最新刊期
      卷 0 ， 期 0 ， 2020
      • LI Jiudong DENG Huiyu
        Vol. 34, Issue 10, (2011)
        摘要：The full text retrieval system of SSRF-PDM is a database-based retrieval system,but it had deficiencies in recall ratio,precision ration and relevancy ranking.To improve the system performance,the Chinese word segmentation algorithm and detailing relevancy ranking algorithm were optimized.Test results show that recall ratio and precision ratio can be improved to meet the data management needs of SSRF.  
        关键词：PDM;Full text retrieval;Chinese word segmentation;Relevancy ranking   
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        发布时间：2021-03-05
      • WU Tianding 1 HU Jianzhong 1 ZENG Lei 1 PENG Guanyun3 LU Hongbin2 1
        Vol. 34, Issue 10, (2011)
        摘要：Three male SD rats were subjected to angiography via ascending aorta with silicone rubber for investigating rat spinal cord microvasculature images by using synchrotron radiation-based micro-computed tomography.Low thoracic cord was harvested,followed by X-ray radiography,synchrotron radiation micro-imaging and thick histological section in situ.The microvascular images were clearly projected by synchrotron radiation.The rendered 3D images produced more details of the microvascular arrangement in rat spinal cord harmonized with histology.It is of great potential to investigate microvessel-related spinal cord disease with synchrotron radiation-based micro-computed tomography.  
        关键词：Synchrotron radiation;Computed tomography(CT);Microvasculature;Spinal cord;Morphology   
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        发布时间：2021-03-05
      • FAN Xuebo1,2 LIN Jun1 LIU Wei1 WANG Guanghua1 YAO Jian1 ZENG Youshi1 HUANG Yu1,3 ZHAO Yidong4 GUO Zhi1 LI Yan1 1
        Vol. 34, Issue 10, (2011)
        摘要：Carbon chemical species in size-resolved airborne particulate matters collected on January 14 and October 16–17,2010 at SINAP,a suburban spot in northwest Shanghai,and in three standard samples(oxalic acid,sucrose and graphite),were characterized on October 19–21,2010 with the near-edge X-ray absorption fine structure(NEXAFS) spectroscopy.The C(1s) NEXAFS spectra differ distinctly among the freshly collected particulate matters of different size ranges and different collection hours,i.e.in day time or at night.The difference is mainly the asymmetrical distribution of carboxyl-COOH,carbonate and carbonyl C = O components.However,this was not observed among the C(1s) NEXAFS spectra of particulate matters collected in different hours of January 14 and kept refrigerated for 9 months,suggesting possible decay or re-equilibrium of the carbon chemical species in the sample storage.  
        关键词：Airborne particles;Carbon functional groups;NEXAFS;Size distribution   
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        发布时间：2021-03-05
      • AN Pengfei QIU Nan ZHANG Jing ZHENG Lirong HU Tiandou XIE Yaning
        Vol. 34, Issue 10, (2011)
        摘要：In this paper,a new liquid sample device for XAS measurement is reported.It is well sealed and can be conveniently disassembled,cleaned and re-assembled,facilitating XAS measurements of various kinds of aqueous solution and organic solvent samples.A temperature control device can be added to the sample cell for temperature-dependent XAS measurement.With a pump connecting to nanoparticle liquid synthesis or catalysis reaction systems,real time XAS measurement can be performed with the new device.  
        关键词：Synchrotron radiation;XAS measurement;Liquid sample cell   
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        发布时间：2021-03-05
      • LIU Chunbao1,2 ZHAO Zhiming3 WANG Zhiguang2 1
        Vol. 34, Issue 10, (2011)
        摘要：Amorphous SiO2 films of about 1 ?m in thickness were thermally grown on single crystalline silicon.The samples were implanted at room temperature(RT) with 120 keV C ions to doses ranging from 1.0 ? 1016 to 8.6 ? 1017 ions/cm2,and then irradiated at RT with 950 MeV Pb ions to 5.0? 1011,1.0 ? 1012 and 3.8 ? 1012 ions/cm2,respectively.Photoluminescence(PL) properties of the samples were investigated using a fluorescent spectroscopy at RT.The results show that Pb ion irradiation affected significantly the PL properties,which depended strongly on doses of the C ion implantation and Pb ion irradiation.For example,huge PL peaks at about 2.89 eV and 2.53 eV could be seen in PL spectra of the sample implanted with 5.0 ? 1011 C ions/cm2 and irradiated by 3.8 ? 1012 Pb ions/cm2.This suggests that micro-structure like 6H-SiC may be induced in the C ion-implanted and Pb ion-bombarded a-SiO2 films.It seems that special light emitters can be produced by combined ion implantation and irradiation,which is a useful way for synthesizing new type of SiO2-based light-emitting materials.  
        关键词：Photoluminescence;Heavy ion irradiation;Ion implantation   
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        发布时间：2021-03-05
      • SONG Le1 HAN Rongfei2 XU Xue1 LIU Binmei1 XU Hongqing3 ZHANG Ying4 WU Yuejin1 1
        Vol. 34, Issue 10, (2011)
        摘要：To explore mechanism for the effect of saddle-like dose-response curve,the relationship of irradiation-vacuum stress,and irradiation-salt stress,was investigated with rice seeds irradiated to 60–560 Gy by 60Co γ-rays.The dose-response curve was simulated based on seedling height data,which showed obedient to linear-quadratic model.During germination,the irradiated rice seeds were stressed by 10–3 Pa vacuum,or by NaCl in different concentrations.After that,the dose-response curve manifested a saddle-like shape.The results indicate that while low dose irradiation could retard seedling growth synergistically with vacuum stress and salt stress,it could also induce adaptive response upon vacuum stress and salt stress.Low dose irradiation induced adaptive response upon environmental adverse factors could contribute to the mechanism for the effect of saddle-like dose-response curve.  
        关键词：Radiation;Saddle-like dose-response curve;Linear-quadratic model;Adaptive response;Environmental stress   
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        发布时间：2021-03-05
      • WANG Xinhua ZHENG Pu LIU Rong YANG Xiaofei YANG Jian
        Vol. 34, Issue 10, (2011)
        摘要：A simulation blanket assembly consisting of depleted uranium and LiH is established for studies on fusion-fission hybrid energy reactor.The leakage neutron spectra from a directly current D-T neutron source placed in the blanket assembly were measured by BC501A spectrometer in the 0.75–16 MeV energy range.The measured leakage neutron spectra were compared with the results calculated by the 3D Monte Carlo code MCNP5 and continue energy cross sections from the ENDF/B-VI data file.The comparison shows that the MCNP5 code with appropriate data library can reasonably approximate the measured leakage spectra of neutrons.  
        关键词：DU/LiH assembly;DT neutron;Leakage neutron spectra   
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        发布时间：2021-03-05
      • WU Yang DOU Haifeng TANG Bin HUO Heyong
        Vol. 34, Issue 10, (2011)
        摘要：For designing a minitype neutron radiography system,which is advantageous in detecting large or irremovable objects.a shielding collimator was simulated with the MCNP code.U-238 and high density polyethylene were chosen to moderate 14 MeV neutrons to 3 MeV.Graphite and CH-B were used as reflect layer and shielding layer,respectively.With the optimized design parameters,as the results show,the neutron radiography system can provide a neutron flux of up to 104 cm?2.s?1,with L/D = 30,imaging area = 20 cm×20 cm,and Cd radio = 20.  
        关键词：Minitype neutron source;Thermal neutron;Digital radiography;Design   
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        发布时间：2021-03-05
      • WU Jianhui LI Gongping ZHOU Long PAN Xiaodong LIN Qiaolu
        Vol. 34, Issue 10, (2011)
        摘要：Cone beam computed tomography(CT) based on flat detector has interested many CT researchers.Different CT scanning modes have different effect on ART image reconstruction.In this paper,using a 128 ? 128 ?128 3D Shepp-Logan head model as the object of simulation,impacts on image reconstruction are studied with different geometries of the radiation source,scanning center and detectors;different number of projections;and different scanning modes under fixed projections.An object to which scans cannot be done at certain angles is investigated,too.The following results are obtained.The image reconstruction is better when the source-center and the center-detector distances are in a certain proportion.Under fixed projections,the reconstructed image quality is better with a uniform 180o scan.To obtain a better image reconstruction in occasions where some angles are unable to scan,the projections should fill the first interval angle range uniformly with the angle interval 1°–2°,and the remaining projections should fill the second interval angle range uniformly.  
        关键词：Cone beam CT;Scanning mode;ART algorithm;3D Shepp-Logan head model;Quality of reconstructed image   
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        发布时间：2021-03-05
      • TANG Ganghua
        Vol. 34, Issue 10, (2011)
        摘要：Multi-target molecular imaging(MMI) is an important field of research in molecular imaging.It includes multi-tracer multi-target molecular imaging(MTMI),fusion-molecule multi-target imaging(FMMI),coupling-molecule multi-target imaging(CMMI),and multi-target multifunctional molecular imaging(MMMI).In this paper,imaging modes of MMI are reviewed,and potential applications of positron emission tomography MMI in near future are discussed.  
        关键词：Single-target molecular imaging;Multi-target molecular imaging;Multi-target molecular probe;Coupling-small molecule imaging;Multi-modality molecular imaging;PET   
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        发布时间：2021-03-05
      • JIN Chufeng1,3 LIU Hui2,3 ZHENG Huaqing2,3 CHENG Mengyun2,3 LI Gui2,3 SUN Guangyao1,3 WU Yican1,3 FDS Team 1
        Vol. 34, Issue 10, (2011)
        摘要：Estimates of second primary cancers risk after radiotherapy has become increasingly important for comparative treatment planning.A new method based on the treatment planning system to estimate the risk of second primary cancers was introduced in this paper.Using the Advanced/Accurate Radiotherapy Treatment System(ARTS),a treatment planning system developed by the FDS team,the risk of second primary cancer was estimated over two treatment plans for a patient with pancreatic cancer.Based on the second primary cancer risk,the two plans were compared.It was found that,kidney and gall-bladder had higher risk to develop second primary cancer.A better plan was chosen by the analysis of second primary cancer risk.The results showed that this risk estimation method we developed could be used to evaluate treatment plans.  
        关键词：Second primary cancer;Risk prediction;Radiotherapy;Plan evaluation;ARTS   
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        发布时间：2021-03-05
      • WANG Ying JIN Yaoge SHI Xueying GAO Yong
        Vol. 34, Issue 10, (2011)
        摘要：To investigate clinical value of glomerular filtration rate(GFR) and urine microalbumin in early diagnosis of diabetic nephropathy,GFR in 60 patients with type Ⅱ diabetes mellitus and a control group of 20 were determined using 99TcmDTPA renal dynamic imaging and urine microalbumin.The following results were obtained.Among the 60 patients with diabetes,5 patients had increased GFRs of,142.0? 13.6mg/min,which was 35% higher than that of controls and differed significantly from the control(P? 0.01);20 patients had GFRs of 102.2? 10.2mg/min,which differed little from the control;and 35 patients had declined GFRs of 57.2±18.0mg/min,which was 54.3% lowered than the control and differed significantly from the control(P<0.01).The urine microalbumin in diabetes patients was significantly higher than the control.In conclusion,the GFR is a good index of the early kidney injury in diabetic patients.The combined detection of GFR and urine microalbumin can improve the early diagnosis of diabetic nephropathy,and may help to monitor the treatment response and assess prognosis.  
        关键词：Type 2 diabetes;Diabetic nephropathy;Glomerular filtration rate;Urine microalbumin   
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        发布时间：2021-03-05
      • YANG Qiang LAI Wanchang HUA Yongtao GE Liangquan WANG Guangxi
        Vol. 34, Issue 10, (2011)
        摘要：A multi-purpose handheld radionuclide detection instrument has been developed,with an ARM7-based multi-channel analyzer,and optional detectors of CdTe or NaI(Tl) scintillator.Having a data base of common natural and artificial radioactive nuclides,it can realize in-situ field measurements and radionuclide detection.Testing results show that energy resolutions of CdTe detectors achieves 800 eV@59.54 keV(241Am) and 5.9 keV@0.662 keV(137Cs),which are good enough for detecting nuclides of medium-low-energy γ-rays,while the NaI(Tl) detector can be used to detect nuclides of high-energy γ-rays.  
        关键词：Radionuclide detection;Nuclear instrument;ARM7;CdTe detector   
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        发布时间：2021-03-05
      • JIANG Shilun QI Jiangmin ZHOU Lin
        Vol. 34, Issue 10, (2011)
        摘要：The magnetic proton recoil technology is a new diagnostic instrument for fusion neutron spectrometry studies.It has good energy resolution and high signal-to-noise ratio,and is suitable for measurements in mixed fields and large dynamic neutron flux environments.In this paper,we give a review on the magnetic proton recoil spectrometers developed at the world’s large fusion facilities,where good results in different fusion experiments have been obtained.They include the magnetic proton recoil spectrometer(MPR) at Joint European Torus(JET),using the magnetic analysis system of two-pole electromagnet and achieving an energy resolution of 2.5%;and the magnetic recoil spectrometer(MRS) at OMEGA,University of Rochester,USA,where the magnetic analysis system is capable of analyzing 6–32 MeV protons and an energy resolution of 3.0% has been achieved.A magnetic proton recoil spectrometer developed at China Academy of Engineering Physics using a 0.79 T permanent magnet,with an efficiency of up to 6.2 ? 10–6 cm2 and an energy resolution of 1.6%–2.1%.  
        关键词：Recoil proton;Magnetic analysis;Fusion neutron diagnostic   
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        发布时间：2021-03-05
      • GAO Wei ZHANG Qinfang
        Vol. 34, Issue 10, (2011)
        摘要：In this paper,binary decision diagram(BDD) algorithm is used for fault tree analysis.The ways of calculating failure probability and minimal cut-set(MCS) for certain fault trees are presented,including conversion from fault tree to BDD structure,obtaining MCS from BDD,MCS storage in terms of zero-suppressed BDD(ZBDD) for space-saving,and calculation of top event unavailability.A program was compiled and validated by calculating a PSA model of certain nuclear power plant both by hand and RiskSpectrum PSA.The comparison results show that the program can qualify and quantify a fault tree of relatively small scale.  
        关键词：Fault tree analysis;Binary decision diagram(BDD);Program compiling   
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        发布时间：2021-03-05
      • DONG Lan JANG Shubin CHENG Qiong DU Yang YANG Yong MA Junge
        Vol. 34, Issue 10, (2011)
        摘要：The geometric structures and electronic property of the clusters Wn(n=2–5) and W-Mo were investigated by using(GGA)PW91/DNP based on density functional theory(DFT).H2 adsorption of W clusters was studied.Mulliken charge population analysis before and after H2 adsorption on W4 and W2Mo2 clusters was calculated.The results show that Wn(n=2–5) clusters are covalence.Adsorption energy range is from 0.02068 to 1.9552 eV.Fukui indices show that activated energy can be reduced if W and Mo are in proper proportion.Mulliken charge population analysis shows that W-Mo clusters adsorb H2 unsteadily.  
        关键词：Wn(n=2–5) clusters;W-Mo clusters;Density functional theory(DFT);Adsorption   
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        发布时间：2021-03-05
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