All staff members at our Academy praise the key decision made by the Party’s leading group at the CAS to implement the Program of Knowledge Innovation. Also, they believe the move offers both our Academy and its rese...All staff members at our Academy praise the key decision made by the Party’s leading group at the CAS to implement the Program of Knowledge Innovation. Also, they believe the move offers both our Academy and its research institutes a precious opportunity for rejuvenating China’ s S&T endeavors at the turn of the century. Our Institute has a展开更多
"The year of 2022 marked the70th anniversary of the founding of the China Council for the Promotion of International Trade(CCPIT),and it was also a milestone in the development history of trade promotion.Under th..."The year of 2022 marked the70th anniversary of the founding of the China Council for the Promotion of International Trade(CCPIT),and it was also a milestone in the development history of trade promotion.Under the strong leadership of the Central Committee of the Communist Party of China(CPC)with Comrade Xi Jinping at its core,the national trade promotion system faced up to difficulties,forged ahead.展开更多
During the Spring Festival in 2022,China Cultural Center in Mexico focused on the themes of Winter Olympics with Ice and Snow,the 50th anniversary of the establishment of diplomatic relations between China and Mexico,...During the Spring Festival in 2022,China Cultural Center in Mexico focused on the themes of Winter Olympics with Ice and Snow,the 50th anniversary of the establishment of diplomatic relations between China and Mexico,friendship between the two countries,etc.,and cooperated with 20-plus Chinese and Mexican institutions to hold 11 categories of 180-plus Spring Festival celebration activities,such as Year of the Tiger Costume Contest,Happy Spring Festival Quiz Show,the 8th Children's Painting Competition:China in My Imagination in the theme of Winter Olympics and ice&snow sports.展开更多
The index systems are not only the tools to evaluate existing practice results, but also the guides to the future development direction and development way of practical activities. ＂Well-off society＂ is a relatively...The index systems are not only the tools to evaluate existing practice results, but also the guides to the future development direction and development way of practical activities. ＂Well-off society＂ is a relatively vague concept, and the contents of it ceaselessly change with the advancement of society and the development of productivity. Now the construction of a well-off society in an all-round way enters a critical stage, so the original evaluation standards must change with gradual advancement of the construction goal of a well-off society. So it is very necessary for us to build a comprehensive evaluation index system and make it better and better to provide effective statistical consultation and statistical supervision for constructing a well-off society in an all-round way. This paper attempts to analyze the current evaluation index system, then puts forward the general thinking and flame work of the index system of building a well-off society in an all-round way.展开更多
Spanish Website Rebellion published an article titled The West Perfecting Its Techniques to Hurt China by U.S. writer, filmmaker and journalist Andre Vltchek on November 12, 2010. Excerpts from the article follow:
In vivo fluorescence imaging in the second near-infrared window(NIR-II)has been considered as a promising technique for visualizing mammals.However,the definition of the NIR-II region and the mechanism accounting for ...In vivo fluorescence imaging in the second near-infrared window(NIR-II)has been considered as a promising technique for visualizing mammals.However,the definition of the NIR-II region and the mechanism accounting for the excellent performance still need to be perfected.Herein,we simulate the photon propagation in the NIR region(to 2340 nm),confirm the positive contribution of moderate light absorption by water in intravital imaging and perfect the NIR-II window as 900–1880 nm,where 1400–1500 and 1700–1880 nm are defined as NIR-IIx and NIR-IIc regions,respectively.Moreover,2080–2340 nm is newly proposed as the third near-infrared(NIR-III)window,which is believed to provide the best imaging quality.The wide-field fluorescence microscopy in the brain is performed around the NIRIIx region,with excellent optical sectioning strength and the largest imaging depth of intravital NIR-II fluorescence microscopy to date.We also propose 1400 nm long-pass detection in off-peak NIR-II imaging whose performance exceeds that of NIR-IIb imaging,using bright fluorophores with short emission wavelength.展开更多
Raphael Holzer is a man who knows how to drink.Having masterminded the acclaimed drinks programs at cult Hong Kong eateries Yardbird and Ronin,hes moved on to distilling his own Fernet spirit according to an age-old f...Raphael Holzer is a man who knows how to drink.Having masterminded the acclaimed drinks programs at cult Hong Kong eateries Yardbird and Ronin,hes moved on to distilling his own Fernet spirit according to an age-old family recipe,in addition to spearheading the bar at Highline.We caught叩with the man himself to talk perfect highballs,reviving classic 60s drinks and the importance of amazing ice.展开更多
Cognitive bias,stemming from electronic measurement error and variability in human perception,exists in cognitive electronic warfare and affects the outcomes of conflicts.In this paper,the dynamic game approach is emp...Cognitive bias,stemming from electronic measurement error and variability in human perception,exists in cognitive electronic warfare and affects the outcomes of conflicts.In this paper,the dynamic game approach is employed to develop a model for cognitive bias induced by incomplete information and measurement errors in cognitive radar countermeasures.The payoffs for both parties are calculated using the radar's anti-jamming strategy matrix A and the jammer's jamming strategy matrix B.With perfect Bayesian equilibrium,a dynamic radar countermeasure model is established,and the impact of cognitive bias is analyzed.Drawing inspiration from the cognitive bias analysis method used in stock market trading,a cognitive bias model for cognitive radar countermeasures is introduced,and its correctness is mathematically proved.A gaming scenario involving the AN/SPY-1 radar and a smart jammer is set up to analyze the influence of cognitive bias on game outcomes.Simulation results validate the effectiveness of the proposed method.展开更多
Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodi...Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodicity.Here,we provide both numerical and analytical evidence that a depth gradient metasurface can achieve discrete ultra-broadband perfect anomalous reflection in the microwave range in the absence of geometric periodicity.Remarkably,by adjusting the operating frequency of the incident wave,the same effect can be steadily obtained via a physically equivalent phase periodicity in the PGM.Based on this mechanism,a perfect retroreflector with a broadband response ranging from 1 GHz to 40 GHz is realized.Our work has promising applications in communication,source tracking,and military satellites.展开更多
4 When you buy something,do you buy new or usecP Both can be good.When you buy things new,they're in perfect condition.These things usually last longer because they're new.New things also often have the newest...4 When you buy something,do you buy new or usecP Both can be good.When you buy things new,they're in perfect condition.These things usually last longer because they're new.New things also often have the newest features and design.展开更多
This paper presents a tunable and polarization-insensitive wideband metamaterial absorber based on single-layer graphene.By comparing the simulated experimental data with theoretical derivations,it was found that the ...This paper presents a tunable and polarization-insensitive wideband metamaterial absorber based on single-layer graphene.By comparing the simulated experimental data with theoretical derivations,it was found that the absorbance of the material can be sustained above 90%in the frequency range of 2.78 to 7.14(4.36)THz,of which the absorption rate exceeds 99%in the frequency range of 4.1–4.54(0.44)THz,and remarkably,perfect absorption is achieved at4.32 THz.In the range of 2.78–7.14 THz,the average absorption rate is 96.1%,by adjusting the physical size of the graphene layer pattern,we can modify the working band gap of the absorber.By applying a voltage to modulate the Fermi level of graphene,we can increase the absorption bandwidth.When the chemical potential is 1.0 e V,at the bandwidth of 4.36 THz,its absorption rate exceeds 90%.The working principle of absorbing materials was deeply explored using the principles of electromagnetic field distribution and impedance adaptation.Through detailed analysis of different polarization states and incident angles,we found that the absorber is not sensitive to polarization due to its symmetrical structure,and found that it exhibits low sensitivity at incidence angles.In addition,after comparative analysis,significant differences were observed in the absorption efficiency of the absorber under various relaxation time conditions,and the obtained data were elaborated in detail using the carrier mechanism of plasma vibration.We found that in addition to obtaining an almost perfect absorber with wide band by adjusting the parameters,it is also feasible to obtain an approximately narrow band absorber by changing the relaxation time without having to remanufacture the structure.The absorber offers several advantages,including tunability,a wide absorption band,a high absorption rate,polarization insensitivity,and a simple structure.Therefore,this absorber exhibits great potential for absorption,monitoring,and sensing in the terahertz band.展开更多
In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted co...In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted combination,the non-uniform rational B-spline(NURBS)functions are employed as basis functions.Moreover,the unbounded and artificial domains,defined in the PML method,are contained in a single patch domain.Based on the proposed scheme,the approximation of the geometry problem is set in a new scheme in which the PML’s absorbing and attenuation properties and the description of traveling waves can be represented.This includes a higher continuity and smoother approximation of the computed domain.As high-order NURBS basis functions are non-interpolatory,a penalty method is present to apply a time-dependent displacement load.The performance of the NURBS-based PML is analyzed through numerical examples for 1D and 2D domains,considering homogeneous and heterogeneous media.Further,we verify the long-time numerical stability of the present method.The developed method can be used to simulate hypothetical stratified domains commonly encountered in soil-structure interaction analyses.展开更多
Broadband and perfect terahertz absorber based on multilayer metamaterial using cross-ring patterned structures is proposed and investigated.The structure of the absorber is double absorption layers consisting of a ch...Broadband and perfect terahertz absorber based on multilayer metamaterial using cross-ring patterned structures is proposed and investigated.The structure of the absorber is double absorption layers consisting of a chromium cross ring and eight isosceles right triangles.The unique structure of the double absorbing layers excites the electric dipole multimode resonance,giving rise to high absorption performance.Meanwhile,the influence of construal parameters on absorber behavior is also discussed.The numerical results show that the absorption achieves over 90%ranging from 2.45 THz to 6.25 THz and 99%absorption in the range of 3.7—5.3 THz.The realization of broadband and perfect absorber is described using the impedance matching principle.It is obviously found that the absorber is insensitive to the high angle of incidence for both transverse electric(TE)and transverse magnetic(TM)polarizations.Compared with the former reports,this absorber has remarkable improved absorption efficiency and smaller period.The terahertz absorber may be found applications in the fields of energy capture and thermal detection.展开更多
Acoustic wave isolation and noise reduction are significant challenges in the fields of physics and various applications.Traditional noise-control devices are often hampered by substantial size limitations,and their o...Acoustic wave isolation and noise reduction are significant challenges in the fields of physics and various applications.Traditional noise-control devices are often hampered by substantial size limitations,and their operational efficacy is generally restricted to planar waveforms.In this study,we demonstrate perfect confinement of acoustic vortex waves using an acoustic metacage consisting of phase-gradient metasurfaces.By leveraging the parity-reversed diffraction rule of phase-gradient metasurfaces,the designed metacage exhibited remarkable capabilities for the perfect confinement of acoustic vortex waves,showing robust performance even in the presence of source offsets.These findings present a promising strategy for developing precise and adaptable acoustic confinement technologies.展开更多
Each year,Lin Haiyan,president of the Chinatown Foundation in Mauritius,dedicates significant time and effort to organising the Spring Festival celebrations.During the Spring Festival season in February 2024,the Mauri...Each year,Lin Haiyan,president of the Chinatown Foundation in Mauritius,dedicates significant time and effort to organising the Spring Festival celebrations.During the Spring Festival season in February 2024,the Mauritius National Multi-Sport Complex was adorned with large red lanterns and Chinese knots,creating a vibrant setting for the festivities.The event featured captivating performances,including lion and dragon dances,parades showcasing traditional Chinese women’s clothing,or qipao,singing,and tai chi demonstrations,providing the perfect atmosphere to celebrate the Chinese New Year.展开更多
The stabilities and migration behaviors of 1/2<110>perfect vacancy loops in various FCC metals are studied by molecular dynamics(MD)simulations.Compression strain can suppress the spontaneous structural transfor...The stabilities and migration behaviors of 1/2<110>perfect vacancy loops in various FCC metals are studied by molecular dynamics(MD)simulations.Compression strain can suppress the spontaneous structural transformation from perfect vacancy loops to sessile stacking fault tetrahedra(SFTs).Instead,an intermediate stable structure containing four stacking faults and exhibiting one-dimensional(1-D)fast migration is formed.The migration is essentially enhanced with the compression strain,the corresponding migration barrier can be as low as 0.002 eV for perfect loop containing 100 vacancies in Cu under 4%compression strain.Furthermore,the stabilities and mobilities of intermediate structures are increased with the decrease of stacking fault energy(SFE)for Au,Cu,Ni and Al.Two different migration modes,including collective glide and change of habit planes,are observed,the dominant migration behavior depends on the loop size and compression strain.The energetics of 1/2<110>perfect vacancy loops and SFTs,as well as the energy landscapes of two 1-D migration modes,are calculated to interpret its structural transformation and migration behaviors.This study first reveals the fast migration behaviors of perfect vacancy loops in FCC metals and the underlying mechanisms,especially the important role of compression strain,which would provide important clues for understanding the variations of microstructures and properties related with vacancy behaviors.展开更多
1 Tuan Pham was feeling pretty good about himself as he approached the 12-mile mark of the Long Beach Half Marathon in Southern California.The run was the 47-year-old's seventh such event,and he couldn't wait ...1 Tuan Pham was feeling pretty good about himself as he approached the 12-mile mark of the Long Beach Half Marathon in Southern California.The run was the 47-year-old's seventh such event,and he couldn't wait to celebrate at the finish line with his teenage son,who had raced ahead.Pham took another step or two,and that was the last thing he could remember.展开更多
文摘All staff members at our Academy praise the key decision made by the Party’s leading group at the CAS to implement the Program of Knowledge Innovation. Also, they believe the move offers both our Academy and its research institutes a precious opportunity for rejuvenating China’ s S&T endeavors at the turn of the century. Our Institute has a
文摘"The year of 2022 marked the70th anniversary of the founding of the China Council for the Promotion of International Trade(CCPIT),and it was also a milestone in the development history of trade promotion.Under the strong leadership of the Central Committee of the Communist Party of China(CPC)with Comrade Xi Jinping at its core,the national trade promotion system faced up to difficulties,forged ahead.
文摘During the Spring Festival in 2022,China Cultural Center in Mexico focused on the themes of Winter Olympics with Ice and Snow,the 50th anniversary of the establishment of diplomatic relations between China and Mexico,friendship between the two countries,etc.,and cooperated with 20-plus Chinese and Mexican institutions to hold 11 categories of 180-plus Spring Festival celebration activities,such as Year of the Tiger Costume Contest,Happy Spring Festival Quiz Show,the 8th Children's Painting Competition:China in My Imagination in the theme of Winter Olympics and ice&snow sports.
文摘The index systems are not only the tools to evaluate existing practice results, but also the guides to the future development direction and development way of practical activities. ＂Well-off society＂ is a relatively vague concept, and the contents of it ceaselessly change with the advancement of society and the development of productivity. Now the construction of a well-off society in an all-round way enters a critical stage, so the original evaluation standards must change with gradual advancement of the construction goal of a well-off society. So it is very necessary for us to build a comprehensive evaluation index system and make it better and better to provide effective statistical consultation and statistical supervision for constructing a well-off society in an all-round way. This paper attempts to analyze the current evaluation index system, then puts forward the general thinking and flame work of the index system of building a well-off society in an all-round way.
文摘Spanish Website Rebellion published an article titled The West Perfecting Its Techniques to Hurt China by U.S. writer, filmmaker and journalist Andre Vltchek on November 12, 2010. Excerpts from the article follow:
基金This work was supported by the National Natural Science Foundation of China(61975172,82001874,and 21974104)Fundamental Research Funds for the Central Universities(2020-KYY-511108-0007)Natural Science Foundation of Zhejiang Province(LR17F050001).
文摘In vivo fluorescence imaging in the second near-infrared window(NIR-II)has been considered as a promising technique for visualizing mammals.However,the definition of the NIR-II region and the mechanism accounting for the excellent performance still need to be perfected.Herein,we simulate the photon propagation in the NIR region(to 2340 nm),confirm the positive contribution of moderate light absorption by water in intravital imaging and perfect the NIR-II window as 900–1880 nm,where 1400–1500 and 1700–1880 nm are defined as NIR-IIx and NIR-IIc regions,respectively.Moreover,2080–2340 nm is newly proposed as the third near-infrared(NIR-III)window,which is believed to provide the best imaging quality.The wide-field fluorescence microscopy in the brain is performed around the NIRIIx region,with excellent optical sectioning strength and the largest imaging depth of intravital NIR-II fluorescence microscopy to date.We also propose 1400 nm long-pass detection in off-peak NIR-II imaging whose performance exceeds that of NIR-IIb imaging,using bright fluorophores with short emission wavelength.
文摘Raphael Holzer is a man who knows how to drink.Having masterminded the acclaimed drinks programs at cult Hong Kong eateries Yardbird and Ronin,hes moved on to distilling his own Fernet spirit according to an age-old family recipe,in addition to spearheading the bar at Highline.We caught叩with the man himself to talk perfect highballs,reviving classic 60s drinks and the importance of amazing ice.
文摘Cognitive bias,stemming from electronic measurement error and variability in human perception,exists in cognitive electronic warfare and affects the outcomes of conflicts.In this paper,the dynamic game approach is employed to develop a model for cognitive bias induced by incomplete information and measurement errors in cognitive radar countermeasures.The payoffs for both parties are calculated using the radar's anti-jamming strategy matrix A and the jammer's jamming strategy matrix B.With perfect Bayesian equilibrium,a dynamic radar countermeasure model is established,and the impact of cognitive bias is analyzed.Drawing inspiration from the cognitive bias analysis method used in stock market trading,a cognitive bias model for cognitive radar countermeasures is introduced,and its correctness is mathematically proved.A gaming scenario involving the AN/SPY-1 radar and a smart jammer is set up to analyze the influence of cognitive bias on game outcomes.Simulation results validate the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274313,62275184,and 62411540033)Collaborative Innovation Center of Suzhou Nano Science and Technology,Suzhou Basic Research Project(Grant No.SJC2023003)+1 种基金the Gusu Leading Talent Plan for Scientific and Technological Innovation and Entrepreneurship(Grant No.ZXL2024400)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodicity.Here,we provide both numerical and analytical evidence that a depth gradient metasurface can achieve discrete ultra-broadband perfect anomalous reflection in the microwave range in the absence of geometric periodicity.Remarkably,by adjusting the operating frequency of the incident wave,the same effect can be steadily obtained via a physically equivalent phase periodicity in the PGM.Based on this mechanism,a perfect retroreflector with a broadband response ranging from 1 GHz to 40 GHz is realized.Our work has promising applications in communication,source tracking,and military satellites.
文摘4 When you buy something,do you buy new or usecP Both can be good.When you buy things new,they're in perfect condition.These things usually last longer because they're new.New things also often have the newest features and design.
基金the support form the National Natural Science Foundation of China(Grant Nos.51606158,11604311,12074151)the Funded by the Guangxi Science and Technology Base and Talent Special Project(Grant No.AD21075009)+3 种基金the funded by the Sichuan Science and Technology Program(Grant No.2021JDRC0022)the Open Fund of the Key Laboratory for Metallurgical Equipment and Control Technology of Ministry of Education in Wuhan University of Science and Technology,China(Grant Nos.MECOF2022B01MECOF2023B04)the Project supported by Guangxi Key Laboratory of Precision Navigation Technology and Application,Guilin University of Electronic Technology(Grant No.DH202321)。
文摘This paper presents a tunable and polarization-insensitive wideband metamaterial absorber based on single-layer graphene.By comparing the simulated experimental data with theoretical derivations,it was found that the absorbance of the material can be sustained above 90%in the frequency range of 2.78 to 7.14(4.36)THz,of which the absorption rate exceeds 99%in the frequency range of 4.1–4.54(0.44)THz,and remarkably,perfect absorption is achieved at4.32 THz.In the range of 2.78–7.14 THz,the average absorption rate is 96.1%,by adjusting the physical size of the graphene layer pattern,we can modify the working band gap of the absorber.By applying a voltage to modulate the Fermi level of graphene,we can increase the absorption bandwidth.When the chemical potential is 1.0 e V,at the bandwidth of 4.36 THz,its absorption rate exceeds 90%.The working principle of absorbing materials was deeply explored using the principles of electromagnetic field distribution and impedance adaptation.Through detailed analysis of different polarization states and incident angles,we found that the absorber is not sensitive to polarization due to its symmetrical structure,and found that it exhibits low sensitivity at incidence angles.In addition,after comparative analysis,significant differences were observed in the absorption efficiency of the absorber under various relaxation time conditions,and the obtained data were elaborated in detail using the carrier mechanism of plasma vibration.We found that in addition to obtaining an almost perfect absorber with wide band by adjusting the parameters,it is also feasible to obtain an approximately narrow band absorber by changing the relaxation time without having to remanufacture the structure.The absorber offers several advantages,including tunability,a wide absorption band,a high absorption rate,polarization insensitivity,and a simple structure.Therefore,this absorber exhibits great potential for absorption,monitoring,and sensing in the terahertz band.
文摘In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted combination,the non-uniform rational B-spline(NURBS)functions are employed as basis functions.Moreover,the unbounded and artificial domains,defined in the PML method,are contained in a single patch domain.Based on the proposed scheme,the approximation of the geometry problem is set in a new scheme in which the PML’s absorbing and attenuation properties and the description of traveling waves can be represented.This includes a higher continuity and smoother approximation of the computed domain.As high-order NURBS basis functions are non-interpolatory,a penalty method is present to apply a time-dependent displacement load.The performance of the NURBS-based PML is analyzed through numerical examples for 1D and 2D domains,considering homogeneous and heterogeneous media.Further,we verify the long-time numerical stability of the present method.The developed method can be used to simulate hypothetical stratified domains commonly encountered in soil-structure interaction analyses.
基金supported by the National Natural Science Foundation of China(No.61505160)the Innovation Capability Support Program of Shaanxi(No.2018KJXX-042)+1 种基金the Natural Science Basic Research Program of Shaanxi(No.2019JM-084)the State Key Laboratory of Transient Optics and Photonics(No.SKLST202108)。
文摘Broadband and perfect terahertz absorber based on multilayer metamaterial using cross-ring patterned structures is proposed and investigated.The structure of the absorber is double absorption layers consisting of a chromium cross ring and eight isosceles right triangles.The unique structure of the double absorbing layers excites the electric dipole multimode resonance,giving rise to high absorption performance.Meanwhile,the influence of construal parameters on absorber behavior is also discussed.The numerical results show that the absorption achieves over 90%ranging from 2.45 THz to 6.25 THz and 99%absorption in the range of 3.7—5.3 THz.The realization of broadband and perfect absorber is described using the impedance matching principle.It is obviously found that the absorber is insensitive to the high angle of incidence for both transverse electric(TE)and transverse magnetic(TM)polarizations.Compared with the former reports,this absorber has remarkable improved absorption efficiency and smaller period.The terahertz absorber may be found applications in the fields of energy capture and thermal detection.
基金supported by the Undergraduate Training Program for Innovation and Entrepreneurship,Soochow University(Grant No.202410285001Z)the National Natural Science Foundation of China(Grant Nos.12274313 and 12374293)。
文摘Acoustic wave isolation and noise reduction are significant challenges in the fields of physics and various applications.Traditional noise-control devices are often hampered by substantial size limitations,and their operational efficacy is generally restricted to planar waveforms.In this study,we demonstrate perfect confinement of acoustic vortex waves using an acoustic metacage consisting of phase-gradient metasurfaces.By leveraging the parity-reversed diffraction rule of phase-gradient metasurfaces,the designed metacage exhibited remarkable capabilities for the perfect confinement of acoustic vortex waves,showing robust performance even in the presence of source offsets.These findings present a promising strategy for developing precise and adaptable acoustic confinement technologies.
文摘Each year,Lin Haiyan,president of the Chinatown Foundation in Mauritius,dedicates significant time and effort to organising the Spring Festival celebrations.During the Spring Festival season in February 2024,the Mauritius National Multi-Sport Complex was adorned with large red lanterns and Chinese knots,creating a vibrant setting for the festivities.The event featured captivating performances,including lion and dragon dances,parades showcasing traditional Chinese women’s clothing,or qipao,singing,and tai chi demonstrations,providing the perfect atmosphere to celebrate the Chinese New Year.
基金supported by the National Magnetic Confinement Fusion Energy Research Project(No.2024YFE03150000)the National Natural Science Foundation of China(Nos.11905057,11935004,and 12175059)the Natural Science Foundation of Hunan Province(No.2021JJ30002).
文摘The stabilities and migration behaviors of 1/2<110>perfect vacancy loops in various FCC metals are studied by molecular dynamics(MD)simulations.Compression strain can suppress the spontaneous structural transformation from perfect vacancy loops to sessile stacking fault tetrahedra(SFTs).Instead,an intermediate stable structure containing four stacking faults and exhibiting one-dimensional(1-D)fast migration is formed.The migration is essentially enhanced with the compression strain,the corresponding migration barrier can be as low as 0.002 eV for perfect loop containing 100 vacancies in Cu under 4%compression strain.Furthermore,the stabilities and mobilities of intermediate structures are increased with the decrease of stacking fault energy(SFE)for Au,Cu,Ni and Al.Two different migration modes,including collective glide and change of habit planes,are observed,the dominant migration behavior depends on the loop size and compression strain.The energetics of 1/2<110>perfect vacancy loops and SFTs,as well as the energy landscapes of two 1-D migration modes,are calculated to interpret its structural transformation and migration behaviors.This study first reveals the fast migration behaviors of perfect vacancy loops in FCC metals and the underlying mechanisms,especially the important role of compression strain,which would provide important clues for understanding the variations of microstructures and properties related with vacancy behaviors.
文摘1 Tuan Pham was feeling pretty good about himself as he approached the 12-mile mark of the Long Beach Half Marathon in Southern California.The run was the 47-year-old's seventh such event,and he couldn't wait to celebrate at the finish line with his teenage son,who had raced ahead.Pham took another step or two,and that was the last thing he could remember.
