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Channel estimation based on distributed compressed sensing in amplify-and-forward relay networks

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The Journal of China Universities of Posts and Telecommunications 2010年第5期17卷 44-49页

作者： WANG Dong-hao NIU Kai HE zhi-qiang TIAN Bao-yu School of Information and Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In orthogonal frequency-division multiplexing （OFDM） amplify-and-forward （AF） relay networks,in order to exploit diversity gains over frequency-selective fading channels,the receiver needs to acquire the knowledge of channel state information （CSI）.In this article,based on the recent methodology of distributed compressed sensing （DCS）,a novel channel estimation scheme is *** joint sparsity model 2 （JSM-2） in DCS theory and simultaneous orthogonal matching pursuit （SOMP） are both introduced to improve the estimation performance and increase the spectral *** results show that compared with current compressed sensing （CS） methods,the estimation error of our scheme is reduced dramatically in high SNR region while the pilot number is still kept small.

关键词： channel estimation DCS relay networks SOMP

Cap morphology after small-incision lenticule extraction and its effects on intraocular scattering

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International Journal of Ophthalmology(English edition) 2018年第3期11卷 456-461页

作者： Dan Fu Lin Wang Xing-Tao Zhou zhi-qiang yu Eye and ENT Hospital of Fudan University Shanghai 200031 China Myopia Key Laboratory of the Health Ministry Shanghai 200031 China

AIM： To investigate cap morphology after small-incision lenticule extraction （SMILE） and its effects on intraocular scattering. METHODS： Sixty-five eyes of 33 patients undergoing SMILE were enrolled. In addition to regular evaluation, Fourier-domain optical coherence tomography was used to investigate cap thickness at ld, lwk, 1 and 3mo postoperatively. The optical quality including modulation transfer function cutoff frequency, Strehl ratio, Optical Quality Analysis System （OQAS） values, and objective scattering index （OSI）, were evaluated using OQASTM. RESULTS： Cap thickness decreased from ld to lwk （P〈0.001）, but remained higher than intended thickness of 120 μm after 3mo （P〈0.001）. Cap thickness in central area was thinner than that of in the paracentral and peripheral areas （P〈0.0001）. Total number of microdistortions decreased from ld to 3mo （P〈0.0001）. Pearson analysis revealed a weak correlation between OSI and standard deviation of cap thickness at ld and lmo, as well as between range of cap thickness and OSI at 1mo. No correlation was found between microdistortion and OSI, but a negative correlation existed between microdistortion and range at ld and lmoafter surgery. CONCLUSION： The corneal cap tends to be more accurate and regular with time lapse. Better cap morphology tends to contribute less intraocular scattering in the eyes undergoing SMILE.

关键词： corneal cap intraocular scattering microdis-tortion small-incision lenticule extraction

Experimental study on jet pulse assembly design and numerical simulation

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维普期刊数据库

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Petroleum Science 2020年第1期17卷 222-231页

作者： Liang Xue Hu Han Dian Wang Xian-Bo Liu He Liu zhi-qiang yu China University of Petroleum–Beijing Beijing 102249China Bohai Drilling Engineering Technology Research Institute Tianjin 300280China

Jet pulse assembly is one of the main components of jet hydraulic *** pressure wave characteristics produced by jet pulse assembly have an important influence on the performance of the *** this paper,the structure and working principle of jet pulse assembly are studied,the mechanical analysis model of piston rod is established,the dynamic resistance ratio formula of jet pulse assembly is deduced,and the numerical simulation test of 89-mm jet pulse assembly structure parameters is carried *** results show that the piston rod downward stroke is driven by both the jet element driving force and the throttle plate load driving force,and can stably *** driving force of the piston rod upward stroke jet element is opposite to the load acting force of the throttle disc,and the jet driving force needs to be greater than the load resistance of the throttle disc to stably *** dynamic resistance ratio formula is *** the area of the end of the piston rod is reduced,the resistance of the throttle disc is reduced and the jet power is increased,thus solving the problem of insufficient power of the piston rod in the upstroke and ensuring the normal operation of the *** groups of numerical simulation tests were carried out,and it was found that the pressure amplitude and pressure drop of the tool decreased significantly with the increase of the tool size,and the error between the numerical simulation value and the theoretical calculation value was less than 9%,which verified the correctness of the *** is suggested to select tools on site according to the drilling construction situation to ensure the drilling effect.

关键词： Friction reduction and torsion Jet pulse assembly Dynamic resistance ratio formula Pressure amplitude Numerical simulation

Extrusion process of 304L H-shaped stainless steel used in passive residual heat removal heat exchanger

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Nuclear Science and Techniques 2019年第4期30卷 70-79页

作者： Lei-Feng Tuo Gen-Shu Zhou zhi-qiang yu Xi-Tang Kang Bo-Wen Wang State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Stainless Steel Tube Branch Company Taiyuan Iron & Steel Group CO.LTD Stainless Steel Tube Branch Company Taiyuan Iron & Steel (Group) CO.LTD

304L H-shaped stainless steel is used as the support frame of the passive residual heat removal heat exchanger(PRHR HX) in a nuclear fission reactor. The extrusion process is adopted to manufacture the 304L H-shaped stainless steel. Finite element method simulation is herein used to analyze metal flow characteristics, optimize the extrusion die, and predict the extrusion force at different temperatures and speeds. A Φ400-mm container and Φ388-mm forging billet are selected, and the 304L H-shaped stainless steel is successfully manufactured using a Germany SMS 60 MN horizontal extruder. The mechanical properties and microstructure of the manufactured 304L H-shaped stainless steel meet the requirements of the PRHR HX, and the surfaces of the product pass the dye penetration test. The H-shaped stainless steels are used in Haiyang nuclear power plant in Shandong Province.

关键词： PRHR HX Support frame Extrusion process 304L H-shaped stainless steel

Optimization of extrusion process parameters of Incoloy028 alloy based on hot compression test and simulation

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Transactions of Nonferrous Metals Society of China 2017年第11期27卷 2464-2473页

作者： zhi-qiang yu Gen-shu ZHOU Lei-feng TUO Cong-fei SONG State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University Xi’an 710049 China Stainless Steel Tube Branch Company Taiyuan Iron & Steel (Group) Co. Ltd. Taiyuan 030003 China

True stress?true strain curves of Incoloy028alloy at high temperature and strain rate were investigated by hot compression *** curves show that the maximum flow stress decreases with the increase in temperature and the decrease in strain *** simulation was employed to investigate the influence of temperature,extrusion speed and friction coefficient on the extrusion load,stress,strain and strain rate in the extrusion *** increase of extrusion temperature results in decrease of load and deformation resistance,but has little influence on strain and strain *** extrusion speed changes between200and350mm/s,no obvious change about extrusion load can be *** peak value up to42500kN emerges in the extrusion load curve and the extrusion process becomes unstable seriously when extrusion speed rises up to400mm/*** stress and strain rate increase with the raise of extrusion *** friction coefficient is between0.02and0.03,deformation resistance is about160MPa and the strain rate can be limited below70s?*** production of Incoloy028tube verifies the optimized parameters by FEM simulation analysis,and mechanical tests results of the products meet the required properties.

关键词： Incoloy028 alloy hot extrusion compression process parameter FEM simulation

Ionizable drug delivery systems for efficient and selective gene therapy

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Military Medical Research 2023年第6期10卷 818-847页

作者： yu-Qi Zhang Ran-Ran Guo Yong-Hu Chen Tian-Cheng Li Wen-Zhen Du Rong-Wu Xiang Ji-Bin Guan yu-Peng Li yuan-yu Huang zhi-qiang yu Yin Cai Peng Zhang Gui-Xia Ling Faculty of Medical Device Shenyang Pharmaceutical UniversityShenyang 110016LiaoningChina Wuya College of Innovation Shenyang Pharmaceutical UniversityShenyang 110016LiaoningChina School of Pharmacy Yanbian UniversityYanji 133002JilinChina School of Pharmacy Shenyang Pharmaceutical UniversityShenyang 110016LiaoningChina Masonic Cancer Center University of MinnesotaMinneapolisMN 55455USA Masonic Cancer Center and Department of Medicinal Chemistry University of MinnesotaMinneapolisMN 55455USA Advanced Research Institute of Multidisciplinary Science School of Life ScienceSchool of Medical TechnologyKey Laboratory of Molecular Medicine and BiotherapyKey Laboratory of Medical Molecule Science and Pharmaceutics EngineeringBeijing Institute of TechnologyBeijing 100081China Department of Laboratory Medicine Dongguan Institute of Clinical Cancer ResearchAffiliated Dongguan HospitalSouthern Medical UniversityDongguan 523018GuangdongChina Department of Health Technology and Informatics The Hong Kong Polytechnic UniversityHong KongHong Kong SARChina

Gene therapy has shown great potential to treat various diseases by repairing the abnormal gene ***,a great challenge in bringing the nucleic acid formulations to the market is the safe and effective delivery to the specific tissues and *** be excited,the development of ionizable drug delivery systems(IDDSs)has promoted a great breakthrough as evidenced by the approval of the BNT162b2 vaccine for prevention of coronavirus disease 2019(COVID-19)in *** with conventional cationic gene vectors,IDDSs can decrease the toxicity of carriers to cell membranes,and increase cellular uptake and endosomal escape of nucleic acids by their unique pH-responsive *** the progress,there remain necessary requirements for designing more efficient IDDSs for precise gene ***,we systematically classify the IDDSs and summarize the characteristics and advantages of IDDSs in order to explore the underlying design *** delivery mechanisms and therapeutic applications of IDDSs are comprehensively reviewed for the delivery of plasmid DNA(pDNA)and four kinds of *** particular,organ selecting considerations and high-throughput screening are highlighted to explore efficiently multifunctional ionizable nanomaterials with superior gene delivery *** anticipate providing references for researchers to rationally design more efficient and accurate targeted gene delivery systems in the future,and indicate ideas for developing next generation gene vectors.

关键词： Ionizable nanomaterials Ionizable drug delivery systems(IDDSs) Nucleic acids Gene therapy

Precise Asymptotics in Limit Theorems for a Supercritical Branching Process with Immigration in a Random Environment

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1850-1874页

作者： Chun Mao HUANG Rui ZHANG zhi qiang GAO Department of Mathematics Harbin Institute of Technology(Weihai)Weihai 264209P.R.China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

Let(Zn)be a supercritical branching process with immigration in an independent and identically distributed random *** necessary moment conditions,we show the exact convergence rate in the central limit theorem on log Zn and establish the corresponding local limit theorem by using the moments of the natural submartingale and the convergence rates of its *** similar approach and with the help of a change of measure,we also present the so-called integrolocal theorem and integral large deviation theorem to characterize the precise asymptotics of the upper large deviations.

关键词： Branching process with immigration random environment central limit theorem large deviation

Harmful evaluation of heavy metals from soil layer to the groundwater: Take the Jilin Hunchun Basin as an example

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China Geology 2024年第1期7卷 116-124页

作者： Xiao-Dong Guo qiang Liu Hui-Rong Zhang Xu-Fei Shi Chuan-yu Qin zhi-qiang Zhang Shenyang Geological Survey Center China Geological SurveyMinistry of Natural ResourcesShenyang 110034China Key Laboratory of Black Land Evolution and Ecological Effects Shenyang 110034China New Energy and Environment College Jilin UniversityChangchun 130026China Jilin Hydrogeological Survey Institute Changchun 130026China

The continuous enrichment of heavy metals in soils has caused potential harm to *** methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous *** on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is *** on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,*** results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending *** content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 *** harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or *** evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.

关键词： Soil heavy metals As+Hg+Cu+Pb+Zn+Ni+Cd Environmental capacity Groundwater Hazard degree Migration flux model Agricultural geological survey engineering Hunchun Basin Jilin Province

Design and fabrication of lightweight AlCrFeNiTi_(x) compositionally complex alloys with exceptional specific strength

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Rare Metals 2024年第7期43卷 3314-3328页

作者： Jun-zhi Li Wei-Zong Bao Jie Chen Bo-Hua yu Kun Zuo Tian Gao Ze-yun Cai Guo-qiang Xie School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

This study focuses on compositionally complex alloys(CCAs),aiming to achieve a balance between high strength and low density for new energy and aerospace *** composition of AlCrFeNiTi_(x) CCAs is strategically guided by employing density functional theory and the theoretical design of thermodynamic *** CCAs,particularly AlCrFeNiTi_(0.25) alloy,demonstrate remarkable specific yield strength(1640.8 MPa) and 22.7% maximum *** incorporation of Ti facilitates the formation of lightweight and high-strength L2_(1)phase,contributing to the overall high specific *** effects of grain boundary strengthening,solid solution strengthening,Orowan strengthening and Peierls flow stress further enhance *** exploration of micros tructural changes during fracture reveals the role of ordered phases in suppressing crack propagation and absorbing energy within disordered phases,thereby improving the toughness and fracture resistance of *** methods and discoveries establish a robust foundation for advancing the development of novel lightweight CCAs.

关键词： Lightweight Compositionally complex alloys Specific yield strength