最新刊期
      卷 0 ， 期 0 ， 2020
      • XIE Guoxi1,2 FENG Songlin1 FENG Xiangqian1 WANG Yanqing1 ZHU Jihao1 LI Yongqiang3 HAN Hongye3 1
        Issue 4, (2007)
        摘要：In order to determine the provenance of two different kinds of ancient celadons which were excavated in Maojiawan ruin located in Beijing of China and named FLQ(imitated celadon) and WLNQ which is celadon outside and blue-white inside,ten components of each sample’s body and glaze were measured by the wave length dispersive X-ray fluorescence(WDXRF) analysis. Multivariates statistical analysis was used to analyze and compare the experiment data with those of LQY(ancient celadon) made in Zhejiang and ancient Jingdezhen porcelain(JDZ) made in Jingdezhen. The results show that the two different kinds of ancient celadons have the same provenance as JDZ,that is,they were produced in Jingdezhen.  
        关键词：Ancient porcelain;Provenance research;WDXRF   
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        发布时间：2021-03-12
      • WANG Baoyi CAO Xingzhong WEI Cunfeng ZHANG Zhiming MA Chuangxin ZHANG Tianbao WEI Long
        Issue 4, (2007)
        摘要：A slow positron beam-line based on the 1.3 GeV linac of Beijing Electron Positron Collider(BEPC) has been constructed to produce intense slow positron beam. The produced positron beam is pulsed corresponding to the linac pulse of 2.5 ns pulse width and 12.5 repetition rate. In this paper,a self-designed Pilot U scintillation detector for measuring the beam intensity of pulsed positron and positron energy spread is introduced. By using this developed technique,we have quantitatively determined the positron amount by an oscilloscope to read the height of dynode pulse and the integral voltage of PMT anode,respectively. It is much convenient to place the detector outside vacuum and even to find the beam position when adjusting the transportation of pulsed positron beam.  
        关键词：Slow positron beam;Linac;Beam intensity;Integral voltage;Pilot U scintillation detector   
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        发布时间：2021-03-12
      • SUI Li1 GUO Jiyu1 KONG Fuquan1 NI Meinan1 CAI Minghui1,2 YANG Mingjian1,2 LIU Jiancheng1 ZHAO Kui1,3 1
        Issue 4, (2007)
        摘要：In order to investigate the direct and indirect interaction of DNA damage induced by high LET heavy ions as well as the protective function of scavenger by means of atomic force microscopy,samples of pUC19 plasmid DNA aqueous solution,pUC19 plasmid DNA aqueous solution with scavenger(mannitol) and dry DNA are irradiated by 7Li ions from the HI-13 Tandem accelerator in China Institute of Atomic Energy(CIAE). Results show that the indirect interaction of free radical plays an important role in DNA strand break induced by 7Li ions and mannitol can protect the DNA molecules effectively.  
        关键词：Linear energy transfer;Heavy ions;Plasmid DNA;Atomic force microscopy;Double strand breakage;Free radical scavenger   
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        发布时间：2021-03-12
      • YANG Mingjian1,2 KONG Fuquan1 ZHAN Yong2 WANG Xiao1 NI Meinan1 SUI Li1 CAI Minghui1,2 ZHAO Kui1,3 1
        Issue 4, (2007)
        摘要：To evaluate the effect of free radicals on DNA damage induced by heavy ions,pUC19 plasmid DNA solution with different kinds of scavengers(Mannitol,Vitamin C and Tea Polyphenols) is irradiated by γ rays. The DNA damages are analysed by gel electrophoresis and Alpha Innotech digital imaging system. The results show that all of the three kinds of scavengers can significantly protect DNA;mannitol is more effective than Vitamin C under the same condition;and their capacity of scavenging free radicals induced by γ rays is more remarkable than those induced by heavy ions.  
        关键词：Free radicals;Scavengers;Mannitol;Vitamin C;Tea polyphenols;γ rays;Plasmid DNA;Gel electrophoresis   
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        发布时间：2021-03-12
      • LIU Yunhong1,2 WANG Rong1,3 SUN Xufang1
        Issue 4, (2007)
        摘要：For simulating space environmental radiation a 2×1.7 MV tandem accelerator was used. GaAs/Ge solar cells were irradiated using 2 MeV C ions with the fluence from 3.1×109 to 6.9×1012 cm-2. Both I-V characteristics and spectral response were measured before and after irradiation. The results show that the Isc,Voc and Pmax of GaAs/Ge solar cells decrease as the irradiation fluence increases,and among them,Pmax decreases the most while Voc the least. This degradation rule is similar to that induced by proton irradiation. But to make Pmax of GaAs/Ge solar cells decrease to 50%,the required irradiation fluence of C ion is less than that of proton with the same range by two orders of magnitude. The spectral response of GaAs/Ge solar cells decreases more significantly in the long wavelength region than in the short wavelength region after C ion irradiation at a low fluence of 3.1×109 cm-2. When the fluence increases to more than 3.1×1010 cm-2,the spectral response in the whole wavelength region significantly degrades. As the fluence reaches to 2.3×1011 cm-2,the spectral response disappears.  
        关键词：GaAs/Ge;Solar cells;Carbon ions;Irradiation   
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        发布时间：2021-03-12
      • ZHANG Wenzhong1 GUO Yong2 LUO Yisheng2 1
        Issue 4, (2007)
        摘要：To research the micro-specialty of proton energy deposition in body-tissue or tissue equivalent material,water vapor was considered to be reasonable as the tissue equivalent material on the basis of analysis of the body-tissue,and Monte Carlo method was used to simulate the behavior of proton in the tissue equivalent material. Some features about the micro-specialty of proton energy deposition in tissue equivalent material were given through the analysis of data from the calculation. Proton will give energy to the electrons along its track in tissue equivalent material,and energy of these electrons will give out in the end. All these energy deposition events made up the proton track in tissue material.  
        关键词：Proton;Secondary electrons;Monte Carlo method;Energy deposition;Position-distribution   
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        发布时间：2021-03-12
      • PEI Yuyang ZOU Yubin GUO Zhiyu TANG Guoyou XU Jianguo GUO Jimei ZHANG Guohui GUO Li’an
        Issue 4, (2007)
        摘要：The accelerator neutron source is more flexible than the reactor neutron source. A neutron radiography facility based on a high current RFQ accelerator is under development at Peking University. For the better design of this system and realization of the small convenient accelerator neutron radiography facility in the future,the installation of neutron radiography was built on the 4.5 MV Van de Graaff at Peking University including the cooled-CCD radiography system to simulate the condition of the RFQ source. The research was carried out on this system using the D-Be reaction. The quality photos of thermal neutron and fast neutron radiography have been obtained when thermal neutron’s flux is 5×103 cm-2·s-1 or fast neutron’s flux is 3.7×104 cm-2·s-1. When using the RFQ accelerator,the better photos can be obtained.  
        关键词：Neutron radiography;Accelerator neutron source;Thermal neutron;Fast neutron;D-Be reaction   
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        发布时间：2021-03-12
      • LIU Changlong1,2 WANG Zhuo1 YIN Lijun1 Lü Yiying1 ZHANG Xiaodong1 1
        Issue 4, (2007)
        摘要：Crystalline Si samples were implanted at room temperature with 40 keV He ions at a dose of 5×1016 cm-2,and then subjected to thermal annealing at different temperatures. Various techniques,such as transmission electron microscopy(TEM),thermal desorption spectroscopy(THDS) and photoluminescence(PL),have been used to investigate damage creation,helium release,luminescence properties and their thermal evolutions. Our results clearly show that He ion implantation followed by annealing induces formation of a well-defined band of cavities. Helium thermal release occurs in two distinguished temperature regions,which correspond to helium release from smaller vacancy-like defects and cavities,respectively. Moreover,He ion implantation can also induce luminescence centers in silicon,which gives rise to photoluminescence bands centered at wavelengths of about 680 nm and 930 nm,respectively. The PL bands may be associated with the formation of silicon nano-clusters produced by the He ion implantation and subsequent thermal annealing.  
        关键词：Crystalline silicon;He ion implantation;Cavities;Helium release;Photoluminescence   
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        发布时间：2021-03-12
      • HUO Heyong TANG Bin WU Yang XUE Bin
        Issue 4, (2007)
        摘要：A quantitative analysis method of neutron radiography is introduced in the paper. The principle of this method is described,and the influence of scattered neutrons on neutron radiography is analyzed using the particle transport programme MCNP. The relationship between the specimen-detector distance and scattered neutrons is also discussed. To weaken the influence of scattered neutrons,the penetrating thickness of thermal neutrons is quantitatively scaled by analyzing neutron pictures in which internal scattered neutrons have trailed off.  
        关键词：Neutron radiography;∑-scaling;Macroscopic cross-section;MCNP programme   
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        发布时间：2021-03-12
      • CHEN Wei LI Rundong ZHU Shilei WANG Yun,YANG Rui
        Issue 4, (2007)
        摘要：The fission isotope target tube was irradiated in a special fuel element of SPRR-300. A positioner for the irradiation assembly was made to practise putting,fetching,and locating the tube,and fixing the electric thermo-couples lead wires,and so on. The axial distribution of neutron fluence rate,the neutron fluence rates at the water gap,and outer and inner walls of the tube were measured. After the reactiveness of the tube was obtained,temperatures at the walls of the tube and at water of the reactor pool were measured at five power steps. The thermal neutron fluence subsidence factor measured is basically in conformity with the self-shield factor deduced from the report of the producer of the tube. By comparing temperatures measured of the outer wall of the tube with those calculated,it is thought that the thermo physical parameters given by the tube’s producer are accurate.  
        关键词：Fission isotope target tube;SPRR-300;Irradiation   
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        发布时间：2021-03-12
      • XIE Chaomei1 LIU Lijuan1 LIU Yanhong1 PENG Mei1 LI Xinxi1 A Boulkin2 V Oulianov2 JIANG Li1 TANG Bin1 1
        Issue 4, (2007)
        摘要：The article introduces the basic principle of the vertically focused monochromator used in neutron scattering spectrometer which has been installed in Institute of Nucleus Physics and Chemistry as well as the adjustment method of the monochromator. The central position and dimension of neutron beam were determined by using neutron radiography,and the available area of the beam was obtained by scanning the sample position along horizontal and vertical directions. The biggest nutron fluence was measured at the sample position. The measured neutron fluence rate data show that almost double gain was got at the sample position.  
        关键词：Neutron diffractometer;Vertically focused monochromator;Adjustment method   
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        发布时间：2021-03-12
      • SUN Guang’ai CHEN Bo
        Issue 4, (2007)
        摘要：Neutron diffraction,an important non-destructive testing method,can facilitate 3-D mapping of residual stress in a bulk component. In this paper,the principle,characteristic and developed status are described about the analysis of residual stress by neutron diffraction. The application of the technique in engineering and material science research is also briefly introduced.  
        关键词：Neutron diffraction;Residual stress   
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        发布时间：2021-03-12
      • WU Yang TANG Bin HUO Heyong DAI Junlong
        Issue 4, (2007)
        摘要：Phase contrast imaging which is based on the wave character of neutron beam,is an advanced technique in neutron imaging field. When we investigate the neutron phase contrast,a simulation is necessary. But so far no software can provide the function to simulate neutron wave. In the paper,we discuss the feasibility of simulating neutron phase contrast imaging process by ZEMAX,a sophisticated optics simulation software. The influences of sample-source distance,sample-detector distance,point neutron source size and sample size on imaging are investigated. The result of the simulation accords with the phase contrast theory,which indicates that ZEMAX is feasible to simulate neutron phase contrast imaging.  
        关键词：Phase contrast;Neutron radiography;ZEMAX;Simulation   
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        发布时间：2021-03-12
      • XIA Xiulong
        Issue 4, (2007)
        摘要：A dynamic theoretical simulation model was built to study cryogenic distillation separation of hydrogen isotopes. Dynamic behavior of DT concentration was obtained. The effects on separation performance of parameters such as reboiler holdup and reflux ratio were studied. The result indicates that the increase of reflux ratio brings about a substantial improvement of the system detritiation efficiency. DT concentration in reboiler is related with time and reboiler holdup,and dynamic calculation shows that DT concentration in reboiler increases almost linearly with time under the proposed operation mode in this paper. The separation performance is satisfactory with 80 stages as the DT concentration in reboiler is enriched 1000-fold compared with that in condenser.  
        关键词：Hydrogen isotopes;Cryogenic distillation;Tritium   
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        发布时间：2021-03-12
      • HUANG Yanjun LI Shuzhen CHEN Nan XIA Yuanfu
        Issue 4, (2007)
        摘要：The pseudobinary alloy Hf0.82Ta0.18Fe2 was prepared by arc melting and annealing technique. X-ray powder diffraction indicated a C14-type Laves phase structure with the crystal parameters a = 4.92133(3) and c = 8.0488(1). The Mssbauer spectra were measured at different temperatures between 20 K and 380 K,and showed two magnetic phase transitions,one from paramagnetic state to antiferromagnetic state at about 330 K and the other from antiferromagnetic state to ferromagnetic state at about 180 K. The latter transition indicated a spin-reorientation for 6h site Fe atoms,thus,the Fe atom spin at 6h turn to ab plane from c axis. However,the Fe atoms at 2a also showed a magnetic moment in ferromagnetic state.  
        关键词：Hf0.82Ta0.18Fe2;Mssbauer Spectrum;spin-reorientation;Magnetic structure   
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        发布时间：2021-03-12
      • LI Shuzhen1 LI Zhen2 HUANG Yanjun1 YI Lin2 XIA Yuanfu1 1
        Issue 4, (2007)
        摘要：In this paper,Mssbauer spectra were used to research thermal decomposing process and the occupation of Fe ions in iron rich palygorskite,which is collected from Longwangshan,Xuyi,Jiangsu Province. It is indicated that Fe ions are in ferric and occupy both M1 and M2 of octahedral ribbon with a ratio close to 3:1.  
        关键词：Palygorskite;Mssbauer Spectrum;occupation   
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        发布时间：2021-03-12
      • FANG Meihua WEI Zhiyong CHEN Da
        Issue 4, (2007)
        摘要：Space radiation is composed of many kinds of energetic particles,in which alpha particle is an important part. So,materials should be studied to protect from this kind of particles for deep space exploration. In this paper,using Monte Carlo method we have simulated high-energy alpha particles’ interaction with different materials like aluminum,polyethylene,water,and liquid hydrogen. Aluminum is not the best material to protect astronauts from space radiation according to the production of secondaries and the relation between projectile energy and range. And Bragg peak comes out at the end of the trajectory.  
        关键词：Geaut4;Alpha particles;Secondaries;Range-energy relationship   
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        发布时间：2021-03-12
      • JIA Wenbao1,2 XU Aiguo1 CHEN Xiaowen1 WANG Huidong1 1
        Issue 4, (2007)
        摘要：In this paper,with the special program of MCNP(Monte Carlo N-Particle Transport code),before and after changing of Ti and Si contents,we have calculated the neutrom field in coal formed by the 14 MeV pulse neutron source. Increasing the content of Ti can obviosly change the neutron field,however,the change is unconspicuous for Si. The imitated experiments validate the analysis conclusion.  
        关键词：Pulse neutron;Coal;Prompt γ spectrum;MCNP;Neutron field   
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        发布时间：2021-03-12
      • ZHOU Lihong1,2 ZHANG Chonghong1 YANG Yitao1,2 SONG Yin1 YAO Cunfeng1,2 1
        Issue 4, (2007)
        摘要：The 4H-SiC specimens were implanted with 110keV C-ions and then irradiated with 230MeV Pb-ions and subsequently annealed at different temperatures in vacuum. The samples were investigated after each annealing stage by using FTIR and Raman spectroscopy. The obtained FTIR spectra showed several interference fringes in the range from 960 cm-1 to 1450 cm-1. The intensity of fringes decreases with the increase of annealing temperature,and an abrupt decrease of the fringe intensity was found for annealing above 900oC,indicating that there was a significant recovery of the irradiation-induced damage in the crystal for annealing at high temperatures. The Raman spectroscopy showed that after annealing at 1200 ℃ for 30 min the amorphous layer was recovered and the precipitation of carbon atoms in graphite occurred.  
        关键词：Ion implantation;Irradiation;4H-SiC;FTIR;Raman spectra;Annealing   
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        发布时间：2021-03-12
      • YANG Yitao1,2 ZHANG Chonghong1 SUN Youmei1 YAO Cunfeng1,2 ZHAO Zhiming1 1
        Issue 4, (2007)
        摘要：Damage induced in the lattice of GaN epi-layers by the bombardment with slow highly-charged heavy ions(SHCI) of Xe26 + extracted from an ECR ion source was measured by RBS/C technique. Behavior of damage accumulation in two geometries(along the normal incidence and the incidence along 60° from specimen’s normal) as a function of ion fluence was studied. The results were discussed in light of the “Coulomb explosion” model.  
        关键词：Slow highly-charged ions(SHCI);Gallium nitride(GaN);Irradiation damage   
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        发布时间：2021-03-12
      • JIN Yunfan YAO Cunfeng SONG Yin LIU Jie WANG Zhiguang SUN Youmei ZHANG Chonghong DUAN Jinglai
        Issue 4, (2007)
        摘要：The irradiation experiments of thin C60 film stacks were performed by S,Fe,Xe,and U ions with energy of GeV delivered by HIRFL at Lanzhou in China,and Unilac in Germany respectively,and 120keV H ions delivered by ion Implantor at Institute of Modern Physics,Chinese Academy of Sciences. The structural stability of C60 films under the irradiation by swift heavy ions or high density electronic excitation effects were analyzed by means of FTIR,XRD,XPS and Raman scattering spectroscopies. The analysis results indicated that the irradiations induced the polymerization and destruction of C60 molecules,some components of high-temperature-high-pressure phase of the polymerized C60 appeared in the irradiated C60 films and finally amorphous transformation of C60 films took place. The electronic energy transfer dominates the damage process of C60 films. The partial recovery of the damage in irradiated C60 films at certain electronic energy loss is attributed to an annealing effect of high density electronic excitation.  
        关键词：Structural stability;C60 films;Swift heavy ions;High density electronic excitation effect   
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        发布时间：2021-03-12
      • LIU Chunbao1,2 ZHAO Zhiming1 WANG Zhiguang1 SONG Yin1 JIN Yunfan1 SUN Youmei1 LIU Jie1 YAO Cunfeng1 ZANG Hang1,2 1
        Issue 4, (2007)
        摘要：Thermally grown amorphous SiO2 films on single crystalline silicon were implanted at room temperature(RT) with 120keV C ions to 2.0 × 1017～8.6 × 1017 cm-2,then irradiated at RT by high energy Xe,U and Pb ions to 1.0 × 1010 ～ 3.8 × 1012 cm-2. The variation of chemical bonding configuration in these samples induced by high energy ion bombardments was investigated using Fourier Transformation Infrared(FTIR) spectroscopy. The obtained results showed that a large amount of Si-O-C and Si-C bonds was formed in the heavy ion irradiated C-doped amorphous SiO2 films. The SiOC bonds are of cage-,ring-or open-linked structures,and the cage-linked structure tends to ring-/open-linked structure with the increase of heavy ion irradiation fluence,electronic energy loss,or deposited energy density in the samples. The mechanism of SiOC formation induced by high energy heavy ion irradiations was briefly discussed.  
        关键词：Heavy ion irradiation;Implantation;SiOC   
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        发布时间：2021-03-12
      • Ma Yizhun1,2 Wang Zhiguang1 Song Yin1 Zhang Liqing1 Sun Youmei1 Yao Cunfeng1,2 1
        Issue 4, (2007)
        摘要：PVA/CMC hydrogels were irradiated using MeV electron beams. By analyzing structures,transparence,gel fraction and swelling ratio of the samples varying with the electron irradiation dose,we studied the gel properties of PVA/CMC hydrogels induced by electron beam irradiation. It was found that hydrogels with different quantities of PVA and the same quantity of CMC behave differently under MeV electron beam irradiation. The irradiated PVA/CMC hydrogels are of strong water absorbability after extraction,which implied that net-structures were formed in the hydrogels after irradiation. Several competing-reactions resulted in a complex relation between the gel fraction and the quantity of PVA. FTIR results showed that electron beam irradiation made secondary alcohol turn to tertiary alcohol by the hydrogen replacement,which led to crosslinking of samples.  
        关键词：Hydrogel;PVA/CMC;Electron beam irradiation   
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        发布时间：2021-03-12
      • WANG Zhiguang1 SONG Yin1 JIN Yunfan1 SUN Youmei1 ZHAO Zhiming1 LIU Jie1 ZHANG Chonghong 1 YAO Cunfeng 1,2 1
        Issue 4, (2007)
        摘要：Diamond-like-carbon films and graphite samples were implanted at room temperature(RT) using 100—120 keV N-ions to 5 × 1017 - 5 × 1018 cm-2,and then irradiated at RT using 345 MeV Xe,2.64 GeV U or 30 MeV C60 ions,respectively. The irradiated samples were characterized by FTIR,Raman,and XRD or XPS spectroscopes,and the formation of new chemical bonds and phases in the N-doped samples induced by heavy ion irradiations were studied. It was found that high-energy heavy ion irradiations could significantly induce the formation of CN bonds in all samples,high N-concentration and intense energy deposition result in the increment of sp3/sp2 bonding ratio and the enhancement of the formation of N-sp3C bonds that are needed for α-and β-C3N4 phase production. Furthermore,C60 ion irradiation could result in the formation of CNx and tetrahedral amorphous carbon in the C-doped graphite samples,whereas high-energy Xe and U ions could produce α-and β-C3N4 crystalline inclusions in the C-doped diamond-like-carbon samples.  
        关键词：N-ion implantation;High-energy heavy ion irradiation;DLC films;Graphite;Carbon-nitrides   
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        发布时间：2021-03-12
      • SUN Youmei LIU Jie WANG Zhiguang ZHANG Chonghong HOU Mingdong JIN Yunfan DUAN Jinglai SONG Yin XUE Zhihao
        Issue 4, (2007)
        摘要：Under the vacuum and room temperature environment,polyethyleneterephthalate(PET),polycarbonate(PC,Makrofol KG) and polyimide(PI) foil stacks were irradiated with various swift heavy ions(1.158GeV Fe56,1.755GeV Xe136 and 2.636GeV U238) . The damage processes in the irradiated polymer latent tracks were studied by X-ray diffraction(XRD),Fourier Transform Infrared(FTIR) spectroscopy and ultraviolet/visible(UV/Vis) spectroscopy in a very wide electronic stopping power range(from 1.9 to 17.1 keV·nm-1) and fluence range from 1×1010 to 3×1012 ions·cm-2. The degradation of main functional group,alkyne formation,amorphization and red shift of the absorption edge were observed. By quantitatively analyzing the main damages and applying the saturated track model,the mean damage radii of tracks of amorphization and alkyne formation process were obtained for Fe,Xe and U ion irradiation,respectively. The results were explained by the theoretical model.  
        关键词：Swift heavy ion;Polymer;Latent tracks;Damage effects   
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        发布时间：2021-03-12
      • HE Chaohui1,2 LI Yonghong1,2 YANG Hailiang2 1
        Issue 4, (2007)
        摘要：The Single Event Effect(SEE) simulation experiment was carried out on proton accelerators for Static Random Access Memories(SRAMs). A gold foil was used to scatter the proton beam so that it was suitable for proton SEE experiment. A system was designed for measuring the very low proton beam on devices. The Single Event Upest(SEU) cross section is of the order of 10-14 cm2/bit for SRAMs under proton irradiation. The SEU effect experiments were performed by using heavy ion accelerator and 252Cf source,too. The relation between SEU cross section and heavy ion Linear Energy Transfer(LET) was studied. The SEU heavy ion LET thresholds and the saturation SEU cross sections were obtained. Result on the saturation SEU cross sections were the same for using heavy ion accelerator or using 252Cf source. Therefore it is suitable to measure the saturation SEU cross section for SRAMs using 252Cf source instead of heavy ion accelerator. Heavy ion micro-beam SEE experiment was firstly performed and the SEU sensitive regions were found for SRAM produced in China. The SEE experiments were performed on neutron 14MeV generator and the SEU cross sections were obtained for SRAMs,too. To compare the ability of three different memories against soft errors,alpha particles’ irradiation experiments were done to simulate the alpha particles emitted from 232Th and 238U in encapsulation material. Soft errors are measured and the cross sections of SEU and Failures in Time(FIT) are calculated. Alpha particles’ irradiation experiments for routers were also done and the errors in natural environment were duplicated.  
        关键词：Single event effects;SRAM;Accelerator;Radiation source   
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        发布时间：2021-03-12
      • ZHANG Hong1 LUO Jialing1 CHAI Zhifang1,2 SUN Huibin1 1
        Issue 4, (2007)
        摘要：The distribution characteristics of organo-halogens in apple and their sources were studied by neutron activation analysis combined with statistical analysis. The results indicated that concentrations of organo-halogens in apple were in the order of organo-chlorine >> organo-bromine > organo-iodine,and concentrations of the organo-chlorine in four parts of apple were in the order of seed >> peel >> endocarp ≥ pulp. Also,the organo-chlorine,-bromine and -iodine in apple were found to have different sources. The latter two were mainly from naturally synthetic products by plant itself,while the former was mainly from anthropogenic pollutants.  
        关键词：Neutron activation analysis;Organo-halogen pollutants;Apple   
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        发布时间：2021-03-12
      • YANG Xiaomin LIU Qi FU Haiying YAO Side ZHU Zhiyong
        Issue 4, (2007)
        摘要：Hydrogels containing poly(vinyl alcohol)(PVA),poly(N-vinyl pyrrolidone)(PVP) and water soluble chitosan(ws-chitosan) have been prepared by gamma ray irradiation. The hydrogel properties were investigated in relation to the irradiation dose,the ws-chitosan content and the addition of plasticizers(poly(ethylene glycol)(PEG) or glycerol). It is found that the gel fraction increases with increasing of the irradiation dose up to 27 kGy and then levels off with further irradiation. Increasing ws-chitosan content and the addition of plasticizers(PEG or glycerol) will reduce the gel fraction and strength of the hydrogels,while the swelling capacity is improved significantly. The storage modulus obtained from rheological measurements reveals that the strength of the hydrogels increases with increasing of the irradiation dose and saturates at doses above 27 kGy.  
        关键词：Hydrogel;Plasticizer;Rheological property;Radiation synthesis   
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        发布时间：2021-03-12
      • CHEN Xiliang ZHANG Cong FU Haiying SONG Yufeng LIU Qi YANG Xiaomin ZHU Zhiyong
        Issue 4, (2007)
        摘要：The rheological property of HDPE/EVA system filled with carbon black(CB) is studied with Advanced Rheology Expand System(ARES). It is found that the appearance of the solid-like “second plateau” and the peak of loss factor in the low frequency region as well as the strong shear thinning effect are all related to the network formed by the interactions between particles and particles/polymer chains. The accelerated increase of complex viscosity with increasing of filler loading above 20 phr indicates that a rheological percolation structure of the filler has formed. Irradiation with gamma-ray affects the rheological behavior of the system greatly,i.e.,the peak of loss factor disappears and the dependence of the G′ on frequency becomes smaller,indicating cross-linking of the polymer molecules. At dose of 100 kGy an abnormal behavior is observed which can be partly attributed to the degradation of polymers.  
        关键词：HDPE/EVA/CB composite;Rheology;γ-irradiation   
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        发布时间：2021-03-12
      • ZHANG Yuanxun WANG Yinsong YANG Chuanjun LU Wenzhong ZHANG Guilin LI Yan
        Issue 4, (2007)
        摘要：Many kinds of advanced nuclear analytical methods and related techniques,i.e. particle induced X-ray emission(PIXE),laser particle spectroscopy(LPS),synchrotron radiation X-ray absorption fine structure(XAFS) and extended X-ray absorption fine structure(EXAFS),have been used to study the pollution states of atmospheric aerosol particulate matter in Shanghai urban districts and suburbs in recent years. The superiorities of nuclear analysis technology such as high sensitivity,time-saving,nondestructive,multi-elements analysis at the same time and so on are fully displayed. The synthetic researches of the particulate matter including morphology,particle size distribution,mass concentration,elemental concentration,chemical valence state and source identification are performed.  
        关键词：Nuclear analysis techniques;Air particulate matter;Particle size distribution;Elemental concentration;Chemical valence state;Pollution character   
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        发布时间：2021-03-12
      • LI Xiaolin1 MAO Xueying2 1
        Issue 4, (2007)
        摘要：The interferences in determination of trace element Pt in aerosol particles by instrumental neutron activation analysis were preliminary studied. The mathematical correction method was used to correct the interference contribution of Ca in Pt determination. The results of this study show that the mathematical correction method is reliable.  
        关键词：Neutron activation analysis;Aerosol;Platinum   
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        发布时间：2021-03-12
      • RAN Tiecheng1,2 LIU Ruili1,2 ZHU Ying1,2 LI Qingnuan1 ZHU Jianhua3 LI Wenxin1 1
        Issue 4, (2007)
        摘要：The synthesized C60NM,after connecting with the stable iodine,was radiolabeled with iodine-125 through isotope exchanging. The bio-distribution of the radioiodinated compound in rats was studied. The results indicated that 125I-C60NM can target in lymphatic node and it has a good lympha targeting effect.  
        关键词：125I-fullerene pyrrolidine benzoyl nitrogen mustard;Bio-distribution   
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        发布时间：2021-03-12
      • WEI Yingguang1 LIU Senlin2 SUN Lifeng3 WANG Yanfeng1 1
        Issue 4, (2007)
        摘要：The energy response of a high sensitivity environmental neutron dose equivalent meter is calculated by MCNP4c code. The calculated response curve agrees with H *(10) curve in ICRP 74 report in interesting neutron energy regions. By comparison between the experimental results and the calculated values,the relative deviation is -21.6%. Experiments show that MCNP4C code can be applied to calculate neutron response for the high sensitivity environmental neutron dose equivalent meter,and it can also raise the work efficiency and help to analyze the experimental results.  
        关键词：Environmental neutron;High sensitivity;Dose equivalent meter;Response curve;Experimental validation CLC TL816   
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        发布时间：2021-03-12
      • LEI Jiarong WEI Xiye YUAN Yonggang ZHAO Lin ZHAO Minzhi CUI Gaoxian
        Issue 4, (2007)
        摘要：The photon energy spectrum is an important parameter for pulsed photon field,and a cascading detector can be used to measure the photon flux spectrum. The response function for photons with different energy for the detector is the basis of unfolding photon spectrum. In this paper,the response function was simulated using MCNP/4C,and the calculated response function for gamma rays with representative energies was verified through thermoluminescence detection technology. It shows that the simulated results agree well with the measured results for the response function of the cascading detector.  
        关键词：Cascading detector;Photon spectrum;Response function;MCNP/4C   
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        <引用本文> <批量引用> 7219212 false
        发布时间：2021-03-12
      • YUAN Yonggang LEI Jiarong ZHAO Minzhi
        Issue 4, (2007)
        摘要：The irradiation cases with lead shield were designed to successfully measure photon fluence at every designated point in the radiation flied. The main shortcoming of previous,i.e. larger dispersion of the measurement data at the same point,was overcome due to the use of lead shield to weaken effect of low-energy scattered γ-ray on the detector. Effectiveness of using these irradiation cases was experimentally verified,and the data on absorbed dose photon fluence rate at several points were obtained with a total uncertainty of less than 7%.  
        关键词：Photon fluence;Thermoluminescence detector;Mass and energy absorption coefficient   
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        发布时间：2021-03-12
      • TUO Xianguo1 MU Keliang1 LEI Jiarong2 LI Xiangyang1 YANG Xuemei1 1
        Issue 4, (2007)
        摘要：The paper introduces a tritium measuring instrument,in which technologies such as nuclear radiation detection,electronics,information processing,etc. have been incorporated. By using the gas-flow proportional counter,advanced microprocessor,as well as data and information processing technique,the instrument has a low power consumption and high detect efficiency. The experimental results show that the plateau length is 300 V;the plateau slope 0.608%/100V,the lower detection limit 0.221 Bq·cm-2(for 600 s),the stability of the instrument 0.56%/h,the variance coefficient 2.88%,and the detection efficiency 84%(for the 2π surface emissivity of 3H source 1307/min-1).  
        关键词：Tritium measure;High detect efficiency;Capability   
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        发布时间：2021-03-12
      • MU Keliang TUO Xianguo LI Xiangyang XI Dashun
        Issue 4, (2007)
        摘要：A multichannel dosimeter with high precision P-Si semiconductor detectors is introduced. The meter has been applied in the field of radiation for on-line or real-time examination. Besides,in nuclear medicine it can be also used to monitor and measure the dose when patients are under the radiation therapy. The instrument is primarily operated,and some of its characteristic are as follows:the sensitive energy range for X-ray is between 0.1 and 15 MeV,the detection sensitivity is 0.05 Gy/min,the input bias current is about 50×10-15 A,and its linearity is ideal. Moreover,the printer and LCD are attached to the meter to increase its intelligence.  
        关键词：P-Si semiconductor detector;Multichannel;Ideal linearity   
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        发布时间：2021-03-12
      • XIE Liping1 KANG Mingjie1 DU Minxuan1 DU Yi2 1
        Issue 4, (2007)
        摘要：Adopting the ion implantation technology in the fabrication of new type of semiconductor,a portable semiconductor nuclear radiation meter has been developed. The technical parameters of the new meter are improved clearly as compared with the conventional detectors. So it can be widely used for detecting the X-rays and γ-rays in the space and the environment.  
        关键词：Ion implantation;Semiconductor detector;Nuclear radiation meter   
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        发布时间：2021-03-12
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