最新刊期
      卷 0 ， 期 0 ， 2020
      • Issue 1, (2007)
        摘要：The BPM system in 100MeV linac includes BPM(Beam position monitor),BPM front-end electronics, BBC module,RF switch module and AD module．The BPM front-end electronics and the detailed design of the data acquisition system are presented in this paper.Then,the testing results for BPM system’s performance in linac operation are introduced.  
        关键词：BPM electronics;BPM system;IOOMeV linac   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：Synchrotron radiation based fluorescent microtomography (SR-XFMT) is a nondestructive technique for detecting elemental composition and distribution inside a specimen with high spatial resolution and sensitivity,and will be an optional experimental technique at SSRF hard X-ray micro-focusing beamline now under construction.In this paper,the principles and developments of SR-XFMT are briefly introduced.Computer simulation of SR-XFMT experiment is performed.The image of the simulated sample is reconstructed using Filtered Back Projection (FBP), Algebraic Reconstruction Techniques(ART) and modified FBP with absorption correction.The qualities of the re-constructed images are analyzed and compared.The validity of these reconstruction techniques is discussed.  
        关键词：X-ray fluorescent microtomography;Computer simulation;Synchrotron radiation;Image reconstruction   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：This study set a target for applying magnetic fluid seals to the turning shaft system.The structure of the first crystal turning shaft system was analyzed,the principle of magnetic fluid seals and the influencing factors were described,and the structure of magnetic fluid seals was determined．The application shows the structure of magnetic fluid seals is simple,zero-leak,and frictionless,which fully meets the operation requirement.  
        关键词：Synchrotron radiation;Double-crystal monochromator;Magnetic fluid seals   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：The Pb slab is often used to protect normal tissues against beam damage in electron beam treatment of sensitive tumors.The spectral characteristics of a 10 MeV clinic electron beam as a function of the depth are simulated using Monte Carlo code MCNP4C.The simulation results show the relationship between the mean beam energy and the ratio of the mean energy of the backscattered spectra to that of the primary spectra.The similar characteristics are obtained for several scattering materials.The variation in the backscattering effect intensity with the depth is also qualitatively analyzed in viewpoint of the energy spectrum,and the consistent conclusions with the published literature are deduced.  
        关键词：Monte Carlo simulation;Clinic electron beam;Electron backscattering effect;Spectral characteristics;Mean beam energy   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：The Scanning Proton Microprobe(SPM)facility was improved by using a new designed scanning coil system.A pair of saddle-shape air core coil Was designed,and the coils Can be controlled by a remote controlling system.The performance of SPM was tested by a sample(nickel net).The results show that the system has the scanning area of 760μm×900μm for a 3 MeV proton beam.The lateral resolution was 0.9μm×l.0μm at 10 pA beam current.Individual aerosol particles and tetrahymenas were studied by the facility.The elemental distributions in these samples were obtained.  
        关键词：Scanning proton microscope;Scan coil;Resolution   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：Combining the modified external-beam proton induced X-ray emission(PIXE),inductively coupled plasma atomic emission spectrometry(ICP-AES)and other techniques,the chemical compositions,structures and other properties of some ancient glass samples of the Han Dynasty,which were unearthed from Hepu county, Guangxi,were determined.These glass samples can be classified to several glass systems,such as K2O-Si02, PbO-BaO-Si02,PbO-Si02,Na2O-K20-PbO-Si02 and (Na20)K20-CaO-Si02.But most of the samples belong to K20-Si02system glass.Due to the surface corrosion,the flux K20 in the surface of the K20-Si02glass Was lost,but with the relative enrichment of the Si02.Based on the characteristics of chemical composition and appearance of these samples,it is thought that,during the Han Dynasty,the making technique of the K20-Si02 glass in China Was influenced by the technique related to the PbO-BaO-Si02 glass from abroad.  
        关键词：PIXE;Ancient glass;Chemical composition;Hepu county   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：Two kinds of operational amplifiers LM118J-8 and OP07,and a reference device 7F3140,were irradiated with 60Coγrays and their radiation responses were measured in situ simultaneously.The results show that the output voltages of OP07 amplifier changed obviously at 100 Gy(Si),while LMll8J-8’s did not change obviously until 900 Gy(Si).It is shown that LMll8J-8 amplifier has better radiation tolerance than 0P07,and that their different radiation tolerances result from different configurations and technologies of circuits.The invalidity and degradation of LMll8J-8 and 0P07 amplifier can be attributed to theγ-radiation-induced interface states.  
        关键词：Operational amplifier;γ-radiation;Radiation effects   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：Radiation effects of 1 MeV electron on a home-made type of tripie-junction GaInP/GaAs/Ge solar cell have been investigated.The results indicate that the GalnP/GaAs/Ge solar cell has high efficiency and high radiation hardness.The final-to-initial maximum power ratio (P/P0) of the GaInP/GaAs/Ge cell was 80.4% at a fluence of l×l0(15)cm(-2).The spectral response of the GalnP top subcell showed little degradation,and this was not a limitation for GalnP/GaAsd/Ge cell performance.The GaAs middle subcell I(sc),however,presented serious degradation.The degradation of GalnP/GaAs/Ge solar cell is due primarily to the GaAs middle subcell.  
        关键词：Multiple-junction solar cell;GalnP／GaAs／Ge;Electron irradiation;Radiation effect;Spectral response   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：By introducing the alignment of two heavy scientific projects in China,we discuss the common features of survey technology in heavy facilities for physics experiments.Effective surveying methods with high precision are presented.  
        关键词：Precision;Network;Frame;Accelerator;Laser tracker   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：By using the relative measurement method,the number of 10B nuclei in the thin film sample was measured.The experiment was performed at the 4.5 MV Van de Graaff accelerator of Peking University.Neutrons were produced through the D(d,n)reaction and the fast neutrons were moderated by the thick paraffine layer.A 6LiF sample with definite number of 6Li nuclei was used as thereference,and a twin gridded ionization chamber was used to detect the tritons from the 6Li(nth,t)4 He reaction and the alpha particles from the 10B(nth,α)7 Li reaction.  
        关键词：Thin film sample;10B nuclei;Gridded ionization chamber   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：The carbon stripping foils Can be prepared with the AC and DC arc discharge methods,or even sandwiched with AC-DC alternative layers.The lifetime of the carbon stripping foils of 19μg/cm2 prepared with different methods and/or structures was measured.The factors affecting the bombarding lifetime of the carbon stripping foils,especially the method of the foil preparation and the structure of the carbon stripping foils,were discussed.It is observed that the foils prepared with the DC arc discharge method have a longer bombarding lifetime than those prepared with the AC arc discharge method.  
        关键词：Carbon stripping foil;Bombarding lifetime;AC／DC arc discharge method   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：This paper describes the preparation ofβ-elemene derivative of Re(C0)3 and[188Re]-1abelled radioactiveβ-elemene derivative of Re(CO)3.β-elemene derivative was synthesized by purifiedβ-elemene with di-(2-picoyl)amine.Radioactiveβ-elemene derivative of Re(CO)3 was synthesized byβ-elemene di-(2-picoyl)amine with fac-[188Re(CO)3(H20)3]+ and purified by C18 reverse phase HPLC.β-elemene derivative was synthesized at a yield of 64%.Radioactiveβ-elemene derivative of Re(CO)3 was prepared with a radiochemical yield of 40% and a radiochemical purity of greater than 95%.It is concluded that this process is economic and suited for preparing ra-dioactiveβ-elemene derivative of Re(CO)3 which may become a potential therapeutic radiopharmaceuticals in the fu-ture.  
        关键词：β-elemene derivatives;Di-(2-picoyl)amine;Rhenium-tricarbonyl;Radiolabeling   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：The purpose of this study was to evaluate 99mTc-SC dynamic imaging for diagnosis of chyluria.Forty-one nake eye chyluria patients who went through cystoscopy were observed.Age ranged from 16-65 a(average 41.7 a).Thirty-three were males and eight females.Bilaterial injection of 3.7×108Bq 99tc-SC was made subcutanously into the inter-toe web,and dynamic imaging was carried out using VG Hawkeye SPECT(GE)．Classification of the imaging:(a)bilateral chyluria kidney:bilateral kidney or renal pelvis was imaged in early dynamic imaging;and(b)unilateral chyluria kidney,which Can be divided into three types:(1)unilateral kidney was imaged in early imaging;(2)only unilateral renal pelvis was shown in early imaging;(3)iliae lymph vessels showed enlargement rapidly on the diseased side.Since 99mTc-SC dynamic imaging is higher sensitive and non-invasive in the diagnosis of chyluria,it is a great help to differential diagnosis for bilateral chyluria kidney or unilateral chyluria kidney,and according to the classification of unilateral chyluria kidney imagings the degree of chyluria can be evaluated.  
        关键词：Chyluria;99mTc-SC imaging;Lymphoscintigraphy   
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        发布时间：2021-03-12
      • CHENG Xu,LIDianfu,HUANG Gang,XU Zhaoqiang,TAG Ruqi,FENG Jianlin,LI Jianhua
        Issue 1, (2007)
        摘要：To investigate the value of assessing viable myocardium by wall thickening(WT)coming from 99mTC-MIBI ECG-gated myocardial perfusion imaging(G-MPI)in myocardial infarction,twenty-six patients with myocardial infarction underwent rest 99mTc-MIBI G-MPI,EKG,18F-FDG myocardial metabolic imaging and CAG within two weeks.For determining viable myocardium,the segments of myocardium with abnormal MIBI uptake and normal wall thickening(WT)were 68.2% of ischemic viable myocardium demonstrated by 99mTc-MIBI/18F-FDG dual isotope tomography.The segments of myocardium with abnormal MIBI uptake and abnormal WT were 96.8% of infarct myocardium demonstrated by dual isotope tomography．Use of wall thickening coming from 99mTc-MIBI G-MPI may help to select more viable myocardium as compared with conventional myocardial perfusion imaging.  
        关键词：Tomography;Single-photon;Coronary artery disease;Cell survival;MIBI   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：To assess the diagnostic value of standard uptake values(SUVs)in lung lesions and to explore the optimal threshold,the biological influencing factors for SUV in lung cancer were researched.84 patients,all of whom had lung lesions,experienced PET-CT scanning(malignant lesions 59,benign lesions 30,respectively)．Every lung lesion was measured by the technique of region of interest(ROI),and each lesion’S maximal SUV(SUVmax) and average SUV(SUVave)values were recorded.The diagnostic efficiencies of SUVmax and SUVave were compared and the optimal threshold was established according to the analysis of the ROC curve.The relationships between SUVave and pathologic type and tumor size were analyzed through the analysis of correlation and variance with covariates.There is no significant difference between the areas under curves of SUVmax(O.8975)and SUVave(O.8966),so the diagnostic values of these two methods for lung lesions are similar.When SUVmax>5.2 or SUVave>4.4 was taken as the cut-off value,the diagnostic accuracy was the highest,and the sensitivity,specificity and accuracy is 89.8%,80.O%,86.5%,respectively.Squamous cell carcinoma had higher SUV(8.5±2.9)and bigger tumor size(4.I±I.5 cm)than adenocarcinoma(5.3±2.2,2.5±1.0 cm)(P<O.05).There is a significant positive correlation between tumor size and SUV either in squmnous cell carcinoma or in adenocareinoma(P<0.05).After eliminating the influence of tumor size,SUV of squamous cell carcinoma(7.2±0.5)is still higher than that of adenocarcinoma(6.1±0.4),but there is no statistic significance(P>0.05).It is concluded that SUV is useful for differentiating lung lesions.When SUVmax>5.2 or SUVave>4.4 is taken as the cut-off value,the diagnostic accuracy is highest．The SUV of lung cancer is more likely influenced by tumor size than by pathologic type.  
        关键词：Positron emission tomography;Standard uptake value;Lung cancer   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：A terminal synchronizer in Inertial Confinement Fusion(ICF) is introduced in this paper. It has medium time resolution and is based on the VXI bus system standard. Via VXI bus, a computer can control pulse-width, amplitude and time delay of its output pulse. The electronic test has presented that its inherent time delay is less than 30 ns, the front edge time of its output pulse is less than 14 ns and the time jitter is less than 5 ns. The test results prove that the synchronizer can be used in ICF experiment.  
        关键词：Computer-controlled synchronizer;VXI bus;Field programmable gate array;Inertial confinement fusion   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：The amplitude calibration of an electric field sensor is important in the measurement of electromagnetic pulse.In this paper,an arbitrary waveform generator(AWG)is used to generate multi-waveform electric field in the TEM cell and the dipole antenna pulsed electric field sensor is calibrated.In the frequency band of the sensor,the calibrated amplitude coefficients with different waveforms are identical.The coefficient derived from the TEM cell calibration system suits to the measurement of unknown electric field pulse within the frequency band.  
        关键词：Pulsed electric field sensor;Amplitude calibration;Arbitrary waveform generator;High electromagnetic pulse   
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        发布时间：2021-03-12
      • Issue 1, (2007)
        摘要：In this paper the neural network is used to identify reactivity.The identification result can be compared with those using other methods to reduce the start-up risk.The first order gradient optimization algorithm is employed to train the network．The training samples stem from the neutron kinetics of the point-reactor.The character of neutron multiplication is analyzed.Simulation results indicate that being capable of effectively identifying reactivity,the neural network method is worth spreading.  
        关键词：Nuclear reactor;Physics start-up;Reactivity;Neural network;Identification   
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        发布时间：2021-03-12
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