最新刊期
      卷 0 ， 期 0 ， 2020
      • Issue 4, (1999)
        摘要：Differential elastic 160° backscattering cross sections of 0.15-2.00MeV protons for natural boron have been measured. The lowest proton energy used in the experiment is in the Rutherford backscattering energy region. The measured cross sections are presented in tabular and graphical forms and compared with previous data.  
        关键词：Proton;Backscattering;Cross sections   
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        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：The coal mining and the related surface projects are extremely harassed by the underground karst depressed columns. This paper discussed the surface Rn concentration’s abnormality caused by the karst depressed columns. It is concluded that different kinds of karst depressed column can cause different Rn concentration’s abnormality. The α-cup Rn measuring instrument was used for detecting Rn abnormality on the surface in order to locate the underground karst depressed columns.  
        关键词：Rn measurement;Karst depressed column;α cup   
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        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：By using a method for calculating the roof thickness for shielding a radiation source with angular distribution, the required optimized concrete roof thickness for shielding high-energy X-rays produced by L3000 9MeV electron linear accelerator was found to be 30cm. The dosimetric measurements made after the accelerater building was completed showed that the shielding design was safe and economic, and the dose equivalent rate of the skyshine radiation was close to the background value, reaching to a level as low as reasonably achievable.  
        关键词：Electron linear accelerator;Shielding calculation;Roof thickness;Skyshine radiation   
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        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：The inorganic phosphate release in CMP nucleotide implanted by N+ ions includes fast reaction and slow one, and the latter is influenced by heat-treatment. With heat-treatments of lower than 353 K and of 368K, it was found that the kinetic process of phosphate release followed the first and second order reaction mode respectively. Moreover, the kinetic equations and the rate constants were deduced.  
        关键词：Ion implantation;CMP;Phosphate release;Kinetics   
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        <引用本文> <批量引用> 7393362 false
        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：The principle of the self-adaptive feed-forward (SAFF) control to improve the beam quality of linac is introduced. The analytical procedure for calculating the control signals, the structure of a practical control system, and applications of SAFF in klystron, RF gun, and linac are presented, especially the application in the thermionic gun whose response is non-linear, time-variant and of large time-delay. The described control system is operational and some primary experimental results have been obtained, including the control of amplitude and phase fluctuations of the klystron output, the microwave field in the gun cavity and linac.  
        关键词：Control;RF thermionic gun;Linac;Klystron;Amplitude;Phase   
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        <引用本文> <批量引用> 7393374 false
        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：A method for measuring trace elements in food by PIXE technique is presented. Concentrations of trace elements in food from high incidence district of gastric carcinoma, Qixia county, and from low incidence district, Cangshan county, both in Shandong province, are determined. The t-test indicates that the concentrations of Sr, Ni, Cu, Mn and Fe in food from Qixia county are significantly higher than those from Cangshan county, but a converse result is obtained for Se.  
        关键词：PIXE;Gastric carcinoma;Food;Trace elements   
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        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：This paper reports the experimental results of identifying jade by the proton induced X-ray emission (PIXE) technique. The major, minor and trace elements for various kinds of jade were measured non-destructively. It is found that the jade can be classified, according to the chemical compositions determined by PIXE, and the concentration of some trace elements may be useful in finding sources of the jade.  
        关键词：Jade;Identification;X-ray fluorescence analysis   
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        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：The c-axis and a-axis single crystals of a -Al2O3 implanted with 1 ×1017/cm2 of 171keV Y ions, and 9×1017/cm2 of 158keV Pt ions, respectively, have been investigated. The implantation was carried out at room temperature by using a MEVVA machine. Annealing was performed isothermally in air ambient at temperature in the range from 500℃ to 1050℃. The rutherford backscattering spectrometry and channeling of 2.4MeV He+ was used to study the depth distribution of lattice damage and implants. The microhardness and resistivity of the implanted layer were also measured. Results on structural changes were interpreted on the basis of the physical property measurements. The precipitates of implanted Pt were examined by XRD.  
        关键词：Ion implantation;Sapphire;Lattice damage;Surface modification   
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        <引用本文> <批量引用> 7393420 false
        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：The radon self-migration law is discussed. It is shown that, in the air under an idealized condition (no convection, no pressure, temperature and potential differences, and sealed), the contribution of diffusing of radon and its daughters to their migration is less than 10%, the descending purely caused by gravity is less than 45%; and the contribution purely given by buoyancy is more than 45%. The radon measuring method and application in geology is also introduced in the paper.  
        关键词：Radon migration;Radon measurement;Geologic application   
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        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：With SnCl2 as reductant, tartrate as intermediate ligand, and with the aid of paper chromatography on three kinds of developing agents, the 99mTo, 188Re and stable rhenium labelling chemistry with regard to o-phenanthroline (Phen) have been studied. The labelling ratio of 99mTc-Phen can reach to 95%. For different pH values of media and at different labelling temperatures, the 99mTo-Phen products can be different, and they can have different paper chromatographic behavior in some developing agents. The labelling of 188Re and stable rhenium is more difficult than that of 99mTc. Even if large quantity of SnCl2 is used, the labelling ratio of 188Re-phen is singnificantly lower than 99mTo-Phen: the highest labelling ratio is only 50%.  
        关键词：o-Phenanthroline;99mTo labelling;188Re labelling;Stable Re labelling;Paper chromatography;Apparent charge number   
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        <引用本文> <批量引用> 7393481 false
        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：An optical control system used for adjusting the source’s parameters of an ion separator is described. There are two slice microcomputers at HV terminal and the ground respectively. These microcomputers communicate each other with the full-duplex mode through two pieces of optical fiber, in which many parameters are time-share transmitted in the form of optical pulse. This system can stabilize the arc current and temperature, adjust and display all parameters and has safe-guard ability. At HV terminal, the optical coupling technique is used for connecting the CPU and the ion source, and at the ground the CPU can communicate with a control microcomputer.  
        关键词：Optical fiber;Optical coupling;Full-duplex;Serial communication;Time-share transmission;Accelerator   
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        <引用本文> <批量引用> 7393508 false
        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：The keV N+ ions were implanted into several kinds of amino acids in solid state. The EPR and infrared (IR) spectroscopy were applied to study the induced damage. It was shown that severe implantation damages arose, the molecule decomposed, the IR absorption became weak and a great number of fragments were formed. And the radical fragments’ type and quantity sensitively varied with fluence of the implanted ions. Some of the fragments were even recomposed to form new chemical compounds, among which amides and new amino acids were the most probable forms.  
        关键词：Ion implantation;Implantation damage;Amino acids   
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        <引用本文> <批量引用> 7393522 false
        发布时间：2021-03-12
      • Issue 4, (1999)
        摘要：In this paper described is a computer-controlled wavelength scanning system, which serves as an important accessory of Seya-Namioka monochromator installed on U10A beamime at NSRL.  
        关键词：Monochromator;Grating;Wavelength scanning   
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        发布时间：2021-03-12
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