从拉格朗日函数的不确定性导出定域规范不变性

从拉格朗日函数的不确定性出发，通过作为积分上发的坐标函娄之作用量Ｓ＝∫ｔｔ１Ｌｄｔ′＝Ｓ（ｘ＾μ）及其不确定性，得到ψ与ψ′＝ｅ＾－ｉｑａ（ｘ＾μ）ψ等效－定域规范不变性或日局域对称性。     

N2分子X^1Σg^＋,A^3Σu^＋和B^3Пg的势能函数

用文献［１，２，８］介绍的方法推导了Ｎ２分子的基态（Ｘ＾１Σｇ＾＋）的激发态（Ａ＾３Σｕ＾＋和Ｂ＾３Пｇ）的合理离解极限。计算并比较了在６－３１１Ｇ＾＊基集合，ＵＨＦ、ＣＩＤ、ＵＣＩＳＤ和ＱＣＩＳＤ水平下Ｎ２分子上述三个电子态的平衡结构和谐振频率；并用ＱＣＩＳＤ／６－３１１Ｇ＾＊计算了各态的系列单点势能值，由正规方程组拟合Ｍｕｒｒｅｌｌ－Ｓｏｒｂｉｅ函数得到了相应各态的完整势能函数，结果与实验数计     

PuO2体系的分子反应动力学研究

基于ＰｕＯ２分子（Ｘ＾５Σｇ＾＋）的多体展式分析势能函数,用准经典的Ｍｏｎｔｅ－Ｃａｒｌｏ轨迹法研究了Ｏ（＾３Ｐｇ）＋ＰｕＯ（０,０）和Ｐｕ（＾７Ｆｇ）＋Ｏ２（０,０）的分子反应动力学过程。结果表明：Ｏ（＾３Ｐｇ）＋ＰｕＯ（０,０）碰撞生成少量稳定络合物ＰｕＯ２（Ｘ＾５Σｇ＾＋）,该反应是无阈能反应;而Ｐｕ（＾７Ｆｇ）＋Ｏ２（０,０）碰撞生成稳定络合物的同时,主要还发生了Ｐｕ（＾７Ｆｇ）＋Ｏ２（０     

HF的电子态X^1Σ^＋和B^1Σ^＋之势能函数和△ν=2泛频跃迁…

用Ｍｕｒｒｅｌｌ－Ｓｏｒｂｉｅ函数表述ＨＦ（Ｘ＾１Σ＾＋和Ｂ＾１Σ＾＋）的势能函数。通过对ＨＦ振转能级的计算，得到△ν＝２泛频跃迁精细结构，所得结果中，基态之Ｐ支与Ｗ．Ｑ．Ｊｅｆｆｅｒｓ发表的实验结果进行了比较。     

Thomas-Reiche-Kuhn求和规则的推广

Ｔｈｏｍａｓ－Ｒｅｉｃｈｅ－Ｋｕｈｎ求和规则是对算符ｘ或ｅｉｋｘ而言的．本文给出了下列算符普遍形式所适用的求和规则：Ⅰ．Ｆ＝Ｆ（ｘ）；Ⅱ．Ｆ＝Ｆ（ｐ）；Ⅲ．Ｆ＝Ｆ（ｘ，ｐ）是ｘ和ｐ的整函数．     

铁酸盐的水热氧化晶化法制备及其生成条件研究

研究了空气氧化Ｍ＾２＋（Ｍ＝Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ）和Ｆｅ＾２＋的碱性悬浮液制备铁酸盐ＭＦｅ２Ｏ４的条件，考察了原料配比、ｐＨ值、氧化温度、氧化时间对生成ＭＦｅ２Ｏ４的影响。利用ＸＲＤ及ＳＥＭ检测氧化过程中沉淀物的形态和结构表明，在３４３￣３５８Ｋ和Ｒ＝２ＯＨ＾－／（Ｍ＾２＋Ｆｅ＾２＋）＝１．０、Ｍ＾２／Ｆｅ＾２＋＝０．５（摩尔比）下用３００ｍＬ／ｈ的空气氧化Ｍｘ／３Ｆｅ１－ｘ／３（ＯＨ）２悬浮液     

发光体Mg2Y8—x—y（SiO4）6O2：Eux^3^＋,Biy^3^＋的形成过程及发光…

采用Ｓｏｌ－Ｇｅｌ方法首次在比较低的温度下制氧磷灰石结构的发光体Ｍｇ２Ｙ８－ｘ－ｙ（ＳｉＯ４）６Ｏ２：Ｅｕｘ＾３＾＋，Ｂｉｙ＾３＾＋（ｘ，ｙ≥０），利用ＸＲＤ，ＩＲ，ＴＧ－ＤＴＡ三种手段研究了发光体的形成过程。室温（２９３Ｋ）和液氮温度（７７Ｋ）的荧光光谱表明Ｅｕ＾３＾＋和Ｂｉ＾３＾＋在这种基质中分别发射红光和蓝光，每ｍｏｌ基质中其最佳掺杂浓度分别为０．１４ｍｏｌ和０．０３ｍｏｌ，并且其发光都存在     

多模气体激光纵模线型函数及其频宽的实验观测

本文根据多模激光时间相干性ｇ（１）（τ）的准周期性特点，提出了一种观测多模激光纵模线型函数及其频宽的新方法－程差２ｋＬ法。文章介绍了测量原理与方法，并以双模Ｈｅ－Ｎｅ激光器为例，给出了相应的实验结果，研究表明，多模气体激光的纵模线型函数为洛仑兹（Ｌｏｒｅｎｔｚ）线型函数，相应的纵模频宽约为１０＾７Ｈｚ。     

气固界面氧化学吸附物种的动态研究

用自编的傅里叶变换红外（ＦＴ－ＩＲ）动态谱批处理程序，在２０－６５０℃对Ｂｅ，Ｍｇ，Ｃａ，Ｌａ，Ｃｅ，Ｓｍ，Ｔｉ，Ｚｒ，Ｖ，Ｎｂ，ｃＲ，Ｍｏ，Ｗ，ＭＮ，Ｆｅ，Ｎｉ，Ｃｕ，Ｚｎ和Ｓｎ等一系列金属氧化物上的氧化学吸附物种进行了原位动态三维谱学研究，就所观测到的超氧（Ｏ＾－２）和过氧（Ｏ＾２－２）物种随温度的变化情况以及甲烷氧化偶联催化反应中的活性氧物种进行了讨论。     

稀磁半导体Cd_（1－x）Fe_xTe的磁光光谱

在７０－３００Ｋ温度范围内测量了组分ｘ为０．０１和０．０４的Ｃｄ１－ｘＦｅｘＴｅ及ＣｄＴｅ的法拉第效应随入射光子能量的变化，首次获得了Ｃｄ１－ｘＦｅｘＴｅ在布里渊区Γ点和Ｌ点的有效ｇ因子及其与温度的关系。给出了Ｆｅ２＋离子与载流子间的ｓｐ－ｄ交换作用常数Ｎ０（β－α）＝（－１．５７±０．０３）ｅＶ。     

Glasslike two-level systems in minimally disordered mixed crystals

THz spectroscopy is used to identify a broad distribution of two-level systems, characteristic of glasses, in the substitutional monatomic mixed crystal systems, Ba(1-x)Ca(x)F(2) and Pb(1-x)Ca(x)F(2). In these minimally disordered systems, two-level behavior, which was not previously known to occur, begins at a specific CaF(2) concentration. The concentration dependence, successfully modeled using the statistics of the impurity distribution in the lattice, points to a collective dopant tunneling mechanism.     

On the long-run average growth rate of chaotic systems

For a discrete dynamical process defined by Xt=F(X(t-1),X(t-2),...,X(t-k)), where Xt subset R+n, the growth rate for the ith endogenous variable is conventionally defined as g(it) identical with (x(it+1)-x(it))/x(it). It is shown that, when the trajectories of x(it) exhibit periodic or aperiodic (chaotic) fluctuations within a bounded range, the long-run average growth rates are always positive, that is, g(it) identical with lim(T--> infinity )1/TSigmaTt=1 g(it) > 0, for all i, so as to induce an illusion of growth. The fact is generic in the sense of being irrespective of the dynamic structure of F. Moreover, the same characteristic exists even if the process is reversed. Economic implications and applications are discussed. It is concluded that the statistical inequalities provide additional measures to check the validity of different discrete models or to test different specifications from empirical time series.     

Antiferromagnetic spin fluctuations above the dome-shaped and full-gap superconducting states of LaFeAsO1-xFx revealed by (75)As-nuclear quadrupole resonance

We report a systematic study by (75)As nuclear-quadrupole resonance in LaFeAsO(1-x)F(x). The antiferromagnetic spin fluctuation found above the magnetic ordering temperature T(N) = 58 K for x = 0.03 persists in the regime 0.04 ≤ x ≤ 0.08, where superconductivity sets in. A dome-shaped x dependence of the superconducting transition temperature T(c) is found, with the highest T(c) = 27 K at x = 0.06, which is realized under significant antiferromagnetic spin fluctuation. With increasing x further, the antiferromagnetic spin fluctuation decreases, and so does T(c). These features resemble closely the cuprates La(2-x)Sr(x)CuO(4). In x = 0.06, the spin-lattice relaxation rate (1/T(1)) below T(c) decreases exponentially down to 0.13T(c), which unambiguously indicates that the energy gaps are fully opened. The temperature variation of 1/T(1) below T(c) is rendered nonexponential for other x by impurity scattering.     

Absence of conventional spin-glass transition in the Ising dipolar system LiHo(x)Y(1-x)F(4)

The magnetic properties of single crystals of LiHo(x)Y(1-x)F(4) with x = 16.5% and x = 4.5% were recorded down to 35 mK using a micro-SQUID magnetometer. While this system is considered as the archetypal quantum spin glass, the detailed analysis of our magnetization data indicates the absence of a phase transition, not only in a transverse applied magnetic field, but also without field. A zero-Kelvin phase transition is also unlikely, as the magnetization seems to follow a noncritical exponential dependence on the temperature. Our analysis thus unmasks the true, short-ranged nature of the magnetic properties of the LiHo(x)Y(1-x)F(4) system, validating recent theoretical investigations suggesting the lack of phase transition in this system.     

Band gap and electronic structure of an epitaxial, semiconducting Cr0.80Al0.20 thin film

Cr(1-x)Al(x) exhibits semiconducting behavior for x = 0.15-0.26. This Letter uses hard x-ray photoemission spectroscopy and density functional theory to further understand the semiconducting behavior. Photoemission measurements of an epitaxial Cr(0.80)Al(0.20) thin film show several features in the valence band region, including a gap at the Fermi energy (E(F)) for which the valence band edge is 95 ± 14 meV below E(F). Theory agrees well with the valence band measurements, and shows an incomplete gap at E(F) due to the hole band at M shifting almost below E(F).     

Randomly diluted eg orbital-ordered systems

Dilution effects on the long-range ordered state of the doubly degenerate e(g) orbital are investigated. Quenched impurities without the orbital degree of freedom are introduced in the orbital model where the long-range order is realized by the order-from-disorder mechanism. It is shown by Monte Carlo simulations and the cluster-expansion method that a decrease in the orbital-ordering temperature by dilution is substantially larger than that in the randomly diluted spin models. Tilting of orbital pseudospins around impurities is the essence of this dilution effect. The present theory provides a new viewpoint for the recent resonant x-ray scattering experiments in KCu(1-x)Zn(x)F(3).     

Effective Hamiltonian for Ga1-x MnxAs in the dilute limit

We derive an effective Hamiltonian for Ga(1-x)Mn(x)As in the dilute limit, where Ga(1-x)Mn(x)As can be described in terms of spin F=3/2 polarons hopping between the Mn sites and coupled to the local Mn spins. We determine the parameters of our model from microscopic calculations. Our approach treats the large Coulomb interaction in a nonperturbative way, captures the effects of spin-orbit coupling and disorder, and is appropriate for other p-doped magnetic semiconductors.     

白宝石衬底上生长的MgxZn1-xO晶体薄膜的结构和光学性能

在白宝石 (sapphire)衬底上低温外延生长出了MgxZn1 -xO晶体薄膜 .x射线衍射 (XRD)及能量色散x射线 (EDX)分析表明 ,MgxZn1 -xO薄膜的晶体结构依赖于薄膜中Mg的组分x,随着Mg组分的增大 ,MgxZn1 -xO薄膜的结构从与ZnO晶体一致的六方结构转变为与MgO晶体一致的立方结构 .对MgxZn1 -xO薄膜的紫外透射光谱及紫外光致荧光谱 (UVPL)的分析表明 ,随着Mg组分的增大 ,光学吸收边产生明显的蓝移 ,表明MgxZn1 -xO晶体薄膜的带隙增大 ,且带隙连续可调 .吸收光谱和XRD测量显示 ,带隙高达 5 6 5eV的MgxZn1 -xO晶体薄膜与MgO之间的晶格失配仅为0 16 % .     

Common energy scale for magnetism and superconductivity in underdoped cuprates: a muon spin resonance investigation of (Ca(x)La(1-x)) (Ba(1.75-x)La(0.25+x))Cu3O(y)

We characterize the spontaneous magnetic field, and determine the associated temperature T(g), in the superconducting state of (Ca(x)La(1-x)) (Ba(1.75-x)La(0.25+x)) Cu(3)O(y) using zero and longitudinal field muon spin resonance measurements for various values of x and y. Our major findings are (i) T(g) and T(c) are controlled by the same energy scale, (ii) the phase separation between hole poor and hole rich regions is a microscopic one, and (iii) spontaneous magnetic fields appear gradually with no moment size evolution.     

Lithium/Silver-Doped Cu_2ZnSnS_4 with Tunable Band Gaps and Phase Structures: a First-Principles Study

Doping is an effective approach for improving the photovoltaic performance of Cu_2 ZnSnS_4(CZTS). The doping by substitution of Cu atoms in CZTS with Li and Ag atoms is investigated using density functional theory. The results show that the band gaps of Li_(2 x)Cu_(2(1-x))ZnSnS_4 and Ag_(2 x)Cu_(2(1-x))ZnSnS4 can be tuned in the ranges of 1.30-3.43 and 1.30-1.63 eV, respectively. The calculation also reveals a phase transition from kesterite to wurtzite-kesterite for Li_(2 x)Cu_(2(1-x))ZnSnS_4 as x is larger than 0.9. The tunable band gaps of Li_(2 x)Cu_(2(1-x))ZnSnS_4 and Ag_(2 x)Cu_(2(1-x)) ZnSnS_4 make them beneficial for achieving band-gap-graded solar cells.