Study of neutron activation yields in spallation reaction of 400 MeV/u carbon on a thick lead target

The spallation-neutron yield was studied experimentally by bombarding a thick lead target with 400 MeV/u carbon beam. The data were obtained with the activation analysis method using foils of Au, Mn, Al, Fe and In. The yields of produced isotopes were deduced by analyzing the measured γ spectra of the irradiated foils. According to the isotopes yields, the spatial and energy distributions of the neutron field were discussed. The experimental results were compared with Monte Carlo simulations performed by the GEANT4+FLUKA code.     

斯伦贝谢微球测井仪技术改造

本文讨论了对斯伦贝谢微球测井仪进行技术改造的几种方法，并给出了最佳方案。     

Configuration of the valence neutrons of 17B

The reaction cross section of ¹⁷B on ¹²C target at (43.7±2.4)MeV/u has been measured at the Radioactive Ion Beam Line in Lanzhou (RIBLL). The root-mean-square matter radius (R_rms) was deduced to be (2.92±0.10)fm, while the R_rms of the core and the valence neutron distribution are 2.28fm and 5.98fm respectively. Assuming a ``core plus 2n' structure in ¹⁷B, the mixed configuration of (2s_1/2) and (1d_5/2) of the valence neutrons is studied and the     

融合感性工学与人体工程学设计汽车椅的研究

通过人体工程学理论分析驾乘人员人体参数,规范符合人体坐姿的安全座椅尺寸。以感性工学为理论指导,满足驾乘人员生理和心理需求。运用KJ法完成分类评估,收集汽车座椅相关图片数据集,选取适合的感性词汇,运用层次分析法对汽车座椅进行感性评价,分析感性词汇与汽车座椅设计的关联性,结合人体工程学理论,对创新设计汽车座椅形态进行理性的指导,实现了驾乘人员“情感和体验”的舒适型汽车座椅设计。     

基于虚拟仪器的机械振动测试系统设计

作为虚拟仪器技术的核心软件,LabVIEW以其图形化编程界面和便利的开发环境在测控领域中得到广泛应用.为实现对机械设备状态监测与故障诊断,通过虚拟仪器技术分析、系统软硬件设计、上下位机联调等过程的开发与研究,形成一套机械振动测试系统,通过系统模拟实验和现场实验对比分析,验证该系统具备一定的可行性和适用性,可以为同类系统...     

基本数学活动经验研究述评

本文旨在通过文献检索和分析,针对我国基础教育阶段关于基本数学活动经验的研究背景、内涵、内容与分类、特征、水平层次的界定及其对数学课程教学的意义和实施要点进行讨论,并提出了亟待解决的研究问题,以期为基本数学活动经验在基础教育阶段数学课堂教学中的具体实施提供一定的依据。     

抗克伦特罗噬菌体单链抗体库的构建、筛选及鉴定

利用噬菌体展示技术构建克伦特罗(CBL)单链抗体(scFv)库,从中筛选CBL特异性噬菌体scFv,从而成功扩增出抗CBL的VL,VH基因片段并采用重叠延伸PCR拼接为全长的scFv基因片段,抗体库库容约为1.6×104,经4轮吸附—洗脱—扩增的富集,采用酶联免疫吸附测定(ELISA)法筛选到6个具有CBL结合活性的噬菌体scFv,为进一步大量表达CBL单链抗体奠定了基础.     

低功率毫米波辐射对HL60细胞基因表达谱的影响

摘要：研究低功率毫米波辐射对HL60白血病细胞基因表达谱的影响。应用基因芯片检测频率41.32GHz的毫米波辐射HL60白血病细胞和未辐射毫米波HL60白血病细胞组基因表达差异,并进行RT-PCR方法验证IL-7、EGF和LGALS3基因变化。 结果与对照组比较,毫米波辐射60min后,HL60细胞增殖,基因芯片检出基因表达上调18个和下调306个,在下调的基因中,RT-PCR 检出IL-7、EGF和LGALS3基因下调与基因芯片结果一致。表明低功率毫米波可导致HL60细胞基因表达谱发生变化,这些变化的基因与HL60细胞增殖功能相关。提示基因表达变化是低功率毫米波辐射HL60细胞所致生物学反应的重要因素。     

基于双核模型对准裂变产物质量分布的研究

在双核模型基础上引入一维的Kramers公式，计算了⁴⁸Ca+²⁴⁴Pu，⁴⁸Ca+²³⁸U和⁵⁸Fe+²³²Th这三个反应准裂变碎片的质量分布，得到了与实验比较符合的结果.同时提取出了碎片质量分布随时间的演化关系，为理解熔合与准裂变竞争过程提供了非常有用的信息.由于准裂变在重离子熔合反应中起着重要作用，理论计算与实验结果的比较是对现有熔合模型的重要检验. 关键词： 超重元素 熔合反应 准裂变产物 质量产额     

Angular Dispersion and Deflection Function for Heavy Ion Elastic Scattering

The differential cross sections for elastic scattering products of ^17F on ^208Pb have been measured. The angular dispersion plots of ln（dσ/dθ） versus θ^2 are obtained from the angular distribution of the elastic scattering differential cross sections. Systematical analysis on the angular dispersion for the available experimental data indicates that there is an angular dispersion turning angle at forward angular range within the grazing angle. This turning angle can be clarified as nucleal rainbow in classical deflection function. The exotic behaviour of the nuclear rainbow angle offers a new probe to investigate the halo and skin phenomena.