As a major function of smart transportation in smart cities,vehicle model recognition plays an important role in intelligent transportation.Due to the difference among different vehicle models recognition datasets,the...As a major function of smart transportation in smart cities,vehicle model recognition plays an important role in intelligent transportation.Due to the difference among different vehicle models recognition datasets,the accuracy of network model training in one scene will be greatly reduced in another one.However,if you don’t have a lot of vehicle model datasets for the current scene,you cannot properly train a model.To address this problem,we study the problem of cold start of vehicle model recognition under cross-scenario.Under the condition of small amount of datasets,combined with the method of transfer learning,load the DAN(Deep Adaptation Networks)and JAN(Joint Adaptation Networks)domain adaptation modules into the convolutional neural network AlexNet and ResNet,and get four models:AlexNet-JAN,AlexNet-DAN,ResNet-JAN,and ResNet-DAN which can achieve a higher accuracy at the beginning.Through experiments,transfer the vehicle model recognition from the network image dataset(source domain)to the surveillance-nature dataset(target domain),both Top-1 and Top-5 accuracy have been improved by at least 20%.展开更多
[Objectives] To determine the nine phenolic components in the leaves of Crataegus pinnatifida Bge. [Methods] The reversedphase high-performance liquid chromatography( RP-HPLC) was applied. [Results] Nine phenolic comp...[Objectives] To determine the nine phenolic components in the leaves of Crataegus pinnatifida Bge. [Methods] The reversedphase high-performance liquid chromatography( RP-HPLC) was applied. [Results] Nine phenolic components showed a good linear relationship in the range of 2-500 μg/m L with r in the range of 0. 999 5-0. 999 9. The recovery rate of spiked samples ranged from 93. 7% to110. 2%,and the relative standard deviation was in the range of 0. 69%-4. 58%. The leaves of 29 cultivars of C. pinnatifida Bge. were measured,and the average content of the nine phenolic components was as follows: isoquercitrin,hyperoside,procyanidin C1,procyanidin D1,epicatechin,procyanidin B2,chlorogenic acid,eucomic acid,and vitexin 2 "-O-rhamnoside. The contents of flavonoids and phenolic acids were high,up to 15 mg/g D. W,and the content of procyanidins was up to 6 mg/g D. W. [Conclusions]This method is easy and accurate in determination of phenolic components in the leaves of C. pinnatifida Bge.展开更多
Window opening behavior significantly impacts indoor air quality,thermal comfort,and energy consumption.A field measurement was carried out in three typical rooms(a standard office,a meeting room and a smoking office)...Window opening behavior significantly impacts indoor air quality,thermal comfort,and energy consumption.A field measurement was carried out in three typical rooms(a standard office,a meeting room and a smoking office)within an office building.The window state and the physical environment were continuously recorded during the measured periods.Three typical window opening behaviors were found in the measured samples,namely,active,moderate,and passive.The common logistic regression coefficient indicated that solar radiation exhibited the greatest effect on window opening behavior in the smoking office and standard office.Typically,window opening behavior in the meeting room was the most strongly correlated with time of the day,mainly because of the meeting schedule for occupants in the meeting room.This study discussed the dividing principles involved in setting the dummy variable interval level(discretizing continuous variables and dividing them into different intervals),and proposed a method to determine the optimal interval level of each variable.The improved model led to the increase in the prediction accuracy rate of the window being opened by 2.0%and 3.3%according to the comparison with the original model based on dummy variables and the common model based on continuous variables,respectively.This study can provide a reference value for simulating energy consumption in office buildings in the future.展开更多
With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization tech...With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization techniques aim at achieving the structurally most efficient solution without any potential for architects or designers to control the design details.This paper introduces three strategies based on Bi-directional Evolutionary Structural Optimization(BESO)method to artificially pre-design the topological optimized structures.These strategies have been successfully applied in the computational morphogenesis of various structures for solving practical design problems.The results demonstrate that the developed methodology can provide the designer with structurally efficient and topologically different solutions according to their proposed designs with multi-filter radii,multi-volume fractions,and multi-weighting coefficients.This work establishes a general approach to integrating objective topology optimization methods with subjective human design preferences,which has great potential for practical applications in architecture and engineering industry.展开更多
Seawater electrolysis could address the water scarcity issue and realize the grid-scale production of carbon-neutral hydrogen,while facing the challenge of high energy consumption and chloride corrosion.Thermodynamica...Seawater electrolysis could address the water scarcity issue and realize the grid-scale production of carbon-neutral hydrogen,while facing the challenge of high energy consumption and chloride corrosion.Thermodynamically more favorable hydrazine oxidation reaction(HzOR)assisted water electrolysis is efficiency for energy-saving and chlorine-free hydrogen production.Herein,the MoNi alloys supported on MoO_(2) nanorods with enlarged hollow diameter on Ni foam(MoNi@NF)are synthesized,which is constructed by limiting the outward diffusion of Ni via annealing and thermal reduction of NiMoO_(4) nanorods.When coupling HzOR and hydrogen evolution reaction(HER)by employing MoNi@NF as both anode and cathode in two-electrode seawater system,a low cell voltage of 0.54 V is required to achieve 1,000 mA·cm^(−2) and with long-term durability for 100 h to keep above 100 mA·cm^(−2) and nearly 100%Faradaic efficiency.It can save 2.94 W·h to generate per liter H_(2) relative to alkaline seawater electrolysis with 37%lower energy equivalent input.展开更多
With the recent development of the metasurface,generating an optical vortex in optical far or near fields is realized in various ways.However,to generate vortices in both the near and far fields simultaneously is stil...With the recent development of the metasurface,generating an optical vortex in optical far or near fields is realized in various ways.However,to generate vortices in both the near and far fields simultaneously is still a challenge,although it has great potential in the future compact and versatile photonic system.Here,a bi-channel optical vortex generator in both the near and far fields is proposed and demonstrated within a single metasurface,where the surface plasmon vortex and the far-field optical vortex can be simultancously generated under circularly polarized light.The ability of generating vortices with arbitrary topological charges is experimentally demon-strated,which agrces well with simulations.This approach provides great freedom to integrate different vortex generators in a single device and ofers new opprtunities for integrated optical communications,trapping,and other related fields.展开更多
基金This study was supported by the National Key R&D Program of China[grant numbers 2017YFC1502402,2017YFD0300201,and 2017YFA0605004]the funds of comprehensive monitoring of the Three Gorges Project,which was financed by the Ministry of Water Resources of China.
基金supported by the National Key R&D Program of China[grant numbers 2017YFD0300201,2017YFA0605004,and 2017YFC1502402]funds of comprehensive monitoring of the Three Gorges Project,which was financed by the Ministry of Water Resources of China。
基金jointly supported by the funds of the Strategic Cooperation Agreement Project between the China Meteorological Administration and the Three Gorges Corporation[Grant No.0704182]the Comprehensive Monitoring Program for Operational Safety of the Three Gorges Project[Grant No.SK2021015]financed by the Ministry of Water Resources of China.
基金This work was supported by CETC Joint Research Program under Grant 6141B08020101,6141B08080101National Key R&D Program of China under Grant 2018ZX09201014the National Natural Science Foundation of China under Grant 61002011.
文摘As a major function of smart transportation in smart cities,vehicle model recognition plays an important role in intelligent transportation.Due to the difference among different vehicle models recognition datasets,the accuracy of network model training in one scene will be greatly reduced in another one.However,if you don’t have a lot of vehicle model datasets for the current scene,you cannot properly train a model.To address this problem,we study the problem of cold start of vehicle model recognition under cross-scenario.Under the condition of small amount of datasets,combined with the method of transfer learning,load the DAN(Deep Adaptation Networks)and JAN(Joint Adaptation Networks)domain adaptation modules into the convolutional neural network AlexNet and ResNet,and get four models:AlexNet-JAN,AlexNet-DAN,ResNet-JAN,and ResNet-DAN which can achieve a higher accuracy at the beginning.Through experiments,transfer the vehicle model recognition from the network image dataset(source domain)to the surveillance-nature dataset(target domain),both Top-1 and Top-5 accuracy have been improved by at least 20%.
基金Supported by Project of Natural Science Foundation of Hebei Province(C2015204187)
文摘[Objectives] To determine the nine phenolic components in the leaves of Crataegus pinnatifida Bge. [Methods] The reversedphase high-performance liquid chromatography( RP-HPLC) was applied. [Results] Nine phenolic components showed a good linear relationship in the range of 2-500 μg/m L with r in the range of 0. 999 5-0. 999 9. The recovery rate of spiked samples ranged from 93. 7% to110. 2%,and the relative standard deviation was in the range of 0. 69%-4. 58%. The leaves of 29 cultivars of C. pinnatifida Bge. were measured,and the average content of the nine phenolic components was as follows: isoquercitrin,hyperoside,procyanidin C1,procyanidin D1,epicatechin,procyanidin B2,chlorogenic acid,eucomic acid,and vitexin 2 "-O-rhamnoside. The contents of flavonoids and phenolic acids were high,up to 15 mg/g D. W,and the content of procyanidins was up to 6 mg/g D. W. [Conclusions]This method is easy and accurate in determination of phenolic components in the leaves of C. pinnatifida Bge.
基金The work was supported by the Natural Science Basic Research Program of Shaanxi Province of China(2023-JC-YB-473)the Opening Fund of State Key Laboratory of Green Building in Western China(LSKF202314).The authors would like to express their gratitude to MogoEdit(http://en.mogoedit.com/)for the professional linguistic services provided.
文摘Window opening behavior significantly impacts indoor air quality,thermal comfort,and energy consumption.A field measurement was carried out in three typical rooms(a standard office,a meeting room and a smoking office)within an office building.The window state and the physical environment were continuously recorded during the measured periods.Three typical window opening behaviors were found in the measured samples,namely,active,moderate,and passive.The common logistic regression coefficient indicated that solar radiation exhibited the greatest effect on window opening behavior in the smoking office and standard office.Typically,window opening behavior in the meeting room was the most strongly correlated with time of the day,mainly because of the meeting schedule for occupants in the meeting room.This study discussed the dividing principles involved in setting the dummy variable interval level(discretizing continuous variables and dividing them into different intervals),and proposed a method to determine the optimal interval level of each variable.The improved model led to the increase in the prediction accuracy rate of the window being opened by 2.0%and 3.3%according to the comparison with the original model based on dummy variables and the common model based on continuous variables,respectively.This study can provide a reference value for simulating energy consumption in office buildings in the future.
文摘With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization techniques aim at achieving the structurally most efficient solution without any potential for architects or designers to control the design details.This paper introduces three strategies based on Bi-directional Evolutionary Structural Optimization(BESO)method to artificially pre-design the topological optimized structures.These strategies have been successfully applied in the computational morphogenesis of various structures for solving practical design problems.The results demonstrate that the developed methodology can provide the designer with structurally efficient and topologically different solutions according to their proposed designs with multi-filter radii,multi-volume fractions,and multi-weighting coefficients.This work establishes a general approach to integrating objective topology optimization methods with subjective human design preferences,which has great potential for practical applications in architecture and engineering industry.
基金supported by the National Natural Science Foundation of China(Nos.51772162 and 52072197)the Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)+3 种基金the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)the Major Scientific and Technological Innovation Project(No.2019JZZY020405)the Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09)the Taishan Scholar Young Talent Program(No.tsqn201909114).
文摘Seawater electrolysis could address the water scarcity issue and realize the grid-scale production of carbon-neutral hydrogen,while facing the challenge of high energy consumption and chloride corrosion.Thermodynamically more favorable hydrazine oxidation reaction(HzOR)assisted water electrolysis is efficiency for energy-saving and chlorine-free hydrogen production.Herein,the MoNi alloys supported on MoO_(2) nanorods with enlarged hollow diameter on Ni foam(MoNi@NF)are synthesized,which is constructed by limiting the outward diffusion of Ni via annealing and thermal reduction of NiMoO_(4) nanorods.When coupling HzOR and hydrogen evolution reaction(HER)by employing MoNi@NF as both anode and cathode in two-electrode seawater system,a low cell voltage of 0.54 V is required to achieve 1,000 mA·cm^(−2) and with long-term durability for 100 h to keep above 100 mA·cm^(−2) and nearly 100%Faradaic efficiency.It can save 2.94 W·h to generate per liter H_(2) relative to alkaline seawater electrolysis with 37%lower energy equivalent input.
基金National Key Reearch and Development Program of China(2017YFA0205700,2017YFA0206000,2019YFA0210203)National Natural Science Foundation of China(11374023,11674012,21790364,61422501,61521004)+2 种基金Beiing Natural Science Foundation(L140007,Z180011)Foundarion for the Author of National Excellent Doctoral Disertation of China(201420)National Program for Support of Top-notch Young Professionals(W02070003).
文摘With the recent development of the metasurface,generating an optical vortex in optical far or near fields is realized in various ways.However,to generate vortices in both the near and far fields simultaneously is still a challenge,although it has great potential in the future compact and versatile photonic system.Here,a bi-channel optical vortex generator in both the near and far fields is proposed and demonstrated within a single metasurface,where the surface plasmon vortex and the far-field optical vortex can be simultancously generated under circularly polarized light.The ability of generating vortices with arbitrary topological charges is experimentally demon-strated,which agrces well with simulations.This approach provides great freedom to integrate different vortex generators in a single device and ofers new opprtunities for integrated optical communications,trapping,and other related fields.
