[en] The radiation damage on GaAs is investigated during transmutation doping. Ge, as amphoteric impurity, is introduced and its defect configuration as well as thermal behaviors have an effect on the electrical properties of GaAs during thermal recovery

[en] The authors provided a personal computer program to simulate and analysis Rutherford Backscattering spectra. The algorithms of the simulation program assume a uniform sample and use a mathematical model that the sample is considered to be made up of many sub-layers. Detector resolution can be simulated by convolving the ideal spectrum with a Gaussian. The effects of straggling are difficult to compute efficiently. The Simulation program which has been proved to be precise is refitted to be a generator of RBS (GENRBS), and creates a set of standard data to fit the experimental data. The fitting parameters are the unknown quantitative results. A damping item and a parabola interpolation algorithm are added to the fitting program to increase the reliability and accuracy. The two programs have applied to backscattering experiments and the results have conformed to the experimental values

[en] An experiment to search for stable superheavy nuclearites and quark nuggets in different meteorites has been performed using the Rutherford backscattering technique. An upper limit of the relative concentration of nuclearites with Z∼100 and A∼1000 in the meteorite samples of about 2 atomic ppm is obtained

[en] As variable energy monochromatic sources both synchrotron radiation monochromatic light and proton induced X-ray emission were used to study X-ray fluorescence of K, Ca, Ti light elements. The results indicate that this method not only reduces the bremsstrahlung background but also eliminates the interference with some other elements by selecting appropriate exciting energy. Thus the analytic sensitivity of K, Ca, Ti elements are considerably improved

[en] An experiment to search for stable superheavy nuclearites and quark nuggets in different meteorites has been performed using the Rutherford backscattering technique. The upper limit of the relative concentration of nuclearites with Z ∼ 100 A ∼ 1000 in the meteorite samples about 2 ppm is obtained

No abstract available

[en] Marine aerosol from the western Pacific were collected by two types of samplers during a cruise from Nanhai of China through the west of Philippines to the equatorial and to the north-eastern of Solomon Archipelago. Collected samples were analyzed by PIXE. The data gave aerosol characteristics over the western Pacific, including concentrations, enrichments and mass size distributions of detected elements, and possible sources of these elements were specially researched. The result indicates that Al, Si and Fe were associated with soil particles; Cl, Br, K, Ca and S showed characteristics of the sea-salt origin; and Cu, Zn, and Pb were due to pollution from long-range transport of continental aerosol. We have also made comparison with data obtained in earlier studies over other regions of the Pacific. (author)

[en] A charge-division, position-sensitive proportional counter with single anode was developed for high-resolution low-energy X-ray analysis. Its efficiency was estimated from an approximate formula and its position resolution was measured by ⁵⁵Fe source with the width of 50 μm(x). The efficiency changes from 65% to 25% in the energy range (4-6.5 keV) of interest and the position resolution is about 0.55 mm. And two samples of application of PSS constructed by PSPC are also introduced. (authors)

[en] The author briefly presented the noise in various readout methods and low-noise preamplifier used in position sensitive detectors. Two preamplifiers used in PSPC have been made and they have obtained better identical performances: the noise < 1 mV and its width of spectrum (FWHM) ≅ 3 channel

[en] Proton-induced X-ray emission (PIXE) technique was used to measure concentration of trace elements in marine rain water over the western Pacific Ocean. The calculation of enrichment factors of various elements indicated that crustal and pollutant elements came mainly from long distance transportation of soil-dust particles and anthropogenic pollutant, respectively