The generation and reconnection of magneticflux ropes in a plasma irradiated by two Laguerre–Gaussian laser pulses with different frequen-cies and opposite topological charges are investigated numerically by particle-...The generation and reconnection of magneticflux ropes in a plasma irradiated by two Laguerre–Gaussian laser pulses with different frequen-cies and opposite topological charges are investigated numerically by particle-in-cell simulations.It is shown that twisted plasma currents and hence magneticflux ropes can be effectively generated as long as the laser frequency difference matches the electron plasma frequency.More importantly,subsequent reconnection of magneticflux ropes can occur.Typical signatures of magnetic reconnection,such as magnetic island formation and plasma heating,are identified in the reconnection of magneticflux ropes.Notably,it is found that a strong axial magneticfield can be generated on the axis,owing to the azimuthal current induced during the reconnection of the ropes.This indicates that in the reconnection of magneticflux ropes,the energy can be transferred not only from the magneticfield to the plasma but also from the plasma current back to the magneticfield.This work opens a new avenue to the study of magneticflux ropes,which helps in understanding magnetic topology changes,and resultant magnetic energy dissipation,plasma heating,and particle acceleration found in solarflares,and magnetic confinement fusion devices.展开更多
This study analyzes the User Interface(UI)and User Experience(UX)of information systems that provide local government information.The systems analyzed are the Local Administrative Comprehensive Information Disclosure ...This study analyzes the User Interface(UI)and User Experience(UX)of information systems that provide local government information.The systems analyzed are the Local Administrative Comprehensive Information Disclosure System(Zheripan),the Integrated Local Financial Disclosure System(Qinching Online),and the Local Regulations Information System(12348 Zhejiang Legal Network).The Local Administrative Comprehensive Information Disclosure System offers public service and personnel information,while the Integrated Local Financial Disclosure System provides financial information,and the Local Regulations Information System offers legal information as its main content.The analysis framework utilized three elements:objective data,psychological factors,and heuristic evaluation.The results of the first objective data analysis show that approximately 70%of visits to Zheripan and Qinching Online are through search,and the time spent on the homepage is short.In contrast,about 70%of visits to the 12348 Zhejiang Legal Network are direct visits,with users browsing multiple pages with a clear purpose.In terms of data provision methods,Zheripan provides two types of data in three formats,Qinching Online offers 28 types of data in five formats,and 12348 Zhejiang Legal Network provides one type of information in a single format.The second psychological factor analysis found that all three websites had a number of menus suitable for short-term cognitive capacity.However,only one of the sites had a layout that considered the user’s eye movement.Finally,the heuristic evaluation revealed that most of the evaluation criteria were not met.While the design is relatively simple and follows standards,feedback for users,error prevention,and help options were lacking.Moreover,the user-specific usability was low,and the systems remained at the information-providing level.Based on these findings,both short-term and long-term improvement measures for creating an interactive system beyond simple information disclosure are proposed.展开更多
Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar r...Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar regions.We used a global climate model(GCM)to investigate the impact on atmospheric chemistry from a change to the contemporary DMS fl ux to that which has been projected for the late 21 st century.The perturbed simulation corresponded to conditions that pertained to a tripling of equivalent CO 2,which was estimated to occur by year 2090 based on current worst-case greenhouse gas emission scenarios.The changes in zonal mean DMS fl ux were applied to 50°S–70°S Antarctic(ANT)and 65°N–80°N Arctic(ARC)regions.The results indicate that there are clearly diff erent impacts after perturbation in the southern and northern polar regions.Most quantities related to the sulfur cycle show a higher increase in ANT.However,most sulfur compounds have higher peaks in ARC.The perturbation in DMS fl ux leads to an increase of atmospheric DMS of about 45%in ANT and 33.6%in ARC.The sulfur dioxide(SO 2)vertical integral increases around 43%in ANT and 7.5%in ARC.Sulfate(SO 4)vertical integral increases by 17%in ANT and increases around 6%in ARC.Sulfur emissions increases by 21%in ANT and increases by 9.7%in ARC.However,oxidation of DMS by OH increases by 38.2%in ARC and by 15.17%in ANT.Aerosol optical depth(AOD)increases by 4%in the ARC and by 17.5%in the ANT,and increases by 22.8%in austral summer.The importance of the perturbation of the biogenic source to future aerosol burden in polar regions leads to a cooling in surface temperature of 1 K in the ANT and 0.8 K in the ARC.Generally,polar regions in the Antarctic Ocean will have a higher off setting eff ect on warming after DMS fl ux perturbation.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12375236 and 12135009)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA25050100 and XDA25010100).
文摘The generation and reconnection of magneticflux ropes in a plasma irradiated by two Laguerre–Gaussian laser pulses with different frequen-cies and opposite topological charges are investigated numerically by particle-in-cell simulations.It is shown that twisted plasma currents and hence magneticflux ropes can be effectively generated as long as the laser frequency difference matches the electron plasma frequency.More importantly,subsequent reconnection of magneticflux ropes can occur.Typical signatures of magnetic reconnection,such as magnetic island formation and plasma heating,are identified in the reconnection of magneticflux ropes.Notably,it is found that a strong axial magneticfield can be generated on the axis,owing to the azimuthal current induced during the reconnection of the ropes.This indicates that in the reconnection of magneticflux ropes,the energy can be transferred not only from the magneticfield to the plasma but also from the plasma current back to the magneticfield.This work opens a new avenue to the study of magneticflux ropes,which helps in understanding magnetic topology changes,and resultant magnetic energy dissipation,plasma heating,and particle acceleration found in solarflares,and magnetic confinement fusion devices.
文摘This study analyzes the User Interface(UI)and User Experience(UX)of information systems that provide local government information.The systems analyzed are the Local Administrative Comprehensive Information Disclosure System(Zheripan),the Integrated Local Financial Disclosure System(Qinching Online),and the Local Regulations Information System(12348 Zhejiang Legal Network).The Local Administrative Comprehensive Information Disclosure System offers public service and personnel information,while the Integrated Local Financial Disclosure System provides financial information,and the Local Regulations Information System offers legal information as its main content.The analysis framework utilized three elements:objective data,psychological factors,and heuristic evaluation.The results of the first objective data analysis show that approximately 70%of visits to Zheripan and Qinching Online are through search,and the time spent on the homepage is short.In contrast,about 70%of visits to the 12348 Zhejiang Legal Network are direct visits,with users browsing multiple pages with a clear purpose.In terms of data provision methods,Zheripan provides two types of data in three formats,Qinching Online offers 28 types of data in five formats,and 12348 Zhejiang Legal Network provides one type of information in a single format.The second psychological factor analysis found that all three websites had a number of menus suitable for short-term cognitive capacity.However,only one of the sites had a layout that considered the user’s eye movement.Finally,the heuristic evaluation revealed that most of the evaluation criteria were not met.While the design is relatively simple and follows standards,feedback for users,error prevention,and help options were lacking.Moreover,the user-specific usability was low,and the systems remained at the information-providing level.Based on these findings,both short-term and long-term improvement measures for creating an interactive system beyond simple information disclosure are proposed.
文摘Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar regions.We used a global climate model(GCM)to investigate the impact on atmospheric chemistry from a change to the contemporary DMS fl ux to that which has been projected for the late 21 st century.The perturbed simulation corresponded to conditions that pertained to a tripling of equivalent CO 2,which was estimated to occur by year 2090 based on current worst-case greenhouse gas emission scenarios.The changes in zonal mean DMS fl ux were applied to 50°S–70°S Antarctic(ANT)and 65°N–80°N Arctic(ARC)regions.The results indicate that there are clearly diff erent impacts after perturbation in the southern and northern polar regions.Most quantities related to the sulfur cycle show a higher increase in ANT.However,most sulfur compounds have higher peaks in ARC.The perturbation in DMS fl ux leads to an increase of atmospheric DMS of about 45%in ANT and 33.6%in ARC.The sulfur dioxide(SO 2)vertical integral increases around 43%in ANT and 7.5%in ARC.Sulfate(SO 4)vertical integral increases by 17%in ANT and increases around 6%in ARC.Sulfur emissions increases by 21%in ANT and increases by 9.7%in ARC.However,oxidation of DMS by OH increases by 38.2%in ARC and by 15.17%in ANT.Aerosol optical depth(AOD)increases by 4%in the ARC and by 17.5%in the ANT,and increases by 22.8%in austral summer.The importance of the perturbation of the biogenic source to future aerosol burden in polar regions leads to a cooling in surface temperature of 1 K in the ANT and 0.8 K in the ARC.Generally,polar regions in the Antarctic Ocean will have a higher off setting eff ect on warming after DMS fl ux perturbation.
