The reverse magnetohydrodynamic(MHD)energy bypass technology is a promising energy redis⁃tribution technology in the scramjet system,in augmented with a power generation equipment to supply the neces⁃sary long-distanc...The reverse magnetohydrodynamic(MHD)energy bypass technology is a promising energy redis⁃tribution technology in the scramjet system,in augmented with a power generation equipment to supply the neces⁃sary long-distance flight airframe power.In this paper,a computational model of the scramjet magnetohydrody⁃namic channel is developed and verified by using the commercial software Fluent.It is found that when the mag⁃netic induction intensity is 1,2,3,4 T,the power generation efficiency is 22.5%,22.3%,22.0%,21.5%,and decreases with the increase of the magnetic induction intensity,and the enthalpy extraction rate is 0.026%,0.1%,0.21%,0.34%,and increases with the increase of the magnetic induction intensity.The deceleration ef⁃fect of electromagnetic action on the airflow in the power channel increases with the increase of magnetic induc⁃tion intensity.The stronger the magnetic field intensity,the more obvious the decreasing effect of fluid Mach num⁃ber in the channel.The power generation efficiency decreases as the magnetic induction intensity increases and the enthalpy extraction rate is reversed.As the local currents gathering at inlet and outlet of the power generation area,total temperature and enthalpy along the flow direction do not vary linearly,and there are maximum and minimum values at inlet and outlet.Increasing the number of electrodes can effectively regulate the percentage of Joule heat dissipation,which can improve the power generation efficiency.展开更多
In the present paper, three new species of Tetrigoidea are described, i.e. Bolivaritettix arcihumerus sp. nov., Tetrix brevicornis sp. nov., Euparatettix motuoensis sp. nov. and the male of Cotysoides tibetanus （Zhen...In the present paper, three new species of Tetrigoidea are described, i.e. Bolivaritettix arcihumerus sp. nov., Tetrix brevicornis sp. nov., Euparatettix motuoensis sp. nov. and the male of Cotysoides tibetanus （Zheng） is first recorded.展开更多
A new species of the genus Macromotettixoides Zheng, Macromotettixoides undulatifemura sp. nov. is described from the Emeishan Area of Sichuan, China. Type specimens are deposited at the Institute of Zoology, Shaanxi ...A new species of the genus Macromotettixoides Zheng, Macromotettixoides undulatifemura sp. nov. is described from the Emeishan Area of Sichuan, China. Type specimens are deposited at the Institute of Zoology, Shaanxi Normal University, Xi＇an, China.展开更多
[Objective] The aim was to study seedling quality of rice sowed at different dates so as to provide theoretical basis for determining the best seeding time.[Method] By investigating the characters of shoot and root of...[Objective] The aim was to study seedling quality of rice sowed at different dates so as to provide theoretical basis for determining the best seeding time.[Method] By investigating the characters of shoot and root of different varieties sowed at different dates,the best seeding time of double-cropping late rice was determined.[Result] The first leaf sheath height and the second leaf length shared significantly positive correlation,which fit the quadratic equation well.The effects of different sowing dates on shoot and root of three rice varieties appeared significant difference.[Conclusion] The best seeding time of Tianyou428 was in June 25-July 2 and that of Tianyou998 and Yuxiangyouzhan was in July 2-9.展开更多
In this paper, five species of Hypatima Hübner and two species of Homoshelas Meyrick are reported from the mainland of China. Among them, two (Hypatima menglana sp. nov. and Homoshelas marginans sp. nov.) are des...In this paper, five species of Hypatima Hübner and two species of Homoshelas Meyrick are reported from the mainland of China. Among them, two (Hypatima menglana sp. nov. and Homoshelas marginans sp. nov.) are described as new to science and one [Hypatima triorthias (Meyrick)] is recorded for the first time from China. The genitalia are figured and key to the species of Hypatima is given.展开更多
[Objective] The aim was to study the simulation mode application in winter wheat north moving.[Method] Based on meteorological data of many years collected in north of Hebei province,and arrangement of multi-location ...[Objective] The aim was to study the simulation mode application in winter wheat north moving.[Method] Based on meteorological data of many years collected in north of Hebei province,and arrangement of multi-location field experiment,mode against cold was constructed considering cold-resistance characteristics of wheat.[Result] Wheat overwintering was forecasted with the help of working mode,results were verified,and the safe northern boundary for wheat overwintering in Hebei was determined in regions below dam in the south of 41°N.[Conclusion] This study provided reference for exploration of dynamic rules of wheat growth,and growth influence by environment and plant technique.展开更多
Abstract： Aulosaphoides flavistigmus, sp. nov. from Yuanan, China is described and illustrated. A key to the Chinese species of the genus Aulosaphoides is provided. Type specimen is deposited in the Beneficial Insect...Abstract： Aulosaphoides flavistigmus, sp. nov. from Yuanan, China is described and illustrated. A key to the Chinese species of the genus Aulosaphoides is provided. Type specimen is deposited in the Beneficial Insects Laboratory, Fujian Agricultural University, Fuzhou, China.展开更多
A new genus and two new species from the family Tenebrionidae of the order Coleoptera of China are reported in this paper,namely Neoblaps gen.nov.,N.huizensis sp.nov.,Dila bomiana sp.nov.The type specimens are preserv...A new genus and two new species from the family Tenebrionidae of the order Coleoptera of China are reported in this paper,namely Neoblaps gen.nov.,N.huizensis sp.nov.,Dila bomiana sp.nov.The type specimens are preserved in the Museum of Hebei University.展开更多
The diesel particulate matter(DPM) emission from diesel powered equipment in underground mines can cause health hazards including cancer to the miners. The understanding of the DPM propagation pattern under realistic ...The diesel particulate matter(DPM) emission from diesel powered equipment in underground mines can cause health hazards including cancer to the miners. The understanding of the DPM propagation pattern under realistic mining condition is required for selecting proper DPM control strategies and to improve working practices in underground mines. In this paper, three dimensional simulations of DPM emission from the exhaust tail pipe of a load-haul-dump(LHD) vehicle and its subsequent distribution inside an isolated zone in the typical underground mine are carried out using two different solution models available in Ansys Fluent. The incoming fresh air into the isolated zone is treated as a continuous phase and DPM is treated either as a continuous phase(gas) or as a secondary discrete phase(particle). Species transport model is used when DPM is treated as gas and discrete phase model is used when DPM is assumed to behave like a particle. The distributions of DPM concentration inside the isolated zone obtained from each method are presented and compared. From the comparison results, an accurate and economical solution technique for DPM evaluation can be selected.展开更多
In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining...In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining 2o% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.展开更多
Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-...Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-at-age and earlier age-at-maturation.In this study,we simulated a fish population with size characteristics of trawl fishing and the population produces one generation of offspring and lives for one year,used trawl to exploit the simulated fish population,and captured individuals by body size.We evaluated the impact of the changes on selectivity parameters,such as selective range and the length at 50% retention.Under fishing pressure,we specified the selectivity parameters,and determined that smaller selection rates and greater length at 50% retention were associated with an increased tendency towards miniaturization.展开更多
The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) has been used to investigate the extra-area effects of silver iodide (AgI) seeding on stratiform clouds performed at the supercooled layer.A bulk two-moment m...The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) has been used to investigate the extra-area effects of silver iodide (AgI) seeding on stratiform clouds performed at the supercooled layer.A bulk two-moment microphysical scheme and the new software package for silver iodide are incorporated in MM5.Extra conservation equations are applied to trace the seeding agent,which is transported along the flow field and interacts with the supercooled cloud fields.In this study,the model was run using three nested grids,with 3.3 km × 3.3 km horizontal resolution in the finest grid.The model results showed that seeding with AgI at the 5 to 15℃ levels had microphysical effects on the simulated clouds and that the simulation produced a longer-lasting seeding effect because of the transport of the seeding agent by upper-level winds.Most of the AgI particles acted as deposition nuclei,and the deposition nucleation process contributed mostly to additional cloud ice formation in this study.The results showed that more precipitation results from seeded than unseeded case,and the precipitation was redistributed downwind of the target.Augmented precipitation (varying from 5% to 25% downwind) was confined in space to within 250 km of the seeding target and in time to the 3-h period after initial seeding.展开更多
文摘The reverse magnetohydrodynamic(MHD)energy bypass technology is a promising energy redis⁃tribution technology in the scramjet system,in augmented with a power generation equipment to supply the neces⁃sary long-distance flight airframe power.In this paper,a computational model of the scramjet magnetohydrody⁃namic channel is developed and verified by using the commercial software Fluent.It is found that when the mag⁃netic induction intensity is 1,2,3,4 T,the power generation efficiency is 22.5%,22.3%,22.0%,21.5%,and decreases with the increase of the magnetic induction intensity,and the enthalpy extraction rate is 0.026%,0.1%,0.21%,0.34%,and increases with the increase of the magnetic induction intensity.The deceleration ef⁃fect of electromagnetic action on the airflow in the power channel increases with the increase of magnetic induc⁃tion intensity.The stronger the magnetic field intensity,the more obvious the decreasing effect of fluid Mach num⁃ber in the channel.The power generation efficiency decreases as the magnetic induction intensity increases and the enthalpy extraction rate is reversed.As the local currents gathering at inlet and outlet of the power generation area,total temperature and enthalpy along the flow direction do not vary linearly,and there are maximum and minimum values at inlet and outlet.Increasing the number of electrodes can effectively regulate the percentage of Joule heat dissipation,which can improve the power generation efficiency.
文摘In the present paper, three new species of Tetrigoidea are described, i.e. Bolivaritettix arcihumerus sp. nov., Tetrix brevicornis sp. nov., Euparatettix motuoensis sp. nov. and the male of Cotysoides tibetanus （Zheng） is first recorded.
基金supported by the National Natural Science Foundation of China (31160433)the Guangxi Natural Science Foundation (0991266)
文摘A new species of the genus Macromotettixoides Zheng, Macromotettixoides undulatifemura sp. nov. is described from the Emeishan Area of Sichuan, China. Type specimens are deposited at the Institute of Zoology, Shaanxi Normal University, Xi＇an, China.
基金Supported by Program for Agricultural Weather Forecast Technical Re-search of Guangdong Province (GYHY200906021)Science and Tech-nology Planning Project of Guangdong Province (2008A030203013)~~
文摘[Objective] The aim was to study seedling quality of rice sowed at different dates so as to provide theoretical basis for determining the best seeding time.[Method] By investigating the characters of shoot and root of different varieties sowed at different dates,the best seeding time of double-cropping late rice was determined.[Result] The first leaf sheath height and the second leaf length shared significantly positive correlation,which fit the quadratic equation well.The effects of different sowing dates on shoot and root of three rice varieties appeared significant difference.[Conclusion] The best seeding time of Tianyou428 was in June 25-July 2 and that of Tianyou998 and Yuxiangyouzhan was in July 2-9.
文摘In this paper, five species of Hypatima Hübner and two species of Homoshelas Meyrick are reported from the mainland of China. Among them, two (Hypatima menglana sp. nov. and Homoshelas marginans sp. nov.) are described as new to science and one [Hypatima triorthias (Meyrick)] is recorded for the first time from China. The genitalia are figured and key to the species of Hypatima is given.
基金supported by the National Natural Science Foundation of China (31101653,30870329)Fauna of China (FY120100)+1 种基金Tianjin City High School Science & Technology Fund Planning Project (20090608)Tianjin Normal University Talent Introduction Foundation (5RL104)
文摘One new species, Paracladopelma demissum sp. nov., from Sichuan Province in China, is described and illustrated.
基金Supported by Hebei Program for Science and Technology Development~~
文摘[Objective] The aim was to study the simulation mode application in winter wheat north moving.[Method] Based on meteorological data of many years collected in north of Hebei province,and arrangement of multi-location field experiment,mode against cold was constructed considering cold-resistance characteristics of wheat.[Result] Wheat overwintering was forecasted with the help of working mode,results were verified,and the safe northern boundary for wheat overwintering in Hebei was determined in regions below dam in the south of 41°N.[Conclusion] This study provided reference for exploration of dynamic rules of wheat growth,and growth influence by environment and plant technique.
文摘Abstract： Aulosaphoides flavistigmus, sp. nov. from Yuanan, China is described and illustrated. A key to the Chinese species of the genus Aulosaphoides is provided. Type specimen is deposited in the Beneficial Insects Laboratory, Fujian Agricultural University, Fuzhou, China.
文摘A new genus and two new species from the family Tenebrionidae of the order Coleoptera of China are reported in this paper,namely Neoblaps gen.nov.,N.huizensis sp.nov.,Dila bomiana sp.nov.The type specimens are preserved in the Museum of Hebei University.
基金financial support provided by the Western US Mining Safety and Health Training&Translation Center by the National Institute for Occupational Safety and Health(NIOSH)
文摘The diesel particulate matter(DPM) emission from diesel powered equipment in underground mines can cause health hazards including cancer to the miners. The understanding of the DPM propagation pattern under realistic mining condition is required for selecting proper DPM control strategies and to improve working practices in underground mines. In this paper, three dimensional simulations of DPM emission from the exhaust tail pipe of a load-haul-dump(LHD) vehicle and its subsequent distribution inside an isolated zone in the typical underground mine are carried out using two different solution models available in Ansys Fluent. The incoming fresh air into the isolated zone is treated as a continuous phase and DPM is treated either as a continuous phase(gas) or as a secondary discrete phase(particle). Species transport model is used when DPM is treated as gas and discrete phase model is used when DPM is assumed to behave like a particle. The distributions of DPM concentration inside the isolated zone obtained from each method are presented and compared. From the comparison results, an accurate and economical solution technique for DPM evaluation can be selected.
基金the Korea Forest Service for funding this research(Project No.S211316L020130)
文摘In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining 2o% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.
基金Supported by the Special Fund for Agro-scientific Research in the Public Interest of China(No.201203018)the National Key Technology Research and Development Program of China(No.2006BAD09A05)
文摘Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-at-age and earlier age-at-maturation.In this study,we simulated a fish population with size characteristics of trawl fishing and the population produces one generation of offspring and lives for one year,used trawl to exploit the simulated fish population,and captured individuals by body size.We evaluated the impact of the changes on selectivity parameters,such as selective range and the length at 50% retention.Under fishing pressure,we specified the selectivity parameters,and determined that smaller selection rates and greater length at 50% retention were associated with an increased tendency towards miniaturization.
基金supported by the National Natural Science Foundation of China (Grant No. 40805056)the National Key Technologies R&D Program of China (Grant No. 2006BAC12B00)
文摘The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) has been used to investigate the extra-area effects of silver iodide (AgI) seeding on stratiform clouds performed at the supercooled layer.A bulk two-moment microphysical scheme and the new software package for silver iodide are incorporated in MM5.Extra conservation equations are applied to trace the seeding agent,which is transported along the flow field and interacts with the supercooled cloud fields.In this study,the model was run using three nested grids,with 3.3 km × 3.3 km horizontal resolution in the finest grid.The model results showed that seeding with AgI at the 5 to 15℃ levels had microphysical effects on the simulated clouds and that the simulation produced a longer-lasting seeding effect because of the transport of the seeding agent by upper-level winds.Most of the AgI particles acted as deposition nuclei,and the deposition nucleation process contributed mostly to additional cloud ice formation in this study.The results showed that more precipitation results from seeded than unseeded case,and the precipitation was redistributed downwind of the target.Augmented precipitation (varying from 5% to 25% downwind) was confined in space to within 250 km of the seeding target and in time to the 3-h period after initial seeding.
