最新刊期
      卷 0 ， 期 0 ， 2020
      • WU Yuedong ZHAO Ziqiang
        Vol. 34, Issue 1, (2011)
        摘要：Self-assembled silica PC (photonic crystals) were bombarded by 6 MeV Au ions to different doses at LN temperature. Reflection spectra of the irradiated PC exhibited the following transformations: the centre of reflection band shifted toward short wavelength, and the bandwidth was broadened. Moreover, the shift and broadening of reflection band increased with the dose. By fitting- analysis of the spectra, combining the SEM imaging, we came up with an explanation, which attributes optical transformations of PC to the structural changes induced by ion irradiation. This work could be of help for modifying the PC structure to achieve specific optical properties.  
          
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        发布时间：2021-03-05
      • WANG Huihui HAO Shengzhi HE Dongyun XU Yang ZHANG Xiangdong
        Vol. 34, Issue 1, (2011)
        摘要：High current pulsed electron beam (HCPEB) is an efficient way for materials surface modification. In this paper, we report microhardness distribution of HCPEB-treated metallic materials, including D2 mold steel, Fe-40Al intermetallic and Mg alloys. The extreme temperature and stress fields induced by HCPEB could change the mechanical property in the surface layer and depths beyond that heat-affected zone, hence the property modification of increased depths. The HCPEB treatment could be applied in surface hardening.  
        关键词：High current pulsed electron beam (HCPEB);Surface treatment;Metallic materials;Microhardness CLC TG17   
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        发布时间：2021-03-05
      • ZHANG Wenfeng CAO Hui HAO Yi GAO Bo TU Ganfeng
        Vol. 34, Issue 1, (2011)
        摘要：ZK60 Mg alloy was treated by high current pulsed electron beam (HCPEB) so as to improve the wear resistance. Surface SEM images show that the HCPEB bombardment caused surface melting, grain boundary elimination and uniform distribution of the metal compositions. SEM image of the cross-section microstructure indicates that a remelted layer of 5–11 μm was formed on surface of the HCPEB-treated ZK60 Mg alloy. Wear test shows that wear resistance of the treated ZK60 Mg alloy after 23 keV 15-pulse treatment was improved by a factor of 2.5.  
        关键词：Mg alloy;HCPEB;Microstructure;Wear resistance   
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        发布时间：2021-03-05
      • YU Xiaojuan WU Xunlei JIANG Zhenbo MENG Mingfeng
        Vol. 34, Issue 1, (2011)
        摘要：In this paper, an electron gun for a linac E-beam irradiator is developed with a replaceable cathode and filament. The structure of cathode and filament and the concentric technique, with molds and clamps, are described in detail. The electron gun was assembled with care to reduce the error, and ensure the concentricity of electron gun. The test results indicated a 99.99% pass ratio of the electron beams at 60–65 kV. The electron gun design meets the technical requirement of clients.  
        关键词：Electron gun;Cathode and filament;Molds and clamps   
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        发布时间：2021-03-05
      • XIE Zhiwen WANG Langping WANG Xiaofeng YAN Jiuchun HUANG Lei LU Yang
        Vol. 34, Issue 1, (2011)
        摘要：A new multiple-cathodes metal plasma source was designed. The plasma uniformity, duct bias voltage and current of the magnetic coils were studied and optimized. TiAlSiN composite coating was prepared on this equipment. The chemical composition, microstructure and mechanical properties of the coating were investigated by utilizing energy dispersive X-ray (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nano- indentation measurement. The results revealed that the equipment can be used for preparing composite coating. TiAlSiN coating showed n-TiAlN/a-Si3N4 composite structure. In addition, the film showed high hardness (≥35 GPa).  
        关键词：Multiple-cathodes plasma source;Uniform;Composite coating;Hardness   
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        发布时间：2021-03-05
      • ZHANG Xiangdong1,2 HAO Shengzhi1 Thierry Grosdidier2 DONG Chuang1 1
        Vol. 34, Issue 1, (2011)
        摘要：In this paper,we demonstrate the microstructure modification in the surface layer and the improvement in corrosion resistance and microhardness for pure Ti samples treated by high current pulsed electron beam(HCPEB).With increasing number of pulses,the treated surfaces became relatively flatter.Multi-layer structure containing amorphous layer and nano-crystalline layer in the near surface of the treated pure Ti samples was also examined.Microhardness of the treated samples was increased from the initial 178 Hv to 292 Hv.According to the potentiodynamic polarization curves,the treated samples exhibited improved corrosion resistance in 5% NaCl solution compared with the virgin.Of all the samples,the 15-pulse treated sample is of the best corrosion resistance with the corrosion current increased from the initial –346.4 mV to –188.9 mV.The defects such as high dislocation density as well as the formation of amorphous and nano-crystalline layers induced by the HCPEB treatment were believed to be reasons for the improvements in corrosion resistance and microhardness.  
        关键词：High current pulsed electron beam(HCPEB);Pure Ti;Surface treatment;Corrosion resistance;Microhardness CLC   
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        发布时间：2021-03-05
      • XIAO Kunxiang JIN Dazhi XIANG Wei TAN Xiaohua
        Vol. 34, Issue 1, (2011)
        摘要：The basic principle and method of neutron detection of possible explosives are introduced in this paper. A neutron generator, sized at Φ76 mm×1100 mm, is designed at CIAP. For installing an α particle detector in the generator, the Penning ion source is applied with high voltage and the target is grounded. In order to improve the detector efficiency, the ion beam incidence to the target is 45°. The test results show that the generator has good stabilization, and generator has been used for over 100 hours in the neutron output from 3×107 to 5×107 n/s.  
        关键词：Neutron generator;Explosive;Concomitant particle   
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        发布时间：2021-03-05
      • ZHOU Ruijie HU Liqun LU Hongwei LIN Shiyao ZHONG Guoqiang XU Ping ZHANG Jizong
        Vol. 34, Issue 1, (2011)
        摘要：For suppressing the energy of runaway electrons in tokamak plasma, we analyzed the X-ray energy spectra by runaway electrons in different discharges of the HT-7 tokamak experiment performed in the autumn of 2009. The resonant phenomenon between runaway electrons and magnetic ripple was found. Although, the energy of runaway electrons in the plasma core can be as high as several tens of MeV, but when they are transported to the edge, the electron energy are limited to a certain range by resonance with the magnetic ripple of different harmonic numbers. The runaway electrons under high loop voltage resonate with low step magnetic perturbations, with high energy gain; whereas the runaway electrons under low loop voltage resonate with high level magnetic perturbations, with low energy gain. Using this mechanism, the energy of runaway electrons can be restricted to a low level, and this will significantly mitigate the damage effect on the equipment caused by runaway electrons.  
        关键词：Runaway electron;Magnetic ripple;Resonant   
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        发布时间：2021-03-05
      • WANG Zhenxia1 WANG Tianzhe2 XIE Yanxiang3 HE Zhiyong1 TANG Bin1 1
        Vol. 34, Issue 1, (2011)
        摘要：Nb alloyed layer was prepared by plasma surface alloying technology on surface of stainless steel substrates.Microstructure morphology,depth profiling of the elemental composition and phase structure of the alloyed layer were analyzed.Corrosion performance of the Nb alloyed layer was investigated.The results show that the optimum parameters were: temperature,1100oC;air pressure,80 Pa,holding time 3 h,source voltage,900–700 V;and cathode voltage,600–450 V.The thickness of Nb alloyed layer was about 60 μm.The alloyed layer was mainly composed of NbC and Nb6C5,Cr2Nb and Fe2Nb.The surface Nb content was 50%,which decreased sharply in the first several microns of depths and then gradually in further depths.The Nb alloyed layer has improved resistance to intergranular corrosion and uniform corrosion.  
          
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        发布时间：2021-03-05
      • LI Gang SHUI Dongli TANG Haipeng CHEN Yongjun LIU Li HOU Junying
        Vol. 34, Issue 1, (2011)
        摘要：In this work,eutectic Al/Cu powder was used to prepare Al/Cu alloys by SHS-sintering(laser-induced self-propagating high-temperature synthesis).Influences of the pressing pressure,laser power and sintering time on microstructure of the sintering alloys,densification and hardness were studied by SEM,OM,XRD and Brinell′s Hardness Tester.It was found that uniformity and relative density of the sintering alloy increased with the laser power and sintering time.When the relative density of the original compacts was 85%,the sintered density could be up to 3.11 g/cm3;the highest hardness of sintered alloy was 131HB and this was at the central area.In order to estimate the sintering cooling rate of the location,the measure of secondary dendrite arm spacing is proposed.  
        关键词：Laser induced;Microstructure;Densification;Hardness;Secondary dendrite arm spacing   
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        发布时间：2021-03-05
      • TAN Jun XING Ruxin QIAN Yaochuan
        Vol. 34, Issue 1, (2011)
        摘要：To improve contact resistance and corrosion resistance of the bipole in proton exchange membrane fuel cells (PEMFC), chromium nitride films were deposited on 304 stainless steel by magnetron sputtering. Effects of the target current on morphology and phase of the CrxN coatings were investigated. The contact resistance and corrosion resistance of the coatings was tested. The results show that the contact resistance between the modified 304 stainless steel and Toray carbon films is 22.65–24 m?/cm2, within the package force of PEMFC. In the simulative environment of PEMFC (0.05 mol/L H2SO4 + 2 mg/L F– on 80oC), the corrosion current of modified bipolar plates is 0.5×10–6 A/cm2. Increasing the target current can improve the properties of anti-corrosion and conductive on metal bipolar plates.  
        关键词：PEMFC metal bipolar plates;Surface modification;Magnetron sputtering   
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        发布时间：2021-03-05
      • ZHAO Chengli1,2 SUN Weizhong3 Lü Xiaodan1 CHEN Feng1 HE Pingni1 LIU Huamin3 ZHANG Junyuan3 GOU Fujun3,4 1
        Vol. 34, Issue 1, (2011)
        摘要：In this study,molecular dynamics simulation method was used to investigate the interactions of 10 eV F ions continuously bombarding SiC surface with incident angles of 15?,30?,45?,60? and 75?.The simulation results show that the deposition rate of F decreases with increasing incident angle.It is found that when the incident angle is 45?,the etching rates of Si and C atoms reach the maximum values.The etching rate of Si atoms is greater than that of C atoms.A Si-C-F reactive layer is formed after the F ions interaction with SiC surface.The thickness of Si-C-F layer decreases with increasing incident angle,and the formation of Si-C-F layer are primarily SiF and CF.  
        关键词：Molecular dynamics;Incident angle;Etching;Si-C-F layer   
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        发布时间：2021-03-05
      • WU Xunlei YU Xiaojuan JIANG Zhenbai
        Vol. 34, Issue 1, (2011)
        摘要：A new type of electron guns has been developed for a 10 MeV 1.5 mA linac for radiation processing. The specifications required are: cathode voltage 60 kV, peak beam current 550–600 mA, spot size 4 mm, and working distance 60 mm. Particularly, this electron gun is advantageous in its replaceable cathode-heater assembly. This helps the customers to reduce their operation cost. The Egun and Mafia codes were used to simulate electromagnetic fields and electron trajectories. The guns were produced in the same technology of our klystron production. Design specifications of the gun were achieved in the beam current test and beam spot test. The first gun of this type has been working on an linac for about 3000 hours.  
        关键词：Electron gun;Replaceable cathode;Replaceable heater;Beam spot measurement;E-beam irradiator   
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        发布时间：2021-03-05
      • CHEN Wenhao CHEN Min XIAO Tiqiao
        Vol. 34, Issue 1, (2011)
        摘要：Effects of the incident angle offset on FT-IR spectra are investigated in this paper.The simulated FT-IR spectra are obtained by Fourier inverse transform.The results show that this frequency shift varies with the angle offset of the incident beam in FT-IR.As an example,the factors that affect the angle of incident IR light at SSRF are analyzed.According to performance specifications of the IR beamline,requirements of the optical component installation precision and position drift of the light source are given.  
        关键词：Interferometer;Optical path difference;Incident angle offset;Synchrotron radiation   
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        发布时间：2021-03-05
      • ZENG Jianrong1,2 BAO Liangman1 LONG Shilei1,2 LU Wenzhong1 TAN Mingguang1 LIN Jun1 LIU Wei1 ZHANG Guiling1 LI Yan1 MA Chenyan3 ZHENG Lei3 HAN Yong3 ZHAO Yidong3 1
        Vol. 34, Issue 1, (2011)
        摘要：ynchrotron radiation X-ray absorption near-edge structure(XANES) spectroscopy is a powerful method for nondestructive quantitative determination of elemental speciation.Sulfur K-edge XANES spectroscopy has been successfully used to characterize sulfur species in atmospheric particulate matter(PM).We tried to analyze the concentration of sulfur in PM using XANES combined with ion chromatography(IC).Different sulfur states and their percentage to total sulfur element in PM were conformed by analyzing the sulfur K-edge XANES spectra.The sulfur concentration under different states was obtained using the sulfur concentration in soluble SO42? divided by the percentage of +6 sulfur in PM.The XANES and IC analyses of atmospheric PM2.5 collected at five coastal sites in Shanghai revealed that sulfates(about 90%) was the dominating sulfur compound in the samples,while a few sulfonates(4.8%–6.5%) and di-and polysulfides(0%–6.8%) were detected.The concentration of total sulfur in the atmospheric PM2.5 is 3.60–6.38 μg.m?3.  
        关键词：XANES;IC;Atmospheric particles;Speciation;Sulfur concentration   
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        发布时间：2021-03-05
      • ZHANG Zhongjian1 SUN Yelei1 LI Gongping1 LIU Qin2 1
        Vol. 34, Issue 1, (2011)
        摘要：Because of the unique geographic environment and climatic conditions in Lanzhou in northwest China,and its long-time petrochemical and metallurgical industrial activities,it has become a seriously air-polluted city,especially in winter.Winter aerosol samples were collected in four urban areas in Lanzhou and Yuzhong County(located in outskirts of Lanzhou).Their TSP contents were measured,and heavy metal elemental concentrations were analyzed by PIXE analysis.The results were discussed.  
        关键词：Total suspended particulates;Heavy metal element;PIXE CLC X831   
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        发布时间：2021-03-05
      • HUANG Weihsing WU Rayshyan CHENG Yukuan
        Vol. 34, Issue 1, (2011)
        摘要：In the dry storage of spent nuclear fuels,concrete cask serves both as a shielding and a structural containment.The concrete in the storage facility is expected to endure the decay heat of the spent nuclear fuel during its service life.Thus,effects of the sustaining high temperature on concrete material need be evaluated for safety of the dry storage facility.In this paper,we report an experimental program aimed at investigating possible high temperature effects on properties of concrete,with emphasis on the mechanical stability,porosity,and crack-resisting ability of concrete mixes prepared using various amounts of Portland cement,fly ash,and blast furnace slag.The experimental results obtained from concrete specimens exposed to a temperature of 94oC for 90 days indicate that:(1) compressive strength of the concrete remains practically unchanged;(2) the ultrasonic pulse velocity,and dynamic modulus of elasticity of the concrete decrease in early stage of the high-temperature exposure,and gradually become stable with continuing exposure;(3) shrinkage of concrete mixes exhibits an increase in early stage of the exposure and does not decrease further with time;(4) concrete mixes containing pozzolanic materials,including fly ash and blast furnace slag,show better temperature-resisting characteristics than those using only Portland cement.  
        关键词：Dry storage of spent nuclear fuel;Concrete degradation;Non-destructive testing;High temperature   
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        发布时间：2021-03-05
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