Seamless transportation of goods seems to be the inevitable trend for the modern logistics industry. Logistics is currently making a transition to multimodal transport from the single-mode.
On February 12,the Anhui ProvincialPeople’s Government made a decisionon the speeding up of the use of foreigncapital.The decision involved the followingseven aspects: 1.To seize the opportunity to reviseideology and...On February 12,the Anhui ProvincialPeople’s Government made a decisionon the speeding up of the use of foreigncapital.The decision involved the followingseven aspects: 1.To seize the opportunity to reviseideology and to open up a new situation formaking use of foreign capital.The decisionurges the various localities to seize the righttime to shift their focus to making good useof their own advantages,and improving thelocal investment climate and the quality ofservice in the light of their actual conditionsso as to absorb more foreign funds.Meanwhile,enterprises must be led to face the marketand to join equal competition so as to pushforward the use of foreign funds to a展开更多
The 1990s is a key historical decade in the process of China’s on-going modernization drive.When reviewing the overall picture of the socio-economic trend and S&T development around the world during the last two ...The 1990s is a key historical decade in the process of China’s on-going modernization drive.When reviewing the overall picture of the socio-economic trend and S&T development around the world during the last two decades,we may reach the conclusion that a new technological revolution is taking shape.For both the developed and the developing countries,challenges and opportunities are close at hand.In the Decision to Speed up China’s S&T Progress Jointly Issued by the CPC Central Committee and the State Council.a developmen-展开更多
1.The Current Situation
Facing China's accession to the WTO,our pharmaceutical industries must prepare to meet extremely strong competition,because 97% of the synthetic medicines and antibiotics marketed in the co...1.The Current Situation
Facing China's accession to the WTO,our pharmaceutical industries must prepare to meet extremely strong competition,because 97% of the synthetic medicines and antibiotics marketed in the country are copies of foreign products.展开更多
In the human body, the number of cells is tightlyre gulated. When cells are no longer needed, they commit suicide through a programmed cell death,called apoptosis. Massive amount of cell apoptosis takes place in devel...In the human body, the number of cells is tightlyre gulated. When cells are no longer needed, they commit suicide through a programmed cell death,called apoptosis. Massive amount of cell apoptosis takes place in developing tissues and even adult bodies.展开更多
shipbuilding in recent years.In order to maintain the shipbuilding technology"super gap"which its shipbuilding industry is proud of,South Korea has introduced AI tech not only in the design stage,hut also in...shipbuilding in recent years.In order to maintain the shipbuilding technology"super gap"which its shipbuilding industry is proud of,South Korea has introduced AI tech not only in the design stage,hut also in the construction stage.展开更多
Previous studies have indicated a global reversal of near-surface wind speeds from a declining trend to an increasing trend around 2010;however,it remains unclear whether upper-air wind speeds exhibit a similar revers...Previous studies have indicated a global reversal of near-surface wind speeds from a declining trend to an increasing trend around 2010;however,it remains unclear whether upper-air wind speeds exhibit a similar reversal.This study evaluates reanalysis products using surface and radiosonde observations to analyze upper-air wind speed variations in the Northern Hemisphere,focusing on their seasonal and latitudinal differences.Results demonstrate that JRA-55 effectively captures wind speed variations in the Northern Hemisphere.Notably,upper-air wind speeds over land experienced a reversal in winter 2010 with significant latitudinal differences.The trend reversal of upper wind speed between the midlatitudes and subtropics presents a dipole pattern.From 1990 to 2010,upper-air wind speeds in the midlatitudes(40°-70°N)significantly declined,while the subtropical zone(20°-40°N)displayed an opposite trend.However,during 2010-2020,wind speeds in the midlatitudes shifted to a significant positive trend,whereas the subtropics experienced a significant negative trend.The variations in Northern Hemisphere winter wind speeds can be attributed to changes in low-level baroclinicity driven by tropical diabatic heating and midlatitude transient eddy feedback.Enhanced diabatic heating and weakened eddy feedback during 1990-2010 contributed to reduced wind speeds in the midlatitudes and increased speeds in the subtropics,while reduced diabatic heating and strengthened eddy feedback during 2010-2020 resulted in increased wind speeds in the midlatitudes and decreased speeds in the subtropics.The reversal of upper-air wind speeds could affect surface wind speeds by downward momentum transfer,which could contribute to the reversal of surface wind speeds.展开更多
By applying the convolution-based Hilbert transform in the zonal direction on six-hourly streamfunction fields at200 h Pa, we present the climatology and trends of the local wave period, and zonal and meridional phase...By applying the convolution-based Hilbert transform in the zonal direction on six-hourly streamfunction fields at200 h Pa, we present the climatology and trends of the local wave period, and zonal and meridional phase speeds, of Rossby waves over the globe during the solstice seasons of 1979–2023. While partly similar to and inspired by Fragkoulidis and Wirth(2020), our method differs in its ability to cover both planetary-scale and synoptic-scale waves over not only the extratropics, but also the tropics and subtropics. Based on a physically reasonable global distribution of wave periods, our key new finding is a robust prolonging of wave periods over most regions of the tropics and subtropics during both solstice seasons of 1979–2023, except for the tropical Atlantic, which experiences a shortened wave period during June–July–August of 1979–2022. Both the prolonging and shortening of wave periods are mainly associated with the changes in planetary-scale waves. Regionally varying trends of the zonal phase speed(Cpx) of synoptic waves are consistent in sign with, but smaller in magnitude than, the trends of local zonal wind, confirming the conclusion of Wu and Lu(2023)on the opposite effects of zonal wind and the meridional gradient of potential vorticity on Cpx. Meanwhile, the Cpx trends of planetary-scale waves are relatively weak, and do not exhibit a robust relation with the trend of zonal wind. These new results are helpful toward better understanding the changes in atmospheric waves and extreme events under global warming.展开更多
The high-speed reentry vehicle operates across a broad range of speeds and spatial domains,where optimal aerodynamic shapes for different speeds are contradictory.This makes it challenging for a single-Mach optimizati...The high-speed reentry vehicle operates across a broad range of speeds and spatial domains,where optimal aerodynamic shapes for different speeds are contradictory.This makes it challenging for a single-Mach optimization design to meet aerodynamic performance requirements throughout the vehicle’s flight envelope.Additionally,the strong coupling between aerodynamics and control adds complexity,as fluctuations in aerodynamic parameters due to speed variations complicate control system design.To address these challenges,this study proposes an aerodynamic/control coupling optimization design approach.This method,based on aerodynamic optimization principles,incorporates active control technology,treating aerodynamic layout and control system design as primary components during the conceptual design phase.By integrating the design and evaluation of aerodynamics and control,the approach aims to reduce design iterations and enhance overall flight performance.The comprehensive design of the rotary reentry vehicle,using this optimization strategy,effectively balances performance at supersonic and hypersonic speeds.The results show that the integrated design model meets aerodynamic and control performance requirements over a broader range of Mach numbers,preventing performance degradation due to deviations from the design Mach number,and providing a practical solution for high-speed reentry vehicle design.展开更多
LEADSFON(XIAMEN)TEXTILE TECH CO.,LTD.is a manufacturer of knitting circular machines.Since 2002,the company has served as an ODM and supporting partner for the Italian brand"PILOTELLI".In 2014,LEADSFON offic...LEADSFON(XIAMEN)TEXTILE TECH CO.,LTD.is a manufacturer of knitting circular machines.Since 2002,the company has served as an ODM and supporting partner for the Italian brand"PILOTELLI".In 2014,LEADSFON officially acquired PILOTELLI,integrating advanced Italian technology into its core operations.展开更多
Chinese authorities have introduced a speed limit for new electric mopeds and banned sales of older models in the name of safety.Delivery riders worry the changes will cut the number of orders they can complete each d...Chinese authorities have introduced a speed limit for new electric mopeds and banned sales of older models in the name of safety.Delivery riders worry the changes will cut the number of orders they can complete each day,and their incomes By Wahg Shihan and Xie Ying.展开更多
Safer,smarter,faster...In China,people prefer high-speed trains to flights if the journey time is under five hours.High-speed train travel is set to become even more attractive with the addition of a new member to the...Safer,smarter,faster...In China,people prefer high-speed trains to flights if the journey time is under five hours.High-speed train travel is set to become even more attractive with the addition of a new member to the high-speed train family:the CR450,the world’s fastest electric multiple unit(EMU).展开更多
Convolutional Neural Networks(CNN)have achieved great success in many computer vision tasks.However,it is difficult to deploy CNN models on low-cost devices with limited power budgets,because most existing CNN models ...Convolutional Neural Networks(CNN)have achieved great success in many computer vision tasks.However,it is difficult to deploy CNN models on low-cost devices with limited power budgets,because most existing CNN models are computationally expensive.Therefore,CNN model compression and acceleration have become a hot research topic in the deep learning area.Typical schemes for speeding up the feed-forward process with a slight accuracy loss include parameter pruning and sharing,low-rank factorization,compact convolutional filters and knowledge distillation.In this study,we propose a general acceleration scheme that replaces the floating-point multiplication with integer addition.To this end,we propose a general accelerate scheme,where the floating point multiplication is replaced by integer addition.The motivation is based on the fact that every floating point can be replaced by the summation of an exponential series.Therefore,the multiplication between two floating points can be converted to the addition among exponentials.In the experiment section,we directly apply the proposed scheme to AlexNet,VGG,ResNet for image classification,and Faster-RCNN for object detection.The results acquired from ImageNet and PASCAL VOC show that the proposed quantized scheme has a promising performance,even with only one item of exponential.Moreover,we analyzed the eciency of our method on mainstream FPGAs.The experimental results show that the proposed quantized scheme can achieve acceleration on FPGA with a slight accuracy loss.展开更多
Infrastructure systems play a fundamental role in reducing greenhouse gas(GHG)emissions to avert global climate change(Kennedy et al.,2014).Transportations are recognized as one of the key factors for facilitating cli...Infrastructure systems play a fundamental role in reducing greenhouse gas(GHG)emissions to avert global climate change(Kennedy et al.,2014).Transportations are recognized as one of the key factors for facilitating climate change mitigation(Shaw et al.,2014).Approximately 19%of global energy consumption and 23%of energy-related carbon dioxide(CO2)emissions come from the transportation sector(IEA,2012).The demands are still increasing at an annual average rate of 1.4%(EIA,2016).Scholars展开更多
文摘Seamless transportation of goods seems to be the inevitable trend for the modern logistics industry. Logistics is currently making a transition to multimodal transport from the single-mode.
文摘On February 12,the Anhui ProvincialPeople’s Government made a decisionon the speeding up of the use of foreigncapital.The decision involved the followingseven aspects: 1.To seize the opportunity to reviseideology and to open up a new situation formaking use of foreign capital.The decisionurges the various localities to seize the righttime to shift their focus to making good useof their own advantages,and improving thelocal investment climate and the quality ofservice in the light of their actual conditionsso as to absorb more foreign funds.Meanwhile,enterprises must be led to face the marketand to join equal competition so as to pushforward the use of foreign funds to a
文摘The 1990s is a key historical decade in the process of China’s on-going modernization drive.When reviewing the overall picture of the socio-economic trend and S&T development around the world during the last two decades,we may reach the conclusion that a new technological revolution is taking shape.For both the developed and the developing countries,challenges and opportunities are close at hand.In the Decision to Speed up China’s S&T Progress Jointly Issued by the CPC Central Committee and the State Council.a developmen-
文摘1.The Current Situation
Facing China's accession to the WTO,our pharmaceutical industries must prepare to meet extremely strong competition,because 97% of the synthetic medicines and antibiotics marketed in the country are copies of foreign products.
基金supported by the National Natural Science Foundation of Chinathe Ministry of Science and Technology of ChinaCAS
文摘In the human body, the number of cells is tightlyre gulated. When cells are no longer needed, they commit suicide through a programmed cell death,called apoptosis. Massive amount of cell apoptosis takes place in developing tissues and even adult bodies.
文摘shipbuilding in recent years.In order to maintain the shipbuilding technology"super gap"which its shipbuilding industry is proud of,South Korea has introduced AI tech not only in the design stage,hut also in the construction stage.
基金supported by the National Natural Science Foundation of China[grant numbers U2442207,42122034,42075043,and 42330609]the Youth Innovation Promotion Association[grant number 2021427]+2 种基金the West Light Foundation[grant number xbzgzdsys-202409]of the Chinese Academy of Sciencesthe Key Talent Projects in Gansu Provincethe Central Guidance Fund for Local Science and Technology Development Projects in Gansu Province[grant number 24ZYQA031].
文摘Previous studies have indicated a global reversal of near-surface wind speeds from a declining trend to an increasing trend around 2010;however,it remains unclear whether upper-air wind speeds exhibit a similar reversal.This study evaluates reanalysis products using surface and radiosonde observations to analyze upper-air wind speed variations in the Northern Hemisphere,focusing on their seasonal and latitudinal differences.Results demonstrate that JRA-55 effectively captures wind speed variations in the Northern Hemisphere.Notably,upper-air wind speeds over land experienced a reversal in winter 2010 with significant latitudinal differences.The trend reversal of upper wind speed between the midlatitudes and subtropics presents a dipole pattern.From 1990 to 2010,upper-air wind speeds in the midlatitudes(40°-70°N)significantly declined,while the subtropical zone(20°-40°N)displayed an opposite trend.However,during 2010-2020,wind speeds in the midlatitudes shifted to a significant positive trend,whereas the subtropics experienced a significant negative trend.The variations in Northern Hemisphere winter wind speeds can be attributed to changes in low-level baroclinicity driven by tropical diabatic heating and midlatitude transient eddy feedback.Enhanced diabatic heating and weakened eddy feedback during 1990-2010 contributed to reduced wind speeds in the midlatitudes and increased speeds in the subtropics,while reduced diabatic heating and strengthened eddy feedback during 2010-2020 resulted in increased wind speeds in the midlatitudes and decreased speeds in the subtropics.The reversal of upper-air wind speeds could affect surface wind speeds by downward momentum transfer,which could contribute to the reversal of surface wind speeds.
基金the support from the National Natural Science Foundation of China (Grant No. 42175070)supported by the National Natural Science Foundation of China (Grant No. 42288101)supported by the National Key Scientific and Technological Infrastructure project “Earth System Numerical Simulation Facility” (Earth Lab)。
文摘By applying the convolution-based Hilbert transform in the zonal direction on six-hourly streamfunction fields at200 h Pa, we present the climatology and trends of the local wave period, and zonal and meridional phase speeds, of Rossby waves over the globe during the solstice seasons of 1979–2023. While partly similar to and inspired by Fragkoulidis and Wirth(2020), our method differs in its ability to cover both planetary-scale and synoptic-scale waves over not only the extratropics, but also the tropics and subtropics. Based on a physically reasonable global distribution of wave periods, our key new finding is a robust prolonging of wave periods over most regions of the tropics and subtropics during both solstice seasons of 1979–2023, except for the tropical Atlantic, which experiences a shortened wave period during June–July–August of 1979–2022. Both the prolonging and shortening of wave periods are mainly associated with the changes in planetary-scale waves. Regionally varying trends of the zonal phase speed(Cpx) of synoptic waves are consistent in sign with, but smaller in magnitude than, the trends of local zonal wind, confirming the conclusion of Wu and Lu(2023)on the opposite effects of zonal wind and the meridional gradient of potential vorticity on Cpx. Meanwhile, the Cpx trends of planetary-scale waves are relatively weak, and do not exhibit a robust relation with the trend of zonal wind. These new results are helpful toward better understanding the changes in atmospheric waves and extreme events under global warming.
基金supported by the National Natural Science Foundation of China(Grant Nos.52192633,92371201,11872293,and 92152301)the Natural Science Foundation of Shaanxi Province(Grant No.2022JC-03).
文摘The high-speed reentry vehicle operates across a broad range of speeds and spatial domains,where optimal aerodynamic shapes for different speeds are contradictory.This makes it challenging for a single-Mach optimization design to meet aerodynamic performance requirements throughout the vehicle’s flight envelope.Additionally,the strong coupling between aerodynamics and control adds complexity,as fluctuations in aerodynamic parameters due to speed variations complicate control system design.To address these challenges,this study proposes an aerodynamic/control coupling optimization design approach.This method,based on aerodynamic optimization principles,incorporates active control technology,treating aerodynamic layout and control system design as primary components during the conceptual design phase.By integrating the design and evaluation of aerodynamics and control,the approach aims to reduce design iterations and enhance overall flight performance.The comprehensive design of the rotary reentry vehicle,using this optimization strategy,effectively balances performance at supersonic and hypersonic speeds.The results show that the integrated design model meets aerodynamic and control performance requirements over a broader range of Mach numbers,preventing performance degradation due to deviations from the design Mach number,and providing a practical solution for high-speed reentry vehicle design.
文摘LEADSFON(XIAMEN)TEXTILE TECH CO.,LTD.is a manufacturer of knitting circular machines.Since 2002,the company has served as an ODM and supporting partner for the Italian brand"PILOTELLI".In 2014,LEADSFON officially acquired PILOTELLI,integrating advanced Italian technology into its core operations.
文摘Chinese authorities have introduced a speed limit for new electric mopeds and banned sales of older models in the name of safety.Delivery riders worry the changes will cut the number of orders they can complete each day,and their incomes By Wahg Shihan and Xie Ying.
文摘Safer,smarter,faster...In China,people prefer high-speed trains to flights if the journey time is under five hours.High-speed train travel is set to become even more attractive with the addition of a new member to the high-speed train family:the CR450,the world’s fastest electric multiple unit(EMU).
基金the National Natural Science Foundation of China(Grant Nos.41971424,61701191)the Key Technical Project of Xiamen Ocean Bureau(Grant No.18CZB033HJ11)+2 种基金the Natural Science Foundation of Fujian Province(Grant Nos.2019J01712,2020J01701)the Key Technical Project of Xiamen Science and Technology Bureau(Grant Nos.3502Z20191018,3502Z20201007,3502Z20191022,3502Z20203057)the Science and Technology Project of Education Department of Fujian Province(Grant Nos.JAT190321,JAT190318,JAT190315)。
文摘Convolutional Neural Networks(CNN)have achieved great success in many computer vision tasks.However,it is difficult to deploy CNN models on low-cost devices with limited power budgets,because most existing CNN models are computationally expensive.Therefore,CNN model compression and acceleration have become a hot research topic in the deep learning area.Typical schemes for speeding up the feed-forward process with a slight accuracy loss include parameter pruning and sharing,low-rank factorization,compact convolutional filters and knowledge distillation.In this study,we propose a general acceleration scheme that replaces the floating-point multiplication with integer addition.To this end,we propose a general accelerate scheme,where the floating point multiplication is replaced by integer addition.The motivation is based on the fact that every floating point can be replaced by the summation of an exponential series.Therefore,the multiplication between two floating points can be converted to the addition among exponentials.In the experiment section,we directly apply the proposed scheme to AlexNet,VGG,ResNet for image classification,and Faster-RCNN for object detection.The results acquired from ImageNet and PASCAL VOC show that the proposed quantized scheme has a promising performance,even with only one item of exponential.Moreover,we analyzed the eciency of our method on mainstream FPGAs.The experimental results show that the proposed quantized scheme can achieve acceleration on FPGA with a slight accuracy loss.
基金supported by the National Natural Science Foundation of China (Grant No.71390525)
文摘Infrastructure systems play a fundamental role in reducing greenhouse gas(GHG)emissions to avert global climate change(Kennedy et al.,2014).Transportations are recognized as one of the key factors for facilitating climate change mitigation(Shaw et al.,2014).Approximately 19%of global energy consumption and 23%of energy-related carbon dioxide(CO2)emissions come from the transportation sector(IEA,2012).The demands are still increasing at an annual average rate of 1.4%(EIA,2016).Scholars
