Objective To probe into the effective acupuncture treatment for high fever and other clinical relevant symptoms in common cold. Methods Based on randoming and multi-central clinical trial principle, the included 276 c...Objective To probe into the effective acupuncture treatment for high fever and other clinical relevant symptoms in common cold. Methods Based on randoming and multi-central clinical trial principle, the included 276 cases were randomized into experimental group （138 cases） and control group （138 cases） in statistics. Electric acupuncture on Dazhui（大椎 GV14） was applied in experimental group and the injection with antondine was in control group. The immediate antipyretic and clinical therapeutic effects were observed in 24 h. Results The body temperatures at different times in experimental group were all lower than those in control group after treatment （P〈 0.01 ）. The scores of relevant symptoms in 3- 24 h after treatment were lower than those in control group （P〈0.05）. The response time （1.42± 1.79） h in experimental group was shorter than that （3.44±5.10） h in control group （P〈0.05）. The response times for chills, soreness of limbs, headach and sweating in experimental group were shorter than those in control group （P〈0. 01 ）. The recovery times for chills and headache in experimental group were shorter than those in control group （P〈0.05）. The systematic therapeutic effects were different significantly between two groups in 24 h （P〈0.05）. Conclusion Acupuncture on Dazhui（大椎 GV14） had achieved definite effects on treatment for high fever in common cold. It released remarkably chills, soreness of limbs, headache and sweating and improved the systematic therapeutic effects on common cold.展开更多
Soil aggregate stability,as an important indicator of soil functions,may be affected by seasonal freezing and thawing(SFT)and land use in high cold and wet regions.Therefore,comprehensive understanding the effects of ...Soil aggregate stability,as an important indicator of soil functions,may be affected by seasonal freezing and thawing(SFT)and land use in high cold and wet regions.Therefore,comprehensive understanding the effects of SFT on aggregate stability in orchards during winter and spring is crucial to develop appropriate management strategies that can effectively alleviate the degradation of soil quality to ensure sustainable development of orchard ecosystems.To determine the mechanism of degradation in orchard soil quality,the effects of SFT on the stability of water-stable aggregates were examined in apple-pear orchards(Pyrus ussuriensis var.ovoidea)of four different ages(11,25,40,and 63 yr)on 0 to 5%slopes before freezing and after thawing from October 2015 to June 2016 in Longjing City,Yanbian Prefecture,Northeast China,involving a comparison of planted versus adjacent uncultivated lands(control).Soil samples were collected to investigate water-stable aggregate stability in three incremental soil layers(0–20,20–40 and 40–60 cm).In the same samples,iron oxide,organic matter,and clay contents of the soil were also determined.Results showed that the destructive influences of SFT on water-stable aggregates were more pronounced with the increased orchards ages,and SFT exerted severe effects on water-stable aggregates of older orchards(40 and 63 yr)than juvenile orchards.Undergoing SFT,the soil instability index and the percentage of aggregate destruction increased by mean 0.15 mm and 1.86%,the degree of aggregation decreased by mean 1.32%,and the erosion resistance weakened,which consequently led to aggregate stability decreased.In addition,soil free,amorphous,and crystalline iron oxide as well as soil organic matter and clay contents are all important factors affecting the stability of water-stable aggregates,and their changes in their contents were consistent with those in the stability of water-stable aggregates.The results of this study suggest that long-term planting fruit trees can exacerbate the damaging effects of SFT on aggregate stability and further soil erosion increases and nutrient losses in an orchard,which hider sustainable use of soil and the productivity orchards.展开更多
To better understand the relationship between anticyclones in Siberia and cold-air activities and temperature changes in East Asia,this study proposes a 2D anticyclone identification method based on a deep-learning mo...To better understand the relationship between anticyclones in Siberia and cold-air activities and temperature changes in East Asia,this study proposes a 2D anticyclone identification method based on a deep-learning model,Mask R-CNN,which can reliably detect the changes in the morphological characteristics of anticyclones.Using the new method,the authors identified the southeastward-extending Siberian cold high(SEESCH),which greatly affects wintertime temperatures in China.This type of cold high is one of the main synoptic systems(45.7%)emerging from Siberia in winter.Cold air carried by SEESCH has a significant negative correlation with the temperature changes in the downstream area,and 52% of SEESCHs are accompanied by cold-air accumulation in North and East China,which has a significant impact on regional cooling.These results provide clues for studying the interconnection between SEESCHs and extreme cold events.展开更多
The tensile strength and ductility of a high nitrogen nickel-free austenitic stainless steel with solution and cold rolling treatment were investigated by performing tensile tests at different strain rates and at room...The tensile strength and ductility of a high nitrogen nickel-free austenitic stainless steel with solution and cold rolling treatment were investigated by performing tensile tests at different strain rates and at room temperature. The tensile tests demonstrated that this steel exhibits a significant strain rate and cold rolling dependence of the tensile strength and ductility.With the increase of the strain rate from 10^-4s^-1to 1 s^-1, the yield strength and ultimate tensile strength increase and the uniform elongation and total elongation decrease. The analysis of the double logarithmic stress–strain curves showed that this steel exhibits a two-stage strain hardening behavior, which can be well examined and analyzed by using the Ludwigson equation. The strain hardening exponents at low and high strain regions（n2and n1） and the transition strain（εL） decrease with increasing strain rate and the increase of cold rolling RA. Based on the analysis results of the stress–strain curves, the transmission electron microscopy characterization of the microstructure and the scanning electron microscopy observation of the deformation surfaces, the significant strain rate and cold rolling dependence of the strength and ductility of this steel were discussed and connected with the variation in the work hardening and dislocation activity with strain rate and cold rolling.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
The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigate...The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.展开更多
Based on the conventional high-and low-altitude and surface observation data,the weather analysis and diagnosis methods were applied to analyze the cold wave process of Ulanqab in January 2016 from the aspects of weat...Based on the conventional high-and low-altitude and surface observation data,the weather analysis and diagnosis methods were applied to analyze the cold wave process of Ulanqab in January 2016 from the aspects of weather reality,circulation background,weather causes,and forecast test.The results show that strong cold air accumulated gradually near Lake Baikal and Central Siberia,affecting the city in a northwest path.During the cold wave process,the transverse trough moved southwards slowly at 500 hPa,and the ground cold high pressure was strong and stable.The cold air continued to move southwards,resulting in the strong cold wave and gale weather with a large impact range and long duration.The high-altitude jet at 300 hPa strengthened the cold wave pile,which was conducive to the outbreak of the cold wave.The intensity and location changes of the 500 hPa positive vorticity center,850 hPa cold advection region and 24-h ground pressure variation well showed the intensity of the cold wave process and the variation of the affected region.The influence of strong cold advection,ground positive pressure variation,and strong vertical wind shear were the main reasons for a strong drop in temperature and gale weather in this process.The test results of prediction reveal that the forecast value of the maximum temperature were relatively lower than the actual value,while the forecast of the minimum temperature was more accurate.The three warning signals were issued timely and accurately.The circulation pattern predicted by numerical models was more accurate in the early stage of the process,but there was an error in the late stage,and the forecast system moved slower than the actual situation.展开更多
We present a cold atom system with a dark-line two-dimensional magneto-optical trap, to increase the atomic density by suppressing the atomic radiation pressure. Optical depth （OD） and duty cycle are used to evaluat...We present a cold atom system with a dark-line two-dimensional magneto-optical trap, to increase the atomic density by suppressing the atomic radiation pressure. Optical depth （OD） and duty cycle are used to evaluate the system performance. We demonstrate a 100% increase in OD with the dark line, and obtain an ultrahigh OD of 264 with 10% for the duty cycle. Also, with an efficient dark line region, the OD could maintain above i00 with duty cycle as high as 30%. The cold atomic ensemble with an ultrahigh OD with a 10%-30% duty cycle is particularly advantageous in quantum i^formation processing and communication.展开更多
Electrification of vehicles intensifies their cooling demands due to the requirements of maintaining electronics/electrical systems below their maximum temperature threshold.In this paper,passive cooling approaches ba...Electrification of vehicles intensifies their cooling demands due to the requirements of maintaining electronics/electrical systems below their maximum temperature threshold.In this paper,passive cooling approaches based on heat pipes have been considered for the thermal management of electric vehicle(EV)traction systems including battery,inverter,and motor.For the battery,a heat pipe base plate is used to provide high heat removal(180 W per module)and better thermal uniformity(<5°C)for the battery modules in a pack while downsizing the liquid cold plate system.In the case of Inverter,two phase cooling system based on heat pipes was designed to handle hot spots arising from high heat flux(∼100 W/cm2)–for liquid cooling and provide location independence and a dedicated cooling approach-for air cooling.For EV motors,heat pipebased systems are explored for stator and rotor cooling.The paper also provides a glimpse of development on high-performance microchannel-based cold plate technologies based on parallel fins and multi-layer 3D stacked structures.Specifically,this work extends the concept of hybridization of two-phase technology based on heat pipes with single-phase technology,predominately based on liquid cooling,to extend performance,functionalities,and operational regime of cooling solutions for components of EV drive trains.In summary,heat pipes will help to improve and extend the overall reliability,performance,and safety of air and liquid cooling systems in electric vehicles.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 Huanghai Sea (HS) and northern East Chin...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 Huanghai 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 core at Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy between these two northward flows, and a weak cyclonic eddy at the western part of Section PN. The above current structure is one type of the current structures at Section PN in ECS. The net northward volume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB) through Section PN is about 26.2 x 10(6) m(3)/s in June 1999. The VT of the inshore branch of Taiwan Warm Current (TWCIB) through the investigated region is about 0.4 x 10(6) m(3)/s. The Taiwan Warm Current (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea Coastal Current (HSCC) flows southeastward and enters into the northwestern part of investigated region, and flows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan Warm Current and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea Coastal Current flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and cold water is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 at the northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).展开更多
Salmonellosis outbreaks caused by Salmonella Enteritidis are usually linked to the consumption of eggs and egg products.To assure egg safety,High Voltage Atmospheric Cold Plasma(HVACP)has demonstrated its efficacy in ...Salmonellosis outbreaks caused by Salmonella Enteritidis are usually linked to the consumption of eggs and egg products.To assure egg safety,High Voltage Atmospheric Cold Plasma(HVACP)has demonstrated its efficacy in achieving higher than 105 CFU/egg reduction of this bacteria on the egg’s surface.Although no quality changes were found immediately after treatment,there was a lack of knowledge on how the quality of HVACP-treated eggs could evolve during their shelf life,and a six-week quality study was performed in this work.Eggs were treated under two sets of conditions,0.5 min of treatment within 24 h post treatment and 8.5 min of treatment and no post treatment time were the selected ones.No significant differences were found between untreated and treated eggs regarding albumen and yolk pH,Haugh unit,yolk color,vitelline membrane strength or shell strength.The changes detected during the six weeks of storage at 4℃ were attributed to the natural aging of the eggs and not to the effect of HVACP treatments.These results prove HVACP technology as an effective alternative to current techniques to assure both the safety and quality of eggs during their shelf life.展开更多
Landscape elements in residential areas can effectively improve the outdoor thermal environment,with different outcomes depending on the climate conditions.This study explores how the ground surface and shading proper...Landscape elements in residential areas can effectively improve the outdoor thermal environment,with different outcomes depending on the climate conditions.This study explores how the ground surface and shading properties affect the outdoor thermal environment in a high-altitude plateau climate where few studies have been conducted.The measurements were conducted during summer and winter in a residential area in Lhasa,Tibet.Without natural shading such as trees,there is a positive correlation between Sky-view factor(SVF)and Physiological equivalent temperature(PET)during winter and a negative correlation during summer.When SVF exceeds 0.65 in summer,it may cause human discomfort.Compared to artificial shading such as a tensioned membrane,deciduous trees are superior at improving human comfort,as they can increase PET by 10.56℃ in winter and decrease it by 9.73℃ in summer.During summer,high-reflection water-permeable bricks can reduce the PET by 1.08℃,and lawns can reduce the mean rachation temperature(Tmrt)by 1.650C;however,the lawns may produce a microclimate with a high air temperature.The results from this paper can be used as a reference for landscape planning and design in residential areas in high-altitude cold-climate regions.展开更多
文摘Objective To probe into the effective acupuncture treatment for high fever and other clinical relevant symptoms in common cold. Methods Based on randoming and multi-central clinical trial principle, the included 276 cases were randomized into experimental group （138 cases） and control group （138 cases） in statistics. Electric acupuncture on Dazhui（大椎 GV14） was applied in experimental group and the injection with antondine was in control group. The immediate antipyretic and clinical therapeutic effects were observed in 24 h. Results The body temperatures at different times in experimental group were all lower than those in control group after treatment （P〈 0.01 ）. The scores of relevant symptoms in 3- 24 h after treatment were lower than those in control group （P〈0.05）. The response time （1.42± 1.79） h in experimental group was shorter than that （3.44±5.10） h in control group （P〈0.05）. The response times for chills, soreness of limbs, headach and sweating in experimental group were shorter than those in control group （P〈0. 01 ）. The recovery times for chills and headache in experimental group were shorter than those in control group （P〈0.05）. The systematic therapeutic effects were different significantly between two groups in 24 h （P〈0.05）. Conclusion Acupuncture on Dazhui（大椎 GV14） had achieved definite effects on treatment for high fever in common cold. It released remarkably chills, soreness of limbs, headache and sweating and improved the systematic therapeutic effects on common cold.
基金Under the auspices of National Natural Science Foundation of China(No.31460117,41877024)。
文摘Soil aggregate stability,as an important indicator of soil functions,may be affected by seasonal freezing and thawing(SFT)and land use in high cold and wet regions.Therefore,comprehensive understanding the effects of SFT on aggregate stability in orchards during winter and spring is crucial to develop appropriate management strategies that can effectively alleviate the degradation of soil quality to ensure sustainable development of orchard ecosystems.To determine the mechanism of degradation in orchard soil quality,the effects of SFT on the stability of water-stable aggregates were examined in apple-pear orchards(Pyrus ussuriensis var.ovoidea)of four different ages(11,25,40,and 63 yr)on 0 to 5%slopes before freezing and after thawing from October 2015 to June 2016 in Longjing City,Yanbian Prefecture,Northeast China,involving a comparison of planted versus adjacent uncultivated lands(control).Soil samples were collected to investigate water-stable aggregate stability in three incremental soil layers(0–20,20–40 and 40–60 cm).In the same samples,iron oxide,organic matter,and clay contents of the soil were also determined.Results showed that the destructive influences of SFT on water-stable aggregates were more pronounced with the increased orchards ages,and SFT exerted severe effects on water-stable aggregates of older orchards(40 and 63 yr)than juvenile orchards.Undergoing SFT,the soil instability index and the percentage of aggregate destruction increased by mean 0.15 mm and 1.86%,the degree of aggregation decreased by mean 1.32%,and the erosion resistance weakened,which consequently led to aggregate stability decreased.In addition,soil free,amorphous,and crystalline iron oxide as well as soil organic matter and clay contents are all important factors affecting the stability of water-stable aggregates,and their changes in their contents were consistent with those in the stability of water-stable aggregates.The results of this study suggest that long-term planting fruit trees can exacerbate the damaging effects of SFT on aggregate stability and further soil erosion increases and nutrient losses in an orchard,which hider sustainable use of soil and the productivity orchards.
基金supported jointly by the National Key Research and Development Program of China[grant number 2019YFC1510201]the National Natural Science Foundation of China[grant number 41975073].
文摘To better understand the relationship between anticyclones in Siberia and cold-air activities and temperature changes in East Asia,this study proposes a 2D anticyclone identification method based on a deep-learning model,Mask R-CNN,which can reliably detect the changes in the morphological characteristics of anticyclones.Using the new method,the authors identified the southeastward-extending Siberian cold high(SEESCH),which greatly affects wintertime temperatures in China.This type of cold high is one of the main synoptic systems(45.7%)emerging from Siberia in winter.Cold air carried by SEESCH has a significant negative correlation with the temperature changes in the downstream area,and 52% of SEESCHs are accompanied by cold-air accumulation in North and East China,which has a significant impact on regional cooling.These results provide clues for studying the interconnection between SEESCHs and extreme cold events.
基金Project supported by the National Natural Science Foundations of China(Grant Nos.51371089 and 51401083)
文摘The tensile strength and ductility of a high nitrogen nickel-free austenitic stainless steel with solution and cold rolling treatment were investigated by performing tensile tests at different strain rates and at room temperature. The tensile tests demonstrated that this steel exhibits a significant strain rate and cold rolling dependence of the tensile strength and ductility.With the increase of the strain rate from 10^-4s^-1to 1 s^-1, the yield strength and ultimate tensile strength increase and the uniform elongation and total elongation decrease. The analysis of the double logarithmic stress–strain curves showed that this steel exhibits a two-stage strain hardening behavior, which can be well examined and analyzed by using the Ludwigson equation. The strain hardening exponents at low and high strain regions（n2and n1） and the transition strain（εL） decrease with increasing strain rate and the increase of cold rolling RA. Based on the analysis results of the stress–strain curves, the transmission electron microscopy characterization of the microstructure and the scanning electron microscopy observation of the deformation surfaces, the significant strain rate and cold rolling dependence of the strength and ductility of this steel were discussed and connected with the variation in the work hardening and dislocation activity with strain rate and cold rolling.
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The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.
文摘Based on the conventional high-and low-altitude and surface observation data,the weather analysis and diagnosis methods were applied to analyze the cold wave process of Ulanqab in January 2016 from the aspects of weather reality,circulation background,weather causes,and forecast test.The results show that strong cold air accumulated gradually near Lake Baikal and Central Siberia,affecting the city in a northwest path.During the cold wave process,the transverse trough moved southwards slowly at 500 hPa,and the ground cold high pressure was strong and stable.The cold air continued to move southwards,resulting in the strong cold wave and gale weather with a large impact range and long duration.The high-altitude jet at 300 hPa strengthened the cold wave pile,which was conducive to the outbreak of the cold wave.The intensity and location changes of the 500 hPa positive vorticity center,850 hPa cold advection region and 24-h ground pressure variation well showed the intensity of the cold wave process and the variation of the affected region.The influence of strong cold advection,ground positive pressure variation,and strong vertical wind shear were the main reasons for a strong drop in temperature and gale weather in this process.The test results of prediction reveal that the forecast value of the maximum temperature were relatively lower than the actual value,while the forecast of the minimum temperature was more accurate.The three warning signals were issued timely and accurately.The circulation pattern predicted by numerical models was more accurate in the early stage of the process,but there was an error in the late stage,and the forecast system moved slower than the actual situation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91436211 and 11204086the National Basic Research Program of China under Grant No 2011CB921604the Shanghai Science and Technology Committee under Grant No 13PJ1402100
文摘We present a cold atom system with a dark-line two-dimensional magneto-optical trap, to increase the atomic density by suppressing the atomic radiation pressure. Optical depth （OD） and duty cycle are used to evaluate the system performance. We demonstrate a 100% increase in OD with the dark line, and obtain an ultrahigh OD of 264 with 10% for the duty cycle. Also, with an efficient dark line region, the OD could maintain above i00 with duty cycle as high as 30%. The cold atomic ensemble with an ultrahigh OD with a 10%-30% duty cycle is particularly advantageous in quantum i^formation processing and communication.
文摘Electrification of vehicles intensifies their cooling demands due to the requirements of maintaining electronics/electrical systems below their maximum temperature threshold.In this paper,passive cooling approaches based on heat pipes have been considered for the thermal management of electric vehicle(EV)traction systems including battery,inverter,and motor.For the battery,a heat pipe base plate is used to provide high heat removal(180 W per module)and better thermal uniformity(<5°C)for the battery modules in a pack while downsizing the liquid cold plate system.In the case of Inverter,two phase cooling system based on heat pipes was designed to handle hot spots arising from high heat flux(∼100 W/cm2)–for liquid cooling and provide location independence and a dedicated cooling approach-for air cooling.For EV motors,heat pipebased systems are explored for stator and rotor cooling.The paper also provides a glimpse of development on high-performance microchannel-based cold plate technologies based on parallel fins and multi-layer 3D stacked structures.Specifically,this work extends the concept of hybridization of two-phase technology based on heat pipes with single-phase technology,predominately based on liquid cooling,to extend performance,functionalities,and operational regime of cooling solutions for components of EV drive trains.In summary,heat pipes will help to improve and extend the overall reliability,performance,and safety of air and liquid cooling systems in electric vehicles.
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 Huanghai 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 core at Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy between these two northward flows, and a weak cyclonic eddy at the western part of Section PN. The above current structure is one type of the current structures at Section PN in ECS. The net northward volume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB) through Section PN is about 26.2 x 10(6) m(3)/s in June 1999. The VT of the inshore branch of Taiwan Warm Current (TWCIB) through the investigated region is about 0.4 x 10(6) m(3)/s. The Taiwan Warm Current (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea Coastal Current (HSCC) flows southeastward and enters into the northwestern part of investigated region, and flows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan Warm Current and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea Coastal Current flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and cold water is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 at the northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).
基金supported by Ontario Ministry of Agriculture,Food and Rural Affairs(OMAFRA)he Barrett Family Foundation Chair in Sustainable Food Engineering.
文摘Salmonellosis outbreaks caused by Salmonella Enteritidis are usually linked to the consumption of eggs and egg products.To assure egg safety,High Voltage Atmospheric Cold Plasma(HVACP)has demonstrated its efficacy in achieving higher than 105 CFU/egg reduction of this bacteria on the egg’s surface.Although no quality changes were found immediately after treatment,there was a lack of knowledge on how the quality of HVACP-treated eggs could evolve during their shelf life,and a six-week quality study was performed in this work.Eggs were treated under two sets of conditions,0.5 min of treatment within 24 h post treatment and 8.5 min of treatment and no post treatment time were the selected ones.No significant differences were found between untreated and treated eggs regarding albumen and yolk pH,Haugh unit,yolk color,vitelline membrane strength or shell strength.The changes detected during the six weeks of storage at 4℃ were attributed to the natural aging of the eggs and not to the effect of HVACP treatments.These results prove HVACP technology as an effective alternative to current techniques to assure both the safety and quality of eggs during their shelf life.
文摘Landscape elements in residential areas can effectively improve the outdoor thermal environment,with different outcomes depending on the climate conditions.This study explores how the ground surface and shading properties affect the outdoor thermal environment in a high-altitude plateau climate where few studies have been conducted.The measurements were conducted during summer and winter in a residential area in Lhasa,Tibet.Without natural shading such as trees,there is a positive correlation between Sky-view factor(SVF)and Physiological equivalent temperature(PET)during winter and a negative correlation during summer.When SVF exceeds 0.65 in summer,it may cause human discomfort.Compared to artificial shading such as a tensioned membrane,deciduous trees are superior at improving human comfort,as they can increase PET by 10.56℃ in winter and decrease it by 9.73℃ in summer.During summer,high-reflection water-permeable bricks can reduce the PET by 1.08℃,and lawns can reduce the mean rachation temperature(Tmrt)by 1.650C;however,the lawns may produce a microclimate with a high air temperature.The results from this paper can be used as a reference for landscape planning and design in residential areas in high-altitude cold-climate regions.
