最新刊期
      卷 0 ， 期 0 ， 2020
      • ZHANG Yaofeng WANG Yong WEI Wei WANG Jianping FAN Le JIANG Daoman
        Issue 3, (2006)
        摘要：The coating technology of inner wall of stainless steel pipe with TiN film by DC sputtering is presented in detail in this paper. The corresponding parameters of the coating process are described and the vacuum characteristics of the coated pipe are determined. Very low outgassing rate shows that DC sputtering can be used to coat stainless steel pipe with TiN film rapidly and effectively, and that the coating technique is a new and effective way for surface treatments of vacuum chambers of some accelerators.  
        关键词：TiN material;DC sputtering;Outgassing rate   
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        发布时间：2021-03-12
      • XIA Chenfang GU Ming ZHANG Jianbing ZHONG Shaopeng
        Issue 3, (2006)
        摘要：The mechanism of microwave switches is analyzed and the experiment results are presented. It is proved by experiments that the spontaneous breakdown can be used as a high power microwave switch in a high vacuum double T resonant cavity with the output pulse power of more than 100 MW. Meanwhile, the experiment indicates that the output pulse power is changing with different breakdown moment. A design of the provocative gas discharge switch is also presented in this paper with some primary experiments results.  
        关键词：Microwave switch;Double T cavity;Pulse compression;SES   
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        发布时间：2021-03-12
      • WANG Naxiu1 CHEN Yonglin1 YAN Heping1 JIANG Dikui1 ZHU Xikai1 Guo Panlin1 WANG Futang2 DING Liren2 SHI Jin3 LI Wei3 LU Di4 ZOU Yaming4 1
        Issue 3, (2006)
        摘要：Design and manufacture of the cryogenic and superconductor system for Shanghai Electron Beam Ion Trap (EBIT) have been reported in this paper. The adopted measures to improve the system’s performance and experiment results are also described. In order to reduce the consumption of liquid helium, the cryogenic system includes two cooling-shields cooled by two stage G-M refrigerator. The consumption of liquid helium is 1.1 L/h on average in 16 h, the peak of magnetic field strength of superconducting magnet is up to 5.3 T, uniformity is better than 2×10-4 in the range of ±10 mm on the central axis of magnet, and the time decaying ratio of magnet is better than 1×10-4 in 8 h with closed-loop current. All these show that user’s basic demands can be met.  
        关键词：Electron beam ion trap (EBIT);Superconductor;Cooling-shield;G-M refrigerator   
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        发布时间：2021-03-12
      • WANG Pingsheng HUANG Donghui CHEN Xilin TIAN Weizhi NI Bangfa ZHANG Lanzhi LIU Cunxiong ZHANG Guiying LIU Likun
        Issue 3, (2006)
        摘要：The half-life of 97Zr, used for the calculation of thermal/epithermal neutron flux ratio in k0-NAA, is re-determined using three measurement systems with different pulse processing principles. The result of (16.755±0.013) h clarifies the discrepancy between two widely used literature values, (16.744±0.011) h and (16.90±0.05) h. Different dead-time correction methods used on various measurement systems are evaluated. Factors influencing precise measurement of relative peak counting rates are discussed in time-series measurements over a dynamic range of 1000-fold radioactive intensities (10 half-lives).  
        关键词：Half-life;External source monitor;Internal source monitor;Life time extension   
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        发布时间：2021-03-12
      • LI Zhengping1 XU Chao1 WU Ruisheng2 TAN Shoubiao1 1
        Issue 3, (2006)
        摘要：As an example, we have calculated the radiation dose distribution near by a γ-ray density meter equipped in a 1600 type dredge ship, using Geant 4 (Monte Carlo simulation software). The most serious radiation leakage is found in the region close to the detector and it’s safe for using the γ-ray density meter under normal working condition. But under some abnormal condition such as the empty pipe, the density meter will detect a huge amount of radiation. For providing a safe circumstance, additional shield should be adopted. In fact a piece of steel plate of φ 50 cm ×7 cm in thickness could prevent most of escaping radiation and ensure the safety.  
        关键词：Radiation dose distribution;Monte Carlo method;Geant 4   
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        发布时间：2021-03-12
      • CHENG Shuo WANG Wei TAN Mingguang CHEN Jianmin ZHANG Guilin LI Yan
        Issue 3, (2006)
        摘要：The elemental concentration of water-soluble component of PM2.5 collected in Wusong Industrial Area, Shanghai was measured by ICP-MS. Studies on the cytotoxicities of such component were carried out. The rate of cell proliferation was detected by MTT assay. Both SOD and MDA assays were adopted for assessing the ability to cause cell oxidative damage. Agar gel electrophoresis and FCM were used to examine the cellular DNA damage. The results show that the water-soluble metal with the highest concentration in PM2.5 is zinc. Our data demonstrate that the water-soluble component of PM2.5 can mediate cell proliferation, cause cell oxidative damage and attenuate the cell DNA synthesis, but can not cause cell apoptosis action. In conclusion, these water soluble metal ions in PM2.5 displayed the synergic effects.  
        关键词：Airborne particulate matter;PM2.5;Oxidative damage;Cell apoptosis;Zinc ion   
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        发布时间：2021-03-12
      • FU Jiexiong1,2 ZHANG Xinbao1 QI Yongqing1,2 HE Xiubin1 WEN Anbang1 1
        Issue 3, (2006)
        摘要：Based on 137Cs diffusion and migration processes in soil, a penetration process model is developed for 137Cs depth distribution in uncultivated soil without erosion. By using the model, the changes of the 137Cs depth distribution with time for the 137Cs reference inventory profiles at Kaixian, Chongqing and Zichang, Shaanxi, are tentatively reconstructed. The 137Cs depth distribution in the Kaixian profile (2004) has an exponential decrease shape with depth. The highest 137Cs concentration occurs in the surface horizon, and the coefficient for 137Cs depth distribution shape is h0=0.0997 cm-1, with the related depth moving coefficient D=0.8006 cm2·a-1. The 137Cs depth distribution in the Zichang profile (2001) has a non-exponential decrease shape with depth. The highest 137Cs concentration occurs in the sub-surface horizon, and the coefficient for 137Cs depth distribution shape of the whole profile is h0=0.0825 cm-1, with the related depth moving coefficient D=1.24 cm2·a-1. The higher 137Cs concentration in the subsurface horizon than in the surface horizon, which is represented by the non-exponential decrease shape of 137Cs depth distribution with a negative value of D, is probably attributed to the fact that either porosity or moisture penetration of soil decreases with the depth’s increase in the surface and sub-surface horizons, thus leading to a sudden decline of the 137Cs penetration rate.  
        关键词：Uncultivated soil;137Cs depth distribution;Penetration process model;Diffusion;Migration   
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        发布时间：2021-03-12
      • CHEN Panxun ZHOU Kaiming
        Issue 3, (2006)
        摘要：A new phenomenon of single- event upset is introduced. The transient signal is produced in the output of analog circuits after a heavy ion strikes. The transient upset can influence the circuit connected with the output of analog circuits. For example, the output of operational amplifier can be connected with the input of a digital counter, and the pulse of sufficiently high transient output induced by an ion can increase counts of the counter. On the other hand, the transient voltage signal at the output of analog circuits can change the state of other circuits.  
        关键词：Analog circuit;Single-event transient(SET);Pulse laser;Linear energy transfer(LET)   
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        发布时间：2021-03-12
      • YANG Huaimin XU Xi DENG Jianhong ZHAN Junling ZHAO Juchao WANG Xuli YUAN Guohuo
        Issue 3, (2006)
        摘要：The characteristics’ degradation and X-ray enhancement effects of N80C196KC20 chips were presented in this paper. The X-ray and 60Co irradiations of N80C196KC20 chips from Intel Company were performed to investigate the response of operating currents Icc. The operation failure symbolizes the total dose response of the chips. The total dose failure level of the chips is very low, and the γ total dose failure is about 165 Gy(Si). The operating current of the chip increases significantly when failure of the chip happens. The X-ray enhanced factor of N80C196KC20 chip is measured and the X-ray enhancement mechanism is studied.  
        关键词：Radiation effects;Total ionizing dose;Computer chip;X-ray dose enhancement   
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        发布时间：2021-03-12
      • ZHU Ying1,3 ZHAO Qunfen1,3 CAI Xiaoqing1,3 LI Yuguo1 LI Wenxin1 1
        Issue 3, (2006)
        摘要：The uptake of CNTs by Stylonychia mytilus and their distribution during the dividing process of the cells were observed with optical microscope for the first time. The dose-effect relationship between concentration of CNTs and surviving rate of Stylonychia mytilus was measured. The surviving rates were found to be about 111%, 107%, 75%, 70%, 53%, 43%, 38% on the fifth day after adding CNTs for the concentrations of 0.1, 0.5, 1, 5, 10, 50, 200 μg·mL?1, respectively. The result showed that high concentration of CNTs exhibited a dose-dependent inhibition to the cells, whereas very low concentration of CNTs was likely to stimulate the growth of the cells. To understand the inhibition from the CNTs, the propidium iodide was used to dye the macronucleus of Stylonychia mytilus. Images from fluorescent microscope showed that the damage occurred on the macronucleus and membrane of the cells.  
        关键词：Stylonychia mytilus;CNTs;Toxicity;Surviving rate;Macronucleus   
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        发布时间：2021-03-12
      • ZHOU Wei YIN Duanzhi WANG Yongxian
        Issue 3, (2006)
        摘要：Small animal PET appears to be developed as a powerful tool for the animal model research. This paper provides a review of the development of small animal PET and the applications in glucose metabolism study in brain and heart, neuroreceptor imaging, oncology, reporter gene expression imaging and antisense imaging. In addition the future of small animal PET is also discussed.  
        关键词：Small animal PET;Animal model;Animal imaging   
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        发布时间：2021-03-12
      • WU Jianfeng JIN Yuren ZHOU Guoqing ZHANG Lixing
        Issue 3, (2006)
        摘要：The high-purity nitric acid and hydrochloric acid were prepared by high-speed countercurrent chromatography(HSCCC), using the 0.25 mol/L tri-octyl-phosphorous oxide in heptane as the stationary phase, and the normal nitric acid and hydrochloric acid were used as mobile phase. The results show that the uranium contained in the acid purified is reduced to lower than 1 pg/mL, which is close to the content of uranium in the high-purity water and the high-purity acid prepared by isothermal evaporation and sub-boil distillation.  
        关键词：HSCCC;ICP-MS;Uranium;High-purity acid   
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        发布时间：2021-03-12
      • XIA Xiulong
        Issue 3, (2006)
        摘要：A comprehensive study was carried out to uncover the influence of process conditions, such as total stage number, feeding point, reflux ratio and distillation rate, on the separation capability. Both concentration and temperature distribution along the distillation column were obtained. As the reflux ratio increases and the feeding point moves towards the bottom, HD concentrations in condenser and reboiler are decreased. With the increase of distillation rate the HD concentration in reboiler increases as well, and there are remarkable differences in separation performance between H2/HD and D2/DT system.  
        关键词：Hydrogen isotopes;Cryogenic distillation;Tritium   
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        发布时间：2021-03-12
      • CHEN Guojie CAO Hui XIE Jianing
        Issue 3, (2006)
        摘要：A measurement method of liquid level of a coke-cracking tower based on dual-energy γ-ray transmission is presented, Both liquid level and height of foam in a coke-cracking tower have been determined by using the measured real-time curves. It was shown that the productive efficiency was raised, the productive cycle was shortened from 23 h to 16 h, and the defoamer was saved by 12%. Meanwhile, by using rod-like radioactive sources and high performance γ-ray spectrometer, both precision and stability of the measurement were improved, e.g. the measurement error of liquid level was less than 4.3%.  
        关键词：Dual-energy γ-ray;Liquid level gauge;Rod-like radioactive source;Coke-cracking tower   
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        发布时间：2021-03-12
      • LIU Suping GONG Jian HAO Fanhua WU Huailong HU Guangchun XIANG Yongchun ZHE Rende ZHANG Jianhua
        Issue 3, (2006)
        摘要：Based on the concept of relative detection efficiency, some experiments have been conducted to measure the isotopic abundance and the age of the plutonium material in a sealed container by a high-resolution γ-ray spectrometer. The PC/FRAM software analyzes the spectra. The study shows that the analysis precision of the isotopic abundance and the age will rise as the spectral measurement precision increases, and that if the spectral measurement precision is not high enough, the analyzed results by the PC/FRAM software might be unsatisfactory. Hence, the study suggests that a spectral peak should be monitored to shed light on the spectral measurement precision during the spectrum acquisition process.  
        关键词：Relative detection efficiency;PC/FRAM;Plutonium material;Isotopic abundance;Age   
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        发布时间：2021-03-12
      • HUO Xiukun CHENG Zhiyou
        Issue 3, (2006)
        摘要：Many changes have taken place in CT technology since it was invented. These changes not only appear in computer, detector and X ray technology but also in image reconstruction algorithm. A new kind of CT image reconstruction algorithm named Intermediate Function Algorithm is presented in this paper. This algorithm can be used both in fan-beam and cone-beam scan. The aim of the research is to find an effective reconstruction algorithm which can be used in cone-beam CT in the future.  
        关键词：Helical CT;Intermediate function;Cone-beam scan;Reconstruction algorithm   
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        发布时间：2021-03-12
      • ZHAO Jianxing TANG Kaiyong XIAO Wuyun ZHU Hongying LI Yuanfang
        Issue 3, (2006)
        摘要：The requirements of the temperature control in thermoluminescence(TL) dating were described briefly. The basic principles of heating control and application design to achieve high accuracy were introduced. Heating curves of RGD-3B TL reader are measured as an applied example, and the results show that high accuracy and good repeatability can be acquired.  
        关键词：Thermoluminescence;Dating;Temperature control   
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        发布时间：2021-03-12
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