A unified plasma sheath model and its potential equation are proposed. Any higher-order approximation analytical solutions for the unified plasma sheath potential equation are derived by double decomposition method.
Vol.9, No.4
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1998
4
Research article 01 Nov 1998
Fang Jin-Qing
keyword：Plasma sheath；Double decomposition method；Approximation analytical solution；
Research article 01 Nov 1998
Li Yan,，Huang Wen-Da,，Shi Shuang-Hui,，Gu Jia-Hui,，Liu Jing-Yi,，Yu Xiao-Han,，Zeng Ji-Ping
The decay of 76Br has been investigated for further study of the 76Se levels. Gamma ray singles were measured with HpGe-NaI Compton-suppressed spectrometer. Coincidence spectra were collected with two HpGe detectors coupled to a three-parameter system. There were 138 γ-rays observed, and 120 of these were fitted into 46 levels in 76Se. 37 γ-rays and 15 new energy levels were found for the first time.
keyword：γ-ray；Energy levels；Transition；Coincidence；
Research article 01 Nov 1998
He Ze-Jun，Zhang Jia-Ju，Liu Bo
Considered the Drell-Yan background in the intermediate invariant mass region, the dilepton production in an expanding hot baryon-rich quark-gluon matter fire-cylinder has been studied based on a previously established relativistic hydrodynamic model. It is found that with increasing the rapidity the dilepton yield is strongly suppressed. Such a characteristic, signaling the formation of the baryon-rich quark-gluon matter, can be tested in future experiments at Brookhaven and CERN.
keyword：Ultrarelativistic heavy-ion collisions；Quark-gluon matter；Dilepton production；
Research article 01 Nov 1998
Qian Wan-Yan，Cai Xu，Zhou Dai-Cui
Three new nuclear emulsion techniques used for measuring emission angles of charged particles in central events at ultra-high evergy heavy-ion collisions are fully described.
keyword：Nuclear emulsion detector；Heavy ion collisions；Multiparticle production；
Research article 01 Nov 1998
Xue Jian-Ming，Wang Yu-Gang，Lu Xi-Ting，Yan Sha，Chen Jiang，Zhao Wei-Jiang
F2+ beam with 3 MeV is used to irradiate thin biological samples (onion inner surface membrane and kidney bean coat) in the transmission measurement, its current density is 400~800 nA/cm2. Results show that the onion samples can be broken up quickly under ion irradiating; as to kidney bean samples, about 60% of the implanted ions penetrate the samples, most of them lose part of their energy, fewer ions are found to be able to transmit through the sample without energy loss. SEM experiments are carried out to study sample's damage induced by the ions irradiation.
keyword：Ion implantation；Biological sample；Transmission measurement；
Research article 01 Nov 1998
Prevenslik T V
Sonoluminescence (SL) observed in the cavitation of water may be explained by the Planck theory of SL that treats the bubbles as collapsing miniature masers having optical waves standing in resonance with the dimensions of bubble cavity. Microwaves are created from the Planck energy of the standing waves provided the bubble wall may be treated as a perfect blackbody surface. In the ultraviolet, liquid H2O is strongly absorbent and the bubble approaches a Planck blackbody enclosure. The micrwaves are created at frequencies proportional to the bubble collapse velocity and are absorbed by the dipoles of the H2O and other bubble wall molecules. Intense electric fields develop as the liquid H2O bubble wall undergoes dielectric polarization. By this theory, free electrons are created in SL as the electric fields breakdown; the presence of free electrons is required if any magnetic field effect is to be observed in SL. Both local and global magnetic effects on SL are described. The local effect is based on the magnetic pressure due to the electrons moving as currents inside the bubble. The global effect is an accumulation of local effects at the voids throughout the liquid H2O causing a reduction in the bulk modulus. Numerical solutions of the Rayleigh-Plesset (R-P) equation are presented that show the effect of applied magnetic field on SL to be the global effect causing a reduction in the bulk modulus. Consistent with the Planck theory of SL, the R-P simulations show the suppression of SL intensity with magnetic field to be parabolic and the SL intensity to be linear with collapse velocity.
keyword：Sonoluminescence；Maser；Magnetic fields；
Research article 01 Nov 1998
Wang Wei-Da，Zhou Zhi-Xin，Xia Jun-Ding，Leung P L，Stokes M J
In the fine-grain TL dating the full α dose must be converted into the equivalent β dose. The conversion is finished by Keff-value, which is an effective α effectiveness. But the Keff can not be measured directly for each sample and only the external radiative efficiency K3.7 can be measured. In order to obtain the Keff a special study for the conversion factor of Keff to K3.7 has been made using the ultrathin TLD. The results show that the conversion factor of the TLD for archaeological samples is 0.847, which is in agrcement with calculated value 0.85.
keyword：TL dating；Alpha efficiency；keff；K3.7；Conversion factor；
Research article 01 Nov 1998
Cai Yan-Huang，Zhu Zhi-Yuan
A microscopic semiclassical Vlasov equation approach is used to investigate the dipole giant resonances of spherical cluster Na14. The main strength distributions of collective response function are located around 2eV region, with a fair agreement with the experiment ones. The results are quite independent of the choice of parameters of the mean field.
keyword：Metal cluster；Vlasov equation；Dipole giant resonance；
Research article 01 Nov 1998
Zhou Guang-Ming，Wei Zeng-Quan，Li Wen-Jian，Gao Qing-Xiang，He Jing，Li Qiang，Wang Jü-Fang
The yield of DNA double-strand breaks (DSBs) is sure to be influenced by the environment around DNA molecule. Inverse pulsed-field gel electrophoresis (PIGE) has been applied to compare the sensitivity of B16 cells and their DNA in DSBs induced by 75 MeV/u 16O8+ beam. Results show that the percentages of DNA released from the plug(PR) in both kinds of the samples increase with the dose and approach a similar quasi-threshold of about 81%. A simple new equation was presented to calculate the break level of DNA molecules. Within a certain dose, the relationship between the break level and the dose is linear. The yield of DSBs in deproteinized DNA was 1.11 DSBs/100 Mbp/Gy, while that in intact cells was 0.60DSBs/100Mbp/Gy. It is testified that deproteinized DNA is more sensitive to oxygen ions irradiation than intact cells.
keyword：DNA double-strand breaks；75 MeV/u 16O8+ beam；Melanomas cells；
Research article 01 Nov 1998
An Zhu
When there exist many light elements in a sample or the sample is thick, a reliable (d,p) reaction analysis cannot be often obtained due to the interference of particle groups corresponding to different elements and even different energy levels of an element. Therefore, (d,pγ) coincidence technique is tried. By measuring a charged particle(proton) group in coincidence with its accompanying gamma rays, the background can be greatly suppressed and the interference can be effectively eliminated.
keyword：Deuteron-induced nuclear reactions；Coincidence measurement；Depth profiling analysis；
Research article 01 Nov 1998
Yang Yan-Zhao，Sun Si-Xiu，Bao Bo-Rong
The mechanism of extraction uranium(VI) with di(2-ethylhexyl) sulfoxide (DEHSO) from aqueous nitric acid media has been studied. The influence of the concentrations of nitric acid, extractant, salting-out agent, temperature and complex anions (C2O42-) on the distribution ratio was studied.
keyword：Di(2-ethylhexyl) sulfoxide；Solvent extraction；Uranium(VI)；
Research article 01 Nov 1998
Wu Chun-Ying,，Ji Shu-Ren,，Fang Ping
A new method for the preparation of p-iodophenyl pentadecanoic acid (IPPA) has been developed. The synthesis are described, and physical properties of IPPA are characterized by IR, 1HNMR, elementary analysis and MS. 125I-IPPA can be easily prepared by two methods: direct labeling and solid-phase iodo-exchange labeling, and the yields of labeling are 80% and 65%, respectively. The radiochemical purities are higher than 98% after being extracted with chloroform and hexane.
keyword：p-iodophenyl pentadecanoic acid；Fatty acid；Synthesis；125I-IPPA；125I-labeling；
Research article 01 Nov 1998
Li Bin，Zhou Mei-Ying，Liu Fang-Yan，Wang Mei-Di
A solid-phase-radioimmunoassay (SPRIA) for the monitoring of blood digoxin level has been developed, in which a secondary antibody-coated polystyrene tubes are used. This noval method seems to be simple to use and only takes about an half hour. The standard curve is linear from 0.25 to 4 µg/L. The sensitivity of the detection is 0.1 µg/L. Reproducibility studies with 3 control sera of 0.5~2.5 µg/L give intraassay CV< 5% and interassay CV< 10%. The specimens are measured and compared with those of the conventional radioimmunoassay and the values are well correlated (r=0.96, Y=1.022X+0.04 µg/L).
keyword：SPRIA；Digoxin；Serium；
