Model checking is crucial in statistical analyses and has garnered significant attention in the academic literature.However,certain challenges persist in scenarios that involve large-scale datasets and limited resourc...Model checking is crucial in statistical analyses and has garnered significant attention in the academic literature.However,certain challenges persist in scenarios that involve large-scale datasets and limited resource allocations.This research introduces a novel subsampling methodology for testing regression models with continuous and categorical predictors,referred to as the Subsampling Adaptive Projection-Test(SAPT).This innovative approach demonstrates substantial improvements in test power for both local and global alternatives,outperforming conventional uniform subsampling mechanisms.The authors rigorously establish the asymptotic properties of SAPT and delineate its maximum achievable power under asymptotic conditions.Comprehensive simulations and real-world dataset applications provide robust validation of the proposed theoretical propositions.展开更多
In this note,the authors revisit the envelope dimension reduction,which was first introduced for estimating a sufficient dimension reduction subspace without inverting the sample covariance.Motivated by the recent dev...In this note,the authors revisit the envelope dimension reduction,which was first introduced for estimating a sufficient dimension reduction subspace without inverting the sample covariance.Motivated by the recent developments in envelope methods and algorithms,the authors refresh the envelope inverse regression as a flexible alternative to the existing inverse regression methods in dimension reduction.The authors discuss the versatility of the envelope approach and demonstrate the advantages of the envelope dimension reduction through simulation studies.展开更多
The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors...The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors,an asymptotic test is proposed under the normality assumption of the predictors as well as an asymmetry assumption about the unknown regression mean function.When these assumptions are violated,the asymptotic test with elliptical trimming and clustering is still valid with desirable numerical performances.展开更多
Classical linear discriminant analysis(LDA)(Fisher,1936)implicitly assumes the classification boundary depends on only one linear combination of the predictors.This restriction can lead to poor classification in appli...Classical linear discriminant analysis(LDA)(Fisher,1936)implicitly assumes the classification boundary depends on only one linear combination of the predictors.This restriction can lead to poor classification in applications where the decision boundary depends on multiple linear combinations of the predictors.To overcome this challenge,the authors first project the predictors onto an envelope central space and then perform LDA based on the sufficient predictor.The performance of the proposed method in improving classification accuracy is demonstrated in both synthetic data and real applications.展开更多
In this paper,the authors propose a nonlinear dimension reduction technique based on Fréchet inverse regression to achieve sufficient dimension reduction for responses in metric spaces and predictors in Riemannia...In this paper,the authors propose a nonlinear dimension reduction technique based on Fréchet inverse regression to achieve sufficient dimension reduction for responses in metric spaces and predictors in Riemannian manifolds.The authors rigorously establish statistical properties of the estimators,providing formal proofs of their consistency and asymptotic behaviors.The effectiveness of our method is demonstrated through extensive simulations and applications to real-world datasets which highlight its practical utility for complex data with non-Euclidean structures.展开更多
Multi-dimensional arrays are referred to as tensors.Tensor-valued predictors are commonly encountered in modern biomedical applications,such as electroencephalogram(EEG),magnetic resonance imaging(MRI),functional MRI(...Multi-dimensional arrays are referred to as tensors.Tensor-valued predictors are commonly encountered in modern biomedical applications,such as electroencephalogram(EEG),magnetic resonance imaging(MRI),functional MRI(fMRI),diffusion-weighted MRI,and longitudinal health data.In survival analysis,it is both important and challenging to integrate clinically relevant information,such as gender,age,and disease state along with medical imaging tensor data or longitudinal health data to predict disease outcomes.Most existing higher-order sufficient dimension reduction regressions for matrix-or array-valued data focus solely on tensor data,often neglecting established clinical covariates that are readily available and known to have predictive value.Based on the idea of Folded-Minimum Average Variance Estimation(Folded-MAVE:Xue and Yin,2014),the authors propose a new method,Partial Dimension Folded-MAVE(PF-MAVE),to address regression mean functions with tensor-valued covariates while simultaneously incorporating clinical covariates,which are typically categorical variables.Theorems and simulation studies demonstrate the importance of incorporating these categorical clinical predictors.A survival analysis of a longitudinal study of primary biliary cirrhosis(PBC)data is included for illustration of the proposed method.展开更多
In this paper,we propose a three-term conjugate gradient method for solving unconstrained optimization problems based on the Hestenes-Stiefel(HS)conjugate gradient method and Polak-Ribiere-Polyak(PRP)conjugate gradien...In this paper,we propose a three-term conjugate gradient method for solving unconstrained optimization problems based on the Hestenes-Stiefel(HS)conjugate gradient method and Polak-Ribiere-Polyak(PRP)conjugate gradient method.Under the condition of standard Wolfe line search,the proposed search direction is the descent direction.For general nonlinear functions,the method is globally convergent.Finally,numerical results show that the proposed method is efficient.展开更多
Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face...Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face multiple faults,including the unexpected controller disconnect,the temporary mismatch between subsystems and desired corresponding controllers,and the intermittent disordering of mode transitions.These commonly arising faults may result in severe and detrimental impacts on the reliability and convergence of the closed-loop solution,thereby bringing significant yet challenging issues to be tackled.This paper provides the first attempt to investigate the stabilization problem for a class of constrained switched linear systems with multiple faults under mode-dependent dwell time(MDT).From a set-theory perspective,we demonstrate a critical necessary and sufficient stability condition for switched systems without uncertainties.Moreover,the non-conservative stability criterion is further extended to the perturbed switched systems with rigorous proof.A switching communication network example verifies the validity of the theoretical result and demonstrates their advantages.展开更多
Dear Editor,Active magnetic bearings(AMBs)are of considerable interest and significance in smart manufacturing due to their zero-friction and adaptivity to noncontact rotor rotations.This paper proposes an active levi...Dear Editor,Active magnetic bearings(AMBs)are of considerable interest and significance in smart manufacturing due to their zero-friction and adaptivity to noncontact rotor rotations.This paper proposes an active levitation control algorithm based on adaptive sliding mode control(ASMC)equipped with linear extended state observer(LESO).Sufficient conditions are derived to guarantee the asymptotical stability of the associated closed-loop system.Experiments are conducted on a real AMB-rotor platform to demonstrate the effectiveness and superiority of the proposed algorithm.展开更多
Hanson and Mond have grven sets of necessary and sufficient conditions for optimality in constrained optimization by introducing classes of generalized functions, called type Ⅰ functions. Recently, Bector definded un...Hanson and Mond have grven sets of necessary and sufficient conditions for optimality in constrained optimization by introducing classes of generalized functions, called type Ⅰ functions. Recently, Bector definded univex functions, a new class of functions that unifies several concepts of generalized convexity. In this paper, additional conditions are attached to the Kuhn Tucker conditions giving a set of conditions which are both necessary and sufficient for optimality in constrained optimization, under appropriate constraint qualifications.展开更多
Mathematical models for burden descending process have been applied to obtain whole burden structures in blast furnace,whereas the accuracy of those burden descent models has not been sufficiently investigated.Special...Mathematical models for burden descending process have been applied to obtain whole burden structures in blast furnace,whereas the accuracy of those burden descent models has not been sufficiently investigated.Special evaluation method based on timeline burden profiles was established to quantitatively evaluate the error between experimental and modeled burden structures.Four existing burden descent models were utilized to describe the burden structure of a 1/20 scaled warm blast furnace.Input modeling conditions including initial burden profile,descending volumes in each time interval,and normalized descending velocity distribution were determined via special image processing technology.Modeled burden structures were evaluated combined with the published experimental data.It is found that all the models caught the main profile of the burden structure.Furthermore,the improved nonuniform descent model（Model IV）shows the highest level of precision especially when burden descends with unstable velocity distribution tendency.Meanwhile,the traditional nonuniform descent model（Model III）may also be desirable to model the burden descending process when the burden descending velocity presents a linear tendency.Finally,the uniform descent model（Model I）might be the first option for roughly predicting burden structure.展开更多
Back to the 1950s,Anderson revealed the absence of wave diffusion,i.e.,Anderson localization,in a sufficiently disordered media,marking the start of electron transport research in non-periodic lattices.[1]In a simplif...Back to the 1950s,Anderson revealed the absence of wave diffusion,i.e.,Anderson localization,in a sufficiently disordered media,marking the start of electron transport research in non-periodic lattices.[1]In a simplified theoretical model,one critical order parameter was proposed to determine the boundary of electron delocalization。展开更多
The Belt and Road is a concept that goes beyond the century.Whither will it take China?What kind of international order will it create?Such issues are less than sufficiently discussed by the Chinese academic circle an...The Belt and Road is a concept that goes beyond the century.Whither will it take China?What kind of international order will it create?Such issues are less than sufficiently discussed by the Chinese academic circle and can be quite confusing to the international community.Particularly,well-established American think tanks like the Centre for Strategic and International展开更多
This paper discusses chiefly the compactness of solution set of following equationswhere △ is the Laplacian in Sobolev’s sense, a;（x）,i= 0,1,…n, n≥ 3, are real square matrices of dimen-sion N×V , bounded an...This paper discusses chiefly the compactness of solution set of following equationswhere △ is the Laplacian in Sobolev’s sense, a;（x）,i= 0,1,…n, n≥ 3, are real square matrices of dimen-sion N×V , bounded and measurable in a bounded multiply connected domain Ω, the boundary S is as-sumed to be sufficiently smooth, u（x） is unknown vector, z = （x<sub>1</sub>,x<sub>2</sub>,…,x<sub>n</sub>） Ω R<sup>z</sup>,m≥1,|S<sub>1</sub>|issuperficial measure of the unit sphere of R<sup>Z</sup>, |i|=i<sub>1</sub>+ i<sub>2</sub> +… + i., △<sup>m</sup>=△(△<sup>m-1</sup>). ,（Ω）, ,（Ω）, … denote the classes of vectors or matrices whose elements belong to L,（Ω）,W,（Ω）,…. A vector or a matrix is said to be continuous differentiable, bounded and measurable if so are its ele-展开更多
We consider the existence and asymptotic behavior of singularly perturbed boundary value problem;εX″= b（X,t）X′,t ∈（0, 1）（1）X（0） =α, X（1） =β, （2）where, ε】0, is a sufficiently small parameter, b（X,t...We consider the existence and asymptotic behavior of singularly perturbed boundary value problem;εX″= b（X,t）X′,t ∈（0, 1）（1）X（0） =α, X（1） =β, （2）where, ε】0, is a sufficiently small parameter, b（X,t） is continuous in R×[0,1 ],α,βare prescribedboundary condition, and there is a function X<sub>0</sub>（t） satisfying the implicit equation b[X<sub>0</sub>（t）,t] 0t∈[0,1 ].Boundary value problem in this case is rarely studied by other mathematician, the auther has ever dis-cussed the autonomous equation corresponding the boundary value problem （1）,（2）. Generally speaking,the solution of the corresponding problem has boundary layer at each end of the time interval [0 ,1] , itsinner solution is commposed by one or several constant function, these constant is the zero point of the au-展开更多
Recent experiments have observed magnetic reconnection in laser-produced high-energy-density(HED)plasma bubbles.We perform two-dimensional(2-D)particle-in-cell(PIC)simulations to investigate magnetic reconnection betw...Recent experiments have observed magnetic reconnection in laser-produced high-energy-density(HED)plasma bubbles.We perform two-dimensional(2-D)particle-in-cell(PIC)simulations to investigate magnetic reconnection between two approaching HED plasma bubbles.It is found that the expanding velocity of the bubbles has a great influence on the process of magnetic reconnection.When the expanding velocity is small,a single X line reconnection is formed.However,when the expanding velocity is sufficiently large,we can observe a plasmoid in the vicinity of the X line.At the same time,the structures of the electromagnetic field in HED plasma reconnection are similar to that in Harris current sheet reconnection.展开更多
A one-dimensional two-layer Frenkel–Kontorova model is studied.Firstly,a feedback tracking control law is given.Then,the boundedness result for the error states of single particles of the model is derived using the L...A one-dimensional two-layer Frenkel–Kontorova model is studied.Firstly,a feedback tracking control law is given.Then,the boundedness result for the error states of single particles of the model is derived using the Lyapunov Method.Especially,the motion of single particles can be approximated analytically for the case of sufficiently large targeted velocity.Simulations illustrate the accuracy of the derived results.展开更多
1.Introduction Formulating an optimal roadmap to realizing the goals of peak carbon dioxide emissions and carbon neutrality calls for a systemic analysis of mesoscale structures at multiple levels and of their governi...1.Introduction Formulating an optimal roadmap to realizing the goals of peak carbon dioxide emissions and carbon neutrality calls for a systemic analysis of mesoscale structures at multiple levels and of their governing multiobjective mechanisms within different sectors and fields.However,the analyses currently available are mostly based on traditional approaches,which have not considered different levels of complexity and heterogeneity sufficiently,or have not accounted for multiple objectives sufficiently reasonably.In this perspective article,we attempt to figure out a new framework for dealing with this challenging issue within a totally different paradigm for multiscale complex systems,in which such a global challenge and the paradigm shift in science need to be addressed jointly.展开更多
The formation of the Moon remains obscure after＊400 years since Galileo saw that the Moon was mountainous in 1609.The current hypothesis is that the Moon formed through a low-angle collision between the Earth and Mar...The formation of the Moon remains obscure after＊400 years since Galileo saw that the Moon was mountainous in 1609.The current hypothesis is that the Moon formed through a low-angle collision between the Earth and Mar-size impactor,which is known as the Giant Impact model（e.g.Benz et al.1989）.The giant impact should be sufficiently展开更多
专利名称:Collocation of radiation generator components for limited-space devices1(中文译名:有限空间装置用辐射发生器部件的配置1)专利申请号:US201514975640申请日:2015.12.18公开号:US10116232B2公开日:2018.10.30申请人:SCHLU...专利名称:Collocation of radiation generator components for limited-space devices1(中文译名:有限空间装置用辐射发生器部件的配置1)专利申请号:US201514975640申请日:2015.12.18公开号:US10116232B2公开日:2018.10.30申请人:SCHLUMBERGER TECHNOLOGY CORP;A compact radiation generator for use in a downhole well-logging tool is disclosed.The compact radiation generator comprises a housing with a cavity,a linear acceleration tube in the cavity that generates radiation when supplied with a sufficiently high voltage,and a first voltage multiplier ladder in the cavity configured to supply the sufficiently high voltage to the acceleration tube.The first voltage multiplier ladder is folded into two linear parts that are collocated to each other.展开更多
基金supported by the National Social Science Foundation of China under Grant No.21 BT1048the National Scientific Foundation of China under Grant Nos.12371276 and 12131006。
文摘Model checking is crucial in statistical analyses and has garnered significant attention in the academic literature.However,certain challenges persist in scenarios that involve large-scale datasets and limited resource allocations.This research introduces a novel subsampling methodology for testing regression models with continuous and categorical predictors,referred to as the Subsampling Adaptive Projection-Test(SAPT).This innovative approach demonstrates substantial improvements in test power for both local and global alternatives,outperforming conventional uniform subsampling mechanisms.The authors rigorously establish the asymptotic properties of SAPT and delineate its maximum achievable power under asymptotic conditions.Comprehensive simulations and real-world dataset applications provide robust validation of the proposed theoretical propositions.
基金supported by the National Natural Science Foundation of China under Grant No.12301365supported by the National Natural Science Foundation of China under Grant No.2241200071Guangdong Basic and Applied Basic Research Foundation under Grant No.2023A1515110001。
文摘In this note,the authors revisit the envelope dimension reduction,which was first introduced for estimating a sufficient dimension reduction subspace without inverting the sample covariance.Motivated by the recent developments in envelope methods and algorithms,the authors refresh the envelope inverse regression as a flexible alternative to the existing inverse regression methods in dimension reduction.The authors discuss the versatility of the envelope approach and demonstrate the advantages of the envelope dimension reduction through simulation studies.
文摘The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors,an asymptotic test is proposed under the normality assumption of the predictors as well as an asymmetry assumption about the unknown regression mean function.When these assumptions are violated,the asymptotic test with elliptical trimming and clustering is still valid with desirable numerical performances.
文摘Classical linear discriminant analysis(LDA)(Fisher,1936)implicitly assumes the classification boundary depends on only one linear combination of the predictors.This restriction can lead to poor classification in applications where the decision boundary depends on multiple linear combinations of the predictors.To overcome this challenge,the authors first project the predictors onto an envelope central space and then perform LDA based on the sufficient predictor.The performance of the proposed method in improving classification accuracy is demonstrated in both synthetic data and real applications.
文摘In this paper,the authors propose a nonlinear dimension reduction technique based on Fréchet inverse regression to achieve sufficient dimension reduction for responses in metric spaces and predictors in Riemannian manifolds.The authors rigorously establish statistical properties of the estimators,providing formal proofs of their consistency and asymptotic behaviors.The effectiveness of our method is demonstrated through extensive simulations and applications to real-world datasets which highlight its practical utility for complex data with non-Euclidean structures.
文摘Multi-dimensional arrays are referred to as tensors.Tensor-valued predictors are commonly encountered in modern biomedical applications,such as electroencephalogram(EEG),magnetic resonance imaging(MRI),functional MRI(fMRI),diffusion-weighted MRI,and longitudinal health data.In survival analysis,it is both important and challenging to integrate clinically relevant information,such as gender,age,and disease state along with medical imaging tensor data or longitudinal health data to predict disease outcomes.Most existing higher-order sufficient dimension reduction regressions for matrix-or array-valued data focus solely on tensor data,often neglecting established clinical covariates that are readily available and known to have predictive value.Based on the idea of Folded-Minimum Average Variance Estimation(Folded-MAVE:Xue and Yin,2014),the authors propose a new method,Partial Dimension Folded-MAVE(PF-MAVE),to address regression mean functions with tensor-valued covariates while simultaneously incorporating clinical covariates,which are typically categorical variables.Theorems and simulation studies demonstrate the importance of incorporating these categorical clinical predictors.A survival analysis of a longitudinal study of primary biliary cirrhosis(PBC)data is included for illustration of the proposed method.
基金Supported by the Science and Technology Project of Guangxi(Guike AD23023002)。
文摘In this paper,we propose a three-term conjugate gradient method for solving unconstrained optimization problems based on the Hestenes-Stiefel(HS)conjugate gradient method and Polak-Ribiere-Polyak(PRP)conjugate gradient method.Under the condition of standard Wolfe line search,the proposed search direction is the descent direction.For general nonlinear functions,the method is globally convergent.Finally,numerical results show that the proposed method is efficient.
基金supported in part by the Natural Sciences and Engineering Research Council of Canada(NSERC)supported by the National Natural Science Foundation of China under Grant 62303403Zhejiang Provincial Natural Science Foundation of China under Grants LR25F030004 and LQ24F030022。
文摘Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face multiple faults,including the unexpected controller disconnect,the temporary mismatch between subsystems and desired corresponding controllers,and the intermittent disordering of mode transitions.These commonly arising faults may result in severe and detrimental impacts on the reliability and convergence of the closed-loop solution,thereby bringing significant yet challenging issues to be tackled.This paper provides the first attempt to investigate the stabilization problem for a class of constrained switched linear systems with multiple faults under mode-dependent dwell time(MDT).From a set-theory perspective,we demonstrate a critical necessary and sufficient stability condition for switched systems without uncertainties.Moreover,the non-conservative stability criterion is further extended to the perturbed switched systems with rigorous proof.A switching communication network example verifies the validity of the theoretical result and demonstrates their advantages.
基金supported in part by the National Natural Science Foundation of China(62225306,U2141235,52188102).
文摘Dear Editor,Active magnetic bearings(AMBs)are of considerable interest and significance in smart manufacturing due to their zero-friction and adaptivity to noncontact rotor rotations.This paper proposes an active levitation control algorithm based on adaptive sliding mode control(ASMC)equipped with linear extended state observer(LESO).Sufficient conditions are derived to guarantee the asymptotical stability of the associated closed-loop system.Experiments are conducted on a real AMB-rotor platform to demonstrate the effectiveness and superiority of the proposed algorithm.
文摘Hanson and Mond have grven sets of necessary and sufficient conditions for optimality in constrained optimization by introducing classes of generalized functions, called type Ⅰ functions. Recently, Bector definded univex functions, a new class of functions that unifies several concepts of generalized convexity. In this paper, additional conditions are attached to the Kuhn Tucker conditions giving a set of conditions which are both necessary and sufficient for optimality in constrained optimization, under appropriate constraint qualifications.
基金Item Sponsored by National Natural Science Foundation of China(61290325)
文摘Mathematical models for burden descending process have been applied to obtain whole burden structures in blast furnace,whereas the accuracy of those burden descent models has not been sufficiently investigated.Special evaluation method based on timeline burden profiles was established to quantitatively evaluate the error between experimental and modeled burden structures.Four existing burden descent models were utilized to describe the burden structure of a 1/20 scaled warm blast furnace.Input modeling conditions including initial burden profile,descending volumes in each time interval,and normalized descending velocity distribution were determined via special image processing technology.Modeled burden structures were evaluated combined with the published experimental data.It is found that all the models caught the main profile of the burden structure.Furthermore,the improved nonuniform descent model（Model IV）shows the highest level of precision especially when burden descends with unstable velocity distribution tendency.Meanwhile,the traditional nonuniform descent model（Model III）may also be desirable to model the burden descending process when the burden descending velocity presents a linear tendency.Finally,the uniform descent model（Model I）might be the first option for roughly predicting burden structure.
文摘Back to the 1950s,Anderson revealed the absence of wave diffusion,i.e.,Anderson localization,in a sufficiently disordered media,marking the start of electron transport research in non-periodic lattices.[1]In a simplified theoretical model,one critical order parameter was proposed to determine the boundary of electron delocalization。
文摘The Belt and Road is a concept that goes beyond the century.Whither will it take China?What kind of international order will it create?Such issues are less than sufficiently discussed by the Chinese academic circle and can be quite confusing to the international community.Particularly,well-established American think tanks like the Centre for Strategic and International
文摘This paper discusses chiefly the compactness of solution set of following equationswhere △ is the Laplacian in Sobolev’s sense, a;（x）,i= 0,1,…n, n≥ 3, are real square matrices of dimen-sion N×V , bounded and measurable in a bounded multiply connected domain Ω, the boundary S is as-sumed to be sufficiently smooth, u（x） is unknown vector, z = （x<sub>1</sub>,x<sub>2</sub>,…,x<sub>n</sub>） Ω R<sup>z</sup>,m≥1,|S<sub>1</sub>|issuperficial measure of the unit sphere of R<sup>Z</sup>, |i|=i<sub>1</sub>+ i<sub>2</sub> +… + i., △<sup>m</sup>=△(△<sup>m-1</sup>). ,（Ω）, ,（Ω）, … denote the classes of vectors or matrices whose elements belong to L,（Ω）,W,（Ω）,…. A vector or a matrix is said to be continuous differentiable, bounded and measurable if so are its ele-
文摘We consider the existence and asymptotic behavior of singularly perturbed boundary value problem;εX″= b（X,t）X′,t ∈（0, 1）（1）X（0） =α, X（1） =β, （2）where, ε】0, is a sufficiently small parameter, b（X,t） is continuous in R×[0,1 ],α,βare prescribedboundary condition, and there is a function X<sub>0</sub>（t） satisfying the implicit equation b[X<sub>0</sub>（t）,t] 0t∈[0,1 ].Boundary value problem in this case is rarely studied by other mathematician, the auther has ever dis-cussed the autonomous equation corresponding the boundary value problem （1）,（2）. Generally speaking,the solution of the corresponding problem has boundary layer at each end of the time interval [0 ,1] , itsinner solution is commposed by one or several constant function, these constant is the zero point of the au-
基金the National Natural Science Foundation of China under Grant Nos 11220101002,41174124,41274144 and 41121003the Key Research Program of Chinese Academy of Sciences(KZZD-EW-01)+1 种基金the National Basic Research Program of China(2012CB825602)the Ocean Public Welfare Scientific Research Project,State Oceanic Administration of China(No 201005017).
文摘Recent experiments have observed magnetic reconnection in laser-produced high-energy-density(HED)plasma bubbles.We perform two-dimensional(2-D)particle-in-cell(PIC)simulations to investigate magnetic reconnection between two approaching HED plasma bubbles.It is found that the expanding velocity of the bubbles has a great influence on the process of magnetic reconnection.When the expanding velocity is small,a single X line reconnection is formed.However,when the expanding velocity is sufficiently large,we can observe a plasmoid in the vicinity of the X line.At the same time,the structures of the electromagnetic field in HED plasma reconnection are similar to that in Harris current sheet reconnection.
基金by the U.S.National Science Foundation under Grant No CMMI 0825613.
文摘A one-dimensional two-layer Frenkel–Kontorova model is studied.Firstly,a feedback tracking control law is given.Then,the boundedness result for the error states of single particles of the model is derived using the Lyapunov Method.Especially,the motion of single particles can be approximated analytically for the case of sufficiently large targeted velocity.Simulations illustrate the accuracy of the derived results.
基金We appreciate the financial support from the Strategic Priority Research Program of Chinese Academy of Sciences(XDA21010102)the Science Challenge Project(TZ2018001)the International Partnership Program of Chinese Academy of Sciences(122111KYSB20170068).
文摘1.Introduction Formulating an optimal roadmap to realizing the goals of peak carbon dioxide emissions and carbon neutrality calls for a systemic analysis of mesoscale structures at multiple levels and of their governing multiobjective mechanisms within different sectors and fields.However,the analyses currently available are mostly based on traditional approaches,which have not considered different levels of complexity and heterogeneity sufficiently,or have not accounted for multiple objectives sufficiently reasonably.In this perspective article,we attempt to figure out a new framework for dealing with this challenging issue within a totally different paradigm for multiscale complex systems,in which such a global challenge and the paradigm shift in science need to be addressed jointly.
文摘The formation of the Moon remains obscure after＊400 years since Galileo saw that the Moon was mountainous in 1609.The current hypothesis is that the Moon formed through a low-angle collision between the Earth and Mar-size impactor,which is known as the Giant Impact model（e.g.Benz et al.1989）.The giant impact should be sufficiently
文摘专利名称:Collocation of radiation generator components for limited-space devices1(中文译名:有限空间装置用辐射发生器部件的配置1)专利申请号:US201514975640申请日:2015.12.18公开号:US10116232B2公开日:2018.10.30申请人:SCHLUMBERGER TECHNOLOGY CORP;A compact radiation generator for use in a downhole well-logging tool is disclosed.The compact radiation generator comprises a housing with a cavity,a linear acceleration tube in the cavity that generates radiation when supplied with a sufficiently high voltage,and a first voltage multiplier ladder in the cavity configured to supply the sufficiently high voltage to the acceleration tube.The first voltage multiplier ladder is folded into two linear parts that are collocated to each other.
