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Prototype of an array SiPM-based scintillator Compton camera for radioactive materials detection

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Radiation Detection Technology and Methods 2019年第3期3卷 1-12页

作者： Ji‑Peng Zhang Xiu‑zuo Liang Jia‑le cai Yi Liu Xian‑chao Huang Dao‑wu Li Xiong Xiao Xiao‑yu Pang Zhi‑ming Zhang Long Wei Lei Shuai Beijing Engineering Research Center of Radiographic Techniques and Equipment Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Purpose The Compton camera,which visualizes the distribution of gamma-ray sources based on the kinematics of Compton scattering,has advantage of wide field of view,broad range of energy and compact *** In this study,we proposed a prototype of Compton camera,which included array silicon photomultiplier(SiPM)-based position-sensitive detectors,data acquisition(DAQ)system and image reconstruction *** detectors were composed of Ce-doped Gd_(3)Al_(2)Ga_(3)O_(12) scintillator arrays and pixel Si-PM *** DAQ system,symmetric charge division circuit,impedance bridge circuit and the delay coincidence algorithm were designed to record coincidence *** back-projection algorithm and list-mode maximum likelihood expectation maximization algorithm were adopted for image *** coordinate of longitude and latitude was used for image *** The performance of this Compton camera prototype system was *** results indicated that this system was able to locate a ^(137)Cs point source within 20 s with the corresponding radiation dose of~1.0μSv/*** angular resolution of point source was~7°(FWHM),and the total energy resolution of 662 keV was 7.2%.Furthermore,we succeeded in separating two point sources of different energy[^(22)Na(511 keV),^(137)Cs(662 keV)]in laboratory *** This prototype of scintillator Compton camera offers capabilities for applications like source term investigation and radioactive materials detection.

关键词： Compton imaging Scintillator Compton camera Silicon photomultipliers Image reconstruction

Effect of Astragalus membranaceus injection on the activity of the intestinal mucosal mast cells after hemorrhagic shock-reperfusion in rats

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Chinese Medical Journal 2006年第22期119卷 1892-1898页

作者： GAN Xiao-liang HEI Zi-qing Huang He-qing CHEN Li-xin LI Shang-rong cai jun Department of Anesthesiology Third Affiliated Hospital SunYat-sen University Guangzhou 510630 China School of Pharmaceutical Sciences Sun Yat-sen UniversityGuangzhou 510080 China

Background The mechanism of mucosal damage induced by ischemia-reperfusion （IR） after hemorrhagic shock is complex; mast cells （MC） degranulation is associated with the mucosal damage. Astragalus membranaceus can protect intestinal mucosa against intestinal oxidative damage after hemorrhagic shock, and some antioxidant agents could prevent MC against degranulation. This study aimed to observe the effects of astragalus membranaceus injection on the activity of intestinal mucosal mast cells （IMMC） after hemorrhage shock-reperfusion in rats Methods Thirty-two Wistar rats were randomly divided into the normal group, model group, low dosage group, （treated with Astragalus membranacaus injection, 10 g crude medication/kg） and high dosage group （treated with Astragalus membranacaus injection, 20 g crude medication/kg）. The rat model of hemorrhagic shock-reperfusion was induced by hemorrhage for 60 minutes followed by 90 minutes of reperfusion. The animals were administrated with 3 ml of the test drug solution before reperfusion. At the end of study, intestinal pathology, ultrastructure of IMMC, and expression of tryptase were assayed. The levels of malondisldehyde （MDA）, TNF-α, histamine, and superoxide dismutase （SOD） activity in intestine were detected, and the number of IMMC was counted. Results The Chiu＇s score of the rats in the model group was higher than in other groups （P〈0.01）. The Chiu＇s score in the high dosage group was higher than that in the low dosage group （P〈0.05）. Hemorrhage-reperfusion induced IMMC degranulation： Astragalus membranaceus injection attenuated this degranulation. Expression of tryptase and the number of IMMC in the model group increased compared with the other groups （P〈0.01） and was significantly reduced by the treatments of Astragalus membranaceus injection at both doses. There was no significant difference between the two treatment groups （P〉0.05）. MDA content and concentration of TNF-α in the model group were higher than that in the oth

关键词： Astragalus membranaceus injection hemorrhage shock reperfusion intestinal mucosal mast cells histamine tumor necrosis factor-α

Calorimetric Studies on Enthalpy Relaxation in Maltitol Glass Transition Based on Phenomenological Models

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Chemical Research in Chinese Universities 2012年第6期28卷 1078-1085页

作者： YE Bin GAO cai YANG Suo LIU Xiang-nong JIANG Bin School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 P. R. China

To investigate the enthalpy relaxation behavior of maltitol glass system,differential scanning calorimetry（DSC） was used to obtain the specific heat capacity[C p（T）] near the glass transition temperature（T g） at different cooling rates ranged between 1 and 20 K/*** phenomenological models of enthalpy relaxation,ToolNarayanaswamy-Moynihan（TNM） model,Adam-Gibbs-Vogel（AGV） model and Gómez Ribelles（GR） model,were used to simulate the experimental *** models＇ parameters were obtained via a curve-fitting *** results indicate that TNM and AGV models gave the almost identical prediction powers and can reproduce the curves of experimental C p（T） very ***,the prediction power of GR model evolved from configurational entropy approach is not so good as those of TNM and AGV *** particular,the metastable limit state parameter（δ） introduced by Gómez Ribelles has insignificant effect on the enthalpy relaxation of the small molecular hydrogen-bonding glass system.

关键词： Differential scanning calorimetry(DSC) Maltitol Glass transition Enthalpy relaxation Tool-Narayanaswamy-Moynihan(TNM) model Adam-Gibbs-Vogel(AGV) model Gómez Ribelles(GR) model Dynamic fragility

Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺研究

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原子能科学技术 2007年第z1期41卷 365-369页

作者：齐立君蔡洪涛中国原子能科学研究院反应堆工程研究设计所北京102413 中国原子能科学研究院反应堆工程研究设计所北京102413

采用BNi-5钎料,对Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺进行试验研究,对试验钎焊的接头进行了密封性能检验、抗热冲击性能试验、接头界面区微观分析以及钎缝拉伸强度试验.通过分析试验结果,确定了Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺规... 详细信息

采用BNi-5钎料,对Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺进行试验研究,对试验钎焊的接头进行了密封性能检验、抗热冲击性能试验、接头界面区微观分析以及钎缝拉伸强度试验.通过分析试验结果,确定了Nb-1Zr与1Cr18Ni9Ti高温真空钎焊工艺规范参数.

关键词： Nb-1Zr 1Cr18Ni9Ti 真空钎焊

Optimization of magnetic separation process for iron recovery from steel slag

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Journal of Iron and Steel Research International 2017年第2期24卷 165-170页

作者： Yuan-pei Lan Qing-cai Liu Fei Meng De-liang Niu Heng Zhao Department of Metallurgy Engineering College of Material Science & Engineering Chongqing University Chongqing 400044 China Chongqing Materials Research Institute Chongqing 400707 China

To improve the efficiency of iron recovery from steel slag and reduce the wear-and-tear on facilities, a new method was proposed by adding a secondary screen sizer to the magnetic separation process according to grain size distribution of magnetic iron （M-Fe） in the slag. The final recycling efficiency was evaluated by calculating the percentage of recycled M-Fe to the maximum amount of M-Fe that could be recovered. Three types of slags, namely basic oxygen furnace slag, desul- furization slag, and iron ladle slag, were studied, and the results showed that the optimized re- covery efficieneies were 93.20%, 92. 48%, and 85.82% respectively, and the recycling efficien eies were improved by 9.58%, 7.11%, and 6.24% respectively. Furthermore, the abrasion between the mill equipment and the remaining slags was significantly reduced owing to the efficient recovery of larger M-Fe particles. In addition, the using amount of grinding balls was reduced by 0. 46 kg when every 1 t steel slag was processed.

关键词： Steel slag Magnetic separation Iron recovery Recovery efficiency Abrasion

基于乡里社会的十六国胡汉民族关系——以华北与关中地区诸政权为例证

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上海大学学报（社会科学版） 2019年第5期36卷 39-52页

作者：蔡丹君中国人民大学文学院

十六国时期的胡汉民族关系,是在乡里社会生活基础上存续的。胡主先是依赖同乡建立政权,吸纳在地乡党入仕,同时,扶植流亡的乡里宗族,设立侨郡,使之壮大,既而恢复乡里选举制度,加强对乡里人才的拔擢与管理。这些都说明了胡主对乡里社会的... 详细信息

十六国时期的胡汉民族关系,是在乡里社会生活基础上存续的。胡主先是依赖同乡建立政权,吸纳在地乡党入仕,同时,扶植流亡的乡里宗族,设立侨郡,使之壮大,既而恢复乡里选举制度,加强对乡里人才的拔擢与管理。这些都说明了胡主对乡里社会的深刻理解和实际控制。在此过程中,他们获得了乡里宗族的支持,甚至有些胡主及其家族自身也壮大为乡里宗族。围绕乡里社会生活,展开对乡党、乡里宗族、乡里制度的经营,是胡主深化和加强自身统治,并实现民族融合的重要途径。认识到这一点,有助于进一步理解复杂的十六国胡汉民族关系。

关键词：十六国胡族乡里社会

Mitigation measures of the electric field in the medium-voltage power module:Effect of voltage types and recommendations for designers

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High Voltage 2021年第5期6卷 836-849页

作者： Zhizhao Huang cai Chen Yong Kang Stig Munk-Nielsen Christian Uhrenfeldt State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhanChina Department of Energy Technology Aalborg UniversityAalborgDenmark

In the medium‐voltage silicon carbide device power module,the higher voltage level will induce higher electric field stress in critical internal points such as the edge of the conductor on the direct bonded copper(DBC)*** can lead to partial discharge and subsequently accelerated ageing of the insulating medium in the ***,it is important to reduce the high electric field ***,the related technical methods of electric field control are reviewed and compared by combining the ease of implementation in real power module and the field control *** addition,systematic explanations of the electric field drift and influencing factors of the electric field strength under different voltage types within different module structures are ***,for half‐bridge power modules with different substrates structures,sug-gestions on how to implement non‐linear field‐dependent materials to reduce the electric field strength are given.

关键词： power field measures

Effects of land uses on soil physic-chemical properties and erodibility in collapsing-gully alluvial fan of Anxi County,China

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Journal of Integrative Agriculture 2016年第8期15卷 1863-1873页

作者： DENG Yu-song XIA Dong cai Chong-fa DING Shu-wen College of Resources and Environment Huazhong Agricultural University Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River) Ministry of Agriculture

the National Key Technologies R＆D Program of China during the 12th Five-Year Plan period （2011BAD31B00）

关键词： land use soil physic-chemical properties soil erodibility collapsing gully alluvial fan Anxi

Effect of plough pans on the growth of soybean roots in the black-soil region of northeastern China

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Journal of Integrative Agriculture 2017年第10期16卷 2191-2196页

作者： DONG Wen-cai FU Qiang WANG Quan-jiu CAO Cheng-peng College of Water Conservancy and Architecture Northeast Agricultural University Institute of Water Resources Xi'an University of Technology

Plough pans （PPs）, common in the black-soil region of northeastern China, have significant effects on the root systems of crops. We conducted a field experiment to study the distribution of soybean roots under the influence of PPs. The soybean roots showed compensatory growth above the PP, with higher root length and weight in soil with a PP compared to those without a PP. Roots were heavier and longer in the 15-75 cm soil layer without a PP than with a PP. Soil porosity was lower in the PP and the soil below the PP, which likely decreased the oxygen content of the soil and induced more growth of roots above the PP. The PP is also likely to decrease infiltration of rain-water and hinder the migration of nitrate downward, which in turn increased the density and length of soybean root hairs, which, hence, promoted growth.

关键词： compensatory growth plough pans root characteristics soybean