Sb-Na共掺p型ZnO的第一性原理研究

运用密度泛函理论,计算了Sbzn、Nazn、Sbzn-nNazn掺杂ZnO晶体的稳定性、能带结构和电子态密度.研究发现Sbzn、Nazn、Sbzn-nNazn掺杂ZnO晶体的结构稳定,Sb-Na共掺杂改善了体系的固溶度.能带结构表明,SbZn体系为n型间接带隙半导体材料;NaZn、Sbzn-2NaZn体系为p型半导体材料;Sbzn-NaZn、SbZn-3NaZn体系为本征半导体材料.对p型半导体材料体系的导电性能研究发现,Sbzn-2Nazn体系电导率大于NaZn体系的电导率,即Sbzn-2NaZn掺杂改善了体系的导电性.计算结果为实验制备p型ZnO材料提供了理论指导.     

Identification of surface oxygen vacancy-related phonon–plasmon coupling in TiO_2 single crystal

Oxygen vacancies(OVs) play a critical role in the physical properties and applications of titanium dioxide nanostructures, which are widely used in electrochemistry and photo catalysis nowadays. In this work, OVs were artificially introduced in the surface of a pure TiO_2 single crystal by pulsed laser irradiation. Raman spectra showed that the intensity of E_g mode was enhanced. Theoretical calculations disclose that this was caused by the strong coupling effect between the phonon vibration and plasmon induced by the OVs-related surface deformation, and good agreement was achieved between the experiments and theory.     

激光快速成形Inconel 718超合金拉伸力学性能研究

研究了激光快速成形Inconel 718超合金试样3个相互垂直方向的拉伸力学性能,以及热处理对激光快速成形凝固组织与3个相互垂直方向拉伸力学性能的影响。结果表明,激光快速成形Inconel 718超合金试样3个相互垂直方向的拉伸力学性能均明显低于其锻件拉伸力学性能,且表现出明显的各向异性。经过热处理的Inconel 718超合金试样,其沿沉积高度方向定向外延生长的柱状枝晶组织转变为晶粒粗大且不均匀的等轴状再结晶组织,随Laves相固溶消失及强化相γ″和γ′大量析出,3个相互垂直方向上的拉伸力学性能均大幅度提高,其中,与基板平行的两个相互垂直方向上的拉伸力学性能均达到Inconel 718超合金锻件拉伸力学性能标准,但沿成形件高度方向,出现拉伸力学性低于Inconel 718超合金锻件拉伸力学性能标准的试样。     

云计算总体架构及其应用与商业模式探讨

云计算具有全新的IT架构,可以灵活提供服务给具有不同需求的用户。通过对云架构的研究,指出云架构主要分为服务和管理两部分,详细解析了软件即服务（SaaS）、平台即服务（PaaS）和基础设施即服务（IaaS）及其实现的关键技术,以及管理部分客户层、管理功能层和监控层的架构和功能实现。最后,面向应用,给出了具体云计算构架的实例,并结合应用,提出了云应用的4种商业模式,即公有云、私有云、行业云和混合云,对云服务供应商面向客户的运营选取有一定的指导作用。     

高效数据中心助中小企业快速部署

艾尼科环保技术(中国)有限公司源于美洲最大的大气污染治理公司--美国环境技术公司,拥有美国环境技术公司全套干法脱硫、静电除尘、布袋除尘等大气污染控制技术在中国的使用权和技术合作权,并能得到美国环境技术公司完整的技术支持和质量     

Switching plasticity in compensated ferrimagnetic multilayers for neuromorphic computing

Current-induced multilevel magnetization switching in ferrimagnetic spintronic devices is highly pursued for the application in neuromorphic computing. In this work, we demonstrate the switching plasticity in Co/Gd ferrimagnetic multilayers where the binary states magnetization switching induced by spin-orbit toque can be tuned into a multistate one as decreasing the domain nucleation barrier. Therefore, the switching plasticity can be tuned by the perpendicular magnetic anisotropy of the multilayers and the in-plane magnetic field. Moreover, we used the switching plasticity of Co/Gd multilayers for demonstrating spike timing-dependent plasticity and sigmoid-like activation behavior. This work gives useful guidance to design multilevel spintronic devices which could be applied in high-performance neuromorphic computing.     

Impact of AlxGa1-xN barrier thickness and Al composition on electrical properties of ferroelectric HfZrO/Al2O3/AlGaN/GaN MFSHEMTs

Ferroelectric (FE) HfZrO/Al$_{2}$O$_{3}$ gate stack AlGaN/GaN metal-FE-semiconductor heterostructure high-electron mobility transistors (MFSHEMTs) with varying Al$_{x}$Ga$_{1-x}$N barrier thickness and Al composition are investigated and compared by TCAD simulation with non-FE HfO$_{2}$/Al$_{2}$O$_{3}$ gate stack metal-insulator-semiconductor heterostructure high-electron mobility transistors (MISHEMTs). Results show that the decrease of the two-dimensional electron gas (2DEG) density with decreasing AlGaN barrier thickness is more effectively suppressed in MFSHEMTs than that in MISHEMTs due to the enhanced FE polarization switching efficiency. The electrical characteristics of MFSHEMTs, including transconductance, subthreshold swing, and on-state current, effectively improve with decreasing AlGaN thickness in MFSHEMTs. High Al composition in AlGaN barrier layers that are under 3-nm thickness plays a great role in enhancing the 2DEG density and FE polarization in MFSHEMTs, improving the transconductance and the on-state current. The subthreshold swing and threshold voltage can be reduced by decreasing the AlGaN thickness and Al composition in MFSHEMTs, affording favorable conditions for further enhancing the device.     

冰的熔解热实验中冰水质量比的探讨

冰与温水质量比对冰的熔解热实验的成败起着关键作用。文章对冰水质量比进行测量和分析,得出了冰的熔解热实验中最适合的冰水质量比的范围约为1／12-1／5。     

采用吸收修正Bronnikov算法的有机复合样品的X射线显微计算机层析研究

有机复合样品如大多数由低原子序数物质构成的多聚物组合材料、生物软组织等具有混合相位和振幅特性,采用传统吸收计算机层析(CT)或纯相位重构算法难以达到较高密度分辨的目的。采用基于吸收修正的Bronnikov相位恢复算法的X射线同轴相衬CT技术对高分子混合组份材料和药物医学样品进行了实验研究。结果表明该相位恢复算法可以实现多聚物组合材料的无损分辨和精确测量,能够清晰辨别各组份材料的电子密度分布;验证了药物样品多孔性结构三维测量的可行性,能够有效提供孔隙测量的阈值选择。该方法在材料科学尤其是聚合物组合材料、泡沫多孔材料都会发挥很好的作用;单距的低辐射优势,尤其适用于生物医学样品三维无损成像。     

“弦振动的研究”实验仪器的改进

指出了“弦振动的研究”实验仪器存在的问题,提出了改进方法。