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Analyzing the Effect of the Intra-Pixel Position of Small PSFs for Optimizing the PL of Optical Subpixel Localization

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Engineering 2023年第8期27卷 140-149页

作者： Haiyang Zhan fei xing Jingyu Bao Ting Sun Zhenzhen Chen Zheng You Li Yuan Department of Precision Instrument Tsinghua UniversityBeijing 100084China State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua UniversityBeijing 100084China Beijing Advanced Innovation Center for Integrated Circuits Tsinghua UniversityBeijing 100084China Joint International Research Laboratory of Advanced Photonics and Electronics Beijing Information Science and Technology UniversityBeijing 100192China Beijing Institute of Control Engineering Beijing 100190Chin

Subpixel localization techniques for estimating the positions of point-like images captured by pixelated image sensors have been widely used in diverse optical measurement *** unavoidable imaging noise,there is a precision limit(PL)when estimating the target positions on image sensors,which depends on the detected photon count,noise,point spread function(PSF)radius,and PSF’s intra-pixel *** studies have clearly reported the effects of the first three parameters on the PL but have neglected the intra-pixel position ***,we develop a localization PL analysis framework for revealing the effect of the intra-pixel position of small *** accurately estimate the PL in practical applications,we provide effective PSF(e PSF)modeling approaches and apply the Cramér–Rao lower *** on the characteristics of small PSFs,we first derive simplified equations for finding the best PL and the best intra-pixel region for an arbitrary small PSF;we then verify these equations on real ***,we use the typical Gaussian PSF to perform a further analysis and find that the final optimum of the PL is achieved at the pixel boundaries when the Gaussian radius is as small as possible,indicating that the optimum is ultimately limited by light ***,we apply the maximum likelihood *** combination with e PSF modeling allows us to successfully reach the PL in experiments,making the above theoretical analysis *** work provides a new perspective on combining image sensor position control with PSF engineering to make full use of information theory,thereby paving the way for thoroughly understanding and achieving the final optimum of the PL in optical localization.

关键词： Optical measurement Subpixel localization Precision limit optimization Small point spread functions Centroiding Star sensors

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Review of Real-time Simulation of Power Electronics

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Journal of Modern Power Systems and Clean Energy 2020年第4期8卷 796-808页

作者： fei Li Yichao Wang Fan Wu Yao Huang Yang Liu xing Zhang Mingyao Ma School of Electrical Engineering and Automation Hefei University of TechnologyHefeiChina National and Local Joint Engineering Laboratory for Renewable Energy Access to Grid Technology HefeiChina

Real-time simulation of power electronics has been recognized by the industry as an effective tool for developing power electronic devices and *** there is no energy transfer during the course of the usage,real-time simulation has a lot of advantages in the process of development and *** the perspective of real-time simulation,this paper focuses on the main problems in modeling accuracy,system bandwidth and stability,limitations on communication interface and energy interface,and the cost of platform ***,we provide further research directions.

关键词： Hardware-in-the-loop simulation modeling and simulation of power electronics correction method power interface algorithm numerical method

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On the Relation Between Coronal Green Line Brightness and Magnetic Fields Intensity

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Research in Astronomy and Astrophysics 2022年第7期22卷 128-138页

作者： Xue-fei Zhang Yu Liu Ming-Yu Zhao Teng-fei Song Jing-xing Wang Xiao-Bo Li Zi-Han Li Yunnan Observatories Chinese Academy of SciencesKunming 650011China University of Chinese Academy of Sciences Beijing 100049China Yunnan Normal University School of Physics and Electronic InformationKunming 650000China

Two-dimensional(2 D) solar coronal magnetogram is difficult to be measured directly until *** the previous knowledge,a general relation has been noticed that the brighter green-line brightness for corona,the higher coronal magnetic field intensity may correspond *** try to further reveal the relationship between coronal green line brightness and magnetic field intensity,we use the 2 D coronal images observed by Yunnan Observatories Greenline Imaging System(YOGIS) of the 10 cm Lijiang coronagraph and the coronal magnetic field maps calculated from the current-free extrapolations with the photospheric magnetograms taken by Helioseismic and Magnetic Imager(HMI) on board the Solar Dynamics Observatory(SDO) *** our analysis,we identified the coronal loop structures and construct two-dimensional maps of the corresponding magnetic field intensity in the plane of the sky(POS) above the *** derive the correlation coefficients between the coronal brightness and the magnetic field intensity for different heights of coronal *** further use a linear combination of a Gaussian and a quadratic profile to fit the correlation coefficients distribution,finding a largest correlation coefficient of 0.82 near 1.1 R(solar radii) where is almost the top of the closed loop *** the small closed loop system identified,the correlation coefficient distributions crossing and covering the loop are *** also investigate the correlation with extended heliocentric latitude zones and long period of one whole Carrington Rotation,finding again that the maximum correlation coefficient occurs at the same *** is the first time for us to find that the correlation coefficients are high(all are larger than 0.8) at the loop-tops and showing poor correlation coefficients with some fluctuations near the feet of the coronal *** findings indicate that,for the heating of the low-latitude closed loops,both DC(dissipation of currents) and AC(dissipation of Alfvé

关键词： Sun:magnetic fields Sun:corona Stars:coronae Sun:activity Sun:atmosphere Sun:coronal mass ejections(CMEs) Sun:fundamental parameters Sun:heliosphere Sun:UV radiation

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Simulation study of high voltage GaN MISFETs with embedded PN junction

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Chinese Physics B 2020年第8期29卷 198-203页

作者： Xin-xing fei Ying Wang Xin Luo Cheng-Hao Yu College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China Key Laboratory of RF Circuits and Systems Ministry of EducationHangzhou Dianzi UniversityHangzhou 310018China

In this paper,we propose a new enhanced GaN MISFET with embedded pn junction,i.e.,EJ-MISFET,to enhance the breakdown *** embedded pn junction is used to improve the simulated device electric field distribution between gate and drain,thus achieving an enhanced breakdown voltage(BV).The proposed simulated device with LGD=15μm presents an excellent breakdown voltage of 2050 V,which is attributed to the improvement of the device electric field distribution between gate and *** addition,the ON-resistance(RON)of 15.37Ω·mm and Baliga's figure of merit of 2.734 GW·cm-2 are achieved in the optimized *** with the field plate conventional GaN MISFET(FPC-MISFET)without embedded pn junction structure,the proposed simulated device increases the BV by 32.54%and the Baliga's figure of merit is enhanced by 71.3%.

关键词： TCAD Baliga’s figure of merit(BFOM) breakdown voltage(BV)

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Syntheses, Crystal Structures and Biological Activity of the Diorganotin 2-(2-(4-Methoxybenzoyl)hydrazono)-3-phenylpropanoic Carboxylate Complexes

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Chinese Journal of Structural Chemistry 2020年第11期39卷 1965-1972页

作者： WANG Man YU fei JIANG Wu-Jiu TAN Yu-xing ZHANG Fu-xing KUANG Dai-Zhi Key Laboratory of Functional Metal-organic Compounds of Hunan Province Key Laboratory of Functional Organometallic MaterialsUniversity of Hunan ProvinceCollege of Chemistry and Materials ScienceHengyang Normal UniversityHengyangHunan 421008China

Diorganotin 2-(2-(4-methoxybenzoyl)hydrazono)-3-phenylpropanoic carboxylate complexes Ⅰ{[p-CH3 O-C6 H4 O(O)C=N-N=C(Ph CH2)COO](n-Bu)2 Sn(CH3 OH)}2 and Ⅱ {[p-CH3 O-C6 H4 O(O)C=NN=C(Ph CH2)COO](Ph CH2)2 Sn(CH3 OH)}2 have been synthesized. The complexes have been characterized by IR, 1 H, 13 C and 119 Sn NMR spectra, HRMS, elemental analysis, thermal stability analysis and the crystal structures have been determined by X-ray diffraction. The crystal of complex I belongs to triclinic system, space group P1 with a = 10.437(2), b = 11.576(3), c = 13.085(3) ?, α = 66.272(2)°, β = 86.920(3)°, γ = 73.367(3)°, Z = 2, V = 1383.3(5) ?3, Dc = 1.381 Mg·m-3, m(Mo Kα) = 0.959 mm-1, F(000) = 592, R = 0.0233 and w R = 0.0644. The crystal of complex Ⅱ is of triclinic system, space group P1 with a = 10.446(1), b = 11.720(1), c = 13.063(2) ?, α = 84.190(1)°, β = 71.610(1)°, γ = 72.624(1)°, Z = 1, V = 1448.3(3) ?3, Dc = 1.475 Mg·m-3, m(Mo Kα) = 0.925 mm-1, F(000) = 656, R = 0.0169 and w R = 0.0432. In vitro antitumor activities of both complexes were evaluated by MTT against three human cancer cell lines(NCI-H460, Hep G2 and MCF7), and two complexes exhibited good antitumor activity. The interaction between complex Ⅰ and calf thymus DNA were studied by UV-vis and fluorescence spectroscopy, the interaction of complex Ⅰ with calf thymus DNA were intercalation.

关键词： diorganotin carboxylate synthesis crystal structure biological activity

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Spark plasma sintering of tungsten-based WTaVCr refractory high entropy alloys for nuclear fusion applications

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 146-154页

作者： Yongchul Yoo Xiang Zhang fei Wang Xin Chen xing-Zhong Li Michael Nastasi Bai Cui Department of Mechanical&Materials Engineering University of Nebraska-LincolnLincolnNE 68588USA Nebraska Center for Materials and Nanoscience University of Nebraska-LincolnLincolnNE 68588USA Department of Nuclear Engineering Texas A&M UniversityCollege StationTX 77843USA

W-based WTaVCr refractory high entropy alloys (RHEA) may be novel and promising candidate materials for plasma facing components in the first wall and diverter in fusion reactors. This alloy has been developed by a powder metallurgy process combining mechanical alloying and spark plasma sintering (SPS). The SPSed samples contained two phases, in which the matrix is RHEA with a body-centered cubic structure, while the oxide phase was most likely Ta2VO6through a combined analysis of X-ray diffraction (XRD),energy-dispersive spectroscopy (EDS), and selected area electron diffraction (SAED). The higher oxygen affinity of Ta and V may explain the preferential formation of their oxide phases based on thermodynamic calculations. Electron backscatter diffraction (EBSD) revealed an average grain size of 6.2μm. WTaVCr RHEA showed a peak compressive strength of 2997 MPa at room temperature and much higher micro-and nano-hardness than W and other W-based RHEAs in the literature. Their high Rockwell hardness can be retained to at least 1000°C.

关键词： refractory high entropy alloy plasma-facing material fusion reactor spark plasma sintering

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Strain-enhanced polarization sensitivity inβ-Ga_(2)O_(3)photodetector

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 126-137页

作者： Yonghui Zhang Huili Liang fei xing Qiqian Gao Yu Feng Yuping Sun Zengxia Mei School of Physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255000China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China

Polarization-sensitive photodetection and imaging have great application value in fields such as polarization division multiplexing optical communication,remote sensing,near-field imaging and military *** a high polarization ratio has always been the research hotspot in polarization-sensitive *** this paper,we report a compression strain enhanced polarization ratio inβ-gallium oxide(β-Ga_(2)O_(3))single crystal flake.A rigorous crystallographic analysis confirmed its high crystalline quality and ***-resolved polarization Raman spectroscopy(ARPRS)was adopted to study the anisotropy of its optical *** ARPRS measurements and theoretical calculation consistently demonstrate the strong optical anisotropy in the high-qualityβ-Ga_(2)O_(3)flake.A polarization ratio of 0.96 was obtained in the flatβ-Ga_(2)O_(3)***,mechanical strain of±0.7%was introduced intoβ-Ga_(2)O_(3).An increased polarization ratio of 0.98 was achieved in the case of 0.7%compression strain,which is,to the best of our knowledge,the highest value for UVC polarization-sensitive *** corresponds to an improved polarization rejection ratio of *** work proposed a new path towards improving polarization sensitivity by applying strain engineering in the active material.

关键词： gallium oxide polarization photodetector anisotropy strain

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Formation mechanism of surface oxide layer of grain-oriented silicon steel

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Journal of Iron and Steel Research International 2021年第3期28卷 327-334页

作者： Jia-long Qiao fei-hu Guo Sheng-tao Qiu xing-zhong Zhang Hai-jun Wang National Engineering Research Center of Continuous Casting Technology China Iron&Steel Research Institute GroupBeijing100081China School of Metallurgy and Resources Anhui University of TechnologyMa’anshan243002AnhuiChina

The surface oxide layer of grain-oriented electrical steels was investigated by scanning electron *** formation mechanism and the influence on the glass film of the surface oxide layer were analyzed by the calculation of thermodynamics and *** surface oxide layer with 2.3μm in thickness is mainly composed of SiO_(2),a small amount of FeO and Fe_(2)SiO_(4).During the formation of surface oxide layer,the restriction factor was the diffusion of O in the oxide *** the initial stage of the decarburization annealing,FeO would be formed on the surface ***_(2) and silicate particles rapidly nucleated,grew and formed a granular oxide layer in the *** the oxidation layer thickens,the nucleation of new particles decreases,and the growth of oxide particles would be dominant.A lamellar oxide layer was formed between the surface oxide layer and the steel matrix,and eventually formed a typical three-layer *** the high temperature annealing,MgO mainly reacted with SiO_(2) and Fe_(2)SiO_(4) in the surface oxide layer to form Mg2SiO_(4) and Fe_(2)SiO_(4) would respond first,thus forming the glass film with average thickness of 4.87μm.

关键词： Grain-oriented silicon steel Decarburizing annealing Surface oxide layer Formation mechanism Glass film

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ADSORPTION OF TANNIN ACID ONTO AN AMINATED MACROPOROUS RESIN FROM AQUEOUS SOLUTIONS

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Chinese Journal of Polymer Science 2007年第6期25卷 621-627页

作者： Yue Sun Ai-min Li Zheng-hao fei Quan-xing Zhang Shi-he Wang Department of Municipal Engineering Southeast University Nanjing 210096 China Department of Environmental Engineering Nanjing University Nanjing 210093 China Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresourees and Environmental Protection Yancheng Teachers College Jiangsu 224002 China

A macroporous polymeric adsorbent NG-8 was synthesized with divinylbenzene using conventional suspension polymerization technique. Its aminated product NG-9 was prepared by introducing tertiary amino groups into NG-8 for removal of tannin acid from aqueous solutions. NG-9 could be used directly without a wetting process and had higher adsorption capacity than NG-8, which might be attributed to the enhanced adsorbent-adsorbate interaction due to the tertiary amino groups on the polymeric matrix. The Langmuir equation was successfully employed to describe the adsorption process. The adsorption enthalpy change further validated the uptake of tannin acid on NG-9 to be an enhanced physical adsorption because of the Lewis acid-base interaction. In addition, adsorption kinetic studies testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate maybe for the hindrance of the tertiary amino groups and water clusters built up.

关键词： Macroporous resin Tannin acid Adsorption Thermodynamics Kinetics.

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Diffusion coefficients of natural gas in foamy oil systems under high pressures

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Petroleum Science 2015年第2期12卷 293-303页

作者： Yan-Yu Zhang Xiao-fei Sun Xue-Wei Duan xing-Min Li College of Petroleum Engineering China University of Petroleum School of Geosciences China University of Petroleum The Department of Chemical and Petroleum Engineering University of Calgary Research Institute of Petroleum Exploration and Development PetroChina

The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.

关键词： Foamy oil Diffusion coefficient - Heavy oil Gas injection High pressure

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