弹道靶的一些发射技术

弹道靶设备是开展高速碰撞、气动力和气动物理现象研究的重要实验手段.由于比风洞和击波管等设备有它特殊的优点,所以五十年代末六十年代初,当它在高超音速领域中初

弹道靶上的跨音速实验

本文介绍用弹道靶作跨音速试验的新方法,在二级轻气炮上采用了二个特殊的新技术:充气放炮能发射模型达到亚音速,低充填条件能发射模型达到跨、超音速。由于初始加速度较小,发射的模型外形完整,姿态稳定;加上没有支撑干扰和小洞壁效应的优点,使弹道靶设备在跨音速实验方面有特殊的优越性,用上述技术得到了圆球跨音速流场的清晰照片,其中击波脱体距离、分离点位置、颈部宽度、尾迹形状与超音速、高超音速流动比较有明显变化。文中M≈1.010和M≈0.99的二张全流场照片是十分有意义的。最后提出一个想法,用靶场加压、降温的方法可以提高雷诺数直到10~7以上

Transition from tunneling leakage current to molecular tunneling in single-molecule junctions

数十年来，半导体工业一直遵循基于“摩尔定律”所设定的发展蓝图，逐步提升集成电路芯片上晶体管的集成度和运行速度，减小器件尺寸。为探索这一尺寸极限，课题组基于机械可控裂结技术自主开发了具有飞安级电学测量和亚纳米级位移控制灵敏度的科学仪器，在国际上首次获取了一系列具有不同重复单元的寡聚苯乙炔类分子电导随电极间距的演变关系，并发现随着电极间距的缩小，器件电输运由通过分子器件电流占主导逐步转变到由隧穿漏电流占主导。对于本研究中具有最小尺寸的寡聚苯乙炔分子器件，其由于隧穿漏电流所制约的尺寸极限可小至0.66 nm，预示了有机分子器件在未来电子器件小型化方面具有重要的应用潜力。 这一研究工作是在化学化工学院洪文晶教授、萨本栋微纳研究院杨扬助理教授以及英国Durham University的MartinR. Bryce教授共同指导下完成的。能源材料化学协同创新中心iChEM Fellow刘俊扬博士为论文第一作者，博士研究生郑珏婷、李瑞豪和硕士研究生黄晓艳、唐永翔、皮九婵、本科生王飞等参与了研究工作。田中群教授、毛秉伟教授和师佳副教授为论文工作提供了重要指导。【Abstract】The tunneling leakage current will be a major quantum obstacle during miniaturization in the semiconductor industry down to the scale of several nanometers. At this scale, to promote charge transport and overcome the tunneling leakage current between the source and drain terminals, molecular electronic junctions offer opportunities by inserting molecules between these two electrodes. Employing a series of oligo(aryleneethynylene) (OAE) molecules, here we investigate the transition from tunneling leakage current to molecular tunneling in the single-molecule devices using mechanically controllable break junction (MCBJ) technique, and the transition distances of the OAE molecular junctions were determined and even down to 0.66 nm for OAE2 molecular junction, which demonstrates that the intrinsic charge transport properties of a single-molecule device can be outstripped from the tunneling leakage current. Consequently, molecular electronic devices show the potential to push the ultimate limit of miniaturization to the scale of several angstroms.This work was supported by the National Key R&D Program of China (2017YFA0204902). This work was also generously supported by the Young Thousand Talent Project of China, the EC FP7 ITN “MOLESCO” project number 606728, the National Natural Science Foundation of China (nos. 21703188, 21673195, 21503179), and the China Postdoctoral Science Foundation (2017M622060). 该工作获得科技部国家重点研发计划课题（2017YFA0204902），国家自然科学基金委（21673195、21703188、21503179）以及中国博士后科学基金（2017M622060）等项目的资助，也得到了固体表面物理化学国家重点实验室、能源材料化学协同创新中心的支持

再入体激波层和近尾流热辐射实验研究

本文介绍了在弹道靶设备上对再入速度下模型的热辐射进行的实验研究工作。铝、高硅氧和聚碳酸酯三种材料的模型在速度为4.5～6.0(km/s),压力为600—8000Pa条件下做了实验,在258nm—1100nm光谱范围内完成了九个波段的辐射测量,给出了三种材料模型的辐射光谱分布曲线。结果表明辐射量除了受环境条件影响外,还强烈地依赖于模型材料;由烧蚀产物引起的辐射通量主要在可见光和近红外区(465nm以上)。估算了烧蚀产物引起的辐射加热率,对头部和近尾流辐射通量做了比较

Direct mass measurements of neutron-rich ~(86)Kr projectile fragments and the persistence of neutron magic number N=32 in Sc isotopes

<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">In this paper, we present direct mass measurements of neutron-rich Kr-86 projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of 52-54SC nuclides are determined to be -40492(82), -38928(114), -34654(540) keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 (AME12). In particular, Sc-53 and Sc-64 are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N=32 in Sc isotopes.</span

Shell Evolution Study for New Magic Number N =32 via Isochronous Mass Spectrometry

<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">Recent results and progress of mass measurements of neutron-rich nuclei utilizing Isochronous Mass Spectrometry (IMS) based on the HIRFL-CSR complex at Lanzhou are reported. The nuclei of interest were produced through projectile fragmentation of primary 86Kr ions at a realistic energy of 460.65 MeV/u. After in-flight separation by the fragment separator RIBLL2, the fragments were injected and stored in the experimental storage ring CSRe, and their masses were determined from measurements of their revolution times. The re-determined masses were compared and evaluated with other mass measurements, and the impact of these evaluated masses on the shell evolution study is discussed.</span