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Energy and AI 2024年第1期15卷 236-247页

作者： Andre Adam Huazhen fang Xianglin Li Department of Mechanical Engineering University of Kansas1530 W 15th St.Lawrence66045KSUSA Department of Mechanical Engineering and Materials Science Washington University in St.LouisOne Brookings DriveSt.Louis63130MOUSA

Topology optimization of heterogeneous structures can find significant use in a wide range of applications,and its fabrication has been made possible by recent advances in additive ***,the optimization procedure is computationally expensive,as each structural update requires the re-evaluation of the *** computational time is the major limiting factor in large-scale and complex structural *** this study,a convolutional neural network(CNN)model for predicting effective thermal conductivity inspired by the VGG networks is *** using 130,000 unique binary images,the model achieves high predictive ***,it shows a mean absolute percent error(MAPE)of 0.35%in testing when the thermal conductivity of the solid is ten times larger than the fluid,and when the thermal conductivities assigned are that of aluminum and water,the MAPE is 2.35%.The prediction time is 15 ms for a single image with 128×128 pixels,which is 3 to 5 orders of magnitude faster than a finite volume *** employed in topology optimization,the CNN retains a MAPE between 0.67%and 11.8%for different *** CNN model correctly predicts trends in effective thermal conductivity and improves the structure to close proximity of a theoretical maximum in all cases.

关键词： Machine learning Effective thermal conductivity Convolutional neural network VGG Numerical heat transfer Topology optimization

Current status and challenges of pig-to-human organ xenotransplantation

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Science China(Life Sciences) 2024年第4期67卷 829-831页

作者： Minghui fang Yong-Guang Yang Zheng Hu Key Laboratory of Organ Regeneration&Transplantation of Ministry of Education and National-Local Joint Engineering Laboratory of Animal Models for Human DiseasesThe First Hospital of Jilin UniversityChangchun 130061China

Organ shortage is a global *** collected by the Global Observatory on Donation and Transplantation reveals that over 150,000 solid organ transplants are conducted globally each year,a 52%increase from 2010(http://***/... 详细信息

关键词： globally global shortage

Unraveling the atomic interdiffusion mechanism of NiFe_(2_)O_(4)oxygen carriers during chemical looping CO_(2)conversion

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Carbon Energy 2024年第8期6卷 105-121页

作者： Da Song Yan Lin Shiwen fang Yang Li Kun Zhao Xinfei Chen Zhen Huang fang He Zengli Zhao Hongyu Huang Fanxing Li Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhouChina School of Energy Science and Engineering University of Science and Technology of ChinaHefeiChina College of Mechanical and Electrical Engineering Zhongkai University of Agriculture and EngineeringGuangzhouChina College of Chemistry and Bioengineering Guilin University of TechnologyGuilinChina North Carolina State University RaleighNorth CarolinaUSA

By employing metal oxides as oxygen carriers,chemical looping demonstrates its effectiveness in transferring oxygen between reduction and oxidation environments to partially oxidize fuels into syngas and convert CO_(2)into ***,NiFe_(2_)O_(4)oxygen carriers have demonstrated remarkable efficiency in chemical looping CO_(2)***,the intricate process of atomic migration and evolution within the internal structure of bimetallic oxygen carriers during continuous high‐temperature redox cycling remains ***,the lack of a fundamental understanding of the complex ionic migration and oxygen transfer associated with energy conversion processes hampers the design of high‐performance oxygen ***,in this study,we employed in situ characterization techniques and theoretical calculations to investigate the ion migration behavior and structural evolution in the bulk of NiFe_(2_)O_(4)oxygen carriers during H2 reduction and CO_(2)/lab air oxidation *** discovered that during the H2 reduction step,lattice oxygen rapidly migrates to vacancy layers to replenish consumed active oxygen species,while Ni leaches from the material and migrates to the *** the CO_(2)splitting step,Ni migrates toward the core of the bimetallic oxygen carrier,forming Fe–Ni *** the air oxidation step,Fe–Ni migrates outward,creating a hollow structure owing to the Kirkendall effect triggered by the swift transfer of lattice *** metal atom migration paths depend on the oxygen transfer *** discoveries highlight the significance of regulating the release–recovery rate of lattice oxygen to uphold the structures and reactivity of oxygen *** work offers a comprehensive understanding of the oxidation/reduction‐driven atomic interdiffusion behavior of bimetallic oxygen carriers.

关键词： chemical looping CO_(2)splitting density functional theory in situ characterization ionic migration

SMA-origami coupling:online configuration switches and stability property modulation

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International Journal of Smart and Nano Materials 2024年第1期15卷 21-41页

作者： Hai Zhou Hongbin fang Zuolin Liu Jian Xu School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghaiChina Institute of AI and Robotics Fudan UniversityShanghaiChina Yiwu Research Institute Fudan UniversityYiwuZhejiangChina

Active folding is a crucial requirement for practical applications of multi-stable origami ***,research on integrating active materials with origami structures to enable quick configuration switching and modulation of stability properties is still in its early *** advance the state-of-the-art,we designed a coupled structure comprising a stacked Miura-origami(SMO)structure and two Shape Memory Alloy(SMA)*** actuator is used for extruding the SMO structure while the other is used for retracting,thereby realizing bidirectional reversible active folding of the coupled *** the potential energy of the coupled structure shows that it can be switched between monostable and bistable by heating the SMA *** above findings are also confirmed by experiments conducted on a delicate SMO-SMA coupled structure *** activation of different actuators induces rapid configuration switching of the coupled structure,and the stability profile is qualitatively adjusted by designing the current loading profile to achieve steady-state temperature ***,this study provides a new approach to coupling origami structures with smart materials for active folding and presents a novel method to regulate the stability property of origami structures,thus promoting their practical applications.

关键词： Multistability bistable origami active folding smart material

Long-wave infrared emission properties of strain-balanced InAs/In_(x)Ga_(1-x)As_(y)Sb_(1-y)type-Ⅱsuperlattice on different substrates

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Rare Metals 2024年第7期43卷 3194-3204页

作者： Chao Shi Xuan fang Hong-Bin Zhao Deng-Kui Wang Xi Chen Dan fang Dong-Bo Wang Xiao-Hua Wang Jin-Hua Li State Key Laboratory of High Power Semiconductor Lasers School of PhysicsChangchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Advanced Materials for Smart Sensing China General Research Institute for Nonferrous MetalsBeijing 100088China Department of Opto-Electronic Information Science School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic *** the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic *** this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates *** grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'***,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more *** addition,the optical properties of superlattices grown on different substrates are discussed *** of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared ***,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.

关键词： Photoluminescence Alloy compositions fluctuations InAs(Sb)/In_(x)Ga_(1-x)As_(y)Sb_(1-y) Type-Ⅱsuperlattice Substrate

Valorization of carbon dioxide with alcohols

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Chinese Chemical Letters 2024年第7期35卷 54-58页

作者： Daheng Wen Weiwei fang Yongmei Liu Tao Tu Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of ChemistryFudan UniversityShanghai 200438China Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsCollege of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Utilizing CO_(2)for the production of bulky and valuable chemicals presents an attractive solution to address environmental and fossil energy *** the various approaches,direct carboxylation of alcohols with CO_(2)stands out as an eco-friendly process capable of efficiently producing carboxylic acids in a sustainable ***,the high dissociation energy of the C–O bond poses a significant challenge in this *** the past few decades,several strategies have been developed to activate alcohols and establish efficient catalytic systems for carboxylation with CO_(2).Nevertheless,the sporadic nature of reported approaches makes it difficult to determine the most effective *** perspective aims to provide an overview of the current state-of-the-art catalytic protocols for carboxylating alcohols with CO_(2),encompassing esterification,halogenation,and photocatalysis,while considering their respective advantages and *** aim to discern the most promising avenues for future development in this *** insights presented in this perspective will contribute to the advancement of efficient and sustainable carboxylation methods using CO_(2),leading to the production of valuable chemicals in future.

关键词： Carboxylation Carbon dioxide Alcohol Carboxylic acid Transition metal catalysis

A Novel Fall Detection Framework Using Skip-DSCGAN Based on Inertial Sensor Data

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Computers, Materials & Continua 2024年第1期78卷 493-514页

作者： Kun fang Julong Pan Lingyi Li Ruihan Xiang College of Information Engineering China Jiliang UniversityHangzhou310018China

With the widespread use of Internet of Things(IoT)technology in daily life and the considerable safety risks of falls for elderly individuals,research on IoT-based fall detection systems has gainedmuch *** paper proposes an IoT-based spatiotemporal data processing framework based on a depthwise separable convolution generative adversarial network using skip-connection(Skip-DSCGAN)for fall *** method uses spatiotemporal data from accelerometers and gyroscopes in inertial sensors as input data.A semisupervised learning approach is adopted to train the model using only activities of daily living(ADL)data,which can avoid data imbalance ***,a quantile-based approach is employed to determine the fall threshold,which makes the fall detection frameworkmore *** proposed fall detection framework is evaluated against four other generative adversarial network(GAN)models with superior anomaly detection performance using two fall public datasets(SisFall&MobiAct).The test results show that the proposed method achieves better results,reaching 96.93% and 92.75% accuracy on the above two test datasets,*** the same time,the proposed method also achieves satisfactory results in terms ofmodel size and inference delay time,making it suitable for deployment on wearable devices with limited *** addition,this paper also compares GAN-based semisupervised learning methods with supervised learning methods commonly used in fall *** clarifies the advantages of GAN-based semisupervised learning methods in fall detection.

关键词： Fall detection skip-connection depthwise separable convolution generative adversarial networks inertial sensor

Imitation Learning Based Real-time Decision-making of Microgrid Economic Dispatch Under Multiple Uncertainties

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1183-1193页

作者： Wei Dong Fan Zhang Meng Li Xiaolun fang Qiang Yang School of Automation Hangzhou Dianzi UniversityHangzhou 310018China College of Electrical Engineering Zhejiang UniversityHangzhou 310027China

The intermittency of renewable energy generation,variability of load demand,and stochasticity of market price bring about direct challenges to optimal energy management of *** cope with these different forms of operation un-certainties,an imitation learning based real-time decision-mak-ing solution for microgrid economic dispatch is *** this solution,the optimal dispatch trajectories obtained by solv-ing the optimal problem using historical deterministic operation patterns are demonstrated as the expert samples for imitation *** improve the generalization performance of imita-tion learning and the expressive ability of uncertain variables,a hybrid model combining the unsupervised and supervised learn-ing is *** denoising autoencoder based unsupervised learning model is adopted to enhance the feature extraction of operation ***,the long short-term memory network based supervised learning model is used to efficiently characterize the mapping between the input space composed of the extracted operation patterns and system state variables and the output space composed of the optimal dispatch *** numerical simulation results demonstrate that under vari-ous operation uncertainties,the operation cost achieved by the proposed solution is close to the minimum theoretical *** with the traditional model predictive control method and basic clone imitation learning method,the operation cost of the proposed solution is reduced by 6.3%and 2.8%,respective-ly,overa test period of three months.

关键词： Energy management imitation learning datadriven decision economic dispatch

Multiple-stage spatial-temporal cooperative guidance without time-to-go estimation

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Chinese Journal of Aeronautics 2024年第9期37卷 399-416页

作者： Chunyan WANG Weilin WANG Wei DONG Jianan WANG fang DENG School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China National Key Lab of Autonomous Intelligent Unmanned Systems Beiing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

This paper investigates the spatial-temporal cooperative guidance problem for multiple flight vehicles without relying on time-to-go ***,a two-stage cooperative guidance strategy,namely the cooperative guidance and the Proportional Navigation Guidance(PNG)stage strategy,is developed to realize the spatial-temporal constraints in two *** the former stage,two controllers are designed and superimposed to satisfy both impact time consensus and impact angle *** the convergent conditions are satisfied,the flight vehicles will switch to the PNG stage to ensure zero miss *** further extend the results to three dimensions,a planar pursuit guidance stage is additionally imposed at the beginning of *** to the inde-pendence of time-to-go estimation,the proposed guidance strategy possesses great performance in satisfying complex spatial-temporal constraints even under flight speed ***,several numerical simulations are implemented to verify the effectiveness and advantages of the proposed results under different scenarios.

关键词： Cooperative guidance Guided missiles Impact time consensus Impact angle constraint Spatial-temporal cooperative guidance

Impact of climate change on food security in the Central Asian countries

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Science China Earth Sciences 2024年第1期67卷 268-280页

作者： fang SU Yu LIU Lvfan CHEN Rustam OROZBAEV Liangcheng TAN School of Economics and Management Northwest UniversityXi’an 710127China School of Economics and Management Shaanxi University of Science and TechnologyXi’an 710021China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China Institute of Geology National Academy of Sciences of Kyrgyz RepublicBishkek 720040Kyrgyzstan Institute of Global Environmental Change Xi’an Jiaotong UniversityXi’an 710049China

The current and potential impacts of global warming have generated widespread concerns about food security among all sectors of *** Asian countries located deep in the interior of Asia with fragile ecological environments and lower agricultural technology are particularly more prone to severe threats from climate *** on panel data acquired in five Central Asian countries from 1990 to 2019,a C-D-C model was developed to study how climate change affects food security in the region and to predict future *** study found that the level of food security has generally increased for these five Central Asian countries over the past 30 years,with Kazakhstan and Tajikistan having the highest and lowest food security levels,*** average annual temperature and precipitation exhibit an inverted U-shaped relationship with the region’s food security,with the most positive effect on the food security of *** high and low temperatures have significantly affected food security in the studied region,with Turkmenistan experiencing the most significant negative *** number of frost days had no significant effect on food *** analysis of future climate showed that the temperature and precipitation in Central Asia will continue to increase from 2030 to 2090,which will negatively impact the food security of these *** is recommended that the Central Asian countries enhance their understanding of climate risks,strengthen scientific climate research,and develop multiple adaptation strategies in ***,they are encouraged to consolidate international cooperation,reducing greenhouse gas emissions effectively and maintaining the ability to ensure food security.

关键词： Global warming Extreme climate Food security Future forecasts Five Central Asian countries