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Micronuclei induction in human lymphocytes induced by carbon ions exposion along the penetrate depth of ions in water
No full textHere we used cytokinesis-block micronucleus assay to measure the biological response along the penetrate
depth of ions in water in human lymphocytes exposed to 100 MeV/u incident carbon ions in vitro.
Polyethylene shielding was used to change the penetration depth of ions in water. A quantitative biological
response curve was generated for micronuclei induction. The results showed a marked increase with
the penetrate depth of ions in water in the micronuclei formation, which was consistent with a linearenergy-
transfer dependent increase in biological effectiveness. The dose–response relationship for MN
information was different at different penetrate depth of ions in water, at the 6 and 11.2 mm penetrate
depth of ions in water, the dose–response relationships for the micronucleus frequencies induced by carbon
ions irradiation were linear; while it was power function at 17.1 mm penetrate depth
THEORETICAL STUDY ON pp -> pn pi(+) REACTION AT MEDIUM ENERGIES
No full textThe pp -> pn pi(+) reaction is a channel with the largest total cross section for pp collision in COSY/CSR energy region. In this work, we investigate individual contributions from various N* and Delta* resonances with mass up to about 2 GeV for the pp -> pn pi(+) reaction. We extend a resonance model, which can reproduce the observed total cross section quite well, to give theoretical predictions of various differential cross sections for the present reaction at T-p = 2.88 GeV. It could serve as a reference for identifying new physics in the future experiments at HIRFL-CSR
Flower color chimera and abnormal leaf mutants induced by C-12(6+) heavy ions in Salvia splendens Ker-Gawl.
No full textThe effect of C-12(6+) heavy ions bombardment on mutagenesis in Salvia splendens Ker-Gawl. was studied. Dose-response studies indicated that there was a peak of malformation frequency of S. splendens at 200 Gy. Abnormal leaf mutants of the bileaf, trileaf and tetraleaf conglutination were selected. Meanwhile, a bicolor flower chimera with dark red and fresh red flower was isolated in M1 generation of S. splendens. Random amplified polymorphic DNA (RAPD) analysis demonstrated that DNA variations existed among the wild-type, fresh and dark red flower shoots of the chimera. The dark red flower shoots of the chimera were conserved and cultivated at a large-scale through micropropagation. MS supplemented with 2.0 mg/L BA and 0.3 mg/L NAA was the optimal medium in which the maximum proliferation ratio (5.2-fold) and rooting rate (88%) were achieved after 6 weeks. Our findings provide an important method to improve the ornamental quality of S. splendens.Program for New Century Excellent Talents in University (NCET)
Gansu Province Program for Research and Exploitation of Agriculture Biotechnology GNSW-2006-1
Proposal for studying N* resonances with the (p)over-barp -> (p)over-barn pi(+) reaction
No full textA theoretical study of the (p) over barp -> (p) over barn pi(+) reaction for antiproton beam energy from 1 to 4 GeV is made by including contributions from various known N* and Delta* resonances. It is found that for the beam energy around 1.5 GeV, the contribution of the Roper resonance N-(1440)* produced by the t-channel sigma exchange dominates over all other contributions. Since such a reaction can be studied in the forthcoming PANDA experiment at the GSI Facility of Antiproton and Ion Research (FAIR), the reaction will be realistically the cleanest place for studying the properties of the Roper resonance and the best place for looking for other "missing" N* resonances with large coupling to N sigma
Projected shell model description for high-spin states in neutron-rich Fe isotopes
No full textA systematic study of neutron-rich even-even Fe isotopes with a neutron number from 32 to 42 is carried out by using the projected shell model. Calculations are performed up to the spin I=20 state. Irregularities found in the yrast spectra and in B (E2) values are discussed in terms of neutron excitations to the high-j orbital g(9/2). Furthermore, the neutron two-quasiparticle structure of a low-K negative-parity band and the proton two-quasiparticle structure of a high-K positive-parity band are predicted to exist near the yrast region. Our study reveals a soft nature for the ground state of N approximate to 40 isotopes and emphasizes the important role of the neutron g(9/2) orbital in determining the structure properties for both low- and high-spin states in these nuclei.National Natural Science Foundation of China 10875077
Chinese Major State Basic Research Development Program 2007CB815005
SJTU-INS Research Project for Visiting Scholar
ATOMIC PHYSICS RESEARCHES AT COOLER STORAGE RING IN LANZHOU
No full textThe commissioning of the cooler storage rings (CSR) was successful, and the facility provides new possibilities for atomic physics with highly charged ions. Bare carbon, argon ions, were successfully stored in the main ring CSRm, cooled by cold electron beam, and accelerated up to 1 GeV/u. Heavier ions as Xe44+ and Kr28+ were also successfully stored in the CSRs. Both of the rings are equipped with new generation of electron coolers which can provide different electron beam density distributions. Electron-ion interactions, high precision X-ray spectroscopy, complete kinematical measurements for relativistic ion-atom collisions will be performed at CSRs. Laser cooling of heavy ions are planned as well. The physics programs and the present status will be summarized
OVERVIEW ON THE HIRFL-CSR FACILITY
No full textThe status of the HIRFL (Heavy Ion Facility in Lanzhou) - Cooler Storage Ring (CSR) at the IMP is reported. The main physics goals at the HIRFL-CSR are the researches on nuclear structure and decay property, EOS of nuclear matter, hadron physics, highly charged atomic physics, high energy density physics, nuclear astrophysics, and applications for cancer therapy, space industries, materials and biology sciences. The HIRFL-CSR is the first ion cooler-storage-ring system in China, which consists of a main ring (CSRm), an experimental ring (CSRe) and a radioactive beamline (RIBLL2). The two existing cyclotrons SFC (K=70) and SSC (K=450) are used as its injectors. The 7MeV/u12C6+ ions were stored successfully in CSRm with the stripping injection in January 2006. After that, realized were the accelerations of C-12(6+), Ar-36(18+), Kr-78(28+) and Xe-129(27+) ions with energies of 1GeV/u, 1GeV/u, 450 MeV/u and 235 MeV/u, respectively, including accumulation, electron cooling and acceleration. In 2008, the first two isochronous mass measurement experiments with the primary beams of Ar-36(18+) and Kr-78(28+) were performed at CSRe with the Delta p/p similar to 10(-5)
Charge-sensitive deep level transient spectroscopy of helium-ion-irradiated silicon, as-irradiated and after thermal annealing
No full textElectrically active defects in the phosphor-doped single-crystal silicon, induced by helium-ion irradiation under
thermal annealing, have been investigated. Isothermal charge-sensitive deep-level transient spectroscopy was employed
to study the activation energy and capture cross-section of helium-induced defects in silicon samples. It was shown that
the activation energy levels produced by helium-ion irradiation first increased with increasing annealing temperature,
with the maximum value of the activation energy occurring at 873K, and reduced with further increase of the annealing
temperature. The energy levels of defects in the samples annealed at 873 and 1073K are found to be located near the
mid-forbidden energy gap level so that they can act as thermally stable carrier recombination centres
Formation of Au nanoparticles in sapphire by using Ar ion implantation and thermal annealing
No full textIn this paper, we present results of the synthesis of gold nanoclusters in sapphire, using Ar ion implantation and annealing in air. Unlike the conventional method of Au implantation followed by thermal annealing, Au was deposited on the surface of m- and a- cut sapphire single crystal samples including those pre-implanted with Ar ions. Au atoms were brought into the substrate by subsequent implantation of Ar ions to form Au nanoparticles. Samples were finally annealed stepwisely in air at temperatures ranging from 400 to 800 C and then studied using UV–vis absorption spectrometry, transmission electron microscopy and Rutherford backscattered spectrometry. Evidence of the formation Au nanoparticles..
Analysis of Effects in a Low-activation Ferritic/Martensitic Steel by High-energy Heavy-ion Irradiation
No full textLow-activation Ferritic/Martensitic steels are a kind of important structural materials candidate to the application in advanced nuclear energy systems.Possible degradation of properties and even failure in the condition of high-temperature and high helium production due to energetic neutron irradiation in a fusion reactor is a major concern with the application of this kind of materials.In the present work microstructural evolution in a 9Cr Ferritic/Martensitic steel(T92B) irradiated with 122 MeV 20Ne ions...中文摘要：低活化的铁素体/马氏体钢是先进核能装置(如聚变堆)的重要候选结构材料。在聚变堆实际工作环境下,由于高温和高氦产生率引起的材料失效是这类材料面临的一个重要问题。本项研究以兰州重离子加速器(HIRFL)提供的中能惰性气体离子束(20Ne,122 MeV)作为模拟辐照条件,借助透射电子显微镜,研究了一种低活化的9Cr铁素体/马氏体钢(T92B)组织结构的变化和辐照肿胀。实验结果表明,高温下当材料中晶格原子的撞出损伤和惰性气体原子沉积浓度超过一定限值时,材料内部形成高浓度的空洞,并且空洞肿胀率显著依赖于辐照温度和剂量;在马氏体板条界面及其它晶界处空洞趋于优先形成,并且在晶界交汇处呈加速生长。基于氦泡的形核生长与空洞肿胀的经典模型探讨了在不同辐照条件(He离子、Ne离子、Fe/He离子双束、快中子、Ni离子)下铁素体/马氏体钢中肿胀率数据的关联