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Improving seeking precision by utilizing ghost imaging in a semi-active quadrant detection seeker

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Chinese Journal of Aeronautics 2021年第12期34卷 171-176页

作者： Siyuan WANG lijing li Wen CHEN Mingjie SUN Department of Opto-electronic Engineering Beihang UniversityBeijing 100083China

Conventional semi-active laser guidance takes advantage of the laser designator to illuminate the stable and uniform laser spot on target *** seeker collects the reflected light by a quadrant detector and outputs the relative position information to guide the missile to the illuminating laser ***,the designation and guidance accuracy could be jeopardized by the randomly drifting of laser spot caused by the instability of designation platform and air *** this work,ghost imaging technique is adapted to a quadrant detector semi-active seeker by utilizing structured illumination on the *** a series of structured illumination masks,the signals from the quadrant detector are multiplexed to perform calculation of the target relative position as well as image reconstruction of the illuminated area *** target recognition methods could be further applied to the reconstructed image to calculate the designating error and correct the *** results of simulation and experiment demonstrate that the proposed method could improve the guidance accuracy in many circumstances which would lead to attacking deviation if conventional semi-active laser guidance is used.

关键词： Digital micro-mirror device Ghost imaging Guidance system Image acquisition Semi-active laser seeker

Network pharmacology and molecular docking study on the effect of Kaempferol in treatment of metabolic associated fatty liver disease

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Journal of Traditional Chinese Medicine 2022年第5期42卷 788-794页

作者： ZHOU Kaixuan ZHANG Dong BAO Huiwei li lijing College of Pharmacy Changchun University of Chinese MedicineChangchun 130117China

OBJECTIVE: To study therapeutic effect of kaempferol on metabolic associated fatty liver disease(MAFLD) by network pharmacology and molecular docking combined with cell experiments. METHODS: First, use the Swiss Target Prediction database to predict the targets of kaempferol, and collect the targets of MAFLD through the Disgenet database and the Gene Cards database. Then, the common target of kaempferol and MAFLD was enriched and analyzed by the Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes, and the protein-protein interaction(PPI) network was constructed through the string database to obtain the key targets, and carry out molecular docking of key targets with kaempferol;In cell experiment, oleic acid induced steatosis in Hep G2 cells, which was intervened by kaempferol, the level of triglyceride(TG) was detected, the lipid deposition was observed by oil red O staining, and the protein expression was detected by Western blot. RESULTS: The results showed that there are 33 common targets for kaempferol and MAFLD. The biological process of GO is related to the regulation of protein kinase B, cell apoptosis, inflammatory factors, lipoxygenase, etc. Its action pathway is related to the phosphatidylinositol-3-kinase and protein kinase B(PI3K-AKT) signaling pathway, hypoxia-inducible factor 1 signaling pathway, forkhead box protein O signaling pathway, AMP-activated protein kinase signaling pathway, tumor necrosis factor signaling pathway, etc., the key targets are protein kinase B(AKT1), prostaglandin G/H synthase 2, matrix metalloproteinase-9, epidermal growth factor receptor, and the molecular docking of kaempferol with the four key targets shows good binding properties. Cell experiments show that kaempferol can reduce cell TG levels, reduce lipid deposition, increase the expression of PI3K, AKT, and beclin-1, and reduce the expression of caspase-3 and nuclear factor-kappa B. Kaempferol can treat MAFLD by regulating the PI3K-AKT signaling pathway to regu

关键词： Metabolic associated fatty liver disease kaempferol network pharmacology molecular docking simulation protein kinase B protoonco-gene proteins c-akt signaling transduction

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Effect of Alloying on the Microstructure and Fracture Toughness of Nb-Mo-Si Alloys

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稀有金属材料与工程 2009年第A3期38卷 58-61页

作者： Wei Qiang li Yang Zheng lijing Ma Chaoli li Huanxi Beijing University of Aeronautics and Astronautics Beijing 100083 China

It was found that typical Nbss /Nb5Si3 eutectic lamellar structure formed in the Nb-Mo-Si alloy. The interface between Nbss and Nb5Si3 phases was so strong that the alloy fractured mainly in the cleavage mode. In this paper, the fourth element was added with the aim of modifying interface structure. The microstructural characterization and the fracture toughness of Nb-17Si-10Mo ternary alloy doped with Ga, In, Zn and V, respectively, were investigated. It was revealed that the lamellar structure maintained with the addition of Ga and In, whereas it changed slightly with Zn and V additions. Moreover, a little increase in fracture toughness of Nb-17Si-10Mo ternary alloy was obtained through the addition of Ga and Zn.

关键词：共晶层状结构铌钼硅合金物理性能结构分析

Petrophysics characteristics of coalbed methane reservoir: a comprehensive review

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Frontiers of Earth Science 2021年第2期15卷 202-223页

作者： Qifeng JIA Dameng liU Yidong CAI Xianglong FANG lijing li School of Energy Resources China University of GeosciencesBeijing 100083China Coal Reservoir Laboratory of National Engineering Research Center of CBM Development&Utilization China University of GeosciencesBeijing 100083China

Petrophysics of coals directly affects the development of coalbed methane(CBM).Based on the analysis of the representative academic works at home and abroad,the recent progress on petrophysics characteristics was reviewed from the aspects of the scale-span porefracture structure,permeability,reservoir heterogeneity,and its controlling *** results showed that the characterization of pore-fracture has gone through three stages:qualitative and semiquantitative evaluation of porefracture by various techniques,quantitatively refined characterization of pore-fracture by integrating multiple methods including nuclear magnetic resonance analysis,liquid nitrogen,and mercury intrusion,and advanced quantitative characterization methods of pore-fracture by high-precision experimental instruments(focused-ion beam-scanning electron microscopy,small-angle neutron scattering and computed tomography scanner)and testing methods(m-CT scanning and X-ray diffraction).The effects of acoustic field can promote the diffusion of CBM and generally increase the permeability of coal reservoirs by more than 10%.For the controlling factors of reservoir petrophysics,tectonic stress is the most crucial factor in determining permeability,while the heterogeneity of CBM reservoirs increases with the enhancement of the tectonic deformation and stress *** study on lithology heterogeneity of deep and high-dip coal measures,the spatial storage-seepage characteristics with deep CBM reservoirs,and the optimizing production between coal measures should be the leading research directions.

关键词： petrophysics pore-fracture permeability heterogeneity controlling factors

Low-power system model for quantum entangled photon-pair source

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Journal of Systems Engineering and Electronics 2024年第5期35卷 1287-1294页

作者： FENG Tianxuan ZHANG Hanyi FAN Rong MA Honghao DONG Mengcheng li lijing School of Instrumentation and Optoelectronic Engineering Beihang UniversityBeijing 100191China Engineering Training Center Beihang UniversityBeijing 102206China Beijing Aerospace Automatic Control Institute Beijing 100854China

The quantum entangled photon-pair source,as an essential component of optical quantum systems,holds great potential for applications such as quantum teleportation,quan-tum computing,and quantum *** current workhorse technique for preparing photon pairs involves performing spon-taneous parametric down conversion(SPDC)in bulk nonlinear ***,the current power consumption and cost of preparing entangled photon-pair sources are relatively high,pos-ing challenges to their integration and *** this paper,we propose a low-power system model for the quantum entan-gled photon-pair source based on SPDC theory and phase matching *** model allows us to analyze the per-formance of each module and the influence of component cha-racteristics on the overall *** our experimental setup,we utilize a 5 mW laser diode and a typical type-II barium metabo-rate(BBO)crystal to prepare an entangled photon-pair *** experimental results are in excellent agreement with the model,indicating a significant step towards achieving the goal of low-power and low-cost entangled photon-pair *** achievement not only contributes to the practical application of quantum entanglement lighting,but also paves the way for the widespread adoption of optical quantum systems in the future.

关键词： low-power system model optical quantum system entangled photon-pair source spontaneous parametric down conversion

P-wave and S-wave response of coal rock containing gas-water with different saturation: an experimental perspective

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Frontiers of Earth Science 2023年第1期17卷 100-108页

作者： Dameng liU lijing li Zheng ZHAO Wei CHEN Yidong CAI Yongkai QIU Yingfang ZHOU School of Energy Resources China University of GeosciencesBeijing 100083China Coal Reservoir Laboratory of Natural Engineering Research Center of CBM Development&Utilization China University of GeosciencesBeijing 100083China Beijing Furuibao Energy Technology Company Beijing 100176China School of Engineering King’s CollegeUniversity of AberdeenAB243UE AberdeenUK

The acoustic response of gas and/or water saturated coal rock is fundamental for establishing the correspondence between the physical properties of the coal reservoir and the characteristics of the well-logging response,which is the technology essential for the geophysical exploration of coalbed methane(CBM).This acoustic response depends on water(Sw)and gas(Sg)saturation among other *** this study,we performed acoustic tests on dry and different gas-water saturated coal samples with different degrees of metamorphism and deformation,collected from several coal mining areas in *** tests enabled us to analyze the influence of coal type and gas-water saturation on the acoustic response of CBM *** results show that the acoustic velocity of P-wave and S-wave(Vp and Vs,respectively),and the relative anisotropy of and Vs,increased with increasing vitrinite reflectance,density,Vp and *** increasing from 0 to 100%,the growth rate of the acoustic velocity decreased with increasing vitrinite *** Vp/Vs ratio of tectonic coal was generally higher than that of primary *** growth rate of the relative anisotropy in tectonic coal was markedly higher than that in primary coal.

关键词： coal rock gas-water water saturation acoustic velocity relative anisotropy

Fast and deterministic optical phased array calibration via pointwise optimisation

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light(Advanced Manufacturing) 2023年第2期4卷 39-47页

作者： Jingwen Shan Hanyi Zhang lijing li Weijie Deng Mingjie Sun Department of Opto-electronic Engineering Beihang UniversityBeijing 100191China Key Laboratory of Optical System Advanced Manufacturing Technology Chinese Academy of SciencesChangchun.*mingjie.sun@***

Owing to the structural errors in the optical phased array,an initial random phase reduces the quality of the deflection *** most commonly applied approach to phase calibration is based on adaptive ***,adaptive optimisation approaches have slow convergence and low diffraction *** proposed a pointwise optimisation approach to achieve fast and accurate beam *** approach conducts phase calibration,combining global traversal and local searches individually for each array *** built a phase-calibration optical system containing a one-dimensional optical waveguide phase array for further verification and designed the relevant *** simulation and experimental results demonstrate that the pointwise optimisation approach accelerates the calibration process and improves the diffraction efficiency.

关键词： Beam deflection Optical phase array Phase calibration

Catalytic combustion properties of nanocomplex oxide for natural gas

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Progress in Natural Science:Materials International 2005年第11期15卷 1053-1056页

作者： MA lijing, YANG Dong, li Yingxia, BAI Shouli, CHEN Aifan and LUO Ruixian (Beijing University of Chemical Technology, Beijing 100029, China) Beijing University of Chemical Technology Beijing 100029 China

The catalysts of copper oxide supported on cerium dioxide were prepared by different methods for methane catalytic combustion. The effects of copper content in the catalysis and calcination temperatures of the catalysts on the catalytic activity are investigated. Results show that the complex oxide catalyst exhibits high catalytic activity for methane combustion due to the synergistic effect of CuO and CeO2. The catalyst prepared by impregnation is more active than that prepared by controlled coprecipitation even if CuO content is the same. When W(CuO) light-off temperature and full conversion temperature for the CH4 reaction decrease with the increasing of CuO content in the catalysts. However, when the copper content is above 13% , the excess CuO has a negative effect on the catalytic activity owing to the formation of bulk CuO particles. A proper calcinations temperature of 650℃ can lead to a high dispersion of CuO and accordingly can enhance the catalytic activity of the composites.

关键词： natural gas cerium dioxide copper oxide catalytic combustion catalytic activity.

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干涉型光纤陀螺温度漂移建模与实时补偿

航空学报 2007年第6期28卷 1449-1454页

作者：金靖宋凝芳李立京北京航空航天大学仪器科学与光电工程学院北京100083

分析了干涉型光纤陀螺(IFOG)温度漂移的影响因素,通过建立温度与陀螺模型参数之间的线性相关关系,推导出了光纤陀螺温度漂移的分布模型。为了提高陀螺温度漂移模型的适应性,设计了0.25,0.75,1.00℃/min三种变温速率的温度试验,并利用小... 详细信息

分析了干涉型光纤陀螺(IFOG)温度漂移的影响因素,通过建立温度与陀螺模型参数之间的线性相关关系,推导出了光纤陀螺温度漂移的分布模型。为了提高陀螺温度漂移模型的适应性,设计了0.25,0.75,1.00℃/min三种变温速率的温度试验,并利用小波变换的方法分离数据中的噪声和趋势项。基于温度漂移的分布模型和最小二乘误差(LSE)准则,建立了多参量联合线性模型来估计陀螺温度漂移。采用升温过程和降温过程分段建模的方法将多参量联合线性模型算法进行了简化,并在现场可编程逻辑阵列(FPGA)中分时复用一个全串行有限冲激响应(FIR)滤波器实现了陀螺温度漂移的实时估计。仿真的温度补偿结果及实时的温度补偿结果显示,该方法可以使陀螺温度漂移减小到1/10～2/10。

关键词：光纤陀螺参数估计建模温度漂移数字滤波器