LD端面泵浦高效Nd:YVO4激光器

报道了激光二极管泵浦高效Nd:YVO4固体激光器的输出功率特性的研究.在基波光输出490mW时,光-光转换效率为49%.并对实验结果进行了分析和讨论.     

家兔灌服敌杀死急性中毒试验

选用32只中国本兔进行敌杀死急性中毒试验,36只兔随机分成4组,每组8只,分别灌服104、130、162和203 mg/kg体重的敌杀死,用简化寇氏法求出家兔敌杀死的半数致死量(LD50)为133.6 mg/kg体重.     

对差生概念含义的探讨

笔者依据国内外有关资料与文献,在比较国内外学者对差生概念界定的基础上,重点分析了由于学习能力存在障碍而导致学习成绩落后的学生,即学习能力障碍儿童（Ｌｅａｒｎｉｎ Ｄｉｓａｂｉｌｉｔｉｅｓ：简称ＬＤ儿童）其含义及特征,并结合当前国内对此类儿童的研究,从教育心理学的角度探讨了研究这类差生的重要性与必要性。     

LED、LD光源在物理实验中的应用尝试

物理实验中使用的光源通常有白炽灯、纳光灯、低压汞灯和氦氖激光器等,它们统属于气体光源。近年来,LED、LD构成的半导体光源,在各个领域被广泛应用。笔者对LED、LD光源在物理实验中取代传统的气体光源进行探索和尝试,并取得有益的经验。实践证明,由于LED、LD光源构造的特殊性,实验效果往往更优于气体光源。     

Perceived self-efficacy and social anxiety changes in high school students with learning disabilities (LD) during first year of secondary vocational education

This empirical study focused on high school students with a learning disability (LD), particularly adolescents undergoing training in secondary vocational study programmes. A total of 417 1st-year high school students were included in the survey, 105 of whom were LD students. Data on social anxiety and perceived social self-efficacy were collected at the beginning and end of the school year using the Social Self-Efficacy Scale and the LSAA Social Anxiety Scale. The results mostly relate to male students because the sample included 359 boys and 58 girls. In both the initial and final measurements, a significantly lower level of perceived social self-efficacy and a higher level of social anxiety were found in students with special needs compared to their peers. Perceived self-efficacy in LD students decreased significantly during the school year, while changes in social anxiety were not statistically significant. Results could indicate some difficulties in social integration of LD youths in vocational school classes. Thus, it would be desirable for schools to provide a more supportive and efficient learning environment for strengthening social integration of LD students in secondary vocational education.     

光敏感核不育水稻花粉败育过程中花药的差示扫描量热法(DSC)研究

本文以湖北光敏核不育水稻(Hubei Photoperiod Sensitive Genio Male—Sterile Rice i·e·HPGMR)农垦58A和常规品种农垦58为材料,在人工控制的长,短日照条件下,用DuPont9900型差示扫描量热计测取了不同发育时期花药的DSC谱。结果表明:可育花药的DSC谱上的低温吸热峰面积随发育呈现周期性变化;不育花药在单核中期以前与可育花药差别不大,而在单核中期以后的DSC谱上的低温吸热峰面积明显小于可育花药,且不呈现周期性变化,而逐渐减小到接近对零。     

LD泵浦Nd:GdVO4三能级激光跃迁研究

目的研究实现LD泵浦Nd：GdVO4三能级激光跃迁的相关条件.方法实验探测分析.结果得到在不同腔损耗情况下的能级跃迁光谱.结论由于发射截面大的四能级跃迁对激光上能级粒子数损耗严重,很难形成高效的三能级激光振荡,抑制四能级跃迁是获得这些三能级激光振荡的前提条件.随着腔镜对这些三能级跃迁损耗的增加,激光发射和泵浦吸收的平衡过程将导致激光发射波长蓝移.     

一种基于语义网格的E—Learning系统框架

通过分析知识社会学习方式的特征以及建构学习环境的技术趋势,提出一种基于语义网格的E—Learning系统框架,阐述了在该框架下实现IMSLD和SCORM学习规范的模型．最后指出相关工作及进一步的研究方向．