最新刊期
      卷 0 ， 期 0 ， 2020
      • CHANG Rui1,2 TAI Renzhong1 David E.Starr3 Hendrik Bluhm4 LIU Zhi2 1
        Vol. 35, Issue 7, (2012)
        摘要：In this paper,the development of synchrotron radiation-based ambient pressure photoelectron spectroscopy(APXPS) is reviewed.The principle and technology of APXPS is given,and applications of APXPS are discussed.It is demonstrated that APXPS technology fills the gap between ultrahigh vacuum and the pressure under real conditions,and has great advantage in the in-situ study of surface chemistry dynamics;catalytic reactions;corrosion and electrochemical process.  
        关键词：Ambient pressure photoelectron spectroscopy(APXPS);Catalytic reaction;Electrochemical   
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        发布时间：2021-03-05
      • LI Xudong1,2 CHEN Liping1 GU Qiang1 LIN Guoqiang1 ZHAO Minghua1 1
        Vol. 35, Issue 7, (2012)
        摘要：A bialkali antimonide photocathode is of high quantum efficiency(QE) for visible lights,low emittance,and relatively long life time in the strong RF field and practical vacuum.It produces high-brightness electron beams to meet the energy recovery need of a linac.This kind of photocathode contains cesium,hence the need of preparing,transferring and operating it in ultra high vacuum(UHV).In this paper,we report the design of a bialkali antimonide photocathode preparation apparatus developed at SINAP.Functions of the equipment are described.The UHV pumping,the photocathode substrate cleaning and preparation the K-Cs-Sb photocathode are presented in detail.The QE is measured under different laser power densities and wavelengths.Other testing experiments for performance of the K-Cs-Sb photocathode prepared with this apparatus are conceived.  
        关键词：Photocathode;Quantum efficiency(QE);Ultra high vacuum(UHV);Preparation apparatus   
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        发布时间：2021-03-05
      • WEI Huifang 1,2 WANG Bing 2 GAO Di 1,2 GUAN Ming 1 CHEN Hanqing 2 JIANG Jing 2 QU Xiuyun 2 ZHENG Lingna 2 OUYANG Hong 2 FENG Weiyue 2 1
        Vol. 35, Issue 7, (2012)
        摘要：upermagnetic iron oxide nanoparticles(Fe3O4-NPs) can promote many attractive functions in biomedical fields.In this study,the interaction of Fe3O4NPs(10 nm and 40 nm) with cytochrome c(Cyt c) was studied by synchrotron radiation circular dichroism(SRCD) and UV-Vis spectroscopy.After adding Fe3O4NPs in the Cyt c solution,the intensity of the Soret band(408 nm) decreased significantly.The SRCD characterization showed the loss of the α-helix structure and the occurrence of cytochrome c unfolding after Fe3O4-NPs treatment,meanwhile,the 10 nm Fe3O4-NPs had more prominent effects than the 40 nm ones.The results showed significant size-depended and dose-depended effects.This study provides important insight into the interaction of Fe3O4NPs with cytochrome c,which may be a useful guideline for further use of Fe3O4NPs.  
        关键词：Fe3O4nanoparticles;Cytochrome c;SRCD   
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        发布时间：2021-03-05
      • LI Bo WU Congfeng LIANG Minqiang
        Vol. 35, Issue 7, (2012)
        摘要：In order to understand breakdown characteristic of the photonic band-gap(PBG) structures working at high power and high repetition rate,the PBG accelerator structure is simulated and analyzed at X band(11.424 GHz) in this paper.The results show that the E/H value of the PBG accelerating structure with ronnd metallic inner rods is at 240,and its T value is at 300 K.By replacing the ronnd inner rods with oval-shaped metal rods,the peak E/H value increases by 140 and the T value decreases by 150 K.The electromagnetic field of a new quasi-PBG accelerating structure is simulated,too,with the Q value of over 10000 and E/H = 570.Because of the inner Al2O3 ceramic rods,it is a structure of high gradient acceleration.  
        关键词：Photonic crystals;Magnetic effect;High Q value;HOMs   
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        发布时间：2021-03-05
      • ZHANG Junqiang1,2 YIN Chongxian1 GAO Yongqiang YU Luyang1 ZHAO Minghua1 ZHONG Shaopeng1 1
        Vol. 35, Issue 7, (2012)
        摘要：To satisfy the Top-up operation mode of Shanghai Synchrotron Radiation Facility(SSRF),and ensure the linac to provide stable and high current beam bunches,a low level radio frequency(LLRF) control system was developed for sub-harmonic buncher.Based on field programmable gate array(FPGA),LLRF realized digital amplitude and phase feedback control by using up-down converter,IQ modulator and demodulator techniques.Digital principles and application programs were introduced,and table test was performed.The LLRF system achieved an amplitude control accuracy rate of 1 % and phase control accuracy of 1,well meeting the design requirement.  
        关键词：FPGA;LLRF;Sub-harmonic buncher;Amplitude and phase control   
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        发布时间：2021-03-05
      • ZHANG Yanwen1 LIU Shiyi1 WANG Xu1 WANG Cheng1 ZHAO Ziqiang1 QIAN Xi2 LI Ting2 LU Daogang2 1
        Vol. 35, Issue 7, (2012)
        摘要：In this work,12Cr-ODS steel samples were irradiated by different combinations of Si,He and H ion beams at room temperature.Mechanical property measurements of the irradiated samples showed that all the samples exhibited irradiation swelling and hardening,but the sample co-irradiated by three ion beams had the biggest swelling and smallest hardening.Combining on the TEM imaging,analyses of irradiation changes of 12Cr-ODS steel samples were carried out.Raman spectra of the irradiated samples revealed carbon precipitated inside the samples,and carbon peak distribution could reflect the radiation damage distribution.The results,which accumulated experimental data and clarified the radiation damage to nuclear materials by synergy effect,are of help for application of 12Cr-ODS steel in an advanced reactor.  
        关键词：12Cr-ODS steel;Multi-ion-beam irradiation;Synergy effect;Irradiation damage   
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        发布时间：2021-03-05
      • LI Gang1 ZHAO Yunlong1 HAO Shengzhi2 1
        Vol. 35, Issue 7, (2012)
        摘要：LY12 aluminum alloy samples were modified by 3–25 times of high current pulse electron beam(HCPEB) treatment at 23.4 or 27 kV.The number of melting craters in the irradiated sample surface decreased with increasing number of the pulses,and the crater size increased with the pulse number.XRD analysis of the virgin sample showed the major phase of-Al and the secondary phases of CuMgAl2and CuAl2,which disappeared partly in XRD patterns of the samples treated with the HCPEB of certain pulses.The microstructure refinement and preferred orientation of crystal planes could be observed in the HCPEB treated samples,and the surface micro-hardness increased to a maximum in certain depths,where it began to decrease because of reduced energy deposition in greater depths.Test results showed that the irradiated samples exhibited a remarkable property enhancement against electrochemical corrosion,with the corrosion potential increased from 0.63 V to 0.52 V and the corrosion current decreased by 2 orders of magnitude.  
        关键词：HCPEB;LY12;Microstructure;Micro-hardness;Electrochemical behavior   
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        发布时间：2021-03-05
      • YE Jianfeng1 PEI Yuanji2 1
        Vol. 35, Issue 7, (2012)
        摘要：In this work,electron beam degradation of carboxymethyl cellulose(CMC) in solid state was investigated.The results showed that viscosity of the irradiated CMC in 2% aqueous solution decreased with increasing doses.FT-IR characterization of the CMC samples before and after irradiation showed that the irradiation of 40 kGy can lead to rapid breaking off of the glucoside bond(C1-O-C4).The irradiation degradation of CMC in solid state obeys the rule of random degradation.  
        关键词：Carboxymethyl cellulose(CMC);Electron beam irradiation;Viscosity   
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        发布时间：2021-03-05
      • WU Yang TANG Bin HUO Heyong LIU bin
        Vol. 35, Issue 7, (2012)
        摘要：Fast neutron radiography(FNR) is an attractive non-destructive inspection technique in terms of the excellent penetration characteristics of fast neutrons in matter.FNR can be the only approach for non-destructive inspection of industrial products which are too thick or too dense for thermal neutron radiography.The imaging plate detector,a two dimensional detector for ionizing radiations,can be over 100 times more sensitive than conventional radiography films.At Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,an FNR system based on D-T accelerator neutron source has been established,with a spatial resolution of 1 mm.In this paper,we report its detector structure and the laboratorial test results.  
        关键词：Fast neutron radiography;Imaging plate   
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        发布时间：2021-03-05
      • LIU Hui 1 JIN chufeng 1 GE Shenfang 3 WU Lijun 2 WU Yican 1 FDS Team 1
        Vol. 35, Issue 7, (2012)
        摘要：In this work,we investigated the bystander effect of the tumor and normal cells surrounding the target region caused by radiation-inducible target gene therapy combined with α-particle irradiation.The receptor tumor cell A549 and normal cell MRC-5 were co-cultured with the donor cells irradiated to 0.5 Gy or the non-irradiated donor cells,and their survival and apoptosis fractions were evaluated.The results showed that the combined treatment of Ad-ET and particle irradiation could induce synergistic antitumor effect on A549 tumor cell,and the survival fraction of receptor cells co-cultured with the irradiated cells decreased by 6%,compared with receptor cells co-cultured with non-irradiated cells,and the apoptosis fraction increased in the same circumstance,but no difference was observed with the normal cells.This study demonstrates that Ad-ET combined with α-particle irradiation can significantly cause the bystander effect on neighboring tumor cells by inhibiting cell growth and inducing apoptosis,without obvious toxicity to normal cells.This suggests that combining radiation-inducible TRAIL gene therapy and irradiation may improve tumor treatment efficacy by specifically targeting tumor cells and even involving the neighboring tumor cells.  
        关键词：Gene therapy;α-particle irradiation;Combination treatment;Bystander effect;Apoptosis   
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        发布时间：2021-03-05
      • ZHANG Changfan GONG Jian LIU Suping HU Guangchun XIANG Yongchun
        Vol. 35, Issue 7, (2012)
        摘要：Template measurement for plutonium pit extracts characteristic data from-ray spectrum and the neutron counts emitted by plutonium.The characteristic data of the suspicious object are compared with data of the declared plutonium pit to verify if they are of the same type.In this paper,neural networks are enhanced as the comparison algorithm for template measurement of plutonium pit.Two kinds of neural networks are created,i.e.the BP and LVQ neural networks.They are applied in different aspects for the template measurement and identification.BP neural network is used for classification for different types of plutonium pits,which is often used for management of nuclear materials.LVQ neural network is used for comparison of inspected objects to the declared one,which is usually applied in the field of nuclear disarmament and verification.  
        关键词：Plutonium pit;Template measurement;Neural network;Characteristic data   
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        发布时间：2021-03-05
      • LI Jian WANG Hong SONG Jianming LIU Lijuan SUN Guangai
        Vol. 35, Issue 7, (2012)
        摘要：The static shielding of Residual Stress Neutron Diffractometer(RSND) is mainly used to protect the workers against-rays and neutrons from the reactor.The static shielding is mainly around the additional shutter and the neutron guide system.For providing ensured safety for personnel in the experiments area,calculations of the shielding system were carried out using the MCNP5 code.The shielding design can be optimized based on the calculation results.  
          
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        发布时间：2021-03-05
      • LI Jianbo1,2 SHEN Hua1 NIU Tingting3 ZHANG Xiaohui1,2 QI Yujin1 ZHANG Lan1 1
        Vol. 35, Issue 7, (2012)
        摘要：CA IX(carbonic anhydrase IX),which is highly overexpressed in several solid tumors with limited distribution in normal tissues,is a drug target in the diagnosis and treatment of tumors.In this work,anti-carbonic anhydrase IX(CA IX) monoclonal antibody(MAb) was labeled with 99Tcm.Under the optimized conditions,the labeling yield and the radiochemical purity of 99Tcm-MAb were 85%.99Tcm-MAb was stable in NBCS and PBS.99Tcm-MAb was injected into tail vein of three nude mice bearing HT-29 tumor for planar imaging.The radioactivity was not observed in the tumor 24 h post injection(p.i.).Biodistribution at 24 h p.i.in the mice showed a little uptake of99Tcm-MAb in tumors.The planar imaging with125I-MAb at 48 h p.i.showed high concentration of radioactivity in the tumor.Because of slow metabolic cycle of Ab in the body and the short half-life of 99Tcm,99Tcm-MAb is not suitable for tumor imaging for targeting CA IX.  
        关键词：99Tcm;Carbonic anhydrase IX;Monoclonal antibody;Planar imaging   
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        发布时间：2021-03-05
      • WANG Dingding 1,2 WU Jie 1,2 ZHANG Jie 1,2 HAN Zhao 1,2 LIU Liefeng 1
        Vol. 35, Issue 7, (2012)
        摘要：CompactRIO is widely used in all kinds of embedded control and detection system,but it has no high precision and high integration acquisition module.In order to meet the requirements of high precision sampling applications,we designed a high precision data acquisition module with self-calibration based on CompactRIO.This module is highly integrated.Being of an area of 73.38 mm × 66.04 mm,it realizes 6-channel data acquisition of 24 bit,with the THD of better than –108 dB,and RMS noise of below 1.2 μV.The module can achieve offset calibration and gain calibration of ADC according to an internal high precision voltage source,which improves the amplitude consistency among channels.Test results demonstrate that self-calibration improves the amplitude consistency from 1.5% to 5× 10 6.  
        关键词：CompactRIO;High precision data acquisition;Offset calibration;Gain calibration;Amplitude consistency   
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        发布时间：2021-03-05
      • WANG Liwei GU Ming YUAN Qibing
        Vol. 35, Issue 7, (2012)
        摘要：In this paper,we report the design of data acquisition(DAQ) and processing(DSP) system for feedback control of a linac modulator to improve amplitude stability of its output HV pulse.Hardware and software requirements for the system are analyzed to achieve the required stability,and relevant experimental results are given..The DAQ system consists of stratix ii FPGA board,AD6645 and upper PC.The measurement resolution is improved by use of differential amplifier.DSP algorithm takes sample mean value as pulse amplitude.Methods of average,interpolation,digital filtering,BP Neural Network etc.are practiced to improve monitor resolution and anti-jamming capacity.  
          
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        发布时间：2021-03-05
      • WANG Zhuo GE Liangquan ZHANG Qingxian XU Lipeng LUO Yaoyao
        Vol. 35, Issue 7, (2012)
        摘要：X-ray fluorescence analysis is widely used in field survey and laboratory analysis.Background of a characteristic X-ray peak must be subtracted for determining the elemental content.In this paper,the method of Fourier transform background subtraction is used.It is less affected by changes in the background than linear background subtraction.The result shows that using FFT background subtraction of XRF spectra collected in a field survey,the Sr contents are 11.0% less in average than those obtained in laboratory XRF analysis of the samples,whereas using linear background subtraction,the average error is –25.9%.  
          
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        发布时间：2021-03-05
      • LIU Jingsong LIU Jianhua ZHANG Yingying WU Zhongliang TAN Juhua LIN Dongdong ZHOU Xingfei
        Vol. 35, Issue 7, (2012)
        摘要：Recent studies show that many neuropathies such as Alzheimer’s disease are associated with the aggregation in vivo of amyloid-like protein.While the aggregation progress depends on sequences of the amino acids,also it is closely related to the environmental factors such as metal ions,pH,temperature etc.In this paper,effect of Fe3+ ions on the aggregation is investigated by atomic force microscopy and micro-FTIR.The results show that the lag time of fibrillation is dramatically extended,and the second structure of formed fibrils changes,too,in glucagon mixed with Fe3+ions.It also suggests that such a change may depend on concentration of added Fe3+ions.  
        关键词：Glucagon;Fe3+ions;Aggregation;AFM;Micro-FTIR   
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        发布时间：2021-03-05
      • LI Ye ZHANG Dong WANG Ping LI Taowen SUN Yu ZHAO Dan TAN Zhaoyi
        Vol. 35, Issue 7, (2012)
        摘要：In this work,decontamination of painting on metal surface by dry ice jet was carried out.The influence of jet parameters on decontamination efficiency was examined.The results showed that the painting weight loss decreased with increasing speed of jet movement.The optimized parameters were target distance of 25 mm,jet angle of 63°,and the pressure of 0.6 –0.7 MPa,with a filtration efficiency of over 99% and 5.8–9.0 μm particle sizes of the aerosol.For the painted samples polluted by 137Cs and 235U,the decontamination effect is excellent.For the polluted plumbum kettles,this method is effective.Therefore,the dry ice jet is an excellent technology for painting on metal surface.  
        关键词：Dry ice;Decontamination;Coat;Aerosol   
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        发布时间：2021-03-05
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