LD端面泵浦的1.57μm内腔式OPO

1.57 μm波长激光为人眼安全波长激光。将KTP晶体置于一个由LD端面泵浦、声光调Q的Nd:YVO4晶体双凹谐振腔内,利用KTP表面镀膜建立了内腔式OPO,实现了重复率在5～40 kHz范围内1.57 μm脉冲激光的稳定输出。实验结果表明,激光的阈值将随声光调Q器重复率的增加而升高,重复率为5 kHz时得到最低阈值1.52 W。重复率为15 kHz、泵浦功率为3.7 W时,输出光平均功率为305 mW,脉冲宽度50 ns,峰值功率400 W。     

软件测试研究

软件测试是保证软件质量和提高软件可靠性的重要手段.随着软件程序量和复杂度不断地增加,人们对软件质量的要求也在不断提高,软件测试在软件开发过程中占据的位置也变的越来越重要了,同时软件测试的工作量也显得越加艰巨.系统介绍了软件测试的概述包括软件测试的定义、阶段、过程模型和目的,并分析总结了软件测试的策略、方法和自动化.     

运动估计算法预测搜索起始点

高精度的预测搜索起始点方法可以减少运动估计算法的搜索点数,提高搜索速度和精度.对中值,均值,左块,SAD比较等方法进行了理论介绍和实验分析,提出一种新的预测搜索起始点方法.该方法足利用相邻块运动矢量的相关性和运动矢最的偏向分布特征给相邻块分配不同的权重来预测搜索起始点.实验结果表明对不同种类的标准测试序列新方法比其它方...     

锅炉整体式高效声波吹灰器性能试验研究

声波吹灰技术是提高锅炉换热效率,保证锅炉安全运行的重要手段之一.在不同压缩空气压力和流量条件下,试验对比研究了Φ80 mm×290 mm和Φ90 mm×300 mm 2种整体式耐高温高效声波吹灰器声场特性,获得了声波频率和声压值大小,确定了吹灰器声波作用的有效范围,分析了几何特征尺寸对声波的影响.     

阴极条室性能研究的结果

本文介绍了６０ｃｍ×５０ｃｍ阴极条室的设计，研制和性能研究的结果。实验测量得到的空间分辨σ≌５０μｍ，实验证明了阴极条室具有良好的性能，使其有着很好的应用前景。     

Effects of language intervention on syntactic skill levels in preschoolers.

Questions concerning the role of input in the growth of syntactic skills have generated substantial debate within psychology and linguistics. The authors address these questions by investigating the effects of experimentally manipulated input on children's skill with the passive voice. The study involved 72 four-year-olds who listened to stories containing either a high proportion of passive voice sentences or a high proportion of active voice sentences. Following 10 story sessions, children's production and comprehension of passives were assessed. Intervention type affected performance--children who heard stories with passive sentences produced more passive constructions (and with fewer mistakes) and showed higher comprehension scores than children who heard stories with active sentences. Theoretical implications of these results for the understanding of the nature of syntactic skills and practical implications for the development of preschool materials are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of experimentally induced affects.

This article describes the development of a Multiple Affect Adjective Check List designed to measure day to day changes in three affects: anxiety, depression, and hostility. Empirical criteria were used to select items and the scales were validated in several types of experimental situations. A stressful film resulted in significant increases in the Anxiety and Depression scales in females, but not in males. A "surprise exam" threat resulted in significant increases in all scales, but the greatest increase was on Hostility. Prior to an expected examination only the Anxiety scale was significantly elevated. All 3 scales responded significantly to an induced failure situation. Group means were stable over base-line days and high split-half reliabilities were found for all scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross‐level fragility analysis of modularized suspended buildings based on experimentally validated numerical models

Suspended buildings typically have a core as the primary and suspended floors as the secondary structures. These configurations offer visual transparency, smaller vertical components, and seismic attenuation via the primary–secondary structure interaction. Such attenuation is further enhanced by the modularization of the suspended segment which allows large drifts but prevents them from causing damage. Previously conducted shake‐table tests have confirmed these features. However, how the component performance contributes to system performance has not been quantitated. To address this gap, fragility analyses are conducted for 10‐story experimentally validated models with optimized supplemental dampers and inter‐module stiffness. Multiple limit state functions are proposed to provide a full account of damage sources. Additionally, a mapping rule from the component‐level to the system‐level limit states is developed which captures the influence of damage distribution on system‐level limit states. Results for the uncontrolled suspended building indicate that for the PGV of 0.5 m/s, the failure probabilities of the repairable and life safety limit states are 97% and 83%, respectively. These probabilities are 92% and 27% for the frame structure with viscous dampers, 58% and 5% for the passive‐controlled modularized suspended building system (MSBS), and 45% and 3% for MSBS with optimal vertical distributions of modularized secondary structure.     

基于GaAs MMIC技术的残余应力测试结构的模拟与设计

残余应力对开关梁的力学特性有着重要的影响。梁的弹性系数k由梁的形状和材料特性(杨氏模量和残余应力)来决定。应力梯度会使悬臂梁发生卷曲,对k也会产生影响。由残余应力引起的梁的长度变化量在微米级别,一般实验仪器难于测量。基于GaAs基和Si基的器件残余应力不同,相应的测试结构需重新设计。为了克服这些问题,本论文重新模拟并优化了微旋转式残余应变测试结构,尽量简化对测试仪器的要求。本文使用Intellisuite仿真软件以及Matlab软件优化,同时采用对称式的结构增加了测试精度。最后本文还给出了应力梯度的测试方法。     

实时运动检测电视图像内插方式的研究与实现

本文用二维谱分析了现制式广播电视图像的缺陷，研究了用内播法实现逐行扫描或倍行扫描，以使图像得到较大改善。对自适应内播法进行了重点分析，并用硬件实现了该内插方法，得到了较好的主观视觉效果。