最新刊期
      卷 0 ， 期 0 ， 2020
      • SHEN Fei1,2 CHEN Rongchang1,2 XIAO Tiqiao1 1
        Vol. 34, Issue 6, (2011)
        摘要：The micro-CT of the X-ray imaging beamline at Shanghai Synchrotron Radiation Facility can achieve sub-micron resolution,while the data size for a single set of CT projection is often dozens of giga bytes.With the serials methods,several hours of CPU time are usually needed for processing a single set of data,while the beamline operates 24 hours a day and seven days a week,with dozens of CT data sets being collected by users every day.Conventional methods based on CPU are no longer applicable for processing such massive data sets.GPU is a highly parallel stream processor,which is capable of accelerating the CT reconstruction significantly.In this paper,CUDA programming standard is used to program the paralleled CT reconstruction.The test results show that the program running in a NVDIA GTX295 GPU can accelerate the CT reconstruction by a factor of 150.The reconstructing time could be shortened to 15 minutes or around.The reconstruction speed shall be further improved by a GPU server with more pieces of GPU chips.  
        关键词：Micro CT;Image reconstruction;Parallel processing;GPU   
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        发布时间：2021-03-05
      • YANG Jing1 GU Tingting1 ZHU Feng1 WU Xiang1 QIN Shan1 LIU Jing2 LI Xiaodong2 1
        Vol. 34, Issue 6, (2011)
        摘要：The structural phase transition and compressibility of cryolite under high pressure up to 39.7 GPa were studied by using in-situ synchrotron X-ray diffraction with a diamond anvil cell at BSRF.The experimental results show that the structure of low-pressure phase can be distorted at the high-pressure,but further structural refinement was impossible due to limit of the experimental resolution.For cryolite,the unit cell volume decreased smoothly with increasing pressures.The pressure-related variation of unit cell volume was analyzed by Birch-Murnaghan equations of state(EoS),obtaining a bulk modulus(K0) of 77(4) GPa and its pressure derivative(K0’) 3.1(4),and the K0 turn to be 69(1) GPa while the K0’ was fixed at 4.Results from theoretical simulations are well consistent with those from experiments with similar EoS parameters and the axial compressibility.  
        关键词：Cryolite;High pressure;Phase transition;Compressibility   
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        发布时间：2021-03-05
      • LIU Shilei1,2 WANG Li1,2 XU Zhongmin1 WANG Naxiu1 1
        Vol. 34, Issue 6, (2011)
        摘要：In order to measure the parallelism error of synchrotron radiation double-crystal monochromator off-line,a new method was developed at SSRF.A pencil beam interferometer improved with a cross phase plate is used to measure the parallelism error and carry out the principle experiment.This method overcomes the defects of autocollimator.It can measure the absolute parallelism of the two double crystals in two directions simultaneously and the theoretical measurement accuracy of pitch and roll is 0.89’’ and 1.79’’ in this experiment,respectively.  
        关键词：Double crystal monochromator;Parallelism;Pencil beam interferometer   
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        发布时间：2021-03-05
      • LIU Hui1,2 WANG Bing1 WANG Zhuo2 LI Ming1 KANG Yanjie1,3 BI Xiaolin1 YU Xiaohan4 FENG Weiyue1 1
        Vol. 34, Issue 6, (2011)
        摘要：In this work,CdSe@ZnS quantum dots(QDs) distributed in the QDs-exposed adult drosophila and their stage-1 larva were characterized by synchrotron radiation micro X-ray fluorescence(μ-SRXRF) and laser scanning confocal microscope(LSCM),respectively.The CdSe@ZnS QDs were exposed via the mouth to the adult drosophila.The μ-SRXRF elemental mapping of Cd,Se and Zn revealed that the elements were concentrated in the intestinal and reproductive system,indicating that QDs could accumulate in the intestinal and reproductive system.Obvious fluorescence signals were observed in the testis of stage-1 larva by LSCM technique.The results indicate the QDs via oral exposure could induce potential impact on placenta translocation and reproductive system.The results show that μ-SRXRF analysis is a novel method for the investigation of translocation of nanoparticle in the living organism.  
        关键词：μ-SRXRF;CdSe@ZnS quantum dot;Drosophila;Placenta translocation   
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        发布时间：2021-03-05
      • YANG Xiaoxu ZHOU Sizhong YAN Minqi HAN Junfeng JIANG Bo GUO Zhili DENG Xiaoguo ZHANG Zhoufeng
        Vol. 34, Issue 6, (2011)
        摘要：In this paper,the principle of double crystal monochromator in beam lines of synchrotron radiation facilities is introduced,and the technique of invariable relative height in double crystal monochromator is used to keep the height of the beam from the monochromator.A CCD imaging system and an image processing system are used for off-line test.The precision is analyzed.The results show that the measurement precision of relative beam height is primary factor.The precision of the system reaches 4.9 μm,which meets the testing requirement.  
        关键词：Synchrotron radiation;Double crystal monochromator;Invariable relative height;Off-line measurement   
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        发布时间：2021-03-05
      • YU Yingying LI Ming
        Vol. 34, Issue 6, (2011)
        摘要：In an X-ray pinhole imaging system for measuring the source transverse size of synchrotron radiations,scintillators are used to convert X-rays into visible lights that can be received and imaged by CCD.However,the point source projected on the scintillators would be enlarged to a blur,which is the imaging system response to the point source,i.e.point spread function(PSF) of scintillators.PSF is a key factor to the imaging system resolution.By combining the noise deduction of images and the arithmetic average of the edge spread function along the knife edge,we developed a method to determinate PSF of scintillator,and obtained the PSFs(FWHM) of 100 and 200 μm thick LYSO,200 μm thick BaF2 and 3 mm thick CdWO4.The results will be refered in designing the X-ray pinhole imaging system at BSRF.  
        关键词：PSF;Scintillator;X-ray imaging system   
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        发布时间：2021-03-05
      • XU Tao1,2 LUO Liqiang1 1
        Vol. 34, Issue 6, (2011)
        摘要：Elemental mapping of human hair may gain new insights for studying effects of mining environmental pollution on human health.SRXRF micro-analyses were conducted for longitudinal and transversal mapping of Pb,Fe,Cu and Zn relative intensities in hair sample collected from an inhabitant in Qixia lead-zinc mining area,Nanjing,Jiangsu province,China.The Pb relative intensity was low in hair follicle and root,but it increased with the hair growth.The longitudinal Pb accumulation in the hair shaft revealed a strong dependence on continuous exposure to the environment,while Fe,Cu and Zn relative intensities in the hair shaft were comparatively stable.The cortical proteins contributed to a high retention of Pb,Fe,Cu and Zn,while small quantities of all the elements but Zn were distributed in the cuticle.Medullar proteins were confirmed to contribute to slightly lower retention of Zn and Cu than cortical,but Pb and Fe were not detected in medulla.The sources of Pb in the hair were mostly exogenous contamination,and Fe,Cu and Zn were related to endogenous uptake.Zn and Cu participated in the entire metabolic process of hair growth.The study shows that SRXRF is of significance for biogeochemistry research.  
        关键词：SRXRF elemental mapping;Human hair;Lead-zinc mine   
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        发布时间：2021-03-05
      • LI Chenggang DENG Jianjun LI Qin CHEN Nan
        Vol. 34, Issue 6, (2011)
        摘要：An integrative device is designed for diagnosing high-energy X-ray sources.It performs simultaneous measurements of the spot sizes,intensity distributions,bremsstrahlung spectrum,and angle distributions of X-rays at one shot.Spot size and intensity distribution are obtained using the square-hole coded imaging method.Bremsstrahlung spectra are obtained using helix wedge absorption imaging method.And angle distribution of dose is obtained using LiF dose absorber.The device was used at two accelerators,Dragon-I and 12 MeV LIA,at Institute of Fluid Physics,CAEP,for diagnosing X-ray sources.  
        关键词：X-ray source;Energy spectra;Spot size;Intensity distribution;Angle distribution   
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        发布时间：2021-03-05
      • QIN Chao1 WANG Dezhong1 YU Wendan2 ZHANG Kuo1 1
        Vol. 34, Issue 6, (2011)
        摘要：When comparative method is adopted in gamma-ray spectrometry measurements of environmental samples,self-attenuation correction of under test samples is necessary,because of different self-attenuation coefficients of the reference and test samples.In this work,we investigate the self-attenuation correction by finding the relationship between the transmissivity and self-attenuation at the same photo-peak.The parameters of HPGe detector crystal were obtained by point source experiments.Based on these parameters,the relationship between the transmissivity and self-attenuation were studied by using the MCNP code.The differences of density and chemical composition were taken into account.This results show that method can be used to estimate the self-attenuation correction of complicated matrix samples.  
        关键词：Environmental bulk samples;Self-attenuation correction;Transmissivity;Gamma-ray spectrum analysis   
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        发布时间：2021-03-05
      • MU Yanhong FU Pengtao ZHANG Jianhua YANG Chaowen
        Vol. 34, Issue 6, (2011)
        摘要：There are several factors affecting the detection of explosive or landmine using neutron-induced reactions,such as the neutron source,detector,object and surroundings.In this paper,using a system of NaI(Tl) or BGO detectors and an Am-Be neutron source,prompt gamma ray spectra from nuclides in TNT of landmine in soil are simulated by MCNP.The counts of full energy characteristic peaks of gamma rays from hydrogen,carbon,nitrogen and oxygen in TNT are related to the explosive mass.Effects of the soil moisture on the gamma-ray spectrum are studied.The ratio of full energy peak counts from nitrogen to full energy peak counts from carbon is defined.A method to use the ratio to identify explosives under water environment is proposed.  
        关键词：Neutron;Monte Carlo simulation;Explosive;Prompt gamma-ray   
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        发布时间：2021-03-05
      • SUI Li1,2 WANG Xiao1 ZHOU Pingkun2 NI Meinan1 KONG Fuquan1 YANG Lei1 LIU Jiancheng1 ZHAO Kui1 1
        Vol. 34, Issue 6, (2011)
        摘要：The pUC19 plasmid DNA solutions in different DNA concentrations,with or without mannitol,were irradiated by 16 MeV protons to different doses.Changes in the DNA form were observed by means of gel electrophoresis in order to study effects of dose and DNA concentration on yields of DNA strand breaks.The results indicate that the dose and DNA concentration response exist in two solution systems,the forms of DNA changed from intact supercoiled to open circular,in a linear relationship with the dose.The yields of DNA strand breaks in DNA solution without mannitol are much more than that those with mannitol,illuminating that mannitol can scavenge the free radicals and reduce the yields of DNA single and double strand breaks induced by protons efficiently.In addition,the dose effects of DNA damage were investigated at a concentration of 10 or 100 ng/?L.The results show that dilute DNA solution need lower dose than the dense solution in observing similar degree of damage.  
        关键词：Protons;Plasmid DNA;Double strand break;DNA concentration   
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        发布时间：2021-03-05
      • LI Ming1,3 YU Xuefeng1,2 LU Jian1,3 GAO Bo1,3 CUI Jiangwei1,3 ZHOU Dong1,3 XU Fayue1,3 XI Shanbin1,3 WANG Fei1
        Vol. 34, Issue 6, (2011)
        摘要：In this work,PDSOI static random access memory(SRAM) were irradiated under the static bias condition to different total doses,and annealed at 25oC for 36 h and 100oC for 168 h.Changes in the power supply current of the devices,and their functional errors were measured and studied.The total dose radiation damage mechanisms and the correlation between the changes of power supply current and device function are discussed.For the large-scale SOI integrated circuits,this provides the possible ways and methods to further study the total dose radiation hardening and the radiation damage assessment of the satellite devices.  
        关键词：PDSOI;SRAM;Total-dose effects;Power supply current;Annealing effects   
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        发布时间：2021-03-05
      • MA Long1 GAN Zaiguo1 HUANG Minghui1 HUANG Tianheng1 ZHANG Zhiyuan1,2 JIA Guobin1,2 ZHOU Xiaohong1 XU Hushan1 ZHAN Wenlong1 1
        Vol. 34, Issue 6, (2011)
        摘要：A rotating target wheel for targets of low melting point was designed at IMP.Isotopically enriched Pb targets of about 1.5 cm ?6.0 cm and of thicknesses of 0.4–0.6 mg/cm2,covered with thin C layers on both sides,were mounted on the wheel and irradiated by 5.84 MeV/u 24Mg7+ ion beams of up to 1 e?A,and 4.95 MeV/u 0.1 p?A 64Ni19+ ion beams on a beam spot of 0.785 cm2,with a total particle dose on the targets of about 1015.No damage to the targets was observed.  
        关键词：Rotating targets system;Sandwich targets;Beam spot;Beam currents   
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        发布时间：2021-03-05
      • XU Feng WU Xiaoli YUAN Qi MA Yubo
        Vol. 34, Issue 6, (2011)
        摘要：From September 2005 to November 2009,107 cases of keloids were treated by using 90Sr-90Y brachytherapy(25 Gy in 5 daily 5-Gy fractions,for 1–3 courses).No keloids were thicker than 6 mm.Questionnaires were developed to find assessment of the patients 12 months after the treatment.And χ2-test was used to tell the results differences according to the gender and recurrences.The radiation side effects were also recorded.The results showed that 65% patients considered the therapeutic outcome to be excellent or good,and 71% patients considered the cosmetic outcome to be excellent or good.Patients with keloids on ear or perineal were greatly satisfied with the outcome(both the therapeutic and cosmetic outcomes were 100%).The patients’ assessment had no significant difference in gender.And patients without recurrence enjoyed the relief from former keloid-caused symptoms compared to the patients with recurrence(P<0.05).The recurrence rate could be related to the keloid thickness(P<0.05).The recurrence did not have an influence on assessment in cosmetic outcome(P>0.05).The radiation side effects include telangiectasias(24%),hyperpigmentation(43%) and depigmentation(33%),but none of them was wild.No patients were found to get systemic adverse reactions.90Sr-90Y brachytherapy is a good method to treat patients with keloides of less than 6 mm in thickness.The therapeutic and cosmetic outcomes are acceptable,and 90Sr-90Y brachytherapy is a good choose for the patients who cannot tolerate the pain of operations or injections.  
        关键词：Keloids;90Sr-90Y brachytherapy;Therapeutic outcome;Cosmetic outcome;Radiation side effect   
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        发布时间：2021-03-05
      • YANG Yuqing SONG Hu SONG Hongtao PU Manfei
        Vol. 34, Issue 6, (2011)
        摘要：Boron neutron capture therapy(BNCT) applies the high linear energy transfer radiation of α particles and 7Li ions released from the 10B(n,α)7Li reaction in pre-localized boron-containing compounds in tumor tissue.Apparently,there are two prime aspects in BNCT,i.e.the outer neutron flux and boron-containing compound.Boron porphyrins is an important 10B-carrier for BNCT under wide research since 1990’s.This paper begins with the characteristics of BNCT,required properties of 10B-carrier and property of porphyrins,then focuses on the application researches of boron porphyrins from main research institutions in the field in the past two decades.This provides a useful reference for further design of better boron porphyrins.  
        关键词：Boron porphyrins;Boron neutron capture therapy;BNCT   
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        发布时间：2021-03-05
      • BU Jiangtao KUANG Hongbo
        Vol. 34, Issue 6, (2011)
        摘要：The rod control and rod position systems in No.1 reactor of Qinshan nuclear power plant have been remodeled into digitized systems.The digital systems were achieved by PLC logic control functions,and a human-machine interface was used for online monitoring of system status and parameter changes.Redundant configuration was adopted for PLC controller to improve the system flexibility and reliability.The original analog circuits were modified into double-hold circuits against failures.Redundant communication between the rod control and rod position system was used to reduce the numbers of field cable.A data collection cabinet was designed to sample the coil waveform data on the drive mechanism for real-time data acquisition and facilitate post-accident analysis.  
        关键词：Rod control and rod position indication system;Digital controller;Programmable logic controller;Double-hold   
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        发布时间：2021-03-05
      • PENG Tao LI Liang
        Vol. 34, Issue 6, (2011)
        摘要：In this paper,influence of the stainless steel cylinder on the magnetic field is studied by using numerical methods.Simulations show that due to the SS cylinder,the equivalent resistance of the discharge circuit increases and the equivalent inductance reduces,hence a 4.9% reduction of the magnetic peak field and 6.7 reduction of the rise time for a cylinder of 20-mm wall.Experiments were carried out and the results agreed well with the theoretical analysis.  
        关键词：Pulsed magnet;Coil;Magnetic field;Steel cylinder;Eddy current   
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        发布时间：2021-03-05
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