are in upper-middle level,and the relevant policies need to be improved.Finally,the corresponding suggestions were put forward in the hope of promoting the sustainable development of grassland resources in Ningxia.
文摘As illustrated by the case of Xuyi County, Jinhu County and Hongze County in Jiangsu Province, China, monitoring and forecasting of rice production were carried out by using HJ-1A satellite remote sensing images. The handhold GPS machines were used to measure the geographical position and some other information of these samples such as area shape. The GPS data and the interpretation marks were used to correct H J-1 image, assist human-computer interactive interpretation, and other operations. The test data had been participated in the whole classification process. The accuracy of interpreted information on rice planting area was more than 90% By using the leaf area index from the normalized difference vegetation index inversion, the biomass from the ratio vegetation index inversion, and combined with the rice yield estimation model, the rice yield was estimated. Further, the thematic map of rice production classification was made based on the rice yield data. According to the comparison results between measured and fitted values of yields and areas of sampling sites, the accuracy of the yield estimation was more than 85%. The results suggest that HJ-A/B images could basically meet the demand of rice growth monitoring and yield forecasting, and could be widely applied to rice production monitoring.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201503119-03-02)。
文摘[Objective]The paper was to clarify the application of biochemical fulvic acid potassium on the survival rate and growth of various trees transplanted in the process of landscaping.[Method]Two experimental treatments(i.e.decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,decomposed organic fertilizer+compound fertilizer)were designed to determine the changes in physical and chemical properties before and after soil treatment,and the survival rate,plant height and ground diameter of four different cultivated plants within one year,and the effects of applying biochemical fulvic acid potassium on cultivated plants were investigated.[Result]The soil organic matter,total nitrogen,alkali-hydrolyzable nitrogen,soil available phosphorus,soil available potassium and p H value in the soil treated with decomposed organic fertilizer+biochemical fulvic acid potassium soluble fertilizer,and decomposed organic fertilizer+compound fertilizer increased significantly,and the soil bulk density decreased obviously.The survival rates,plant heights and ground diameters of four different cultivated plants were significantly improved after application of decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,and decomposed organic fer-tilizer+compound fertilizer(P<0.05).[Conclusion]The application of biochemical fulvic acid potassium on cultivated plants effectively improved soil fertility,increased the utilization of nitrogen,phosphorus and potassium,improved the growth of plants,and promoted the growth of landscaping plants after transplantation.
文摘Many coal enterprises have built the videoconference systems on their LAN (Local Area Network). As the development of these enterprises, their organizations are distributed over our country and even over the world. Therefore, the videoconference systems have to run over WAN (Wide Area Network). Normally, the structure of a videoconference system is center_division including MCU (multi control unit)and participants. No QoS and security assurance are available now because all videoconference system is based on TCP/IP. Therefore, the system stability is absolutely depended on the Network. This paper discussed how to anti ARP attacking. The method discussed in this paper is based on TCP/IP.
基金Supported by National Natural Science Foundation of China(41171336)
文摘MODTRAN model was used for the atmospheric correction of one HJ-1B / CCD2 image,and the effect of atmospheric correction was evaluated from the changes of spectral characteristics of typical ground objects,the comparison with the MODIS surface reflectance product,and the effect on normalized differential vegetation index( NDVI). The results show that atmospheric correction eliminated the increase effect in visible bands and the absorption in near-infrared band. Atmospheric correction results and the MODIS surface reflectance product with high accuracy were highly consistent in the reflectance of vegetation,water and residents,and the average error of vegetation was 12.8%. According to the comparison of changing characteristics of NDVI before and after atmospheric correction,it could be found that atmospheric correction had corrected NDVI of mixed pixels and made it more reasonable. NDVI of each kind of ground objects improved,among which NDVI of vegetation increased most greatly,which can help differentiate vegetation from other ground objects. In a word,MODTRAN model has a good effect on atmospheric correction of HJ /CCD images.
基金Supported by the International Cooperation Department of the Ministry of Science&Technology of the People's Republic of China(2010DFB90240)
文摘With the case study of two rural communities of Hetian County and Shawan County in Xinjiang, the foundation, operation and development of the water management organizations in the two communities and their reform achievements were studied and compared. It was concluded that the reform of water resources management should be in accordance with the practical conditions of rural communities. Only with the same objectives of community people and by benefiting the farmers could the reform of water resources management be effectively implemented and achieve good results.
基金Major Science and Technology Projects of Xinjiang Uygur Autonomous Region(2020A01001-4-3-2).
文摘As a high-quality milk source base in China,Xinjiang has an innate foundation for the development of modern high-quality milk industry.In this paper,it was pointed out that the uneven distribution of interests between the upstream and downstream of the industry was the influencing factor restricting the development of modern dairy industry in Xinjiang.At the same time,the related information of Tianrun Group,which was the leading enterprise in Xinjiang,was analyzed.According to analysis,it was found that through the construction and development of large-scale,standardized and modern milk source base,balance of the upstream and downstream interests,improvement of the combination system of planting and breeding,the added value of products was enhanced and the anti risk ability of enterprises was increased.In addition,it was also pointed out that under the leadership of leading enterprises,Xinjiang would embark on the development road of modern high-quality milk industry with circular economy,resource-saving,environment-friendly,quality and efficiency,operation-saving,independent innovation and industrial integration in the future.
基金supported by the National Key Basic Research and Development (973) Program (Nos. 2012CB315801, 2011CB302805, 2010CB328105,and 2009CB320504)the National Natural Science Foundation of China (Nos. 60932003, 61020106002, and 61161140320)the Intel Research Council with the title of "Security Vulnerability Analysis based on Cloud Platform with Intel IA Architecture"
文摘The energy consumption in large-scale data centers is attracting more and more attention today with the increasing data center energy costs making the enhanced performance very expensive. This is becoming a bottleneck to further developments in terms of both scale and performance of cloud computing. Thus, the reduction of the energy consumption by data centers is becoming a key research topic in green IT and green computing. The web servers providing cloud service computing run at various speeds for different scenarios. By shifting among these states using speed scaling, the energy consumption is proportional to the workload, which is termed energy-proportionality. This study uses stochastic service decision nets to investigate energy-efficient speed scaling on web servers. This model combines stochastic Petri nets with Markov decision process models. This enables the model to dynamically optimize the speed scaling strategy and make performance evaluations. The model is graphical and intuitive enough to characterize complicated system behavior and decisions. The model is service-oriented using the typical service patterns to reduce the complex model to a simple model with a smaller state space. Performance and reward equivalent analyse substantially reduces the system behavior sub-net. The model gives the optimal strategy and evaluates performance and energy metrics more concisely.
基金supported by the China Agriculture Research System (CARS-170404)Qingyuan Science and Technology Plan (Grant No.2022KJJH063)Guangzhou Science and Technology Plan (Grant No.201903010063).
文摘Various diseases seriously affect the quality and yield of tomatoes. Fast and accurate identification of disease types is of great significance for the development of smart agriculture. Many Convolution Neural Network (CNN) models have been applied to the identification of tomato leaf diseases and achieved good results. However, some of these are executed at the cost of large calculation time and huge storage space. This study proposed a lightweight CNN model named MFRCNN, which is established by the multi-scale and feature reuse structure rather than simply stacking convolution layer by layer. To examine the model performances, two types of tomato leaf disease datasets were collected. One is the laboratory-based dataset, including one healthy and nine diseases, and the other is the field-based dataset, including five kinds of diseases. Afterward, the proposed MFRCNN and some popular CNN models (AlexNet, SqueezeNet, VGG16, ResNet18, and GoogLeNet) were tested on the two datasets. The results showed that compared to traditional models, the MFRCNN achieved the optimal performance, with an accuracy of 99.01% and 98.75% in laboratory and field datasets, respectively. The MFRCNN not only had the highest accuracy but also had relatively less computing time and few training parameters. Especially in terms of storage space, the MFRCNN model only needs 2.7 MB of space. Therefore, this work provides a novel solution for plant disease diagnosis, which is of great importance for the development of plant disease diagnosis systems on low-performance terminals.
文摘The development status of rural informatization in Beijing was analyzed from three aspects,which include infrastructure building,resource platform and service system construction,and the information technology application in rural areas.The infrastructure building in Beijing had certain scale,and the network coverage in rural counties and the rate of network into villages almost reached 100%.The construction of resource platform and service systems was diversified and it provided various types of services for farmers’lives.However,the information platforms and sites were dispersive and needed to be integrated and shared.The typical'211 information platform is one system platform which integrated source and market the two things,which means the first‘2’.It used fund which means the‘1’,and technology which means the other‘1’as support,and government departments and all kinds of producers could do some information activities through this platform.It had strong inquiry,analysis and synthesis functions for decision-making services through integrated and shared municipal organizations and counties'agricultural resources.On the aspect of information technology application,informatization has enhanced the technology level of Beijing urban modern agriculture and sustainable development capacity.The application of public service,e-government and e-commerce facilitated farmers’lives,improved the development of government management and rural economy.In the future,the rural informatization still needs to strengthen the integration and sharing of agriculture-related resources,reduce the public service informatization gap between rural and urban areas,and improve farmers'informatization awareness.