Institutional Repository of Institute of Modern Physics, CAS
Not a member yet
5769 research outputs found
Sort by
Measurement of K*(892)(0) and K-0 mesons in Al plus Al collisions at 1.9A GeV
A new measurement of subthreshold K*(892)(0) and K-0 production is presented. The experimental data complete the measurement of strange particles produced in Al + Al collisions at 1.9A GeV measured with the FOPI detector at SIS at GSI (Darmstadt). The K*(892)(0)/K-0 yield ratio is found to be 0.0315 +/- 0.006(stat.) +/- 0.012(syst.) and is in good agreement with the transport model prediction. These measurements provide information on the in-medium cross section of K+-pi(-) fusion, which is the dominant process in subthreshold K*(892)(0) production
Experimental study of the beta-delayed proton decays of Er-145,Er-147
The beta-delayed proton decays of Er-145,Er-147 have been studied experimentally using the Ni-58 + Mo-92 reaction at beam energy of 383 MeV. On the basis of a He-jet apparatus coupled with a tape transport system, the beta-delayed proton radioactivities both from the nu s(1/2) ground state and the nu h(11/2) isomer in Er-145,Er-147 were observed by proton-gamma coincidence measurements. By analyzing the time distributions of the 4(+) -> 2(gamma)(+) transitions in the granddaughter nuclei Dy-144,Dy-146, the half-lives of 1.0 +/- 0.3 s and 1.6 +/- 0.2 s have been deduced for the nu h(11/2) isomers in Er-145,Er-147, respectively
碳离子辐照诱导人外周血淋巴细胞染色体畸变的时间和剂量效应
目的:研究碳离子辐照诱导淋巴细胞染色体畸变的时间和剂量效应。方法:以加速的碳离子为辐射源,吸收剂量分别为2、4Gy的碳离子辐照人外周血淋巴细胞后,分别培养48、72、84h后收集细胞,用姊妹染色单体区别染色法分析淋巴细胞第一次分裂中期染色体畸变,以研究畸变的时间效应;吸收剂量为0、0.5、1、2、3、4Gy的碳离子辐照人外周血淋巴细胞后,培养48h,用常规染色体技术研究碳离子辐照诱导淋巴细胞染色体畸变的剂量效应。结果:辐照后分别培养48、72和84h得到的双着丝粒和着丝粒环畸变("双+环"畸变)频率没有明显差异;在0.5~4Gy剂量范围内,"双+环"畸变的量效关系符合线性关系:Y=0.0005+0.689D。结论:在本实验辐照条件下,碳离子辐射诱导淋巴细胞染色体畸变不存在时间效应,可以用48h的培养时间来研究碳离子的生物学效应,并发现染色体"双+环"畸变随剂量的增加而呈线性增加
浅谈科学事业单位实行国库集中支付后如何做好出纳工作
<正>随着我国经济体制改革的不断深入,财会制度改革也不断深化,特别是《中共中央关于制定国民经济和社会发展第十一个五年规划的建议》,明确提出要推进财政税收体制改革,加快公共财政体系建设,继续深化部门预算,国库集中支付,政府采购和收支两条线管理制度改革,随之,我国科研事业单位财会制度改革又有了新的进展。近年来由于国家对科研工作的高度重视,国家对科研项目的投资规模很大。为了保证科研
基于GEANT4的CsI(Tl)闪烁体探测器的Monte Carlo模拟;Monte Carlo Simulation of CsI(Tl) Scintillator Detector with GEANT4 ToolKit
对闪烁光在晶体内的传输以及光电子倍增过程进行了建模,基于GEANT4软件包对CsI(T1)闪烁体探测器进行了蒙特卡罗模拟,得到了不同形状、尺寸和包装的CsI(Tl)晶体测量γ射线的能谱。对比模拟和测试结果,两者得到了很好的符合,从而验证了模拟参数的合理性和可靠性。该模拟程序的建立为闪烁体探测器的设计提供了更精确的开发工具
Nonapeptide突变体制备及抗新城疫病毒活性研究;Preparation of Nonapeptide Mutant and Antiviral Effect on Newcastle Disease Virus
以生物工程技术表达及120 g/L SDS-PAGE电泳纯化Nonapeptide突变体,取制备的Non-apeptide突变体进行抗新城疫病毒(NDV)的鸡胚试验、鸡体内抗NDV试验。结果表明,当Nonapeptide突变体基因产物浓度达4μg/mL~6μg/mL,对鸡胚保护率均达到100%,感染鸡胚全部存活;Nonapeptide突变体基因产物浓度大于4μg/mL,对NDV有很好的抑制作用,鸡用药后3 d体内检测不到NDV,低剂量组(2μg/mL)也有较好的抑制NDV作用,鸡用药后5 d体内检测不到NDV。Nonapeptide突变体基因产物具有NDV多克隆抗体相似活性,能够抑制鸡胚中和组织培养中NDV的繁殖,具有中和、抑制NDV吸附作用
Development of multi-channel gated integrator and PXI-DAQ system for nuclear detector arrays
A multi-channel gated integrator and PXI based data acquisition system have been developed for nuclear detector arrays with hundreds of detector units. The multi-channel gated integrator can be controlled by a programmable Cl controller. The PXI-DAQ system consists of NI PXI-1033 chassis with several PXI-DAQ cards. The system software has a user-friendly GUI which is written in C language using LabWindows/CVI under Windows XP operating system. The performance of the PXI-DAQ system is very reliable and capable of handling event rate up to 40 kHz. (C) 2010 Elsevier B.V. All rights reserved
Preliminary study of a niobium quarter-wave prototype cavity for a heavy-ion superconducting linac
Superconducting quarter-wave resonators, due to their compactness and their convenient shape for tuning and coupling, are very attractive for low-beta beam acceleration. In this paper, two types of cavities with different geometry have been numerically simulated: the first type with larger capacitive load in the beam line and the second type of lollipop-shape for 100 MHz, beta=0.06 beams; then the relative electromagnetic parameters and geometric sizes have been compared. It is found that the second type, whose structural design is optimized with the conical stem and shaping drift-tube, can support the better accelerating performance. At the end of the paper, some structural deformation effects on frequency shifts and appropriate solutions have been discussed
Measurement of the total reaction cross section for the mirror nuclei N-12 and B-12
The mirror nuclei N-12 and B-12 are separated by the Radioactive Ion Beam Line in Lanzhou (RIBLL) at HIRFL from the breakup of 78.6 MeV/u N-14 on a Be target. The total reaction cross-sections of N-12 at 34.9 MeV/u and B-12 at 54.4 MeV/u on a Si target have been measured by using the transmission method. Assuming N-12 consists of a C-11 core plus one halo proton, the excitation function of N-12 and B-12 on a Si target and a C target were calculated with the Glauber model. It can fit the experimental data very well. The characteristic halo structure for N-12 was found with a large diffusion of the protons density distribution