最新刊期
卷 0 ， 期 0 ， 2020
- 关键词：Energy resolution;passivated;Ion implantation;semiconductor
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发布时间：2022-09-13 - 摘要：A two-dimensional multiwire proportional chamber (MWPC) imaging device with delay line readout is described. It consists of a multiwire proportional chamber, a delay line, a main amplifier, a timing single channel amplitude analyser and a time to amplitude converter. The MWPC is based on the gas flow of Ar-CO2. Its sensitive area is 20×20cm2. Spatial resolution is 2.06mm. A phase-compensated distributive parameter electromagnetic delay line is used. Its delay rate is 6.3ns/mm, the rise-time is 100 ns The time shift of the timer is 1 ns (for dynamic range 13:1) . The radioactive distribution of the 14C labelled compounds on the paper chromatogram and photograph of the special ring model imaging are given.关键词：two dimesional;multiwire proportional chamber;image;delay line;readout;timing single channel;amplitude analyser;time-amplitude converter;Spatial resolution;time shift
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发布时间：2022-09-13 - 摘要：This paper summarizes the investigation and construction of a vacuum fission chamber and gives the measurement results of primary characteristics of the detector. The experimental data are analysed and discussed. It is shown from the experimental results that vacnnm fission chamber is another type of applicable reactor detectors and is much better than usual boron ion chamber or self-power detector on some characteristics and should be paid great attention to.关键词：vacuum fission chamber;Reactor
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发布时间：2022-09-13 - 摘要：The parameters including knot numbers, knot positions and the weights associated with the systematic errors in the cubic spline curve fitting method were discussed. The conditions of using fitting criterion were given as well.关键词：spline function;Curve fitting
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发布时间：2022-09-13 - 摘要：The γ spectra from 27A1 (p,γ) 28Si reaction were fitted by using Lorentzian and Gaussian convolutions. The widths of 28Si levels produced by resonance reactions have been analyzed for the proton bombarding energy of 992 keV, 885keV, 774 keV and so on. The results of 「992=105±4 eV, 「885=10.8±3.0 еV, 「774=14.0±0.5 eV, 「767 =45±6 eV, 「937=137±14 еV and 「1800=470±30 eV were also compared with other published results.关键词：Lorentzian signal;convolution of Lorentzian and Gaussian;energy level width;(ρ, γ) reaction
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发布时间：2022-09-13 - 摘要：The fringing field of a dipole magnet with a c-type circuit and homogeneous field in the gap has been measured including the distributions of fringing fields with and without magnetic shield. The measured data was analyzed by using the concept of virtual field boundary.关键词：Magnet;measurement of fringing field;virtual field boundary;magnetic shield
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发布时间：2022-09-13 - 摘要：DL- (4,5-2H) -leucine was prepared by catalytic deuteration of its double-bond precursor. Its trifluoroacetyl butanolic ester derivative was prepared and the deuterium content was estimated by GC-MS. Analysis of the m/e=182 fragment by Biemann's method revealed that the 2H content varied from 0 to 6. The percentage of molecules containing no deuterium atom was 16.4, indicating that the abundance of labelled molecules (regardless of the number of deuterium atoms in each molecule) was 83.6%. Calculated from the intensity of the fragments m/e=182, 153, 140 by Biemann's method the abundances of labelled atoms at different C positions of the leucine molecule was: C1—0%; C2—2.9%; C3—22.5%; C4, C5, C6—54.2% (average) .关键词：2Н-leucine;gas-chromatography mass-spectrometry;abundance analysis
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发布时间：2022-09-13 - 摘要：DL-[4-3H]-phenylalanine was prepared by catalytic halogen-tritium exchange method The labelled T was removed by repeated equilibration with methanol and water. Finally the product was purified by paper chromatograph. The specific radioactivity of DL-[4-3H]-phenylalanine is 16.6 Ci/mmol. The radiochemical purity is more than 95%.关键词：Tritium labelled;halogen-tritium exchange;radiochromatographic scan;Phenylalanine
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发布时间：2022-09-13 - 关键词：238Pu source;coating layer on tape;thickness measurement with X-ray fluorescence instrument
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发布时间：2022-09-13 - 摘要：Simultaneous determination of microamounts of antimony and copper has been investigated by self-made teflon hanging mercury drop electrode and F-78 pulse polarograph. This method was applied to Na123I injection with satisfactory results.关键词：Na123I solution;microamount of antimony aud copper;differential pulse anodic stripping voltammery
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发布时间：2022-09-13 - 摘要：Classical activation method is often used in the reactor physical experiment forrelative measurements of neutron flux distribution in a reactor, this method takes much time and can not get the results quickly. By using a kind of micro-neutron detector with conventional electronic equipment and mechanical device, we measured the axis relative distribution of neutron flux on-line in the light water zero-power reactor. The deviation of the results obtained by using microdetector on-line from off-line is less than 3%.关键词：zero-power reactor;relative distribution of neutron flux
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发布时间：2022-09-13 - 摘要：14 MeV neutron beam was used to irradiate gentamycin, medemycin and orange. The yield antibiotics were raised of 3% to 20% after irradiation; By irradiation of orange seed, pollen and branch improvement of rate of germination, fruit seed number and scion survival rate were observed and a number of new variety were developed by mutation.关键词：Fast neutron;irradiation breeding;gentamycin;medemycin;orange;scion
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发布时间：2022-09-13 - 摘要：This paper describes a method, by which the TLD (thermoluminescent detector) wrapped in a cadmium enclosure can be used to measure thermal neutron dose equivalent in environmental monitoring. To calibrate the TLD wrapped in a cadium enclosure it is not necessary to use the reactor thermal neutron source, it can be simply accomplished with a 60Co-γ source.The formula used to calculate the equivalent thermal neutron dose is given.关键词：Thermal neutron;Dose;Dose equivalent;Dosimeter;cadmium;thermoluminescent
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发布时间：2022-09-13 - 摘要：The advantages of the device are simple in structure, easy for operation and stablein performance. It provides multifunction such as generating both the small size aerosol and large size dust, conducting the filtration efficiency and performance tests for dusts for protection equipment or filter media.Some new techniques have been employed to produce test dust: Ultrasonic fog generator for producing aerosol and silicon controlled electromagnetic oscillation methods for generating dust. Therefore the concentration and quantity of the test dust are stable and controllable.The device has the maximum detectable efficiency of 99.99% for aerosol and 99.5%for dust.The tests on various dust protection equipment and filter midia showed the good stability and reproducibility of the device.关键词：Aerosol;dust;test dust;weighing method;counting method;Filtration efficiency;Particle size;monodisperse aerosol
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发布时间：2022-09-13 - 摘要：The preliminary experience of SPECT technique in liver disease diagnosis is described.SPECT is superior to CLS in the detection and localization of lesion less than 3.5 cm in diameter.关键词：Single photon emission computed tomography;three-dimensional matrix image;liver scintigraphy;technetium-99m-phytate
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发布时间：2022-09-13 - 摘要：Seven human peripheral blood samples under the thermo-regulation were exposed at the dose of 5,25,50,100 and 200 rads respectively by 60Co γ-rays. The chromosome aberration frequencies at different dose were observed with 7723 metaphase cells and analyzed by employing spontaneous human chromosome aberration frequency as control group according to the principle of least square method. A dose-effect curve from 0—200 rad was plotted. The results show that through 0—200 rad low dose irradiation the relationship between dose and chromosome aberration frequencious is linear thus it canbe also served as a "biological dosimeter".关键词：60Co-gamma ray;human lymphocytes;Chromosome aberration;biological dosimeter
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发布时间：2022-09-13 - 关键词：archaeology;14C-dating;ion beam analysis;activation;analysis
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发布时间：2022-09-13 - 关键词：radioisotope relay;design philosophy
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发布时间：2022-09-13 - 关键词：distribution and whole-body autoradiography;3H-dimethy-(-)-curine dimethochloride
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发布时间：2022-09-13 - 关键词：selective absorption for X-rays;art paper;thickness of coating layer
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发布时间：2022-09-13
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