Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical work.During the last 60 years,designing molecular structures capable of generat...Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical work.During the last 60 years,designing molecular structures capable of generating unidirectional mechanical motion at the nanoscale has been the topic of intense research.Effective progress has been made,attributed to advances in various fields such as supramolecular chemistry,biology and nanotechnology,and informatics.However,individual molecular machines are only capable of producing nanometer work and generally have only a single functionality.In order to address these problems,collective behaviors realized by integrating several or more of these individual mechanical units in space and time have become a new paradigm.In this review,we comprehensively discuss recent developments in the collective behaviors of molecular machines.In particular,collective behavior is divided into two paradigms.One is the appropriate integration of molecular machines to efficiently amplify molecular motions and deformations to construct novel functional materials.The other is the construction of swarming modes at the supramolecular level to perform nanoscale or microscale operations.We discuss design strategies for both modes and focus on the modulation of features and properties.Subsequently,in order to address existing challenges,the idea of transferring experience gained in the field of micro/nano robotics is presented,offering prospects for future developments in the collective behavior of molecular machines.展开更多
The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(LQMD.RMF). Using the LQMD.RMF, the properties of collective flow and pion production were investigated sys...The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(LQMD.RMF). Using the LQMD.RMF, the properties of collective flow and pion production were investigated systematically for nuclear reactions with various isospin asymmetries. The directed and elliptic flows of the LQMD.RMF are able to describe the experimental data of STAR Collaboration. The directed flow difference between free neutrons and protons was associated with the stiffness of the symmetry energy, that is, a softer symmetry energy led to a larger flow difference. For various collision energies, the ratio between the π^(-) and π^(+) yields increased with a decrease in the slope parameter of the symmetry energy. When the collision energy was 270 MeV/nucleon, the single ratio of the pion transverse momentum spectra also increased with decreasing slope parameter of the symmetry energy in both nearly symmetric and neutron-rich systems.However, it is difficult to constrain the stiffness of the symmetry energy with the double ratio because of the lack of threshold energy correction on the pion production.展开更多
In the current information society, the dissemination mechanisms and evolution laws of individual or collective opinions and their behaviors are the research hot topics in the field of opinion dynamics. First, in this...In the current information society, the dissemination mechanisms and evolution laws of individual or collective opinions and their behaviors are the research hot topics in the field of opinion dynamics. First, in this paper, a two-layer network consisting of an individual-opinion layer and a collective-opinion layer is constructed, and a dissemination model of opinions incorporating higher-order interactions(i.e. OIHOI dissemination model) is proposed. Furthermore, the dynamic equations of opinion dissemination for both individuals and groups are presented. Using Lyapunov's first method,two equilibrium points, including the negative consensus point and positive consensus point, and the dynamic equations obtained for opinion dissemination, are analyzed theoretically. In addition, for individual opinions and collective opinions,some conditions for reaching negative consensus and positive consensus as well as the theoretical expression for the dissemination threshold are put forward. Numerical simulations are carried to verify the feasibility and effectiveness of the proposed theoretical results, as well as the influence of the intra-structure, inter-connections, and higher-order interactions on the dissemination and evolution of individual opinions. The main results are as follows.(i) When the intra-structure of the collective-opinion layer meets certain characteristics, then a negative or positive consensus is easier to reach for individuals.(ii) Both negative consensus and positive consensus perform best in mixed type of inter-connections in the two-layer network.(iii) Higher-order interactions can quickly eliminate differences in individual opinions, thereby enabling individuals to reach consensus faster.展开更多
Coinciding with World Water Day celebrations and under the slogan"Water,a shared responsibility,"the eco-efficient textile technology company,Jeanologia,calls on this productive sector,appealing for a real c...Coinciding with World Water Day celebrations and under the slogan"Water,a shared responsibility,"the eco-efficient textile technology company,Jeanologia,calls on this productive sector,appealing for a real change,away from greenwashing and towards concrete and collective action.展开更多
The entry of collective construction land for business purposes is an important measure for deepening the reform of the rural land system,promoting the flow of urban and rural factors,and realizing rural revitalizatio...The entry of collective construction land for business purposes is an important measure for deepening the reform of the rural land system,promoting the flow of urban and rural factors,and realizing rural revitalization.Since the production of the first batch of pilot projects in 2015,33 county-level cities have participated in the pilot policy by 2023.Deqing County,Zhejiang Province,as the first area to participate in the pilot project,aims to achieve more fruitful results.This paper first examines how promoting farmers’income through the market entry of agricultural land can be achieved,then uses the synthetic control method to quantitatively study the impact of collective operational construction land on farmers’income using panel data from 2011 to 2019,and finally proposes relevant suggestions from the perspective of system reform.展开更多
The representative collective digital signature,which was suggested by us,is built based on combining the advantages of group digital signature and collective digital signature.This collective digital signature schema...The representative collective digital signature,which was suggested by us,is built based on combining the advantages of group digital signature and collective digital signature.This collective digital signature schema helps to create a unique digital signature that deputizes a collective of people representing different groups of signers and may also include personal signers.The advantage of the proposed collective signature is that it can be built based on most of the well-known difficult problems such as the factor analysis,the discrete logarithm and finding modulo roots of large prime numbers and the current digital signature standards of the United States and Russian Federation.In this paper,we use the discrete logarithmic problem on prime finite fields,which has been implemented in the GOST R34.10-1994 digital signature standard,to build the proposed collective signature protocols.These protocols help to create collective signatures:Guaranteed internal integrity and fixed size,independent of the number of members involved in forming the signature.The signature built in this study,consisting of 3 components(U,R,S),stores the information of all relevant signers in the U components,thus tracking the signer and against the“disclaim of liability”of the signer later is possible.The idea of hiding the signer’s public key is also applied in the proposed protocols.This makes it easy for the signing group representative to specify which members are authorized to participate in the signature creation process.展开更多
In this study, the rapidity distribution, collective flows, and nuclear stopping power in ^(197)Au+^(197)Au collisions at intermediate energies were investigated using the ultrarelativistic quantum molecular dynamics(...In this study, the rapidity distribution, collective flows, and nuclear stopping power in ^(197)Au+^(197)Au collisions at intermediate energies were investigated using the ultrarelativistic quantum molecular dynamics(UrQMD) model with GEMINI++ code. The UrQMD model was adopted to simulate the dynamic evolution of heavy-ion collisions, whereas the GEMINI++ code was used to simulate the decay of primary fragments produced by UrQMD. The calculated results were compared with the INDRA and FOPI experimental data. It was found that the rapidity distribution, collective flows, and nuclear stopping power were affected to a certain extent by the decay of primary fragments, especially at lower beam energies. Furthermore, the experimental data of the collective flows and nuclear stopping power at the investigated beam energies were better reproduced when the sequential decay effect was included.展开更多
In the past few decades, the study of collective motion phase transition process has made great progress. It is also important for the description of the spatial distribution of particles. In this work, we propose a n...In the past few decades, the study of collective motion phase transition process has made great progress. It is also important for the description of the spatial distribution of particles. In this work, we propose a new order parameter φ to quantify the degree of order in the spatial distribution of particles. The results show that the spatial distribution order parameter can effectively describe the transition from a disorderly moving phase to a phase with a coherent motion of the particle distribution and the same conclusion could be obtained for systems with different sizes. Furthermore, we develop a powerful molecular dynamic graph network(MDGNet) model to realize the long-term prediction of the self-propelled collective system solely from the initial particle positions and movement angles. Employing this model, we successfully predict the order parameters of the specified time step. And the model can also be applied to analyze other types of complex systems with local interactions.展开更多
The first laser–plasma interaction experiment using lasers of eight beams grouped into one octad has been conducted on the Shenguang Octopus facility.Although each beam intensity is below its individual threshold for...The first laser–plasma interaction experiment using lasers of eight beams grouped into one octad has been conducted on the Shenguang Octopus facility.Although each beam intensity is below its individual threshold for stimulated Brillouin backscattering(SBS),collective behaviors are excited to enhance the octad SBS.In particular,when two-color/cone lasers with wavelength separation 0.3 nm are used,the backward SBS reflectivities show novel behavior in which beams of longer wavelength achieve higher SBS gain.This property of SBS can be attributed to the rotation of the wave vectors of common ion acoustic waves due to the competition of detunings between geometrical angle and wavelength separation.This mechanism is confirmed using massively parallel supercomputer simulations with the three-dimensional laser–plasma interaction code LAP3D.展开更多
As a promising method for fast ion diagnostics,collective Thomson scattering(CTS)can measure the one-dimensional velocity distribution of fast ions with high spatial and temporal resolution.The feasibility of diagnosi...As a promising method for fast ion diagnostics,collective Thomson scattering(CTS)can measure the one-dimensional velocity distribution of fast ions with high spatial and temporal resolution.The feasibility of diagnosing fast ions in a compact high-field tokamak by CTS was studied in this work,and the results showed that a wide range of probing frequencies could be applied.A high-frequency case and a low-frequency case were mainly considered for fast ion diagnostics in a compact high-field tokamak.The use of a high probing frequency could effectively avoid the refraction effect of the beams,while the application of a low probing frequency allows greater flexibility in the selection of scattering angle which may help to improve the spatial resolution.Based on typical plasma conditions(B_(0)=12.2 T,n_(e0)=4.3×10^(20)m^(-3),T_(e0)=22.2 keV,T_(i0)=19.8 keV)for a compact high-field tokamak,a220 GHz CTS diagnostic that utilizes a small scattering angle ofθ=30°and a 160 GHz CTS diagnostic that utilizes an orthogonal geometry were proposed.Further study showed that the high-frequency case could operate in a wider range of plasma conditions and provide more information on fast ions while the low-frequency case could achieve higher spatial resolution of the poloidal direction.展开更多
Collective cancer cell migration(CCCM)and epithelial-to-mesenchymal transition(EMT)play key roles in metastasis.This study reports that the colorectal carcinoma cell line LIM1863 is useful for the study of CCCM and EM...Collective cancer cell migration(CCCM)and epithelial-to-mesenchymal transition(EMT)play key roles in metastasis.This study reports that the colorectal carcinoma cell line LIM1863 is useful for the study of CCCM and EMT.Methods:Hematoxylin and eosin staining,scanning electron microscopy,transmission electron microscopy,and western blot analysis were performed.Results:LIM1863 automatically grew as spheroids in suspension and had important typical epithelial properties,including several layers of cells arranged around a central lumen,apical-basal polarity,and types of cell-cell junctions.Treatment with a combination of both TGF beta 1 and TNF alpha induced definite and distinct EMT,a spheroid changing phenotype to form a monolayer high-confluent patch without lumen,without polarity.Spontaneous CCCM occurred in spheroids.Flat EMT cells adhered to the base of a dish,exhibited persistent movement as a cluster of cells,and then shed,resulting in a cluster.All cells from one cluster undergoing CCCM died.Otherwise,all cells undergoing EMT disappeared and almost all cells located in the cell reservoir survived and proliferated.Conclusion:LIM1863 is an excellent cell line to study CCCM and EMT.The group of heterogeneous cells undergoing CCCM behaves like a supracellular unit.展开更多
In this paper,based on the process data of evaluating the benchmark land prices of collective construction land and agricultural land,the score of influencing factors is calculated,and a regression model between value...In this paper,based on the process data of evaluating the benchmark land prices of collective construction land and agricultural land,the score of influencing factors is calculated,and a regression model between value-added benefits and influencing factors is established.According to the contribution of the government and collectives to value-added benefits,the distribution proportions of different purposes and levels are calculated.The research results show that there are significant differences in the distribution proportion of value-added income among different levels.The government distribution proportion decreases with the decrease of level,while the collective distribution proportion increases with the decrease of level.For each level of decrease in commercial service industry land and industrial and mining warehousing industry land,the government distribution proportion decreases by an average of 2.66%and 2.34%,while the collective distribution proportion increases by an average of 2.66%and 2.34%,respectively.The average distribution proportion of the government in the value-added income of commercial service industry land is 31.58%,which is much higher than the average income of 23.68%in the value-added income of industrial and mining warehousing industry land.展开更多
Based on the analysis of financial statements,the performance and problems of rural collective economic organizations in their business activities were analyzed.It is believed that rural collective economy was develop...Based on the analysis of financial statements,the performance and problems of rural collective economic organizations in their business activities were analyzed.It is believed that rural collective economy was developing continuously in a good way,with strong debt paying ability,but the operation ability and management efficiency need to be further improved.The operation was too conservative,and the asset utilization efficiency and profitability were weak.There were many unnecessary liabilities,and they developed mainly relying on their own accumulation.Therefore,it is proposed to crack the"talent dilemma"of rural collective economic operation and management,straighten out and clarify the relationship between rural collective economic organizations and villagers self-governing organizations,correctly handle the relationship between collective accumulation and member distribution,adhere to the financial input of blood replenishment and transfusion,and make liabilities reasonable according to the management development.展开更多
In this article I aim to highlight the question how to negotiate and reconstruct new identities among previously perpetuator groups in the trauma zones by looking at a specific case example,Bosnia-Herzegovina(BiH)and ...In this article I aim to highlight the question how to negotiate and reconstruct new identities among previously perpetuator groups in the trauma zones by looking at a specific case example,Bosnia-Herzegovina(BiH)and Bosnian Serbs.After the end of the Bosnian war(1992-1995)through Dayton Peace Accord,Bosnian Serbs have been started to be classified as the perpetuator group of the war.However,both Bosniaks,the main victim ethnic group of the war,and Bosnian Serbs have also started to draw the borders of Serbness into different boundaries,such as moral and religious ones.In this study I employed the method of(online)in-depth interviewing with my Bosniak and Bosnian Serb participants to underline and display which components and experiences have been shaping Bosnian Serbness since the end of the war.After the analysis of my interviews,one could argue that burden of guilt and burden of loss might have caused re-imagination of Bosnian Serbness as today’s victims.Furthermore,according to the main pattern I detected among the testimonies of my participants,one could also argue that exclusion of Bosnian Serbs due to their ethnicity from everyday tasks or rituals makes their another supreme identity much more visible:they are Christian Orthodoxies of Bosnia now.展开更多
The purpose of this study is to determine the effect of collective bargaining on employee motivation in the Zimbabwean gold mining sector.The continued restless among employees at various gold mines in the midlands pr...The purpose of this study is to determine the effect of collective bargaining on employee motivation in the Zimbabwean gold mining sector.The continued restless among employees at various gold mines in the midlands province has resulted in productivity levels dwindling.There has been increased labour turnover by employees as well as increased union representation to management.Questionnaire were used to collect data.In this article a population of one thousand employees was used.A sample of two hundred employees was selected across the board.The results of the study indicate positive relationships between collective bargaining and job satisfaction among the employees in the Zimbabwean gold mining sector.Implications of these results are that the human resource interventions are required in order to create an environment in which employees can freely engage in collective bargaining.Furthermore,the results indicate that collective bargaining engenders intrinsic motivation and above all allows for the protection of employee’s rights and welfare as well as promoting industrial democracy.This study recommends that managers should guard against preventing or obstructing employees from seeking legal redress to protect their interest.In addition,labour officers should be given the right of reasonable access to workers during working hours at their organisations for the purposes of advising the workers on the law.The employees should be given a latitude to belong to a trade union and or workers committee.展开更多
A multi-user quantum key distribution protocol is proposed with single particles and the collective eavesdropping detection strategy on a star network. By utilizing this protocol, any two users of the network can acco...A multi-user quantum key distribution protocol is proposed with single particles and the collective eavesdropping detection strategy on a star network. By utilizing this protocol, any two users of the network can accomplish quantum key distribution with the help of a serving center. Due to the utilization of the collective eavesdropping detection strategy, the users of the protocol just need to have the ability of performing certain unitary operations. Furthermore, we present three fault-tolerant versions of the proposed protocol, which can combat with the errors over different collective-noise channels.The security of all the proposed protocols is guaranteed by the theorems on quantum operation discrimination.展开更多
The collective Bamiltonian up to the fourth order for multi-O（4） model is derived based on the self-consistent collective-coordinate （SCC） method, which is formulated in the framework of the time-dependent Hartree...The collective Bamiltonian up to the fourth order for multi-O（4） model is derived based on the self-consistent collective-coordinate （SCC） method, which is formulated in the framework of the time-dependent Hartree-Bogoliubov （TDHB） theory. The validity of the collective Hamiltonian is checked in the two special cases of the multi-O（4） model： the case where the number of the shells is equal to one （a single j-shell case）, and the case where the Hartree-Bogoliubov equilibrium point is spherical （the spherical case）. The collective Hamiltonian constitutes a good starting point to study nuclear shape coexistence.展开更多
In the research, reform of rural collective economy property right system in Beijing rural-urban continuum was explored in terms of background, cause, pro- cess and practice modes by surveying and interviewing, and th...In the research, reform of rural collective economy property right system in Beijing rural-urban continuum was explored in terms of background, cause, pro- cess and practice modes by surveying and interviewing, and the value of system reform on urbanization in rural areas was illustrated from the perspective of farmers who lose lands. The results showed that since reform and opening-up, disadvan- tages of collective economy property are always the fundamental cause of reform; rural-urban contradiction produced from rapid urbanization makes the reform much more urgent; shareholding co-operative system is the essence of reform of collective economy property right system. Rural collective economy property right system in Beijing includes stock-assets quantification shareholding co-operative system, share- capitalization of contractual land management right, farmers as shareholders by investment, and resource and capital mode, with advantages and disadvantages respectively. The common character should be noticed is that all modes have share on contractual right of land, indicating the core of the reform of property system lies in asset quantification and stock quota. In improving urban-rural integration and modern market system, as well as endowing more rights to farmers, reform of rural collective economy property right system is of great significance, which provides a transition space and buffer mechanism for urbanization in rural areas.展开更多
基金supported by National Key R&D Program of China(2018YFA0901700)National Natural Science Foundation of China(22278241)+1 种基金a grant from the Institute Guo Qiang,Tsinghua University(2021GQG1016)Department of Chemical Engineering-iBHE Joint Cooperation Fund.
文摘Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical work.During the last 60 years,designing molecular structures capable of generating unidirectional mechanical motion at the nanoscale has been the topic of intense research.Effective progress has been made,attributed to advances in various fields such as supramolecular chemistry,biology and nanotechnology,and informatics.However,individual molecular machines are only capable of producing nanometer work and generally have only a single functionality.In order to address these problems,collective behaviors realized by integrating several or more of these individual mechanical units in space and time have become a new paradigm.In this review,we comprehensively discuss recent developments in the collective behaviors of molecular machines.In particular,collective behavior is divided into two paradigms.One is the appropriate integration of molecular machines to efficiently amplify molecular motions and deformations to construct novel functional materials.The other is the construction of swarming modes at the supramolecular level to perform nanoscale or microscale operations.We discuss design strategies for both modes and focus on the modulation of features and properties.Subsequently,in order to address existing challenges,the idea of transferring experience gained in the field of micro/nano robotics is presented,offering prospects for future developments in the collective behavior of molecular machines.
基金This study was supported by the National Natural Science Foundation ofChina(Nos.12147106,12175072,and 11722546)the Talent Programof South China University of Technology(No.20210115).
文摘The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(LQMD.RMF). Using the LQMD.RMF, the properties of collective flow and pion production were investigated systematically for nuclear reactions with various isospin asymmetries. The directed and elliptic flows of the LQMD.RMF are able to describe the experimental data of STAR Collaboration. The directed flow difference between free neutrons and protons was associated with the stiffness of the symmetry energy, that is, a softer symmetry energy led to a larger flow difference. For various collision energies, the ratio between the π^(-) and π^(+) yields increased with a decrease in the slope parameter of the symmetry energy. When the collision energy was 270 MeV/nucleon, the single ratio of the pion transverse momentum spectra also increased with decreasing slope parameter of the symmetry energy in both nearly symmetric and neutron-rich systems.However, it is difficult to constrain the stiffness of the symmetry energy with the double ratio because of the lack of threshold energy correction on the pion production.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.72031009 and 61473338)。
文摘In the current information society, the dissemination mechanisms and evolution laws of individual or collective opinions and their behaviors are the research hot topics in the field of opinion dynamics. First, in this paper, a two-layer network consisting of an individual-opinion layer and a collective-opinion layer is constructed, and a dissemination model of opinions incorporating higher-order interactions(i.e. OIHOI dissemination model) is proposed. Furthermore, the dynamic equations of opinion dissemination for both individuals and groups are presented. Using Lyapunov's first method,two equilibrium points, including the negative consensus point and positive consensus point, and the dynamic equations obtained for opinion dissemination, are analyzed theoretically. In addition, for individual opinions and collective opinions,some conditions for reaching negative consensus and positive consensus as well as the theoretical expression for the dissemination threshold are put forward. Numerical simulations are carried to verify the feasibility and effectiveness of the proposed theoretical results, as well as the influence of the intra-structure, inter-connections, and higher-order interactions on the dissemination and evolution of individual opinions. The main results are as follows.(i) When the intra-structure of the collective-opinion layer meets certain characteristics, then a negative or positive consensus is easier to reach for individuals.(ii) Both negative consensus and positive consensus perform best in mixed type of inter-connections in the two-layer network.(iii) Higher-order interactions can quickly eliminate differences in individual opinions, thereby enabling individuals to reach consensus faster.
文摘Coinciding with World Water Day celebrations and under the slogan"Water,a shared responsibility,"the eco-efficient textile technology company,Jeanologia,calls on this productive sector,appealing for a real change,away from greenwashing and towards concrete and collective action.
文摘The entry of collective construction land for business purposes is an important measure for deepening the reform of the rural land system,promoting the flow of urban and rural factors,and realizing rural revitalization.Since the production of the first batch of pilot projects in 2015,33 county-level cities have participated in the pilot policy by 2023.Deqing County,Zhejiang Province,as the first area to participate in the pilot project,aims to achieve more fruitful results.This paper first examines how promoting farmers’income through the market entry of agricultural land can be achieved,then uses the synthetic control method to quantitatively study the impact of collective operational construction land on farmers’income using panel data from 2011 to 2019,and finally proposes relevant suggestions from the perspective of system reform.
基金supported by Duy Tan University,Da Nang,Vietnam.
文摘The representative collective digital signature,which was suggested by us,is built based on combining the advantages of group digital signature and collective digital signature.This collective digital signature schema helps to create a unique digital signature that deputizes a collective of people representing different groups of signers and may also include personal signers.The advantage of the proposed collective signature is that it can be built based on most of the well-known difficult problems such as the factor analysis,the discrete logarithm and finding modulo roots of large prime numbers and the current digital signature standards of the United States and Russian Federation.In this paper,we use the discrete logarithmic problem on prime finite fields,which has been implemented in the GOST R34.10-1994 digital signature standard,to build the proposed collective signature protocols.These protocols help to create collective signatures:Guaranteed internal integrity and fixed size,independent of the number of members involved in forming the signature.The signature built in this study,consisting of 3 components(U,R,S),stores the information of all relevant signers in the U components,thus tracking the signer and against the“disclaim of liability”of the signer later is possible.The idea of hiding the signer’s public key is also applied in the proposed protocols.This makes it easy for the signing group representative to specify which members are authorized to participate in the signature creation process.
基金partly supported by the National Natural Science Foundation of China (Nos. U2032145 and 11875125)the National Key Research and Development Program of China (No. 2020YFE0202002)。
文摘In this study, the rapidity distribution, collective flows, and nuclear stopping power in ^(197)Au+^(197)Au collisions at intermediate energies were investigated using the ultrarelativistic quantum molecular dynamics(UrQMD) model with GEMINI++ code. The UrQMD model was adopted to simulate the dynamic evolution of heavy-ion collisions, whereas the GEMINI++ code was used to simulate the decay of primary fragments produced by UrQMD. The calculated results were compared with the INDRA and FOPI experimental data. It was found that the rapidity distribution, collective flows, and nuclear stopping power were affected to a certain extent by the decay of primary fragments, especially at lower beam energies. Furthermore, the experimental data of the collective flows and nuclear stopping power at the investigated beam energies were better reproduced when the sequential decay effect was included.
基金the National Natural Science Foundation of China (Grant No. 11702289)Key core technology and generic technology research and development project of Shanxi Province of China (Grant No. 2020XXX013)the National Key Research and Development Project of China。
文摘In the past few decades, the study of collective motion phase transition process has made great progress. It is also important for the description of the spatial distribution of particles. In this work, we propose a new order parameter φ to quantify the degree of order in the spatial distribution of particles. The results show that the spatial distribution order parameter can effectively describe the transition from a disorderly moving phase to a phase with a coherent motion of the particle distribution and the same conclusion could be obtained for systems with different sizes. Furthermore, we develop a powerful molecular dynamic graph network(MDGNet) model to realize the long-term prediction of the self-propelled collective system solely from the initial particle positions and movement angles. Employing this model, we successfully predict the order parameters of the specified time step. And the model can also be applied to analyze other types of complex systems with local interactions.
基金supported by the Natural Science Foundation of China(Grant Nos.11975059,12005021,and 11875241).
文摘The first laser–plasma interaction experiment using lasers of eight beams grouped into one octad has been conducted on the Shenguang Octopus facility.Although each beam intensity is below its individual threshold for stimulated Brillouin backscattering(SBS),collective behaviors are excited to enhance the octad SBS.In particular,when two-color/cone lasers with wavelength separation 0.3 nm are used,the backward SBS reflectivities show novel behavior in which beams of longer wavelength achieve higher SBS gain.This property of SBS can be attributed to the rotation of the wave vectors of common ion acoustic waves due to the competition of detunings between geometrical angle and wavelength separation.This mechanism is confirmed using massively parallel supercomputer simulations with the three-dimensional laser–plasma interaction code LAP3D.
基金supported by the National MCF Energy R&D Program of China(No.2019YFE03020003)partly supported by the Key Research and Development Program of Hubei Province(No.2021BAA167)National Natural Science Foundation of China(No.51821005)。
文摘As a promising method for fast ion diagnostics,collective Thomson scattering(CTS)can measure the one-dimensional velocity distribution of fast ions with high spatial and temporal resolution.The feasibility of diagnosing fast ions in a compact high-field tokamak by CTS was studied in this work,and the results showed that a wide range of probing frequencies could be applied.A high-frequency case and a low-frequency case were mainly considered for fast ion diagnostics in a compact high-field tokamak.The use of a high probing frequency could effectively avoid the refraction effect of the beams,while the application of a low probing frequency allows greater flexibility in the selection of scattering angle which may help to improve the spatial resolution.Based on typical plasma conditions(B_(0)=12.2 T,n_(e0)=4.3×10^(20)m^(-3),T_(e0)=22.2 keV,T_(i0)=19.8 keV)for a compact high-field tokamak,a220 GHz CTS diagnostic that utilizes a small scattering angle ofθ=30°and a 160 GHz CTS diagnostic that utilizes an orthogonal geometry were proposed.Further study showed that the high-frequency case could operate in a wider range of plasma conditions and provide more information on fast ions while the low-frequency case could achieve higher spatial resolution of the poloidal direction.
基金supported by Hebei Province Key Research and Development Program(19277770D)Natural Science Foundation of Hebei Province(H2018423026)+2 种基金the Foundation of Health and Family Planning Commission of Hebei(2018068620180688)Fund of Hebei Administration of Traditional Chinese Medicine(2023020).
文摘Collective cancer cell migration(CCCM)and epithelial-to-mesenchymal transition(EMT)play key roles in metastasis.This study reports that the colorectal carcinoma cell line LIM1863 is useful for the study of CCCM and EMT.Methods:Hematoxylin and eosin staining,scanning electron microscopy,transmission electron microscopy,and western blot analysis were performed.Results:LIM1863 automatically grew as spheroids in suspension and had important typical epithelial properties,including several layers of cells arranged around a central lumen,apical-basal polarity,and types of cell-cell junctions.Treatment with a combination of both TGF beta 1 and TNF alpha induced definite and distinct EMT,a spheroid changing phenotype to form a monolayer high-confluent patch without lumen,without polarity.Spontaneous CCCM occurred in spheroids.Flat EMT cells adhered to the base of a dish,exhibited persistent movement as a cluster of cells,and then shed,resulting in a cluster.All cells from one cluster undergoing CCCM died.Otherwise,all cells undergoing EMT disappeared and almost all cells located in the cell reservoir survived and proliferated.Conclusion:LIM1863 is an excellent cell line to study CCCM and EMT.The group of heterogeneous cells undergoing CCCM behaves like a supracellular unit.
文摘In this paper,based on the process data of evaluating the benchmark land prices of collective construction land and agricultural land,the score of influencing factors is calculated,and a regression model between value-added benefits and influencing factors is established.According to the contribution of the government and collectives to value-added benefits,the distribution proportions of different purposes and levels are calculated.The research results show that there are significant differences in the distribution proportion of value-added income among different levels.The government distribution proportion decreases with the decrease of level,while the collective distribution proportion increases with the decrease of level.For each level of decrease in commercial service industry land and industrial and mining warehousing industry land,the government distribution proportion decreases by an average of 2.66%and 2.34%,while the collective distribution proportion increases by an average of 2.66%and 2.34%,respectively.The average distribution proportion of the government in the value-added income of commercial service industry land is 31.58%,which is much higher than the average income of 23.68%in the value-added income of industrial and mining warehousing industry land.
基金Supported by the Scientific Research Project for College Students of Hubei University of Economics in 2022.
文摘Based on the analysis of financial statements,the performance and problems of rural collective economic organizations in their business activities were analyzed.It is believed that rural collective economy was developing continuously in a good way,with strong debt paying ability,but the operation ability and management efficiency need to be further improved.The operation was too conservative,and the asset utilization efficiency and profitability were weak.There were many unnecessary liabilities,and they developed mainly relying on their own accumulation.Therefore,it is proposed to crack the"talent dilemma"of rural collective economic operation and management,straighten out and clarify the relationship between rural collective economic organizations and villagers self-governing organizations,correctly handle the relationship between collective accumulation and member distribution,adhere to the financial input of blood replenishment and transfusion,and make liabilities reasonable according to the management development.
文摘In this article I aim to highlight the question how to negotiate and reconstruct new identities among previously perpetuator groups in the trauma zones by looking at a specific case example,Bosnia-Herzegovina(BiH)and Bosnian Serbs.After the end of the Bosnian war(1992-1995)through Dayton Peace Accord,Bosnian Serbs have been started to be classified as the perpetuator group of the war.However,both Bosniaks,the main victim ethnic group of the war,and Bosnian Serbs have also started to draw the borders of Serbness into different boundaries,such as moral and religious ones.In this study I employed the method of(online)in-depth interviewing with my Bosniak and Bosnian Serb participants to underline and display which components and experiences have been shaping Bosnian Serbness since the end of the war.After the analysis of my interviews,one could argue that burden of guilt and burden of loss might have caused re-imagination of Bosnian Serbness as today’s victims.Furthermore,according to the main pattern I detected among the testimonies of my participants,one could also argue that exclusion of Bosnian Serbs due to their ethnicity from everyday tasks or rituals makes their another supreme identity much more visible:they are Christian Orthodoxies of Bosnia now.
文摘The purpose of this study is to determine the effect of collective bargaining on employee motivation in the Zimbabwean gold mining sector.The continued restless among employees at various gold mines in the midlands province has resulted in productivity levels dwindling.There has been increased labour turnover by employees as well as increased union representation to management.Questionnaire were used to collect data.In this article a population of one thousand employees was used.A sample of two hundred employees was selected across the board.The results of the study indicate positive relationships between collective bargaining and job satisfaction among the employees in the Zimbabwean gold mining sector.Implications of these results are that the human resource interventions are required in order to create an environment in which employees can freely engage in collective bargaining.Furthermore,the results indicate that collective bargaining engenders intrinsic motivation and above all allows for the protection of employee’s rights and welfare as well as promoting industrial democracy.This study recommends that managers should guard against preventing or obstructing employees from seeking legal redress to protect their interest.In addition,labour officers should be given the right of reasonable access to workers during working hours at their organisations for the purposes of advising the workers on the law.The employees should be given a latitude to belong to a trade union and or workers committee.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61272057,61170270,and 61309029)Beijing Higher Education Young Elite Teacher Project,China(Grant Nos.YETP0475 and YETP0477)BUPT Excellent Ph.D.Students Foundation,China(Grant No.CX201441)
文摘A multi-user quantum key distribution protocol is proposed with single particles and the collective eavesdropping detection strategy on a star network. By utilizing this protocol, any two users of the network can accomplish quantum key distribution with the help of a serving center. Due to the utilization of the collective eavesdropping detection strategy, the users of the protocol just need to have the ability of performing certain unitary operations. Furthermore, we present three fault-tolerant versions of the proposed protocol, which can combat with the errors over different collective-noise channels.The security of all the proposed protocols is guaranteed by the theorems on quantum operation discrimination.
基金The project supported by the Director Foundation from the Department of Nuclear Physics of China Institute of Atomic Energy under Grant Nos. 11SZZ200501 and 11SZZ200601 0ne of the authors （J.Z. Gu） is grateful to H. Aiba, K. Hagino, K. Matsuyanagi, S. Mizutori, F. Sakata, and Y.Z. Zhuo for valuable discussions on this subject. He also acknowledges support from Postdoctoral Fellowship for Foreign Researchers of the Japan Society for the Promotion of Science with thanks.
文摘The collective Bamiltonian up to the fourth order for multi-O（4） model is derived based on the self-consistent collective-coordinate （SCC） method, which is formulated in the framework of the time-dependent Hartree-Bogoliubov （TDHB） theory. The validity of the collective Hamiltonian is checked in the two special cases of the multi-O（4） model： the case where the number of the shells is equal to one （a single j-shell case）, and the case where the Hartree-Bogoliubov equilibrium point is spherical （the spherical case）. The collective Hamiltonian constitutes a good starting point to study nuclear shape coexistence.
基金Supported by Major Project of the National Social Science Fund(13&ZD027)National Natural Science Foundation of China(41371177)the National Science and Technology Support Planning(2012BAJ22B03)~~
文摘In the research, reform of rural collective economy property right system in Beijing rural-urban continuum was explored in terms of background, cause, pro- cess and practice modes by surveying and interviewing, and the value of system reform on urbanization in rural areas was illustrated from the perspective of farmers who lose lands. The results showed that since reform and opening-up, disadvan- tages of collective economy property are always the fundamental cause of reform; rural-urban contradiction produced from rapid urbanization makes the reform much more urgent; shareholding co-operative system is the essence of reform of collective economy property right system. Rural collective economy property right system in Beijing includes stock-assets quantification shareholding co-operative system, share- capitalization of contractual land management right, farmers as shareholders by investment, and resource and capital mode, with advantages and disadvantages respectively. The common character should be noticed is that all modes have share on contractual right of land, indicating the core of the reform of property system lies in asset quantification and stock quota. In improving urban-rural integration and modern market system, as well as endowing more rights to farmers, reform of rural collective economy property right system is of great significance, which provides a transition space and buffer mechanism for urbanization in rural areas.
