The bell inequalities

It is shown that the Bell inequalities are conditions that must be satisfied by the probability functions of certain three-variable systems if they are to be expressible in terms of a single, nonnegative function. The generalized Bell inequalities, or CHSH inequalities, play a similar role for four-variable systems. The physical significance of the results is discussed.     

Fock space formulation of gauge invariant interacting field theories of open and closed strings

We derive the conditions that must be satisfied by three string vertex operators, in order to have a gauge invariant Chern-Simons type action as proposed by Witten for the open bosonic string, in a Fock space formulation. Given a vertex which satisfies these conditions for the open string, we show how to construct an invariant action for the closed string.     

New Bell-type inequalities forN > 4 necessary for existence of a hidden variable

The purpose of this paper is to extend Bell's inequalities to obtain some general necessary conditions for the existence of a joint probability distribution for any finite collection of Bell-type random variables. Our results show that forN > 4 many new elementary inequalities beyond those of Bell must be satisfied by any hidden variable theory.     

Astigmatism free holographic lens elements

By applying the s and t formula for a hologram lens on a curved surface the conditions which must be satisfied for astigmatism free imagery are derived. It is shown that for hologram lenses formed on surfaces which are conic sections or on a plane surface, astigmatism free imagery can be obtained for extended objects.     

关于Chew-Low理论

这篇短文讨论了Chew-Low方程的二个问题。第一,我们将它与寻常的散射形式理论作一比较,证明了二个理论的波函数除去一个常数倍外,完全相同。这个常数倍即是物理核子及裸核子的波函数的内乘积。第二,我们讨论了一般的含有二个h函数的Chew-Low方程的解,方程的形式使它们在实轴上在(1,∞)及(-1,-∞)二段上不连续。我们证明了为使解存在,交叉对称必须满足某些条件,而即使这些条件已满足,在某些情形下解的存在要求原来的h的方程含有无穷多个代表中间分立态的项。     

A micro Z-pinch as a spark of an axial detonation

Summary In order that a Z-pinch in a DT plasma could spark off an axial nuclear detonation wave severe conditions on space and time concentration of electromagnetic energy must be satisfied. Such energy compression could be achieved by a magnetic-field compressor (MFC) in which a fast liner compresses an azimuthal field (B _φ) of a micro Z-pinch. The driver of the MFC could be either a heavy-ion beam or an explosive magnetic-field generator (EMG) destroyed at each shot. In conclusion, some of the major problems associated with this approach to ICF are outlined.     

Resonance and non-recurrent rotationally ordered configuration in Frenkel-Kontorova models

We demonstrate, with a class of exactly solvable Frenkel-Kontorova models, the emergence of the non-recurrent rotationally ordered configurations whenever certain resonance conditions are satisfied among the openings in the hull function in both the commensurate and the incommensurate cases. If one insists on depicting them with hull functions, suitably defined extended numbers must be employed. The defect-mediated transition in the incommensurate case is also discussed. Received 14 October 1998     

导热几何形状反演的变分原理及边界条件的确立

本文采用变域变分原理,建立了导热几何形状反演问题的变分原理,同时获得了该问题所需满足的边界条件和附加条件.该变分原理能将未知形状的几何变量及控制方程结合在一个变分泛函中,使得数学描述简洁、紧凑,且几何变量及控制方程的求解能耦合地进行.介绍了运用该变分原理并结合有限元方法进行数值计算的方法. 关键词： 几何形状反演 变分原理 有限元 导热     

关于二维二元替换式系统相图的极值等浓度点的几点讨论

本文从二维二元替换式Collins模型系统的两相平衡曲线方程出发,求得了形成极小等浓度点或极大等浓度点类型相图原子间相互作用势所必须满足的条件,证明了极值等浓度点的唯一性。计算结果还表明,4-原子所占百分数对极值等浓度点的位置有显著影响。 关键词：     

数字无透镜傅里叶变换全息术中非傍轴及离焦像差的校正

对数字无透镜傅里叶变换全息图直接采用逆傅里叶变换进行物场的数值重建时.需要满足两个条件:第一,全息图的记录过程必须满足傍轴近似条件,否则再现过程中会产生非傍轴像差;第二,记录全息图时物平面与参考点光源到全息图记录平面的距离必须相等,否则再现过程中会产生离焦像差.理论分析了非傍轴及离焦记录条件下数字无透镜傅里叶变换全息图的灰度分布特点,并提出了相应的非傍轴及离焦像差的数值校正方法.根据实际的非傍轴或离焦记录情况.分别给所记录的数字全息图灰度分布矩阵乘以适当的非傍轴或离焦校正因子,以消除灰度矩阵中非傍轴或离焦因素的影响.然后再对校正后的伞息图灰度矩阵做逆傅里叶变换处理.即可得到准确的数字再现像.实验结果表明.该数值重建方法能够有效地消除无透镜傅里叶变换全息术中数字再现像的非傍轴像差及离焦像差,提高再现像的质量.     

Joint transmitter adaptation and power control for cognitive radio networks with target SIR requirements

In this paper we study joint transmitter adaptation and power control in the uplink of Cognitive Radio (CR) networks with target values imposed on the signal-to-interference +noise-ratios (SINR) at the CR receiver. We use a framework based on block transmissions and linear precoders to formulate this as a constrained optimization problem for which we discuss the conditions that must be satisfied by the optimal solution. We also present an algorithm which adapts the transmit precoder and power values incrementally until a fixed point is reached where the specified target SINRs are achieved with minimum transmitted power. Convergence of the proposed algorithm is discussed and is illustrated with numerical examples obtained from simulations.     

单模光纤与Ti:LiNbO3单模平面光波导端面激励耦合的研究

本文报导一个单模光纤与单模Ti扩散LiNbO3光波导的端面耦合及固定连接实验研究.利用电弧烧熔法在单模光纤端面上制成了微透镜,改善了模场匹配程度,采用二维硅V形糟,提高了光纤与波导的对准精度。     

Nonlinear response to external magnetic fields

The purpose of this paper is to study conditions under which a system of itinerate spin-$\text{1}\text{2}$ fermions might exhibit a macroscopic linear response to external magnetic fields after long times. Exact expressions are obtained for the nonlinear response of the magnetization and the total energy. We find that for a constant field there is no response (our model contains no mechanism for the relaxation of spins). For an oscillatory field there is a response in which secular terms (in the time) appear which are associated both with nonlinear terms in the external field and with contributions from the background medium. The secular terms involving the magnetic field would not be seen if one used the usual approximations of microscopic linear response theory. They give rise to new conditions which must be satisfied if the system is to exhibit a macroscopic linear response in the long-time limit.     

Complete sets of symmetry operators containing a second-order operator and the problem of separation of variables in the wave equation

For the wave equation in Minkowski space, a space is defined of nontrivial local second-order differential symmetry operators. The algebraic conditions, which, in accordance with the general theorems on the separation of variables, must be satisfied by the commutative subalgebras, including two first-order operators and second-order operator, are formulated in coordinate-free form. On the basis of these subalgebras, there are obtained all the complete sets of symmetry operators of types (2.0), (2.1). Sets are presented which do not have analogues in papers of other authors.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 115–119, April, 1991.     

The effective Hamiltonian approach for the two-nucleon distribution function

The microscopic two-body effective Hamiltonian equation satisfied by the two-nucleon distribution function needed for two-particle transfer processes is derived. The usual approximations made in order to obtain a partial solution to this equation are discussed and compared. It is concluded that contributions to the distribution function from both core state and channel coupling terms are likely to be comparable to continuum configurations in importance. Such contributions must certainly be included if an unambiguous normalization for the distribution function is desired.     

不同规范下横场与纵场的特性分析

文章按照矢量场分解为横场和纵场的方法,采用亥姆霍兹定理,研究电磁场的性质与结构.对不同规范下电磁场的横场和纵场特性进行分析与比较,讨论电磁场与源之间的对应关系.结果表明,电磁场问题由电荷场和电磁波动场两个相互独立的问题组成,远区辐射场由横场部分决定,纵场部分并不辐射出去;电磁势函数存在过多自由度可以归因于纵场分量的不唯一性,标量势所满足的方程并不独立于各自对应的矢量势所满足的方程.     

The human autodiagnostic system (Rexed's laminae as diagnostic neuroprocessors)

A position is formulated according to which the therapeutic effect of a puncture action is a result of the correction of defects in the human autodiagnostic system (ADS). The structure and functions of the ADS are examined from the points of view of pattern recognition, neurocomputing, and neurophysiology. The necessary conditions that the ADC must satisfy are formulated. It is shown that the theoretical conditions are satisfied by Rexed's laminae, which are a part of the central nervous system and form the grey matter of the spinal cord. The available biochemical and morphological data are utilized in an examination of the operating mechanism of Rexed's laminae as a whole (as an ADS) and each lamina individually (as neuroprocessors that perform specific functions). Potential defects in the recognition system and methods for their correction by signals produced at biological active points by EHF puncture are examined.P. N. Lebedev Physics Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 1, pp. 57–78, January, 1994.     

车号识别中的补偿光源

公路交通基础建设的不断发展和车辆管理体制的不断完善,为以视觉监控为基础的智能交通系统的实际应用打下了良好基础。在智能交通系统中,车牌自动识别系统是一个非常重要的发展方向。由于对车辆的监控是全天候的,车牌识别系统必须满足这种工作要求。在监控过程中存在自然光线不足的情况(夜晚,阴雨天等),也就是存在逆光环境中对车牌的识别问题,这样就需要补偿光源。目前大多采用大功率泛光灯作补偿光源。由于泛光灯自身的特点,使效果不能达到理想。文章从汽车车灯的光谱及人眼的光谱光视效率曲线等方面详细分析了逆光条件下车牌识别中补偿光源的选取。并经实验证明此选取方法具有很好的效果。     

Two-mode Gaussian states as resource of secure quantum teleportation in open systems

For secure quantum teleportation (SQT) of coherent states two conditions are necessary to be fulfilled: Gaussian-state resources with two-way steering and teleportation fidelity higher than 2/3. We investigate and compare squeezed thermal states and squeezed vacuum states as initial resource states for SQT in an open quantum system, consisting of two uncoupled harmonic oscillators interacting with a thermal environment. The evolution of the open system is obtained in terms of the covariance matrix, by using the Gorini-Kossakowski-Lindblad-Sudarshan master equation. The SQT conditions are satisfied in a longer period of time in the case of initial squeezed vacuum states, therefore these states are better resource states for SQT than squeezed thermal states. We show that the admissible time for SQT decreases by increasing temperature, dissipation coefficient and average number of thermal photons, while for greater values of the squeezing parameter, SQT conditions are satisfied in a longer period of time.     

虚边界元法与强流电子枪的电子轨迹模拟

以位势问题为分析对象,从格林公式出发严格导出了虚边界元法的基本积分方程.并以虚边界元法基本积分方程为出发点,从理论上导出了虚边界元法对虚边界形状位置的基本要求.理论结果表明,虚边界元法本身是一种严格的方法,但在一定条件下,它是一种近似方法.基于虚边界元方法开发了一套适用于强流电子枪的电子轨迹模拟程序,并对强流电子枪进行了计算.对强流电子枪的计算表明,在同等条件下,取定最佳的虚实边界距离与边界单元数,虚边界元法较边界元法的精度要高.