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Simulation of temporal and spatial change of N_2O emissions in the Yangtze River Delta

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Journal of Environmental Sciences 2005年第4期17卷 686-690页

作者： LIUJian-dong ZHOUXiu-ji CHENDe-liang ouyangzhi-yun WANGXiao-ke AchbergerChristine EarthScienceCenter GothenburgUniversitySweden／／ChineseAcademyofMeteorologicalSciencesBeijing100081China ChineseAcademyofMeteorologicalSciences Beijing100081China EarthScienceCenter GothenburgUniversitySweden／／Laborato~forClimateStudies／NationalClimateCenterChinaMeteorologicalAdministrationBeijing100081China ResearchCenterforEco-EnvironmentalSciences ChineseAcademyofSciencesBeijing100085China EarthScienceCenter GothenburgUniversitySweden

A biogeochemical model(DNDC) is combined with a plant ecological model to estimate N_2O emission from rice paddy fields in the Yangtze River Delta region. The model is driven by local meteorological, soil, and physiological data and is validated for 1999 and 2000 at a site in the region, which showed that the simulated N_2O emissions agree fairly well with the observed data. This adds some confidence in the estimated N_2O emissions during 1950 and 2000 in the Hangzhou Region. A significant correlation between the N_2O emissions and the population for the Hangzhou Region is found, which is due to a combination of increased application of fertilizers and cultivated area. Such a correlation can not be established for the whole Yangtze River Delta region when the data of both urban and rural areas are included. However, when the data from the heavily urbanized areas are excluded, a significant correlation between population and N_2O emissions emerges. The results show clearly that both the temporal and the spatial N_2O emissions have significant positive relationship with population under traditional farming practice. These results have implications for suitable mitigation options towards a sustainable agriculture and environment in this region.

关键词： simulation temporal and spatial N_2O emissions Yangtze River Delta,China

Ecological Behavior of Linear Alkylbenzene Sulfonate (LAS) in Soil-Plant Systems

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Pedosphere 2005年第2期15卷 216-224页

作者： JIALiang-Qing OUZi-Qing ouyangzhi-yun ResearchCenterforEco-EnvironmentalSciences ChineseAcademyofSciencesBeijing100085（China）／／AnhuiAcademyofEnvironmentalSciencesHefei230061（China） InstituteofAppliedEcology ChineseAcademyofSciencesShenyang100016（China） ResearchCenterforEco-EnvironmentalSciences ChineseAcademyofSciencesBeijing100085（China）

More and more linear alkylbenzene sulfonate (LAS) has contaminated the water and soil ma pollution discharge, making it important to identify the ecological behavior and toxicity of LAS so as to carry out measures that will reduce its negative effects on the ecosystem. The ecological behavior of LAS. including degradation, migration, and plant uptake, in both soil-paddy rice and soil-soybean systems was studied. Reduction of LAS in pot and field plots followed the first order reaction kinetics with degradation half-lives of 35-50 days with LAS decreasing to very low concentrations after a season of crop growth. Strong migration ability for LAS was found and the breakthrough time in a 1.5 in soil monolith was significantly shortened to 23 days by preferential flow. Leachate volumes of soil-paddy and soil-soybean systems at preferential breakthrough were much different, while the leachate volumes at equilibrium governed by soil adsorption/desorption processes were very similar. Significant uptake of LAS in both paddy rice and sovbeans was observed in pot and field experiments (P < 0.05). In aquatic culture, 20 μg mL-1 and above of LAS significantly inhibited the growth of paddy seedlings (P < 0.05). The critical concentration for LAS in soil inhibiting the growth and yield of paddy was 160 μg g-1; when higher, there was a strong negative influence, with decreases in height, spike length, and production, when lower than 80 μg g-1, paddy growth was stimulated. There was little effect of LAS on soybeans.

关键词： degradation ecological behavior linear alkylbenzene sulfonate migration preferential flow

Target Search and Navigation in Heterogeneous Robot Systems with Deep Reinforcement Learning

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Machine Intelligence Research 2025年第1期22卷 79-90页

作者： yun Chen Jiaping Xiao Department of Mechanical Engineering University of AlabamaTuscaloosa35487USA School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore639798Singapore

Collaborative heterogeneous robot systems can greatly enhance the efficiency of target search and navigation *** this paper,we design a heterogeneous robot system consisting of an unmanned aerial vehicle(UAV)and an unmanned ground vehicle(UGV)for search and rescue missions in unknown *** system is able to search for targets and navigate to them in a maze-like mine environment with the policies learned through deep reinforcement learning *** the training process,if two robots are trained simultaneously,the rewards related to their collaboration may not be properly ***,we introduce a multi-stage reinforcement learning framework and a curiosity module to encourage agents to explore unvisited *** in simulation environments show that our framework can train the heterogeneous robot system to achieve the search and navigation with unknown target locations while existing baselines may *** UGV achieves a success rate of 89.1%in the mission within the original environment,and maintains a 67.6%success rate in untrained complex environments.

关键词： Heterogeneous intelligent systems deep reinforcement learning multiagent systems robot learning target search

Value Iteration-Based Distributed Adaptive Dynamic Programming for Multi-Player Differential Game With Incomplete Information

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IEEE/CAA Journal of Automatica Sinica 2025年第2期12卷 436-447页

作者： yun Zhang Yuqi Wang yunze Cai the Department of Automation Shanghai Jiao Tong University the Key Laboratory of System Control and Information Processing Ministry of Education of China the National Key Laboratory of Air-based Information Perception and Fusion

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.

关键词： Distributed adaptive dynamic programming incomplete information multi-player differential game (MPDG) value iteration

Advancing gravitational theory through the tetrahedral constellation gravitational wave observatory

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 197-198页

作者： yun-Yong Wang Zhou-Jian Cao Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing102206China

The Tetrahedral Constellation Gravitational Wave Observatory(TEGO)[1]represents a significant leap forward in gravitational wave detection,advancing our understanding of gravitational *** introducing a fourth spacecraft to form a tetrahedral configuration,TEGO enhances traditional triangular setups,enabling the simultaneous sensitivity to all six gravitational wave polarization modes,including those not predicted by general relativity.

关键词： wave polarization theory

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Sex-dependent alterations in extracellular vesicles linking chronic spinal cord injury to brain neuroinflammation and neurodegeneration

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Neural Regeneration Research 2025年第2期20卷 483-484页

作者： yun Li Junfang Wu Department of Anesthesiology&Shock Trauma and Anesthesiology Research(STAR)CenterUniversity of Maryland School of MedicineBaltimoreMDUSA

Traumatic spinal cord injury(SCI)is a devastating exogenous injury with long-lasting consequences and a leading cause of death and disability *** in assistive technology,rehabilitative interventions,and the ability to identify and intervene in secondary conditions have significantly increased the long-term survival rate of SCI patients,with some people even living well into their seventh or eighth *** survival changes have led neurotrauma researchers to examine how SCI interacts with brain *** health and epidemiological data showed that patients with long-term SCI can have a lower life expectancy and quality of life,along with a higher risk of comorbidities and complications.

关键词： alterations inflammation injury

Aluminum foam as buffer layer used in soft rock tunnel with large deformation

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Journal of Mountain Science 2025年第1期22卷 324-336页

作者： WU Faquan MIAO Binxin TIAN yun ZHANG Fang ZHANG Chaoxuan School of Civil Engineering Shaoxing UniversityShaoxing 312000China Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province Shaoxing 312000China School of Civil Engineering and Architecture Taizhou UniversityTaizhou 318000China

The squeezing deformation of surrounding rock is an important factor restricting the safe construction and long-term operation of tunnels when a tunnel passes through soft strata with high ground *** such soft rock geological conditions,the large deformation of the surrounding rock can easily lead to the failure of supporting structures,including shotcrete cracks,spalling,and steel arch *** improve the lining support performance during the large deformation of squeezed surrounding rock,this work selects aluminum foam with densities of 0.25 g/cm3,0.42 g/cm3 and 0.61 g/cm3 as the buffer layer material and carries out uniaxial confined compression *** the evaluation and analysis of energy absorption and the comparison of the yield pressure of aluminum foam with those of other cushioning materials and yield pressure support systems,the strength,deformation and energy absorption of aluminum foam with a density of 0.25 g/cm3 meet the yield pressure performance *** numerical model of the buffer layer yielding support system is then established via the finite element analysis software ABAQUS,and the influence of the buffer layer setting on the lining support is *** with the conventional support scheme,the addition of an aluminum foam buffer layer can reduce the stress and deformation of the primary support and secondary *** maximum and minimum principal stresses of the primary support are reduced by 13%and 15%,*** maximum and minimum principal stresses of the secondary lining are reduced by 15%and 12%,respectively,and the displacement deformation of the secondary lining position is reduced by 15%.In summary,the application of aluminum foam buffer layer can reduce the stress and deformation of the primary support and secondary lining,improve the stress safety of the support and reduce the deformation of the support.

关键词： Soft rock tunnel Uniaxial confined compression Aluminum foam Buffer layer Yielding support

Mitophagy in acute central nervous system injuries:regulatory mechanisms and therapeutic potentials

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Neural Regeneration Research 2025年第9期20卷 2437-2453页

作者： Siyi Xu Junqiu Jia Rui Mao Xiang Cao yun Xu Department of Neurology Nanjing Drum Tower HospitalClinical College of Jiangsu UniversityNanjingJiangsu ProvinceChina Department of Neurology Nanjing Drum Tower HospitalChinese Academy of Medical Science&Peking Union Medical CollegeNanjingJiangsu ProvinceChina Department of Neurology Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingJiangsu ProvinceChina State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases Nanjing UniversityNanjingJiangsu ProvinceChina Jiangsu Key Laboratory for Molecular Medicine Medical School of Nanjing UniversityNanjingJiangsu ProvinceChina Nanjing Neurology Medical Center NanjingJiangsu ProvinceChina

Acute central nervous system injuries,including ischemic stro ke,intracerebral hemorrhage,subarachnoid hemorrhage,traumatic brain injury,and spinal co rd injury,are a major global health *** optimal therapies and improving the long-term neurological functions of patients with acute central nervous system injuries are urgent *** are susceptible to damage after acute central nervous system injury,and this leads to the release of toxic levels of reactive oxygen species,which induce cell ***,a selective form of autophagy,is crucial in eliminating redundant or damaged mitochondria during these *** evidence has highlighted the significant role of mitophagy in acute central nervous system *** this review,we provide a comprehensive overview of the process,classification,and related mechanisms of *** also highlight the recent developments in research into the role of mitophagy in various acute central nervous system injuries and drug therapies that regulate *** the final section of this review,we emphasize the potential for treating these disorders by focusing on mitophagy and suggest future research paths in this area.

关键词： autophagy intracerebral hemorrhage ischemic stroke mitochondria mitochondrial biogenesis mitochondrial quality control mitophagy spinal cord injury subarachnoid hemorrhage traumatic brain injury

IoT Empowered Early Warning of Transmission Line Galloping Based on Integrated Optical Fiber Sensing and Weather Forecast Time Series Data

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Computers, Materials & Continua 2025年第1期82卷 1171-1192页

作者： Zhe Li yun Liang Jinyu Wang Yang Gao State Grid Henan Electric Power Company Electric Power Scientific Research Institute State Grid Henan Electric Power CompanyZhengzhou450052China

Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power *** early warning methods of iced transmission line galloping suffer from issues such as reliance on a single data source,neglect of irregular time series,and lack of attention-based closed-loop feedback,resulting in high rates of missed and false *** address these challenges,we propose an Internet of Things(IoT)empowered early warning method of transmission line galloping that integrates time series data from optical fiber sensing and weather ***,the method applies a primary adaptive weighted fusion to the IoT empowered optical fiber real-time sensing data and weather forecast data,followed by a secondary fusion based on a Back Propagation(BP)neural network,and uses the K-medoids algorithm for clustering the fused ***,an adaptive irregular time series perception adjustment module is introduced into the traditional Gated Recurrent Unit(GRU)network,and closed-loop feedback based on attentionmechanism is employed to update network parameters through gradient feedback of the loss function,enabling closed-loop training and time series data prediction of the GRU network ***,considering various types of prediction data and the duration of icing,an iced transmission line galloping risk coefficient is established,and warnings are categorized based on this ***,using an IoT-driven realistic dataset of iced transmission line galloping,the effectiveness of the proposed method is validated through multi-dimensional simulation scenarios.

关键词： Optical fiber sensing multi-source data fusion early warning of galloping time series data IoT adaptive weighted learning irregular time series perception closed-loop attention mechanism