Correction to: Theoretical prediction of radiation-enhanced diffusion behavior in nickel under self-ion irradiation

Nuclear Science and Techniques - 166.6-MHz quarter-wave $$\beta =1$$ superconducting cavities have been adopted for the High Energy Photon Source, a 6-GeV diffraction-limited synchrotron light...     

基于Creator/Vega的虚拟校园漫游系统的研究与实现

以山东建筑大学为背景,采用Creator软件平台开发了虚拟校园漫游系统.文中介绍了虚拟校园建模流程,通过纹理制作及映射技术降低了复杂模型的制作难度、增加了模型的真实感,利用三维模型优化技术提升了系统的响应速度、实现了实时性与真实性的平衡.最后使用vega驱动平台,成功实现了对校园虚拟场景的运行和仿真.     

Elastic Properties and Stacking Fault Energies of Borides,Carbides and Nitrides from First-Principles Calculations

Owing to the excellent elastic properties and chemical stability, binary metal or light element borides, carbides and nitrides have been extensively applied as hard and low-compressible materials. Researchers are searching for harder materials all the time. Recently, the successful fabrication of nano-twinned cubic BN(Tian et al. Nature 493:385–388, 2013) and diamond(Huang et al. Nature 510:250–253, 2014) exhibiting superior properties than their twin-free counterparts allows an efficient way to be harder. From this point of view, the borides, carbides and nitrides may be stronger by introducing twins, whose formation tendency can be measured using stacking fault energies(SFEs). The lower the SFEs, the easier the formation of twins. In the present study, by means of first-principles calculations, we first calculated the fundamental elastic constants of forty-two borides, seventeen carbides and thirty-one nitrides, and their moduli, elastic anisotropy factors and bonding characters were accordingly derived. Then, the SFEs of the {111} 112 glide system of twenty-seven compounds with the space group F43 m or Fm3m were calculated. Based on the obtained elastic properties and SFEs, we find that(1) light element compounds usually exhibit superior elastic properties over the metal borides, carbides or nitrides;(2) the 5 d transitionmetal compounds(ReB_2, WB, OsC, RuC, WC, OsN_2, TaN and WN) possess comparable bulk modulus( B) with that of cBN( B = 363 GPa);(3) twins may form in ZrB, HfN, PtN, VN and ZrN, since their SFEs are lower or slightly higher than that of diamond(SFE = 277 mJ/m~2). Our work can be used as a valuable database to compare these compounds.     

数控改造车床滚压加工C型压力管

数控改造普通车床,滚压加工压力仪表上材料为H62的C型压力弹簧管,扩展了数控技术的应用范围.将一般数控机床单一的单位控制精度改造为多单位控制精度,并针对实际加工中需要的不同滚压次数,可以实现C型压力弹簧管的异速滚压和整型定型的有效控制.     

Mechanical properties of Si nanowires as revealed by in situ transmission electron microscopy and molecular dynamics simulations

Deformation and fracture mechanisms of ultrathin Si nanowires (NWs), with diameters of down to ~9 nm, under uniaxial tension and bending were investigated by using in situ transmission electron microscopy and molecular dynamics simulations. It was revealed that the mechanical behavior of Si NWs had been closely related to the wire diameter, loading conditions, and stress states. Under tension, Si NWs deformed elastically until abrupt brittle fracture. The tensile strength showed a clear size dependence, and the greatest strength was up to 11.3 GPa. In contrast, under bending, the Si NWs demonstrated considerable plasticity. Under a bending strain of <14%, they could repeatedly be bent without cracking along with a crystalline-to-amorphous phase transition. Under a larger strain of >20%, the cracks nucleated on the tensed side and propagated from the wire surface, whereas on the compressed side a plastic deformation took place because of dislocation activities and an amorphous transition.     

Complex Precipitation Sequences of Al-Cu-Li-(Mg)Alloys Characterized in Relation to Thermal Ageing Processes

The Al-Cu-Li-(Mg) alloy is a high-performance lightweight material strengthened by complex coexisting precipitates that form in the alloy upon thermal ageing.Using high-resolution(scanning) transmission electron microscopy in association with first-principles energy calculations,we systematically studied the complex coexisting precipitates in the alloys and correlated their precipitation sequences with thermal ageing processes applied.The principal results are the following:(1) eight types of precipitates can be observed in the alloy;(2) of these precipitates,the T_1-phase is most stable.The S-phase precipitates with segregated Li atoms at their interfacial edges are unexpectedly more stable than the σ-phase;(3) the T1-phase has a characteristic precursor that plays the key role in its nucleation and growth.     

Rashba效应下量子点中束缚极化子的有效质量

采用线性组合算符、LLP幺正变换和变分方法,研究Rashba效应下量子点中强耦合束缚极化子有效质量的性质。对RbCl量子点数值计算的结果表明：极化子的振动频率、有效质量均随极化子速率、受限强度和库仑束缚势的增大而增大,原因是极化子速率增大电子动能增加,库仑束缚势增大导致电子-声子间相互作用增强,受限强度增大使电子运动的有效范围减小导致电子能量增大,进而使极化子的振动频率和有效质量增大。受Rashba自旋轨道相互作用的影响,极化子的有效质量发生劈裂,劈裂间距随极化子速率的增大而减小。     

敞开式离子化质谱新技术及其应用

敞开式离子化质谱(ambient mass spectrometry,AMS)是近年来新兴的一种无需或者只需很少样品前处理步骤,在敞开的大气压环境中可直接对物体表面物质进行离子化的质谱分析技术。本实验室基于敞开式离子源实时直接分析(direct analysis in real time,DART),进行了多方面的研究。主要包括三个方面:第一,应用研究,将简单的样品前处理技术和DART-MS结合,建立了有针对性的快速检测方法;第二,实现正相液相色谱(normal phase liquid chromatography,NPLC)和DART-MS的在线联用,解决了NPLC-MS联用中正相色谱流动相不利于样品离子化的问题,并利用该方法对NPLC分离的手性化合物进行了有效检测;第三,构建了一套新的AMS装置—等离子体辅助多波长激光解吸离子化质谱(plasma assisted multiwavelength laser desorption ioniza-tion mass spectrometry,PAMLDI-MS)。该装置将激光解吸附和等离子体辅助离子化技术相组合,并且将其与简单的TLC快速分离结合,对一些小分子混合物进行了分离检测;实验室还借助简单的铅笔芯中石墨涂覆的滤纸作为PAMLDI-MS的进样基底,发现石墨涂覆的滤纸对于待测样品有很好的基质辅助信号增强作用。     

High-throughput screening and machine learning for the efficient growth of high-quality single-wall carbon nanotubes

Nano Research - It has been a great challenge to optimize the growth conditions toward structure-controlled growth of single-wall carbon nanotubes (SWCNTs). Here, a high-throughput method combined...     

基于VMware的Windows Server 2003安装及其网络服务

虚拟机是通过虚拟技术在一台电脑上虚拟出几台电脑,VMware是一款功能强大的桌面虚拟计算机软件。阐述了如何在VMware虚拟机上安装Windows Server 2003及其IIS、DNS、DHCP等网络服务的方法,达到优化实验教学资源的目的,以较少的投入获得较好的教学效果。