The low temperature process of cold dew wind( from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature,combined with the background information of rice cultivation...The low temperature process of cold dew wind( from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature,combined with the background information of rice cultivation from multi-source satellite database together with an reference to the monitoring indexes of cold dew wind disaster to verify the precision of CLDAS data,so as to provide a reference for monitoring chilling damage caused by cold dew wind in late rice production in Guangxi. The results showed that the cold wind dew caused heavy damage to an area of 3 159. 76 km^2,moderate damage to an area of 559. 77 km^2 and light damage to an area of 2 452. 14 km^2. The correlation coefficients between CLDAS inversion temperature and actual temperature of 12 verification meteorological stations were all larger than 0. 93,and the difference in daily average temperature was 0. 3 ℃. The time difference between maximum and minimum temperature provided by CLDAS and corresponding actual temperature from 12 meteorological stations was less than 1 h. The temperature data provided by CLDAS was in accordance with actual temperature data. With an advantage of rapidly,minutely and accurately monitoring the grade distribution of local cold dew wind disaster for late rice,CLDAS can be used in monitoring cold dew wind in late rice production in Guangxi.展开更多
Due to its unique economic value,Moringa oleifera Lam. has become a tree species with great development potential. This paper firstly introduced the value of development and utilization of M. oleifera in nutrition,med...Due to its unique economic value,Moringa oleifera Lam. has become a tree species with great development potential. This paper firstly introduced the value of development and utilization of M. oleifera in nutrition,medicinal,industrial,greening,etc. Then,focusing on the current development status of M. oleifera industry in Guangxi and combining Guangxi's resource conditions,it came up with recommendations for the comprehensive development and rational utilization of M. oleifera. Besides,it made a prediction of the prospect of Se-enriched M.oleifera industry in Guangxi.展开更多
Wave-current interaction and its effects on the hydrodynamic environment in the Beibu Gulf(BG) have been investigated via employing the Coupled Ocean–Atmosphere–Wave–Sediment Transport(COAWST) modeling system. The ...Wave-current interaction and its effects on the hydrodynamic environment in the Beibu Gulf(BG) have been investigated via employing the Coupled Ocean–Atmosphere–Wave–Sediment Transport(COAWST) modeling system. The model could simulate reasonable hydrodynamics in the BG when validated by various observations.Vigorous tidal currents refract the waves efficiently and make the seas off the west coast of Hainan Island be the hot spot where currents modulate the significant wave height dramatically. During summer, wave-enhanced bottom stress could weaken the near-shore component of the gulf-scale cyclonic-circulation in the BG remarkably, inducing two major corresponding adjustments: Model results reveal that the deep-layer cold water from the southern BG makes critical contribution to maintaining the cold-water mass in the northern BG Basin.However, the weakened background circulation leads to less cold water transported from the southern gulf to the northern gulf, which finally triggers a 0.2℃ warming in the cold-water mass area;In the top areas of the BG, the suppressed background circulation reduces the transport of the diluted water to the central gulf. Therefore, more freshwater could be trapped locally, which then triggers lower sea surface salinity(SSS) in the near-field and higher SSS in the far-field.展开更多
Ag-sheathed BiPbSrCaO(2223)superconducting tapes prepared by the powder-in-tube technique wereinVeSgated. The Mswt of M layCr and the Jc at 77 K are spengly dspendent on the amouDt ofcold wotheg and annchg condition. ...Ag-sheathed BiPbSrCaO(2223)superconducting tapes prepared by the powder-in-tube technique wereinVeSgated. The Mswt of M layCr and the Jc at 77 K are spengly dspendent on the amouDt ofcold wotheg and annchg condition. The Jc bo by uhahal tw aha drawing and rolling. TheOPbown annwtg theperawt, boe and coohag de tO madrihe Jc vaiueS were in the range 84()-- 850t,1bo^2bo h and 50-- loot / h, nyhvejy. The mndum tuSPOrt Jt at 77 K under zero mopetic field wasl.33 x l04 A / cm2.展开更多
First,current situation of rocky desertification control in Guangxi was surveyed via the methods of literature review,field investigation and informal discussion. The results displayed that new progress has been made ...First,current situation of rocky desertification control in Guangxi was surveyed via the methods of literature review,field investigation and informal discussion. The results displayed that new progress has been made in the study of control techniques and models for rocky desertification in Guangxi,and typical control models of " mountain-water-field-forest-road comprehensive control", " ecological agriculture planting-agricultural tourism", " three-in-one" appeared. Then,systematic analysis on the situation of rocky desertification control in Guangxi was conducted. Some problems are found: at present,the prevention and control mechanism of rocky desertification in Guangxi is not perfect,and there is no joint force among departments;there is low capital input and single source channel;the contradiction between survival and ecology is prominent,and the enthusiasm of the masses to participate is not high;there is imperfect supporting policy mechanism,and economic development and ecological protection are unbalanced. For these problems,relevant suggestions and safeguard measures are proposed from comprehensive management,governance planning,technical support and policy support. The research aims to provide theoretical foundation and scientific basis for future rocky desertification control in Guangxi.展开更多
The evolution of two-component cold atoms on a ring with spin–orbit coupling has been studied analytically for the case with N noninteracting particles.Then,the effect of interaction is evaluated numerically via a tw...The evolution of two-component cold atoms on a ring with spin–orbit coupling has been studied analytically for the case with N noninteracting particles.Then,the effect of interaction is evaluated numerically via a two-body system.Two cases are considered:(i) Starting from a ground state the evolution is induced by a sudden change of the laser field,and(ii)the evolution starting from a superposition state.Oscillating persistent spin-currents have been found.A set of formulae have been derived to describe the period and amplitude of the oscillation.Based on these formulae the oscillation can be well controlled via adjusting the parameters of the laser beams.In particular,it is predicted that movable stripes might emerge on the ring.展开更多
In order to find out the situation of the innovation and development of the flower industry in Guangxi,the paper analyzed the development status of flower industry in Guangxi,summarized the achievements and experience...In order to find out the situation of the innovation and development of the flower industry in Guangxi,the paper analyzed the development status of flower industry in Guangxi,summarized the achievements and experience of technological innovation,and the prominent problems in the development of flower industry.On the basis of the analysis,it came up with some recommendations for the development of the flower industry in Guangxi,so as to provide theoretical reference for the development of the flower industry in Guangxi.展开更多
The generation of high-resolution data is increasingly important in understanding the complexities of coastal ocean and developing sound management strategies, especially in view of the long-term impact of severe weat...The generation of high-resolution data is increasingly important in understanding the complexities of coastal ocean and developing sound management strategies, especially in view of the long-term impact of severe weather systems. The impact of severe weather systems, when integrated over time, can be significant when compared with tidal oscillations. This paper presents a study of water transport out of Vermilion Bay in response to a short,intense event associated with a passing atmospheric cold front, and reports the application of an Acoustic Doppler Current Profiler(ADCP) mounted on an Automated Surface Craft(ASC), known as the auto-boat or unmanned boat, developed in our lab at the Louisiana State University, to generate high resolution data accurately at a fraction of the cost of a manned boat. In our study, we used a manned boat and an unmanned boat, each for over 24 h to cover an entire diurnal tidal cycle, to measure flow velocity profiles to calculate the total transport. A stationary ADCP was deployed in the Southwest Pass of the Vermilion Bay from May 2009 to April2012, providing data almost continuously(with only one major gap), with a 717-day record of water transport between the northern Gulf of Mexico and Vermilion Bay, and demonstrates the importance of the pass in water transport.展开更多
The effect of cold high pressure densification(CHPD)on anisotropy of the critical current density(Jc)in《in situ》single core binary and alloyed MgB2 tapes has been determined as a function of temperatures at 4.2 K,20...The effect of cold high pressure densification(CHPD)on anisotropy of the critical current density(Jc)in《in situ》single core binary and alloyed MgB2 tapes has been determined as a function of temperatures at 4.2 K,20 K and 25 K as well as at applied magnetic fields up to 19 T.The study includes binary and C4H6O5(malic acid)doped MgB2 tapes before and after CHPD.It is remarkable that the CHPD process not only improved the Jc values,in particular at the higher magnetic fields,but also decreased the anisotropy ratio,Г=JC^///JC^⊥In binary MgB2 tapes,the anisotropy factor F increases with higher aspect ratios,even after applying CHPD.In malic acid(C4H6O5)doped tapes,however,the application of CHPD leads only to small enhancements ofГ,even for higher aspect ratios.This is attributed to the higher carbon content in the MgB2 filaments,which in turn is a consequence of the reduced chemical reaction path in the densified filaments.At all applied field values,it was found that CHPD processed C4H6O5 doped tapes exhibit an almost isotropic behavior.This constitutes an advantage in view of industrial magnet applications using wires with square or slightly rectangular configuration.展开更多
Based on the conventional meteorological data and the NCEP/NCAR 1° × 1° reanalysis data and those related to mid-scale automatic station, satellite cloud picture and radar return, with the dynamic...Based on the conventional meteorological data and the NCEP/NCAR 1° × 1° reanalysis data and those related to mid-scale automatic station, satellite cloud picture and radar return, with the dynamic diagnosis analysis method, an analysis is made on the process of the convective rainstorm of quasi-stationary front triggered by the weak cold air on June 4-7, 2014, showing: 1) the process occurred in the event of convection of a stationary front triggered by the eastward moving south trough and the southward moving weak cold air from west under the background of circulation of two ridges and one trough at the Asian-European mid-high latitude and weakening and southeastward moving subtropical high;2) a system configuration that contributes to convective rainstorms formed in the event of the convergence of low-level moisture, upper-level divergence and the continuous vertical ascending motion after the 200 hPa upper-level jet stream moved westwards from east and the 850 hPa southwest jet stream intensified;3) after the intrusion by weak cold air of the meso-scale katallobaric area formed by the accumulated warm moist air of Guangxi before the intrusion, the warm moist air rose to trigger convection;convection cells developed and spread nearby the boundary between anallobaric area and katallobaric area, during which total 5 MCSs developed and each formed a rainstorm center at the part where the MCSs coincide;a meso-scale katallobaric area forms and develops 2 - 5 hours earlier than convection, so that it is also a warning of heavy rains.展开更多
综述了涉及工程应用的冷丝熔化极气体保护焊(Cold wire gas metal arc welding,CW-GMAW)熔滴过渡形态特征。结果表明,在大电流、强规范、富氩混合气体保护下,CW-GMAW工艺的熔滴过渡形态呈喷射过渡;当电流较小、电弧电压较低时,可能为滴...综述了涉及工程应用的冷丝熔化极气体保护焊(Cold wire gas metal arc welding,CW-GMAW)熔滴过渡形态特征。结果表明,在大电流、强规范、富氩混合气体保护下,CW-GMAW工艺的熔滴过渡形态呈喷射过渡;当电流较小、电弧电压较低时,可能为滴状过渡,甚至在弧压很低时,呈现短路过渡形态。该工艺电弧发生偏向冷丝的位移,弧长变短甚至发生短路,与冷丝送进速率比增高及冷丝在电弧中产生大量金属蒸气时弧柱电阻下降有关。在具有富氩混合保护气体的相同工艺参数下,CWGMAW转变电流比GMAW降低了4%~7%。焊接工艺参数对CW-GMAW和GMAW工艺熔滴过渡形态的影响规律大致相近,但前者因涉及冷丝送进速率比和电极焊丝送进速度,以及它们的匹配等,使焊接电流的影响更为复杂。展开更多
A two-month seabed-mounted observation(YSG1 area) was carried out in the western Yellow Sea Cold Water Mass(YSCWM) using an RDI-300 K acoustic Doppler current profiler(ADCP) placed at a water depth of 38 m in late sum...A two-month seabed-mounted observation(YSG1 area) was carried out in the western Yellow Sea Cold Water Mass(YSCWM) using an RDI-300 K acoustic Doppler current profiler(ADCP) placed at a water depth of 38 m in late summer, 2012. On August 2012, Typhoon Bolaven passed east of YSG1 with a maximum wind speed of 20 m s-1. The water depth, bottom temperature, and profile current velocities(including u, v and w components) were measured, and the results showed that the typhoon could induce horizontal current with speed greater than 70 cm s-1 in the water column, which is especially rare at below 20 meters above bottom(mab). The deepening velocity shear layer had an intense shear velocity of around 10 cm s-1 m-1, which indicated the deepening of the upper mixed layer. In the upper water column(above 20 mab), westward de-tide current with velocity greater than 30 cm s-1 was generated with the typhoon's onshore surge, and the direction of current movement shifted to become southward. In the lower water column, a possible pattern of eastward compensation current and delayed typhoon-driven current was demonstrated. During the typhoon, bottom temperature variation was changed into diurnal pattern because of the combined influence of typhoon and tidal current. The passage of Bolaven greatly intensified local sediment resuspension in the bottom layer. In addition, low-density particles constituted the suspended particulate matter(SPM) around 10 mab, which may be transported from the central South Yellow Sea by the typhoon. Overall, the intensive external force of the Typhoon Bolaven did not completely destroy the local thermocline, and most re-suspended sediments during the typhoon were restricted within the YSCWM.展开更多
On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East Chi...On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method.The Kuroshio flows northeastward through eastern part of the investigated region and has the main coreat Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy be-tween these two northward flows, and a weak cyclonic eddy at the western part of Section PN. Theabove current structure is one type of the current structures at Section PN in ECS. The net northwardvolume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB)through Section PN is about 26.2× 106 m3/s in June 1999. The VT of the inshore branch of TaiwanWarm CArrent (TWCIB) through the investigated region is about 0.4 × 106 m3/s. The Taiwan WarmCurrent (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea CoastalCurrent (HSCC) flows southeastward and enters into the northwestern part of investigated region, andflows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan WarmCurrent and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea CoastalCurrent flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and coldwater is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 atthe northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).展开更多
The concentration of suspended load can be determined by its linear relationship to turbidity.Our results present the basic distribution of suspended load in North Yellow Sea.In summer,the suspended load concentration...The concentration of suspended load can be determined by its linear relationship to turbidity.Our results present the basic distribution of suspended load in North Yellow Sea.In summer,the suspended load concentration is high along the coast and low in the center of the sea.There are four regions of high concentration in the surface layer:Penglai and Chengshantou along the north of the Shandong Peninsula,and the coastal areas of Lüshun and Changshan Islands.There is a 2 mg/L contour at 124°E that separates the North Yellow Sea from regions of lower concentrations in the open sea to the west.And there is a 2 mg/L contour at 124°E that separates the North Yellow Sea from regions of lower concentrations in the open sea to the west.The distribution features in the 10 m and bottom layer are similar to the surface layer,however,the suspended load concentration declines in the 10 m layer while it increases in the bottom layer.And in the bottom layer there is a low suspended load concentration water mass at the region south of 38°N and east of 123°E extending to the southeast.In general,the lowest suspended load concentration in a vertical profile is at a depth of 10 to 20 m,the highest suspended load concentration is in the bottom near Chengshantou area.In winter,the distribution of suspended load is similar to summer,but the average concentrations are three times higher.There are two tongue-shaped high suspended load concentration belt,one occurring from surface to seafloor,extends to the north near Chengshantou and the other invades north to south along the east margin of Dalian Bay.They separate the low suspended load concentration water masses in the center of North Yellow Sea into east and west parts.Vertical distribution is quite uniform in the whole North Yellow Sea because of the cooling effect and strong northeast winds.The distribution of suspended load has a very close relationship to the current circulation and wind-induced waves in the North Yellow Sea.Because of this,we have been able to show for the first time that the distribution of suspended load can be used to identify water masses.展开更多
Satellite remote sensing observations show that during winter, sea surface temperature (SST) presents the structure of double warm tongues in the Huanghai Sea trough: the western and the eastern warm tongues. Numerica...Satellite remote sensing observations show that during winter, sea surface temperature (SST) presents the structure of double warm tongues in the Huanghai Sea trough: the western and the eastern warm tongues. Numerical experiments based on POM are carried out to study the forming mechanism of this thermal structure and its relation to the Huanghai Sea Warm Current (HSWC). The control experiment reproduces this phenomenon quite well, and comparing experiments inves-tigate the effect of wind and tide. It is found that the western warm tongue is mainly caused by the HSWC, which can be strengthened by wintertime southward wind. The eastern warm tongue develops under the influence of an anti-clockwise circulation which is induced by the temperature front of the Huanghai Sea Cold Water Mass (HSCWM) in summer and autumn. In the eastern portion of this circulation, the northward current carries warm water to the north, forming the eastern warm tongue, which remains till winter.展开更多
基金Supported by the National Agricultural Science and Technology Achievements Transformation Project of China(2014GB2E100281)the Science and Technology Key R&D Program of Guangxi(Guike AB17195037)
文摘The low temperature process of cold dew wind( from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature,combined with the background information of rice cultivation from multi-source satellite database together with an reference to the monitoring indexes of cold dew wind disaster to verify the precision of CLDAS data,so as to provide a reference for monitoring chilling damage caused by cold dew wind in late rice production in Guangxi. The results showed that the cold wind dew caused heavy damage to an area of 3 159. 76 km^2,moderate damage to an area of 559. 77 km^2 and light damage to an area of 2 452. 14 km^2. The correlation coefficients between CLDAS inversion temperature and actual temperature of 12 verification meteorological stations were all larger than 0. 93,and the difference in daily average temperature was 0. 3 ℃. The time difference between maximum and minimum temperature provided by CLDAS and corresponding actual temperature from 12 meteorological stations was less than 1 h. The temperature data provided by CLDAS was in accordance with actual temperature data. With an advantage of rapidly,minutely and accurately monitoring the grade distribution of local cold dew wind disaster for late rice,CLDAS can be used in monitoring cold dew wind in late rice production in Guangxi.
基金Supported by Scientific Research and Technological Development Program of Xixiangtang District of Nanning City(201710304)Key Research and Development Program of Guangxi(Gui Ke AB16380088)+5 种基金Guangxi Se-enriched Crop Experiment Station(Gui TS2016011)Key Research and Development Program of Qingxiu District of Nanning City(2016039)Scientific Development Fund Project of Guangxi Academy of Agricultural Sciences(2017JM01,2017JM03,2015JM23)Technological Achievement Transformation Project of Guangxi Academy of Agricultural Sciences(2017NZ04)Key Science and Technology Project of Guangxi(Gui Ke AA17202026-2)Special Fund Project for Innovation Driven Development of Guangxi(Gui Ke AA17202019,Gui Ke AA17202019-4,and Gui Ke AA17202019-1)
文摘Due to its unique economic value,Moringa oleifera Lam. has become a tree species with great development potential. This paper firstly introduced the value of development and utilization of M. oleifera in nutrition,medicinal,industrial,greening,etc. Then,focusing on the current development status of M. oleifera industry in Guangxi and combining Guangxi's resource conditions,it came up with recommendations for the comprehensive development and rational utilization of M. oleifera. Besides,it made a prediction of the prospect of Se-enriched M.oleifera industry in Guangxi.
基金The Program for Scientific Research Start-up Funds of Guangdong Ocean University under contract No.101302/R18001the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)under contract No.ZJW-2019-08+1 种基金the National Key Research and Development Program of China under contract No.2016YFC1401403the National Natural Science Foundation of China under contract Nos 41476009 and 41776034
文摘Wave-current interaction and its effects on the hydrodynamic environment in the Beibu Gulf(BG) have been investigated via employing the Coupled Ocean–Atmosphere–Wave–Sediment Transport(COAWST) modeling system. The model could simulate reasonable hydrodynamics in the BG when validated by various observations.Vigorous tidal currents refract the waves efficiently and make the seas off the west coast of Hainan Island be the hot spot where currents modulate the significant wave height dramatically. During summer, wave-enhanced bottom stress could weaken the near-shore component of the gulf-scale cyclonic-circulation in the BG remarkably, inducing two major corresponding adjustments: Model results reveal that the deep-layer cold water from the southern BG makes critical contribution to maintaining the cold-water mass in the northern BG Basin.However, the weakened background circulation leads to less cold water transported from the southern gulf to the northern gulf, which finally triggers a 0.2℃ warming in the cold-water mass area;In the top areas of the BG, the suppressed background circulation reduces the transport of the diluted water to the central gulf. Therefore, more freshwater could be trapped locally, which then triggers lower sea surface salinity(SSS) in the near-field and higher SSS in the far-field.
文摘Ag-sheathed BiPbSrCaO(2223)superconducting tapes prepared by the powder-in-tube technique wereinVeSgated. The Mswt of M layCr and the Jc at 77 K are spengly dspendent on the amouDt ofcold wotheg and annchg condition. The Jc bo by uhahal tw aha drawing and rolling. TheOPbown annwtg theperawt, boe and coohag de tO madrihe Jc vaiueS were in the range 84()-- 850t,1bo^2bo h and 50-- loot / h, nyhvejy. The mndum tuSPOrt Jt at 77 K under zero mopetic field wasl.33 x l04 A / cm2.
基金Supported by the Project of"Investigation on the Current Situation of Rocky Desertification Control in Guangxi"(GNH[2017]B-03)。
文摘First,current situation of rocky desertification control in Guangxi was surveyed via the methods of literature review,field investigation and informal discussion. The results displayed that new progress has been made in the study of control techniques and models for rocky desertification in Guangxi,and typical control models of " mountain-water-field-forest-road comprehensive control", " ecological agriculture planting-agricultural tourism", " three-in-one" appeared. Then,systematic analysis on the situation of rocky desertification control in Guangxi was conducted. Some problems are found: at present,the prevention and control mechanism of rocky desertification in Guangxi is not perfect,and there is no joint force among departments;there is low capital input and single source channel;the contradiction between survival and ecology is prominent,and the enthusiasm of the masses to participate is not high;there is imperfect supporting policy mechanism,and economic development and ecological protection are unbalanced. For these problems,relevant suggestions and safeguard measures are proposed from comprehensive management,governance planning,technical support and policy support. The research aims to provide theoretical foundation and scientific basis for future rocky desertification control in Guangxi.
基金Project supported by the National Natural Science Foundation of China(Grant No.10874249)
文摘The evolution of two-component cold atoms on a ring with spin–orbit coupling has been studied analytically for the case with N noninteracting particles.Then,the effect of interaction is evaluated numerically via a two-body system.Two cases are considered:(i) Starting from a ground state the evolution is induced by a sudden change of the laser field,and(ii)the evolution starting from a superposition state.Oscillating persistent spin-currents have been found.A set of formulae have been derived to describe the period and amplitude of the oscillation.Based on these formulae the oscillation can be well controlled via adjusting the parameters of the laser beams.In particular,it is predicted that movable stripes might emerge on the ring.
基金Supported by Science and Technology Major Project of Guangxi(Gui Ke AA17204046)Scientific Research and Technological Development Program Project of Nanning City(20175031-5)+3 种基金Project of Guangxi Academy of Agricultural Sciences(Gui Nong Ke 2015YT89 Gui Nong Ke 2017YZ05 Gui Nong Ke 2017YM44 Gui Nong Ke 2018JZ07)
文摘In order to find out the situation of the innovation and development of the flower industry in Guangxi,the paper analyzed the development status of flower industry in Guangxi,summarized the achievements and experience of technological innovation,and the prominent problems in the development of flower industry.On the basis of the analysis,it came up with some recommendations for the development of the flower industry in Guangxi,so as to provide theoretical reference for the development of the flower industry in Guangxi.
基金The Louisiana Board of Regents EPSCoR(pFund)the Louisiana Board of Regents Traditional Enhancement Program under contract No.LEQSF(2016-17)-ENH-TR-05+1 种基金the North Pacific Research Board under contract No.1229the Louisiana Department of Wildlife and Fisheries under contract No.699775/514-100210
文摘The generation of high-resolution data is increasingly important in understanding the complexities of coastal ocean and developing sound management strategies, especially in view of the long-term impact of severe weather systems. The impact of severe weather systems, when integrated over time, can be significant when compared with tidal oscillations. This paper presents a study of water transport out of Vermilion Bay in response to a short,intense event associated with a passing atmospheric cold front, and reports the application of an Acoustic Doppler Current Profiler(ADCP) mounted on an Automated Surface Craft(ASC), known as the auto-boat or unmanned boat, developed in our lab at the Louisiana State University, to generate high resolution data accurately at a fraction of the cost of a manned boat. In our study, we used a manned boat and an unmanned boat, each for over 24 h to cover an entire diurnal tidal cycle, to measure flow velocity profiles to calculate the total transport. A stationary ADCP was deployed in the Southwest Pass of the Vermilion Bay from May 2009 to April2012, providing data almost continuously(with only one major gap), with a 717-day record of water transport between the northern Gulf of Mexico and Vermilion Bay, and demonstrates the importance of the pass in water transport.
基金This work was supported by the Australian Research Council(Grant No.LP160101784)A.K.thanks the Researchers Supporting Project(RSP-2019/127)King Saud University,Riyadh,Saudi Arabia for the support.This work was performed in part at the Queensland node of the Australian National Fabrication Facility,a company established under the National Collaborative Research Infrastructure Strategy to provide nano-and microfabrication facilities for Australia's researchers.M.M.acknowledges an internal funding project of the University of Osijek(ZUP-2018).
文摘The effect of cold high pressure densification(CHPD)on anisotropy of the critical current density(Jc)in《in situ》single core binary and alloyed MgB2 tapes has been determined as a function of temperatures at 4.2 K,20 K and 25 K as well as at applied magnetic fields up to 19 T.The study includes binary and C4H6O5(malic acid)doped MgB2 tapes before and after CHPD.It is remarkable that the CHPD process not only improved the Jc values,in particular at the higher magnetic fields,but also decreased the anisotropy ratio,Г=JC^///JC^⊥In binary MgB2 tapes,the anisotropy factor F increases with higher aspect ratios,even after applying CHPD.In malic acid(C4H6O5)doped tapes,however,the application of CHPD leads only to small enhancements ofГ,even for higher aspect ratios.This is attributed to the higher carbon content in the MgB2 filaments,which in turn is a consequence of the reduced chemical reaction path in the densified filaments.At all applied field values,it was found that CHPD processed C4H6O5 doped tapes exhibit an almost isotropic behavior.This constitutes an advantage in view of industrial magnet applications using wires with square or slightly rectangular configuration.
文摘Based on the conventional meteorological data and the NCEP/NCAR 1° × 1° reanalysis data and those related to mid-scale automatic station, satellite cloud picture and radar return, with the dynamic diagnosis analysis method, an analysis is made on the process of the convective rainstorm of quasi-stationary front triggered by the weak cold air on June 4-7, 2014, showing: 1) the process occurred in the event of convection of a stationary front triggered by the eastward moving south trough and the southward moving weak cold air from west under the background of circulation of two ridges and one trough at the Asian-European mid-high latitude and weakening and southeastward moving subtropical high;2) a system configuration that contributes to convective rainstorms formed in the event of the convergence of low-level moisture, upper-level divergence and the continuous vertical ascending motion after the 200 hPa upper-level jet stream moved westwards from east and the 850 hPa southwest jet stream intensified;3) after the intrusion by weak cold air of the meso-scale katallobaric area formed by the accumulated warm moist air of Guangxi before the intrusion, the warm moist air rose to trigger convection;convection cells developed and spread nearby the boundary between anallobaric area and katallobaric area, during which total 5 MCSs developed and each formed a rainstorm center at the part where the MCSs coincide;a meso-scale katallobaric area forms and develops 2 - 5 hours earlier than convection, so that it is also a warning of heavy rains.
文摘综述了涉及工程应用的冷丝熔化极气体保护焊(Cold wire gas metal arc welding,CW-GMAW)熔滴过渡形态特征。结果表明,在大电流、强规范、富氩混合气体保护下,CW-GMAW工艺的熔滴过渡形态呈喷射过渡;当电流较小、电弧电压较低时,可能为滴状过渡,甚至在弧压很低时,呈现短路过渡形态。该工艺电弧发生偏向冷丝的位移,弧长变短甚至发生短路,与冷丝送进速率比增高及冷丝在电弧中产生大量金属蒸气时弧柱电阻下降有关。在具有富氩混合保护气体的相同工艺参数下,CWGMAW转变电流比GMAW降低了4%~7%。焊接工艺参数对CW-GMAW和GMAW工艺熔滴过渡形态的影响规律大致相近,但前者因涉及冷丝送进速率比和电极焊丝送进速度,以及它们的匹配等,使焊接电流的影响更为复杂。
基金supported by the National Natural Science Foundation of China (Nos. 41806190, 41030856)National Program on Key Basic Research Project of China (973 Program, No. 2005CB422304)+3 种基金Qingdao Postdoctoral Application Research Project Fundingthe Fundamental Research Funds for the Central Universities (Nos. 20171305, 201562030,20176 2015, 201822027)the Project of Taishan Scholarthe Shared Voyage of National Nature Science Foundation of China for their support
文摘A two-month seabed-mounted observation(YSG1 area) was carried out in the western Yellow Sea Cold Water Mass(YSCWM) using an RDI-300 K acoustic Doppler current profiler(ADCP) placed at a water depth of 38 m in late summer, 2012. On August 2012, Typhoon Bolaven passed east of YSG1 with a maximum wind speed of 20 m s-1. The water depth, bottom temperature, and profile current velocities(including u, v and w components) were measured, and the results showed that the typhoon could induce horizontal current with speed greater than 70 cm s-1 in the water column, which is especially rare at below 20 meters above bottom(mab). The deepening velocity shear layer had an intense shear velocity of around 10 cm s-1 m-1, which indicated the deepening of the upper mixed layer. In the upper water column(above 20 mab), westward de-tide current with velocity greater than 30 cm s-1 was generated with the typhoon's onshore surge, and the direction of current movement shifted to become southward. In the lower water column, a possible pattern of eastward compensation current and delayed typhoon-driven current was demonstrated. During the typhoon, bottom temperature variation was changed into diurnal pattern because of the combined influence of typhoon and tidal current. The passage of Bolaven greatly intensified local sediment resuspension in the bottom layer. In addition, low-density particles constituted the suspended particulate matter(SPM) around 10 mab, which may be transported from the central South Yellow Sea by the typhoon. Overall, the intensive external force of the Typhoon Bolaven did not completely destroy the local thermocline, and most re-suspended sediments during the typhoon were restricted within the YSCWM.
基金National Natural Science Foundation of China under contract No. 40176007Major State Basic Research Program of China under contract No.G 1999043802.
文摘On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method.The Kuroshio flows northeastward through eastern part of the investigated region and has the main coreat Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy be-tween these two northward flows, and a weak cyclonic eddy at the western part of Section PN. Theabove current structure is one type of the current structures at Section PN in ECS. The net northwardvolume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB)through Section PN is about 26.2× 106 m3/s in June 1999. The VT of the inshore branch of TaiwanWarm CArrent (TWCIB) through the investigated region is about 0.4 × 106 m3/s. The Taiwan WarmCurrent (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea CoastalCurrent (HSCC) flows southeastward and enters into the northwestern part of investigated region, andflows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan WarmCurrent and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea CoastalCurrent flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and coldwater is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 atthe northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).
基金Supported by "908 Program" (Nos.908-01-ST02,908-02-02-02)National Natural Science Foundation of China (No.40976001)also China National Basic Research Priorities Programmer (No.2005CB422308)
文摘The concentration of suspended load can be determined by its linear relationship to turbidity.Our results present the basic distribution of suspended load in North Yellow Sea.In summer,the suspended load concentration is high along the coast and low in the center of the sea.There are four regions of high concentration in the surface layer:Penglai and Chengshantou along the north of the Shandong Peninsula,and the coastal areas of Lüshun and Changshan Islands.There is a 2 mg/L contour at 124°E that separates the North Yellow Sea from regions of lower concentrations in the open sea to the west.And there is a 2 mg/L contour at 124°E that separates the North Yellow Sea from regions of lower concentrations in the open sea to the west.The distribution features in the 10 m and bottom layer are similar to the surface layer,however,the suspended load concentration declines in the 10 m layer while it increases in the bottom layer.And in the bottom layer there is a low suspended load concentration water mass at the region south of 38°N and east of 123°E extending to the southeast.In general,the lowest suspended load concentration in a vertical profile is at a depth of 10 to 20 m,the highest suspended load concentration is in the bottom near Chengshantou area.In winter,the distribution of suspended load is similar to summer,but the average concentrations are three times higher.There are two tongue-shaped high suspended load concentration belt,one occurring from surface to seafloor,extends to the north near Chengshantou and the other invades north to south along the east margin of Dalian Bay.They separate the low suspended load concentration water masses in the center of North Yellow Sea into east and west parts.Vertical distribution is quite uniform in the whole North Yellow Sea because of the cooling effect and strong northeast winds.The distribution of suspended load has a very close relationship to the current circulation and wind-induced waves in the North Yellow Sea.Because of this,we have been able to show for the first time that the distribution of suspended load can be used to identify water masses.
基金The National Key Basic Research Program of China under contract 2006CB403605the National Natural Science Foundation of China under contract Nos.40806016 and 40706016China 908–project under contract No. 908–02–01–03
文摘Satellite remote sensing observations show that during winter, sea surface temperature (SST) presents the structure of double warm tongues in the Huanghai Sea trough: the western and the eastern warm tongues. Numerical experiments based on POM are carried out to study the forming mechanism of this thermal structure and its relation to the Huanghai Sea Warm Current (HSWC). The control experiment reproduces this phenomenon quite well, and comparing experiments inves-tigate the effect of wind and tide. It is found that the western warm tongue is mainly caused by the HSWC, which can be strengthened by wintertime southward wind. The eastern warm tongue develops under the influence of an anti-clockwise circulation which is induced by the temperature front of the Huanghai Sea Cold Water Mass (HSCWM) in summer and autumn. In the eastern portion of this circulation, the northward current carries warm water to the north, forming the eastern warm tongue, which remains till winter.
