最新刊期
卷 0 ， 期 0 ， 2020
- 摘要：The creep damage in 12Cr1MoV steel has been studied by the positron lifetime measurements. The lifetime spectra were analyzed into three components. The mean lifetime τ, defection lifetime τ2 and its intensity I2 increased with the increasing creep damage rate D. The saturation of positron annihilation parameters was not observed, which was a feature different from the positron studies on deformation and fatigue experiments of metals and alloys. When creep damage rate D> 1%, τ2 and τ3 increased rapidly and I2 reached about 10%. These characteristics strongly suggest that the vacancy clusters were formed from vacancies in the creep process, and finally the voids were formed.
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发布时间：2021-04-09 - 摘要：Positron annihilation spectroscopy and thermal release of hydrogen have been employed to study the 40CrNiMo high strength steel in seawater corrosion fatigue process before fracture. It was found that dislocations, vacancy clusters or microvoids and grain boundaries were the trapping seats for hydrogen, the amount of hydrogen trapped by these defects increased with corrosion fatigue duration. Dislocation multiplication and the increase of number and size of vacancy clusters or microvoids due to interaction between hydrogen and defects were observed. In addition, interaction energy between hydrogen and both dislocation and grain boundary, especialy the latter, decreased with corrosion fatigue duration, which may be favourable to promote hydrogen movement and the pre- cracking fracture along grain boundaries.
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发布时间：2021-04-09 - 摘要：A grey pottery figure manufactured in the Western- Han Dynasty and the clay gathered from the same site of Beidongshan near Xuzhou have been studied by X- ray diffraction, X- ray fluorescence and Mossbauer spectroscopy. They were simultaneously fired under the same conditions in different atmospheres at various temperatures. The information on original firing atmosphere and temperature as well as its provenance can be inferred from the method of pottery retiring and clay firing. The original firing temperatures deduced from both of them are in good self- agreement. It is found that the values of Mossbauer parameters for the unrefired pottery figure are approximately the same as those for the clay fired at 950℃ for five hours in a reduced atmosphere. The XRF analysis confirmed that the locality of this pottery figure was somewhere near Beidongshan.
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发布时间：2021-04-09 - 摘要：The collisional interaction of heavy- water clusters with a TiD target has been studied. Deuteron spectra have been determined by an analytical method and the molecular dynamics simulation. It is shown that the maximum deuteron energy can exceed six times of their inital energy due to the wide- angle scattering between deuterons and moving heavy atoms.
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发布时间：2021-04-09 - 摘要：Effective measures have been adopted for increasing the negative ion beam intensity and decreasing the emittance of the Model 860A high intensity sputter source through enhancing the cathode voltage and rebuilding a focusing geometry electrode system. By using a Ta sheet spherical geometry ionizer the sputtering region has been narrowed down to a diameter of 0.75mm. Three porcelain rods replacing the original cathode insulator make the target voltage reach 10kV. The negative ion beam intensity of some species has increased by 300% and the transmission efficiency is improved. These measures have improved operation conditions of the 2×1.7MV Tandetron for large dose high energy ion implatation.
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发布时间：2021-04-09 - 摘要：A windowless position sensitive detector called image intensifier is described. It consists of a photocathode, a microchannel plate and a fluorescent screen, coupled by optical fiber to a 512 element self- scanning photodiode array. The performance of the image intensifier has been measured by using soft X- ray （1.7-7nm）. It can be used for a detector on the soft X- ray bent crystal spectrometer.
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发布时间：2021-04-09 - 摘要：A Hall multiprobe facility for measuring accelerator magnetic field was described. It consisted of a long arm with 3 thermostats containing totally 58 Hall probes, a calibration system of magnetic field with high accuracy, and an automatic data acquisition system. Location, temperature constant and calibration of the Hall probes, and data acquisition and processing were described respectively. The significance of stability of Hall probes for the multiprobe facility was presented. The facility has been used in the construction of HIRFL （Heavy Ion Research Facility Lanzhou）. It was shown that the requirement for measuring the accelerator magnetic field could he satisfied.
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发布时间：2021-04-09 - 摘要：The influence of temperature change on the high pressure ionization chamber and its A- F converter output circuits is studied. The experimental result is useful for the design of these devices.
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发布时间：2021-04-09 - 摘要：The cyclotron in SINR has been used as a cyclotron mass spectrometer for tritium dating. The gas introduced into the ion source was 3H- containing hydrogen which collected from electrolysis of water samples and mixed with a certain amount of air in which trace 3He was used as a reference. 3H and 3He ions were accelerated simultaneously. The separation and identification of these two ion species was made by a combination of silicon detector telescope and aluminium absorption foil.
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发布时间：2021-04-09 - 摘要：The experiment was done at 60℃ with KOH as etching solution. The results showed that the lower the alpha particle’s energy, the earlier the developing time of track. When the energy of particle was less than 70keV, the track could not be developed. The track size increased with increasing etching time. It changed rapidly with energy in the range from 1 to 4 MeV. As for energies was higher than 4MeV, the change decreased gradually. If the incident angle of alpha particle was greater than 40?, the actual incident angle would coincide the calculated value. But there was a great difference in the two angle values for the incident angle less than 40°.
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发布时间：2021-04-09 - 摘要：316L stainless steel samples irradiated with 54MeV carbon ions and significant changes in structure and micro parameters of the samples were observed. Mossbauer effect and X- ray diffraction method were used to study phase transformation in the samples before and after irradiation. The distribution of carbon atoms and the type of phase transformation are discussed.
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发布时间：2021-04-09 - 摘要：A simulation method of resonance reaction yield curve is reported. The boron depth profiles in boron doped amorphous silicon- carbon films prepared in a rf glow discharge at various substrate temperatures were studied by using 11B（p, a ）8Be at Ep = 163keV resonance reaction and simulating the reaction yield curve. Some of the characteristics of boron depth profile in these films were presented. The results show that the simulation of resonance reaction yield curve should be effective for improving the depth resolution and simplifying the analysis method of boron depth profiling and useful for the research of boron doped amorphous films.
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发布时间：2021-04-09 -
Blood lipid metabolism disturbance of hyperinsulinemia and its relationship with chromium deficiency
摘要：The levels of blood lipids and serum chromium in 143 patients with hyperinsulinemia were determined. The results showed that Tc, Tg, VLDL- C and APO- B of the patients were higher but HDL- C was lower than the control group. The mean value of serum chromium was apparently decreased. The relationship between blood lipid metabolism disturbance of hyperinsulinemia and chromium deficiency has been discussed.- 8
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发布时间：2021-04-09
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