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Performance study of vertical MSM solar-blind photodetectorsbased onβ-Ga_(2)O_(3)thin film

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 17-27页

作者： che. haifeng che.Lujie Lu Qin Wang Shaoqing Liu Xiangtai Liu Zhanhang Guan Youyou Zhao Xu che.g Hang Han Xiaocong Zhang Xuhui School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

In this work,β-Ga_(2)O_(3)thin films were grown on SiO_(2)substrate by atomic layer deposition(ALD)and annealed in N_(2)atmosphere to enhance the crystallization quality of the thin films,which were verified from X-rays diffraction(XRD).Based on the grownβ-Ga_(2)O_(3)thin films,vertical metal-semiconductor-metal(MSM)interdigital photodetectors(PDs)were fabricated and *** PDs have an ultralow dark current of 1.92 pA,ultra-high photo-to-dark current ratio(PDCR)of 1.7×10^(6),and ultra-high detectivity of 4.25×10^(14)Jones at a bias voltage of 10 V under 254 nm deep ultraviolet(DUV).Compared with the horizontal MSM PDs under the same process,the PDCR and detectivity of the fabricated vertical PDs are increased by 1000 times and 100 times,*** addition,the vertical PDs possess a high responsivity of 34.24 A/W and an external quantum efficiency of 1.67×10^(4)%,and also exhibit robustness and repeatability,which indicate excellent *** the effects of electrode size and external irradiation conditions on the performance of the vertical PDs continued to be investigated.

关键词： Ga_(2)O_(3) atomic layer deposition(ALD) annealing vertical metal-semiconductor-metal(MSM)interdigital photodetectors

Dual metal ions/BNQDs boost PMS activation over copper tungstate photocatalyst for antibiotic removal:Intermediate,toxicity assessment and mechanism

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Journal of Materials Science & Technology 2024年第3期170卷 11-24页

作者： Ruyao che. Haiyue Zhang Yuming Dong haifeng Shi School of Science Jiangnan UniversityWuxi214122China The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationJiangnan UniversityWuxi214122China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China

In the metal-based peroxymonosulfate(PMS)activation process,the sluggish surface redox cycle of metal ions generally hampered the efficiency of PMS activation for pollutant ***,Codoped CuWO 4/BN quantum dots(CW/Co/BNQDs)photocatalysts were developed to realize Cu^(2+)/Cu+and Co^(2+)/Co^(3+)dual ions redox cycles for PMS activation,which would facilitate the tetracycline(TC)***/4Co/2BNQDs could degrade 94.8%TC within 30 min in PMS/Vis system,and the apparent rate constant of CW/4Co/2BNQDs was 2.7 times and 1.2 times higher than those of CW and CW/4Co,*** improved TC degradation performance could be attributed to the synergetic effect between BNQDs and dual redox cycles.X-ray photoelectron spectroscopy(XPS)spectra of samples before and after the reaction demonstrated that BNQDs were beneficial for accelerating the Cu^(2+)/Cu+and Co^(2+)/Co^(3+)redox cycles in CW/4Co/2BNQDs,further boosting the activation of PMS in TC *** of different radical scavengers revealed that the SO_(4)^(·−)/·OH/h+/^(1)O_(2)reactive species participated in the PMS activation for the TC degradation *** possible TC degradation pathway and intermediate toxicity were detailed *** addition,CW/4Co/2BNQDs exhibited outstanding photocatalytic activity over five consecutive cycles,which illustrated that it was supposed to be a reliable PMS activator over antibiotic elimination for practical *** this work shed new light on constructing dual redox cycles for efficient PMS activation.

关键词： Dual redox cycles Photocatalysis Peroxymonosulfate BN quantum dots Toxicity assessment

Asymmetric Hydrogenation of Phenanthridines with Chiral Boranes

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Chinese Journal of che.istry 2024年第6期42卷 631-635页

作者： Guangyu Cui Xiangqing Feng haifeng Du Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionInstitute of ChemistryChinese Academy of SciencesBeijing100190 China University of Chinese Academy of Sciences Beijing100049 China

The asymmetric hydrogenation of N-heteroarenes provides an efficient method for the synthesis of optically active cyclic secondary *** this paper,we described an asymmetric hydrogenation of phenanthridines using a chiral mono-alkene-derived borane.A variety of dihydrophenanthridines were furnished in high yields with up to 93%*** current catalytic system was very sensitive for the steric hindrance of *** substituents at one phenyl group of phenanthridines were required to obtain the high *** large substituents on the carbon of the C=N bonds would diminish the reactivity sharply.

关键词： Asymmetric catalysis Hydrogenation Nitrogen heterocycles Phenanthridines Frustrated Lewis pairs Chiral boranes

Precision design of Ti sites for unprecedented catalytic performance

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National Science Review 2024年第7期11卷 67-68页

作者： Haoquan Zheng Shunai che Key Laboratory of Applied Surface and Colloid che.istry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University School of che.istry and che.ical Engineering Shanghai Jiao Tong University

In 1983, Taramasso et al. incorporated titanium(Ti) into porous silica frameworks to endow Ti sites with catalytic oxidation ability [1]. Nowadays, catalytic oxidation reactions using titanium silicate materials have ...

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Reducing idleness in financial cloud services via multi-objective evolutionary reinforcement learning based load balancer

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Science China(Information Sciences) 2024年第2期67卷 20-40页

作者： Peng YANG Laoming ZHANG haifeng LIU Guiying LI Department of Statistics and Data Science Southern University of Science and Technology Guangdong Provincial Key Laboratory of Brain-Inspired Intelligent Computation Department of Computer Science and EngineeringSouthern University of Science and Technology Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology Guangdong OPPO Mobile Telecommunications Corp. Ltd Research Institute of Trustworthy Autonomous Systems Southern University of Science and Technology

In recent years, various companies have started to shift their data services from traditional data centers to the cloud. One of the major motivations is to save on operational costs with the aid of cloud elasticity. This paper discusses an emerging need from financial services to reduce the incidence of idle servers retaining very few user connections, without disconnecting them from the server side. This paper considers this need as a bi-objective online load balancing problem. A neural network based scalable policy is designed to route user requests to varied numbers of servers for the required elasticity. An evolutionary multi-objective training framework is proposed to optimize the weights of the policy. Not only is the new objective of idleness reduced by over 130% more than traditional industrial solutions, but the original load balancing objective itself is also slightly improved. Extensive simulations with both synthetic and real-world data help reveal the detailed applicability of the proposed method to the emergent problem of reducing idleness in financial services.

关键词： evolutionary reinforcement learning evolutionary multi-objective optimization load balance cloud computing

Asymmetric Partial Hydrosilylation of 2,2-Difluoro-1,3-diketones with Chiral Frustrated Lewis Pairs

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Chinese Journal of che.istry 2024年第8期42卷 853-857页

作者： Ting Liu Xiangqing Feng haifeng Du Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionInstitute of ChemistryChinese Academy of SciencesBeijing100190 China University of Chinese Academy of Sciences Beijing100049 China

Comprehensive Summary,The asymmetric partial reduction of 1,3-diketones stands as a straightforward pathway to access optically active β-hydroxyketones. In this paper, an asymmetric Piers-type hydrosilylation of 2,2-difluoro-1,3-diketones was successfully realized by using a frustrated Lewis pair of chiral borane and tricyclohexylphosphine as a catalyst, delivering a variety of α,α-difluoro-β-hydroxyketones in high yields with up to 99% ee. Significantly, no over-reduced diol products were observed even with an excess amount of silanes. The product can be conveniently converted to α,α-difluoro-β-hydroxyester or 1,3-anti-diol via an oxidation with m-CPBA or a reduction with DIBAL-H without obvious loss of ee.

关键词： Asymmetric catalysis Hydrosilylation Ketones Frustrated Lewis pairs Chiral boranes

Multi-level intelligence empowering lithium-ion batteries

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Journal of Energy che.istry 2024年第10期97卷 535-552,I0011页

作者： Guangxu Zhang Jiangong Zhu haifeng Dai Xuezhe Wei School of Materials Science and Engineering Tongji UniversityShanghai 201804China School of Automotive Studies Tongji UniversityShanghai 201804China

With the significant and widespread application of lithium-ion batteries,there is a growing demand for improved performances of lithium-ion *** intricate degradation throughout the whole lifecycle profoundly impacts the safety,durability,and reliability of lithium-ion *** ensure the long-term,safe,and efficient operation of lithium-ion batteries in various fields,there is a pressing need for enhanced battery intelligence that can withstand extreme *** work reviews the current status of intelligent battery technology from three perspectives:intelligent response,intelligent sensing,and intelligent *** intelligent response of battery materials forms the foundation for battery stability,the intelligent sensing of multi-dimensional signals is essential for battery management,and the intelligent management ensures the long-term stable operation of lithium-ion *** critical challenges encountered in the development of intelligent battery technology from each perspective are thoroughly analyzed,and potential solutions are proposed,aiming to facilitate the rapid development of intelligent battery technologies.

关键词： Battery intelligence Intelligent response Intelligent sensing Intelligent management

Data and Model Driven Task Offloading Strategy in the Dynamic Mobile Edge Computing System

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Journal of Systems Science & Complexity 2024年第1期37卷 351-368页

作者： DONG Hairong WU Wei SONG haifeng LIU Zhen ZHANG Zixuan School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China School of Electronic and Information Engineering BeiHang UniversityBeijing 100191China CRSC Research&Design Institute Group Co. Ltd.Beijing 100070China

Mobile Edge Computing(MEC)provides communication and computational capabilities for the industrial Internet,meeting the demands of latency-sensitive ***,traditional model-driven task offloading strategies face challenges in adapting to situations with unknown network communication status and computational *** limitation becomes notably significant in complex industrial networks of high-speed *** by these considerations,a data and model-driven task offloading problem is proposed in this paper.A redundant communication network is designed to adapt to anomalous channel states when tasks are offloaded to edge *** link switching mechanism is executed by the train according to the attributes of the completed *** task offloading optimization problem is formulated by introducing data-driven prediction of communication states into the traditional ***,the optimal strategy is achieved by employing the informer-based prediction algorithm and the quantum particle swarm optimization method,which effectively tackle real-time optimization problems due to their low time *** simulations illustrate that the data and model-driven task offloading strategy can predict the communication state in advance,thus reducing the cost of the system and improving its robustness.

关键词： Data driven model informer mobile edge computing quantum particle swarm optimization task offloading.

Review of Three-phase Soft Switching Inverters and Challenges for Motor Drives

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CES Transactions on Electrical Machines and Systems 2024年第2期8卷 177-190页

作者： haifeng Lu Qiao Wang Jianyun Chai Yongdong Li IEEE the Department of Electrical Engineering Tsinghua UniversityBeijing 100084China the School of Electrical Engineering Xinjiang UniversityUrumqi 830047China

For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the *** exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging speed and power ***,this trend poses significant challenges for high-voltage and high-frequency motor controllers,which are plagued by increased switching losses and pronounced switching oscillations as consequences of hard *** deployment of soft switching technology presents a viable solution to mitigate these *** paper reviews the applications of soft switching technologies for three-phase inverters and classifies them based on distinct *** each type of inverter,the advantages and disadvantages are ***,the paper introduces the research progress and control methods of soft switching inverters (SSIs).Moreover,it presents a comparative analysis among the conventional hard switching inverters (HSIs),an active clamping resonant DC link inverter (ACRDCLI) and an auxiliary resonant commuted pole inverter (ARCPI).Finally,the problems and prospects of soft switching technology applied to motor controllers for EVs are put forward.

关键词： Soft switching inverters Zero-voltage switching Electric vehicles Motor drives