A CNDO CI Study of the Electronic Spectrum of Biphenyl

A number of semi-empirical methods for approximation to full LCAO-SCF calculations have been developed in recent years. Of these, the CNDO method of Pople and coworkers limited to valence-shell electrons is of particular interest since it takes proper account of electronic repulsion and introduces the symplifying ZDO approximation into the Roothaan equations^1-6.     

Effect of Reaction Format on a McAb-Based Heterologous ELISA for the Insecticide Parathion

Abstract

Based on the selected monoclonal antibody, the effect of three reaction formats on sensitivity, specificity, and determination ability for real samples were investigated. The results showed the antibody-coated format was the optimal assay for parathion determination. The sensitivity of the assay was 3.20 ng/ml, with a detection limit of 0.40 ng/ml, and the assay time was 1.5 h. The average recoveries of parathion in river water, rice, cucumber, green soy bean, and cabbage were 98.56%, 89.46%, 99.25%, 118.57%, and 101.39%, respectively. In addition, when rice and cabbage extracts were analyzed by the assay and HPLC, the correlation was greater than 0.9.     

Evolution of spatial modulation of broadband laser pulses with different pulse durations in medium with non-instantaneous Kerr nonlinearity

We experimentally investigate the evolution of spatial modulation of broadband laser pulses with different pulse durations through a medium with non-instantaneous Kerr nonlinearity. By modifying the input laser pulse width, we observe the nonlinear growth of the spatial stripes that arise from interference with different modulation frequencies, and then obtain the gain spectra of the spatial modulation which clearly reveal the influence of relaxation effect on spatiotemporal modulation instability. We find that all gain spectra have the similar fastest growing frequency, but they have tails at higher frequency region in which the growth rate of gain is bigger for shorter pulse duration. The experimental results are confirmed by the perturbational analysis.     

Characteristics of gain spectrum of modulation instability in soft matter

We investigate the spatial modulation instability in colloidal suspension based on the nonlinear Schrödinger equation. By a standard linear stability analysis, we obtain the expression for instability gain and identified the relationship between the measurable instability characteristic parameters and the particle radius, the optical beam width. It is shown that the modulation growth rate, the maximum growth rate, cut-off frequency and the fastest growth frequency increase as the particle radius decreases and (or) the beam width increases if the optical intensity is constant. Moreover, the ultimate values of the cut-off frequency and the fastest growth frequency are proportional to the beam width, while are independent of the sphere radius. The results provide a new approach to measure the sphere radius and to control the characteristic parameters of modulation instability through the beam width.     

Optical Time-to-Three-Dimensional (3-D) Space Interconversion System

We propose a new technique for an interconversion between a three dimensional (3-D) spatial signal and a temporal signal. It is realized by combination of a holographic technique, a 2-D spatial filtering technique and a time-space conversion technique. Using this method, we can physically utilize the multiplicity between a temporal domain parameter and all of the spatial domain parameters of light. To demonstrate the proposed technique, we achieved experimentally conversion from different three point light sources as 3-D spatial signals into a temporal signal and vice versa.     

干涉成象光谱仪象移补偿研究

本文研究了遥感用干涉成象光谱仪的象移补偿问题,通过实验和理论推导得出了干涉成象光谱仪在获得空间和光谱信息两种情况下对象移量的要求,认为在使用线阵探测器时可以不采用象移补偿技术,而在使用面阵探测器时应根据逐行推扫或逐帧推扫方式来确定是否是采用家移补偿.     

An analytical study of a periodically driven laser with a saturable absorber

We consider the rate equations for a laser with an intracavity saturable absorber and subject to a periodically modulated pump. By deriving simplified equations for a map valid for strongly pulsating regimes, analytical conditions are determined that specify the properties of both frequency-locked and unlocked behaviors. As the strength of the modulation is increased, quasiperiodic and period-doubling bifurcations are predicted. However, only the transition from locking to non-locking through a quasiperiodic bifurcation is possible for realistic values of the parameters. Our results are consistent with previous numerical and experimental studies of modulated lasers with a saturable absorber. Received 10 March 2001     

Gyrotron Radiation Affected by a Controlled Modulated Reflector: High Power Experiment

An experiment performed with the gyrotrons of the TJ-II ECRH system has been performed to influence the gyrotron output radiation with a relatively weak wave returned from an external mechanically modulated reflector. An original method is proposed for directly measuring the wavelength of electromagnetic radiation in the free space. The method has been demonstrated in measurements of the wavelength of a high-power gyrotron radiation in the millimeter wavelength range used for plasma ECR heating in the TJ-II stellarator.