输出千瓦级基模CO_2激光的七折光学谐振腔

报道了一种成功地在横向磁场约束的直流辉光放电激励横向流动ＣＯ２激光器上输出千瓦级基模光束的七折腔的结构、参数及实验结果，并对其进行了讨论。     

一种基于LS自适应AR建模的高分辨率时间延迟估计方法

本文提出了一种基于最小二乘（ＬＳ）自适应ＡＲ建模的时延估计方法。这种方法以接收信号的功率谱密度函数为时间序列，利用最小二乘格型自适应滤波器经由ＡＲ建模而得到高分辨率的时间延迟估计。文中给出了这种方法的原理、具体实现及性能分析，并以相关时延估计方法为参照进行了计算机模拟。     

The contributions of amplitude-and phase-sensitive detection to the synchronous demodulation in a RF SQUID magnetometer

It is known that the tank-circuit voltage of the rf SQUID carries information about the magnetic flux to be detected in amplitude and phase. The coherent demodulationtechnique utilizes mixing circuits to shift the rf tank voltage spectrum to dc without loss of any signal-information both in amplitude and phase (AM & Pm-detection). Vice versa such a combined detection can be devided into two several detection channels, amplitude sensitive detection (AM) and phase sensitive detection (PM). The contribution of each single mode to the combined detection AM & PM is analysed theoretically in the limit of small magnetic signals and measured in special rf circuits of the magnetometer, which apply PLL-techniques. The influence of feedback is also calculated. For refined studies of the interesting parameters the reference signal of the rf mixer allows to be phase-shifted by an arbitrary amount. All three modes of detections are sketched in diagrams as magnetometeroutput versus phase-shift of that reference signal. In addition, noise analysis is included and measured for vanishing signal. Basic formulas are derived for signal-to-noise ratios. A correlation coefficient is defined for recording correlated noise sources between AM and PM, whereby the possibility of S/N-improvement is pointed out. By computer support the graphs of equations are fitted to measured data with least mean-square deviation. More logical than functional circuit diagrams complete the insight into the treated basic ideas.     

The BMLA/LS technique and its application in A mobile satellite communication channel

The burst mode link analyser with least squares algorithm (BMLA/LS) is a real-time impulse or frequency response extraction (IRE/FRE) technique of a satellite communication channel, originated and explored by the author. This paper summarizes some key technical points of the BMLA/LS and presents its novel simulation results and applications in a land-mobile DBPSK/DQPSK satellite channel at K_a-band, including the channel additive white Gaussian noise (AWGN) effect on IRE/FRE by BMLA/LS, and the instantaneous IRE/FRE in a Rician channel with multi-path reflection, in a shadowed channel by trees and in a combinational fading channel, and their comparisons and conclusions.     

On the theory of option pricing

The objective of this article is to provide an axiomatic framework in order to define the concept of value function for risky operations for which there is no market. There is a market for assets, whose prices are characterized as stochastic processes. The method consists of constructing a portfolio of these assets which will mimic the risks involved in the operation. We follow the terminology of the theory of options although the set-up goes beyond that particular problem.     

An error propagation in the numerical literature

An important historical paper on the numerical solution of pde's has regularly, but incorrectly, been assigned to the year 1951. The origin of this error of reference is discussed.     

The algebraic uniqueness of the addition of natural numbers

As is known, multiplication is aniteration of addition within the natural numbers. We show that addition is essentially theonly associative binary operation on natural numbers whose iteration is commutative or associative. This result, in which a set determines a structure, is in a sense a converse of the classical one due to Pontrjagin [3] and Kolmogorov [1], in which certain algebraic and topological structures determine the fields of real and complex numbers and of quaternions.     

ⅡA,ⅡB族第一激发态原子中的角动量耦合

随着主子量子数ｎ增大，ⅡＡ，ⅡＢ族第一激发态原子中价壳电子间库仑排斥作用减弱，电子自身自旋－轨道相互作用相对增强，从而导致其对ＬＳ耦合方式的逐渐偏离和ｉｊ耦合方式的逐渐介入，组态混合方法可用来定量计算ＬＳ耦合方式的偏离程度。     

Study a0(980)-f0(980)mixing in charmonium decays

In this proceeding,we propose to directly measure the a00(980)-f0(980)mixing in J/ψ→φ f0(980)φa00(980)and χc1 →π0a00(980)→π0f0(980)with the upgraded Beijing Electron Positron Collider(BEPCII)with BESⅢ detector.We show that a narrow peak of about 8 MeV will be produced by the a00(980)-f0(980)mixing,and the predominant feature makes it standing out from the background contributions.The predicted branching ratios for these two reactions are both expected to be about O(10-6),which is unambiguously accessible with109 J/ψ and 3 × 108 χc1 at BESⅢ.