OPTIMAL HARVESTING POLICY FOR INSHORE-OFFSHORE FISHERY MODEL WITH IMPULSIVE DIFFUSION

This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. The complexity of this system is also analyzed. Moreover, the optimal harvesting policy are given for the inshore subpopulation, which includes the maximum sustainable yield and the corresponding harvesting effort.     

Duration-Dependent Asymmetry in Photoionization of H atoms in Few-Cycle Laser Pulses

The photoionization of H atoms irradiated by few-cycle laser pulses is studied numerically. The variations of the total ionization, the partial ionizations in opposite directions, and the corresponding asymmetry with the carrier-envelope phase in several pulse durations are obtained. We find that besides a stronger modulation on the partial ionizations, the change of pulse duration leads to a shift along carrier-envelope （CE） phase in the calculated signals. The phase shift arises from the nonlinear property of ionization and relates closely to the Coulomb attraction of the parent ion to the ionized electron. Our calculations show good agreement with the experimental observation under similar conditions.     

椭圆强非局域空间光孤子

对傍轴椭圆高斯光束在具有椭圆对称响应特性的强非局域非线性介质中的演化规律进行研究，得到了光束各参量演化的精确解析解，分析了单向空间光孤子和强非局域椭圆空间光孤子的形成条件，发现了椭圆光孤子的相移与介质响应函数的椭圆率有关. 关键词： 椭圆对称强非局域响应介质 椭圆强非局域空间光孤子 相移     

镍-酸性铬兰K络合物吸附波

用微分脉冲溶出伏安法研究了镍(11)与酸性铬兰K(ACBK)所生成的络合物在悬汞电极上的电化学特性及电化学反应机理，发现电极反应为镍与酸性铬兰K所生成的络合物吸附在电极表面后发生的不可逆还原。在HCl-硼砂介质中(pH8．67)，络合物在-316mV处有一吸附还原峰，其峰电流与镍浓度在0．001～0．010μ/mL范围内呈现良好的线性关系，其最低检出浓度为0．0005μg／mL。     

短脉冲激光辐照下金属镜面波纹损伤机理研究

用脉冲Nd：YAG激光(波长1．06μm、半高宽10ns)辐照了多种金属膜层镜面，用光学与原子力显微镜观察到某些样品损伤区或周围有规律的波纹图案，波纹周期从几微米到几十微米。通过分析实验结果，这里提出了波纹产生的光学模型，认为光路系统中某些元件的衍射或者强光与元件表面相互作用过程中产生的干涉可能会导致元件表面波纹状损伤图案。通过理论计算，初步解释了实验中波纹的周期和其他现象。     

小型高压冷阴极触发管性能分析

触发管作为一种高压开关，基于其导通时间短，可承受数千安培脉冲电流等特点被广泛应用于触发器、快脉冲产生器及大电流脉冲发生器中。随着系统精良小型化的发展需求，相应对触发管导通时间、脉冲电流和导通时间晃动等参数也提出了更高的要求。     

超宽带脉冲渐变式同轴到平板过渡结构研究

由于纳秒级的脉冲信号在平板结构传输中，辐射损较大，因此对于瞬态脉冲信号的传输一般采用同轴结构。超宽带脉冲信号的辐射较常采用TEM喇叭天线，由两片三角形的平面极板构成。对于应用TEM喇叭（或将其作为抛物面天线馈源）辐射高功率超宽带脉冲信号，一个重要的问题是如何将高功率脉冲信号由同轴传输线过渡到平板结构天线。     

Transmission Properties of THz Radiation Pulses through Very Deep Zero-Order Metallic Gratings

Very deep zero-order metallic grating structures are processed to study the transmission properties of THz radiation pulses. The experiments have been performed with two samples. The delay of the THz pulses and the corresponding resonantly enhanced transmission spectra through the samples are observed. To explain the extraordinary transmission we have treated the samples as Fabry-Perot resonators through resonant excitation of the coupled surface plasmon polaritons filled in the cavities between the metal slats. The experimental results are in reasonable agreement with the numerical simulation. Our results show that THz-time-domain spectroscopy may be an effective technique for studying the optical properties of various THz microstructured devices.     

二次升压的重复频率脉冲电源

介绍一种采用脉冲变压器二次升压工作方式实现高电压脉冲输出的设计电路，电路的主要特点是可以对电容负载实现快速充电，通常其充电时间可控制在几百纳秒内。由于在电路中的开关器件为氢闸流管和磁压缩装置，因此系统具有千赫兹的连续重复频率工作能力。目前，以这种方式工作的重复频率脉冲电源系统，脉冲调制过程的能量传输效率大于70％，输出脉冲电压大于600kV，连续重复频率大于100Hz.