大白鼠抑郁症模型的MRI方法研究

用核磁共振成象方法研究对比了抑郁症大白鼠与对照组正常大白鼠脑部的核磁共振信号强度的差别.从大白鼠大脑的核磁共振图象出发,经过数据分析,发现抑郁症大白鼠多个脑组织的核磁共振信号相对强度普遍比正常大白鼠高.另外,模型组大白鼠大脑的脑裂比对照组大白鼠的脑裂更深且更宽.     

注入控制铜蒸气激光方向性时间过程测量

实验研究了注入控制对铜蒸气激光非稳腔输出光束质量的影响，从输出光发散角时间分辨过程的测量结果说明注入加速被注入腔内激光发散角的减小过程。由于被注入腔内放大自发辐射的存在，为得到较好的注入控制效果，注入光的脉宽和进入被注入腔的延时必须恰当。     

HIRFL 束流相位测量系统性能的改进

 在研究HIRFL 相位测量系统工作原理的基础上, 用自行设计的电缆电子学长度校正方法校正了探针电缆的长度, 并重新设计了信号预选器和系统控制软件; 利用自行设计的自检系统找出并校正了影响系统测量精度的因素。提高了系统的可靠性和测量精度, 使系统可以投入实际的调束运行。     

宏观速度对电弧螺旋不稳定性影响的数值分析

采用抛物型电导率和与时间有关的线性微扰理论,给出了有宏观速度存在的热势分布(温度分布)、稳定性条件以及不稳定性增长率等定量结果。     

Submillimeter Laser Interferometer-Polarimeter for Plasma Diagnostics

The testing results of a homodyne 0.195-mm laser interferometer-polarimeter based on quasioptical components are presented. The interferometer-polarimeter matched to the multichannel interferometer of a Tokamak-15 machine admits of simultaneous measurements of the plasma electron density and poloidal magnetic field in one of the seven vertical-probing channels without any disturbance in the others. The achieved responce threshold of the electron density is 3.4·10¹¹ cm^–3, the polarization resolution and the phase difference measurement error are no worse than 0,1⁰ and ±4⁰, respectively.     

Method for Measurement of Static Parameters of Axially Symmetric Beams in Devices of Millimeter Wave Band

The new method for metering of the static parameters of the axially symmetric electron beams in the devices of the extremely high frequency (EHF) range is proposed in the paper. The method is based on using properties of the transition radiation of the optical range. The transition radiation appears when bombarding a metallic target electrode with electrons. Results of the meterings on distribution of current beam density by way of this method are given. The results are compared with the trajectory analysis when moving the electrons in the field of the investigated electron-optical system.     

时频分布后置积累法检测和识别分布目标

由于线性调频信号(LFM)的线性时频调制规律,即其模糊度和Wigner-Ville分布(WVD)图象均具有线性峰脊特性,本文利用LFM信号的这一特性,用对其回波的互模糊度函数和WVD进行分析,着重讨论沿着斜脊方向进行后置积累的检测和识别多目标回波的性能,指出WVD后置积累的检测和分辨性能比通用匹配滤波器优越。     

近程声呐亮点回波的识别与跟踪

根据目标近距离水下航行时的亮点动态分布规律,提出用两级聚类分析和边缘特征提取的图象识别方法,从声呐回波动态历程图象中识别和跟踪目标回波,并从目标动态回波图象的多个亮点中,提取和跟踪了指挥塔亮点轨迹.     

Relaxation Oscillation Enhancement and Coherence Collapse in Semiconductor Lasers with Optical Feedback

The dynamic characteristics of a semiconductor laser with optical feedback are strongly dependent on the injection current and the reflectivity and position of the external feedback reflector. We investigated the relaxation oscillation enhancement and coherence collapse state of the laser oscillation based on the laser rate equations. It is well known that laser output power jumps with increase of the injection current due to external mode transition. But here for the first we time demonstrate the existence of a chaotic scenario within successive laser power jumps. The results calculated by numerical simulations based on the rate equations are compared with those of the experiments and good coincidence between them is found.     

Decay Time of 2.09 eV Luminescence of S2--Vacancy Centers and Their Optical and Thermal Stability in NaCl:S2 Crystals

An investigation was carried out on decay time of the 2.09 eV emission of S²–vacancy pair centers in NaCl crystals. When the crystal was excited by a pulsed 337 nm light from an N₂ laser, the 2.09 eV yellow luminescence principally decayed with the lifetime of 14.2 μs at low temperatures, and exhibited a weak thermal quenching with an activation energy of 51.3 meV above about 150 K. Such S^2--vacancy pair centers responsible for the 2.09 eV luminescence were thermally stable at room temperature, and not bleached even when exposed to ultraviolet lights below about 5 eV. Thus, the 2.09 eV emission center possibly can be used as a solid-state laser active center working at room temperature.