The Mn component of stainless steel 304 LN has been found to be severely depleted in the surface layer during heating at the temperature 1200 K. The surface concentrations of Mn were reduced by about 2-3 orders of magnitude in comparison with the bulk value, as was revealed by a secondary ion mass spectroscopy (SIMS) system. And the Mn concentration gradient in the surface layer was examined, too, by SIMS. Massive preferential losses of Mn have been determined by using the catcher technique and proton induced X- ray emission (PIXE). A theoretical model has been proposed for calculating the surface concentration changes for a component in an alloy under heating. A comparison shows a good agreement between the calculation and experimental results from SIMS and catcher technique.

Non - focused ion beams may be employed to investigate the surface profile and the shape of microscopic objects or periodic surfaces by using the known stopping powers of ions in solids. The energy spectra of the scattered or reaction ions are recorded as a function of the angles between the beam, the object and the detector, and of the energy of incident ions. The shape parameters may then be determined using computer codes. Presented also are the typical experimental results.

Particle induced X- ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) have been used extensively for analytical purpose because of their quantitative accuracy, reliability, simplicity and capability of non- destructive and multielement analysis. When these techniques are combined with a scanning microbeam system and a data acquisition system, three dimensional distribution of elemental composition can be displayed. Samples analyzed so far at Fudan University include a microelectronic circuit and some biological and archaeological samples. The PIXE and RBS spectra and the secondary electron images have been measured.

In this paper, an experimental method was described for measuring very slight wear of polymer by using neutron activation analysis (NAA). By means of adopting appropriate neutron flux suitable experimental parameters and measuring technique, the method was performed under the condition without any effect upon the mechanical properties of wearing. The sensitivity of the wear measurements reached the order of magnitude of 10^-7g for engineering plastics containing about 1 wt% of zinc. The comparison could be made rapidly between different materials with different resistance to wear. The results were free from the influence of vibration of test systems, elastic deformation of materials, media and moisture absorption, and etc. Combined with autoradiograph, the present technique can be used to investigate the backtransfer of ground debris of metallic fillers from the counter part to the specimen. A multifunctional plane wear testing machine was set up for obtaining wear data and friction coefficient. The present work provides a new, rapid and sensitive measuring technique and also a screening method for the wear of polymers.

Small discs of type HR- 1 austenitic steel (OCr₁₇Ni₁₄MnMo) have been irradiated with 30-170 keV He⁺ for doses 10¹⁶- 1×10¹⁸/cm² at 300K. 2.5 MeV enhanced proton backscattering, TEM, SEM and CEMS are used to investigate the He trapping, bubble structures and the phase stability. It is found that a maximum He concentration of ~28. at. % was obtained after implantation with 70 keV He⁺ at a dose just below critical. The micro- Vickers hardnesses of irradiated layers decrease with increasing dose, particularly when dense bubbles formed. The isomer shift of CEMS increases in the negative direction after irradiation. The austenite is believed to be stable against radiation induced martensitic transformation.

The resonance nuclear elastic scattering ¹⁶O(α ,α ) ¹⁶O at 3.045 MeV has been used to profile oxygen distributions in SOI material synthesised by SIMOX technique. The buried SiO₂ layer is produced by 1.8 × 10¹⁸ at./cm² oxygen implantation at 500℃ and high temperature annealing at 1405℃ for 30 min. The experimental results show that after annealing sharp SiO₂/Si interfaces at both sides of buried layer and a very good quality of top Si single crystal layer are obtained. The formation mechanism of the buried layer, correlated with SiO₂ precipitates and dissolution, radiation enhanced diffusion and epitaxial growth, is discussed.

In this paper we try to study the retentive peculiarity of soluble enriched uranium UO₂F₂ in subcellular level by electron microscopic autoradiography. The early dynamic accumulation of radioactivity in the body showed that enriched uranium UO₂F₂ was chiefly localized in kidney, especially accumulated in epicyte of kidney near- convoluted tubule. In liver cells, enriched uranium UO₂F₂ at first deposited in the nucleus and the cytoplasm, then accumulated in mitochondria selectively and lysosome as well. The electron microscopic autoradiographic study showed that the dynamic retention of radioactivity of enriched uranium UO₂F₂ in skeleton rose steadily throughout the exposure. Enriched uranium UO₂F₂ chiefly deposited in nucleus and mitochondria of the osteoblast as well as osteoclast.

Residues of ¹⁴C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91 µ g/g and 7.78 µ g/g (LRE) and 5.04 µ g/g and 17.29 µ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined.

The lead and barium contents in sixteen archaeological bone samples from 10 persons buried in Dalsby, Sweden, were determined by means of X- ray fluorescence analysis using two ⁵⁷Co sources for excitation and a planar Ge detector for registration of the X- rays. The lead concentrations were found to be less than 168μ g/g, and the barium concentrations were in the range of 15- 97μ g/g.

Results are reported on a research for the radioactive level in the investigation region and the control region around the Xinjiang Nuclear Testing Site from 1982 to 1987. There are no significant differences on the land γ radiation level, nor in the radioactive level in the soil, food and water between the two regions. The distribution and transfer of ⁹⁰Sr, ¹³⁷Cs and Pu in various kinds of soil are also discussed. It is estimated that the effective dose equivalent of radiation. undergone by the residents around the Testing Site is only 2.9% of that of natural radiation taken yearly by people in normal areas.

In this paper, (³H- methyl) toluene was prepared by catalysed halogen- tritium substitution method from benzyl bromide, then it was nitrated to produce (³H- methyl) trinitrotoluene. The tritiated product was purified by thin- layer chromatography. At last, the pure ³H- TNT was obtained with specific radioactivity of 3.77 GBq/mmol. Radiochemical purity was over 98% and the ultraviolet absorption spectrum of tritiated TNT was conformed with that of standard sample. Using ³H- TNT as a tracer, its toxicokinetics was studied in rats. The results showed that the toxicokinetics characteristics of TNT were quickly absorbed into the blood, V_d > 2L/kg.h, long T_1/2 β and fixed accumulation with four routes of administration, TNT and its metabolites were mainly excreted by the urine. The half- life of TNT in the urine were 11- 24h. A trace of radioactivity of ³H- TNT and its metabolites could be detected in the urine on 7th day after administration (9.25 × 10⁶Bq/kg).