Land consolidation has a profound impact on landscape patterns and ecological functions at various scales through engineering and biological measures. In recent years, China invests more than 100 billion RMB yuan on l...Land consolidation has a profound impact on landscape patterns and ecological functions at various scales through engineering and biological measures. In recent years, China invests more than 100 billion RMB yuan on land consolidation each year. To under- stand how land consolidation affects landscape patterns and ecosystems, we investigated the ecosystem service value and the ecological connectivity in a consolidated area of Da＇an city from 2008 to 2014 using a revised ecological connectivity index. The results indicated that land consolidation has certain negative influences on the ecosystem services in this area. The total ecosystem service value will decrease by nearly 30% in the late stage of consolida- tion. This decrease is caused by the loss of ecosystem service of the wetland and grassland, despite a sensible increase of cultivated land. In addition, land consolidation could change the ecological connectivity as well as the land use structure. Up to 85% of the entire area will be in low connectivity in the late stage of consolidation, representing a 6.23% increase in the total coverage compared to pre-consolidation. Finally, the different connectivity landscape and their key areas can be identified by the revised ecological connectivity index effectively. This study is helpful to trace out the relationships between landscape pattern and ecological process, and provides insights for ecological planning and designing of land consolidation in this area. We suggest that more attentions should be paid to improve the quality and eco- system service value per unit area of the landscape, to establish ecological compensation mechanism of wetland losses, and to create the ecological corridors along the least accu- mulated impendence surface in the key areas during land consolidation.展开更多
Based on the partition function in statistical thermodynamics, atomic partit ion parameter fi =lg[(ni－1)0.5·Ar,i] is introduced in this paper. The fi has demonstrated good unitarity for all the ground state ato ...Based on the partition function in statistical thermodynamics, atomic partit ion parameter fi =lg[(ni－1)0.5·Ar,i] is introduced in this paper. The fi has demonstrated good unitarity for all the ground state ato ms, and excellent correlativity with the standard entropies (,J·mol－1·K －1) of 70 cations in solid compounds: = －10.247＋27.508 fi , r=0.996. A satisfactory curve equation is developed as follows: =6.229＋13.257 fi1.5, r= 0.999. On the basis of adjacency matrices and fi , a novel partition connectivit y index is developed for the study on the standard entropies of 64 S block compo unds. The linear regression equation is set up by the least square method: =－3 9.416＋33.9610H, r=0.985. The binary linear equation among and 0H, nM (princip al quantum number of the ground state atoms for S block) is drawn up: =－21.591 ＋32.0720H－31.013nM－1, R=0.990. The calculated values of basically tally w ith the experiment values. fi and 0H demonstrate that the method possesses the a dvantage of easy computation and clear physical significance.展开更多
Patients with mild traumatic brain injury have a diverse clinical presentation,and the underlying pathophysiology remains poorly understood.Magnetic resonance imaging is a non-invasive technique that has been widely u...Patients with mild traumatic brain injury have a diverse clinical presentation,and the underlying pathophysiology remains poorly understood.Magnetic resonance imaging is a non-invasive technique that has been widely utilized to investigate neuro biological markers after mild traumatic brain injury.This approach has emerged as a promising tool for investigating the pathogenesis of mild traumatic brain injury.G raph theory is a quantitative method of analyzing complex networks that has been widely used to study changes in brain structure and function.However,most previous mild traumatic brain injury studies using graph theory have focused on specific populations,with limited exploration of simultaneous abnormalities in structural and functional connectivity.Given that mild traumatic brain injury is the most common type of traumatic brain injury encounte red in clinical practice,further investigation of the patient characteristics and evolution of structural and functional connectivity is critical.In the present study,we explored whether abnormal structural and functional connectivity in the acute phase could serve as indicators of longitudinal changes in imaging data and cognitive function in patients with mild traumatic brain injury.In this longitudinal study,we enrolled 46 patients with mild traumatic brain injury who were assessed within 2 wee ks of injury,as well as 36 healthy controls.Resting-state functional magnetic resonance imaging and diffusion-weighted imaging data were acquired for graph theoretical network analysis.In the acute phase,patients with mild traumatic brain injury demonstrated reduced structural connectivity in the dorsal attention network.More than 3 months of followup data revealed signs of recovery in structural and functional connectivity,as well as cognitive function,in 22 out of the 46 patients.Furthermore,better cognitive function was associated with more efficient networks.Finally,our data indicated that small-worldness in the acute stage could serve as a predictor of longitudinal ch展开更多
Double-integrator multi-agent systems(MASs)might not achieve dynamical consensus,even if only partial agents suffer from self-sensing function failures(SSFFs).SSFFs might be asynchronous in real engineering applicatio...Double-integrator multi-agent systems(MASs)might not achieve dynamical consensus,even if only partial agents suffer from self-sensing function failures(SSFFs).SSFFs might be asynchronous in real engineering application.The existing fault-tolerant dynamical consensus protocol suitable for synchronous SSFFs cannot be directly used to tackle fault-tolerant dynamical consensus of double-integrator MASs with partial agents subject to asynchronous SSFFs.Motivated by these facts,this paper explores a new fault-tolerant dynamical consensus protocol suitable for asynchronous SSFFs.First,multi-hop communication together with the idea of treating asynchronous SSFFs as multiple piecewise synchronous SSFFs is used for recovering the connectivity of network topology among all normal agents.Second,a fault-tolerant dynamical consensus protocol is designed for double-integrator MASs by utilizing the history information of an agent subject to SSFF for computing its own state information at the instants when its minimum-hop normal neighbor set changes.Then,it is theoretically proved that if the strategy of network topology connectivity recovery and the fault-tolerant dynamical consensus protocol with proper time-varying gains are used simultaneously,double-integrator MASs with all normal agents and all agents subject to SSFFs can reach dynamical consensus.Finally,comparison numerical simulations are given to illustrate the effectiveness of the theoretical results.展开更多
The three-phase Enriched Environment(EE)paradigm has been shown to promote post-stroke functional improvement,but the neuronal mechanisms are still unclear.In this study,we applied a multimodal neuroimaging protocol c...The three-phase Enriched Environment(EE)paradigm has been shown to promote post-stroke functional improvement,but the neuronal mechanisms are still unclear.In this study,we applied a multimodal neuroimaging protocol combining magnetic resonance imaging(MRI)and positron emission tomography(PET)to examine the effects of post-ischemic EE treatment on structural and functional neuroplasticity in the bilateral sensorimotor cortex.Rats were subjected to permanent middle cerebral artery occlusion.The motor function of the rats was examined using the DigiGait test.MRI was applied to investigate the EE-induced structural modifications of the bilateral sensorimotor cortex.[^(18)F]-fluorodeoxyglucose PET was used to detect glucose metabolism.Blood oxygen level-dependent(BOLD)-functional MRI(fMRI)was used to identify the regional brain activity and functional connectivity(FC).In addition,the expression of neuroplasticity-related signaling pathways including neurotrophic factors(BDNF/CREB),axonal guidance proteins(Robo1/Slit2),and axonal growth-inhibitory proteins(NogoA/NgR)as well as downstream proteins(RhoA/ROCK)in the bilateral sensorimotor cortex were measured by Western blots.Our results showed the three-phase EE improved the walking ability.Structural T2 mapping imaging and diffusion tensor imaging demonstrated that EE benefited structure integrity in the bilateral sensorimotor cortex.PET-MRI fused images showed improved glucose metabolism in the corresponding regions after EE intervention.Specifically,the BOLD-based amplitude of low-frequency fluctuations showed that EE increased spontaneous activity in the bilateral motor cortex and ipsilateral sensory cortex.In addition,FC results showed increased sensorimotor connectivity in the ipsilateral hemisphere and increased interhemispheric motor cortical connectivity and motor cortical-thalamic connectivity following EE intervention.In addition,a strong correlation was found between increased functional connectivity and improved motor performance of limbs.Specifically,EE re展开更多
In this paper,the problem of adaptive finite time formation control is investigated for double integrator multi-agent systems with uncertainties.Firstly,considering the multi-agent systems with uncertain dynamic refer...In this paper,the problem of adaptive finite time formation control is investigated for double integrator multi-agent systems with uncertainties.Firstly,considering the multi-agent systems with uncertain dynamic reference and external bounded disturbance,a distributed adaptive estimator control algorithm is designed to realize formation tracking control in finite-time.It is important that the collision avoidance and maintaining connectivity of the multi-agent systems are realized by constructing an effective potential function based on distance constraints.On the other hand,the problem of formation production control for the double integrator systems is discussed with desired formation shape in finite-time.Achieving four control objectives is the main contributions in all the phases,including the estimation of uncertainties,collision avoidance,connectivity maintenance,and finite-time convergence.Finally,an application example of the formation production control is presented to verify accuracy of the proposed theoretical method.展开更多
基金National Natural Science Foundation of China, No.41171152
文摘Land consolidation has a profound impact on landscape patterns and ecological functions at various scales through engineering and biological measures. In recent years, China invests more than 100 billion RMB yuan on land consolidation each year. To under- stand how land consolidation affects landscape patterns and ecosystems, we investigated the ecosystem service value and the ecological connectivity in a consolidated area of Da＇an city from 2008 to 2014 using a revised ecological connectivity index. The results indicated that land consolidation has certain negative influences on the ecosystem services in this area. The total ecosystem service value will decrease by nearly 30% in the late stage of consolida- tion. This decrease is caused by the loss of ecosystem service of the wetland and grassland, despite a sensible increase of cultivated land. In addition, land consolidation could change the ecological connectivity as well as the land use structure. Up to 85% of the entire area will be in low connectivity in the late stage of consolidation, representing a 6.23% increase in the total coverage compared to pre-consolidation. Finally, the different connectivity landscape and their key areas can be identified by the revised ecological connectivity index effectively. This study is helpful to trace out the relationships between landscape pattern and ecological process, and provides insights for ecological planning and designing of land consolidation in this area. We suggest that more attentions should be paid to improve the quality and eco- system service value per unit area of the landscape, to establish ecological compensation mechanism of wetland losses, and to create the ecological corridors along the least accu- mulated impendence surface in the key areas during land consolidation.
文摘Based on the partition function in statistical thermodynamics, atomic partit ion parameter fi =lg[(ni－1)0.5·Ar,i] is introduced in this paper. The fi has demonstrated good unitarity for all the ground state ato ms, and excellent correlativity with the standard entropies (,J·mol－1·K －1) of 70 cations in solid compounds: = －10.247＋27.508 fi , r=0.996. A satisfactory curve equation is developed as follows: =6.229＋13.257 fi1.5, r= 0.999. On the basis of adjacency matrices and fi , a novel partition connectivit y index is developed for the study on the standard entropies of 64 S block compo unds. The linear regression equation is set up by the least square method: =－3 9.416＋33.9610H, r=0.985. The binary linear equation among and 0H, nM (princip al quantum number of the ground state atoms for S block) is drawn up: =－21.591 ＋32.0720H－31.013nM－1, R=0.990. The calculated values of basically tally w ith the experiment values. fi and 0H demonstrate that the method possesses the a dvantage of easy computation and clear physical significance.
基金supported by the National Natural Science Foundation of China,Nos.81671671(to JL),61971451(to JL),U22A2034(to XK),62177047(to XK)the National Defense Science and Technology Collaborative Innovation Major Project of Central South University,No.2021gfcx05(to JL)+6 种基金Clinical Research Cen terfor Medical Imaging of Hunan Province,No.2020SK4001(to JL)Key Emergency Project of Pneumonia Epidemic of Novel Coronavirus Infection of Hu nan Province,No.2020SK3006(to JL)Innovative Special Construction Foundation of Hunan Province,No.2019SK2131(to JL)the Science and Technology lnnovation Program of Hunan Province,Nos.2021RC4016(to JL),2021SK53503(to ML)Scientific Research Program of Hunan Commission of Health,No.202209044797(to JL)Central South University Research Program of Advanced Interdisciplinary Studies,No.2023Q YJC020(to XK)the Natural Science Foundation of Hunan Province,No.2022JJ30814(to ML)。
文摘Patients with mild traumatic brain injury have a diverse clinical presentation,and the underlying pathophysiology remains poorly understood.Magnetic resonance imaging is a non-invasive technique that has been widely utilized to investigate neuro biological markers after mild traumatic brain injury.This approach has emerged as a promising tool for investigating the pathogenesis of mild traumatic brain injury.G raph theory is a quantitative method of analyzing complex networks that has been widely used to study changes in brain structure and function.However,most previous mild traumatic brain injury studies using graph theory have focused on specific populations,with limited exploration of simultaneous abnormalities in structural and functional connectivity.Given that mild traumatic brain injury is the most common type of traumatic brain injury encounte red in clinical practice,further investigation of the patient characteristics and evolution of structural and functional connectivity is critical.In the present study,we explored whether abnormal structural and functional connectivity in the acute phase could serve as indicators of longitudinal changes in imaging data and cognitive function in patients with mild traumatic brain injury.In this longitudinal study,we enrolled 46 patients with mild traumatic brain injury who were assessed within 2 wee ks of injury,as well as 36 healthy controls.Resting-state functional magnetic resonance imaging and diffusion-weighted imaging data were acquired for graph theoretical network analysis.In the acute phase,patients with mild traumatic brain injury demonstrated reduced structural connectivity in the dorsal attention network.More than 3 months of followup data revealed signs of recovery in structural and functional connectivity,as well as cognitive function,in 22 out of the 46 patients.Furthermore,better cognitive function was associated with more efficient networks.Finally,our data indicated that small-worldness in the acute stage could serve as a predictor of longitudinal ch
基金National Natural Science Foundation of China(No.61876073)Fundamental Research Funds for the Central Universities of China(No.JUSRP21920)。
文摘Double-integrator multi-agent systems(MASs)might not achieve dynamical consensus,even if only partial agents suffer from self-sensing function failures(SSFFs).SSFFs might be asynchronous in real engineering application.The existing fault-tolerant dynamical consensus protocol suitable for synchronous SSFFs cannot be directly used to tackle fault-tolerant dynamical consensus of double-integrator MASs with partial agents subject to asynchronous SSFFs.Motivated by these facts,this paper explores a new fault-tolerant dynamical consensus protocol suitable for asynchronous SSFFs.First,multi-hop communication together with the idea of treating asynchronous SSFFs as multiple piecewise synchronous SSFFs is used for recovering the connectivity of network topology among all normal agents.Second,a fault-tolerant dynamical consensus protocol is designed for double-integrator MASs by utilizing the history information of an agent subject to SSFF for computing its own state information at the instants when its minimum-hop normal neighbor set changes.Then,it is theoretically proved that if the strategy of network topology connectivity recovery and the fault-tolerant dynamical consensus protocol with proper time-varying gains are used simultaneously,double-integrator MASs with all normal agents and all agents subject to SSFFs can reach dynamical consensus.Finally,comparison numerical simulations are given to illustrate the effectiveness of the theoretical results.
基金supported by the National Natural Science Foundation of China(82174471).
文摘The three-phase Enriched Environment(EE)paradigm has been shown to promote post-stroke functional improvement,but the neuronal mechanisms are still unclear.In this study,we applied a multimodal neuroimaging protocol combining magnetic resonance imaging(MRI)and positron emission tomography(PET)to examine the effects of post-ischemic EE treatment on structural and functional neuroplasticity in the bilateral sensorimotor cortex.Rats were subjected to permanent middle cerebral artery occlusion.The motor function of the rats was examined using the DigiGait test.MRI was applied to investigate the EE-induced structural modifications of the bilateral sensorimotor cortex.[^(18)F]-fluorodeoxyglucose PET was used to detect glucose metabolism.Blood oxygen level-dependent(BOLD)-functional MRI(fMRI)was used to identify the regional brain activity and functional connectivity(FC).In addition,the expression of neuroplasticity-related signaling pathways including neurotrophic factors(BDNF/CREB),axonal guidance proteins(Robo1/Slit2),and axonal growth-inhibitory proteins(NogoA/NgR)as well as downstream proteins(RhoA/ROCK)in the bilateral sensorimotor cortex were measured by Western blots.Our results showed the three-phase EE improved the walking ability.Structural T2 mapping imaging and diffusion tensor imaging demonstrated that EE benefited structure integrity in the bilateral sensorimotor cortex.PET-MRI fused images showed improved glucose metabolism in the corresponding regions after EE intervention.Specifically,the BOLD-based amplitude of low-frequency fluctuations showed that EE increased spontaneous activity in the bilateral motor cortex and ipsilateral sensory cortex.In addition,FC results showed increased sensorimotor connectivity in the ipsilateral hemisphere and increased interhemispheric motor cortical connectivity and motor cortical-thalamic connectivity following EE intervention.In addition,a strong correlation was found between increased functional connectivity and improved motor performance of limbs.Specifically,EE re
基金work was supported by the National Natural Science Foundation of China(Grant Nos.11962019,11932003,11602115,11602146 and 11802006)the Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(Grant No.NJYT-17-B33)+1 种基金the Beijing Natural Science Foundation(Grant No.1194024)and the Fundamental Research Funds for the Central。
文摘In this paper,the problem of adaptive finite time formation control is investigated for double integrator multi-agent systems with uncertainties.Firstly,considering the multi-agent systems with uncertain dynamic reference and external bounded disturbance,a distributed adaptive estimator control algorithm is designed to realize formation tracking control in finite-time.It is important that the collision avoidance and maintaining connectivity of the multi-agent systems are realized by constructing an effective potential function based on distance constraints.On the other hand,the problem of formation production control for the double integrator systems is discussed with desired formation shape in finite-time.Achieving four control objectives is the main contributions in all the phases,including the estimation of uncertainties,collision avoidance,connectivity maintenance,and finite-time convergence.Finally,an application example of the formation production control is presented to verify accuracy of the proposed theoretical method.
