A useful mid course guidance law for long range multi purpose missiles is proposed. The law consists of two parts. One is used in the horizontal guidance plane, and the other in the vertical guidance plane. The mid ...A useful mid course guidance law for long range multi purpose missiles is proposed. The law consists of two parts. One is used in the horizontal guidance plane, and the other in the vertical guidance plane. The mid course is combined with variable structure proportional navigation in the homing phase. Simulation results show that the proposed guidance law can meet the demands for starting up the homing phase and so the handing over between mid course guidance and terminal guidance can be carried out successfully.展开更多
Vegetation restoration has been proposed as an effective method for increasing both plant biomass and soil carbon(C) stocks. In this study, 204 publications(733 observations) were analyzed, focusing on the effects of ...Vegetation restoration has been proposed as an effective method for increasing both plant biomass and soil carbon(C) stocks. In this study, 204 publications(733 observations) were analyzed, focusing on the effects of vegetation restoration on soil organic carbon(SOC) in China. The results showed that SOC was increased by 45.33%, 24.43%, 30.29% and 27.98% at soil depths of 0–20 cm, 20–40 cm, 40–60 cm and > 60 cm after vegetation restoration, respectively. Restoration from both cropland and non-cropland increased the SOC content. The conversion of non-cropland was more efficient in SOC accumulation than the conversion of cropland did, especially in > 40 cm layers. In addition, the conversion to planted forest led to greater SOC accumulation than that to other land use did. Conversion period and initial SOC content extended more influence on soil C accumulation as the main factors after vegetation restoration than temperature and precipitation did. The SOC content significantly increased with restoration period after long-term vegetation restoration(> 40 yr), indicating a large potential for further accumulation of carbon in the soil, which could mitigate climate change in the near future.展开更多
City networks have been a critical topic in the fields of urban geography and regional economics. Numerous studies have explored city networks, focusing mainly on infrastructure and industrial networks. Unlike traditi...City networks have been a critical topic in the fields of urban geography and regional economics. Numerous studies have explored city networks, focusing mainly on infrastructure and industrial networks. Unlike traditional urban network of which the major measuring indexes are population sizes and entity industries, online commodity service networks could reflect well the influencing of emerging economies, especially the Internet economy, on city networks. This study analyzes and reveals structural features of China's city networks through online commodity services, providing the internet economic approach on city networks. Results indicate that the core cities of online commodity service networks are mainly concentrated in eastern coastal areas. In addition, spatial polarization and layer structure of network connections are obvious, descending from the centers in eastern China to peripheral cities in central and western China. Online commodity services of different cities show apparent differences and uncertainties in terms of specialization rates of international connection, which presents a tendency toward diversification. Online commodity service networks are not only associated with goods production, supply, and consumption in physical space but also reflect virtual information, capital, and technology flows, thus providing a new empirical approach for understanding city networks in information and internet economic age.展开更多
New nomadism is a movement of global intensification that configures ways of living, inhabiting, and being in the world. The case studies of the temporary residences in Turin, in areas characterized by problems of urb...New nomadism is a movement of global intensification that configures ways of living, inhabiting, and being in the world. The case studies of the temporary residences in Turin, in areas characterized by problems of urban decay and social tensions with a high rate of immigration, are both a technical and social experimental intervention aiming, through the recovery of the existing degraded property, to transform it into a new living model of social housing, from which it will benefit not only the residents but also the entire urban area. The concept of the spaces has profoundly changed. It is no longer tied to the domestic and work sphere only, it now includes all places of associated and collective life.展开更多
The Zhujiang (Pearl) River Delta is one of the most developed Extended Metropolitan Regions (EMR) in China.With the rapid urbanization,the agglomeration of population and industries has emerged,which has led to dramat...The Zhujiang (Pearl) River Delta is one of the most developed Extended Metropolitan Regions (EMR) in China.With the rapid urbanization,the agglomeration of population and industries has emerged,which has led to dramatic changes of spatial structure and land use in this region.With data of high resolution TM remote sensing images and Google Earth maps,this paper identified and analyzed the spatial pattern of the Zhujiang River Delta EMR using Envy and ArcGIS tools.It was found that 1) the industrial land uses were expanding substantially,particularly on the bank sides of the Zhujiang River estuary;2) large-scale housing developments were concentrated in the fringe of metropolitan areas such as those of Guangzhou and Shenzhen;3) a regional transportation network with the spatial pattern of ″1 circle +2 pieces + 3 axes″ had significantly affected the location choice of manufacture enterprises.At the same time,both highly specialized land use and severely mixed land use patterns were identified.As a consequence of the latter,land use efficiency of the whole EMR areas was reduced.Moreover,ecologic and environmental problems were severe.Based on the above analysis,suggestions were given from the viewpoint of spatial safety,land use efficiency,and the reorganization of spatial structure in the Zhujiang River Delta EMR.展开更多
Massive information flows are gen- erated from interactive processing and visua- lizations. To efficiently support information transmission over the Interact, information cen- tric architecture has been recently propo...Massive information flows are gen- erated from interactive processing and visua- lizations. To efficiently support information transmission over the Interact, information cen- tric architecture has been recently proposed. In this paper, we consider an information centric architecture, called the data centric networking architecture to provide communication servi- ces to big data, where a service identifier is used to name the data objects. We propose dif- ferent approaches for the dissemination of data objects in a large-scale data centric network. In particular, we propose various approaches to link the data dissemination approach with the topology of the Internet. Further, we eva- luate the proposed approaches with respect to data delivery efficiency, round-trip time imp- rovement, and deployment cost. Based on the results obtained from this study, it can be sh- own that by disseminating data objects to small ISPs, the data delivery efficiency can be significantly improved within an acceptable deployment cost.展开更多
In the past several decades,SINOPEC has devoted continuously great efforts to the development of DCC technology,the only commercial process using heavy feeds aiming at propylene production.Recently,a series of researc...In the past several decades,SINOPEC has devoted continuously great efforts to the development of DCC technology,the only commercial process using heavy feeds aiming at propylene production.Recently,a series of research breakthroughs have been achieved in molecular refining.Based on the detailed analysis on the complex DCC reaction network,an innovative catalyst technology has been developed to Optimize Catalysis Kinetics (OCK in brief).The deep-cracking process can be improved with optimizing the availability of the active sites.The updated MFI and beta zeolites are used to boost the propylene selectivity.The latest generation catalyst DMMC-1 has been applied commercially.Compared with the best historical records in the past,the propylene yield upon application of the catalyst DMMC-1 increases by 2.4 m% coupled with an improved distribution of products.The DCC technology continues to assume a leading position for manufacturing propylene from heavy feedstocks.展开更多
Sustainability on farms is a challenge to competitiveness in the globalized market. In this scenario, due to the strong environmental, economic and social appeal, crop-livestock-forest integration systems have been co...Sustainability on farms is a challenge to competitiveness in the globalized market. In this scenario, due to the strong environmental, economic and social appeal, crop-livestock-forest integration systems have been considered as the future of agriculture. Regarding the economic approach, this system is based on the diversification of income generating activities, with revenue entry at different times, rationalization of resource use and reduction of risk of financial losses. Thus, the purpose of this work was to carry out the economic analysis of a crop-livestock-forest integration system, located at Boa Vereda's farm, in the municipality of Cachoeira Dourada in the state of Goi^is in the central-west region of Brazil. The system was composed of the following traditional crops of the region: soybean, corn, pasture, beef cattle and eucalyptus. The technical coefficients and the prices used for economic evaluation were obtained from the experimental unit and from the local market when crops were harvested in 2016/2017. The economic indicators used to assess economic viability were the net present value (NPV) and the equivalent annual uniform value (EAUV). The results showed a return greater than the opportunity cost of the land, showing the attractiveness of the crop-livestock-forest integration system. Thus, this system represents an economically viable alternative that, among other benefits, allows the diversification of its sources of income, with a reduction of risk.展开更多
Freshwater biofouling threatens a variety of human activities,from the supply of water and energy to recreation.Several species of freshwater bryozoans are notorious for clogging pipes and filters but have been relati...Freshwater biofouling threatens a variety of human activities,from the supply of water and energy to recreation.Several species of freshwater bryozoans are notorious for clogging pipes and filters but have been relatively poorly studied to date.We report,for the first time,a biofouling species of freshwater bryozoan,Pectinatella magnifica(Leidy,1851),from several freshwater rivers,lakes and ponds in China.A complete description,national distribution and the fouling problems are provided.Exactly how Pectinatella magnifica arrived in China remains unclear,but anthropochory and zoochory are considered to be important dispersal pathways.展开更多
Circulating tumor cells(CTCs) are tumor cells that enter the blood circulation after detaching from the primary tumor and can migrate to reach distant organs, where they can give rise to aggressive metastasis. Clinica...Circulating tumor cells(CTCs) are tumor cells that enter the blood circulation after detaching from the primary tumor and can migrate to reach distant organs, where they can give rise to aggressive metastasis. Clinical studies have revealed that the presence of CTCs in peripheral blood is correlated with disease progression in lung cancer. However, as CTCs are rare cancer cells released from tumors into the bloodstream, both enrichment and sensitive detection methods are technically challenging. In order to best understand how CTCs are currently being deployed, this review mainly focuses on the different detection methods for CTCs. Furthermore, we will describe the clinical impact of circulating tumor cells in lung cancer and discuss their potential use as biomarker to guide the prognosis.展开更多
The infection of the central nervous system (CNS) by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis (NS) is one of the most severe presentations of schistosome infe...The infection of the central nervous system (CNS) by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis (NS) is one of the most severe presentations of schistosome infection. Among the NS symptoms, cerebral invasion is mostly caused by Schistosoma japonicum (S. japonicum), and the spinal cord symptoms are mainly caused by S. mansoni or S. haematobium. There are 2 main pathways by which schistosomes cause NS: egg embolism and worm migration, via either artery or vein system, especially the valveless perivertebral Batson's plexus. The adult worm migrates anomalously through the above pathways to the CNS where they lay eggs. Due to the differences in species of schistosomes and stages of infection, mechanisms vary greatly. The portal hypertension with hepatosplenic schistosomiasis also plays an important role in the pathogenesis. Here the pathways through which NS occurs in the CNS were reviewed.展开更多
Fowl adenovirus serotype 4(FAdV-4)strain SD1511 was isolated from chickens with severe inclusion body hepatitis and hydropericardium syndrome in Shandong Province,China.The isolate was cultured in primary chicken embr...Fowl adenovirus serotype 4(FAdV-4)strain SD1511 was isolated from chickens with severe inclusion body hepatitis and hydropericardium syndrome in Shandong Province,China.The isolate was cultured in primary chicken embryo kidney cells.A study of pathogenicity indicated that SD1511 readily infected 7–35-d-old chickens by intramuscular injection and intranasal and oral routes,causing 50%–100%mortality.The 35-d-old chickens suffered more severe infection than 7-and 21-d-old chickens with mortality highest in the intramuscular injection group.The serum from surviving chickens showed potent viral neutralizing capability.The complete genome of SD1511 was sequenced and analyzed.The strain was found to belong to the FAdV-4 cluster with more than 99%identity with the virulent FAdV-4 strains isolated in China in recent years except for some distinct variations,including deletions of open reading frame 27(ORF27),ORF48,and part of ORF19.Our findings suggest that SD1511 might be used as a prototype strain for the study of pathogenesis and vaccine development.展开更多
文摘A useful mid course guidance law for long range multi purpose missiles is proposed. The law consists of two parts. One is used in the horizontal guidance plane, and the other in the vertical guidance plane. The mid course is combined with variable structure proportional navigation in the homing phase. Simulation results show that the proposed guidance law can meet the demands for starting up the homing phase and so the handing over between mid course guidance and terminal guidance can be carried out successfully.
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05060104)
文摘Vegetation restoration has been proposed as an effective method for increasing both plant biomass and soil carbon(C) stocks. In this study, 204 publications(733 observations) were analyzed, focusing on the effects of vegetation restoration on soil organic carbon(SOC) in China. The results showed that SOC was increased by 45.33%, 24.43%, 30.29% and 27.98% at soil depths of 0–20 cm, 20–40 cm, 40–60 cm and > 60 cm after vegetation restoration, respectively. Restoration from both cropland and non-cropland increased the SOC content. The conversion of non-cropland was more efficient in SOC accumulation than the conversion of cropland did, especially in > 40 cm layers. In addition, the conversion to planted forest led to greater SOC accumulation than that to other land use did. Conversion period and initial SOC content extended more influence on soil C accumulation as the main factors after vegetation restoration than temperature and precipitation did. The SOC content significantly increased with restoration period after long-term vegetation restoration(> 40 yr), indicating a large potential for further accumulation of carbon in the soil, which could mitigate climate change in the near future.
基金Under the auspices of National Natural Science Foundation of China(No.41571146,41701178)China Postdoctoral Science Foundation(No.2016M600393)Natural Science Foundation of Jiangsu Province(No.BK20170639)
文摘City networks have been a critical topic in the fields of urban geography and regional economics. Numerous studies have explored city networks, focusing mainly on infrastructure and industrial networks. Unlike traditional urban network of which the major measuring indexes are population sizes and entity industries, online commodity service networks could reflect well the influencing of emerging economies, especially the Internet economy, on city networks. This study analyzes and reveals structural features of China's city networks through online commodity services, providing the internet economic approach on city networks. Results indicate that the core cities of online commodity service networks are mainly concentrated in eastern coastal areas. In addition, spatial polarization and layer structure of network connections are obvious, descending from the centers in eastern China to peripheral cities in central and western China. Online commodity services of different cities show apparent differences and uncertainties in terms of specialization rates of international connection, which presents a tendency toward diversification. Online commodity service networks are not only associated with goods production, supply, and consumption in physical space but also reflect virtual information, capital, and technology flows, thus providing a new empirical approach for understanding city networks in information and internet economic age.
文摘New nomadism is a movement of global intensification that configures ways of living, inhabiting, and being in the world. The case studies of the temporary residences in Turin, in areas characterized by problems of urban decay and social tensions with a high rate of immigration, are both a technical and social experimental intervention aiming, through the recovery of the existing degraded property, to transform it into a new living model of social housing, from which it will benefit not only the residents but also the entire urban area. The concept of the spaces has profoundly changed. It is no longer tied to the domestic and work sphere only, it now includes all places of associated and collective life.
基金Under the auspices of National Natural Science Foundation of China (No.40901088,40671063)Knowledge Innovation Programs of Chinese Academy of Sciences (No.KZCX2-YW-321)China Postdoctoral Science Foundation (No.20080440513,200902134)
文摘The Zhujiang (Pearl) River Delta is one of the most developed Extended Metropolitan Regions (EMR) in China.With the rapid urbanization,the agglomeration of population and industries has emerged,which has led to dramatic changes of spatial structure and land use in this region.With data of high resolution TM remote sensing images and Google Earth maps,this paper identified and analyzed the spatial pattern of the Zhujiang River Delta EMR using Envy and ArcGIS tools.It was found that 1) the industrial land uses were expanding substantially,particularly on the bank sides of the Zhujiang River estuary;2) large-scale housing developments were concentrated in the fringe of metropolitan areas such as those of Guangzhou and Shenzhen;3) a regional transportation network with the spatial pattern of ″1 circle +2 pieces + 3 axes″ had significantly affected the location choice of manufacture enterprises.At the same time,both highly specialized land use and severely mixed land use patterns were identified.As a consequence of the latter,land use efficiency of the whole EMR areas was reduced.Moreover,ecologic and environmental problems were severe.Based on the above analysis,suggestions were given from the viewpoint of spatial safety,land use efficiency,and the reorganization of spatial structure in the Zhujiang River Delta EMR.
基金supported by the National Science and Technology Major Projects of the Ministry of Science and Technology of China under Grant No.2012ZX03005003the State Key Program of National Natural Science of China under Grant No.61232017+3 种基金the National Basic Research Program of China(973 Program)under Grant No.2013CB329101the National Natural Science Foundation of China under Grants No.61102049,No.61271202the Beijing Natural Science Foundation underGrants No.4132053,No.4122060the Scientific Research Foundation of the Returned Overseas Chinese Scholars of State Education Ministry under Grant No.W13C300010
文摘Massive information flows are gen- erated from interactive processing and visua- lizations. To efficiently support information transmission over the Interact, information cen- tric architecture has been recently proposed. In this paper, we consider an information centric architecture, called the data centric networking architecture to provide communication servi- ces to big data, where a service identifier is used to name the data objects. We propose dif- ferent approaches for the dissemination of data objects in a large-scale data centric network. In particular, we propose various approaches to link the data dissemination approach with the topology of the Internet. Further, we eva- luate the proposed approaches with respect to data delivery efficiency, round-trip time imp- rovement, and deployment cost. Based on the results obtained from this study, it can be sh- own that by disseminating data objects to small ISPs, the data delivery efficiency can be significantly improved within an acceptable deployment cost.
文摘In the past several decades,SINOPEC has devoted continuously great efforts to the development of DCC technology,the only commercial process using heavy feeds aiming at propylene production.Recently,a series of research breakthroughs have been achieved in molecular refining.Based on the detailed analysis on the complex DCC reaction network,an innovative catalyst technology has been developed to Optimize Catalysis Kinetics (OCK in brief).The deep-cracking process can be improved with optimizing the availability of the active sites.The updated MFI and beta zeolites are used to boost the propylene selectivity.The latest generation catalyst DMMC-1 has been applied commercially.Compared with the best historical records in the past,the propylene yield upon application of the catalyst DMMC-1 increases by 2.4 m% coupled with an improved distribution of products.The DCC technology continues to assume a leading position for manufacturing propylene from heavy feedstocks.
文摘Sustainability on farms is a challenge to competitiveness in the globalized market. In this scenario, due to the strong environmental, economic and social appeal, crop-livestock-forest integration systems have been considered as the future of agriculture. Regarding the economic approach, this system is based on the diversification of income generating activities, with revenue entry at different times, rationalization of resource use and reduction of risk of financial losses. Thus, the purpose of this work was to carry out the economic analysis of a crop-livestock-forest integration system, located at Boa Vereda's farm, in the municipality of Cachoeira Dourada in the state of Goi^is in the central-west region of Brazil. The system was composed of the following traditional crops of the region: soybean, corn, pasture, beef cattle and eucalyptus. The technical coefficients and the prices used for economic evaluation were obtained from the experimental unit and from the local market when crops were harvested in 2016/2017. The economic indicators used to assess economic viability were the net present value (NPV) and the equivalent annual uniform value (EAUV). The results showed a return greater than the opportunity cost of the land, showing the attractiveness of the crop-livestock-forest integration system. Thus, this system represents an economically viable alternative that, among other benefits, allows the diversification of its sources of income, with a reduction of risk.
基金Supported by the National Natural Science Foundation of China(Nos.31100407,31471962)
文摘Freshwater biofouling threatens a variety of human activities,from the supply of water and energy to recreation.Several species of freshwater bryozoans are notorious for clogging pipes and filters but have been relatively poorly studied to date.We report,for the first time,a biofouling species of freshwater bryozoan,Pectinatella magnifica(Leidy,1851),from several freshwater rivers,lakes and ponds in China.A complete description,national distribution and the fouling problems are provided.Exactly how Pectinatella magnifica arrived in China remains unclear,but anthropochory and zoochory are considered to be important dispersal pathways.
基金Supported by grants from the Natural Science Foundation of Heilongjiang Province(No.H201335)Development Center for Medical Science and Technology,Ministry of Health,China(No.W2012FZ105)
文摘Circulating tumor cells(CTCs) are tumor cells that enter the blood circulation after detaching from the primary tumor and can migrate to reach distant organs, where they can give rise to aggressive metastasis. Clinical studies have revealed that the presence of CTCs in peripheral blood is correlated with disease progression in lung cancer. However, as CTCs are rare cancer cells released from tumors into the bloodstream, both enrichment and sensitive detection methods are technically challenging. In order to best understand how CTCs are currently being deployed, this review mainly focuses on the different detection methods for CTCs. Furthermore, we will describe the clinical impact of circulating tumor cells in lung cancer and discuss their potential use as biomarker to guide the prognosis.
基金supported by the Science Foundation of the Department of Health, Hubei Province, China (No. XF06D43, XF2008-23)
文摘The infection of the central nervous system (CNS) by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis (NS) is one of the most severe presentations of schistosome infection. Among the NS symptoms, cerebral invasion is mostly caused by Schistosoma japonicum (S. japonicum), and the spinal cord symptoms are mainly caused by S. mansoni or S. haematobium. There are 2 main pathways by which schistosomes cause NS: egg embolism and worm migration, via either artery or vein system, especially the valveless perivertebral Batson's plexus. The adult worm migrates anomalously through the above pathways to the CNS where they lay eggs. Due to the differences in species of schistosomes and stages of infection, mechanisms vary greatly. The portal hypertension with hepatosplenic schistosomiasis also plays an important role in the pathogenesis. Here the pathways through which NS occurs in the CNS were reviewed.
基金the National Key Technology Research and Development Program of China(No.2015BAD12B01)the China Agriculture Research System(No.CARS-40-K13)
文摘Fowl adenovirus serotype 4(FAdV-4)strain SD1511 was isolated from chickens with severe inclusion body hepatitis and hydropericardium syndrome in Shandong Province,China.The isolate was cultured in primary chicken embryo kidney cells.A study of pathogenicity indicated that SD1511 readily infected 7–35-d-old chickens by intramuscular injection and intranasal and oral routes,causing 50%–100%mortality.The 35-d-old chickens suffered more severe infection than 7-and 21-d-old chickens with mortality highest in the intramuscular injection group.The serum from surviving chickens showed potent viral neutralizing capability.The complete genome of SD1511 was sequenced and analyzed.The strain was found to belong to the FAdV-4 cluster with more than 99%identity with the virulent FAdV-4 strains isolated in China in recent years except for some distinct variations,including deletions of open reading frame 27(ORF27),ORF48,and part of ORF19.Our findings suggest that SD1511 might be used as a prototype strain for the study of pathogenesis and vaccine development.