Raman and IR spectra of noncentrosymmetric Bi0.21La0.91Sc2.88(BO3)4 single crystal with the huntite‐type structure

Single crystals of optical nonlinear borate, Bi_0.21La_0.91Sc_2.88(BO₃)₄, were grown and polarized Raman and IR spectra were recorded for this material at room temperature. The spectra have been discussed on the factor group approach for the trigonal R32 (D₃⁷) space group with Z = 3. The assignment of the observed bands to the respective internal and lattice modes is proposed. Copyright © 2010 John Wiley & Sons, Ltd.     

ICP-AES法测定铝合金中的Sc

本文采用ICP－AES法测定铝合金中的Sc，并讨论了基体元素及共存元素对Sc的干扰，进行了酸度试验，采用盐酸和硝酸溶解试样，回收率为96．0％－101．0％，RSD为0．31％－0．59％，方法简便，可靠，可获得满意的分析结果。     

Al-4Mg-Sc-Zr四元系富Al角430 ℃相关系

通过显微组织观察、X射线衍射分析和电子探针分析测定Al-4Mg-Sc-Zr四元系富Al角430℃等温截面的相关系。结果表明：在扩大的Al-4Mg-Sc-Zr四元430℃等温截面图中存在一个单相区、两个双相区和一个三相区。具有L12型结构的Al3Sc1-0.5Zr0-0.5相和具有DO23型结构的Al3Zr1-0.8Sc0-0.2相与α（Al）固溶体在平衡状态下共存,其中Zr在Al3Sc中的最大溶解度可达12.5%（原子分数）,在Al3Zr中最多可溶解5.0%（原子分数）的Sc。     

Electronic properties,quantum capacitance and photocatalyst for water splitting of Sc2CO2 MXene under uniaxial strain

MXenes have wide applications because of the structural flexibility and compositional diversity. Quantum capacitance, electronic and photocatalytic properties of Sc₂CO₂ monolayer under uniaxial strains are investigated by first-principles calculation. Sc₂CO₂ monolayer can withstand stress up to 13.96 N/M and about 14% tensile uniaxial strain limit. Sc₂CO₂ undergoes a transition from semiconductor to metal at −15% uniaxial strain. Sc₂CO₂ under uniaxial strains are only used for the water reduction at pH = 0. Sc₂CO₂ under uniaxial strains of −10%, −7%, −3%, 0%, and 4% within the appropriate pH scope are potential photocatalysts for water redox reaction. Sc₂CO₂ with −15% uniaxial strain is promising anode material, and Sc₂CO₂ with tensile uniaxial strain is more potential cathode material. Wide voltage improves the top quantum capacitance at negative bias under uniaxial strain and keeps the type of electrode materials. Quantum capacitance of Sc₂C with mixed termination (Sc₂CO_0.59F_1.19(OH)_0.22) under uniaxial strain is explored. The introduction of uniaxial strain and mixed termination has little effect on the electrode type of Sc₂CO₂ MXene.     

Sc2O3电子结构和光学性质的第一性原理研究

本文基于第一性原理平面波赝势(PWP)和广义梯度近似(GGA)方法,研究了Sc2O3的电子结构、态密度和光学性质. 计算结果表明：Sc2O3是一种直接带隙半导体,其能带宽度为3.79eV,价带顶部主要由O的2p和Sc的3p3d杂化而成,导带主要由Sc的3d和O的2p构成. 同时,文中也分析了Sc2O3的介电函数、折射率、光电导率和吸收谱等光学性质. 计算得到静态介电常数 ,折射率n0=1.25,在紫外区有较大的吸收系数.     

铜铁试剂沉淀杂质ICP-AES测定地球化学样品中的稀土和钪

铜铁试剂是一种良好的沉淀剂。在5～10%的盐酸介质中,它能有效地沉淀Fe、Ti、Zr等,消除了测定过程中的光谱干扰。配以ICP-AES法测定稀土元素,其精密度和准确度均能满足地球化学样品分析的需要。此法对测稀土元素和钪非常有效。     

金属Sc对Ti-6Al-4V合金组织演变与性能的影响

采用真空电弧熔炼技术制备了含Sc(质量分数)为0,0.1%,0.3%,0.5%的4种Ti-6Al-4V合金,并利用X射线衍射技术、光学金相显微镜和SHIMADZU HMV硬度计对铸态合金的相组成、等温退火后进行淬火的合金的显微组织和显微硬度进行研究.研究结果表明:在合金的铸态组织中存在大量的类魏氏组织,添加金属Sc减小了魏氏组织的含量与尺寸;经过等温退火及淬火处理后,在合金组织中存在细针状的马氏体组织和少量的类魏氏体组织,同时,随着退火温度的降低,组织中针状马氏体尺寸减小,金属Sc对合金组织起明显的细化作用;在铸态合金中存在的相为Ti3Al,添加金属Sc使α-Ti在低角度的衍射峰强度变弱,在高角度的衍射峰强度变强;添加金属Sc导致Ti-6Al-4V合金片层组织的显微硬度大幅度提高,当Sc含量在0.1%～0.3%时,其显微硬度最适宜;退火态合金的显微硬度比铸态合金的显微硬度提高了很多;金属Sc对α-Ti的固溶强化效果最明显.     

Evidence for a K<Superscript>π</Superscript> = 1/2<Superscript>+</Superscript> isomer in neutron-rich <Superscript>185</Superscript>Ta

In this paper we present for the first time the measured delayed neutron (DN) yields and time spectra from high-energy protons interacting with thick ^natPb targets. The 1GeV protons from the accelerator impinged on targets of different thicknesses producing a huge number of spallation-fission products, some of which can be DN precursors. After the beam is switched off, the DNs were detected with optimized ³He counter. The production yields of light DN precursors as ¹⁷N and “usual” fission products as ⁸⁷Br and ⁸⁸Br, which dominate the total DN activity, are obtained both for thin and thick targets. These new data are of great interest for the new generation high-power spallation targets based on liquid-metal technologies. Our findings also should help to constrain the physics models within the simulations codes.