吡啶B1(nπ*)态(2+3)偏振共振多光子电离谱中6a10带型模拟及转动常量确定

通过模拟吡啶B₁(nπ^*)态(2+3)偏振共振多光子电离谱中转动结构可部分分辨的6a¹₀带型,获得了该态上吡啶分子的转动常量,分别为A′=0.21670cm^-1,B′=0.16758cm^-1,C′=0.09450cm^-1.表明氮原子上的一个孤对电子跃迁进入π^*轨道后氮原子自身电负性减弱,吡啶分子构架总体上张开.此外,比较6a^关键词：     

高Tc氧化物超导体Bi(Pb)-Sr-Ca-Cu-O(F)的“不可逆线”

研究了高T_c氧化物超导体Bi(Pb)-Sr-Ca-Cu-O(F)体系的“不可逆线”。发现不可逆磁场H^*<120Oe时,H^*=1590(1—t)^3/2;当120Oe*<1000Oe时,H^*=35700(1—t)^3/2-2480。指出H^*(T)曲线是一个磁通格子熔化线,在曲线以下属于磁通蠕动区;在H^*(T)与H_c2(T)之间属于磁通格子液态区,即磁通流动区。 关键词：     

TWO PHOTONS EXCITED 4d RYDBERG STATE OF AsH3

In this paper, by using resonance enhanced (2+1) multiphoton ionization (REMPI) of AsH₃ and detecting the daughter molecular ions AsH⁺ and As⁺, a long progression discrete structure was obtained from 267 to 291 nm, which obeys the formula ν₀(cm^-1)=68875.3+504.1v′₂+5.26v′²₂. Analysis of the spectrum has revealed that it belongs to 4d Rydberg state transition. Our assignment yields the 4d Rydberg state parameters T_e′=67881.1 cm^-1, ω_e′=495.1 cm^-1 and δ=0.962. Finally the 4d Rydberg state structure of AsH₃ was discussed.     

非晶锂离子导体B2O3-Li2O-LiCl一Al2O3中VO2+的电子自旋共振

两种非晶锂离子导体B₂O₃-0.7Li₂O-0.7LiCl-xAl₂O₃-0.1V₂O₅(x=0.05和0.15)的电子自旋共振谱研究表明:(i)ESR线型是高斯型,证实V₂O₅添加量适当;(ii)超精细结构来源于VO²⁺络离子,具有四角对称性,属C_4v群。越精细耦合张量的平行分量平均值A_//=0.0175cm^-1,垂直分量A_⊥=0.0063cm^-1。由g_//(g_⊥)求出其基态²B_2g与第一激发态²E_g的能级间距△₁=2.46×10⁴ cm^-1,基态与第二激发态²B_1g的能级间距△₂=3.03×10⁴ cm^-1;(iii)变温实验证实:Al₂O₃组分较少(x=0.05)的非晶ESR强度比x=0.15的非晶高3倍至2倍,而Al₂O₃组分越多则ESR强度随温升下降越小。     

S2分子B″3Πu态的势能函数和光谱常数的理论研究

推导了S₂分子B″³Π_u态的合理离解极限.用Gaussian 94 QCISD(T)方法和6-311++G^**基组计算了S₂分子B″³Π_u以及X³Σ^-_g态的势能曲线.给出了S₂分子B″³Π_u态的Murrell-Sorbie势能函数和光谱常数.B″³Π_u与B³Σ^-_u态在排斥支重叠范围大；同时，B″³Π_u与X³Σ^-_g态有相同离解极限，因而，在吸引支有重叠.讨论了B″³Π_u与B³Σ^-_u和X³Σ^-_g态相互作用的特征. 关键词：     

传输线模型测量Au/Ti/p型金刚石薄膜的欧姆接触电阻率

采用传输线模型测量了重B掺杂p型金刚石薄膜(约10²⁰cm^-3)上Ti/A u欧姆接触电阻率ρ_c,测试了500℃退火前后及大电流情况下的I-V特性,研究 了退火对ρ_c的影响.结果表明,重掺杂和退火工艺是改善欧姆接触的有效手段. ρ_c随测试温度的变化表明金属/半导体接触界面载流子输运机制为隧道穿透.而 光照对ρ_c影响的分析表明金刚石可作为理想窗口材料.测试得到的最低ρ _c值约为10^-4Ωcm². 关键词： 金刚石薄膜 欧姆接触 接触电阻率     

Rb(62D)原子与基态Rb原子,H2分子碰撞转移截面

本文用荧光法测量Rb(6²D)原子与基态Rb原子,H₂分子碰撞转移截面。结果表明:Rb(6²D)-Rb(5²s)转移截面为σ_fs=67×10^-14cm²,σ_tr=4.3×10^-14cm²,Rb(6²D)—H₂转移截面为σ_fs 关键词：     

片状铌酸锂单晶的生长及其特性

采用润湿导模技术生长出大块的片状铌酸锂单晶,尺寸可达200mm长、20mm宽、3mm厚。经测试,性能与柱状单晶相同。为了做好此项工作,我们测定了铌酸锂熔体的密度ρ_m与表面张力α等物理常数,得出在1270℃时ρ_m=3.57×10³kg/m³,α=204dyne/cm;在1300℃时ρ_m=3.42×10³kg/m³,α=192dyne/cm。 关键词：     

关于一级近似Tc级数解的收敛问题

本文通过一个实例说明:μ^*=0时,一级近似T_c级数解的收敛半径既不是由z_ph=-∫₀^(ω_ph)dωg(ω)dω·ω²/(ω_ph²-ω²),也不是由z_ph=∫₀^(ω_ph)dωg(ω)dω·ω^{2< 关键词：}     

关于超导临界温度级数收敛半径的一个注记

本文指出,对于实际的归一化有效声子谱函数g(ω),一般来说,z_ph≡F(-ω_ph^-2是函数z=F(y)≡∫₀^(ω_ph)(ω²y)/(ω²y+1)g(ω)dω的反函数的分支点。因此,在估算超导T_c级数的收敛半径时,应当予以考虑。 关键词：     

Deformation of Superoperator's Kraus Representation Derived by Weyl Correspondence and Entangled State Representation

By virtue of the Weyl correspondence and based on the the technique of integration within an ordered product of operators, we show under what condition the superoperator's Kraus representation ρ^ˊ=∑_μ A_μρA_μ^† can be deformed as ρ^ˊ=(1/π)∫d²αB(α)D(α)ρD^†(α), where D(α) is the displacement operator, B(α) is a probability density related to the classical Weyl correspondence of A_μ. An alternate discussion by using the entangled state representation and through a quantum teleportation process is also presented.     

热阴极电离真空计的线性理论

从繁流放电理论可直接导出热阴极电离真空计的特性方程,证明通常的概念即在热计的电子流i_e一定时其离子流i₊与压强P成正比的关系,只在离子流甚小于电子流时才能成立。在被测气体的压强较高时,离子流和压强之间呈现下列指数关系: i₊/i_e=1-e^{(-(K₁P-K₂P2))}(K₁及K₂为常数),且随着压强的增长而逐步趋于饱和。进一步的推导则得出,当容许测量误差为1％时,热计的线性上限(临界压强)为P_c=0.22/Г,此处Г为热计的灵敏度。这种理论可以容易地解释近年来一些实验工作者例如Nottingham,Schultz,Goto,Hinzpeter等的实验结果。此外我们还使用了特殊设计的“封闭式”电离计作实验,得到的结果和理论预计十分符合。这种电离计本身则可用作10^-7～0.6托的宽程量具。 关键词：     

缩胺基脲和缩硫代胺基脲的核磁共振研究

本文研究了十二个缩胺基脲和缩硫代胺基脲化合物的¹H,¹³C核磁共振谱。指出芳环¹³C及¹H的δ_c和δ_H分别服从δ_c(1)=δ_c(0)+∑_js_ji及δ_H=7.41-∑s公式,而且δ_c与Hammett常数σ_p,π-电子云密度ρ_x以及δ_H-5ρ_p均有良好的线性关系。缩硫代胺基脲化合物具有一定的抗结核生物活性,而缩胺基脲化合物完全无此性质。同时,缩硫代胺基脲化合物的抗结核活性及其伴生的毒性又与母体羰基化合物的结构有关,因此引起人们一定的关注,并用X光衍射,电子吸收光谱,振动光谱等方法对此两类化合物的结构与性能间的关系进行了研究。但迄今为止,此两类化合物的¹³C NMR工作尚未见诸报道,¹H NMR的研究也比较少。为此,我们对这两类化合物¹³C NMR和¹H NMR进行了较系统的研究。这不仅为测定此两类未知化合物结构提供判据,而且对深入了解波谱参数和结构,以及结构与性能之间的联系亦是有益的。     

真空紫外区Ar的高次离化光谱的研究

本文报道了波长在2000—194?真空紫外区域内Ar的高次离化光谱工作。观察到相当数量的新谱线,并归属了其中64条,还找到六个新能级,即:ArIV 3s²3p²(³P)3d²F_5/2,7/2, ArIV 3s²3p²(¹D)3d²S_1/2, ArV3s²3p3d关键词：     

THE CONVERSION OF GLUONS INTO QUARKS AND THE MULTIQUARK STATES

The rate for the conversion of the gluon into a color octet quark pair which subsequently forms a multiquark state with another quark pair or a gluon is discussed. The static potential in a [(QQ)₈(qq)_8,1] state where Q=c,b and q=u, d is studied in the MIT bag model. It is shown that the repulsive Coulomb force between Q and Q is dominant at small QQ separations, which would significantly suppress the QQ wave function at the origin. For the charm quark (Q=c) the ratio of |Ψ(O)|² for the ordinary (QQ)₁ to that for the(QQ)₈ in the [(QQ)₈(qq)_8,1] state is estinated to be 2-5. Therefore the assumption |Ψ₈(O)|²=|Ψ₁(O)|² would lead to an overestimation for the rate of g*→QQ and it is necessary to take the suppression effect of the repulsive Coulomb force into consideration.     

The first eigenvalue of the Dirac operator on Kähler manifolds

If M^2m is a closed Kähler spin manifold of positive scalar curvature R, then each eigenvalue λ of type r (r {1, …, [(m + 1)/2]}) of the Dirac operator D satisfies the inequality λ² ≥ rR₀/4r − 2, where R₀ is the minimum of R on M^2m. Hence, if the complex dimension m is odd (even) we have the estimation

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for the first eigenvalue of D. In the paper is also considered the limiting case of the given inequalities. In the limiting case with m = 2r − 1 the manifold M^2m must be Einstein. The manifolds S², S² × S², S² × T², P³( ), F( ), P³( ) × T² and F( ³) × T², where F( ³) denotes the flag manifold and T² the 2-dimensional flat torus, are examples for which the first eigenvalue of the Dirac operator realizes the limiting case of the corresponding inequality. In general, if M^2m is an example of odd complex dimension m, then M^2m × T² is an example of even complex dimension m + 1. The limiting case is characterized by the fact that here appear eigenspinors of D² which are Kählerian twistor-spinors.     

Electromagnetically induced transparency in a Zeeman-sublevels Λ-system of cold ~(87)Rb atoms in free space

We report the experimental investigation of electromagnetically induced transparency(EIT) in a Zeeman-sublevelsΛ-type system of cold ~(87)Rb atoms in free space. We use the Zeeman substates of the hyperfine energy states 5~2S_(1/2), F = 2 and 5~2P_(3/2), F = 2 of ~(87)Rb D_2 line to form a Λ-type EIT scheme. The EIT signal is obtained by scanning the probe light over 1 MHz in 4 ms with an 80 MHz arbitrary waveform generator. More than 97% transparency and 100 k Hz EIT window are observed. This EIT scheme is suited for an application of pulsed coherent storage atom clock(Yan B, et al. 2009 Phys.Rev. A 79 063820).     

受限一维无自旋费米子系统的性质研究

本文借助于一维自旋1/2-XXZ模型的Bethe-ansatz精确解, 利用局域密度近似(LDA), 讨论了谐振势中一维无自旋费米子的密度分布, 得出了ρ-u相图(这里的ρ为无量纲的粒子数密度 变量u为相互作用强度)对相图的分析表明, 随着原子密度和近邻相互作用的变化, 系统出现五个不同的混合量子相通过对热力学硬度S_ρ的计算, 发现其可作为体系的序参量, 其奇异点可用以度量受限体系中量子相变的发生     

A reduced hamiltonian model for U(∞) gauge theories

A reduced version of the Kogut-Susskind gauge theory is presented for U(∞) gauge theories. The reduced hamiltonian , where V_ij=trU_iD_iD_jD_j(U_iD_j) ⁺ (U_iD_j)⁺, is obtained by representing the group of space translations in the diagonal part of U(∞) U(∞). The space of states is invariant to the reduced gauge transformation U_i→ωU_iD_iω⁺D_i⁺ and the scalar product carries a gauge invariant constraint on U_i The hamiltonian is also expr essed in terms of the string variables of Bars. We present the linear potential between static quarks at strong coupling and sketch the weak coupling expansion.