最新刊期
      卷 0 ， 期 0 ， 2020
      • XU Xinlei LI Jian SUN Lihua XU Chunyan HE Jianhua
        Vol. 35, Issue 10, (2012)
        摘要：μ-crystallin,or CRYM,is an NADPH-dependent T3 binding protein in cytosol,has and is of pivotal roles in physiological regulation of thyroid hormone action in vivo.Human CRYM has been identified as ketimine reductase and potential regulated by T3.In this paper,the crystal structure of human CRYM is resolved at 1.9 and compared with 2I99.The differences between CRYM monomer and 2I99 are three β sheet and two 310helixes.The dimerization domain in CRYM presents a cluster of conserved residues side-chain over the Pro-R face of the cofactor NADPH.Compared the overall structure of CRYM with its structural homologs P.putida OCD and A.fulgidus AlaDH,we can deduce ketimine binding site and catalytic site in human CRYM.  
        关键词：μ-crystallin;Crystal structure;Ketimine reductase;Active site   
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        发布时间：2021-03-05
      • LI Rui HU Zhimin HU Pengfei
        Vol. 35, Issue 10, (2012)
        摘要：In this paper,a four-quadrant converter topology and the current closed-loop feedback technology are used to realize the scanning magnet power supply.The reference waveform is modulated by high frequency,which is then filtered by load inductance.The output current can be set by any programmable waveform within certain bandwidth.As a result of the current close feedback,the load current is not affected by magnetic parameters and environment changes.A 15 Hz with 12 A scan power supply has been developed and the test results are given.  
        关键词：Scanning magnet power supply;Current feedback;Modulate   
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        发布时间：2021-03-05
      • ZHANG Yuliang LEI Ge XU Guanglei ZHU Peng
        Vol. 35, Issue 10, (2012)
        摘要：Non-EPICS application needs to port to EPICS is a common issue in accelerator control system.EPICS provides an API named Portable Channel Access Server,i.e.PCAS,which can be used to port non-EPICS system to EPICS.For the convenience of using PCAS,a dynamic link library named pcasdll has been developed based on PCAS.The design and realization of pcasdll are introduced in this paper.Besides,A temperature measurement system for BEPCII e-gun timing module has been developed based on pcasdll is also discussed in this paper.  
        关键词：EPICS;PCAS   
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        发布时间：2021-03-05
      • DU Peng1,2 MI Qingru1 ZHOU Jianying1 ZHANG Yifei1 HUA Wenqiang1 ZHENG Lifang1 LI Zhong1 1
        Vol. 35, Issue 10, (2012)
        摘要：An optical X-ray beam position monitoring system has been established on Shanghai Synchrotron Radiation Facility(SSRF).The software for control,data acquisition and data processing is based on EPICS.It can capture and process a real time image to give the center position and spatial distribution of synchrotron radiations.The system has been used on SSRF beamlines and the experimental results show that the design specifications have been achieved.  
        关键词：EPICS;X-ray beam position measurement;Image data processing   
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        发布时间：2021-03-05
      • YU Yi WU Li ZHANG Qing LU Jiao LI Wenjing
        Vol. 35, Issue 10, (2012)
        摘要：In this work,efforts were made to solve the problem of high relative humidity in some areas of the Shanghai Synchrotron Radiation Facility(SSRF).Based on data analysis,theoretical demonstration and field tests,we found that the problem of high humidity was caused by two factors.The high humidity problem was solved by appropriate measures of keeping the actual operation load match to the design load of the air-conditioning systems and minimizing the outdoor air infiltration.  
        关键词：Relative humidity;Operation load;Outdoor air infiltration   
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        发布时间：2021-03-05
      • TANG Bin1,2 WU Yongpeng1 ZHANG Xiongjie1,2 WANG Haitao1,2 WANG Renbo1,2 ZHOU Shumin1 CHEN Rui1 LIU Qingcheng1 1
        Vol. 35, Issue 10, (2012)
        摘要：Uranium detection from natural γ-ray logging is an indirect method,because the uranium content must be corrected for influence factors from uranium-radium balance and radon escaping.In this article,relationship of the natural radio-nuclides and their characteristic gamma-rays is analyzed.A direct uranium quantitative detection method is proposed,based on high-precision γ-logging and the photoelectric-peak(or energy-window) from234mPa γ-ray of 1.001 MeV.In standard-model well experiments using a γ-spectrum logging instrument developed in our laboratory,and a LaBr3(Ce) detector,feasibility of this new method is verified.  
        关键词：Natural γ-ray logging;Radioactive equilibrium;234mPa Characteristic γ-ray;Direct uranium quantitative detection   
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        发布时间：2021-03-05
      • LU Yan HUANG Ning
        Vol. 35, Issue 10, (2012)
        摘要：In X-ray fluorescence(XRF) analysis,the use of filter reduces the background interference effectively,and improves the analysis sensitivity.In this paper,the MCNP5 code is used to simulate the filter effects in X-ray tube XRF.The XRF spectra by 140 keV electron beams,with filters of different materials and thicknesses,are compared.Their attenuation rates,i.e.background reduction from the original XRF spectra,are analyzed.  
        关键词：X-ray tube;X-ray spectra;Filter effect;MCNP5 simulation   
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        发布时间：2021-03-05
      • LUO Yaoyao GE Liangquan XIONG Chao XU Lipeng HUA Yongtao
        Vol. 35, Issue 10, (2012)
        摘要：The wavelet domain Wiener filter method,which combines the traditional wavelet method and the wiener filter,is established at CUT to reduce noising in as-recorded airborne gamma-ray spectra.It was used to treat an airborne gamma-ray data collected from an area in Inner Mongolia.The results showed that using this method,statistical noise could be greatly removed from the raw airborne gamma-ray spectra,and quality of the processed data is much better than those by conventional spectral denoising methods.  
        关键词：Airborne gamma-ray spectrometry;Denoising;Wavelet analysis   
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        发布时间：2021-03-05
      • LI Xiaolong1 FENG Deren1 MA Lihua1 YU Chenda2 WANG Xiangqi3 1
        Vol. 35, Issue 10, (2012)
        摘要：Against electromagnetic interference(EMI),a method based on DSP control,combining hardware protection with software reinforcement,is proposed in this paper.A repetition rate pulse source system is developed.A pulse source provides 5-way repetition rate pulses of 50 kV,with a minimum gap of 100 μs between two neighboring ways,and the pulses can be regulated continuously in 10-μs steps.A bounded-wave simulator system is used to prove feasibility of the method and the software reinforcement technology.The experimental results show that the DSP system using software reinforcement technology is well capable of reducing EMI.The system works properly in a simulated environment of repetition rate electromagnetic pulses.  
        关键词：Repetition rate EMP simulator;Software reinforcement technology;Program trap;Watchdog   
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        发布时间：2021-03-05
      • JIA Shaoxu BI Jinshun ZENG Chuanbin HAN Zhengsheng
        Vol. 35, Issue 10, (2012)
        摘要：Single event upset(SEU) effect in semiconductor devices and integrated circuits(IC) was simulated using Geant4.General structure and simulation method were established to study SEU effect accurately.Ionization and nuclear reaction mechanisms were used to generate statistical profiles of charge deposition in sensitive volume of semiconductor devices and ICs.The results showed that the device structure with a tungsten layer above the sensitive volume could be more likely to cause an SEU.  
        关键词：GEANT4;Nuclear reaction;Single event upset;Charge deposition;Cross section;Critical charge   
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        发布时间：2021-03-05
      • CAO Yuan1,2 WANG Wenke1 WANG Tieliang2 LIU Feng2 WANG Yingjie3 1
        Vol. 35, Issue 10, (2012)
        摘要：To identify the sensitive parameters in numerical simulation of radionuclide migration,a global sensitivity analysis model based on Latin hypercube sampling and Spearman partial rank correlation analysis methods is built.Sensitivities of key parameters at different periods of time are calculated.Spatial and temporal differences of parameter sensitivity are analyzed.The analysis results agree well with physical laws.This provides a basis for further work to calibrate the parameters and analyze the uncertainty.  
        关键词：Groundwater;Radionuclide migration;Sensitivity analysis   
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        发布时间：2021-03-05
      • HONG Pengfei1 YANG Lei1 FU Tingyan1 QI Zhong1 REN Zhongguo1,2 LI Dongcang1 1
        Vol. 35, Issue 10, (2012)
        摘要：In this paper,we present a method for measurement and analysis of nuclear pulse signal,with which pile-up signal is removed,the signal baseline is restored,and the original signal is obtained.The data acquisition system includes FPGA,ADC and USB.The FPGA controls the high-speed ADC to sample the signal of nuclear radiation,and the USB makes the ADC work on the Slave FIFO mode to implement high-speed transmission status.Using the LabVIEW,it accomplishes online data processing of the blind deconvolution algorithm and data display.The simulation and experimental results demonstrate advantages of the method.  
        关键词：Nuclear pulse;FPGA;USB2.0;LabVIEW;Blind deconvolution   
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        发布时间：2021-03-05
      • ZHU Jianyu XIE Wenxiong
        Vol. 35, Issue 10, (2012)
        摘要：Uranium pit attribute detection is an important subject in the research of arms control and verification technology.235U and238U which are the main isotopes of uranium having weak spontaneously γ-radioactivity,and the 235U characteristic γ-rays are of lower energy,hence the difficulty of detecting and verifying a uranium pit attribute using passive detection technique.In this paper,we explore the method to derive the multiplication factor by analyzing the intensity relationship between delayed and prompt neutron which are released from uranium pit excited by high-energy photons and outer neutron.Some reactions such as(γ,n) and(γ,2n) occur when the uranium material is excited by high-energy photons and the neutron emitted uranium nuclides will further induce uranium fission,while the outer neutron will cause scattering and induced fission.Approximation formulas about the radio of delayed-prompt neutron and the multiplication factor in different measuring conditions are obtained by analyzing the transport process,and accuracy of the formulas based on the numerical simulations is verified.  
        关键词：Delayed neutron;Active detection;Uranium pit;Multiplication factor   
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        发布时间：2021-03-05
      • LV Min ZHANG Huan ZHU Ying HUANG Qing ZHAO Yun
        Vol. 35, Issue 10, (2012)
        摘要：Graphene,a novel two-dimensional nanomaterial of sp2-bonded carbon atoms,has interested researchers in physics,chemistry and materials,because of its excellent electronic,optical and mechanical properties.And biological applications of graphene and its derivatives have been in rapid growth.The antibacterial activity of graphene oxide is always a hot topic.In this paper,we study antibacterial activity of graphene oxide(GO) by inhibition zone assay,turbidity estimation by spectrophotometer and plate count method,respectively.The results show that just GO exhibits antimicrobial activity via just the plate count method,with an inhibitory rate of about 80%.Owing to the physicochemical properties of GO,we believe that the plate count method can be used for detecting antimicrobial activity of GO.  
        关键词：Graphene oxide;Antibacterial efficacy;Inhibition zone method;Turbidity estimation by spectrophotometer;Plate count   
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        发布时间：2021-03-05
      • SUN Lu SUN Licheng YAN Changqi
        Vol. 35, Issue 10, (2012)
        摘要：The residual heat removal system of molten salt reactor designed by ORNL,using molten salt as fuel and draining the fuel into fuel drain tank after shutdown of the reactor,removes the decay heat by the circulation of water through the bayonet cooling thimbles in the fuel drain tank.According to structural features of the bayonet cooling thimbles in ORNL 10 MW molten salt reactor experiment(MSRE),this paper presents the analytical results of the influence of the width of gas gap and the width of steam riser on the heat removal ability and the natural circulation of the cooling water,etc.The analysis results show that,when the width of gas gap range from 3.1 mm to 5.1 mm,the change of heat dissipation power and natural circulation flow rate are both less than 5%;when the width of steam riser changes from 3.6 mm to 5.1 mm,the flow mass of the natural circulation change from 1.9 kg/s to 4.79 kg/s,with a slightly effect on the heat transfer efficiency of the system.  
        关键词：MSRE;Fuel drain tank;Bayonet cooling thimble;Thermal-hydraulic analysis   
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        发布时间：2021-03-05
      • HOU Zhousen ZHOU Tao CHEN Juan LUO Feng CHENG Wanxu
        Vol. 35, Issue 10, (2012)
        摘要：The realization of thorium uranium self-sustaining cycle and meet its physics and thermal-hydraulic requirements,it is an important question in the thorium uranium fuel recycling.(Th-U)O2CANFLEX43 fuel bundle includes two types of fuel elements,the ThO2elements in the inner two rings and the slightly enriched uranium(SEU) elements in the outer two rings as driving fuel rods.The three driving schemes are introduced in this paper based on different enrichment of drive fuel rods.The neutronic physics calculation by Dragon Program and the thermal-hydraulic analysis are executed.The results are as follows: at 1.4% enrichment of233U,the fuel consumption is 16 MWd/kg,the 233U production is 5.9872 g,the highest surface temperature of the fuel rod cladding is 371oC,temperature in the fuel rod center is 1830oC,and the maximum flow in the single channel is 25.4 kg/s.These parameters meet the requirements of thorium uranium self-sustaining cycle.  
        关键词：Thorium uranium self-sustaining cycle;Enrichment;SEU;ThO2;Fuel consumption   
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        发布时间：2021-03-05
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