The njLclear polarization of ^(8)Li produced by beam-foil interaction with a single carbon foil was measured.The sign of the polarization was also deter-mined,and it tuned out to be opposite to that of the atomic pola...The njLclear polarization of ^(8)Li produced by beam-foil interaction with a single carbon foil was measured.The sign of the polarization was also deter-mined,and it tuned out to be opposite to that of the atomic polarization predicted by electric density gradient model.展开更多
The dynamic Monte Carlo program including a bombardment-induced Gibb-sian segregation process was used to^calculate angular distributions of individual elements from 3putlcrcd Cuq^PIq^alloy in the Ar ion energy range ...The dynamic Monte Carlo program including a bombardment-induced Gibb-sian segregation process was used to^calculate angular distributions of individual elements from 3putlcrcd Cuq^PIq^alloy in the Ar ion energy range between 0.2 and 1.5ke V.Calculated results show that for each investigated incident energy,the angular distribution of the Pt element is more forward-pointed than that of the Cu one;the reason may be that different percentage of sputtered atoms(37-45% of Pt and 12-19% of Cu)come from beneath the topmost layer.展开更多
The average binding energy of the dineutron virtual state was derived from the correlative spectrum of two protons in ^(2)H(d,^(2)p)^(2)n reaction,and from the p-p coincidence measurement the value is estimated to be ...The average binding energy of the dineutron virtual state was derived from the correlative spectrum of two protons in ^(2)H(d,^(2)p)^(2)n reaction,and from the p-p coincidence measurement the value is estimated to be about 210keV.展开更多
The syntheses of N-Methyl-14C benzyl amine and N-Methyl-14C benzyl nitrosamine are reported. Specific activities were approximately 920 MBq/mmol. Chemical and radiochemical purity checked by HPLC were more than 95%.
The ~3H-labelled belladonna alkaloids obtained by catalysed exchange method with microwave excitation was investigated. The specific activities of the labelled products Were 16—32 TBq/mol. More than 90% labelled posi...The ~3H-labelled belladonna alkaloids obtained by catalysed exchange method with microwave excitation was investigated. The specific activities of the labelled products Were 16—32 TBq/mol. More than 90% labelled positions of these ~3H-tracers were on phenyl rings. The radiochemical purity and chemical purity of crude products were both in 75—80%.展开更多
The preparation of the human hair reference material and the steps taken to confirm its homogeneity and stability as well as its certificatipn are described. Certified values for 17 elements, which are of importance f...The preparation of the human hair reference material and the steps taken to confirm its homogeneity and stability as well as its certificatipn are described. Certified values for 17 elements, which are of importance for human health, and reference values for the other 13 elements are provided for this material.展开更多
A combined PIXE-RBS channeling measurement system to examine Ⅲ-Ⅴ compound semiconductors has been established. Preliminary results on studying Si+ and Te+ implanted GaAs have been presented and discussed.
Polyacetylene films were doped with FeCl3 and implanted with 30 k’eV K+ ions. Physical changes to the films were examined by a series of measurements, which include the four-probe test, infrared ray absorption and 2 ...Polyacetylene films were doped with FeCl3 and implanted with 30 k’eV K+ ions. Physical changes to the films were examined by a series of measurements, which include the four-probe test, infrared ray absorption and 2 MeV He+ particle elastic recoil dettection and Rutherford backscattering. The chemical dopants (Fe+++ and Cl-) were redistributed after the implantation and the different species (K+. Fe+++ and Cl-ions) formed p - n junctions at the implantation depths. The implanted films exhibited desirable Ⅰ-Ⅴ characteristics, with current densities as high as 600 mA/cm- at 3V and back - to - forward ratio of current over 300. The polymer diodes kept their behavior for over 60 days. Discussions on the results were given in detail.展开更多
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 ma...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.展开更多
This paper describes the scanning nuclear microprobe facilities established at the Shanghai Institute of Nuclear Research. The Russion quadruplet constructed with four magnetic quadrupolets is used for microbeam forma...This paper describes the scanning nuclear microprobe facilities established at the Shanghai Institute of Nuclear Research. The Russion quadruplet constructed with four magnetic quadrupolets is used for microbeam formation. The long focus of the lens makes the working distance long enough to accommodate the scanning coils and the detectors for PIXE, RBS, RFS, NRA and SE experiments. A 5 μm focussed beam is scanned continously by a pair of coils. A multiparameter multidetector data system for the nuclear microprobe is based on the idea of Total quantitative scanning analysis (TQSA) suggested by Melbourne University. A digital graphic displayer is a good substitute for an ordinary storage oscilloscope for on- line scanned area monitoring. The new microprobe meets high demands of biologists and geologists on applications.展开更多
In this paper, (2H- methyl) toluene was prepared by catalysed halogen- tritium substitution method from benzyl bromide, then it was nitrated to produce (8H- methyl) trinitrotoluene. The tritiated product was purified ...In this paper, (2H- methyl) toluene was prepared by catalysed halogen- tritium substitution method from benzyl bromide, then it was nitrated to produce (8H- 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 sudied in rats. The results showed that the toxicokinetics characteristics of TNT were quickly absorbed into the blood, Vd】2L/kg.h, long T1/2β 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 1,1- 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).展开更多
Proton elastic scattering at energies around 2.0 MeV was used to determine the concentration of oxygen in a Y-Ba-Cu-O compound, nitrogen in a TiN film on steel substrate, and carbon and oxygen in a thin Mylar film. Pr...Proton elastic scattering at energies around 2.0 MeV was used to determine the concentration of oxygen in a Y-Ba-Cu-O compound, nitrogen in a TiN film on steel substrate, and carbon and oxygen in a thin Mylar film. Proton scattering from light elements in this energy range exhibits non-Rutherford scattering cross section, which is enhanced by a factor of 4 to 7 relative to the Rutherford scattering cross section. Thus the sensitivity for the light element detection is considerably larger than that obtained by He^+ ion scattering. Quantitative analysis by proton scattering is discussed and compared with other methods.展开更多
A copper based binary alloy containing 16.9 at % lithium has been bombarded with deuterium ions in energy range of 400 eV to 2 keV at the incidence angles of 70° and 80° away from the surface normal. The spu...A copper based binary alloy containing 16.9 at % lithium has been bombarded with deuterium ions in energy range of 400 eV to 2 keV at the incidence angles of 70° and 80° away from the surface normal. The sputtered flux was condensed on Al- strips arranged arround the target in a cylindrical cup. 1.5 MeV proton backscattering and nuclear reaction 7Li(p, α)4He were used to detect the collected atoms of Cu and Li simultaneously. The angular distribution of sputtered atoms has been shown to be different for two components and strongly anisotropic for the grazing incidence. According to direct knock-on sputtering model and the experimental results the angle for the maximum differential sputtering yield is dependent on the incidence angle α, the bombarding energy E, the energy transfer factor γ= 4M1M2/(M1+ M2)2 and the surface binding energy U. With the assumption that the sputtered particles are diffracted by a planar barrier the surface binding energies of 2.3 eV for the Li component and 3.0 eV for the Cu component have been determined by fitting the measured angles of preferred ejection to the direct knock-on sputtering model, and the results agree well with a pair-binding model.展开更多
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....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.展开更多
The concentrations of 18 elements in subcellular fractions of human liver were determined by combining differential centrifugation and INAA. Samples of human liver were homogenized in a buffer. The homogenate was sepa...The concentrations of 18 elements in subcellular fractions of human liver were determined by combining differential centrifugation and INAA. Samples of human liver were homogenized in a buffer. The homogenate was separated into nuclei, mitochondrial, lysosomal, microsomal and cytosol fractions by successive differential centrifugation. Biological standard reference materials were used to evaluate the accuracy of the INAA method, and the results agree with the certified values. Element levels in subcellular fractions of human liver were discussed.展开更多
The synthesis of 3, 4-dihydroxy- 6- bromo- phenyl- L- alanine (6- Br- L- dopa ), preparation of 3,4-dihydroxy-6-[ Br] bromo-phenyl-L-alanine(6-77 Br-bromo-L-dopa) and its distribution study in mouse brain are describe...The synthesis of 3, 4-dihydroxy- 6- bromo- phenyl- L- alanine (6- Br- L- dopa ), preparation of 3,4-dihydroxy-6-[ Br] bromo-phenyl-L-alanine(6-77 Br-bromo-L-dopa) and its distribution study in mouse brain are described. The radiochemical yield and radiochemical purity of 6- Br-bromo-L-dopa were 8.5 % and 93 %, respectively. Its distribution in mouse brain after one hour injection indicates that it does pass blood brain barrier. The ratio of uptake in striatum to that in cerebellum was 2.45±0.12. The results appeared that 6- Br-bromo-L-dopa could be used as brain tracer for visualizing dopamine-containing brain structures by using single photon tomography.展开更多
Two new systems have been presented for the extraction separation of <sup>68</sup>Ga from irradiated Ga<sub>2</sub>O<sub>3</sub> target after proton bombardment. It could avoid the ...Two new systems have been presented for the extraction separation of <sup>68</sup>Ga from irradiated Ga<sub>2</sub>O<sub>3</sub> target after proton bombardment. It could avoid the loss of <sup>68</sup>GeCl<sub>4</sub> during the processing and storage, resulting a stable <sup>68</sup>Ge source.展开更多
The reaction 11B(p,α) 8Be was used to profile boron concentration in silicide. The energy of incident proton of 2.4 MeV was selected. The samples were Ti silicide implanted with 80 keV and 230 keV BF2. The experiment...The reaction 11B(p,α) 8Be was used to profile boron concentration in silicide. The energy of incident proton of 2.4 MeV was selected. The samples were Ti silicide implanted with 80 keV and 230 keV BF2. The experimental results indicate that the behaviour of boron is different from that of fluorine during silicide formation.展开更多
Elemental profiles of brain tumour tissues from 15 male patients of astrocytomas (grade Ⅰ-Ⅲ) and normal human brain tissues of 23 male age matched autopsies as controls have been studied by INAA. A total of 18 eleme...Elemental profiles of brain tumour tissues from 15 male patients of astrocytomas (grade Ⅰ-Ⅲ) and normal human brain tissues of 23 male age matched autopsies as controls have been studied by INAA. A total of 18 elements Se, Na, K, Br, Cl, Mn, Mg. S, Ca, Cu, Hg, Cr, Fe, Rb, Zn, Co, Sc and P has been determined for this purpose. The analytical results showed that compared with the normal brain tissues, concentrations of Ca, Fe, Cu, Zn, Mn, Br and Sc were significantly higher in tumour tissues and that of Rb, K and P were lower while no differences for contents of Mg, S, Cr, Na and Cl were observed. A negative correlation between P and Ca in malignant and normal brain tissues was observed.展开更多
By using the Hamiltonian included in the static Su-Schrieffer-Heeger model and the Coulomb potential of solitons and ions,we investigated the insulator-metal transition mechanism in Na-doped trans-polyacetylene and ga...By using the Hamiltonian included in the static Su-Schrieffer-Heeger model and the Coulomb potential of solitons and ions,we investigated the insulator-metal transition mechanism in Na-doped trans-polyacetylene and gave the dependence of the Pauli susceptibility for 8.33%Na doping on the various widths and arrangements of the solitons.展开更多
基金supported by the National Natural Science Foundation of China.
文摘The njLclear polarization of ^(8)Li produced by beam-foil interaction with a single carbon foil was measured.The sign of the polarization was also deter-mined,and it tuned out to be opposite to that of the atomic polarization predicted by electric density gradient model.
文摘The dynamic Monte Carlo program including a bombardment-induced Gibb-sian segregation process was used to^calculate angular distributions of individual elements from 3putlcrcd Cuq^PIq^alloy in the Ar ion energy range between 0.2 and 1.5ke V.Calculated results show that for each investigated incident energy,the angular distribution of the Pt element is more forward-pointed than that of the Cu one;the reason may be that different percentage of sputtered atoms(37-45% of Pt and 12-19% of Cu)come from beneath the topmost layer.
文摘The average binding energy of the dineutron virtual state was derived from the correlative spectrum of two protons in ^(2)H(d,^(2)p)^(2)n reaction,and from the p-p coincidence measurement the value is estimated to be about 210keV.
文摘The syntheses of N-Methyl-14C benzyl amine and N-Methyl-14C benzyl nitrosamine are reported. Specific activities were approximately 920 MBq/mmol. Chemical and radiochemical purity checked by HPLC were more than 95%.
基金The Project Supported by National Natural Science Foundation of China
文摘The ~3H-labelled belladonna alkaloids obtained by catalysed exchange method with microwave excitation was investigated. The specific activities of the labelled products Were 16—32 TBq/mol. More than 90% labelled positions of these ~3H-tracers were on phenyl rings. The radiochemical purity and chemical purity of crude products were both in 75—80%.
基金The Project Supported by National Natural Science Foundation of China
文摘The preparation of the human hair reference material and the steps taken to confirm its homogeneity and stability as well as its certificatipn are described. Certified values for 17 elements, which are of importance for human health, and reference values for the other 13 elements are provided for this material.
文摘A combined PIXE-RBS channeling measurement system to examine Ⅲ-Ⅴ compound semiconductors has been established. Preliminary results on studying Si+ and Te+ implanted GaAs have been presented and discussed.
基金The Project Supported by National Natural Science Foundation of China, Contract No.1860193
文摘Polyacetylene films were doped with FeCl3 and implanted with 30 k’eV K+ ions. Physical changes to the films were examined by a series of measurements, which include the four-probe test, infrared ray absorption and 2 MeV He+ particle elastic recoil dettection and Rutherford backscattering. The chemical dopants (Fe+++ and Cl-) were redistributed after the implantation and the different species (K+. Fe+++ and Cl-ions) formed p - n junctions at the implantation depths. The implanted films exhibited desirable Ⅰ-Ⅴ characteristics, with current densities as high as 600 mA/cm- at 3V and back - to - forward ratio of current over 300. The polymer diodes kept their behavior for over 60 days. Discussions on the results were given in detail.
文摘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.
基金The Project Supported by the Foundation of Academic Sinica
文摘This paper describes the scanning nuclear microprobe facilities established at the Shanghai Institute of Nuclear Research. The Russion quadruplet constructed with four magnetic quadrupolets is used for microbeam formation. The long focus of the lens makes the working distance long enough to accommodate the scanning coils and the detectors for PIXE, RBS, RFS, NRA and SE experiments. A 5 μm focussed beam is scanned continously by a pair of coils. A multiparameter multidetector data system for the nuclear microprobe is based on the idea of Total quantitative scanning analysis (TQSA) suggested by Melbourne University. A digital graphic displayer is a good substitute for an ordinary storage oscilloscope for on- line scanned area monitoring. The new microprobe meets high demands of biologists and geologists on applications.
文摘In this paper, (2H- methyl) toluene was prepared by catalysed halogen- tritium substitution method from benzyl bromide, then it was nitrated to produce (8H- 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 sudied in rats. The results showed that the toxicokinetics characteristics of TNT were quickly absorbed into the blood, Vd】2L/kg.h, long T1/2β 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 1,1- 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).
文摘Proton elastic scattering at energies around 2.0 MeV was used to determine the concentration of oxygen in a Y-Ba-Cu-O compound, nitrogen in a TiN film on steel substrate, and carbon and oxygen in a thin Mylar film. Proton scattering from light elements in this energy range exhibits non-Rutherford scattering cross section, which is enhanced by a factor of 4 to 7 relative to the Rutherford scattering cross section. Thus the sensitivity for the light element detection is considerably larger than that obtained by He^+ ion scattering. Quantitative analysis by proton scattering is discussed and compared with other methods.
文摘A copper based binary alloy containing 16.9 at % lithium has been bombarded with deuterium ions in energy range of 400 eV to 2 keV at the incidence angles of 70° and 80° away from the surface normal. The sputtered flux was condensed on Al- strips arranged arround the target in a cylindrical cup. 1.5 MeV proton backscattering and nuclear reaction 7Li(p, α)4He were used to detect the collected atoms of Cu and Li simultaneously. The angular distribution of sputtered atoms has been shown to be different for two components and strongly anisotropic for the grazing incidence. According to direct knock-on sputtering model and the experimental results the angle for the maximum differential sputtering yield is dependent on the incidence angle α, the bombarding energy E, the energy transfer factor γ= 4M1M2/(M1+ M2)2 and the surface binding energy U. With the assumption that the sputtered particles are diffracted by a planar barrier the surface binding energies of 2.3 eV for the Li component and 3.0 eV for the Cu component have been determined by fitting the measured angles of preferred ejection to the direct knock-on sputtering model, and the results agree well with a pair-binding model.
文摘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.
文摘The concentrations of 18 elements in subcellular fractions of human liver were determined by combining differential centrifugation and INAA. Samples of human liver were homogenized in a buffer. The homogenate was separated into nuclei, mitochondrial, lysosomal, microsomal and cytosol fractions by successive differential centrifugation. Biological standard reference materials were used to evaluate the accuracy of the INAA method, and the results agree with the certified values. Element levels in subcellular fractions of human liver were discussed.
文摘The synthesis of 3, 4-dihydroxy- 6- bromo- phenyl- L- alanine (6- Br- L- dopa ), preparation of 3,4-dihydroxy-6-[ Br] bromo-phenyl-L-alanine(6-77 Br-bromo-L-dopa) and its distribution study in mouse brain are described. The radiochemical yield and radiochemical purity of 6- Br-bromo-L-dopa were 8.5 % and 93 %, respectively. Its distribution in mouse brain after one hour injection indicates that it does pass blood brain barrier. The ratio of uptake in striatum to that in cerebellum was 2.45±0.12. The results appeared that 6- Br-bromo-L-dopa could be used as brain tracer for visualizing dopamine-containing brain structures by using single photon tomography.
文摘Two new systems have been presented for the extraction separation of <sup>68</sup>Ga from irradiated Ga<sub>2</sub>O<sub>3</sub> target after proton bombardment. It could avoid the loss of <sup>68</sup>GeCl<sub>4</sub> during the processing and storage, resulting a stable <sup>68</sup>Ge source.
文摘The reaction 11B(p,α) 8Be was used to profile boron concentration in silicide. The energy of incident proton of 2.4 MeV was selected. The samples were Ti silicide implanted with 80 keV and 230 keV BF2. The experimental results indicate that the behaviour of boron is different from that of fluorine during silicide formation.
文摘Elemental profiles of brain tumour tissues from 15 male patients of astrocytomas (grade Ⅰ-Ⅲ) and normal human brain tissues of 23 male age matched autopsies as controls have been studied by INAA. A total of 18 elements Se, Na, K, Br, Cl, Mn, Mg. S, Ca, Cu, Hg, Cr, Fe, Rb, Zn, Co, Sc and P has been determined for this purpose. The analytical results showed that compared with the normal brain tissues, concentrations of Ca, Fe, Cu, Zn, Mn, Br and Sc were significantly higher in tumour tissues and that of Rb, K and P were lower while no differences for contents of Mg, S, Cr, Na and Cl were observed. A negative correlation between P and Ca in malignant and normal brain tissues was observed.
文摘By using the Hamiltonian included in the static Su-Schrieffer-Heeger model and the Coulomb potential of solitons and ions,we investigated the insulator-metal transition mechanism in Na-doped trans-polyacetylene and gave the dependence of the Pauli susceptibility for 8.33%Na doping on the various widths and arrangements of the solitons.
