激光二极管抽运Cr^4＋：YAG被动调Q Nd：YVO4激光器的实验研究

对激光二极管(LD)抽运的Cr^4 ：YAG被动调Q Nd：YVO4全固态激光器进行了实验研究。着重研究了抽运功率，Cr^4 ：YAG晶体的初始透过率及其在激光腔中的位置等因素对激光器输出脉冲宽度和重复频率等性能的影响，并对实验结果进行了相应的分析讨论，在理论上加以合理的解释。     

Transfer in artificial grammar learning: The role of repetition information.

In this article, the authors report 2 experiments that investigated the sources of information used in transfer and nontransfer tasks in artificial grammar learning. Multiple regression analyses indicated that 2 types of information about repeating elements were crucial for performance in both tasks: information about the repetition of adjacent elements and information about repetition of elements in the whole item. Similarity of test items to specific training items and chunk information influenced participants' judgments only in nontransfer tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Influence of Repetition and Famousness on the Intracranially Recorded Temporobasal N200.

It is still a matter of debate at which time point faces are recognized as familiar, with some studies claiming a relatively early face recognition and others later effects of familiarity. The authors report on effects of famousness of depicted persons and stimulus repetition on intracranially recorded event-related potentials. Famousness resulted in an increased latency of the N200 component, as well as in an increased amplitude of a later long-lasting potential (N700). In contrast, repetition led to an increased amplitude of the N200 but no increase of its latency. They suppose that the recognition of faces becomes observable within the N200 latency range and that the increased N200 latency reflects a feature processing additional to the holistic face processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of repetition and time pressure on effectiveness of mobile advertising messages

This study conducted two experiments to investigate the influence of advertising repetition and time pressure on mobile advertisement effectiveness. The first experiment examined the effect of advertising repetition in everyday life. SMS advertisements with different repetitions were sent to participants during 6 weeks. The results indicated that it was better to send less than three mobile advertisements each day. The second experiment examined the effect of time pressure in the lab controlled environment. Under high or low time pressure, participants received SMS advertisements while searching information through webpages. The results indicated that low time pressure contributed to better mobile advertisement effectiveness than high time pressure.     

毫米波雷达信号模拟器研制

设计了一个毫米波脉冲雷达信号模拟器。该模拟器通过模拟各种实际环境中不同重频、不同占空比、不同参数特性的雷达回波信号,检测机载电子对抗系统对雷达目标的侦测和告警能力。该模拟器发射功率大于5 W,脉冲宽度100 ns,重复频率200 Hz～400 kHz,杂波抑制优于60 dBc,功耗小于5 W,体积160 mm×150 mm×85 mm。和现有的雷达信号模拟器相比,它具有功能可扩展能力强、体积小、功耗低、重量轻、工作寿命长等优点。     

多模雷达信号重频跟踪器系统的设计

针对目前越来越多使用的多模雷达,提出一种适合跟踪多模雷达信号的重频跟踪器系统。跟踪器系统加入了跟踪雷达数据库,60通道的波门输出可以采用合成波门输出方式。跟踪器系统由数字信号处理器和现场可编程门阵列实现。     

1030nm高重复频率纳秒脉冲全光纤放大器

采用脉冲调制的单模带尾纤输出的半导体激光器作为种子源,以掺镱光纤为增益介质,采用主振荡功率放大(MOPA)结构,实现了1030nm全光纤脉冲激光放大。脉冲重复频率在50～100kHz范围内可调,在重复频率50kHz时,实现了脉冲宽度为6.53ns,峰值功率为16.08kW的脉冲输出,相应的斜率效率为69%,输出激光的中心波长在1029.49nm。实验还研究了不同重复频率下输出激光脉冲的时域特性。该激光器的输出波长在激光雷达探测器的光谱响应范围内,可作为激光雷达发射光源。     

激光能量及重复频率对土壤等离子体特性的影响

利用波长为1064 nm的Nd∶YAG脉冲激光器作光源,以高分辨率、宽光谱段的中阶梯光栅光谱仪和增强型电荷耦合器件(ICCD)作为谱线分离与探测器件,测量并分析了激光能量及重复频率对土壤中铅元素激光诱导击穿光谱特性的影响。实验结果表明,随着激光脉冲能量(在25~105 mJ范围内)增加,谱线强度呈线性增加,随后谱线强度随脉冲能量(105~165 mJ)的变化呈非线性关系。信背比随激光能量的增加而增大,但激光能量超过60 mJ后基本上不变。激光重复频率为1 Hz时,谱线强度最大,而谱线强度的相对标准偏差则在重复频率为7 Hz时最小。     

Adult Age Differences in the Implicit and Explicit Components of Top-Down Attentional Guidance During Visual Search.

Two experiments investigated adult age differences in the explicit (knowledge-based) and implicit (repetition priming) components of top-down attentional guidance during discrimination of a target singleton. Experiment 1 demonstrated an additional contribution of explicit top-down attention, relative to the implicit effect of repetition priming, which was similar in magnitude for younger and older adults. Experiment 2 examined repetition priming of target activation and distractor inhibition independently. The additional contribution of explicit top-down attention, relative to the repetition priming of distractor inhibition, was greater for older adults than for younger adults. The results suggest that some forms of top-down attentional control are preserved as a function of adult age and may operate in a compensatory manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

微机控制脉宽可调的重复频率Nd：YAG激光器

本文介绍了一种没有脉冲形成网络的新型脉冲激光电源的主回路。分析了用单板计算机控制其输出频率与脉冲宽度，脉冲波形的原理及方法，对不同脉宽和放电波形条件的输出特性进行了简要分析。该电源泵浦的激光器输出频率为５０Ｈｚ内可调，脉宽０．２ｍｓ－１０ｍｓ内连续可调。这种输出参数能满足广泛的微加工要求。