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Field emission from the structure of well-aligned TiO2/Ti nanotube arrays
No full textWell-aligned TiO2/Ti nanotube arrays were synthesized by anodic oxidation of titanium foil in 0.5 wt.% HF in various anoclization voltages. The images of filed emission scanning electron microscopy indicate that the nanotubes structure parameters, such as diameter, wall thickness and density, can be controlled by adjusting the anoclization voltage. The peaks at 25.3 degrees and 48.0 degrees of X-ray diffraction pattern illuminate that the TiO2 nanotube arrays annealed at 500 degrees C are mainly in anatase phase. The filed emission (FE) properties of the samples were investigated. A turn-on electric field 7.8 V/mu m, a field enhancement factors approximately 870 and a highest FE current density 3.4 mA/cm(2) were obtained. The emission current (2.3 mA/cm(2) at 18.8 V/mu m) was quite stable within 480 min. The results show that the FE properties of TiO2/Ti have much relation to the structure parameters.National Natural Science Foundation of China 10774121
Natural Science Foundation of Gansu Province of China 0803RJZA102
Foundation of Northwest Normal University NWNU-KJCXGC-03-22
Foundation of Education Bureau of Gansu Province of China 0801-0
Observation of Three-Quasiparticle Doublet Bands in I-123: Possible Evidence of Chirality
No full textA new band in the odd proton nucleus I-123 is identified via in- beam gamma- ray spectroscopy using the N-14+Cd-116 reaction. This band shows up as doublets with the previously assigned pi g(7/2) circle times (nu h(11/2))(2) band. Possible configurations of the new band are discussed in the framework of the cranked shell model and the geometrical model. It is argued that the new band might be a chiral partner of the previously known pi g(7/2) circle times (nu h(11/2))(2) band
Shell-model Hamiltonian from self-consistent mean-field model: N = Z nuclei
No full textWe propose a procedure to determine the effective nuclear shell-model Hamiltonian in a truncated space from a self-consistent mean-field model, e.g., the Skyrme model. The parameters of pairing plus quadrupole-quadrupole interaction with monopole force are obtained so that the potential energy surface of the Skyrme Hartree-Fock + BCS calculation is reproduced. We test our method for N = Z nuclei in the fpg- and sd-shell regions. It is shown that the calculated energy spectra with these parameters are in a good agreement with experimental data, in which the importance of the monopole interaction is discussed. This method may represent a practical way of defining the Hamiltonian for general shell-model calculations. (C) 2009 Elsevier B.V. All rights reserved.National Natural Science Foundation of China 10875077
Chinese Major State Basic Research 2007CB81500
Hyperfine quenching of the 3s3p P-3(0) level in Mg-like ions
No full textHyperfine quenching rates of the 3s3p P-3(0) level in Mg-like ions were calculated using the GRASP2K package based on the multi-configuration Dirac-Hartree-Fock method. Valence and core-valence correlation effects were accounted for in a systematic way. Breit interactions and QED effects were included in the subsequent relativistic CI calculations. Calculated rates were compared with other theoretical values and with experiment, and a good agreement with the latest experimental value for the Al-27(+) ion (Rosenband et al 2007 Phys. Rev. Lett. 98 220801) was found. Furthermore, we showed in detail the contributions from Breit interaction and QED effects to concerned physical properties. Finally, electronic data were presented in terms of a general scaling law in Z that, given isotopic nuclear spin and magnetic moment, allows hyperfine-induced decay rates to be estimated for any isotope along the isoelectronic sequence.National Nature Science Foundation of China 10774122
10876028
specialized Research Fund for the Doctoral Program of Higher Education of China 20070736001
Foundation of Northwest Normal University NWNU-KJCXGC-03-21
Swedish Research Counci
~(12)C~(6+)重离子束照射治疗复发性软组织肉瘤临床疗效探讨
No full text目的: 应用我国自主研发的重离子加速器产生的12C6+重离子束治疗复发性软组织肉瘤,评价其高线性能量传递 (LET)及低 LET在临床应用中的优劣. 方法: 3例经病理证实为软组织肉瘤自愿接受重离子束照射的患者,其中 2例病变位于腹部,1例在背部. 所有患者均为手术复发 2次以上,最多达 6次,并经手术行常规放疗失败. 应用 80～100mev/u重离子束对 3例患者分别给予总剂量 72～120 GyE/6212 f照射,生物效应剂量 (RBE) =3. 结果:2例患者 3mo后病变完全消失,达临床治愈;1例缩小 75%,达临床部分缓解,总有效率为100%.治疗中及治疗后照射野皮肤无破溃等放射性损伤.结论:12C6+重离子束具有治疗精度高,疗程短,对肿瘤周围正常组织损伤小等特点. 特别在射线抗拒的难治性肿瘤中可达到常规放疗难以实现的疗效,具有很好的临床应用前景.国家“863”课题 (2006AAo2z499);国家自然科学基金(10675151
Magnetic characterization of Co1-xNixFe2O4 (0 <= x <= 1) nanoparticles prepared by co-precipitation route
No full textMagnetic nanoparticles of Ni-doped cobalt ferrite [Co1-xNixFe2O4(0 <= x <= 1)] synthesized by coprecipitation route have been studied as a function of doping concentration (x) and particle size. The size of the particles as determined by X-ray diffractometer (XRD) and transmission electron microscope (TEM) analyses was found in the range 12-48 nm. The coercivity (H-C) and saturation magnetization (M-S) showed a decreasing behavior with increasing Ni concentration. M-S of all the samples annealed at 600 degrees C lies in the range 65.8-13.7 emu/gm. Field-cooled (FC) studies of the samples showed horizontal shift (exchange bias) and vertical shift in the magnetization loop. Strong decrease in exchange bias (H-b) and vertical shift (delta M) was found for low Ni concentrations while negligible decrease was found at higher concentrations. The presence of exchange bias in the low Ni-concentration region has been explained with reference to the interface spins interaction between a surface region (with structural and spin disorder) and a ferrimagnetic core region. M(T) graphs of the samples showed a decreasing trend of blocking temperature (T-b) with increasing Ni concentration. The decrease of T-b with increasing Ni concentration has been attributed to the lower anisotropy energy of Ni+2 ions as compared to Co+2 that increases the probability of the jump across the anisotropy barrier which in turn decreases the blocking temperature of the system.Material Science Group-II, Institute of Modern Physics
Chinese Academy of Sciences, Lanzhou, PR Chin
Shell effect and capture cross sections in the synthesis of superheavy nuclei
No full textThe shell effect is included in the improved isospin dependent quantum molecular dynamics model in which the shell correction energy of the system is calculated by using the deformed two-center shell model. A switch function is introduced to connect the shell correction energy of the projectile and the target with that of the compound nucleus during the dynamical fusion process. It is found that the calculated capture cross sections reproduce the experimental data quantitatively at the energy near the Coulomb barrier. The capture cross sections for reaction (35) (80) Br + (82) (208) Pb -> (117) (288) X are also calculated and discussed.National Natural Science Foundation of China 10575012
10435020
Doctoral Station Foundation of Ministry of Education of China 20080027001
Effects of Naotan Pill on repair of neural cells and cognitive disorders in juvenile rats following hypoxia and ischemia
No full textBACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccharide, the most effective component of barbary wolfberry fruit, has protective effects on neural cells in hypoxia-ischemia.
OBJECTIVE: To investigate the effects of Naotan Pill on glutamate-treated neural cells and on cognitive function in juvenile rats following hypoxia-ischemia.
DESIGN, TIME AND SETTING: The randomized, controlled, in vivo study was performed at the Cell Laboratory of Lanzhou University, Lanzhou Institute of Modern Physics of Chinese Academy of Sciences, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from December 2005 to August 2006. The cellular neurobiology, in vitro experiment was conducted at the Institute of Human Anatomy, Histology, Embryology and Neuroscience, School of Basic Medical Sciences, Lanzhou University, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from March 2007 to January 2008.
MATERIALS: Naotan Pill, composed of barbary wolfberry fruit, danshen root, grassleaf sweetflag rhizome, and glossy privet fruit, was prepared by Gansu Provincial Rehabilitation Center, China. Rabbit anti-synaptophysin, choline acetyl transferase polyclonal antibody, streptavidin-biotin complex kit and diaminobenzidine kit (Boster, Wuhan, China), as well as glutamate (Hualian, Shanghai, China) were used in this study.
METHODS: Cortical neural cells were isolated from neonatal Wistar rats. Neural cell damage models were induced using glutamate, and administered Naotan Pill prior to and following damage. A total of 54 juvenile Wistar rats were equally and randomly assigned into model, Naotan Pill, and sham operation groups. The left common carotid artery was ligated, and then rat models of hypoxic-ischemic injury were assigned to the model and Naotan Pill groups. At 2 days following model induction, rats in the Naotan Pill group were administered Naotan Pill suspension for 21 days. In the model and sham operation groups, rats received an equal volume of saline.
MAIN OUTCOME MEASURES: Neural cell morphology was observed using an inverted phase contrast microscope. Survival rate of neural cells was measured by MTT assay. Synaptophysin and choline acetyl transferase expression was observed in the hippocampal CA1 region of juvenile rats using immunohistochemistry. Cognitive function was tested by the Morris water maze.
RESULTS: Pathological changes were detected in glutamate-treated neural cells. Neural cell morphology remained normal after Naotan Pill intervention. Absorbance and survival rate of neural cells were significantly greater following Naotan Pill intervention, compared to glutamate-treated neural cells (P < 0.05). Synaptophysin and choline acetyl transferase expression was lowest in the hippocampal CA1 region in the model group and highest in the sham operation group. Significant differences among groups were observed (P < 0.05). Escape latency and swimming distance were significantly longer in the model group compared to the Naotan Pill group (P < 0.05).
CONCLUSION: Naotan Pill exhibited protective and repair effects on glutamate-treated neural cells. Naotan Pill upregulated synaptophysin and choline acetyl transferase expression in the hippocampus and improved cognitive function in rats following hypoxia-ischemia
Characteristics of a 4-fold segmented clover detectore
No full textFour high-purity germanium 4-fold segmented Clover detectors have been applied in the experiment of neutron-rich nucleus N-21. The performance of those, four Clovers have been tested with radioactive sources and in-beam experiments and the main results including energy resolution, peak-to-total ratios, the variation of the hit pattern distribution in difficult crystals of one Clover detector with the energy of gamma ray, and absolute full energy peak detection efficiency curve, were presented.National Basic Research Program (973 program) of China 2007CB81500
2005CB724800
National Natural Science Foundation or China 10775003
10475004
10405001
10221003
J073031
Direct Measuring the Internal Energy to Study the Fragmentation Mechanism of Small Biomolecule Induced by Ions
No full text从分子层面认识活体细胞受辐射损伤过程时，生物小分子碎裂反应可能扮演着重
要的作用，因此其碎裂动力学倍受关注。能量沉积是研究此类反应的一个重要但测量
困难的物理量，CIDEC 方法的出现使实验直接测量变为可能。本文将该方法成功用于生
物分子 Ade 和 FeTPPCl，为其碎裂动力学研究提供了新视角。
在 3keV Cl+-Ade 碰撞中，从所测激发能分布证实了 Ade2+
主要解离道为级联发射HCN或H2CN+。实验还发现一新解离道，即发射离子 H2CN+
后再发射中性 HC2N2，产生碎片C2H2N2+的碎裂通道，所需平均激发能为 8.4eV。
对靶分子 FeTPPCl，80keV Kr8+入射时，实验获得了 FeTPPCl1+,2+,3+碎裂产生的质
谱，发现在相同能量窗下它们解离第一步均是耗能低的 Cl0出射，接下来二价母体离子
以蒸发中性碎片为主，三价母体离子以非对称碎裂发射荷电苯基为主。在 3keV H+及F+
入射时，观测到了不同反应能量窗下 TOF 谱分布的变化，测出了两种入射离子下二价
母体离子激发能分布随各解离通道的变化关系，并作了对比分析。实验还发现蒸发 nH2
过程。
本文还提供了一种直接测量碰撞中负离子相对产额的新方法，并用于 30keV F2+-Ade 反应，
测得负离子 F-相对产额约为 1%