In order to explore a breeding method for mycoplasmal pneumonia-negative swine population, the purifying effects of combination therapy, SEW and three-point breeding and management system on Mycoplasma hyopneumoniae w...In order to explore a breeding method for mycoplasmal pneumonia-negative swine population, the purifying effects of combination therapy, SEW and three-point breeding and management system on Mycoplasma hyopneumoniae were investigated in this study. After the processes of screening pregnant sows, programmed therapy for sows, SEW, three-point breeding and management in the barrier isolation system and programmed therapy for piglets, the newly-bred piglets were monitored as long as four months by serum antibody detection of Mycoplasma hyopneumoniae and fluorescent quantitative PCR of nose swabs. The results showed that when the newlybred five batches of piglets were older than 35 d, they were all negative by serum antibody detection and nose swab antigen detection. Therefore, the combination therapy, SEW and three-point production and management system can effectively purify Mycoplasma hyopneumoniae, providing theoretical basis and clinical experience for the control and purification of domestic mycoplasmal pneumonia.展开更多
The convective heat transfer and friction behaviors of turbulent tube flow through a straight tape with double-sided delta wings(T-W)have been studied experimentally.In the current work,the T-W formed on the tape was ...The convective heat transfer and friction behaviors of turbulent tube flow through a straight tape with double-sided delta wings(T-W)have been studied experimentally.In the current work,the T-W formed on the tape was used as vortex generators for enhancing the heat transfer coefficient by breakdown of thermal boundary layer and by mixing of fluid flow in tubes.The T-W characteristics are(1)T-W with forward/backward-wing arrangement,(2)T-W with alternate axis(T-WA),(3)three wing-width ratios and(4)wing-pitch ratios.The experimental result reveals that for using the T-W,the increases in the mean Nusselt number(Nu)and friction factor are,respectively,up to 165%and 14.8 times of the plain tube and the maximum thermal performance factor is 1.19.It is also obvious that the T-W with forward-wing gives higher heat transfer rate than one with backward-wing around 7%. The present investigation also shows that the heat transfer rate and friction factor obtained from the T-WA is higher than that from the T-W.In addition,the flow pattern and temperature fields in the T-W tube with both backward and forward wings were also examined numerically.展开更多
Three Gorges Project (TGP),the largest water resources and hydropower project in the world with huge scale and complex techniques,has great comprehensive benefits mainly in flood control,power generation and navigatio...Three Gorges Project (TGP),the largest water resources and hydropower project in the world with huge scale and complex techniques,has great comprehensive benefits mainly in flood control,power generation and navigation improvement.Through 17-year construction and practice,the project has been successfully completed.Some valuable experience from the successful construction of TGP has been gained for the management system and mechanism of hydropower project construction in China.Its construction management mode produces important influences on the management system of domestic capital construction.With combination of the construction management practice of TGP,the characteristics of management system and mechanism are summarized,and the suggestions on current hydropower development system and construction management mode are put forward.展开更多
In this study, taking cultivated land fertility evaluation data for example, we conducted a preliminary study of GIS theory and spatial data management, and construct the frame system of mobile structure based on the ...In this study, taking cultivated land fertility evaluation data for example, we conducted a preliminary study of GIS theory and spatial data management, and construct the frame system of mobile structure based on the three layer structure model of application layer, business logic layer and data layer. Then we established a spatial data storage model, which has unified the data standards and achieved the management of spatial data and attribute database. Taking ArcGIS API for iOS as GIS platform, Xcode as the tool, we have realized the functions of data integration, data query, data statistics and fertilization recommendation, and constructed the management and service platform of mobile fertilization expert system.展开更多
Grassland reconstruction is a major approach to alleviate the‘black beach’in Sanjiangyuan of the Qinghai-Tibetan Plateau.It is vital to understand how to manage the planting grassland after reconstruction.And which ...Grassland reconstruction is a major approach to alleviate the‘black beach’in Sanjiangyuan of the Qinghai-Tibetan Plateau.It is vital to understand how to manage the planting grassland after reconstruction.And which artificial grassland management pattern is more likely to restore the degraded grassland of‘black beach?’To provide the scientific basis for the restoration of‘black beach’,we investigated the changes in vegetation characteristics,soil physicochemical properties and soil microbial community structure of planting grassland under different management patterns,and explored the effect of the management patterns on community succession of planting grassland.In this study,vegetation characteristics and soil physicochemical properties were measured by field investigation and laboratory analyses,respectively.Soil microbial community composition was determined by high-throughput sequencing techniques.The results showed that there were significant differences in vegetation characteristics,soil physicochemical properties and soil microbial community structure of the planting grassland under different management patterns.Actinobacteria and Basidiomycota were mainly controlled by vegetation plant species diversity,aboveground biomass(AGB)and soil organic carbon(SOC).Shannon-Wiener index,AGB and SOC peaked and the relative abundance of amplicon sequence variants annotated by Actinobacteria and Basidiomycota were significantly enriched under the management pattern of the planting once treatment.Additionally,the soil had the highest bacterial diversity and the lowest fungal diversity under the planting once treatment,becoming a‘bacterial’soil.These vegetation characteristics and soil environment were more conducive to overall positive community succession,indicating that the planting once treatment is the most reasonable management pattern for restoring the‘black beach’.展开更多
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund[CX(12)1001-05]~~
文摘In order to explore a breeding method for mycoplasmal pneumonia-negative swine population, the purifying effects of combination therapy, SEW and three-point breeding and management system on Mycoplasma hyopneumoniae were investigated in this study. After the processes of screening pregnant sows, programmed therapy for sows, SEW, three-point breeding and management in the barrier isolation system and programmed therapy for piglets, the newly-bred piglets were monitored as long as four months by serum antibody detection of Mycoplasma hyopneumoniae and fluorescent quantitative PCR of nose swabs. The results showed that when the newlybred five batches of piglets were older than 35 d, they were all negative by serum antibody detection and nose swab antigen detection. Therefore, the combination therapy, SEW and three-point production and management system can effectively purify Mycoplasma hyopneumoniae, providing theoretical basis and clinical experience for the control and purification of domestic mycoplasmal pneumonia.
基金Supported by the Thailand Research Fund(TRF),Office of Higher Education Commission and Mahanakorn University of Technology
文摘The convective heat transfer and friction behaviors of turbulent tube flow through a straight tape with double-sided delta wings(T-W)have been studied experimentally.In the current work,the T-W formed on the tape was used as vortex generators for enhancing the heat transfer coefficient by breakdown of thermal boundary layer and by mixing of fluid flow in tubes.The T-W characteristics are(1)T-W with forward/backward-wing arrangement,(2)T-W with alternate axis(T-WA),(3)three wing-width ratios and(4)wing-pitch ratios.The experimental result reveals that for using the T-W,the increases in the mean Nusselt number(Nu)and friction factor are,respectively,up to 165%and 14.8 times of the plain tube and the maximum thermal performance factor is 1.19.It is also obvious that the T-W with forward-wing gives higher heat transfer rate than one with backward-wing around 7%. The present investigation also shows that the heat transfer rate and friction factor obtained from the T-WA is higher than that from the T-W.In addition,the flow pattern and temperature fields in the T-W tube with both backward and forward wings were also examined numerically.
文摘Three Gorges Project (TGP),the largest water resources and hydropower project in the world with huge scale and complex techniques,has great comprehensive benefits mainly in flood control,power generation and navigation improvement.Through 17-year construction and practice,the project has been successfully completed.Some valuable experience from the successful construction of TGP has been gained for the management system and mechanism of hydropower project construction in China.Its construction management mode produces important influences on the management system of domestic capital construction.With combination of the construction management practice of TGP,the characteristics of management system and mechanism are summarized,and the suggestions on current hydropower development system and construction management mode are put forward.
文摘In this study, taking cultivated land fertility evaluation data for example, we conducted a preliminary study of GIS theory and spatial data management, and construct the frame system of mobile structure based on the three layer structure model of application layer, business logic layer and data layer. Then we established a spatial data storage model, which has unified the data standards and achieved the management of spatial data and attribute database. Taking ArcGIS API for iOS as GIS platform, Xcode as the tool, we have realized the functions of data integration, data query, data statistics and fertilization recommendation, and constructed the management and service platform of mobile fertilization expert system.
基金financially supported by the‘Strategic Leading Science&Technology Program’of the Chinese Academy of Sciences(XDA23060604)the Chinese Academy of Sciences‘Light of West China’Program,the Second.Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK0302)+1 种基金the National Natural Science Foundation of China(31770501)Key Laboratory of Ecology and Environment in Minority Areas(Minzu University of China),National Ethnic Affairs Commission(KLEEMA202103).
文摘Grassland reconstruction is a major approach to alleviate the‘black beach’in Sanjiangyuan of the Qinghai-Tibetan Plateau.It is vital to understand how to manage the planting grassland after reconstruction.And which artificial grassland management pattern is more likely to restore the degraded grassland of‘black beach?’To provide the scientific basis for the restoration of‘black beach’,we investigated the changes in vegetation characteristics,soil physicochemical properties and soil microbial community structure of planting grassland under different management patterns,and explored the effect of the management patterns on community succession of planting grassland.In this study,vegetation characteristics and soil physicochemical properties were measured by field investigation and laboratory analyses,respectively.Soil microbial community composition was determined by high-throughput sequencing techniques.The results showed that there were significant differences in vegetation characteristics,soil physicochemical properties and soil microbial community structure of the planting grassland under different management patterns.Actinobacteria and Basidiomycota were mainly controlled by vegetation plant species diversity,aboveground biomass(AGB)and soil organic carbon(SOC).Shannon-Wiener index,AGB and SOC peaked and the relative abundance of amplicon sequence variants annotated by Actinobacteria and Basidiomycota were significantly enriched under the management pattern of the planting once treatment.Additionally,the soil had the highest bacterial diversity and the lowest fungal diversity under the planting once treatment,becoming a‘bacterial’soil.These vegetation characteristics and soil environment were more conducive to overall positive community succession,indicating that the planting once treatment is the most reasonable management pattern for restoring the‘black beach’.
