Aimed at the stabilization of the nonholonomic chained system under fixed sample control, two control laws were proposed. The discrete model of the nonholonomic chained system under zero-hold was obtained through the ...Aimed at the stabilization of the nonholonomic chained system under fixed sample control, two control laws were proposed. The discrete model of the nonholonomic chained system under zero-hold was obtained through the integrate method to the continuous model. And the discrete model was transformed to the form with two linear subsystems through coordinate transformation. Two feedback control laws, time-invariant control law and time-varying control law, were proposed; and the local stabilization and global stabilization were realized respectively. The simulation results show the effectiveness of the proposed control laws. The discrete nonholonomic chained system can converge to zero from any initial state exponentially, and the convergence rate can be changed through changing the parameters of the control laws.展开更多
A novel double chained amphiphile, N-(α-4-hexylphenoxy)-lauroyltaurate (abbreviated as 10 + 6B-T), has been synthesized. The structures of main intermediate products and the title product were characterized by 1H NMR...A novel double chained amphiphile, N-(α-4-hexylphenoxy)-lauroyltaurate (abbreviated as 10 + 6B-T), has been synthesized. The structures of main intermediate products and the title product were characterized by 1H NMR. The new amphiphile shows high surface activity. The critical micelle concentration (cmc), which is 1.1 × 10?5 mol/L, is much lower than that of conventional double chained surfactants, such as sodium bis(2-ethylhexyl)sulfosuccinate (AOT).展开更多
The M_(S)6.8 Luding earthquake in 2022 is located on the NNW-trending Moxi segment of the Xianshuihe fault with left-lateral strike-slip behavior.This area is where the Xianshuihe,Anninghe,Daliangshan and Longmenshan ...The M_(S)6.8 Luding earthquake in 2022 is located on the NNW-trending Moxi segment of the Xianshuihe fault with left-lateral strike-slip behavior.This area is where the Xianshuihe,Anninghe,Daliangshan and Longmenshan faults intersect.China Earthquake Administration has identified that intersection area,among the Moxi segment of the Xianshuihe fault,the Anninghe fault,the Daliangshan fault and the southern part of the Longmenshan fault,as a high-magnitude earthquake hazard area.According to existing data on the Luding earthquake,including the focal parameters,the spatial distribution of re-located aftershocks,dominated azimuth of the earthquake intensities and earthquake-induced ground fissures,we built a 3D earthquake fault model.We found that two discontinuous NNW-trending vertical strike-slip faults with left stepping were the seismogenic faults of the Luding earthquake.Its coseismic left-lateral dislocation triggered transtensional slips and aftershocks on the NW-trending secondary faults at its northernmost tensile area.Meanwhile,local crustal coseismic shortening on the side of Mt.Gongga triggered the aftershocks on the NE-and NW-trending secondary conjugated strike-slip faults,which were confirmed by GNSS observations and In SAR deformation field around the epicenter.This earthquake rupturing pattern also controlled the spatial distribution of the earthquake intensity IX area and earthquake chain hazards.The Coulomb stress calculation shows that the Luding earthquake increases the risk of high-magnitude earthquake occurrence on the southernmost part of the Xianshuihe fault and the Anninghe fault.Finally,we suggested doing good monitoring of the Anninghe fault and the southernmost part of the Xianshuihe fault and avoiding active faults with seismogenic capacity and areas prone to earthquake-chained hazards during the site selection and planning of reconstruction.展开更多
Threshold Proxy Signature (TPS) scheme facilitates a manager to delegate his signing capability to a group of n2 sub-ordinates without revealing his own private key, such that a subgroup of at least t2 ≤ n2 subordina...Threshold Proxy Signature (TPS) scheme facilitates a manager to delegate his signing capability to a group of n2 sub-ordinates without revealing his own private key, such that a subgroup of at least t2 ≤ n2 subordinates is required to generate a proxy signature. In reality, the situation can be more complicated. First of all, the subgroup may further delegate their proxy signing capabilities to another group of n3 subordinates such that at least another subgroup of at least t3 ≤ n3 subordinates are of the proxy signing capabilities (in the form of a chain). t2 can be unequal to t3 depending on the concrete requirement. This is a group-to-group delegation problem. In addition, a supervising agent (SA) may be introduced in the above chain to supervise the subordinates, such that proxy signing can only be successfully executed with SA’s agreement. This is a delegation with supervision problem in the threshold delegation chain described above. These two extensions of delegation problems are not solved yet. This paper designs two provably secure cryptographic schemes Chained Threshold Proxy Signature (CTPS) scheme and Chained Threshold Proxy Signature with Supervision (CTPSwS) scheme to solve these two delegation problems.展开更多
Background:In the Chinese context,the impact of short video applications on the psychological well-being of older adults is contested.While often examined through a pathological lens of addiction,this perspective may ...Background:In the Chinese context,the impact of short video applications on the psychological well-being of older adults is contested.While often examined through a pathological lens of addiction,this perspective may overlook paradoxical,context-dependent positive outcomes.Therefore,the main objective of this study is to challenge the traditional Compensatory Internet Use Theory by proposing and testing a chained mediation model that explores a paradoxical pathway from social support to life satisfaction via problematic social media use.Methods:Data were collected between July and August 2025 via the Credamo online survey platform,yielding 384 valid responses from Chinese older adults aged 60 and above.Key constructs were assessed using the Social Support Rating Scale(SSRS),Bergen Social Media Addiction Scale(BSMAS),Simplified UCLA Loneliness Scale,and Satisfaction with Life Scale(SWLS).A chained mediation model was tested using stepwise regression and non-parametric bootstrapping(5000 resamples),controlling for age,gender,household income,and health status.Results:The analysis revealed a paradoxical pathway,which was clarified by a key statistical suppression effect.Social support significantly and positively predicted problematic usage(β=0.157,p=0.002).After controlling for the suppressor effect of social support,problematic usage in turn negatively predicted social connectedness(β=−0.177,p<0.001).Finally,reduced social connectedness—reflecting a state of solitude—positively predicted life satisfaction(β=−0.227,p<0.001).Conclusion:The findings suggest that for older adults with sufficient offline social support,these resources may serve a“social empowerment”function.This empowerment allows behaviors measured as“problematic usage”to be theoretically reframed as a form of“deep immersive entertainment”.This immersion appears to occur alongside a state of“high-quality solitude”,which ultimately is associated with higher life satisfaction.This study provides a novel,non-pathological theoretical perspective on the consequences of high engagement with emerging social media,offering empirical grounds for non-abstinence-based intervention strategies.展开更多
This paper reviews some main results and progress concerning with nonholonomic system control,especially focusing on the networked chained system coordination.The controllability of nonholonomic system,the control met...This paper reviews some main results and progress concerning with nonholonomic system control,especially focusing on the networked chained system coordination.The controllability of nonholonomic system,the control method of nonholonomic system,the chained form transformation,the basic graph theory for multi-agent systems are recalled,respectively.Some important definitions,lemmas,theorems and dynamics are elaborated.Both the consensus and formation control problems for networked nonholonomic chained systems are summarised.Finally,some open questions are proposed.展开更多
The visual serving stabilization for a kind of nonholonomic mobile robots with uncalibrated camera parameters is investigated based on the visual feedback and the state and input transforma- tions. The authors obtain ...The visual serving stabilization for a kind of nonholonomic mobile robots with uncalibrated camera parameters is investigated based on the visual feedback and the state and input transforma- tions. The authors obtain a new uncertain model of the nonholonomic kinematic system in the image plane, which is a chained form with uncalibrated visual parameters, from the camera robotic system. A new time varying feedback controller is proposed for the exponential stabilization of the nonholonomic chained system with unknown parameters by using state-scaling and switching technique. The exponential stability of the closed loop system is rigorously proved. Simulation results demonstrate the effectiveness of the proposed methods.展开更多
Dynamic fund protection provides a guarantee that the account value of the investor never drops below a barrier over the investment period.In order to reduce the downside risk taken by vendors,Han,et al.(2016)proposed...Dynamic fund protection provides a guarantee that the account value of the investor never drops below a barrier over the investment period.In order to reduce the downside risk taken by vendors,Han,et al.(2016)proposed a chained dynamic fund protection(CDFP),whose protection is activated only if the value of basic fund reaches a predefined upper protection line.Motivated by them,we consider a new CDFP plan under a stochastic interest rate environment.The explicit pricing formula for a CDFP is obtained when the protection lines are proportional to a zero-coupon bond.Furthermore,the authors present some numerical results for the value of CDFP at time 0 to show how the model parameters impact the value of CDFP.展开更多
Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’...Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease.展开更多
Arbitrated quantum signature(AQS) is an important branch in quantum cryptography to authenticate quantum information, and cryptanalysis on AQS protocols helps to evaluate and improve security of AQS. Recently, it is d...Arbitrated quantum signature(AQS) is an important branch in quantum cryptography to authenticate quantum information, and cryptanalysis on AQS protocols helps to evaluate and improve security of AQS. Recently, it is discovered that an AQS protocol based on chained controlled-NOT(CNOT) algorithm is vulnerable to a novel attack because a transformation from binary keys into permutations and the chained CNOT algorithm have special properties, which enables a malicious receiver to forge signatures with probability 1/2. Moreover, a malicious signer can also deny his signatures with probability 1/4. Then, two possible improved methods are presented to resist these attacks: one is padding constants to reduce probability of the successful attacks, and the other is a circular chained CNOT algorithm to make the attack strategy invalid. And the security analysis shows that both the two improve methods could well resist these attacks.展开更多
A system for a type of nonholonomic wheeled mobile robots equipped with an uncalibrated camera fixed to the ceiling is investigated.Based on the visual feedback and the state-input transformation,models of uncertain c...A system for a type of nonholonomic wheeled mobile robots equipped with an uncalibrated camera fixed to the ceiling is investigated.Based on the visual feedback and the state-input transformation,models of uncertain chained form systems are presented for the robot-camera systems.Then,new smooth time-varying feedback controllers are proposed to exponentially stabilize the uncertain chained system by using state-scaling and control theories for two cases.The exponential stabilities of the closed-loop uncertain systems are rigorously proved.Simulation results demonstrate the effectiveness of the proposed strategies.展开更多
The China-ASEAN Free Trade Area(CAFTA)3.0Upgrade Protocol added a section on“Supply Chain Connectivity,”which emphasizes that all parties recognize the lessons learned from the COVID-19 pandemic and cooperate to enh...The China-ASEAN Free Trade Area(CAFTA)3.0Upgrade Protocol added a section on“Supply Chain Connectivity,”which emphasizes that all parties recognize the lessons learned from the COVID-19 pandemic and cooperate to enhance the resilience of the regional supply chain.This is an inevitable trend amid the current accelerated restructuring of the global supply chain,the complex and severe international economic and trade situation,and the impact on the regional industrial chain.It also represents a fundamental shift and consensus on the logic of supply chain cooperation between China and ASEAN countries—a transformation from“Efficiency First”to“Resilience First.”展开更多
The world economy is now in a period of indepth adjustment.The intensification of geopolitical conflicts,a rise of trade protectionism,and reconfiguration of global supply chains have prompted all countries to re-exam...The world economy is now in a period of indepth adjustment.The intensification of geopolitical conflicts,a rise of trade protectionism,and reconfiguration of global supply chains have prompted all countries to re-examine their openness to trade amid rising uncertainties.Against this backdrop,China’s continuing commitment to promoting higherlevel opening up and building the Hainan Free Trade Port(Hainan FTP)has distinct contemporary significance and strategic value.展开更多
The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited im...The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited imaginary frequencies in their phonon spectra at 0 GPa.Here,we conducted a systematic investigation of P-N compounds using first-principles calculations,uncovering a series of structurally similar stable phases,C2/m-PN_(x)(x=6,8,10,12,and 14),in which N forms zigzag N chains similar to those in Ch-N.In P-N compounds,the longest zigzag N-chain,which can theoretically remain stable under ambient pressure,is the N-chain composed of 14 N atoms in C2/m-PN14.If the N-chain continues to grow,imaginary interchain vibrational frequencies arise in the system.Notably,N chains with an even number of atoms were more likely to be energetically favorable.The five C2/m-PN_(x) phases and one metastable phase(R-PN_(6))exhibited remarkable stability and excellent detonability at ambient pressure,indicating that they are promising candidates for high-energy-density materials.In addition,R-PN_(6) was the first structure to stabilize the N_(6) ring through covalent bonding,with the covalent network contributing to its high hardness(47.59 GPa).展开更多
Against a backdrop of rising global trade protectionism and accelerated restructuring of international industrial and supply chains,regional institutional cooperation is becoming a key force in stabilizing cross-borde...Against a backdrop of rising global trade protectionism and accelerated restructuring of international industrial and supply chains,regional institutional cooperation is becoming a key force in stabilizing cross-border trade and investment.The ASEAN region enjoys strong economic growth momentum with a distinct demographic advantage while China boasts a complete industrial system and manufacturing capacity.展开更多
The exponential stabilization problem of a robot-camera system with unknown camera parameters is investigated. Based on the visual feedback and the state-input transformation, an uncertain chained form model is presen...The exponential stabilization problem of a robot-camera system with unknown camera parameters is investigated. Based on the visual feedback and the state-input transformation, an uncertain chained form model is presented for a type of nonholonomic mobile robots. Then, a new time-varying feedback controller is proposed to stabilize the uncertain system exponentially with the help of the stabilization theorems, state-scaling and switching techniques. The exponential stability of the closed-loop system is rigorously proved. Simulation results are given to demonstrate the effectiveness of the proposed strategies.展开更多
Despite demonstrating significant anti-tumor potential as an artemisinin derivative,artesunate faces delivery efficiency challenges due to low water solubility and insufficient targeting specificity.To improve the del...Despite demonstrating significant anti-tumor potential as an artemisinin derivative,artesunate faces delivery efficiency challenges due to low water solubility and insufficient targeting specificity.To improve the delivery efficiency,we engineered three artesunate(ART) derivatives,AC_(15)-L(linear),AC_(15)-B(branched),and AC_(15)-C(cyclic) with distinct aliphatic chain architectures.Unexpectedly,we observed that AC_(15)-C exhibited superior cytotoxicity against 4T1 breast cancer cells,and had the highest binding affinity for Lon protease 1(LONP1)(-72.6 kcal/mol).Subsequently,disulfide bond-containing lipid-PEG(DSPESS-PEG2K) modified chain architecture-engineered ART derivatives nanoassemblies(NAs) were developed to mitigate solubility-related limitations while enhancing targeting precision.Molecular docking and experimental validation demonstrated that ART derivatives inhibited LONP1 through hydrophobic interactions while preserved Fe^(2+)-mediated Fenton-like reaction activity.In vitro and in vivo evaluations demonstrated that AC_(15)-C NAs outperformed free ART and other NAs,suppressing 4T1 tumor growth via dual action:LONP1-directed mitochondrial proteostasis collapse and reactive oxygen species(ROS) amplification through Fe^(2+)-ART interactions.This study elucidated a novel anti-tumor mechanism of ART through the rational design of derivatives with spatially configured aliphatic chains,and developed reductionresponsive NAs to provide an advanced delivery strategy.展开更多
Purpose-This study explores how managerial leadership and organizational innovation interact to enhance resilience and risk management in railway supply chains and how these capabilities contribute to sustained compet...Purpose-This study explores how managerial leadership and organizational innovation interact to enhance resilience and risk management in railway supply chains and how these capabilities contribute to sustained competitive advantage.It emphasizes the strategic importance of resilience in railway systems that face operational complexity,regulatory pressures and increasing exposure to systemic risks.Design/methodology/approach-A mixed-methods design was employed,integrating survey data from 186 railway organizations with six case studies involving railway operators,rolling stock manufacturers and supply chain partners across multiple regions.Constructs were measured using validated scales and hypothesized relationships were tested using Structural Equation Modeling(SEM).Case study interviews were analyzed thematically to provide contextual understanding of leadership practices and innovation strategies.Findings-The results confirm that transformational managerial leadership significantly predicts innovation adoption,which in turn strengthens resilience and risk management capabilities.Resilience emerged as a powerful driver of competitive advantage,reinforcing its role as a strategic capability rather than a reactive response to disruptions.Furthermore,innovation was shown to partially mediate the relationship between leadership and resilience,highlighting its function as the operational channel through which vision translates into capability.Originality/value-This study contributes to the literature by integrating the Resource-Based View(RBV)and Dynamic Capabilities(DC)framework into the context of railway supply chains.It is among the first to empirically validate the mediating role of innovation between leadership and resilience,offering both theoretical advancements and actionable strategies for building resilient and competitive railway systems.展开更多
The generation of synthetic trajectories has become essential in various fields for analyzing complex movement patterns.However,the use of real-world trajectory data poses significant privacy risks,such as location re...The generation of synthetic trajectories has become essential in various fields for analyzing complex movement patterns.However,the use of real-world trajectory data poses significant privacy risks,such as location reidentification and correlation attacks.To address these challenges,privacy-preserving trajectory generation methods are critical for applications relying on sensitive location data.This paper introduces DPIL-Traj,an advanced framework designed to generate synthetic trajectories while achieving a superior balance between data utility and privacy preservation.Firstly,the framework incorporates Differential Privacy Clustering,which anonymizes trajectory data by applying differential privacy techniques that add noise,ensuring the protection of sensitive user information.Secondly,Imitation Learning is used to replicate decision-making behaviors observed in real-world trajectories.By learning from expert trajectories,this component generates synthetic data that closely mimics real-world decision-making processes while optimizing the quality of the generated trajectories.Finally,Markov-based Trajectory Generation is employed to capture and maintain the inherent temporal dynamics of movement patterns.Extensive experiments conducted on the GeoLife trajectory dataset show that DPIL-Traj improves utility performance by an average of 19.85%,and in terms of privacy performance by an average of 12.51%,compared to state-of-the-art approaches.Ablation studies further reveal that DP clustering effectively safeguards privacy,imitation learning enhances utility under noise,and the Markov module strengthens temporal coherence.展开更多
China releases first standards system for humanoid robots and embodied intelligence The Annual Meeting of Humanoid and Embodied Intelligence Standardization(HEIS)was held on February 28 in Beijing.The 2026 version of ...China releases first standards system for humanoid robots and embodied intelligence The Annual Meeting of Humanoid and Embodied Intelligence Standardization(HEIS)was held on February 28 in Beijing.The 2026 version of the standards system for humanoid robots and embodied intelligence was released at the meeting,which is the first top-level design of standards for the entire industrial chain and lifecycle of humanoid robots and embodied intelligence in China,marking that the related industries are embarking on a new chapter of standardized development.展开更多
文摘Aimed at the stabilization of the nonholonomic chained system under fixed sample control, two control laws were proposed. The discrete model of the nonholonomic chained system under zero-hold was obtained through the integrate method to the continuous model. And the discrete model was transformed to the form with two linear subsystems through coordinate transformation. Two feedback control laws, time-invariant control law and time-varying control law, were proposed; and the local stabilization and global stabilization were realized respectively. The simulation results show the effectiveness of the proposed control laws. The discrete nonholonomic chained system can converge to zero from any initial state exponentially, and the convergence rate can be changed through changing the parameters of the control laws.
文摘A novel double chained amphiphile, N-(α-4-hexylphenoxy)-lauroyltaurate (abbreviated as 10 + 6B-T), has been synthesized. The structures of main intermediate products and the title product were characterized by 1H NMR. The new amphiphile shows high surface activity. The critical micelle concentration (cmc), which is 1.1 × 10?5 mol/L, is much lower than that of conventional double chained surfactants, such as sodium bis(2-ethylhexyl)sulfosuccinate (AOT).
基金supported by the National Natural Science Foundation of China(41941016)the National Natural Science Foundation of China(U1839204)。
文摘The M_(S)6.8 Luding earthquake in 2022 is located on the NNW-trending Moxi segment of the Xianshuihe fault with left-lateral strike-slip behavior.This area is where the Xianshuihe,Anninghe,Daliangshan and Longmenshan faults intersect.China Earthquake Administration has identified that intersection area,among the Moxi segment of the Xianshuihe fault,the Anninghe fault,the Daliangshan fault and the southern part of the Longmenshan fault,as a high-magnitude earthquake hazard area.According to existing data on the Luding earthquake,including the focal parameters,the spatial distribution of re-located aftershocks,dominated azimuth of the earthquake intensities and earthquake-induced ground fissures,we built a 3D earthquake fault model.We found that two discontinuous NNW-trending vertical strike-slip faults with left stepping were the seismogenic faults of the Luding earthquake.Its coseismic left-lateral dislocation triggered transtensional slips and aftershocks on the NW-trending secondary faults at its northernmost tensile area.Meanwhile,local crustal coseismic shortening on the side of Mt.Gongga triggered the aftershocks on the NE-and NW-trending secondary conjugated strike-slip faults,which were confirmed by GNSS observations and In SAR deformation field around the epicenter.This earthquake rupturing pattern also controlled the spatial distribution of the earthquake intensity IX area and earthquake chain hazards.The Coulomb stress calculation shows that the Luding earthquake increases the risk of high-magnitude earthquake occurrence on the southernmost part of the Xianshuihe fault and the Anninghe fault.Finally,we suggested doing good monitoring of the Anninghe fault and the southernmost part of the Xianshuihe fault and avoiding active faults with seismogenic capacity and areas prone to earthquake-chained hazards during the site selection and planning of reconstruction.
文摘Threshold Proxy Signature (TPS) scheme facilitates a manager to delegate his signing capability to a group of n2 sub-ordinates without revealing his own private key, such that a subgroup of at least t2 ≤ n2 subordinates is required to generate a proxy signature. In reality, the situation can be more complicated. First of all, the subgroup may further delegate their proxy signing capabilities to another group of n3 subordinates such that at least another subgroup of at least t3 ≤ n3 subordinates are of the proxy signing capabilities (in the form of a chain). t2 can be unequal to t3 depending on the concrete requirement. This is a group-to-group delegation problem. In addition, a supervising agent (SA) may be introduced in the above chain to supervise the subordinates, such that proxy signing can only be successfully executed with SA’s agreement. This is a delegation with supervision problem in the threshold delegation chain described above. These two extensions of delegation problems are not solved yet. This paper designs two provably secure cryptographic schemes Chained Threshold Proxy Signature (CTPS) scheme and Chained Threshold Proxy Signature with Supervision (CTPSwS) scheme to solve these two delegation problems.
基金funded by the Guangxi Philosophy and Social Science Research Project,grant number 24XWC002.
文摘Background:In the Chinese context,the impact of short video applications on the psychological well-being of older adults is contested.While often examined through a pathological lens of addiction,this perspective may overlook paradoxical,context-dependent positive outcomes.Therefore,the main objective of this study is to challenge the traditional Compensatory Internet Use Theory by proposing and testing a chained mediation model that explores a paradoxical pathway from social support to life satisfaction via problematic social media use.Methods:Data were collected between July and August 2025 via the Credamo online survey platform,yielding 384 valid responses from Chinese older adults aged 60 and above.Key constructs were assessed using the Social Support Rating Scale(SSRS),Bergen Social Media Addiction Scale(BSMAS),Simplified UCLA Loneliness Scale,and Satisfaction with Life Scale(SWLS).A chained mediation model was tested using stepwise regression and non-parametric bootstrapping(5000 resamples),controlling for age,gender,household income,and health status.Results:The analysis revealed a paradoxical pathway,which was clarified by a key statistical suppression effect.Social support significantly and positively predicted problematic usage(β=0.157,p=0.002).After controlling for the suppressor effect of social support,problematic usage in turn negatively predicted social connectedness(β=−0.177,p<0.001).Finally,reduced social connectedness—reflecting a state of solitude—positively predicted life satisfaction(β=−0.227,p<0.001).Conclusion:The findings suggest that for older adults with sufficient offline social support,these resources may serve a“social empowerment”function.This empowerment allows behaviors measured as“problematic usage”to be theoretically reframed as a form of“deep immersive entertainment”.This immersion appears to occur alongside a state of“high-quality solitude”,which ultimately is associated with higher life satisfaction.This study provides a novel,non-pathological theoretical perspective on the consequences of high engagement with emerging social media,offering empirical grounds for non-abstinence-based intervention strategies.
基金supported in part by the National Natural Science Foundation of China under[grant number 61321002],[grant number 61120106010],[grant number 61175112]the programme for New Century Excellent Talents in University+1 种基金the Social Science Foundation of Fujian Province under[grant number 2014B182]the Beijing Education Committee Cooperation Building Foundation Project.
文摘This paper reviews some main results and progress concerning with nonholonomic system control,especially focusing on the networked chained system coordination.The controllability of nonholonomic system,the control method of nonholonomic system,the chained form transformation,the basic graph theory for multi-agent systems are recalled,respectively.Some important definitions,lemmas,theorems and dynamics are elaborated.Both the consensus and formation control problems for networked nonholonomic chained systems are summarised.Finally,some open questions are proposed.
基金supported by the National Science Foundation under Grant No.60874002Key Project of Shanghai Education Committee under Grant No.09ZZ158+1 种基金Key Discipline of Shanghai under Grant No.S30501Doctoral Fund of Shandong University of Technology under Grant No.411016
文摘The visual serving stabilization for a kind of nonholonomic mobile robots with uncalibrated camera parameters is investigated based on the visual feedback and the state and input transforma- tions. The authors obtain a new uncertain model of the nonholonomic kinematic system in the image plane, which is a chained form with uncalibrated visual parameters, from the camera robotic system. A new time varying feedback controller is proposed for the exponential stabilization of the nonholonomic chained system with unknown parameters by using state-scaling and switching technique. The exponential stability of the closed loop system is rigorously proved. Simulation results demonstrate the effectiveness of the proposed methods.
基金supported by the NSF of Jiangsu Province under Grant No.BK20170064the NNSF of China under Grant No.11771320+2 种基金Qing Lan Project of Jiangsu Provincethe scholarship of Jiangsu Overseas Visiting Scholar Programthe Graduate Innovation Program of USTS(SKCX18-Y06)
文摘Dynamic fund protection provides a guarantee that the account value of the investor never drops below a barrier over the investment period.In order to reduce the downside risk taken by vendors,Han,et al.(2016)proposed a chained dynamic fund protection(CDFP),whose protection is activated only if the value of basic fund reaches a predefined upper protection line.Motivated by them,we consider a new CDFP plan under a stochastic interest rate environment.The explicit pricing formula for a CDFP is obtained when the protection lines are proportional to a zero-coupon bond.Furthermore,the authors present some numerical results for the value of CDFP at time 0 to show how the model parameters impact the value of CDFP.
基金supported by the National Key R&D Program of China,No.2021YFC2501200(to PC).
文摘Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease.
基金supported by the National Natural Science Foundation of China (61502048)the National Science and Technology Major Project (2017YFB0803001)
文摘Arbitrated quantum signature(AQS) is an important branch in quantum cryptography to authenticate quantum information, and cryptanalysis on AQS protocols helps to evaluate and improve security of AQS. Recently, it is discovered that an AQS protocol based on chained controlled-NOT(CNOT) algorithm is vulnerable to a novel attack because a transformation from binary keys into permutations and the chained CNOT algorithm have special properties, which enables a malicious receiver to forge signatures with probability 1/2. Moreover, a malicious signer can also deny his signatures with probability 1/4. Then, two possible improved methods are presented to resist these attacks: one is padding constants to reduce probability of the successful attacks, and the other is a circular chained CNOT algorithm to make the attack strategy invalid. And the security analysis shows that both the two improve methods could well resist these attacks.
基金supported by the National Natural Science Foundation of China under Grant Nos.61374040,61304004 and 61473179the Natural Science Foundation of Shandong Province under Grant Nos.ZR2013FM012 and ZR2014FM007
文摘A system for a type of nonholonomic wheeled mobile robots equipped with an uncalibrated camera fixed to the ceiling is investigated.Based on the visual feedback and the state-input transformation,models of uncertain chained form systems are presented for the robot-camera systems.Then,new smooth time-varying feedback controllers are proposed to exponentially stabilize the uncertain chained system by using state-scaling and control theories for two cases.The exponential stabilities of the closed-loop uncertain systems are rigorously proved.Simulation results demonstrate the effectiveness of the proposed strategies.
文摘The China-ASEAN Free Trade Area(CAFTA)3.0Upgrade Protocol added a section on“Supply Chain Connectivity,”which emphasizes that all parties recognize the lessons learned from the COVID-19 pandemic and cooperate to enhance the resilience of the regional supply chain.This is an inevitable trend amid the current accelerated restructuring of the global supply chain,the complex and severe international economic and trade situation,and the impact on the regional industrial chain.It also represents a fundamental shift and consensus on the logic of supply chain cooperation between China and ASEAN countries—a transformation from“Efficiency First”to“Resilience First.”
文摘The world economy is now in a period of indepth adjustment.The intensification of geopolitical conflicts,a rise of trade protectionism,and reconfiguration of global supply chains have prompted all countries to re-examine their openness to trade amid rising uncertainties.Against this backdrop,China’s continuing commitment to promoting higherlevel opening up and building the Hainan Free Trade Port(Hainan FTP)has distinct contemporary significance and strategic value.
基金supported by the Anhui Provincial Natural Science Foundation (Grant No.2508085J006)CASHIPS Director's Fund (Grant No.YZJJ202207-CX)。
文摘The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited imaginary frequencies in their phonon spectra at 0 GPa.Here,we conducted a systematic investigation of P-N compounds using first-principles calculations,uncovering a series of structurally similar stable phases,C2/m-PN_(x)(x=6,8,10,12,and 14),in which N forms zigzag N chains similar to those in Ch-N.In P-N compounds,the longest zigzag N-chain,which can theoretically remain stable under ambient pressure,is the N-chain composed of 14 N atoms in C2/m-PN14.If the N-chain continues to grow,imaginary interchain vibrational frequencies arise in the system.Notably,N chains with an even number of atoms were more likely to be energetically favorable.The five C2/m-PN_(x) phases and one metastable phase(R-PN_(6))exhibited remarkable stability and excellent detonability at ambient pressure,indicating that they are promising candidates for high-energy-density materials.In addition,R-PN_(6) was the first structure to stabilize the N_(6) ring through covalent bonding,with the covalent network contributing to its high hardness(47.59 GPa).
文摘Against a backdrop of rising global trade protectionism and accelerated restructuring of international industrial and supply chains,regional institutional cooperation is becoming a key force in stabilizing cross-border trade and investment.The ASEAN region enjoys strong economic growth momentum with a distinct demographic advantage while China boasts a complete industrial system and manufacturing capacity.
基金Supported by the the National Natural Science Foundation of China(Nos.61374040,61304004 and 61473179)Natural Science Foundation of Shandong Province(Nos.ZR2013FM012,ZR2014FM007)
文摘The exponential stabilization problem of a robot-camera system with unknown camera parameters is investigated. Based on the visual feedback and the state-input transformation, an uncertain chained form model is presented for a type of nonholonomic mobile robots. Then, a new time-varying feedback controller is proposed to stabilize the uncertain system exponentially with the help of the stabilization theorems, state-scaling and switching techniques. The exponential stability of the closed-loop system is rigorously proved. Simulation results are given to demonstrate the effectiveness of the proposed strategies.
基金financially supported by the Liaoning Revitalization Talents Program (No.XLYC2403107)the Excellent Youth Science Foundation of Liaoning Province (No.2024JH3/10200046)the Basic Scientific Research Project of Liaoning Provincial Department of Education (No.LJ212410163015)。
文摘Despite demonstrating significant anti-tumor potential as an artemisinin derivative,artesunate faces delivery efficiency challenges due to low water solubility and insufficient targeting specificity.To improve the delivery efficiency,we engineered three artesunate(ART) derivatives,AC_(15)-L(linear),AC_(15)-B(branched),and AC_(15)-C(cyclic) with distinct aliphatic chain architectures.Unexpectedly,we observed that AC_(15)-C exhibited superior cytotoxicity against 4T1 breast cancer cells,and had the highest binding affinity for Lon protease 1(LONP1)(-72.6 kcal/mol).Subsequently,disulfide bond-containing lipid-PEG(DSPESS-PEG2K) modified chain architecture-engineered ART derivatives nanoassemblies(NAs) were developed to mitigate solubility-related limitations while enhancing targeting precision.Molecular docking and experimental validation demonstrated that ART derivatives inhibited LONP1 through hydrophobic interactions while preserved Fe^(2+)-mediated Fenton-like reaction activity.In vitro and in vivo evaluations demonstrated that AC_(15)-C NAs outperformed free ART and other NAs,suppressing 4T1 tumor growth via dual action:LONP1-directed mitochondrial proteostasis collapse and reactive oxygen species(ROS) amplification through Fe^(2+)-ART interactions.This study elucidated a novel anti-tumor mechanism of ART through the rational design of derivatives with spatially configured aliphatic chains,and developed reductionresponsive NAs to provide an advanced delivery strategy.
文摘Purpose-This study explores how managerial leadership and organizational innovation interact to enhance resilience and risk management in railway supply chains and how these capabilities contribute to sustained competitive advantage.It emphasizes the strategic importance of resilience in railway systems that face operational complexity,regulatory pressures and increasing exposure to systemic risks.Design/methodology/approach-A mixed-methods design was employed,integrating survey data from 186 railway organizations with six case studies involving railway operators,rolling stock manufacturers and supply chain partners across multiple regions.Constructs were measured using validated scales and hypothesized relationships were tested using Structural Equation Modeling(SEM).Case study interviews were analyzed thematically to provide contextual understanding of leadership practices and innovation strategies.Findings-The results confirm that transformational managerial leadership significantly predicts innovation adoption,which in turn strengthens resilience and risk management capabilities.Resilience emerged as a powerful driver of competitive advantage,reinforcing its role as a strategic capability rather than a reactive response to disruptions.Furthermore,innovation was shown to partially mediate the relationship between leadership and resilience,highlighting its function as the operational channel through which vision translates into capability.Originality/value-This study contributes to the literature by integrating the Resource-Based View(RBV)and Dynamic Capabilities(DC)framework into the context of railway supply chains.It is among the first to empirically validate the mediating role of innovation between leadership and resilience,offering both theoretical advancements and actionable strategies for building resilient and competitive railway systems.
基金supported by the Natural Science Foundation of Fujian Province of China(2025J01380)National Natural Science Foundation of China(No.62471139)+3 种基金the Major Health Research Project of Fujian Province(2021ZD01001)Fujian Provincial Units Special Funds for Education and Research(2022639)Fujian University of Technology Research Start-up Fund(GY-S24002)Fujian Research and Training Grants for Young and Middle-aged Leaders in Healthcare(GY-H-24179).
文摘The generation of synthetic trajectories has become essential in various fields for analyzing complex movement patterns.However,the use of real-world trajectory data poses significant privacy risks,such as location reidentification and correlation attacks.To address these challenges,privacy-preserving trajectory generation methods are critical for applications relying on sensitive location data.This paper introduces DPIL-Traj,an advanced framework designed to generate synthetic trajectories while achieving a superior balance between data utility and privacy preservation.Firstly,the framework incorporates Differential Privacy Clustering,which anonymizes trajectory data by applying differential privacy techniques that add noise,ensuring the protection of sensitive user information.Secondly,Imitation Learning is used to replicate decision-making behaviors observed in real-world trajectories.By learning from expert trajectories,this component generates synthetic data that closely mimics real-world decision-making processes while optimizing the quality of the generated trajectories.Finally,Markov-based Trajectory Generation is employed to capture and maintain the inherent temporal dynamics of movement patterns.Extensive experiments conducted on the GeoLife trajectory dataset show that DPIL-Traj improves utility performance by an average of 19.85%,and in terms of privacy performance by an average of 12.51%,compared to state-of-the-art approaches.Ablation studies further reveal that DP clustering effectively safeguards privacy,imitation learning enhances utility under noise,and the Markov module strengthens temporal coherence.
文摘China releases first standards system for humanoid robots and embodied intelligence The Annual Meeting of Humanoid and Embodied Intelligence Standardization(HEIS)was held on February 28 in Beijing.The 2026 version of the standards system for humanoid robots and embodied intelligence was released at the meeting,which is the first top-level design of standards for the entire industrial chain and lifecycle of humanoid robots and embodied intelligence in China,marking that the related industries are embarking on a new chapter of standardized development.
