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Monitoring of ecological security patterns based on long-term land use changes in Langsa Bay, Indonesia

International Journal of Digital Earth 2025年第1期18卷

作者： Zhang, Jiaojie Yan, Fengqin Lyne, Vincent Wang, Xuege Su, Fenzhen Cao, Qian He, Bin School of Geography and Information Engineering China University of Geosciences Wuhan China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China College of Resources and Environment University of Chinese Academy of Science Beijing China IMAS-Hobart University of Tasmania Tasmania Australia School of Earth Sciences and Engineering Hohai University Nanjing China School of Geography and Ocean Sciences Nanjing University Nanjing China

Southeast Asian coastal zone boasts a concentration of land and marine resources with vulnerable habitats, especially in highly artificial bays. Yet systematic studies on their ecological security assessment are lacking. To investigate the dynamic relationship between land use and ecological security patterns (ESP) in Langsa Bay, we assessed the ESPs for 2002–2023 and four scenarios for 2030 by satellite remote-sensing time series images. We coupled the RF-GLCM algorithm and the InVEST-PLUS model to simulate ecological services. Realizing the ESP construction and relationship dynamics analysis by circuit theory model and ecological security index (ESI) evaluation system. The approach improves the identification of ecological sources, corridors and nodes, providing an explicit spatial framework for conservation prioritization. Results showed that land-use changes strongly influenced ESP, with a 37.55 km2 increase in construction and a 159.78 km2 decrease in forest. Orchards increased by 201.79 km2, leading to a drastic decrease in forest and cropland. Future scenarios suggested that ecological and cropland protections (ESI: 4.56 and 1.98) enhance ecological security, whereas economic development (ESI: −1.20) reduces it. The findings emphasize prioritizing ecological and agricultural land preservation to mitigate ecological risks in bays, offering spatial, temporal and land-use insights for sustainable coastal management. © 2025 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

关键词： Biotic

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Numerical simulation of Random Close Packing with Tetrahedra

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Chinese Physics Letters 2008年第5期25卷 1724-1726页

作者：李水乡赵健周璇 College of Engineering Peking University Beijing 100871 State Key Laboratory for Turbulence and Complex System Study Peking University Beijing 100871

The densest packing of tetrahedra is still an unsolved problem. Numerical simulations of random close packing of tetrahedra are carried out with a sphere assembly model and improved relaxation algorithm. The packing density and average contact number obtained for random close packing of regular tetrahedra is 0.6817 and 7.21 respectively, while the values of spheres are 0.6435 and 5.95. The simulation demonstrates that tetrahedra can be randomly packed denser than spheres. Random close packings of tetrahedra with a range of height are simulated as well. We find that the regular tetrahedron might be the optimal shape which gives the highest packing density of tetrahedra.

关键词： supernova explosion proto-neutron star shock wave

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Spatiotemporal Distribution Characteristics of Actual Evapotranspiration over Long-term Changes on the Mongolian Plateau

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Journal of Resources and Ecology 2025年第1期16卷 11-21页

作者： SU Yuhui WANG Juanle HAN Baomin Ochir ALTANSUKH Davaadorj DAVAASUREN School of Civil engineering and geomatics Shandong University of TechnologyZiboShandong 255049China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023China Department of Environment and Forest Engineering School of Engineering and Technology and Environmental engineering laboratoryNational University of MongoliaUlaanbaatar 14201Mongolia Department of Geography School of Art and SciencesNational University of MongoliaUlaanbaatar 14201Mongolia

Evapotranspiration(ET)is of great significance for the ecological environment and water resource utilization in arid and semi-arid *** Mongolian Plateau,owing to drought,low rainfall,and extremely uneven distribution of water resources,has a typical temperate continental climate.A refined understanding of the spatiotemporal distribution of ET in this region will help in establishing regulatory strategies for climate change responses,regional livestock regulation,and grassland degradation *** this study,meteorological station data,precipitation data,and the Penman-Monteith model were used to study the temporal and spatial distribution characteristics of actual ET over the Mongolian Plateau from 2011 to *** found that:(1)The spatial distribution of ET in the Mongolian Plateau showed a high trend in the north and east and a low trend in the middle and *** was a significant difference in the regional annual ET,with the highest ET reaching over 500 mm and the lowest being only approximately 70 mm.(2)The annual ET values in 2013,2018,and 2019 were relatively large,varying between 80 and 500 mm,and the overall ET of the Mongolian Plateau first decreased,then increased,and then decreased.(3)The temporal distribution exhibits a unimodal trend of increasing and then decreasing,with July being the turning ***-September was a period of high ET,with the highest ET exceeding 100 *** vegetation coverage was high,precipitation was abundant,and the vegetation ET effect was *** was a period of low ET,with a maximum ET of approximately 10 mm in January and December;the ET for the month with the lowest value was approximately *** quantitative inversion method proposed in this study can provide method and data support for north and central Asia,and other large arid and semi-arid areas.

关键词： Penman-Monteith model actual evapotranspiration Pearson correlation analysis precipitation Mongolian Plateau

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Sub/supercritical carbon dioxide induced phase switching for the reaction and separation in ILs/methanol

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Green Energy & Environment 2016年第2期1卷 144-148页

作者： Jiayu Xin Dongxia Yan Ruimei Cao Xingmei Lu Huixian Dong Suojiang Zhang Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences

Separation of products from ionic liquid(IL) solvents is one of the main challenges that hinder their utilizations. In this study, the production of γ-valerolactone(GVL) by selective hydrogenation of α-angelica lactone(AL) and separation of the products from the IL solvent were carried out by using subcritical CO_2 as a "switch" at room temperature. After the mixture was separated into two phases by subcritical CO_2, AL and nano Pd/C catalyst were only found in the lower IL-rich phase, GVL was produced with quantitative yield and enriched in the upper methanolrich phase. Pure GVL can be obtained by depressurizing to release CO_2 and evaporation to remove methanol of the upper phase, the lower phase containing IL, catalyst and methanol can be recycled for the next reaction. The strategy may provide a new approach to produce and separate products from IL solvents at mild conditions.

关键词： Separation Ionic liquids Selective hydrogenation Mild condition Subcritical CO2

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Change in Continuous Detonation Wave Propagation Mode from Rotating Detonation to Standing Detonation

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Chinese Physics Letters 2010年第3期27卷 216-219页

作者：邵业涛王健平 State Key Laboratory of Turbulence and Complex System CAPT Department of Mechanics and Aerospace Engineering College of Engineering Peking University Beijing 100871

We perform a three-dimensional numerical simulation based on a one-step chemical reaction model to investigate changes in the mode of H2-Air detonation wave propagation from rotating detonation wave （RDW） mode to standing detonation wave mode. The physical characteristics of an RDW with injection velocity of 500 m/s are analyzed to investigate the physical mechanisms involved. We find that with increasing injection velocity, the detonation wave gradually changes from perpendicular to the head wall to parallel to the head wall. When the injection velocity exceeds the Chapman-Jouguet velocity VCJ （about 1984 m/s）, the detonation wave changes orientation to become perpendicular to the fuel injection direction, and the rotating mode changes accordingly to a standing mode. Finally, the plane detonation characteristic triple-wave structures can be found from the standing mode.

关键词： Fluid dynamics Chemical physics and physical chemistry

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Angstrom science:Exploring aggregates from a new viewpoint

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Green Energy & Environment 2016年第1期1卷 75-78页

作者： Suojiang Zhang Feng Huo Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex SystemInstitute of Process EngineeringChinese Academy of Sciences

A small aggregate is composed of several or tens of molecules or ions, with at least one dimension in the range from a few to dozens of angstroms. Here, we named such aggregate system as Angstrom Aggregates(AA). AA with the specific size in angstrom meter might possess unique structure activity relationship. Unlike molecular level, nano system and the bulk, AA, an aggregate in angstrom scale is firstly proposed,its arrangement in order, electronic effect, surface interaction, confinement effect, is still unclear. However, recently, the structure and activity relationship of such aggregate in angstrom scale has attracted increasing interest in many areas, such as in ionic liquids, aqueous solution,catalytic system, and bio-system. As the physical and chemical propeties of AA strongly depends on its structure, the in situ characterizzation technique combined with theoretical methods should be developed to understand the exact interaction between the component of the clusters, the assembly formations, the special features, and the reaction activities. It has great scientific meaning to detect, represent and regulate the structure and function of AA precisely, facilitating in its application. A systematic and thorough research on AA in angstrom scale will promote the development of fundamental science and the progress of technology significantly.

关键词： Angstom science Aggregates Aqueous system Bio-system Ionic liquids

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simulation of dynamic fluid-solid interactions with an improved direct-forcing immersed boundary method

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Particuology 2015年第1期13卷 22-34页

作者： Shengbin Di Wei Ge State Key Laboratory of Multiphase Complex System Institute of Process EngineeringChinese Academy of Sciences University of Chinese Academy of Sciences

Dynamic fluid-solid interactions are widely found in chemical engineering, such as in particle-laden flows, which usually contain complex moving boundaries. The immersed boundary method （IBM） is a convenient approach to handle fluid-solid interactions with complex geometries. In this work, Uhlmann＇s direct-forcing IBM is improved and implemented on a supercomputer with CPU-GPU hybrid architec- ture. The direct-forcing IBM is modified as follows： the Poisson＇s equation for pressure is solved before evaluation of the body force, and the force is only distributed to the Cartesian grids inside the immersed boundary. A multidirect forcing scheme is used to evaluate the body force. These modifications result in a divergence-free flow field in the fluid domain and the no-slip boundary condition at the immersed boundary simultaneously. This method is implemented in an explicit finite-difference fractional-step scheme, and validated by 2D simulations of lid-driven cavity flow, Couette flow between two concentric cylinders and flow over a circular cylinder. Finally, the method is used to simulate the sedimentation of two circular particles in a channel. The results agree very well with previous experimental and numerical data, and are more accurate than the conventional direct-forcing method, especially in the vicinity of a moving boundary.

关键词： Immersed boundary method Fluid-solid interactions No-slip condition Divergence-free condition CPU-GPU hybrid architecture

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Analysis of overload-based cascading failure in multilayer spatial networks

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Chinese Physics B 2020年第9期29卷 404-414页

作者： Min Zhang Xiao-Juan Wang Lei Ji Mei Song Zhong-Hua Liao School of Science Beijing University of Posts and TelecommunicationsBeijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Complex Product Advanced Manufacturing Engineering Research Center Beijing Simulation CenterBeijing 100854China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System EngineeringBeijing 100854China

Many complex networks in real life are embedded in space and most infrastructure networks are interdependent,such as the power system and the transport *** this paper,we construct two cascading failure models on the multilayer spatial *** our research,the distance l between nodes within the layer obeys the exponential distribution P(l)~exp(-l/ζ),and the length r of dependency link between layers is defined according to node *** entropy approach is applied to analyze the spatial network structure and reflect the difference degree between *** metrics,namely dynamic network size and dynamic network entropy,are proposed to evaluate the spatial network robustness and *** the cascading failure process,the spatial network evolution is analyzed,and the numbers of failure nodes caused by different reasons are also counted,***,we discuss the factors affecting network *** demonstrate that the larger the values of average degree,the stronger the network *** the length r decreases,the network performs *** the probability p is small,asζdecreases,the network robustness becomes more *** p is large,the network robustness manifests better performance asζ*** results provide insight into enhancing the robustness,maintaining the stability,and adjusting the difference degree between nodes of the embedded spatiality systems.

关键词： cascading failure multilayer network load distribution spatial network entropy

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A New Recursive Composite Adaptive Controller for Robot Manipulators

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Space(Science & Technology) 2021年第1期2021卷 77-83页

作者： Jianfei Li Yaobing Wang Zhiyong Liu Xin Jing Chengwei Hu The State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China Beijing Key Laboratory of Intelligent Space Robotic System Technology and Applications Beijing Institute of Spacecraft System EngineeringBeijing 100094China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

In this paper,a new recursive implementation of composite adaptive control for robot manipulators is *** investigate the recursive composite adaptive algorithm and prove the stability directly based on the Newton-Euler equations in matrix form,which,to our knowledge,is the first result on this point in the *** proposed algorithm has an amount of computation O(n),which is less than any existing similar algorithms and can satisfy the computation need of the complicated multidegree *** manipulator of the Chinese Space Station is employed as a simulation example,and the results verify the effectiveness of this proposed recursive algorithm.

关键词： Robot manipulators robot

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Regulation of tree water use by biophysical factors: Insights based on multi-layer hierarchical residual analysis

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Journal of Hydrology 2025年 660卷

作者： Du, Jiali Oren, Ram Hölttä, Teemu Feng, Shaoyuan Wang, Weishu Dai, Xiaoqin Huo, Zailin Key Laboratory of Tree Breeding and Cultivation National Forestry and Grassland Administration Research Institute of Forestry Chinese Academy of Forestry Beijing100091 China State Key Laboratory of Efficient Utilization of Agricultural Water Resources China Agricultural University Beijing100083 China Henan Xiaolangdi Forest Ecosystem Observation and Research Station Henan Jiyuan454650 China Nicholas School of the Environment & Pratt School of Engineering Duke University DurhamNC27708 United States Department of Forest Sciences Institute for Atmospheric and Earth System Research INAR/Forest Sciences University of Helsinki FI-00014 Finland College of Hydraulic Science and Engineering Yangzhou University Yangzhou225009 China Qianyanzhou Ecological Research Station Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China

The complex impact of biophysical factors on tree water use in changing environments has been an important topic in the ecohydrological studies. However, understanding how to model tree water use based on key biophysical factors requires an in-depth analysis. This study monitored the sap flow (Q) of Populus popularis in an arid area over four consecutive growing seasons from 2018 to 2021, and leaf area index (LAI), soil water content at 0–30 cm soil depth (SWC0–30 cm), groundwater level, and meteorological variables (photosynthetically active radiation (PAR), solar radiation, air temperature, relative humidity, wind speed at 2 m height, and rainfall). Based on a three-layer hierarchical residual analysis, three novel statistical models representing the total effects of biophysical factors (meteorological variables, water supply conditions, and circadian rhythms factors) on normalized daily sap flow (Q/LAI), normalized nocturnal sap flow (Qn/LAI), and the ratio of nocturnal sap flow to daily sap flow (Qn/Q) were constructed on a daily scale, respectively. These models could estimate Q/LAI, Qn/LAI, and Qn/Q over four years. The results further indicated that daily total PAR and mean SWC0–30 cm best explained the variation in Q/LAI, while nighttime length and mean SWC0–30 cm jointly influenced Qn/LAI. Interannually, the seasonal patterns of daily Q/LAI and Qn/LAI were correlated to the mean growing season SWC0–30 cm. The proposed models can quantify daily tree water use, nighttime water use, and its proportion in daily tree water use using biophysical factors, specifically daily total PAR, SWC0–30 cm, nighttime length, Q, and day of year. Our findings contribute to a deeper understanding of the drivers of daily and nighttime tree water use in arid regions. © 2025 Elsevier B.V.

关键词： Radiation damage

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