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Full lifetime demonstration of a Micro-Cathode-Arc thruster evolution characteristics

Chinese Journal of Aeronautics 2024年第6期37卷 38-49页

作者： Zhe ZHANG Zijing ZHAO xiangyang LIU Ningfei WANG School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Ground lifetime test is the most crucial experiment to assess the performance,*** flight qualification of electric propulsion,and it can bring new insights for understanding the operation *** work demonstrates a full lifetime test of 140000 cycles on a Micro-Cathode-Arc Thruster(μCAT)with 160μs charging time and 86 mJ charging energy.A four-probe resistivity measurement method is utilized to investigate variations in the conductive film thickness and resistivity throughout the thruster *** film parameters show that the lifetime of theμCAT can be divided into three *** the initial stage,the film thickness decreases by 1.2μm and the resistivity increases significantly due to the high discharge intensity and intense film ablation;In the steady stage,the change of the film thickness is within 5%,and the resistivity of the film increases slowly from 0.050Ω·mm to 0.223Ω·*** the end stage,the resistivity exponentially increases from 0.223Ω·mm to 1.176Ω·mm,with the increase accounting for 81%,ultimately resulting in the failure of the thruster open ***,the evolution of discharge parameters,and the variation of plume parameters are measured throughout the *** discharge characteristics also show significant differences in the duration of voltage and current in these three *** results of plume shape and plasma parameters are also we.l con-sistent with the discharge parameters and film *** results suggest that,for evaluating the steady stage lifetime of thrusters,the film thickness is the best indicator compared to the variations in resistivity and voltage-current *** the end stage,the plasma plume *** duration,and plume parameters can conveniently and clearly characterize the thruster failures and irregularity.

关键词： Electric propulsion Lifetime test Micro-Cathode-Arc Thruster(uCAT) Conductive film Discharge characteristics Plasma parameters

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The multiple roles of crop structural change in productivity,nutrition and environment in China:A decomposition analysis

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Journal of Integrative Agriculture 2024年第5期23卷 1763-1773页

作者： xiangyang Zhang Yumei Zhang Shenggen Fan College of Economics and Management China Agricultural UniversityBejing 100083China Academy of Global Food Economics and Policy China Agricultural UniversityBejing 100083China

China's crop structure has undergone significant changes in the last two decades since 2000,with an increase in the share of cereals,vegetables,and fruit,squeezing out other *** a result,land productivity,nutrient supply,and carbon emissions have *** to reallocate limited farmland among crops to achieve the multiple goals of agrifood systems becomes an important *** study explores the sources of land productivity and nutrition supply growth and carbon emissions reduction,and identifies the multiple roles of crop structural change from 2003 to 2020 based on a decomposition *** results reveal that the growth within crops is still the primary driver in land productivity and nutrition supply and the reduction in carbon ***,structural change also plays various roles at different *** 2003 to 2010,crop structural change increased the total calorie supply but lowe.ed land productivity and contributed at least 70%of the total growth of carbon *** crop structure was relatively stable,and their effects we.e modest from 2010 to *** 2015 to 2020,the crop structural change began to play a greater role and generate synergistic effects in improving land productivity,micronutrient supply,and reducing carbon emissions,contributing to approximately a quarter of the growth of land productivity and 30%of total carbon emissions *** results suggest that strategies for crop structural change should comprehensively consider its multiple impacts,aiming to achieve co-benefits while minimizing trade-offs.

关键词： crop structural change land productivity nutrition carbon emissions

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An anonymous authentication and secure data transmission scheme for the Internet of Things based on blockchain

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Frontiers of Computer Science 2024年第3期18卷 183-197页

作者： Xingxing CHEN Qingfeng CHENG we.dong YANG xiangyang LUO State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou Institute of Information Science and TechnologyZhengzhou 450001China Henan Key Laboratory of Grain Photoelectric Detection and Control Henan University of TechnologyZhengzhou 450001China Henan Province Key Laboratory of Cyberspace Situation Awareness Zhengzhou Institute of Information Science and TechnologyZhengzhou 450001China

With the widespread use of network infrastructures such as 5G and low-powe. wide-area networks,a large number of the Internet of Things(IoT)device nodes are connected to the network,generating massive amounts of ***,it is a great challenge to achieve anonymous authentication of IoT nodes and secure data *** present,blockchain technology is widely used in authentication and s data storage due to its decentralization and ***,Fan et *** a secure and efficient blockchain-based IoT authentication and data sharing *** studied it as one of the state-of-the-art protocols and found that this scheme does not consider the resistance to ephemeral secret compromise attacks and the anonymity of IoT *** overcome these security flaws,this paper proposes an enhanced authentication and data transmission scheme,which is verified by formal security proofs and informal security ***,Scyther is applied to prove the security of the proposed ***,it is demonstrated that the proposed scheme achieves better performance in terms of communication and computational cost compared to other related schemes.

关键词： Internet of Things blockchain authentication data transmission

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SPATULA as a Versatile Tool in Plant:The Progress and Perspectives of SPATULA(SPT)Transcriptional Factor

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Phyton-International Journal of Experimental Botany 2024年第3期93卷 517-531页

作者： Lei Liang xiangyang Hu Shanghai Key Laboratory of Bio-Energy Crops Research Center for Natural ProductsPlant Science CenterSchool of Life SciencesShanghai UniversityShanghai200444China

With the rapid development of modern molecular biology and bioinformatics,many studies have proved that transcription factors play an important role in regulating the growth and development of ***(SPT)belongs to the bHLH transcription family and participates in many processes of regulating plant growth and *** review systemically summarizes the multiple roles of SPT in plant growth,development,and stress response,including seed germination,ﬂowe.ing,leaf size,carpel development,and root elongation,which is helpful for us to better understand the functions of SPT.

关键词： SPT bHLH plant growth plant development Arabidopsis thaliana

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Integrating Neighborhood Geographic Distribution and Social Structure Influence for Social Media User Geolocation

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2513-2532页

作者： Meng Zhang xiangyang Luo Ningbo Huang Key Laboratory of Cyberspace Situation Awareness of Henan Province Zhengzhou450001China State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou450001China

Geolocating social media users aims to discover the real geographical locations of users from their publicly available data,which can support online location-based applications such as disaster alerts and local content *** relationship-based methods represent a classical approach for geolocating social ***,geographically proximate relationships are sparse and challenging to discern within social networks,thereby affecting the accuracy of user *** address this challenge,we.propose user geolocation methods that integrate neighborhood geographical distribution and social structure influence(NGSI)to improve geolocation ***,we.propose a method for evaluating the homophily of locations based on the k-order neighbor-hood geographic distribution(k-NGD)similarity among *** are notable differences in the distribution of k-NGD similarity betwe.n location-proximate and non-location-proximate *** this distinction,we.filter out non-location-proximate social relationships to enhance location homophily in the social *** better utilize the location-proximate relationships in social networks,we.propose a graph neural network algorithm based on the social structure *** algorithm enables us to perform a we.ghted aggregation of the information of users’multi-hop neighborhood,thereby mitigating the over-smoothing problem of user features and improving user geolocation *** results on real social media dataset demonstrate that the neighborhood geographical distribution similarity metric can effectively filter out non-location-proximate social ***,compared with 7 existing social relationship-based user positioning methods,our proposed method can achieve multi-granularity user geolocation and improve the accuracy by 4.84%to 13.28%.

关键词： User geolocation social media neighborhood geographic distribution structure influence

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RNase P:Beyond Precursor tRNA Processing

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Genomics, Proteomics & Bioinformatics 2024年第1期22卷 19-28页

作者： Peipei Wang Juntao Lin xiangyang Zheng Xingzhi Xu Guangdong Key Laboratory for Genome Stability&Disease Prevention and Marshall Laboratory of Biomedical Engineering Shenzhen University Medical SchoolShenzhen UniversityShenzhen 518060China Department of Urology The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310000China Shenzhen University General Hospital-Dehua Hospital Joint Research Center on Precision Medicine Dehua HospitalDehua 362500China

Ribonuclease P(RNase P)was first described in the 1970’s as an endoribonuclease acting in the maturation of precursor transfer RNAs(tRNAs).More recent studies,howe.er,have uncovered non-canonical roles for RNase P and its ***,we.review the recent progress of its involvement in chromatin assembly,DNA damage response,and maintenance of genome stability with implications in *** possibility of RNase P as a therapeutic target in cancer is also discussed.

关键词： RNase P Chromatin assembly DNA damage response Genome stability Tumorigenesis

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IP-Pealing: A Robust Network Flow Watermarking Method Based on IP Packet Sequence

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Chinese Journal of Electronics 2024年第3期33卷 694-707页

作者： Wangxin FENG xiangyang LUO Tengyao LI Chunfang YANG State Key Laboratory of Mathematical Engineering and Advanced Computing Key Laboratory of Cyberspace Situation Awareness of Henan Province

Network flow watermarking(NFW) is usually used for flow *** actively modulating some features of the carrier traffic,NFW can establish the correspondence betwe.n different network *** the face of strict demands of network traffic tracing,current watermarking methods cannot work efficiently due to the dependence on specific protocols,demand for large quantities of packets,we.kness on resisting network channel interferences and so *** this end,we.propose a robust network flow watermarking method based on IP packet sequence,called as *** is designed to utilize the packet sequence as watermark carrier with IP identification field which is insensitive to time jitter and suitable for all IP based *** enhance the robustness against packet loss and packet reordering,the detection sequence set is constructed in terms of the variation range of packet sequence,correcting the possible errors caused by the network *** improve the detection accuracy,the long watermark information is divided into several short sequences to embed in turn and assembled during *** a large number of experiments on the Internet,the overall detection rate and accuracy of IP-Pealing reach 99.91% and 99.42%*** comparison with the classical network flow watermarking methods,such as PROFW,IBW,ICBW,WBIPD and SBTT,the accuracy of IP-Pealing is increased by 13.70% to 54.00%.

关键词： Protocols Packet loss Watermarking Telecommunication traffic Jitter Robustness Internet

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Enhancing the activity and succinyl-CoA specificity of 3-ketoacyl-CoA thiolase Tfu_0875 through rational binding pocket engineering

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Synthetic and Systems Biotechnology 2024年第3期9卷 558-568页

作者： Lixia Liu Shuang Liu xiangyang Hu Shenghu Zhou Yu Deng National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing Jiangnan University1800 Lihu RoadWuxiJiangsu214122China Jiangsu Provincial Research Center for Bioactive Product Processing Technology Jiangnan University1800 Lihu RoadWuxiJiangsu214122China

The 3-ketoacyl-CoA thiolase is the rate-limiting enzyme for linear dicarboxylic acids ***,the promiscuous substrate specificity and suboptimal catalytic performance have restricted its *** we.present both biochemical and structural analyses of a high-efficiency 3-ketoacyl-CoA thiolase Tfu_***,Tfu_0875 displayed heightened activity and substrate specificity for succinyl-CoA,a key precursor in adipic acid *** enhance its performance,a deep learning approach(DLKcat)was employed to identify effective mutants,and a computational strategy,known as the greedy accumulated strategy for protein engineering(GRAPE),was used to accumulate these effective *** the mutants,Tfu_0875N249W/L163H/E217L exhibited the highest specific activity(320%of wild-type Tfu_0875),the greatest catalytic efficiency(kcat/KM=1.00 min-1mM-1),the highest succinyl-CoA specificity(KM=0.59 mM,28.1%of Tfu_0875)and dramatically reduced substrate binding energy(-30.25 kcal mol^(-1)v.s.-15.94 kcal mol^(-1)).A structural comparison betwe.n Tfu_0875N249W/L163H/E217L and the wild type Tfu_0875 revealed that the increased interaction betwe.n the enzyme and succinyl-CoA was the primary reason for the enhanced enzyme *** interaction facilitated rapid substrate anchoring and ***,a reduced binding pocket volume improved substrate specificity by enhancing the complementarity betwe.n the binding pocket and the substrate in stereo ***,our rationally designed mutant,Tfu_0875N249W/L163H/E217L,increased the adipic acid titer by 1.35-fold compared to the wild type Tfu_0875 in shake *** demonstrated enzymatic methods provide a promising enzyme variant for the adipic acid *** above effective substrate binding pocket engineering strategy can be beneficial for the production of other industrially competitive biobased chemicals when be applied to other thiolases.

关键词： Adipic acid 3-Ketoacyl-CoA thiolase Claisen condensation Deep learning GRAPE strategy

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Retaining the self-released chalcogenate at reconstructed cobalt sites by self-transformed carbonate regulation for boosted oxygen evolution

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Journal of Energy Chemistry 2024年第10期97卷 46-54,I0002页

作者： Jingxuan Zhao Zhe Xue Qing Wang xiangyang Li Shoujie Liu Xu Zhao School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'an 710049ShaanxiChina Key Laboratoryof Materials Physics Instituteof Solid State PhysicsHefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesHefei 23031 Anhui China School of Materials Science and Engineering Anhui UniversityHefei 230601AnhuiChina

The in-situ generated oxyanions at electrochemically reconstructed catalysts from metal-based nonoxide compounds have been proven to significantly accelerate oxygen evolution reaction(OER)***,it remains a challenge to retain these self-released oxyanions at reconstructed catalysts,hindering its utilization as a tool to develop efficient OER ***,we.demonstrate a versatile selftransformed carbonate regulation strategy to efficiently retain the self-released chalcogenate at Co oxyhydroxides reconstructed from carbon-incorporated Co selenides under OER *** selftransformed CO_(3)^(2-)can induce electron accumulation and narrow d bond at Co sites to facilitate the Co3d-O 2p orbital hybridization betwe.n Co sites and SeO_(x)^(2-)for enhanced SeO_(x)^(2-)retention,which can accelerate the rate-limiting step for^(*)OOH formation during *** to CoOOH-SeO_(x)^(2-)with limited SeO_(x)^(2-)residues,CoOOH-CO_(3)^(2-)/SeO_(x)^(2-)with elevated SeO_(x)^(2-)retention by CO_(3)^(2-)regulation exhibited a 5.6-fold increase in current density and a remarkable lowe. Tafel slope towards *** strategy paves a rational avenue to design efficient catalysts for electrooxidation reactions through finely regulating self-released oxyanions at reconstructed structures.

关键词： Electrochemical reconstruction Chalcogenate retention Carbonate regulation Orbital hybridization Oxygen evolution reaction

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Overhead-free Noise-tolerant Federated Learning: A New Baseline

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Machine Intelligence Research 2024年第3期21卷 526-537页

作者： Shiyi Lin Deming Zhai Feilong Zhang Junjun Jiang Xianming Liu xiangyang Ji Department of Computer Science and Technology Harbin Institute of TechnologyHarbin150000China Department of Automation Tsinghua UniversityBeijing100084China

Federated learning (FL) is a promising decentralized machine learning approach that enables multiple distributed clients to train a model jointly while keeping their data private. Howe.er, in real-world scenarios, the supervised training data stored in local clients inevitably suffer from imperfect annotations, resulting in subjective, inconsistent and biased labels. These noisy labels can harm the collaborative aggregation process of FL by inducing inconsistent decision boundaries. Unfortunately, few attempts have been made towards noise-tolerant federated learning, with most of them relying on the strategy of transmitting overhead messages to assist noisy labels detection and correction, which increases the communication burden as we.l as privacy risks. In this paper, we.propose a simple yet effective method for noise-tolerant FL based on the we.l-established co-training framework. Our method leverages the inherent discrepancy in the learning ability of the local and global models in FL, which can be regarded as two complementary views. By iteratively exchanging samples with their high confident predictions, the two models “teach each other” to suppress the influence of noisy labels. The proposed scheme enjoys the benefit of overhead cost-free and can serve as a robust and efficient baseline for noise-tolerant federated learning. Experimental results demonstrate that our method outperforms existing approaches, highlighting the superiority of our method.

关键词： Federated learning noise-label learning privacy-preserving machine learning edge intelligence distributed machine learning

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