q-畸变振子系统的解和q-振子代数

本文讨论q-畸变振子系统的解和q-振子代数及其表示的问题,并对|q|=1的情形进行详细的研究。给出SU_q(2)及q-振子代数(记为H_q(4)之间的联系。给出单q-振子系统的解,并指出它与普通仲费密振子之间的类似行为,对行为类似于1,2,3阶仲费密子的q-振子系统进行了尤为详细的讨论。最后,研究H_q(4)的表示及其性质,并简单地讨论q-畸变振子的链模型的解。     

Explicit Relations of Physical Potentials Through Generalized Hypervirial and Kramers' Recurrence Relations

Based on a Hamiltonian identity,we study one-dimensional generalized hypervirial theorem,Blanchardlike(non-diagonal case) and Kramers'(diagonal case) recurrence relations for arbitrary x~κ which is independent of the central potential V(x).Some significant results in diagonal case are obtained for special κ in x~κ(κ≥ 2).In particular,we find the orthogonal relation(n_1|n_2) = δ_(n_1n_2)(κ = 0),(n_1|V'(x)\n_2) =(E_(n_1)-E_(n_2))~2〈n_1x|n_2)(κ = 1),E_n =(n/V'(x)x/2|n) +(n|V(x)|n)(κ = 2) and-4E_n(n|x|n) +(n|V'(x)x~2\n〉 +4〈n|V(x)x|n〉 = 0(κ = 3).The latter two formulas can be used directly to calculate the energy levels.We present useful explicit relations for some well known physical potentials without requiring the energy spectra of quantum system.     

Investigation of the HFS in the 4d 5p zP3,4 states of Mo and Mo by levelcrossing spectroscopy

The hyperfine structures of the z⁷P₃ and z⁷P₄ states of ⁹⁵Mo and ⁹⁷Mo have been investigated by levelcrossing spectroscopy. A fit of the experimental signal curves yields the magnetic and electric hfs coupling constants: ⁹⁵Mo z⁷P₃ |A| = 86.19(10) MHz, |B|=5.2(30) MHz, A/B0⁹⁵Mo z⁷P₄ |A|=64.05(30) MHz, |B|=4.3(30) MHz, A/B<0; ⁹⁷Mo z⁷P₃|A|= 88.0(1) MHz, |B|=60.0(20) MHz, A/B<0; ⁹⁷Mo z⁷P₄ |A|=65.4(3) MHz, |B|=50.0(50) MHz, A/B0. For the ratio of the electric quadrupole moments we fine ⁹⁷Q/⁹⁵ Q= -11.5(70).     

The angular intensity correlation functions C(1) and C(10) for the scattering of light from randomly rough dielectric and metal surfaces

We study the statistical properties of the scattering matrix S(q|k) for the problem of the scattering of light of frequency ω from a randomly rough one-dimensional surface, defined by the equation x₃=ζ(x₁), where the surface profile function ζ(x₁) constitutes a zero-mean, stationary, Gaussian random process. This is done by studying the effects of S(q|k) on the angular intensity correlation function C(q,k|q',k')=〈I(q|k)I(q'|k')〉-〈I(q|k)〉〈I(q'|k')〉, where the intensity I(q|k) is defined in terms of S(q|k) by I(q|k)=L^-1₁(ω/c)|S(q|k)|², with L₁ the length of the x₁ axis covered by the random surface. We focus our attention on the C⁽¹⁾ and C⁽¹⁰⁾ correlation functions, which are the contributions to C(q,k|q',k') proportional to δ(q-k-q'+k') and δ(q-k+q'-k'), respectively. The existence of both of these correlation functions is consistent with the amplitude of the scattered field obeying complex Gaussian statistics in the limit of a long surface and in the presence of weak surface roughness. We show that the deviation of the statistics of the scattering matrix from complex circular Gaussian statistics and the C⁽¹⁰⁾ correlation function are determined by exactly the same statistical moment of S(q|k). As the random surface becomes rougher, the amplitude of the scattered field no longer obeys complex Gaussian statistics but obeys complex circular Gaussian statistics instead. In this case the C⁽¹⁰⁾ correlation function should therefore vanish. This result is confirmed by numerical simulation calculations.     

Pressure-Dependent Base-Wavefunction Admixture and Lifetime of R1 State of La3Lu2Ga3O12:Cr3+

As a key factor leading to the pressure-dependent R₁-line-shift reversal and R₁-state lifetime, at 10 K, the pressure-dependent variation of mixing-degree of |t₂²(³T₁)e⁴T₂〉 and |t₂³² E〉base-wavefunctions in the wavefunction of R₁ state of LLGG:Cr³⁺ has been calculated and analyzed. From this, the physical origin of the pressure-dependent R₁-line-shift reversal has been revealed. Furthermore, by using the pressure-dependent values of the sum of all square mixing-coefficients of |t₂²(³T₁)e⁴T₂〉in the wavefunction of R₁ state, the lifetimes of R₁ state of LLGG:Cr³⁺ at various pressures have been calculated, which are in good agreement with observed results. The quantum anticrossing effect between t₂³²E and t₂²(³T₁)e⁴T₂ levels due to both spin-orbital interaction and electron-phonon interaction is remarkable, which is related to the admixture of |t₂²(³T₁)e⁴T₂〉and |t₂³² E〉as well as the low-high crystal-field transition.     

Analytic expression for the electric potential in the plasma sheath

An expression for the spatial dependence of the electric potential in a collisionless and source-free planar plasma sheath is presented. This expression is derived by analogy with Child's law and approaches Child's law asymptotically as the potential drop φ_W across the sheath becomes large, |eφ_W/kT_e|>10⁴. Here k is Boltzmann's constant, T_e is the electron temperature, and e is the electronic charge. Comparison with numerical solutions of the model equations indicates that the sheath thickness and potential variation predicted by this improved Child's law are accurate for |eφ_W/kT_e|>10. In contrast, the authors find that Child's law is accurate only when |e φ_W/kT_e|>10⁴     

反向衬底偏压下纳米N沟道金属氧化物半导体场效应晶体管中栅调制界面产生电流特性研究

研究了反向衬底偏压V_B下纳米N沟道金属氧化物半导体场效应晶体管中栅调制界面产生(GMG)电流I_GMG特性, 发现I_GMG曲线的上升沿与下降沿随着|V_B|的增大向右漂移. 基于实验和理论模型分析, 得出了V_B与这种漂移之间的物理作用机制, 漂移现象的产生归因于衬底偏压V_B 调节了表面电势φ_s在栅电压V_G 中的占有比重: |V_B|增大时相同V_G下φ_s会变小, φ_s 的变化继而引发上升沿产生率因子g_r减小以及下降沿产生率因子g_f增大. 进一步发现I_GMG 上升沿与下降沿的最大跨导G_MR, G_MF 在对数坐标系下与V_B成线性关系, 并且随着|V_B|增加而增大. 由于漏电压V_D在I_GMG 上升沿与下降沿中的作用不同, 三种V_D下G_MR-V_B曲线重合而G_MF-V_B曲线则产生差异. 增大V_D 会增强g_f 随V_G的变化, 因此使得给定V_B 下的G_MF变大. 同时这却导致了更大V_D下G_MF-V_B 曲线变化的趋势减缓, 随着V_D从0.2 V变为0.6 V, 曲线的斜率s从0.09减小到0.03. 关键词： 产生电流 表面势 衬底偏压 N沟道金属氧化物半导体场效应晶体管     

Perfect Single Qubit Mirroring Effects on Two and Three Maximally Entangled Qubits

Perfect quantum state mirroring in a chain of N spins is defined as the condition in which the state |iof the chain is swapped into the state |N-i within a time evolution interval τ.Such a phenomenon is an interesting way of transfering entanglement.An expressions for the perfect mirroring of a single qubit contained in a spin chain were proposed in the past.We exploit such an expressions for calculating the evolution times in chains of both two and three spins.In the case of a chain of two qubits,we derive conditions under which the associated four Bell states diagonalize the Hamiltonian.It is found that for the two Bell states |Φ+and|Φ-,perfect mirroring does not occur(i.e.entanglement is not preserved under swapping).On the other hand,perfect single qubit mirror effect(entanglement preservation) indeed occurs for the other two Bell states |Ψ+and|Ψ- which are mapped into |Φ+and|Φ-respectively.For the case of a chain of three qubits,the effects of a perfect single qubit mirroring on a set of four maximally entangled three qubit states ψ1,ψ2,χ1,and χ2 are studied.Due to the fact that quantum mirroring preserves maximal entanglement,the states ψ1 and ψ2 are not altered.However,quantum mirroring changes the states χ1 and χ2 only if we apply perfect quantum state mirroring in the site a=1 of the three qubits spin chain.The above constrains the preservation of maximal entanglement under qubit mirroring of such a state.Due to the fact that swapping has already been experimentally tested,a posible experimental implementations of single qubit mirroring is possible.     

Four-Particle Entangled State Representation and Its Squeezing Transformation

The four-particle EPR entangled state | p,χ₂,χ₃,χ₄〉is constructed. The corresponding quantum mechanical operator with respect to the classical transformation p→e^λ₁p, χ₂→ e^λ₂χ₂, χ₃→e^λ₃χ₃, and χ₄→e^λ₄χ₄ in the state |p,χ₂ ,χ₃ ,χ₄〉is investigated, and the four-mode realization of the SU(1,1) Lie algebra as well as the corresponding squeezing operators are presented.     

线性与非线性传热过程的Curzon-Ahlborn热机在任意功率时的效率

热机性能的优化是热力学领域的一个重要问题,而工质与热源之间的传热过程是热机工作时产生不可逆的主要来源.本文在引入功率增益和效率增益两个重要参数的基础上,基于一个简化的Curzon-Ahlborn热机模型并利用合比分比原理,给出了线性与非线性传热过程的热机在任意功率输出时的效率表达式,结合数值计算详细讨论了热机在任意功率输出时的特性.研究表明,参数ξ作为功率增益δP的函数存在两个分支:在第一分支上(不利情形),效率呈现出单调变化特征;在第二分支上(有利情形),效率随着的δP变化是非单调的且有最大值.随着传热指数的增加,热机的工作区域减小,这源于非线性传热过程包含热辐射所致.进一步发现功率-效率关系曲线存在权衡工作点,热机在该点附近工作能够实现最有效的热功转换.研究结果有助于深入理解具有不同传热过程热机的优化执行.     

Glueball-Quarkonia Content of the f0(1370),f0(1500) and f0(1710)

Based on a 3 × 3 mass matrix describing the mixing of the scalar states f₀(1370),f₀(1500) and f₀(1710), the hadronic decays of the three states are investigated. Taking into account the two possible assumptions concerning the mass level order of the bare states |N> =|μμ+dd>/ √2 |S>= |ss> and |G> = |gg> in the scalar sector, M_G > M_S > M_N and M_G > M_N > M_S, the glueball-quarkonia content of the three states is obtained by solving the nonlinear equations. Some predictions about the hadronic and two-photon decays of the three states in two cases are presented. It is pointed out that the predictions about the two-photon decay width ratios for the three states can provide a stringent consistency check of the two assumptions.     

羧酸型聚芴/二氧化钛杂化材料的制备及其荧光猝灭行为

通过Suzuki偶合反应合成了聚[9,9-二辛基芴-9,9-双(丙酸基)芴](PF8COOH),并采用溶胶-凝胶法制备了羧酸型聚芴/二氧化钛(TiO₂)杂化材料。通过核磁共振氢谱(¹H NMR)、凝胶渗透色谱(GPC)、紫外-可见吸收光谱(UV-Vis)、X射线衍射(XRD)和荧光发射光谱对聚合物及其杂化材料进行了表征,并研究了杂化材料的荧光猝灭行为。结果表明,所合成的PF8COOH数均分子量为19 600,PF8COOH的紫外-可见吸收和荧光发射光谱较聚(9,9-二辛基芴)(PF8)均发生红移。通过溶胶-凝胶法制得了PF8COOH/TiO₂杂化材料,其中TiO₂主要为金红石型。杂化材料出现明显的荧光猝灭现象,TiO₂含量越大则杂化材料的荧光猝灭现象越明显。羧基的引入可使聚芴与TiO₂之间的相互作用增强,电子更容易从聚芴向TiO₂转移,因而PF8COOH/TiO₂杂化材料的荧光猝灭现象比PF8/TiO₂杂化材料更明显。     

Ultralow detection limit of giant magnetoresistance biosensor using Fe_3O_4–graphene composite nanoparticle label

A special Fe_3O_4nanoparticles–graphene(Fe_3O_4–GN) composite as a magnetic label was employed for biodetection using giant magnetoresistance(GMR) sensors with a Wheatstone bridge. The Fe_3O_4–GN composite exhibits a strong ferromagnetic behavior with the saturation magnetization M_S of approximately 48 emu/g, coercivity H_C of 200 Oe, and remanence M_r of 8.3 emu/g, leading to a large magnetic fringing field. However, the Fe_3O_4 nanoparticles do not aggregate together, which can be attributed to the pinning and separating effects of graphene sheet to the magnetic particles. The Fe_3O_4–GN composite is especially suitable for biodetection as a promising magnetic label since it combines two advantages of large fringing field and no aggregation. As a result, the concentration x dependence of voltage difference |?V| between detecting and reference sensors undergoes the relationship of |?V| = 240.5 lgx + 515.2 with an ultralow detection limit of 10 ng/mL(very close to the calculated limit of 7 ng/mL) and a wide detection range of 4 orders.     

Cosmological bounds on Dirac-Majorana neutrinos

We examine, by way of a detailed numerical calculation, the consequences for primordial nucleosynthesis of a weakly interacting neutrino which possesses both Dirac and Majorana mass terms. In the special limiting case of a pseudo-Dirac neutrino we place bounds on the pseudo-Dirac mass splitting δm_p-D. This bound is relevant to a class of models constructed to incorporate the proposed 17 keV neutrino. We find that in the standard model |δm_p-D|<10⁻¹⁰ eV. In the models with majorons the bound is less restrictive, but still several orders of magnitude more stringent than previous estimates.     

一种qk=1畸变振子及其非玻色激发

本文讨论一种q畸变振子系统在畸变参数q为实数或k次单位根时的SU_q(2)及SU_q(1,1)对称性,并指出当k为不同值时,q畸变振子具有非玻色型激发,特别地,当k=4和6时,q振子的激发是费密型的和2阶仲费密型的,本文指出文献[6]中的部分结论是平庸的。 关键词：     

挠曲电效应对向列相液晶盒响应时间的影响

应用液晶动力学理论和差分迭代方法,考虑上液晶挠曲电特性情形下研究强锚泊混合排列向列相液晶盒撤掉电压时的动态响应过程,数值计算得到液晶盒透过率随时间的变化.结果表明:随展曲和弯曲挠曲电系数和的绝对值|e₁₁+e₃₃|的增加,液晶盒的响应时间逐渐减小,当|e₁₁+e₃₃|=50 pC·m^-1时,响应时间与忽略挠曲电效应的情况相比缩短了一半.     

An analysis of the folded waveguide: a compact waveguide launcherfor ICRF heating

Theoretical and experimental investigations of the folded waveguide launcher as proposed for use in the ion-cyclotron range of frequencies (ICRF) heating of tokamak plasmas are presented. Theoretical results include an analysis of the folded waveguide using Ritz's method to obtain various field quantities. The cutoff wavenumbers from this analysis are within 10% of those calculated using an unfolded equivalent rectangular waveguide model. Measurements of cavity resonances for a scale-model ICRF-folded waveguide with a cutoff frequency of 2.4 GHz also agree closely with those calculated using an unfolded equivalent model. An unfolded equivalent waveguide model is used to evaluate the properties of an inductive strip placed in the folded waveguide. Applying variational analyses provides upper and lower bounds to the reflection magnitude |S₁₁| that are in good agreement with measured values. Polarizing plates (which have been proposed to increase the on-axis directivity of the radiated power) are modeled using an unfolded equivalent waveguide. A variational analysis is used to determine an upper-bound value of |S₁₁| in air due to a polarizing plate inside a matched folded waveguide. Measured values are found to be within 3% of the calculated values, with |S₁₁|>0.95 for frequencies between 2.5 and 4.5 GHz     

General Solution and Localized COherent Soliton Structures of the （2＋1）—Dimensional Generalized Davey—Stewarson Equations

In this paper,the variable separation approach is used to obtain localized coherent structures of the (2 1)-dimensional generalized Davey-Stewarson equations:iqt 1/2(qxx=qyy) (R S)q=0,Rx=-σ/2|q|y^2,Sy=-σ/2|q|2/x.Applying a special Baecklund transformation and introducing arbitrary functions of the seed solutions.and abundance of the localized structures of this model is derived,By selceting the arbitrary functions appropriately,some special types of localized excitations such as dromions,dromion lattice,breathers,and instantons are constructed.     

Energy Spectra of the Tunable Laser Crystal Gd3Ga5O12:Cr3+ and Their Pressure-Induced Shifts

By means of both the theory for pressure-induced shifts (PS) of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction (EPI), at 300 K, the `pure electronic' contributions and the contributions from EPI to R₁ line, R₂ line, and U band of GGG:Cr³⁺ as well as their PS have been calculated, respectively. The total calculated results are in good agreement with all the experimental data. Their physical origins have been explained. It is found that the mixing-degree of |t₂²(³T₁)e ⁴T₂> and |t₂³²E> base-wavefunctions in the wavefunctions of R₁ level of GGG:Cr³⁺ is considerable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role for PS of R₁ line or R₂ line. At 300 K, both the temperature-independent contribution to R₁ line (or R₂ line or U band) from EPI and the temperature-dependent one are important. The remarkable difference between pressure-dependent behaviors of PS of R₁ lines of GGG:Cr³⁺ and GSGG:Cr³⁺ results from the differences of their microscopic properties. The features of emission spectra of GGG:Cr³⁺ at various pressures have satisfactorily been explained.