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Intelligent reflecting surfaces-assisted millimeter wave communication:Channel estimation based on deep learning

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 49-56页

作者： Kang Xiaofei Wang tian liang xian College of Communication and Information Engineering Xi'an University of Science and TechnologyXi'an 710600China

In response to the challenge posed by the complexity of the system and the difficulty in obtaining accurate channel state information(CSI)for millimeter wave communication assisted by intelligent reflecting surfaces(IRS),we propose a deep learning-based channel estimation *** proposed scheme employs a hybrid active/passive IRS architecture,wherein the least square(LS)algorithm is initially utilized to acquire the channel estimate from the active ***,this estimation is interpolated to obtain a preliminary channel estimation and ultimately refined into an accurate estimate of the channel using the channel super-resolution convolutional neural network(Chan-SRCNN)deep learning *** simulation results demonstrate that the proposed scheme surpasses LS,orthogonal matching pursuit(OMP),synchronous OMP(SOMP),and deep neural network(DNN)channel estimation algorithms in terms of normalized mean squared error(NMSE)performance,thereby validating the feasibility of the proposed approach.

关键词： intelligent reflecting surface millimeter wave channel estimation deep learning

Plants affect the horizontal transmission of a new densovirus infecting the green peach aphid Myzus persicae by modulating honeydew production

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Insect Science 2024年第1期31卷 236-254页

作者： Ya Guo Yani Zhao Yang Yang Yahong Zhang Yuying li Honggang tian Tong-xian liu Zhaofei li State Key Laboratory of Crop Stress Biology for Arid Areas Key Laboratory of Northwest Loess Plateau Crop Pest Management of Ministry of AgricultureCollege of Plant ProtectionNorthwest A&F UniversityYanglingChina Institute of Entomology and Institute of Plant Health&Medicine Guizhou UniversityGuiyangChina

In a tritrophic context of plant-insect-entomopathogen,plants play important roles in modulating the interaction of insects and their pathogenic ***,the influence of plants on the transmission of insect viruses has been mainly studied on baculoviruses and some RNA viruses,whereas the impact of plants on other insect viruses is largely ***,we identified a new densovirus infecting the green peach aphid Myzus persicae and tested whether and how host plants influence the transmission of the aphid *** complete single-stranded DNA genome of the virus,*** densovirus 2,is 5727 nt and contains inverted terminal *** and phylogenetic analysis indicated that the virus was distinct from other a few identified aphid *** virus abundance was detected highly in the intestinal tract of aphids,compared with the lower level of it in other tissues including head,embryo,and *** and pepper plants had no obvious effect on the vertical transmission and saliva-mediated horizontal transmission of the ***,the honeydew-mediated horizontal transmission among aphids highly depended on host plants(65%on cabbages versus 17%on peppers).Although the virus concentration in the honeydew produced by aphids between 2 plants was similar,the honeydew production of the infected aphids reared on peppers was dramatically *** together,our results provide evidence that plants influence the horizontal transmission of a new densovirus in an aphid population by modulating honeydew secretion of aphids,suggesting plants may manipulate the spread of an aphid-pathogenic densovirus in nature.

关键词： aphids densovirus host plants MpDV2 Myzus persicae transmission

Interpretation and characterization of rate of penetration intelligent prediction model

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Petroleum Science 2024年第1期21卷 582-596页

作者： Zhi-Jun Pei xian-Zhi Song Hai-Tao Wang Yi-Qi Shi Shou-Ceng tian Gen-Sheng li College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Petroleum Resources and Prospecting Beijing102249China Kunlun Digital Technology Co. Ltd.Beijing102206China

Accurate prediction of the rate of penetration(ROP)is significant for drilling *** the intelligent ROP prediction model based on fully connected neural networks(FNN)outperforms traditional ROP equations and machine learning algorithms,its lack of interpretability undermines its *** study proposes a novel interpretation and characterization method for the FNN ROP prediction model using the Rectified linear Unit(ReLU)activation *** leveraging the derivative of the ReLU function,the FNN function calculation process is transformed into vector *** FNN model is linearly characterized through further simplification,enabling its interpretation and *** proposed method is applied in ROP prediction scenarios using drilling data from three vertical wells in the Tarim *** results demonstrate that the FNN ROP prediction model with ReLU as the activation function performs exceptionally *** relative activation frequency curve of hidden layer neurons aids in analyzing the overfitting of the FNN ROP model and determining drilling data *** the well sections with similar drilling data,averaging the weight parameters enables linear characterization of the FNN ROP prediction model,leading to the establishment of a corresponding linear representation ***,the quantitative analysis of each feature's influence on ROP facilitates the proposal of drilling parameter optimization schemes for the current well *** established linear characterization equation exhibits high precision,strong stability,and adaptability through the application and validation across multiple well sections.

关键词： Fully connected neural network Explainable artificial intelligence Rate of penetration ReLU active function Deep learning Machine learning

Theoretical Design of Defects as a Driving Force for Ion Transport in li_(3)OBr Solid Electrolyte

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Energy & Environmental Materials 2024年第3期7卷 143-153页

作者： Xingyun Luo Yanlu li xian Zhao State Key Lab of Crystal Materials and Institute of Crystal Materials Shandong UniversityJinan 250100China Center for Optics Research and Engineering Shandong UniversityQingdao 266237China

Due to ever-increasing concerns about safety issues in using li ionic batteries,solid electrolytes have extensively *** li-rich antiperovskite li_(3)OBr has been considered as a promising solid electrolyte candidate,but it still suffers challenges to achieve a high ionic conductivity owing to the high intrinsic symmetry of the crystal ***,we presented a design strategy that introduces various point defects and grain boundaries to break the high lattice symmetry of li_(3)OBr crystal,and their effect and microscopic mechanism of promoting the migration of li-ion were explored *** has been found that li_(i)are the dominant defects responsible for the fast li-ion diffusion in bulk li_(3)OBr and its surface,but they are easily trapped by the grain boundaries,leading to the annihilating of the Frenkel defect pair V'_(li)+li_(i),and thus limits the V'_(li)diffusion at the grain *** V_(Br)defect near the grain boundaries can effectively drive V'_(li)across the grain boundary,thereby converting the carrier of li^(+)migration from li,in the bulk and surface to V'_(li)at the grain boundary,and thus improving the ionic conductivity in the whole li_(3)OBr *** work provides a comprehensive insight into the li^(+)transport and conduction mechanism in the li_(3)OBr *** opens a new way of improving the conductivity for all-solid-state li electrolyte material through the defect design.

关键词： defects density functional theory ionic migration solid electrolyte

Metal-organic nanosheet assembly ions sieving membrane for precise lithium ion and anion/solvent separation toward robust lithium metal battery

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Science China Chemistry 2024年第10期67卷 3320-3327页

作者： Jian-Qiang Shen tian-tian Zhao Ying-li Song lingjuan Zhang Ya-Nan Gao Xiao-Nan Cui Peng Zhao xian-Ming Zhang Key Laboratory of Magnetic Molecules&Magnetic Information Materials Ministry of EducationSchool of Chemistry&Material ScienceShanxi Normal UniversityTaiyuan 030031China College of Chemistry and Chemical Engineering Taiyuan University of TechnologyTaiyuan 030024China

Metal-organic nanosheets(MONs)as a novel material with tunable pore structures and low mass transfer resistance,have emerged as molecular sieves for the separation of gases and *** theory,they can also serve as ion sieves for lithium metal batteries(LMBs),realizing the high-energy and dendritic free ***,there are rarely relevant reports,because it is difficult to simultaneously balance efficient ion sieving ability,high ion passing rate and high electrochemical ***,we synthesized a stable ultrathin MON[Zn_(2)(Bim)_(4)]([Zn_(2)(Bim)_(4)]Nanosheet,HBim=benzimidazolate),which can achieve both efficient lithium ion sieving ability,high lithium ion passing rate and high electrochemical stability at the same *** separator assembled by this MON exhibits high li^(+)transfer number of 0.81 due to the accurate lithium ion and anion/solvent *** battery containing such separator shows high lithium ionic conductivity of 0.74 m S cm^(-1)and low activation energy of 0.099 eV,which can be attributed to the nanometer level thickness and the ion sieving *** is more,we realized the application of MONs-based ion sieves in LMBs with intercalation cathodes for the first *** the liFePO_(4)|li battery with as-assembled separator demonstrates improved Coulombic efficiency(>99%)and significantly extended cycling life(>1600 cycles)with 80%capacity retention.

关键词： lithium sieving membrane metal-organic nanosheets lithium metal battery lithium ion and anion separation lithium ion and solvent separation

Rational Engineering of Secondary Metabolic Pathways in a Heterologous Host to Enable the Biosynthesis of Hibarimicin Derivatives with Enhanced Anti-Melanomic Activity

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Engineering 2024年第7期38卷 113-123页

作者： xiangyang liu Fei-Peng Zhao tian tian Wei-Chen Wang Zaizhou liu Qiang Zhou xian-Feng Hou Jing Wang Wenli Guo Shuangjun lin Yasuhiro Igarashi Gong-li Tang State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China State Key Laboratory of Microbial Metabolism&Joint International Research Laboratory on Metabolic and Developmental Sciences School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China Biotechnology Research Center Toyama Prefectural UniversityImizu 939-0398Japan

A 61-kb biosynthetic gene cluster(BGC),which is accountable for the biosynthesis of hibarimicin(HBM)B from Microbispora rosea *** TP-A0121,was heterologously expressed in Streptomyces coelicolor M1154,which generated a trace of the target products but accumulated a large amount of shunt *** on rational analysis of the relevant secondary metabolism,directed engineering of the biosynthetic pathways resulted in the high production of HBM B,as well as new HBM derivates with improved antitumor *** results not only establish a biosynthetic system to effectively synthesize HBMs-a class of the largest and most complex Type-Ⅱpolyketides,with a unique pseudo-dimeric structure-but also set the stage for further engineering and deep investigation of this complex biosynthetic pathway toward potent anticancer drugs.

关键词： Hibarimicin Biosynthesis Heterologous expression Biosynthetic gene cluster Rational engineering Type-II polyketide

Design and high-power testing of offline conditioning cavity for CiADS RFQ high-power coupler

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Nuclear Science and Techniques 2024年第9期35卷 18-27页

作者： Ruo-Xu Wang Yuan He Long-Bo Shi Chen-Xing li Zong-Heng Xue tian-Cai Jiang xian-Bo Xu lie-Peng Sun Zhou-li Zhang Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Lanzhou University Lanzhou 730000China

To validate the design rationality of the power coupler for the RFQ cavity and minimize cavity contamination,we designed a low-loss offline conditioning cavity and conducted high-power *** offline cavity features two coupling ports and two tuners,operating at a frequency of 162.5 MHz with a tuning range of 3.2 *** the installation angle of the coupling ring and the insertion depth of the tuner helps minimize cavity *** performed electromagnetic structural and multiphysics simulations,revealing a minimal theoretical power loss of 4.3%.However,when the cavity frequency varied by110 kHz,theoretical power losses increased to10%,necessitating constant tuner adjustments during *** simulations indicated that increased cavity temperature did not affect frequency *** completion of the offline high-power conditioning platform,we measured the transmission performance,revealing a power loss of 6.3%,exceeding the theoretical *** utilized efficient automatic range scanning and standing wave resonant *** fully condition the power coupler,a 15°phase difference between two standing wave points in the condition-ing system was ***,the maximum continuous wave power surpassed 20 kW,exceeding the expected target.

关键词： RFQ cavity Power coupler Offline conditioning Resonant cavity

Evaluation of transmission risk of respiratory particles under different ventilation strategies in an elevator

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Building Simulation 2024年第5期17卷 771-784页

作者： liangyu Zhu xian li Bujin Feng Fan liu School of Civil Engineering and Architecture Linyi UniversityLinyi276000China College of Agriculture Shandong Agricultural UniversityTaian271018China School of Environment and Architecture University of Shanghai for Science and TechnologyShanghai200093China

People in elevators are at risk of respiratory infection because the elevator cabin is crowded and has poor *** exhaled particles may be inhaled by the susceptible person,deposited on the surface and suspended in the elevator,which can result in direct and indirect ***,whether the air vent designs adopted in the elevator can effectively reduce the transmission risk of respiratory particles remains *** this study,the dispersion of particles under four common ventilation strategies used in the commercial elevator was investigated by proven computational fluid dynamics(CFD)*** flow field was simulated with the RNG κ-ξ turbulence model and the Lagrangian method was adopted to track particle *** effects of air vent layout and airflow rate on particle transmission were *** found that more than 50% of exhaled particles(average value)were suspended in the cabin and difficult to discharge under the investigated ventilation *** deposited fraction of particles on the susceptible person reached up to 39.14% for infiltration ventilation,which led to a high risk of contact *** the ventilation rate could not significantly reduce the inhalation proportion of particles due to the poor airflow distribution inside the elevator.A more proper ventilation strategy should be explored for the elevator to control transmission risk.

关键词： particle dispersion transmission risk elevator ventilation strategy computational fluid dynamics(CFD)

The origins of catalytic selectivity for the electrochemical conversion of carbon dioxide to methanol

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Nano Research 2024年第1期17卷 5-17页

作者： tian Wang Yating Wang Yuhang li Chunzhong li Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai 200237China School of Chemical Engineering East China University of Science&TechnologyShanghai 200237China

The electrocatalytic conversion of carbon dioxide(CO_(2))into useful fuels and chemical feedstocks is an emerging route to alleviate global warming and reduce reliance on fossil ***(CH_(3)OH),as one of the most significant and widely used liquid fuels that can be generated by CO_(2)reduction,is essential in the chemical *** this minireview,we unravel the origins of the selective formation of CH_(3)OH via CO_(2)reduction,including catalyst composition designs,local structure modulations,and electrolyte/catalyst interface ***,the remaining challenges and perspectives for the CO_(2)-to-CH_(3)OH reduction are proposed.

关键词： methanol carbon dioxide(CO_(2))reduction reaction electrochemistry electrocatalyst catalyst-electrolyte interface