最新刊期
      卷 0 ， 期 0 ， 2020
      • TIAN Feng1,2 TANG Zhongfeng1 LI Xiuhong1 WU Guozhong1 XU Hongjie1 WANG Jie1 1
        Vol. 34, Issue 7, (2011)
        摘要：tructural changes in γ-ray irradiated polytetrafluoroethylene(PTFE) were studied by synchrotron radiation X-ray scattering technique and differential scanning calorimetry.Changes in particle size,crystallinity,thickness of transition layer parameter and compactness of the irradiated PTFE were analyzed.The results show that because of the radiation degradation of PTFE,the crystalline enthalpy,melting point and crystallinity increased with the dose,while the particle size decreased and the inner structure became more compact with increasing doses.The irradiated PTFE has self-similarity.  
          
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        发布时间：2021-03-05
      • TONG Xingfan DENG Huiyu LI Zhiming
        Vol. 34, Issue 7, (2011)
        摘要：Project and data management is essential for Shanghai Synchrotron Radiation Facility(SSRF) which is a huge scientific platform for science research and technology development in China.With Product Data Management(PDM) system,SSRF improves its information service greatly.In this paper,we introduce the network structure,configuration modules and client terminals of the PDM system and the improvement in full-text retrieval subsystem,including its algorithms and details of implement in order to optimize the retrieval system.  
        关键词：SSRF;PDM;Full-Text Retrieval;Lucene   
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        发布时间：2021-03-05
      • YU Haisheng HUANG Yuying WEI Xiangjun JIANG Zheng Wang Jianqiang GU Songqi ZHANG Shuo GAO Xing
        Vol. 34, Issue 7, (2011)
        摘要：Combined with X-ray reflectivity,interface structures of Ti/Ni/Ti thin films were studied by grazing incidence XAFS method.The films in different thicknesses of Ni layers(1 nm,3 nm and 5 nm) were prepared by DC magnetron sputtering.The GI-XAFS results indicate that the inter-diffusion of Ti/Ni/Ti interface layer increased with the Ni layer thickness,being about 2 nm with the sample of 5-nm thick Ni layer.For the sample of 1-nm Ni layer,,the bond lengths of Ni-Ni and Ni-Ti coordination had shrunk because of larger degree of disorder.As thickness of the Ni layer decreases,the degree of disorder gradually increases while the coordinations of Ni-Ti increase and the coordinations of Ni-Ni decrease.  
        关键词：Grazing incidence;XAFS;Ti/Ni/Ti thin film;XRR   
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        发布时间：2021-03-05
      • BAO Liangman1 JIA Yanyan1 LEI Qiantao1,2 LIU Jiangfeng1,2 LI Xiaolin1 ZHANG Yuanxun1 LI Yan1 Zhang Guilin1 LIU Wei1 1
        Vol. 34, Issue 7, (2011)
        摘要：Proton induced λ-ray emission(PIGE) is sensitive for light element analysis and has been used for detection of low Z elements(such as Li,B,F,Na,Mg,Al,Si,etc.) in aerosol samples.It is commonly used as a complementary technique of proton induced X-ray emission(PIXE).The PIGE analysis of light elements in aerosol samples collected during a dust storm period in Shanghai was performed on the scanning proton microprobe(SPM) at Shanghai Institute of Applied Physics.The results showed that polycarbonate membrane is suitable for quantitative PIGE analysis of light elements,whereas Teflon and quartz filters contain rather high levels of F,Li,B,Na,Mg,Al and Si.The concentrations of F,Na,Mg,Al and Si in PM10 increased greatly during the dust storm period.This study demonstrated that PIGE is an effective method for analyzing light elements in aerosol and dust.  
        关键词：PIGE;Aerosol particle;Dust storm;Light element   
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        发布时间：2021-03-05
      • YE Hongsheng XU Lijun XIA Wen CHEN Kesheng LIN Min
        Vol. 34, Issue 7, (2011)
        摘要：To separate short-lived nuclide 89Rb from fission products,the separation could be started from their parent nuclides(Kr).An established frozen cold trap was rebuilt to separate inert gas Kr-Xe nuclides in two steps.The theory is based on that different gases have different saturated vapor tensions.With isotopic exchanging technology,the setup has been applied successfully in the separation of 89Rb from complicated fission products.Decontamination factors of main γ-emitters are higher than 1×104.  
          
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        发布时间：2021-03-05
      • HE Xianwen 1,2 JIANG Shan 1 HE Ming 1 RUAN Xiangdong 2 HE Guozhu1 DONG Kejun 1 LI Chaoli 1 1
        Vol. 34, Issue 7, (2011)
        摘要：In order to solve problems in measuring α-decay half-life of 210Po in metal at ultra-low temperature,a new method to check the change in α-decay half-life of 210Po nuclide in metal at 4.2 K is proposed.A significant decrease of the half-life of 210Po in metal Bi at 4.2 K is observed.The half-life of 210Po was 105.2±4.4 d at 4.2 K,while it is 138.5±1.4 d at room temperature,with difference of 24.1%.The experimental result was consistent with the prediction tendency of the Debye-Huchel model.  
        关键词：Nuclide in metal;Liquid helium temperature;Half-life;α-decay   
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        发布时间：2021-03-05
      • LUO YinHong GUO HongXia ZHANG FengQi YAO ZhiBin HE BaoPing
        Vol. 34, Issue 7, (2011)
        摘要：In this work,GaN HEMTs(High Electron Mobility Transistor) were irradiated by 0.8 and 1.2 MeV electron beams,and the irradiation effects were investigated.The results show that the device damage caused by 0.8 MeV electrons is more serious than that by 1.2 MeV electrons.Saturation drain current increase and threshold voltage negative shift are due to trapped positive charge from ionization in the AlGaN layer and N,Ga vacancy from non-ionizing energy loss in the GaN layer.Electron traps and trapped positive charges from non-ionizing in the AlGaN layer act as trap-assisted-tunneling centers that increase the gate leakage current.  
        关键词：GaN HEMT;Electron;Ionizing energy loss   
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        发布时间：2021-03-05
      • WANG Yan LI Xinxi HUANG Chaoqiang CHEN Bo
        Vol. 34, Issue 7, (2011)
        摘要：The transportation characteristic of a neutron guide is calculated by the Numeric Calculation Method Program(NCMP) composed by our group.The calculation results are compared with the results supplied by Professor V.M.Pusenkov.They are nearly the same.This shows that the NCMP can be used to calculate the neutron guide exactly.  
        关键词：Numerical calculation method;Simulative calculation;Neutron guide;Neutron transportation   
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        发布时间：2021-03-05
      • YANG Mingcheng1 SONG Weidong1 ZHANG Hongna1 ZHU Jun1 LI Zhaopeng1 ZHU Chengshen2 ZHAO Huidong1 1
        Vol. 34, Issue 7, (2011)
        摘要：Carbon nanotubes(CNTs) composite hydrogels were synthesized by radiation polymerization.The microstructure of CNTs was characterized by FT-IR and TEM.Effects of the CNTs on swelling and compressive properties of the hydrogels were investigated.Obvious changes were observed in structure of CNTs modified by combining gamma-ray irradiation and mixed acid treatment,becoming shorter tubes with opening ends,and their dispersibility and stability in water were markedly improved.The PNIPAM/CNTs composite hydrogels are temperature sensitive,with a lower critical solution temperature(LCST) of about 35°C.Compression performance of the PNIPAM/ CNTs composite hydrogels was improved,in an upward trend with increasing CNTs contents.  
        关键词：Carbon nanotubes;Composite hydrogels;Radiation polymerization;Swelling properties;Compressive properties   
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        发布时间：2021-03-05
      • AN Qian1,2 ZHANG Pingping2 LI Minghao 2 CHEN Yuhe 1 WU Lifang 2 1
        Vol. 34, Issue 7, (2011)
        摘要：Pistacia chinensis Bung seeds were irradiated to 100,200,400,600 and 800 Gy by 60Co γ-rays to study the biological effects.The results show that germination rate and survival rate of Pistacia chinensis seed decreased with increasing doses.The dose 200 Gy group has the highest variation rate and germination rate.The height of M1 seedling decreased with increasing doses.Compared with the control,dwarfing,plant type asymmetry,vein chlorosis,leaf curl,malformation and other phenotypic variation appeared with the irradiation groups of 100-400 kGy.Using RAPD,the M1 plants were investigated.Remarkable variations in the experimental plants were detected by RAPD PCR,but no variation was detected in the control plants.And the 200 kGy group has high frequencies of RAPD variation than the 100 kGy group.  
        关键词：60Co γ-ray;Irradiation;Pistacia chinensis Bunge;RAPD   
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        发布时间：2021-03-05
      • LU Wei1 WANG Tongquan2 WANG Xinggong1 LIU Xuelin1 1
        Vol. 34, Issue 7, (2011)
        摘要：In this paper,the displacement damage of energetic protons in semiconductor material of silicon is simulated using the MC software of GEANT4.The results shows a good agreement of proton NIEL(non-ionizing energy loss) value in the proton energy range from 10 MeV to 1 GeV with Jun et al and Summers/Burke et al.,who applied the Lindhard-Robinson-Akkerman partitioning functions according to energy of the recoil atoms.  
        关键词：GEANT4;Monte Carlo;Recoil Atoms;NIEL   
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        发布时间：2021-03-05
      • ZHANG Yiqiu SHI Hongcheng GU Yushen CHEN Shuguang ZHU Weimin CAI Liang XIU Yan LI Beilei
        Vol. 34, Issue 7, (2011)
        摘要：In this paper,the value of differentiating metastases from benign of bone lesions in patients with hepatocellular carcinoma using SPECT/ CT fusion imaging is evaluated.From patients with hepatocellular carcinoma(HCC) confirmed by pathology underwent bone scintigraphy,97 patients were selected to undergo SPECT/CT scanning.The bone scintigraphy and SPECT/CT fusion images were analyzed by two experienced nuclear medicine physicians together.Each patient was rated using a 3-point diagnostic confidence scale:metastasis,benign and uncertainty.The analyzed items were divided into two groups,i.e.certainty to diagnose(metastasis and benign) and uncertainty to diagnose.The percentage and its 95% confidence intervals of each group were calculated.The coincidence rate of bone metastases compared with the final diagnosis and its 95% confidence interval were calculated.The degree of certainty to diagnose on bone scintigraphy was 36.1%(35/97),its 95% confidence intervals range from 26.5% to 45.6%.The degree of uncertainty to diagnose on bone scintigraphy was 63.9%(62/97),its 95% confidence intervals range from 54.4% to 73.5%.The coincidence rate of bone metastases was 50.0%(24/48),its 95% confidence intervals range from 35.9% to 64.1%.The degree of certainty to diagnose on SPECT/CT fusion images was 81.4%(79/97),its 95% confidence intervals range from 73.7 % to 89.1%.The degree of uncertainty to diagnose on SPECT/CT fusion images was 18.6%(18/97),its 95% confidence intervals range from 10.9% to 26.3%.The coincidence rate of bone metastases was 95.8%(46/48),its 95% confidence intervals range from 90.1% to 100%.SPECT/CT fusion images provide more information than bone scintigraphy in differentiating metastases from benign lesions in patients with HCC,increase the degree of certainty to diagnose,especially increase the diagnostic accuracy in some false-negative cases diagnosed by bone scintigraphy.  
        关键词：Hepatocellular carcinoma;Neoplasm metastasis;Single photon emission computed tomography/computed tomography(SPECT/CT);Diagnosis;Bone   
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        发布时间：2021-03-05
      • WANG Mingwei ZHANG Yingjian ZHANG Yongping
        Vol. 34, Issue 7, (2011)
        摘要：This work was aimed at developing a routine for automated production of 3’-deoxy-3’-[18F]fluorothymidine(18F-FLT),a specific molecular imaging probe of tumor cell proliferation,using one-pot two-step strategy and an upgraded Explora GN module integrated with a semi-preparative HPLC system.Firstly,the nucleophilic [18F]radiofluorination of precursor BDNT with activated 18F ion was carried out at 120°C for 5 min to yield the labeled intermediate 18F-BDFT.Secondly,the acidic hydrolysis of 18F-BDFT was run at 110°C for 5 min to produce 18F-FLT after addition of HCl,and 18F-FLT was purified by HPLC.This automated production of 18F-FLT is of fast,reliable and multi-run features,being completed within 65 min with radiochemical yield of 15%-25%(without decay correction).The quality control of 18F-FLT was identical with the radiopharmaceutical requirements,especiallly the radiochemical purity of greater than 99% and high chemical purity and specific activity own to HPLC purification.  
        关键词：18F-FLT;Cell proliferation;Molecular imaging probe;Automated synthesis module   
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        发布时间：2021-03-05
      • YANG Lanlan TU Yan ZHANG Panpan QIN Nana CAI Guolong CHEN Zhongshan MA Shanle
        Vol. 34, Issue 7, (2011)
        摘要：In this paper,a particle in cell-Monte Carlo collision model is used to investigate the process of electron avalanches in gas electron multiplier(GEM),which is of great benefit to understand the GEM physics mechanism.Based on analysis of the electric field effect,electron avalanches are investigated with the time-related particle numbers and distributions in the GEM space.The relations between the GEM gain and the particle numbers deposited on the boundaries are analyzed,too.The simulation results lay the foundation for optimizing the GEM structures,working conditions based on PIC-MCC model.  
        关键词：Gas electron multiplier;PIC-MCC model;Electron avalanche;Gain   
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        发布时间：2021-03-05
      • ZHAO Tao1,2 ZHANG Haiyan1 SHAO Jie1 CAI Ping1 1
        Vol. 34, Issue 7, (2011)
        摘要：In this paper,a novel bipolar fast high-voltage pulse source is proposed.Consisting of two interleaved boost converters,it operates in discontinuous mode(DCM).By charging parasitic capacitance of the switches,short rise-time of the output pulse can be obtained.The constant filtered voltage discharges the load and forms flat top of the output voltage.A mutual reactor is introduced to realize soft switch-on.The operation mechanism is analyzed.The simulation and experimental results are given.  
        关键词：Interleaved boost converter;Bipolar fast high-voltage pulse source;Soft-switching   
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        发布时间：2021-03-05
      • GUAN Cailu ZHANG Quanhu WANG Zhongjie LIU Jie
        Vol. 34, Issue 7, (2011)
        摘要：Begin with conventional shift register of neutron coincidence counting,in this paper we study the principle and main parameters of MSR(multiplicity shift register),and simulate its function by computer code which can be used to analyze digital neutron pulse trains and output the distribution of real and real plus accidental coincidence.The simulation is accurate,with the simulation result of post-process deviating little from the given value.  
        关键词：Neutron;Multiplicity;Shift register;Simulation;Pulse trains   
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        发布时间：2021-03-05
      • ZHANG Hongfei WANG Jian LUO Chunli CUI Ke YAO Zhiming LIANG Hao JIN Ge
        Vol. 34, Issue 7, (2011)
        摘要：To develop a high-speed secure TRNG(true random number generator),a technique based on jitter of oscillator ring is introduced in this paper.Two sampling techniques are used in this design,with the output random bits having more randomness and being more stable.LFSR(linear feedback shifting register)-based post processing is used,with less hardware cost and good statistical characteristics.This TRNG is implemented on FPGA board which contains an Altera Cyclone III FPGA(field programmable gate array) and communicating with computer through a USB interface.Random bits at speeds of up to 20 Mbps could be produced.  
        关键词：True Random Number;FPGA;Oscillator ring;Jitter;Post process   
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        发布时间：2021-03-05
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