ICP-AES法同时测定氯化锂和氢氧化锂中七种杂质元素

本文报导了用ＩＣＰ－ＡＥＳ法同时测定ＬｉＣｌ和ＬｉＯＨ·Ｈ２Ｏ中７种杂质元素Ａｌ、Ｂａ、Ｃａ、Ｆｅ、Ｍｇ、Ｓｉ、Ｚｎ的分析方法。研究了基体元素锂对被测元素的基体效应，采用基体匹配法与背景扣除法进行校正。被测元素的检出限为０．１－９．４ｎｇ／ｍＬ，加标试验回收率为９２％－１０９％，当杂质元素含量为０．０００１％－０．０２８％时，相对标准偏差小于７％。方法简便、快速、准确，用于样品分析，取得了满意的结果。     

电感耦合等离子体质谱法测定高纯镉中的杂质元素

采用电感耦合等离子体质谱法测定高纯镉中的杂质元素。讨论了镉基体的谱线干扰,比较了镉基体产生的多原子离子的干扰程度,该干扰按ＣｄＨ、ＣｄＯ、ＣｄＯ２ 、ＣｄＡｒ、ＣｄＯＨ和ＣｄＯＨ２ 顺序递减。研究了不同浓度镉基体对分析物信号的抑制或增强效应,镉的浓度大于０．２５ｇ·Ｌ－ １ 时,对质量数小于１００的分析物的信号强度产生抑制,而对质量数大于１５０ 的分析物的信号强度产生增强,采用８９Ｙ和２０９ Ｂｉ作内标分别克服基体的抑制和增强效应。测定了高纯镉的Ａｓ、Ｂｅ、Ｃｏ、Ｃｕ、Ｇａ、Ｇｅ、Ｍｎ、Ｍｏ、Ｐｂ、Ｎｉ、Ｓｒ、Ａｕ、Ｔｌ、Ｔｈ、Ｖ 和Ｕ 等１６ 个杂质元素,方法的检测限０．００５～０．０５２ μｇ·Ｌ－ １ ,标准加入回收率８２％ ～１０８％ 。     

ICP—AES法直接测定高纯Eu2O3中14种稀土元素

建立了ＩＰＣ－ＡＥＳ测定高纯Ｅｕ２Ｏ３中１４种稀土元素的方法，用正交设计法优化仪器测量条件，实验了基体Ｅｕ２Ｏ３对被测元素的干扰和对方法测定下限的影响。１４个稀土元素的测定下限为：Ｙｂ２Ｏ３０．５μｇ．ｇ＾－１，Ｙ２Ｏ３１μｇ．ｇ＾－１，Ｄｙ２Ｏ３，Ｈｏ２Ｏ３，Ｔｍ２Ｏ３和Ｎｄ２Ｏ３５μｇ．ｇ＾－１、Ｇｄ２Ｏ３、Ｓｍ２Ｏ３、Ｅｒ２Ｏ３、Ｃｅ２Ｏ３、Ｐｒ６Ｏ１１和Ｌａ２Ｏ３１０μｇ．ｇ＾－１，Ｌｕ２     

电感耦合等离子体质谱法测定高钝镉中的杂质元素

采用电感耦合等离子体质谱光测定离纯镉中的杂质元素。讨论了镉基体的谱线干扰,比较了镉基体产生的多原子离子的干扰程度,该干扰按ＣｄＨ、ＣｄＯ、ＣｄＯ２、ＣｄＡｒ、ＣｄＯＨ和ＣｄＯＨ２顺序递减。研究了不同浓度镉基体对分析物信号的抑制或增强效应,镉的浓度大于０．２５ｇ·Ｌ＾－１时,对质量数小于１００的分析物的信号强度产生抑制,而以质量数大于１５０的分析的信号强度产生增强,采用＾８９Ｙ和＾２０９Ｂｉ作内标分     

TBP色层分离－ICP／AES法测定锆铀铒合金中十七个微量杂质元素和铒

本法对锆铀铒合金中十七个微量杂质元素和铒的测定进行了较系统的实验研究。取样１００ｍｇ时，Ａｌ、Ｃａ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｎ、Ｍｏ、Ｎｉ、Ｐｂ、Ｓｎ、Ｔａ、Ｔｉ、Ｖ、Ｙ和Ｚｎ的测定范围为３０～３２００μｇ／ｇ，Ｅｒ为０．２～３．２％，回收率为９４～１０８％，ＲＳＤ（ｎ＝８）为０．２～２．１％。     

ICP－AES法直接测定高纯Eu_2O_3中14种稀土元素

建立了ＩＣＰ－ＡＥＳ测定高纯Ｅｕ２Ｏ３中１４种稀土元素的方法。用正交设计法优化仪器测量条件，实验了基体Ｅｕ２Ｏ３对被测元素的干扰和对方法测定下限的影响。１４个稀土元素的测定下限为：Ｙｂ２Ｏ３０．５μｇ·ｇ－１，Ｙ２Ｏ３１μｇ·ｇ－１，Ｄｙ２Ｏ３、Ｈｏ２Ｏ３、Ｔｍ２Ｏ３和Ｎｄ２Ｏ３５μｇ·ｇ－１，Ｇｄ２Ｏ３、Ｓｍ２Ｏ３、Ｅｒ２Ｏ３、Ｃｅ２Ｏ３、Ｐｒ６Ｏ１１和Ｌａ２Ｏ３１０μｇ·ｇ－１，Ｌｕ２Ｏ３２０μｇ·ｇ－１以及Ｔｂ４Ｏ７３０μｇ·ｇ－１。加入回收率为８８－１１２％，六次取样分析的相对标准偏差小于１１％。方法简便不经化学分离，可用于９９．９－９９．９９％Ｅｕ２Ｏ３中稀土杂质的测定或生产控制分析。     

ICP-AES法同时测定纯铁中八种杂质元素

本文研究了用ＩＣＰ－ＡＥＳ法同时测定纯铁中８种杂质元素：Ｃｒ、Ｃｕ、Ｍｇ、Ｍｎ、Ｍｏ、Ｎｉ、Ｔｉ、Ｖ的分析方法。研究了铁基体地被测元素光谱线的光谱干扰与物理干扰,采用背景扣除法与基体匹配法进行校正。被测元素的检出限为０．４－３．０μｇ／Ｌ,合成试样的回收率为９１－１１０％,杂持元素含量为０．０００３－０．０５％时,测量的相对标准偏差〈９％,方法简便、准确、结果满意。     

ICP-AES法同时测定硝酸锶晶体中十种掺杂元素

本文报道了用ＩＣＰ－ＡＥＳ法同时测定硝酸锶晶体中掺杂元素Ａｇ、Ｃａ、Ｃｅ、Ｃｕ、Ｆｅ、Ｌａ、Ｍｇ、Ｍｎ、Ｎａ、Ｚｎ的分析方法。本方法采用基体匹配法与背景扣除法对基体干扰及光谱干扰进行校正,被测元素检出限为０．１－１６ｎｇ／ｍＬ,合成样品的回收率为９０％－１１６％。相对标准偏差均小于１３％。本法简便、快速、准确。     

TBP色层分离—ICP／AES法测定锆铀铒合金中十七个微量杂质元…

本法对锆铀铒合金中十七个微量杂质元素和铒的测定进行了较系统的实验研究。取样１００ｍｇ时，Ａｌ，Ｃａ，Ｃｏ，Ｃｒ，Ｃｕ，Ｆｅ，Ｍｇ，Ｍｎ，Ｍｏ，Ｎｉ，Ｐｂ，Ｓｎ，Ｔａ，Ｔｉ，Ｖ，Ｙ和Ｚｎ的测定范围为３０－３２００μｇ／ｇ，Ｅｒ为０．２－３．２％，回收率９４－１０８％，ＲＳＤ为０．２－２．１％。     

原子吸收法测定人精子中锌和铜含量的研究

本文采用石墨炉原子吸收法，以ＮＨ４ＮＯ３和Ｍｇ（ＮＯ３）２混合剂作基体改进剂，测定了人精子中微量元素铜和锌。基方法的特征质量分别为１０．００ｐｇＣｕ／０．００４４Ａ．Ｓ．，９．８０ＰｇＺ／０．００４Ａ．Ｓ；平均加收率为９７．４２％，锌为１０１．９１％，铜和锌的精密度分别是４．１％和４．０３％。     

Al(111)/Al_3Li(111)的界面性质

运用基于第一性原理的平面波贋势法,计算研究了Al (111)/Al_3Li (111)的界面性质.结果表明:Al (111)/Al_3Li (111)的界面具有三种原子配位关系结构,其中界面处仍保持与基体Al一致的三明治堆垛构型的界面稳定性最好.计算表明,该结构界面最薄弱层,位于Al_3Li (111)内,其分离功最小(约1.53 J/m~2),强度最弱,而基体Al和Al_3Li内部的强度随着到界面距离的增大而逐渐增强.     

铸造锌合金中铝、铜、镁、铁、硅、镉的 ICP-AES法测定

采用ICP-AES法测定了铸造锌合金的铝、铜、镁、铁、硅、镉6种元素。并研究了基体对6种被测元素以及被测元素间的干扰。进行了酸度与内标用量试验,以及精密度、准确度、回收率试验,获得了满意的结果。     

Memory element based on ferroelectric field-effect transistor with use of ZnO:Li/LaB6 heterostructures

Ferroelectric field-effect transistors using ZnO:Li films simultaneously as a transistor channel and as a ferroelectric active element have been prepared and studied. We show an opportunity of using the ferroelectric field-effect transistor based on ZnO:Li films in ZnO:Li/LaB₆ heterostructure as a bistable memory element for information recording. The proposed structure of a ferroelectric memory cell does not possess the fatigue under repeated readout of single recorded information that will allow increasing the resource of storage devices essentially.     

锂离子对稀土掺杂氧化物的红外激光诱导热辐射的影响

由于具有较高的可见波段荧光效率,基于稀土掺杂氧化物的红外激光诱导热辐射具有重大的应用潜力。进一步提高红外诱导热辐射效率具有重大的实用价值。设计了一种改善稀土掺杂氧化物材料中红外诱导热辐射效率的方案,即通过掺杂改性杂质,既可以改变稀土离子周围局域晶场的对称性;同时又引入了晶格缺陷。对应的效果包括：一方面,可以通过增强稀土离子周围的晶场强度来提高稀土元素对于入射光子的吸收能力;另一方面,可以利用晶格缺陷作为猝灭中心来增加材料的热转化能力,最终将显著提高杂质改性材料的光热转化效率,即获得更加高效的红外诱导热辐射材料。为了验证设计方案的可行性,利用溶胶-凝胶方法合成了不同浓度的镱离子和锂离子的共掺杂样品,通过XRD及TEM测试分析了杂质对样品结构的影响,并且基于荧光发射光谱具体研究了杂质掺杂浓度对热辐射效率的影响。该工作为高效稀土掺杂热辐射材料的制备提供一定的参考。     

原位能量色散X射线荧光分析中岩样基体效应及其修正研究

原位能量色散X射线荧光现场分析岩样矿物成分时,岩样基体效应会对测量结果产生影响。本文以Cu元素作为待测元素,研究了17种不同岩样基体对原位能量色散X射线荧光分析Cu元素特征X射线强度的影响及其修正方法。采用蒙特卡罗方法模拟获得了Cu元素含量相同的17种不同岩样测量谱线,综合各类岩石元素构成的相似性,并依据模拟谱线Cu元素Kα射线强度与谱线参数之间的相关性,反映了原位能量色散X射线荧光分析岩样Cu元素的基体效应并不完全受岩体元素构成或岩石分类的控制,需要依据岩石样分析谱线参数的相关性进行归类讨论。针对基体影响Cu元素特征射线强度相似的15种岩样进一步研究,并对Cu元素特征X射线与谱线主要参数的主成分进行分析,发现散射本底、X光管靶材料特征X射线及其非相干散射峰强度能够很好的描述Cu元素特征X射线强度受岩样基体影响的变化,据此可以对基体效应影响相似的岩体进行Cu元素测量结果修正。采用本文方法同样也能为不同岩性岩体其他待测元素基体效应的修正提供参考。     

钨盐涂覆-GFAAS法测定肿瘤患者体内痕量锂

钨盐涂覆处理石墨管,大幅度提高测定锂的灵敏度。配以（ＮＨ４）２ＳＯ４基体改进剂,消除生物基体干扰。特征浓度５．５３×１０－３μｇ·ｍＬ－１／１％,回收率大于９３．７２％,相对标准偏差小于８．９３％。     

Modelling the spindle–holder taper joint in machine tools: A tapered zero-thickness finite element method

This study presents a tapered zero-thickness finite element model together with its parameter identification method for modelling the spindle–holder taper joint in machine tools. In the presented model, the spindle and the holder are modelled as solid elements and the taper joint is modelled as a tapered zero-thickness finite element with stiffness and damping but without mass or thickness. The proposed model considers not only the coupling of adjacent degrees of freedom but also the radial, tangential and axial effects of the spindle–holder taper joint. Based on the inverse relationship between the dynamic matrix and frequency response function matrix of a multi-degree-of-freedom system, this study proposes a combined analytical–experimental method to identify the stiffness matrix and damping coefficient of the proposed tapered zero-thickness finite element. The method extracts those parameters from FRFs of an entire specimen that contains only the spindle–holder taper joint. The simulated FRF obtained from the proposed model matches the experimental FRF quite well, which indicates that the presented method provides high accuracy and is easy to implement in modelling the spindle–holder taper joint.     

Ab initio many-body treatment of the electronic structure of metals

We propose and apply a combination of an ab initio (band-structure) calculation with a many-body treatment including screening effects. We start from a linearized muffin-tin orbital (LMTO) calculation to determine the Bloch functions for the Hartree one-particle Hamiltonian, from which we calculate the static susceptibility and dielectric function within the standard random phase approximation (RPA). From the Bloch functions we obtain maximally localized Wannier functions, using a method proposed by Marzari and Vanderbilt. Within this Wannier basis all relevant one-particle and unscreened and screened Coulomb matrix elements are calculated. This yields a multi-band Hamiltonian in second quantization with ab initio parameters, for which screening has been taken into account within the simplest standard approximation. Then, established methods of many-body theory are used. We apply this concept to a simple metal, namely lithium (Li). Here the maximally localized Wannier functions turn out to be of the sp³-orbital kind. Furthermore, only the on-site contributions of the screened Coulomb matrix elements are relevant, and a generalized, four-band Hubbard model is justified. The screened on-site Coulomb matrix elements are considerably smaller than the band width because of which it is sufficient to calculate the selfenergy in weak-coupling approximation. We compare results obtained within the screened Hartree-Fock approximation (HFA) and within the second-order perturbation theory (SOPT) in the Coulomb matrix elements for Li and find that many-body effects are small but not negligible even for this simple metal.     

Tunneling theory of two interacting atoms in a trap

A theory for the tunneling of one atom out of a trap containing two interacting cold atoms is developed. The quasiparticle wave function, dressed by the interaction with the companion atom in the trap, replaces the noninteracting orbital at resonance in the tunneling matrix element. The computed decay time for two ^{6}Li atoms agrees with recent experimental results [G. Zürn, F. Serwane, T. Lompe, A. N. Wenz, M. G. Ries, J. E. Bohn, and S. Jochim, Phys. Rev. Lett. 108, 075303 (2012)], unveiling the "fermionization" of the wave function and a novel two-body effect.     

Structural-acoustic coupling effect on the nonlinear natural frequency of a rectangular box with one flexible plate

The nonlinear natural frequency of a rectangular box, which consists of one flexible plate and five rigid plates, is studied in this paper. The flexible plate is assumed to vibrate like a simple piston. The behavior of the structural-acoustic coupling between the flexible plate and the air cavity is analyzed by using the proposed finite element modal method. The system finite element equation is reduced and expressed in terms of the modal coordinates with small degrees of freedom by using the proposed reduction method. The system nonlinear stiffness matrix representing the large amplitude vibration can be transformed to be a constant modal matrix. The natural frequencies are determined by using the harmonic balance method to solve the eigenvalue equations of the structural-acoustic system. The effect of the cavity depth on the natural frequencies and convergence studies are discussed in detail.