最新刊期
卷 0 ， 期 0 ， 2020
- 摘要：A method and relevant apparatus for the production of high purity 15N2- enriched nitrogen gas, with （15NH4）2SO4 as starting material are reported. The overall yield of 15N is 96.9%- 98.4%, and the average contents of 15NH3, and 15NO are lower than 1 μg/L. By using this apparatus 0 .5 to 10L of 15Ns gas can be produced. The purity is high enough for the biological nitrogen- fixation studies .关键词：Isotope;15N2 gas;Biological nitrogen fixation
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发布时间：2021-04-09 - 摘要：According to the peculiarity in non-oil logging , such as small diameter （<60mm） and shallow depth （ < 1000m）, some technical questions for the design of gamma- ray borehole logging instruments have been discussed, which include portability of the instrument, measurement precision, signal transmission mode , apectrum stabilization and microcomputerization.关键词：Gamma- ray spectrometric logging instrument;Current pulse analogue transmission;Spectrum stabilization by computer software;Notebook computer system
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发布时间：2021-04-09 - 摘要：The magnetic properties and microstructure of the Nd3/8Fe 74/8B21/4 bonded magnethave been investigated in detail by X-ray diffraction and Mossbauer spectroscopyThe samples used for the study were taken from the melt-spun allpy ribbons at 650℃for 4 minhas good magnetic properties.The study on microstructure shows that it consists oftetragonal Fe3B as main phase（about 90% volume fraction）and Nd2Fe14B crystallitephase（less than 10%）.In addition, a small amount of Fe2B phase may be present.关键词：Melt-spun permanent magnet material;Magnetic properties;Mossbauereffect;Microstructure
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发布时间：2021-04-09 - 摘要：The methods for separation and analysis of trace rhenium from rock samples have been studied and two kinds of separation procedures for radiochemical neutron activation analysis（RNNA） compared. The results show that the crown ether extraction- neutron activation method can be satisfactorily applied to the separation and determination of trace rhenium in rock samples and complex systems. Rhenium content in rocks is determined to be about 1ng/g.关键词：Rock;Rhenium;Neutron activation analysis;Crown ether
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发布时间：2021-04-09 - 摘要：An electroplating method for the preparation of Pa sources is described, and themain factors （such as pH value of solution electroplating time and current density）influencing the electroplating of Pa are tested and discussed with 233Pa as a tracer. Athin and uniform electroplating Pa-Layer of 1mg/cm2 thick on thin stainless steeldisk was obtained. The Pa source was measured by HPGe detector to determine thechemical efficiency.
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发布时间：2021-04-09 - 摘要：The Al/Al2O3 bilayer coatings have been deposited on DK45 steel and ALTi alloyby using the ion beam assisted deposition （IBAD） method. Sample’s corrosionresistance was evaluated by electrochemical method, and their surface hardness andsample’s properties was studied. Tt was shown that the deposition of AL/Al2O3 bilayercan greatly improve sample’s corrosion resistance, surface gardness and tribologicalproperties.关键词：Ion beam assisted deposition;Al/Al2O3 bilayer coating;Corrosionresistance
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发布时间：2021-04-09 - 摘要：Improvement of oxidation properties of the ion-implanted GH903 alloy wasinvestigated by the slow positron beam analysis. Energy of Cr+ or Y+ ions was60keV and the implanted doses were 1×1015·cm-2（Y+）,1×1017·cm-2（Cr+）and 1×1015·cm-2（Y+）+1×1017·cm-2（Cr+）,respectively. Compared with the orginalsamples, the oxidizing weight-increment of the sample implanted by Cr+,Y+ and（Y++Cr+）ions were decreased 4.8%,24.2%and 32.3%, respectively.Mechenism ofthe modified oxidation is disscussed in terms of filling and annealing of defects in thenear-surface, chemical characteristics of the implanted elements and forming morecompact surface by ion implantation.关键词：GH903 alloy;Ion-implantation;Oxidation;Slow positron beam analysis
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发布时间：2021-04-09 - 摘要：The intermediate mass fragment measurements in the reaction 40Ar+159Tb at30MeV/u with an array of △E（Si）+E（BGO） telescopes were carried out . The resultsindicate that this detector array is suitable for the identification of intermediate massfragments.关键词：E（Si）+E（BGO） telescope array;Intermediate energy heavy ion reaction;Intermediate mass fragments
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发布时间：2021-04-09 - 摘要：The changes of photoelectronic characteristics for photodevices and MOS capacitors after proton or Υ- ray irradiation are investigated. The annealing effect of the samples at 150℃ and 200℃ after Υ- ray irradiation is also discussed. The photocurrent spectra of the Si photodevices measured with spectrophotometry in the range of Si spectral response have been used to understand the space distribution of damages in the devices induced by different irradiations.关键词：Photodevice;Photocurrent spectra;Irradiation effect;Space distribution
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发布时间：2021-04-09 - 摘要：The preparation of 188W- 188Re generator using alumina chromatography column was studied. The yield of 188Re from a generator with 10mL 0.9%NaCl as elution was 70%- 80% and stable for a three- month period. The elution curve of 188Re from alumina column was reproducible. The radionuclide purity, radiochemical purity, chemical purity and the breakthrough of 188 Re were satisfied.关键词：Tungsten- 188;Rhenium- 188;Alumina;Generator
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发布时间：2021-04-09 - 摘要：The type of sedimentary organtic matter is an important parameter in evaluating an oil or gas field. Since the coaventional organic geochemistry methods for determining the type meet unsurmountable difficulties when the maturity of organic matter is high, a new method to identify the type according to V and Ni contents in soluble organic matter based on NAA has been developed. Details of the methOd are introduced and an applied example is given关键词：Trace element;Sedimentary organic matter;NAA
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发布时间：2021-04-09 - 摘要：The high quality SOI（silicon on insulator） materials were prepared with highly selective and self-stopping full isolation by porous oxidized silicon（FIPOS） technology. The PMOSFETs with different channel lengths were fabricated by the 2 μm CMOS process on the SOI wafers and their total dose 60Co γ- ray radiation characterietics were studied. The reaults show that the devices remain functional after 5kGy（Si） dose radiation, but the threshold voltage has a significant shift. The main factor causing this shift is the radiation- induced trapped- oxide charge in the gate oxide layer. The devices with different channel lengths have similar radiation characteristics. After room- temperature annealing for several hours, the threshold voltage has a little back- shift.关键词：FIPOS;SOI material;PMOSFET;Total dose radiation
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发布时间：2021-04-09 - 摘要：The energy loss effect in the latent track etching process of PET films irradiated by 900MeV argon ions is discussed. The critical energy-Ioss rate （dE/dX）. which is characteristic of the material（PET） is also given. The bulk etching rate Vb and track etching rate Vt are obtained with different methods.关键词：PET latent track;Ar ion irradiation;Critical energy-loss rate;Etching rate
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发布时间：2021-04-09 - 摘要：The beam energy spectrum monitor for the Hefei 200MeV Linac is introduced. The monitor is composed of a magnetic analyzer, a fluorescent screen, an optic system, a linear photodiode array, a signal processing circuit, an oscilloscope and a CCD camera. The measurement result is given.关键词：Linac;Beam energy spectrum;Linear photodiode array
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发布时间：2021-04-09
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