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A feedback control method for phase signal demodulation in fber-optic hydrophones

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 515-528页

作者： Zhiqiang liu lei XIA Qiangfeng LYU Bin WU Ronghua HUAN Zhilong HUANG Department of Mechanics Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang UniversityHangzhou 310000China Huanjiang Laboratory Zhuji 311899Zhejiang ProvinceChina Advanced Technology Research Institute Zhejiang UniversityHangzhou 310000China

In the realm of acoustic signal detection,the identification of weak signals,particularly in the presence of negative signal-to-noise ratios,poses a significant *** challenge is further heightened when signals are acquired through fiber-optic hydrophones,as these signals often lack physical significance and resist clear systematic *** processing methods,e.g.,low-pass filter(LPF),require a thorough understanding of the effective signal bandwidth for noise reduction,and may introduce undesirable time *** paper introduces an innovative feedback control method with dual Kalman filters for the demodulation of phase signals with noises in fiber-optic hydrophones.A mathematical model of the closed-loop system is established to guide the design of the feedback control,aiming to achieve a balance with the input phase *** dual Kalman filters are instrumental in mitigating the effects of signal noise,observation noise,and control execution noise,thereby enabling precise estimation for the input phase *** effectiveness of this feedback control method is demonstrated through examples,showcasing the restoration of low-noise signals,negative signal-to-noise ratio signals,and multi-frequency *** research contributes to the technical advancement of high-performance devices,including fiber-optic hydrophones and phase-locked amplifiers.

关键词： feedback control method fiber-optic hydrophone acoustic signal detection phase signal

Fabrication and characterization of multi-scale coated boron powders with improved combustion performance:A brief review

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Defence Technology（防务技术） 2024年第1期31卷 27-40页

作者： Rui liu Danfeng Yang Kunyu Xiong Ying-lei Wang Qi-Long Yan Science and Technology on Combustion Internal Flow and Thermo-structure LaboratoryNorthwestern Polytechnical UniversityXi'an710072China Xi'an Modern Chemistry Research Institute Xi'an710065China

Boron has high mass and volume calorific values,but it is difficult to ignite and has low combustion *** literature review summarizes the strategies that are used to solve the above-mentioned problems,which include coatings of boron by using fluoride compounds,energetic composites,metal fuels,and metal *** techniques include recrystallization,dual-solvent,phase transfer,electrospinning,*** one of the effective coating agents,the fluorine compounds can react with the oxide shell of boron *** comparison,the energetic composites can effectively improve the flame temperature of boron powder and enhance the evaporation efficiency of oxide film as a condensed *** and metal oxides would react with boron powder to form metal borides with a lower ignition point,which could reduce its ignition temperature.

关键词： Boron powder coating Structure and morphology Condensed phase thermal reaction Ignition and combustion

Dynamical switchable quantum nonreciprocity induced by off-resonant chiral two-photon driving

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 31-37页

作者： Da-Wei liu Zi-Hao Li Shi-lei Chao Ying Wu liu-Gang Si School of Physics and Institute for Quantum Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

Optical nonreciprocity,which refers to the direction-dependent emission,scattering and absorption of photons,plays a very important role in quantum engineering and quantum information ***,we propose an all-optical approach to achieve the optical dynamical switchable quantum nonreciprocity by an off-resonant chiral two-photon driving in a single microring cavity,which differs from the conventional nonreciprocal *** is shown that the optical field with time-dependent statistical properties can be generated and the nonreciprocity flips periodically,with switchable photon blockade and photon-induced tunneling *** find that the dynamical system is robust and immune to the parameter variations,which loosens the parameter range of ***,the time window for one-way quantum information is sufficiently wide and *** work opens a new idea for the current quantum nonreciprocal research,which can facilitate a memory functionality and be used for future inmemory superconducting quantum *** other nonreciprocal quantum devices,i.e.,dynamical switchable nonreciprocal squeezing and entanglement,may be inspired by our method,which is expected to have important applications in future quantum technology.

关键词： dynamical switchable nonreciprocity single-photon source chiral two-photon driving

Solidification/Stabilization of Chromium in Red Mud-based Geopolymer

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 819-830页

作者：田崇霏 LUO Zhongtao liu lei liu Xiaohai 张美香陈萌 HAI Ran School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Henan Renbang Technology Co. Ltd.Luoyang 471700China School of Water Conservancy and Civil Engineering Zhengzhou UniversityZhengzhou 450001China School of Architectural and Civil Engineering Zhongyuan University of TechnologyZhengzhou 450007China

Up to 1.5wt%of Cr(Ⅲ)salts(CrCl_(3),and Cr_(2)O_(3))and Cr(Ⅵ)salts(Na_(2)CrO_(4),and CaCr_(2)O_(7))were incorporated into red mud-based geopolymers,*** solidification/stabilization,compressive strength,and durability of the Cr-containing geopolymers were *** experimental results indicate that the red mud-based geopolymer could effectively solidify/stabilize different types of Cr salts with solidification/stabilization rates of above 99.61%.Geopolymers are environmentally safe when the dosage of CaCr_(2)O_(7)is≤1.0wt%,or the dosage of CrCl_(3),Cr_(2)O_(3),and Na_(2)CrO_(4)is≤1.5wt%,*** effects of Cr salts on the compressive strength varies with the type and content of Cr *** freeze-thaw cycle is more destructive to geopolymer properties than sulfate attack or acid rain *** solidification/stabilization of Cr is mainly attributed to the following reasons:a)The chemical binding of Cr is related to the formation of Cr-containing hydrates(eg,magnesiochromite((Mg,Fe)(Cr,Al)_(2)O_(4)))and doping into N-A-S-H gel and C-A-S-H gel framework;b)The physical effect is related to the encapsulation by the hydration products(e g,N-A-S-H gel and C-A-S-H gel).This study provides a reference for the treatment of hazardous Cr-containing wastes by solid waste-based geopolymers.

关键词： chromium solidification/stabilization geopolymer red mud durability

Aberrant DNA methylation patterns in cultured mouse embryos

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Progress in Natural Science:Materials International 2005年第12期15卷 1079-1083页

作者： HOU Jian,CUI Xiuhong,lei Tinghua,liu lei,AN Xiaorong and CHEN Yongfu State Key Laboratory for Agrobiotechnology and Department of Animal Physiology,College of Biological Science,China Agricultural University,Beijing 100094,China State Key Laboratory for Agrobiotechnology and Department of Animal Physiology College of Biological Science China Agricultural University Beijing 100094 China

Mouse early embryos undergo genome-wide demethylation and remethylation events during pre-implantation *** methylation reprogramming is thought to be associated with development *** immunofluorescence staining with an antibody against 5-methylcytosine (MeC),we examined the genome methylation patterns of mouse embryos cultured in *** results did not show the difference in staining patterns between development-blocked two-cell embryos that cultured in vitro and the two-cell embryos that were freshly collected from the donor *** in vitro-arrested morulae displayed a strong positive staining when compared to the morulae freshly collected from the donor *** the blastocyst stage,although most embryos showed the expected methylation patterns,with highly stained inner cell mass (ICM) and weekly stained trophectoderm (TE),a proportion of embryos were dimly stained in both ICM and *** results indicated that the methylation profile of the embryos could be changed by culturing in vitro when the embryos were in the transition from morulae to blastocyst.

关键词： methylation mouse embryo 5-methylcytosine antibody

Atomistic study on the microscopic mechanism of grain boundary embrittlement induced by small dense helium bubbles in iron

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Nuclear Science and Techniques 2024年第3期35卷 84-95页

作者： lei Peng Yong-Jie Sun Jing-Yi Shi Yi-Fei liu Shang-Ming Chen liu-liu Li State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion *** order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics *** results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile *** atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation ***,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at *** bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation ***,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.

关键词： Helium bubble Grain boundary Embrittlement Reduced activation ferritic martensitic steel Molecular dynamics Bain path

HIV Infection and Associated Factors Among Out-of-School MSM Aged 16–24 Years—6 Cities and Tianjin Municipality,China,2022–2023

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China CDC weekly 2024年第3期6卷 45-50页

作者： Hui liu Qiyu Zhu lei Zhang Yujing liu Peng Xu Mengjie Han National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Chinese Association of STD and AIDS Prevention and Control BeijingChina Beijing Chaoyang Kangzhong Health and Education Center BeijingChina

What is already known about this topic?Approximately 80%of newly diagnosed human immunodeficiency virus(HIV)cases among individuals aged 15–24 years in China are attributed to out-ofschool *** is added by this report?This study presents findings on HIV prevalence and comprehensive insights into HIV service utilization,risky behaviors,and prevention knowledge among young out-of-school men who have sex with men(MSM)aged 16–24 years in *** population exhibits a disproportionately high burden of HIV,with only 51.6%of HIV cases previously *** are the implications for public health practice?HIV services should be expanded to include these key *** interventions are needed to remove barriers to regular HIV services faced by young key populations.

关键词： prevention remove expanded

Parallel Implementation of the CCSDS Turbo Decoder on GPU

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China Communications 2024年第10期21卷 70-77页

作者： liu Zhanxian liu Rongke Zhang Haijun Wang Ning Sun lei Wang Jianquan School of Computer&Communication Engineering University of Science and Technology BeijingBeijing 100083China School of Electronic and Information Engineering Beihang UniversityBeijing 100191China Beijing Engineering and Technology Research Center for Convergence Networks and Ubiquitous Services Institute of Artificial IntelligenceUniversity of Science and Technology BeijingBeijing 100083China School of Information Engineering Zhengzhou UniversityZhengzhou 450001China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China

This paper presents a software turbo decoder on graphics processing units(GPU).Unlike previous works,the proposed decoding architecture for turbo codes mainly focuses on the Consultative Committee for Space Data Systems(CCSDS)***,the information frame lengths of the CCSDS turbo codes are not suitable for flexible sub-frame parallelism *** mitigate this issue,we propose a padding method that inserts several bits before the information frame *** obtain low-latency performance and high resource utilization,two-level intra-frame parallelisms and an efficient data structure are *** presented Max-Log-Map decoder can be adopted to decode the Long Term Evolution(LTE)turbo codes with only small *** proposed CCSDS turbo decoder at 10 iterations on NVIDIA RTX3070 achieves about 150 Mbps and 50Mbps throughputs for the code rates 1/6 and 1/2,respectively.

关键词： CCSDS CUDA GPU parallel decoding turbo codes

Strengthening Network Security: Deep Learning Models for Intrusion Detectionwith Optimized Feature Subset and Effective Imbalance Handling

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Computers, Materials & Continua 2024年第2期78卷 1995-2022页

作者： Bayi Xu lei Sun Xiuqing Mao Chengwei liu Zhiyi Ding School of Cyber Science and Engineering Zhengzhou UniversityZhengzhou450000China Three Academy Information Engineering UniversityZhengzhou450001China The 3rd Research Department Nanjing Research Institute of Electronic EngineeringNanjing210007China

In recent years,frequent network attacks have highlighted the importance of efficient detection methods for ensuring cyberspace *** paper presents a novel intrusion detection system consisting of a data prepro-cessing stage and a deep learning model for accurately identifying network *** have proposed four deep neural network models,which are constructed using architectures such as Convolutional Neural Networks(CNN),Bi-directional Long Short-Term Memory(BiLSTM),Bidirectional Gate Recurrent Unit(BiGRU),and Attention *** models have been evaluated for their detection performance on the NSL-KDD *** enhance the compatibility between the data and the models,we apply various preprocessing techniques and employ the particle swarm optimization algorithm to perform feature selection on the NSL-KDD dataset,resulting in an optimized feature ***,we address class imbalance in the dataset using focal ***,we employ the BO-TPE algorithm to optimize the hyperparameters of the four models,maximizing their detection *** test results demonstrate that the proposed model is capable of extracting the spatiotemporal features of network traffic data *** binary and multiclass experiments,it achieved accuracy rates of 0.999158 and 0.999091,respectively,surpassing other state-of-the-art methods.

关键词： Intrusion detection CNN BiLSTM BiGRU attention