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Conversion of savanna rangelands to bush dominated landscape in Borana,Southern Ethiopia

Ecological Processes 2016年第1期5卷 60-77页

作者： Teshome Abate Ayana Angassa School of Animal and Range Sciences Hawassa UniversityHawasaEthiopia

Introduction:Analyzing trends of land use systems and the changes occurred overtime is an effective way of assessing the impacts of land use/land cover(LULC)changes on ecosystem *** provides important insights for understanding the spatial patterns of land use *** rangelands of southern Ethiopia are adversely affected by increased human population pressure,encroachment of crop cultivation,and bush ***,it is vital to understand the trends of rangeland vegetation cover ***:This paper evaluates land use/land cover changes and spatial patterns between 1987 and 2003 in Yabelo(5426 km2),Borena rangelands of southern *** used a combination of three Landsat Thematic Mapper(TM)1987,Landsat TM 1995 and Enhanced Thematic Mapper Plus(ETM+)2003,and local perceptions.A pixelbased supervised classification with maximum likelihood classifier was used to classify *** accuracy of classification was assessed for 1987(81.8%),1995(84.6%),and 2003(81.3%).Results:The results showed that the Borana rangelands had undergone substantial changes during the last 16 *** 1987 and 2003,we observed a considerable increase in woodland cover(11.7%),bushland cover(17%),cultivated land(72.5%),and settlements(79.8%).The results showed a rapid decline in grassland cover(7.7%),shrubby grassland cover(86%),and bareland(0.7%).The spatial pattern analysis indicate that the Borana rangeland was fragmented and characterized by the proliferation of large numbers of patches with a decline in patch index,increased patch density,and irregular shape of patches within a *** communities’perceptions indicate that recurrent drought,increased human population size,and expansion of cultivation were largely responsible for the observed LULC changes in the study ***:LULC changes contribute to rangeland degradation and weaken the traditional practices of rangeland *** suggest appropriate management measures to halt the

关键词： Bush encroachment Landscapepattern Remotesensing LULC Boranarangeland

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Channel pruning on frequency response

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Science China(Information Sciences) 2025年第1期68卷 159-170页

作者： Hang LIN Yifan PENG Lin BIE Chenggang YAN Xibin ZHAO Yue GAO School of Software Tsinghua University School of Automation Hangzhou Dianzi University

Network pruning has a significant role in reducing network parameters and accelerating the inference time of the network. Some existing methods prune the network based on the frequency of the data, and finally obtain a sub-network with high accuracy. However, according to our experimental analysis, different frequencies of information in the data contribute differently to the accuracy of the model, and using this information directly for pruning without making a selection will lead to incorrect results. We believe that pruning should retain the convolutional kernels in the network that process important information, while those kernels that process unimportant information should be removed. In this paper, we first investigate the meaning of each frequency band information in the spectrum and their contribution to the prediction accuracy of the network,and according to these results, we propose a new pruning method based on frequency response(PFR). Our PFR finds and removes the convolutional kernels in the network that specialize in processing unimportant information, resulting in a compact neural network model. PFR obtains significant experimental results on different datasets, for example, a 56.0% raduction of float points operations(FLOPs) on Res Net-50 and only 0.37% of Top-1 accuracy degradation on the Image Net dataset.

关键词： deep learning model compression filter pruning channel pruning frequency response

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Personalized federated few-shot node classification

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Science China(Information Sciences) 2025年第1期68卷 204-218页

作者： Yunfeng ZHAO Xintong HE Guoxian YU Jun WANG Yongqing ZHENG Carlotta DOMENICONI School of Software Shandong University Joint SDU-NTU Centre for Artificial Intelligence Research Shandong University Department of Mathematics National University of Singapore Department of Computer Science George Mason University

Personalized federated learning(PFL) aims to train customized models for individual clients in a decentralized setting, with the account of non-independent and identically distributed data across clients. However, most PFL methods adopt uniform classification layers for diverse clients and give rise to error-prone predictions, due to the task heterogeneity notably prominent in decentralized graph data scenarios. Although some PFL solutions setup client-specific classification layers for each client and optimize them only locally, they are corrupted with limited local training data. We propose an innovative solution called federated parameter decoupling and node augmentation(Fed PANo) to address these problems and to achieve personalized federated few-shot node classification, which is a prevalent and challenging but unexplored topic. Specifically, Fed PANo first separates the local model into the GNN and classifier to handle unique client-specific task variations. The GNN is trained through federated learning to capture shared knowledge of graph nodes across clients, while the classifier is custom-designed and trained individually for each client. Additionally, a generic classifier shared among clients is adopted to encourage the GNN's grasp of shared information. Then Fed PANo further proposes the node generator along with its local and collaborative training strategies to deal with the node scarcity of clients. Extensive experimental results on benchmark datasets confirm that Fed PANo outperforms eight competitive baselines across different settings.

关键词： personalized federated learning few-shot learning node classification task heterogeneity parameter decoupling node augmentation

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Self-assembly of two pairs of homochiral M2L4 coordination capsules with varied confined space using Tr?ger's base ligands

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Chinese Chemical Letters 2025年第2期36卷 360-365页

作者： Yi Zhou Wei Zhang Rong Fu Jiaxin Dong Yuxuan Liu Zihang Song Han Han Kang Cai College of Chemistry Nankai University Department of Chemistry Northwestern University Department of Chemistry The University of Hong Kong

Chiral coordination molecular cages/capsules with discrete nanoconfined chiral cavities demonstrate significant potential applications across various fields. In this study, we utilized Tr?ger's base as the building block to design and synthesize two pairs of enantiopure ligands. These ligands were then self-assembled with Pd(II) ions through chiral self-sorting coordination, resulting in the formation of two pairs of homochiral M2L4-type coordination molecular capsules. Notably, due to differences in the substitution positions on the Tr?ger's base, these two pairs of enantiomeric coordination molecular capsules exhibited distinct levels of cavity closures, cavity sizes, and host-guest recognition properties. This research offers valuable insights into the construction of novel chiral molecular capsules and the regulation of confined cavities.

关键词： Chirality Host-guest recognition Metal-organic capsule Self-sorting Tröger's base

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Aperiodically semi-intermittent-based fixed-time stabilization and synchronization of delayed discontinuous inertial neural networks

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Science China(Information Sciences) 2025年第1期68卷 238-254页

作者： Guodong ZHANG Jinde CAO School of Mathematics and Statistics South-Central Minzu University School of Mathematics Southeast University

This article concentrates on the fixed-time stabilization(FS) and fixed-time synchronization(FTS) of discontinuous inertial neural networks(DINNs) with distributed delays. Using mathematical induction to a new differential equality, a novel fixed-time stability lemma is constructed. Then, by designing an aperiodically semi-intermittent switching control and combining it with the theory of nonsmooth analysis, some novel criteria on the FS and FTS of DINNs are obtained. Unlike the methods used in most existing studies, the FS and FTS results are structured using the newly proposed fixed-time stability lemma and the nonreduced-order approach, resulting in broader practical applications and strengthening the scientific quality of the derived results. Lastly, numerical simulations and applications proffer the effectiveness of the established FS and FTS criteria.

关键词： inertial neural networks fixed-time synchronization semi-intermittent switching control nonreduced-order approach fixed-time stabilization

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Pressure-Dependent Thermal Network Model for Press-Pack Power Modules with Prognostics of Mechanical Status

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CSEE Journal of Power and Energy Systems 2025年第1期11卷 424-439页

作者： Yao Chang Yu Zhou Ankang Zhu Haoze Luo Wuhua Li Chushan Li Francesco Iannuzzo Xiangning He College of Electrical Engineering Zhejiang UniversityHangzhou310027China Zhejiang university–university of Illinois at Urbana-Champaign Institute Zhejiang UniversityHaining314400China Department of Energy Technology Aalborg UniversityAalborg 9220Denmark

The press-pack power module with multi-chip layout has drawn increasing attention from industry and academia with its thermal analysis becoming an essential ***,the pressure-dependent thermal variables,such as thermal contact resistance and thermal coupling resistance,are often *** this paper,a pressure-dependent thermal network model is developed to characterize the thermal performance and mechanical status of press-pack power *** including the thermal contact resistance and thermal coupling resistance as the function of pressure,the proposed model ensures a more precise thermo-mechanical evaluation inside the press-pack power *** influence of pressure on self-heating effects and thermal coupling effects of power modules is studied using the knowledge of elastic mechanics.A press-pack prototype with variable pressure loads is ***,thermal experiments under different pressures on chips are conducted and the pressure-variable temperature responses of the thermal network are ***,the feasibility of the proposed thermal network model is validated.A cost-effective prognostic method on the mechanical status of press-pack power module is also achieved.

关键词： Mechanical status press-pack power module pressure-dependent model thermal network.

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Electronic interactions between neighboring functionalized guest Sb single atoms and Pt clusters enhance CO tolerance

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Journal of Energy Chemistry 2025年第2期101卷 733-743页

作者： Wenkang Miao Ronghui Hao Lu Gan Wanyin Xu Zihan Wang Wenxin Lin Heguang Liu Yinchun Lyu Qianqian Li Jinyang Xi Anmin Nie Jinsong Wu Hongtao Wang Materials Genome Institute Shanghai University School of Materials Science and Engineering Zhejiang Sci-Tech University School of Materials Science and Engineering Xi'an University of Technology Center for High Pressure Science State Key Laboratory of Metastable Materials Science and Technology Yanshan University Nanostructure Research Center Wuhan University of Technology Center for X-mechanics Zhejiang University

Platinum-based（Pt） catalysts are notoriously susceptible to deactivation in industrial chemical processes due to carbon monoxide（CO） *** this poisoning deactivation of Pt-based catalysts while enhancing their catalytic activity,selectivity,and durability remains a major ***,we propose a strategy to enhance the CO tolerance of Pt clusters（Pt_n） by introducing neighboring functionalized guest single atoms（such as Fe,Co,Ni,Cu,Sb,and Bi）.Among them,antimony（Sb） single atoms（SAs） exhibit significant performance enhancement,achieving 99% CO selectivity and 33.6% CO2conversion at 450℃,Experimental results and density functional theory（DFT） calculations indicate the optimization arises from the electronic interaction between neighboring functionalized Sb SAs and Pt clusters,leading to optimal 5d electron redistribution in Pt clusters compared to other functionalized guest single *** redistribution of 5d electrons weaken both the σ donation and π backdonation interactions,resulting in a weakened bond strength with CO and enhancing catalyst activity and *** situ environmental transmission electron microscopy（ETEM） further demonstrates the exception thermal stability of the catalyst,even under H2at 700℃.Notably,the functionalized Sb SAs also improve CO tolerance in various heterogenous catalysts,including Co/CeO2,Ni/CeO2,Pt/Al2O3,and Pt/*** finding provides an effective approach to overcome the primary challenge of CO poisoning in Pt-based catalysts,making their broader applications in various industrial catalysts.

关键词： CO tolerance Electronic effect Functionalized guest single atoms In-situ TEM Pt cluster

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Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN T.ASGHAR Z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： analytical solution Cattaneo-Christov heat and mass flux chemical reaction gyrotactic microorganism hybrid nanofluid O368 oscillating curved stretchable sheet

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Identifiability and sloppiness of structured systems with a matrix fraction description using finite frequency responses

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Science China(Information Sciences) 2025年第2期68卷 200-215页

作者： Yunxiang MA Tong ZHOU Department of Automation Tsinghua University Department of Automation and BNRist Tsinghua University

This paper investigates the identifiability of structured systems with a matrix fraction description and attacks practical difficulties in estimating parameters under finite frequency responses. The numerator and denominator polynomial matrices depend affinely on system parameters, which can represent a broad range of systems, especially circuits and mechanical systems. Except for assuming that the denominator matrix is invertible, no further assumptions are adopted. A criterion is provided for validating this assumption utilizing graph theories and matroids. A sufficient and necessary criterion for global identifiability based on the rank of a numerical matrix is given and can be recursively verified with each frequency point,which is computationally attractive for large-scale systems. For an identifiable system, an ellipsoid approximation is obtained for the set of parameters whose corresponding system frequency responses deviate within a specific range from those of the system at a specific parameter value. Using this approximation, explicit expressions for absolute and relative sloppiness have been derived, which can be used to quantify the difficulty of identifying system parameters. Comparisons with the well-known Fisher information matrix have also been performed through a mechanical system, revealing significant differences in quantifying parameter estimation hardness.

关键词： identifiability sloppiness structured system matrix fraction graph theory matroid

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Upcycling of monomers derived from waste polyester plastics via electrocatalysis

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Journal of Energy Chemistry 2025年第2期101卷 535-561页

作者： Haoye Wang Richard Lee Smith Jr Xinhua Qi College of Environmental Science and Engineering Nankai University Graduate School of Environmental Studies Tohoku University

Electrocatalysis offers efficient and targeted conversion of monomers derived from waste polyester plastics to chemical products under ambient temperature and pressure *** review provides analysis of research on electrochemical upgrading of monomers derived from waste polyester plastics published from2021 to *** for assessing upgrading of waste polyester plastics include alkaline hydrolysis pretreatment,indices of electrochemical reaction process(activity,stability,and techno-economic a nalysis),separation,and product *** of depolymerization monomers and their value-added products are summarized along with electrocatalytic mechanisms and reaction ***,cathode coupled reactions offer significant value for anodic waste plastic oxidation during electrolysis *** of bifunctional electrocatalysts can reduce the cost of coupled systems and complexity of the *** and recycling of waste plastic monomers using electrocatalytic technology should undergo downstream processing to form high-value products containing C-N and C-S derived functional groups obtained from depolymerized monomers,Electrochemical conversion and upgrading of monomers derived from waste polyester plastics can contribute to industrialization and global economies and help to realize environmental sustainability.

关键词： Coupling reaction Electrocatalysis Monomer Upgrade recycling Value-added products Waste plastics

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