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Study of performance of small gamma camera consisting of crystal pixel array and position sensitive photomultiplier tube

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Nuclear Science and Techniques 2005年第4期16卷 238-243页

作者： ZHU Jie LIU Shi-Tao LEI Xiao-Wen YAN Tian-Xin XU zi-Zong wang zhao-Min Department of Modern Physics University of Science and Technology of China Hefei 230026

The performance of gamma camera with NaI(Tl) array coupled with position sensitive photomultiplier tube (PSPMT) R2486 has been studied. The pixel size of NaI(Tl) crystal is 2mm×2mm and the overall dimension of the array is 48.2mm×48.2mm×5mm. There are 484 pixels in a 22×22 matrix. Because each pixel can produce a much focused light spot and restrict the spread of photons, position resolution of the gamma camera is mainly determined by pixel size. It is shown that crystal array pixel can reduce shrinkage effect and improve intrinsic position resolution greatly via restricting the spread of photons. Experimental results demonstrate that its position resolution and linearity are much improved comparing with the gamma camera using planar crystals coupled with PSPMT.

关键词：光电倍增器像素照相机 PSPMT 线性关系

Quantitatively probing interactions between membrane with adaptable wettability and oil phase in oil/water separation

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Petroleum Science 2023年第4期20卷 2564-2574页

作者： Zhong-Zheng Xu Ming-Wei zhao Yi-Ning Wu Jia-Wei Liu Ning Sun zi-zhao wang Yi-Ming Zhang Lin Li Cai-Li Dai Shandong Key Laboratory of Oilfield Chemistry School of Petroleum EngineeringChina University of Petroleum(East China)QingdaoShandong266580China Key Laboratory of Unconventional Oil&Gas Development China University of Petroleum(East China)Ministry of EducationQingdaoShandong266580China

The membrane method based on adaptive wettability shows great advantages in oil-water *** present,researches focus on the excellent application performance of the membrane material,while the quantitative analysis of interactions in oil-water separation is rarely ***,we constructed an adaptable wettability membrane with multiple polymer networks by polydopamine(PDA)and mussel-inspired amphiphilic *** on the Owens three-probe liquid method,the surface energy of the modified membrane was verified to meet the adaptive wettability conditions,with surface energies(γ-8)of 147.6 mJ m^(−2)(superhydrophilic/underwater superoleophobic)and 49.87 mJ m^(−2)(superhydrophobic/superoleophobic),*** adhesion or repulsion of the membrane to the oil phase under different conditions during the separation process was quantified by the chemical probe AFM *** addition,the oil-water selective separation mechanism was further analyzed in a simplified membrane microchannel *** results show that the different wetting produces capillary additional pressure in opposite directions,resulting in different energies to be overcome when the oil or water passes through the microchannels,thus achieving selective separation.

关键词： Adaptable wettability Selective oil/water separation Interface interaction Probe AFM technique

Experimental research on the launching system of auxiliary charge with filter cartridge structure

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Defence Technology（防务技术） 2024年第1期31卷 41-48页

作者： zi-Jun Chen Ze He Hong-Hao Ma Lu-Qing wang zhao-Wu Shen CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefeiAnhui230027PR China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefeiAnhui230026PR China

A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the *** combustion chamber of the launching system is divided into two fixed chambers,one is located in the breech chamber,and the other is arranged in the *** breech chamber charge was ignited first,and the charges in the auxiliary chambers were ignited by the high-temperature,highpressure combustible gas trailing the *** this way,the combustible gas in the auxiliary chambers could compensate for the pressure drop caused by the movement of the *** proposed device features the advantage of launching a projectile with high muzzle velocity without exceeding the maximum pressure in the *** order to obtain some internal ballistic characteristics of the launch system,some critical structure,such as the length of the filter cartridge auxiliary charge,the combustion degree of the propellant in the chamber,and the length of the barrel,are *** experimental results show that with the increased auxiliary charge length,a pressure plateau or even a secondary peak pressure can be formed,which is less than the peak *** projectile velocity increased by 23.57%,14.64%,and 7.65%when the diaphragm thickness was 0 mm,1 mm,and2 mm,*** muzzle velocity of the projectile can be increased by 13.42%by increasing the length of the *** the same charge condition,with the increase of barrel length,the energy utilization rate of propellant increases by 28.64%.

关键词： Interior ballistics Charge structures Launch system Charge design

Multi-distortion suppression for neutron radiographic images based on generative adversarial network

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Nuclear Science and Techniques 2024年第4期35卷 176-188页

作者： Cheng-Bo Meng wang-Wei Zhu Zhen Zhang zi-Tong wang Chen-Yi zhao Shuang Qiao Tian Zhang School of Physics Northeast Normal UniversityChangchun 130024China

Neutron radiography is a crucial nondestructive testing technology widely used in the aerospace,military,and nuclear ***,because of the physical limitations of neutron sources and collimators,the resulting neutron radiographic images inevitably exhibit multiple distortions,including noise,geometric unsharpness,and white ***,these distortions are particularly significant in compact neutron radiography systems with low neutron ***,in this study,we devised a multi-distortion suppression network that employs a modified generative adversarial network to improve the quality of degraded neutron radiographic *** neutron radiographic image datasets with various types and levels of distortion were built for the first time as multi-distortion suppression ***,the coordinate attention mechanism was incorporated into the backbone network to augment the capability of the proposed network to learn the abstract relationship between ideally clear and degraded *** experiments were performed;the results show that the proposed method can effectively suppress multiple distortions in real neutron radiographic images and achieve state-of-theart perceptual visual quality,thus demonstrating its application potential in neutron radiography.

关键词： Neutron radiography Multi-distortion suppression Generative adversarial network Coordinate attention mechanism

LociScan,a tool for screening genetic marker combinations for plant variety discrimination

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The Crop Journal 2024年第2期12卷 583-593页

作者： Yang Yang Hongli Tian Hongmei Yi zi Shi Lu wang Yaming Fan Fengge wang Jiuran zhao Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding Maize Research InstituteBeijing Academy of Agriculture and Forestry SciencesBeijing 100097China

To reduce the cost and increase the efficiency of plant genetic marker fingerprinting for variety discrimination,it is desirable to identify the optimal marker *** describe a marker combination screening model based on the genetic algorithm(GA)and implemented in a software tool,Loci ***-based variety discrimination power provided the largest optimization space among multiple fitness *** GA parameters,an increase in population size and generation number enlarged optimization depth but also calculation *** algorithm afforded the same optimization depth as GA but vastly increased calculation *** comparison with two other software tools,Loci Scan accommodated missing data,reduced calculation time,and offered more fitness *** large datasets,the sample size of training data exerted the strongest influence on calculation time,whereas the marker size of training data showed no effect,and target marker number had limited effect on analysis speed.

关键词： Plant variety discrimination Genetic marker combination Variety discrimination power Genetic algorithm

Ruthenium-Catalysed Asymmetric Intramolecular Isomerization/Esterification Reaction: Direct Synthesis of Chiral Dihydrocoumarins

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Chinese Journal of Chemistry 2024年第16期42卷 1828-1832页

作者： Lingzi zhao Xuchao wang Qing Qiang Xingwei zhao Feipeng Liu Shenci Lu zi-Qiang Rong Frontiers Science Center for Flexible Electronics(FSCFE) Shaanxi Institute of Flexible Electronics(SiFE)&Shaanxi Institute of Biomedical Materials and Engineering(SIBME)Northwestern Polytechnical University(NPU)127 West Youyi RoadXianShaanxi 710072China Honors College Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'anShaanxi 710072China

An asymmetric isomerization/intramolecular coupling reaction of allylic alcohols to synthesize chiral dihydrocoumarins was successfully accomplished through ruthenium *** method demonstrates a wide substrate applicability,excellent tolerance for various functional groups,and good enantioselectivities(up to 90%ee).It provides a convenient pathway to produce a diverse range ofstructurallydistinct chiral dihydrocoumarins ingoodefficiency.

关键词： Ruthenium catalysis Asymmetric isomerization Tandem reaction Chiral dihydrocoumarins Enantioselectivity

Point spread functions for a small gamma camera with pinhole collimator

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Nuclear Science and Techniques 2003年第3期14卷 195-198页

作者： LIU Shi-Tao, XU zi-Zong, wang zhao-Min, XU Shen-Bo (Department of Modern Physics, University of Science and Technology of China, Hefei 230027) Department of Modern Physics University of Science and Technology of China Hefei 230027

A set of point spread functions (PSF) has been obtained by means of Monte-Carlo simulation for asmall gamma camera with a pinhole collimator of various hole diameters. The FOV (field of view) of the camera isexpended from 45 mm to 70 mm in diameter. The position dependence of the variances of PSF is presented, and theacceptance for the 140 kev gamma rays is explored. A phantom of 70 mm in diameter was experimentally imaged inthe camera with effective FOV of only 45 mm in diameter.

关键词：点扩散函数 γ照相机针孔准直器 PSF Monte-Carlo仿真临床诊断

Design strategies of high-performance lead-free electroceramics for energy storage applications

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Rare Metals 2024年第3期43卷 853-878页

作者： Biao Guo Fei Jin Li Li zi-zhao Pan Xin-Wei Xu Hong wang Department of Materials Science and Engineering College of EngineeringSouthern University of Science and TechnologyShenzhen518055China School of Microelectronics and State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an710049China

A greater number of compact and reliable electrostatic capacitors are in demand due to the Internet of Things boom and rapidly growing complex and integrated electronic systems,continuously promoting the development of high-energy-density ceramic-based *** significant successes have been achieved in obtaining high energy densities in lead-based ferroelectric ceramics,the utilization of lead-containing ceramies has been restricted due to environmental and health hazards of ***-free ferroelectric ceramics have garnered tremendous attention and are expected to replace lead-based ceramics in the near ***,the energy density of lead-free ceramics is still lagging behind that of lead-containing ***,severely limiting their *** efforts have been made to enhance the energy storage performance of lead-free ceramics using multi-scale design strategies,and exciting progress has been achieved in the past *** review briefly discusses the energy storage mechanism and fundamental characteristics of a dielectric capacitor,summarizes and compares the state-of-the-art design strategies for high-energy-density lead-free ceramics,and highlights several critical issues and requirements for industrial *** prospects and challenges of lead-free ceramics for energy storage applications are also discussed.

关键词： Dielectric materials Lead-free ceramic Environment friendly Energy storage Design strategy

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新疆地区煤矿地质环境影响程度分析评价模型

煤炭学报 2017年第2期42卷 344-352页

作者：张紫昭隋旺华中国矿业大学资源与地球科学学院江苏徐州221116 新疆大学地质与矿业工程学院新疆乌鲁木齐830046

充分考虑矿山地质环境影响因素,结合新疆地区煤矿地质环境破坏特点,建立了适合该地区煤矿地质环境影响程度评价的指标体系和评价模型。评价指标体系由矿山开采引发或加剧地质灾害规模、地质灾害威胁人员数量、涌水量或工业废水排放量、... 详细信息

充分考虑矿山地质环境影响因素,结合新疆地区煤矿地质环境破坏特点,建立了适合该地区煤矿地质环境影响程度评价的指标体系和评价模型。评价指标体系由矿山开采引发或加剧地质灾害规模、地质灾害威胁人员数量、涌水量或工业废水排放量、矿山设施挖损或压占破坏土地后或地面塌陷后地面主导坡度、地面塌陷或挖损最大深度或压占堆积物最大高度、对土地资源的影响程度等6个因素组成。以新疆地区17个煤矿的88个评价单元作为学习样本,建立了新疆地区煤矿地质环境影响程度评价模型,采用回代估计方法对模型进行检验,符合率达96.6%。将该评价模型应用到新疆科尔克煤矿,对该煤矿的9个评价单元进行地质环境影响程度评价,评价结果表明,该评价指标体系和评价模型对新疆地区煤矿地质环境影响程度评价具有一定的参考价值,在实际应用过程中可作为规范评价的一个有力补充。

关键词：矿山地质环境煤矿评价指标体系评价模型