Let f be a primitive holomorphic cusp form with even integral weight k≥2 for the full modular groupΓ=SL(2,Z)andλ_(sym^(j)f)(n)be the n-th coefficient of Dirichlet series of j-th symmetric L-function L(s,sym^(j)f)at...Let f be a primitive holomorphic cusp form with even integral weight k≥2 for the full modular groupΓ=SL(2,Z)andλ_(sym^(j)f)(n)be the n-th coefficient of Dirichlet series of j-th symmetric L-function L(s,sym^(j)f)attached to f.In this paper,we study the mean value distribution over a specific sparse sequence of positive integers of the following sum∑(a^(2)+b^(2)+c^(2)+d^(2)≤x(a,b,c,d)∈Z^(4))λ_(sym^(j))^(i)f(a^(2)+b^(2)+c^(2)+d^(2))where j≥2 is a given positive integer,i=2,3,4 andαis sufficiently large.We utilize Python programming to design algorithms for higher power conditions,combining Perron's formula,latest results of representations of natural integers as sums of squares,as well as analytic properties and subconvexity and convexity bounds of automorphic L-functions,to ensure the accuracy and verifiability of asymptotic formulas.The conclusion we obtained improves previous results and extends them to a more general settings.展开更多
With the rapid development of modern science and technology,the era of artificial intelligence has quietly come.Against the background of the new era,students’learning needs,learning resource acquisition methods,teac...With the rapid development of modern science and technology,the era of artificial intelligence has quietly come.Against the background of the new era,students’learning needs,learning resource acquisition methods,teachers’teaching concepts,teaching tools,and so on have changed significantly.How to carry out teaching reform based on this change has become one of the important issues facing educators,and the same is true for the teaching of computer programming courses.This paper focuses on the teaching reform of AI-enabled computer programming courses,analyzes its basic problems,and puts forward corresponding reform countermeasures to provide a useful reference for front-line teachers.展开更多
As one of the core courses for computer-related majors,the Python programming course has become increasingly important in the era of artificial intelligence.It aims to help students develop good computer thinking and ...As one of the core courses for computer-related majors,the Python programming course has become increasingly important in the era of artificial intelligence.It aims to help students develop good computer thinking and improve their abilities in programming and data analysis.The application of artificial intelligence technology in the teaching of Python programming courses is of great significance for optimizing the allocation of teaching resources,enriching students’learning experience,and significantly improving teaching quality.Based on this,this paper first briefly expounds on the importance of applying artificial intelligence technology in the teaching of Python programming courses.On this basis,it focuses on exploring effective strategies for the teaching reform of Python programming courses based on artificial intelligence technology,hoping to provide new ideas for the teaching of Python programming courses and contribute to cultivating more Python programming talents with artificial intelligence literacy.展开更多
With the continuous advancement of the New Engineering Education initiative,universities are raising the standards for cultivating engineering talents.C Programming Language,as a core course for computer science and r...With the continuous advancement of the New Engineering Education initiative,universities are raising the standards for cultivating engineering talents.C Programming Language,as a core course for computer science and related majors,plays a fundamental role in developing logical thinking,programming skills,and engineering practice.However,problems such as outdated content,weak practical connections,and single assessment methods still exist in current teaching,which affects both learning outcomes and students’skill development.Based on the outcome-based education(OBE)approach and supported by AI-assisted teaching tools,this paper proposes a reform plan focusing on teaching content,instructional methods,and evaluation systems.The goal is to enhance students’overall abilities and practical innovation skills,and to align the course more closely with modern industry needs.展开更多
Objective:To investigate the application effect of the SECI theoretical model-based training program in enhancing clinical nursing teachers‘information-based teaching capabilities.Methods:A self-control study design ...Objective:To investigate the application effect of the SECI theoretical model-based training program in enhancing clinical nursing teachers‘information-based teaching capabilities.Methods:A self-control study design was adopted,with 124 clinical nursing teachers from a tertiary hospital participating in the SECI training program from January 2024 to June 2025.The program was implemented through four stages:“Establishing Teacher Community(Socialization)”,“Case Teaching(Extravagant)”,“Integration of Discipline and Research(Fusion)”,and“Routine Application of Teaching(Implicit)”.Self-designed questionnaires were used to assess teachers’information-based teaching capabilities before and after training,covering four dimensions:awareness and attitude towards information-based teaching,foundational skills,teaching practice,and professional practice.Data analysis was performed using SPSS 26.0.Results:Post-training,the total score of clinical nursing teachers’information-based teaching capabilities increased from(53.47±15.56)to(78.92±12.34),showing statistically significant differences(t=15.732,P<0.001).Scores in all dimensions also showed significant improvements(P<0.05).Multivariate linear regression analysis revealed that educational background(β=0.198,P=0.026)and professional title(β=0.184,P=0.040)were primary influencing factors for pre-training information-based teaching capabilities,while their impact weakened post-training.Conclusion:The training program based on SECI theory effectively enhances clinical nursing educators’digital teaching capabilities.Its structured,spiral-up knowledge transformation process helps bridge competency gaps among teachers from diverse backgrounds,facilitates the mutual conversion and deep integration of tacit and explicit knowledge,and provides a practical new model for developing digital teaching competencies in clinical nursing education.展开更多
In this paper,a distributed adaptive dynamic programming(ADP)framework based on value iteration is proposed for multi-player differential games.In the game setting,players have no access to the information of others&#...In this paper,a distributed adaptive dynamic programming(ADP)framework based on value iteration is proposed for multi-player differential games.In the game setting,players have no access to the information of others'system parameters or control laws.Each player adopts an on-policy value iteration algorithm as the basic learning framework.To deal with the incomplete information structure,players collect a period of system trajectory data to compensate for the lack of information.The policy updating step is implemented by a nonlinear optimization problem aiming to search for the proximal admissible policy.Theoretical analysis shows that by adopting proximal policy searching rules,the approximated policies can converge to a neighborhood of equilibrium policies.The efficacy of our method is illustrated by three examples,which also demonstrate that the proposed method can accelerate the learning process compared with the centralized learning framework.展开更多
The multi-satellite electromagnetic formation flight system is nonlinear and strongly coupled,which makes modeling and optimization challenging.To simplify electromagnetic force evaluation and dynamics modeling,we int...The multi-satellite electromagnetic formation flight system is nonlinear and strongly coupled,which makes modeling and optimization challenging.To simplify electromagnetic force evaluation and dynamics modeling,we introduce a reference frame consistent with each satellite body frame,in which the electromagnetic dipoles and electromagnetic forces are represented as two-dimensional vectors.Then,the maneuver time is divided into time intervals,and different satellite sets are activated in each interval,converting the multi-satellite formation reconfiguration problem into an optimal trajectory problem of each two-satellite subsystem.To this end,a token-based dynamic programming method with a switching penalty of active satellite sets is proposed to determine the sequence of satellite sets participating in each time interval,thereby enabling all satellites to reach their desired states.For the two-satellite subsystem with the objectives of minimizing maneuver time and energy consumption,the Gauss pseudo-spectral method is employed to generate the optimal reconfiguration trajectory.Numerical simulations verify the effectiveness of the proposed optimization method.展开更多
Every year, around the world, between 250,000 and 500,000 people suffer a spinal cord injury(SCI). SCI is a devastating medical condition that arises from trauma or disease-induced damage to the spinal cord, disruptin...Every year, around the world, between 250,000 and 500,000 people suffer a spinal cord injury(SCI). SCI is a devastating medical condition that arises from trauma or disease-induced damage to the spinal cord, disrupting the neural connections that allow communication between the brain and the rest of the body, which results in varying degrees of motor and sensory impairment. Disconnection in the spinal tracts is an irreversible condition owing to the poor capacity for spontaneous axonal regeneration in the affected neurons.展开更多
Taking half-tube part with curvature as an example,the Impact Hydroforming(IHF)characteristics were studied by combining the actual forming experiment and numerical simulation.The IHF experiment showed that wrinkles a...Taking half-tube part with curvature as an example,the Impact Hydroforming(IHF)characteristics were studied by combining the actual forming experiment and numerical simulation.The IHF experiment showed that wrinkles appeared at the bottom of the part during single-step forming,but no wrinkles were observed during double-step forming.The thinning rate and deviation of the wall thickness of the part in each area were less than 20%and 2.7 mm,correspondingly,and the drawing depth of the part reached 45.8 mm.The effect of double-step forming was better than that of single-step forming,which was related to the IHF forming law.Besides,the characteristics of the IHF process were studied by numerical simulation.The results indicated that when double-step forming was utilized,there was almost no velocity field in the opposite direction of deformation after the bottom of the part contacted the die,and the existence of stress state at the bottom would restrain and eliminate the wrinkles.The inertia effect evolved with the driving pressure.Specially,the inertia effect can improve the flow of metal and reduce the deviation of the wall thickness of the part under double-step forming.展开更多
Objectives This study aimed to evaluate the effectiveness of the stepped self-care program on the self-care,self-efficacy,and quality of life of stroke survivors.Methods This quasi-experimental study allocated 110 str...Objectives This study aimed to evaluate the effectiveness of the stepped self-care program on the self-care,self-efficacy,and quality of life of stroke survivors.Methods This quasi-experimental study allocated 110 stroke survivors from two neurology wards into an intervention group(n=55)who received the stepped self-care program and a control group(n=55)who received usual care from June to December 2023.The Self-Care of Stroke Inventory,Stroke Self-Efficacy Questionnaire,and the short version of the Stroke Specific Quality of Life Scale were administered at baseline(T0),immediately post-intervention(T_(1)),and at 1-month(T_(2))and 3-month(T_(3))follow-ups.Data were analyzed using repeated measures analyses of variance,and generalized estimating equations.Results A total of 48 participants in the intervention group and 50 participants in the control group completed the study.No statistically significant differences were observed at T0 in any of the measured indicators(all P>0.05).The study showed significant group,time,and group×time interaction effects across the assessed outcomes(all P<0.05).Follow-up between-group comparisons at T_(1),T_(2),and T_(3) indicated that the intervention group had significantly higher scores in self-care maintenance,self-care monitoring,self-care management,self-efficacy,and quality of life than the control group(all P<0.001).Conclusions The stepped self-care program significantly improved self-care behaviors,self-efficacy,and quality of life among stroke survivors.These findings support the broader implementation of this approach in post-discharge home self-care.展开更多
The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and redu...The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption.展开更多
In this paper,we studyλ-biharmonic hypersurfaces M_(r)^(5) of 6-dimensional pseudo Riemannian space form N_(p)^(6)(c)with the indexs 0≤p≤6,r=p−1 or p,and constant curvature c.It was proved that if the shape operato...In this paper,we studyλ-biharmonic hypersurfaces M_(r)^(5) of 6-dimensional pseudo Riemannian space form N_(p)^(6)(c)with the indexs 0≤p≤6,r=p−1 or p,and constant curvature c.It was proved that if the shape operator of M_(r)^(5) is diagonalizable,then the mean curvature is a constant.As an application,we find some types of biharmonic hypersurfaces of N_(p)^(6)(c)are minimal.展开更多
The field of nanomedicine has been revolutionized by the concept of immunogenic cell death(ICD)-enhanced cancer therapy,which holds immense promise for the efficient treatment of cancer.However,precise delivery of ICD...The field of nanomedicine has been revolutionized by the concept of immunogenic cell death(ICD)-enhanced cancer therapy,which holds immense promise for the efficient treatment of cancer.However,precise delivery of ICD inducer is severely hindered by complex biological barriers.How to design and build intelligent nanoplatform for adaptive and dynamic cancer therapy remains a big challenge.Herein,this article presents the design and preparation of CD44-targeting and ZIF-8 gated gold nanocage(Au@ZH) for programmed delivery of the 1,2-diaminocyclohexane-Pt(Ⅱ)(DACHPt) as ICD inducer.After actively targeting the CD44 on the surface of 4T1 tumor cell,this Pt-Au@ZH can be effectively endocytosed by the 4T1 cell and release the DACHPt in tumor acidic environment,resulting in ICD effect and superior antitumor efficacy both in vitro and in vivo in the presence of mild 808 nm laser irradiation.By integration of internal and external stimuli intelligently,this programmed nanoplatform is poised to become a cornerstone in the pursuit of effective and targeted cancer therapy in the foreseeable future.展开更多
During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive...During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive distance)to a moving target as quickly as possible,resulting in the extended minimum-time intercept problem(EMTIP).Existing research has primarily focused on the zero-distance intercept problem,MTIP,establishing the necessary or sufficient conditions for MTIP optimality,and utilizing analytic algorithms,such as root-finding algorithms,to calculate the optimal solutions.However,these approaches depend heavily on the properties of the analytic algorithm,making them inapplicable when problem settings change,such as in the case of a positive effective range or complicated target motions outside uniform rectilinear motion.In this study,an approach employing a high-accuracy and quality-guaranteed mixed-integer piecewise-linear program(QG-PWL)is proposed for the EMTIP.This program can accommodate different effective interception ranges and complicated target motions(variable velocity or complicated trajectories).The high accuracy and quality guarantees of QG-PWL originate from elegant strategies such as piecewise linearization and other developed operation strategies.The approximate error in the intercept path length is proved to be bounded to h^(2)/(4√2),where h is the piecewise length.展开更多
Editor's Note In his keynote address at the opening ceremony of the Global Leaders'Meeting on Women,held in Beijing on October 13,2025,Chinese President Xi Jinping announced a series of measures China will tak...Editor's Note In his keynote address at the opening ceremony of the Global Leaders'Meeting on Women,held in Beijing on October 13,2025,Chinese President Xi Jinping announced a series of measures China will take,in the next five years,to further support the global cause of women.One of the measures is:China will launch 1,000"small and beautiful"livelihood programs with Chinese assistance that take women and girls as priority beneficiaries.展开更多
In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-f...In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-field air-burst experiments are conducted.The damage modes and characteristics of the target plates are compared and analyzed.Each flat plate section is completely punctured,resulting in a penetration hole.The damage modes induced by the three charge types on the stiffened plate structure are consistent,characterized by shear failure in the central region of the flat plate due to penetration by the penetrator,localized plastic deformation of the flat plate,and local penetration failure resulting from partial perforation of the central stiffener.The penetration lengths caused by ELSC and ELEFP are 45.1%and 46.1% larger than that of LSC,while the half-width of the penetration hole generated by ELEFP is 54.2% and 24.7% smaller than that of ELSC and LSC,respectively.The penetration height caused by ELEFP are 17.5%and 62.1% larger than that of ELSC and LSC,respectively.The stiffener effectively segments the damage area,enhancing the local structural strength and limiting the extent of plastic deformation in the flat plate section.The comparative results show that the ELSC proves to be more effective for efficient large-scale damage,and ELEFP is more suitable for achieving efficient localized damage.展开更多
Programmed cell death (PCD) of the nucellar cells at the micropylar end is involved in pollen chamber morphogenesis in Ginkgo biloba L. A development-course observation of the morphological changes in the nucellar cel...Programmed cell death (PCD) of the nucellar cells at the micropylar end is involved in pollen chamber morphogenesis in Ginkgo biloba L. A development-course observation of the morphological changes in the nucellar cells undergoing PCD to form pollen chamber was performed. During the PCD, the nucellar cells degraded their cellular components through an orderly progression. Through the vactiolation, the cytosol was engulfed by the enlarging vacuole, leaving out various organelles, which remained morphologically integrated. As the vacuolation continued, the vacuole collapsed with the breakage of the tonoplast and the cytosol disappeared completely. Organelles were subsequently destroyed. Ultimately, nucellar cells digested away all of their cytoplasm, leaving with cell walls. They became collapsed as the nucellus developed. Intracellular membranes were strikingly changed, playing a role in leading to cell death. Some of these noticeable changes were the appearance of multivesicular body, multicycle-like membranes, membrane-bounded bodies containing some organelles, tonoplast rupture and numerous vesicles. The dehiscence of the apical epidermis, resulting in the opening, appeared to have followed two different pathways with one involving a specific epidermal cell autolysis and the other by detachment from middle lamella of two neighboring epidermal cells without cell autolysis. The specific epidermal cells had been dead prior to the dehiscence of the apical epidermis, which marked the sites of the dehiscence followed. In view of the changes in the cellular morphology, a process of nucellar cell PCD in the course of the pollen chamber formation was demonstrated.展开更多
The high-temperature performance of iron ore fmes is an important factor in optimizing ore blending in sintering. However, the application of linear regression analysis and the linear combination method in most other ...The high-temperature performance of iron ore fmes is an important factor in optimizing ore blending in sintering. However, the application of linear regression analysis and the linear combination method in most other studies always leads to a large deviation from the desired results. In this study, the fuzzy membership functions of the assimilation ability temperature and the liquid fluidity were proposed based on the fuzzy mathematics theory to construct a model for predicting the high-temperature performance of mixed iron ore. Comparisons of the prediction model and experimental results were presented. The results illustrate that the prediction model is more accurate and effective than previously developed models. In addition, fuzzy constraints for the high-temperature performance of iron ore in this research make the results of ore blending more comparable. A solution for the quantitative calculation as well as the programming of fuzzy constraints is also introduced.展开更多
文摘Let f be a primitive holomorphic cusp form with even integral weight k≥2 for the full modular groupΓ=SL(2,Z)andλ_(sym^(j)f)(n)be the n-th coefficient of Dirichlet series of j-th symmetric L-function L(s,sym^(j)f)attached to f.In this paper,we study the mean value distribution over a specific sparse sequence of positive integers of the following sum∑(a^(2)+b^(2)+c^(2)+d^(2)≤x(a,b,c,d)∈Z^(4))λ_(sym^(j))^(i)f(a^(2)+b^(2)+c^(2)+d^(2))where j≥2 is a given positive integer,i=2,3,4 andαis sufficiently large.We utilize Python programming to design algorithms for higher power conditions,combining Perron's formula,latest results of representations of natural integers as sums of squares,as well as analytic properties and subconvexity and convexity bounds of automorphic L-functions,to ensure the accuracy and verifiability of asymptotic formulas.The conclusion we obtained improves previous results and extends them to a more general settings.
文摘With the rapid development of modern science and technology,the era of artificial intelligence has quietly come.Against the background of the new era,students’learning needs,learning resource acquisition methods,teachers’teaching concepts,teaching tools,and so on have changed significantly.How to carry out teaching reform based on this change has become one of the important issues facing educators,and the same is true for the teaching of computer programming courses.This paper focuses on the teaching reform of AI-enabled computer programming courses,analyzes its basic problems,and puts forward corresponding reform countermeasures to provide a useful reference for front-line teachers.
文摘As one of the core courses for computer-related majors,the Python programming course has become increasingly important in the era of artificial intelligence.It aims to help students develop good computer thinking and improve their abilities in programming and data analysis.The application of artificial intelligence technology in the teaching of Python programming courses is of great significance for optimizing the allocation of teaching resources,enriching students’learning experience,and significantly improving teaching quality.Based on this,this paper first briefly expounds on the importance of applying artificial intelligence technology in the teaching of Python programming courses.On this basis,it focuses on exploring effective strategies for the teaching reform of Python programming courses based on artificial intelligence technology,hoping to provide new ideas for the teaching of Python programming courses and contribute to cultivating more Python programming talents with artificial intelligence literacy.
基金funded by Xinjiang Natural Science Foundation of China(2023D01C52)University Key Project(2023YSZD004).
文摘With the continuous advancement of the New Engineering Education initiative,universities are raising the standards for cultivating engineering talents.C Programming Language,as a core course for computer science and related majors,plays a fundamental role in developing logical thinking,programming skills,and engineering practice.However,problems such as outdated content,weak practical connections,and single assessment methods still exist in current teaching,which affects both learning outcomes and students’skill development.Based on the outcome-based education(OBE)approach and supported by AI-assisted teaching tools,this paper proposes a reform plan focusing on teaching content,instructional methods,and evaluation systems.The goal is to enhance students’overall abilities and practical innovation skills,and to align the course more closely with modern industry needs.
基金2023 Southwest Medical University Higher Education Teaching Reform and Research Project(Project No.:JG2023jdyb032)2023 Chengdu Medical College School-level Undergraduate Educational Reform Project(Project No.:JG2023057)-Context of“New Medical Science”。
文摘Objective:To investigate the application effect of the SECI theoretical model-based training program in enhancing clinical nursing teachers‘information-based teaching capabilities.Methods:A self-control study design was adopted,with 124 clinical nursing teachers from a tertiary hospital participating in the SECI training program from January 2024 to June 2025.The program was implemented through four stages:“Establishing Teacher Community(Socialization)”,“Case Teaching(Extravagant)”,“Integration of Discipline and Research(Fusion)”,and“Routine Application of Teaching(Implicit)”.Self-designed questionnaires were used to assess teachers’information-based teaching capabilities before and after training,covering four dimensions:awareness and attitude towards information-based teaching,foundational skills,teaching practice,and professional practice.Data analysis was performed using SPSS 26.0.Results:Post-training,the total score of clinical nursing teachers’information-based teaching capabilities increased from(53.47±15.56)to(78.92±12.34),showing statistically significant differences(t=15.732,P<0.001).Scores in all dimensions also showed significant improvements(P<0.05).Multivariate linear regression analysis revealed that educational background(β=0.198,P=0.026)and professional title(β=0.184,P=0.040)were primary influencing factors for pre-training information-based teaching capabilities,while their impact weakened post-training.Conclusion:The training program based on SECI theory effectively enhances clinical nursing educators’digital teaching capabilities.Its structured,spiral-up knowledge transformation process helps bridge competency gaps among teachers from diverse backgrounds,facilitates the mutual conversion and deep integration of tacit and explicit knowledge,and provides a practical new model for developing digital teaching competencies in clinical nursing education.
基金supported by the Aeronautical Science Foundation of China(20220001057001)an Open Project of the National Key Laboratory of Air-based Information Perception and Fusion(202437)
文摘In this paper,a distributed adaptive dynamic programming(ADP)framework based on value iteration is proposed for multi-player differential games.In the game setting,players have no access to the information of others'system parameters or control laws.Each player adopts an on-policy value iteration algorithm as the basic learning framework.To deal with the incomplete information structure,players collect a period of system trajectory data to compensate for the lack of information.The policy updating step is implemented by a nonlinear optimization problem aiming to search for the proximal admissible policy.Theoretical analysis shows that by adopting proximal policy searching rules,the approximated policies can converge to a neighborhood of equilibrium policies.The efficacy of our method is illustrated by three examples,which also demonstrate that the proposed method can accelerate the learning process compared with the centralized learning framework.
文摘The multi-satellite electromagnetic formation flight system is nonlinear and strongly coupled,which makes modeling and optimization challenging.To simplify electromagnetic force evaluation and dynamics modeling,we introduce a reference frame consistent with each satellite body frame,in which the electromagnetic dipoles and electromagnetic forces are represented as two-dimensional vectors.Then,the maneuver time is divided into time intervals,and different satellite sets are activated in each interval,converting the multi-satellite formation reconfiguration problem into an optimal trajectory problem of each two-satellite subsystem.To this end,a token-based dynamic programming method with a switching penalty of active satellite sets is proposed to determine the sequence of satellite sets participating in each time interval,thereby enabling all satellites to reach their desired states.For the two-satellite subsystem with the objectives of minimizing maneuver time and energy consumption,the Gauss pseudo-spectral method is employed to generate the optimal reconfiguration trajectory.Numerical simulations verify the effectiveness of the proposed optimization method.
基金financially supported by Ministerio de Ciencia e Innovación projects SAF2017-82736-C2-1-R to MTMFin Universidad Autónoma de Madrid and by Fundación Universidad Francisco de Vitoria to JS+2 种基金a predoctoral scholarship from Fundación Universidad Francisco de Vitoriafinancial support from a 6-month contract from Universidad Autónoma de Madrida 3-month contract from the School of Medicine of Universidad Francisco de Vitoria。
文摘Every year, around the world, between 250,000 and 500,000 people suffer a spinal cord injury(SCI). SCI is a devastating medical condition that arises from trauma or disease-induced damage to the spinal cord, disrupting the neural connections that allow communication between the brain and the rest of the body, which results in varying degrees of motor and sensory impairment. Disconnection in the spinal tracts is an irreversible condition owing to the poor capacity for spontaneous axonal regeneration in the affected neurons.
基金financially supported by the National Key R&D Program of China(No.2024YFE0108800/T24KITG014)the National Natural Science Foundation of China(No:52475411)the International Partnership Program of Chinese Academy of Sciences(No.172GJHZ2022096FN)。
文摘Taking half-tube part with curvature as an example,the Impact Hydroforming(IHF)characteristics were studied by combining the actual forming experiment and numerical simulation.The IHF experiment showed that wrinkles appeared at the bottom of the part during single-step forming,but no wrinkles were observed during double-step forming.The thinning rate and deviation of the wall thickness of the part in each area were less than 20%and 2.7 mm,correspondingly,and the drawing depth of the part reached 45.8 mm.The effect of double-step forming was better than that of single-step forming,which was related to the IHF forming law.Besides,the characteristics of the IHF process were studied by numerical simulation.The results indicated that when double-step forming was utilized,there was almost no velocity field in the opposite direction of deformation after the bottom of the part contacted the die,and the existence of stress state at the bottom would restrain and eliminate the wrinkles.The inertia effect evolved with the driving pressure.Specially,the inertia effect can improve the flow of metal and reduce the deviation of the wall thickness of the part under double-step forming.
基金The National Natural Science Foundation of China[72174184]provided policy and financialsupport for this research.
文摘Objectives This study aimed to evaluate the effectiveness of the stepped self-care program on the self-care,self-efficacy,and quality of life of stroke survivors.Methods This quasi-experimental study allocated 110 stroke survivors from two neurology wards into an intervention group(n=55)who received the stepped self-care program and a control group(n=55)who received usual care from June to December 2023.The Self-Care of Stroke Inventory,Stroke Self-Efficacy Questionnaire,and the short version of the Stroke Specific Quality of Life Scale were administered at baseline(T0),immediately post-intervention(T_(1)),and at 1-month(T_(2))and 3-month(T_(3))follow-ups.Data were analyzed using repeated measures analyses of variance,and generalized estimating equations.Results A total of 48 participants in the intervention group and 50 participants in the control group completed the study.No statistically significant differences were observed at T0 in any of the measured indicators(all P>0.05).The study showed significant group,time,and group×time interaction effects across the assessed outcomes(all P<0.05).Follow-up between-group comparisons at T_(1),T_(2),and T_(3) indicated that the intervention group had significantly higher scores in self-care maintenance,self-care monitoring,self-care management,self-efficacy,and quality of life than the control group(all P<0.001).Conclusions The stepped self-care program significantly improved self-care behaviors,self-efficacy,and quality of life among stroke survivors.These findings support the broader implementation of this approach in post-discharge home self-care.
基金the supports of the National Natural Science Foundation of China(Grant No.52375378)。
文摘The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption.
基金Supported by National Natural Science Foundation of China(12161078)Foundation for Innovative Fundamental Research Group Project of Gansu Province(24JRRA778)Project of Northwest Normal University(20240010)。
文摘In this paper,we studyλ-biharmonic hypersurfaces M_(r)^(5) of 6-dimensional pseudo Riemannian space form N_(p)^(6)(c)with the indexs 0≤p≤6,r=p−1 or p,and constant curvature c.It was proved that if the shape operator of M_(r)^(5) is diagonalizable,then the mean curvature is a constant.As an application,we find some types of biharmonic hypersurfaces of N_(p)^(6)(c)are minimal.
基金financially supported by the Natural Science Foundation of Jiangsu Province (No.BK20200709)the Natural Science Foundation of China (Nos.62288102,32201127 and 82270113)+2 种基金the Natural Science Foundation of Guangdong Province (No.2023A1515011386)the Natural Science Foundation of the Jiangsu Higher Education Institutes (No.20KJB430031)the startup fund from Nanjing Tech University,and Disciplinary Fund of School of Pharmaceutical Sciences (2024)。
文摘The field of nanomedicine has been revolutionized by the concept of immunogenic cell death(ICD)-enhanced cancer therapy,which holds immense promise for the efficient treatment of cancer.However,precise delivery of ICD inducer is severely hindered by complex biological barriers.How to design and build intelligent nanoplatform for adaptive and dynamic cancer therapy remains a big challenge.Herein,this article presents the design and preparation of CD44-targeting and ZIF-8 gated gold nanocage(Au@ZH) for programmed delivery of the 1,2-diaminocyclohexane-Pt(Ⅱ)(DACHPt) as ICD inducer.After actively targeting the CD44 on the surface of 4T1 tumor cell,this Pt-Au@ZH can be effectively endocytosed by the 4T1 cell and release the DACHPt in tumor acidic environment,resulting in ICD effect and superior antitumor efficacy both in vitro and in vivo in the presence of mild 808 nm laser irradiation.By integration of internal and external stimuli intelligently,this programmed nanoplatform is poised to become a cornerstone in the pursuit of effective and targeted cancer therapy in the foreseeable future.
基金supported by the National Natural Sci‐ence Foundation of China(Grant No.62306325)。
文摘During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive distance)to a moving target as quickly as possible,resulting in the extended minimum-time intercept problem(EMTIP).Existing research has primarily focused on the zero-distance intercept problem,MTIP,establishing the necessary or sufficient conditions for MTIP optimality,and utilizing analytic algorithms,such as root-finding algorithms,to calculate the optimal solutions.However,these approaches depend heavily on the properties of the analytic algorithm,making them inapplicable when problem settings change,such as in the case of a positive effective range or complicated target motions outside uniform rectilinear motion.In this study,an approach employing a high-accuracy and quality-guaranteed mixed-integer piecewise-linear program(QG-PWL)is proposed for the EMTIP.This program can accommodate different effective interception ranges and complicated target motions(variable velocity or complicated trajectories).The high accuracy and quality guarantees of QG-PWL originate from elegant strategies such as piecewise linearization and other developed operation strategies.The approximate error in the intercept path length is proved to be bounded to h^(2)/(4√2),where h is the piecewise length.
文摘Editor's Note In his keynote address at the opening ceremony of the Global Leaders'Meeting on Women,held in Beijing on October 13,2025,Chinese President Xi Jinping announced a series of measures China will take,in the next five years,to further support the global cause of women.One of the measures is:China will launch 1,000"small and beautiful"livelihood programs with Chinese assistance that take women and girls as priority beneficiaries.
基金supported by the National Natural Science Foundation of China(Grant Nos.52271307,52061135107,52192692,11802025)the Liao Ning Excellent Youth Fund Program(Grant No.2023JH3/10200012)+1 种基金the Liao Ning Revitalization Tal-ents Program(Grant No.XLYC1908027)the Fundamental Research Funds for the Central Universities(Grant Nos.DUT20RC(3)025,DUT20TD108,DUT20LAB308)。
文摘In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-field air-burst experiments are conducted.The damage modes and characteristics of the target plates are compared and analyzed.Each flat plate section is completely punctured,resulting in a penetration hole.The damage modes induced by the three charge types on the stiffened plate structure are consistent,characterized by shear failure in the central region of the flat plate due to penetration by the penetrator,localized plastic deformation of the flat plate,and local penetration failure resulting from partial perforation of the central stiffener.The penetration lengths caused by ELSC and ELEFP are 45.1%and 46.1% larger than that of LSC,while the half-width of the penetration hole generated by ELEFP is 54.2% and 24.7% smaller than that of ELSC and LSC,respectively.The penetration height caused by ELEFP are 17.5%and 62.1% larger than that of ELSC and LSC,respectively.The stiffener effectively segments the damage area,enhancing the local structural strength and limiting the extent of plastic deformation in the flat plate section.The comparative results show that the ELSC proves to be more effective for efficient large-scale damage,and ELEFP is more suitable for achieving efficient localized damage.
文摘Programmed cell death (PCD) of the nucellar cells at the micropylar end is involved in pollen chamber morphogenesis in Ginkgo biloba L. A development-course observation of the morphological changes in the nucellar cells undergoing PCD to form pollen chamber was performed. During the PCD, the nucellar cells degraded their cellular components through an orderly progression. Through the vactiolation, the cytosol was engulfed by the enlarging vacuole, leaving out various organelles, which remained morphologically integrated. As the vacuolation continued, the vacuole collapsed with the breakage of the tonoplast and the cytosol disappeared completely. Organelles were subsequently destroyed. Ultimately, nucellar cells digested away all of their cytoplasm, leaving with cell walls. They became collapsed as the nucellus developed. Intracellular membranes were strikingly changed, playing a role in leading to cell death. Some of these noticeable changes were the appearance of multivesicular body, multicycle-like membranes, membrane-bounded bodies containing some organelles, tonoplast rupture and numerous vesicles. The dehiscence of the apical epidermis, resulting in the opening, appeared to have followed two different pathways with one involving a specific epidermal cell autolysis and the other by detachment from middle lamella of two neighboring epidermal cells without cell autolysis. The specific epidermal cells had been dead prior to the dehiscence of the apical epidermis, which marked the sites of the dehiscence followed. In view of the changes in the cellular morphology, a process of nucellar cell PCD in the course of the pollen chamber formation was demonstrated.
基金financially supported by the National Natural Science Foundation of China (No. 51204013)the National Key Technology R&D Program in the 12th Five Year Plan of China (No. 2011BAC01B02)
文摘The high-temperature performance of iron ore fmes is an important factor in optimizing ore blending in sintering. However, the application of linear regression analysis and the linear combination method in most other studies always leads to a large deviation from the desired results. In this study, the fuzzy membership functions of the assimilation ability temperature and the liquid fluidity were proposed based on the fuzzy mathematics theory to construct a model for predicting the high-temperature performance of mixed iron ore. Comparisons of the prediction model and experimental results were presented. The results illustrate that the prediction model is more accurate and effective than previously developed models. In addition, fuzzy constraints for the high-temperature performance of iron ore in this research make the results of ore blending more comparable. A solution for the quantitative calculation as well as the programming of fuzzy constraints is also introduced.
