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Low-Complexity Reconstruction of Covariance Matrix in Hybrid Uniform Circular Array

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China Communications 2024年第3期21卷 66-74页

作者： Fu Zihao Liu Yinsheng Duan hongtao Information School Communication University of ChinaBeijing 100024China Beijing Institute of Electronic System Engineering Beijing 100854China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China Beijing Radio Monitoring Station of State Radio Monitoring Center(SRMC) Beijing 100037China

Spatial covariance matrix(SCM) is essential in many multi-antenna systems such as massive multiple-input multiple-output(MIMO). For multi-antenna systems operating at millimeter-wave bands, hybrid analog-digital structure has been widely adopted to reduce the cost of radio frequency *** this situation, signals received at the antennas are unavailable to the digital receiver, and as a consequence, traditional sample average approach cannot be used for SCM reconstruction in hybrid multi-antenna systems. To address this issue, beam sweeping algorithm(BSA) which can reconstruct the SCM effectively for a hybrid uniform linear array, has been proposed in our previous works. However, direct extension of BSA to a hybrid uniform circular array(UCA)will result in a huge computational burden. To this end, a low-complexity approach is proposed in this paper. By exploiting the symmetry features of SCM for the UCA, the number of unknowns can be reduced significantly and thus the complexity of reconstruction can be saved accordingly. Furthermore, an insightful analysis is also presented in this paper, showing that the reduction of the number of unknowns can also improve the accuracy of the reconstructed SCM. Simulation results are also shown to demonstrate the proposed approach.

关键词： hybrid array millimeter-wave spatial covariance matrix uniform circular array

Plant photobiology: From basic theoretical research to crop production improvement

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Journal of Integrative Plant Biology 2024年第5期66卷 847-848页

作者： hongtao Liu Jigang Li College of Life Sciences and Oceanography Shenzhen UniversityShenzhen 518061China State Key Laboratory of Plant Environmental Resilience College of Biological SciencesChina Agricultural UniversityBeijing 100193China

As one of the most important environmental signals for plants,light plays a profound role in regulating virtually every aspect of plant growth and *** signals are perceived by plants via several families of photoreceptors,among which phytochromes are responsible for absorbing the red(R)and far-red(FR)wavelengths(600–750 nm),cryptochromes(CRYs)perceive the blue(B)/ultraviolet-A(UV-A)wavelengths(32.–500 nm),and UV RESISTANCE LOCUS 8(UVR8)is a recently-characterized UV-B(2.0–32. nm)photoreceptor.

关键词： UVR8 photoreceptor development

Surface morphologies of Mg-Gd alloy particle during its reactions with O_(2. and Teflon

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Defence Technology（防务技术） 2024年第3期33卷 209-221页

作者： Yifan Li hongtao Yang Aifeng Jiang Dongming Song Yanchun Li Department of Chemical Engineering Nanjing University of Science and TechnologyNanjing 210097China Xi'an Modern Chemistry Research Institute Xi'an 710065China Southwest Technology and Engineering Research Institute Chongqing 400039China

Mg-Gd alloy particle has exhibited its unique combustion properties as the fuel of Mg/Teflon/Viton(MTV).Mg-Gd alloy/Teflon/Viton(MGTV)could burn at lower ambient pressure than *** further investigate the reaction of MGTV in air,it was investigated via thermo gravity-differential scanning calorimetry(TG-DSC).Meanwhile,the morphologies and element distributions on the alloy surface during the reaction of MGTV in air were investigated via scanning electronic microscope-mapping-electronic differential ***,a similar experimental protocol on the Mg-Gd alloy particle during oxidation was also *** results showed that owning to a protective oxide shell,the onset oxidation temperature of Mg-Gd alloy is higher than ***,the onset oxidation temperature of the exceeded Mg-Gd alloy in MGTV is significantly lower than that of the exceeded Mg in *** was due to the existence of GdOF,which could significantly lower the oxidation temperature of the exceeded ***,a possible reaction mechanism was *** fascinating oxidation properties of Mg-Gd alloy suggested its promising applications in energetic materials.

关键词： Mg-Gd alloy Energetic materials Morphology EDS GdOF

Design of low-alloying and high-performance solid solution-strengthened copper alloys with element substitution for sustainable development

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 826-832页

作者： Jiaqiang Li hongtao Zhang Jingtai Sun Huadong Fu Jianxin Xie Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory for Advanced Materials Processing(MOE) University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing 100083China Liaoning Academy of Materials Shenyang 110004China

Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other *** the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper *** the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this *** new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and *** total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 62.MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state *** dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332.and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties.

关键词： element substitution copper alloy solid solution strengthening microstructure and performance

A learning-based control pipeline for generic motor skills for quadruped robots

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 443-454页

作者： Yecheng SHAO Yongbin JIN Zhilong HUANG hongtao WANG Wei YANG Center for X-Mechanics Zhejiang UniversityHangzhou310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Hangzhou311200China State Key Laboratory of Fluid Power&Mechatronic Systems Zhejiang UniversityHangzhou310058China Institute of Applied Mechanics Zhejiang UniversityHangzhou310027China

Performing diverse motor skills with a universal controller has been a longstanding challenge for legged *** motion imitation-based reinforcement learning(RL)has shown remarkable performance in reproducing designed motor skills,the trained controller is only suitable for one specific type of *** synthesis has been well developed to generate a variety of different motions for character animation,but those motions only contain kinematic information and cannot be used for *** this study,we introduce a control pipeline combining motion synthesis and motion imitation-based RL for generic motor *** design an animation state machine to synthesize motion from various sources and feed the generated kinematic reference trajectory to the RL controller as part of the *** the proposed method,we show that a single policy is able to learn various motor skills ***,we notice the ability of the policy to uncover the correlations lurking behind the reference motions to improve control *** analyze this ability based on the predictability of the reference trajectory and use the quantified measurements to optimize the design of the *** demonstrate the effectiveness of our method,we deploy the trained policy on hardware and,with a single control policy,the quadruped robot can perform various learned skills,including automatic gait transitions,high kick,and forward jump.

关键词： Quadruped robot Reinforcement learning(RL) Motion synthesis Control

Improved Data Stream Clustering Method: Incorporating KD-Tree for Typicality and Eccentricity-Based Approach

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Computers, Materials & Continua 2024年第2期78卷 2557-2573页

作者： Dayu Xu Jiaming Lu Xuyao Zhang hongtao Zhang College of Mathematics and Computer Science Zhejiang A&F UniversityHangzhou311300China College of Economics and Management Zhejiang A&F UniversityHangzhou311300China

Data stream clustering is integral to contemporary big data ***,addressing the ongoing influx of data streams efficiently and accurately remains a primary challenge in current *** paper aims to elevate the efficiency and precision of data stream clustering,leveraging the TEDA(Typicality and Eccentricity Data Analysis)algorithm as a foundation,we introduce improvements by integrating a nearest neighbor search algorithm to enhance both the efficiency and accuracy of the *** original TEDA algorithm,grounded in the concept of“Typicality and Eccentricity Data Analytics”,represents an evolving and recursive method that requires no prior *** the algorithm autonomously creates and merges clusters as new data arrives,its efficiency is significantly hindered by the need to traverse all existing clusters upon the arrival of further *** work presents the NS-TEDA(Neighbor Search Based Typicality and Eccentricity Data Analysis)algorithm by incorporating a KD-Tree(K-Dimensional Tree)algorithm integrated with the Scapegoat *** arrival,this ensures that new data points interact solely with clusters in very close *** significantly enhances algorithm efficiency while preventing a single data point from joining too many clusters and mitigating the merging of clusters with high overlap to some *** apply the NS-TEDA algorithm to several well-known datasets,comparing its performance with other data stream clustering algorithms and the original TEDA *** results demonstrate that the proposed algorithm achieves higher accuracy,and its runtime exhibits almost linear dependence on the volume of data,making it more suitable for large-scale data stream analysis research.

关键词： Data stream clustering TEDA KD-tree scapegoat tree

Regulating the non-effective carriers transport for high-performance lithium metal batteries

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Journal of Energy Chemistry 2024年第5期92卷 132-141页

作者： Simeng Wang Youchun Yu Shaotong Fu hongtao Li Jiajia Huang Institute of Process Engineering Chinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Haike Group Research Institute of Innovation&Technology Dongying 257000ShangdongChina

The absence of control over carriers transport during electrochemical cycling,accompanied by the deterioration of the solid electrolyte interphase(SEI)and the growth of lithium dendrites,has hindered the development of lithium metal ***,a separator complexion consisting of polyacrylonitrile(PAN)nanofiber and MIL-101(Cr)particles prepared by electrospinning is proposed to bind the anions from the electrolyte utilizing abundant effective open metal sites in the MIL-101(Cr)particles to modulate the transport of non-effective *** binding effect of the PANM separator promotes uniform lithium metal deposition and enhances the stability of the SEI layer and long cycling stability of ultra-high nickel layered oxide *** PANM as the Li||NCM96 separator enables high-voltage cycling stability,maintaining 72.capacity retention after 800 cycles at a charging and discharging rate of 0.2.C at a cut-off voltage of 4.5 V and 0°***,the excellent high-rate performance delivers a specific capacity of 156.3 mA h g^(-1) at 10 *** addition,outstanding cycling performance is realized from−2. to 60°*** separator engineering facilitates the electrochemical performance of lithium metal batteries and enlightens a facile and promising strategy to develop fast charge/discharge over a wide range of temperatures.

关键词： Functional separators Metal-organic frameworks 3D continuous ion transport networks Electrospinning Lithium metal batteries

Heteroatom anchors Fe-Mn dual-atom catalysts with bi-functional oxygen catalytic activity for low-temperature rechargeable flexible Zn-air batteries

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Journal of Energy Chemistry 2024年第3期90卷 610-620,I0014页

作者： Yuting He hongtao Li Yi Wang Yufei Jia Yongning Liu Qiang Tan State Key Laboratory for Mechanical Behaviour of Materials School of Materials Science&EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina

M-N-C(M=Fe,Co,Ni,etc.) catalyst owns high catalytic activity in the oxygen catalytic reaction which is the most likely to replace the Pt-based *** it is still a challenge to further increase the active site *** article constructs the high-efficiency FeMn-N/S-C-1000 catalyst to realize ORR/OER bifunctional catalysis by hetero-atom,bimetal(Fe,Mn) doped simultaneously *** evaluated it as bi-functional electro-catalysts,FeMn-N/S-C-1000 exhibits excellent catalytic activity(E_(1/2.=0.92. V,E_(j=10)=1.617 V) in alkaline media,outperforms conventional Pt/C,RuO_(2. and most non-precious-metal catalysts reported recently,Such outstanding performance is owing to N,S co-coordinated with metal to form multi-types of single atom,dual atom active sites to carry out ***,nitrite poison test provides the proof that the active sites of FeMn-N/S-C are more than that of single-atom catalysts to promote catalytic reactions *** better understand the local structure of Fe and Mn active sites,XAS and DFT were employed to reveal that FeMn-N_5/S-C site plays the key role during ***,the FeMn-N/S-C-1000 based low-temperature rechargeable flexible Zn-air also exhibits superior discharge performance and extraordinary durability at-40℃.This work will provide a new idea to design diatomic catalysts applied in low-temperature rechargeable batteries.

关键词： Fe Mn-N/S-C-1000 ORR OER Rechargeable flexible Zn-air batteries

Neiguan(PC6) acupoint stimulation for preventing chemotherapy-induced nausea and vomiting: a cost-effective supplement in guideline-inconsistent chemotherapy-induced nausea and vomiting prophylaxis subgroup

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Journal of Traditional Chinese Medicine 2024年第3期44卷 581-585页

作者： YU Wenxi TANG Lina LI hongtao WANG Yonggang SHEN Zan Department of Oncology Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai200233China

OBJECTIVE: To assess the efficacy and safety of Neiguan(PC6) acupoint acustimulation in preventing chemotherapy-induced nausea and vomiting(CINV),especially for patients with guideline-inconsistent CINV prophylaxis(GICP) due to personal reasons METHODS: From January 2.2. to December 2.2., 373 patients suffered from solid malignancy were recruited according to the inclusion criteria. Complete response(no emesis and no rescue medication use) rate during the overall phase(0-12. h of each chemo-cycle) was the primary assessment of CINV control. The Functional Living Index-Emesis(FLIE) questionnaire was investigated among these patients as a secondary 'quality of life' objective to assess the impact of CINV on patients' daily life by recording score of nausea and vomiting. RESULTS: With acustimulation of Neiguan(PC6) acupuncture point through a portable, noninvasive and user-friendly device, in terms of complete response rate and scores in nausea/vomiting by FLIE questionnaire, patients achieve a better outcome in highly emetogenic chemotherapy(HEC) induced CINV, especially GICP subgroup. Meanwhile, analysis also demonstrated this tendency existed in other patients with HEC/GCCP(guideline consistent CINV prophylaxis) and moderate emetogenic chemotherapy, although the difference was not significant. CONCLUSION: Considering advantages of Neiguan(PC6) acustimulation such as noninvasive, covered by medical insurance and few side effects, we believe it would be an ideal auxiliary tool in CINV control, especially in patients who receive highly emetogenic chemoprotocol and are reluctant to GCCP for economic reasons.

关键词： acupuncture acustimulation tumor chemotherapy-induced nausea and vomiting