Sensing the ortho Positions in C6Cl6 and C6H4Cl2 from Cl2− Formation upon Molecular Reduction

The geometrical effect of chlorine atom positions in polyatomic molecules after capturing a low-energy electron is shown to be a prevalent mechanism yielding Cl₂⁻. In this work, we investigated hexachlorobenzene reduction in electron transfer experiments to determine the role of chlorine atom positions around the aromatic ring, and compared our results with those using ortho-, meta- and para-dichlorobenzene molecules. This was achieved by combining gas-phase experiments to determine the reaction threshold by means of mass spectrometry together with quantum chemical calculations. We also observed that Cl₂⁻ formation can only occur in 1,2-C₆H₄Cl₂, where the two closest C–Cl bonds are cleaved while the chlorine atoms are brought together within the ring framework due to excess energy dissipation. These results show that a strong coupling between electronic and C–Cl bending motion is responsible for a positional isomeric effect, where molecular recognition is a determining factor in chlorine anion formation.     

Effect of Bauhinia monandra Kurz Leaf Preparations on Embryonic Stages and Adult Snails of Biomphalaria glabrata (Say, 1818), Schistosoma mansoni Cercariae and Toxicity in Artemia salina

Biomphalaria glabrata snails constitute the main vector of schistosomiasis in Brazil, and Bauhinia monandra Kurz, the leaves of which contain BmoLL lectin with biocidal action, is a plant widely found on continents in which the disease is endemic. This work describes the composition of B. monandra preparations and the effect on embryos and adult snails, their reproduction parameters and hemocytes. We also describe the results of a comet assay after B. glabrata exposure to sublethal concentrations of the preparations. Additionally, the effects of the preparations on S. mansoni cercariae and environmental monitoring with Artemia salina are described. In the chemical evaluation, cinnamic, flavonoid and saponin derivatives were detected in the two preparations assessed, namely the saline extract and the fraction. Both preparations were toxic to embryos in the blastula, gastrula, trochophore, veliger and hippo stages (LC₅₀ of 0.042 and 0.0478; 0.0417 and 0.0419; 0.0897 and 0.1582; 0.3734 and 0.0974; 0.397 and 0.0970 mg/mL, respectively) and to adult snails (LC₅₀ of 6.6 and 0.87 mg/mL, respectively), which were reproductively affected with decreased egg deposition. In blood cell analysis, characteristic cells for apoptosis, micronucleus and binucleation were detected, while for comet analysis, different degrees of nuclear damage were detected. The fraction was able to cause total mortality of the cercariae and did not present environmental toxicity. Therefore, B. monandra preparations are promising in combating schistosomiasis since they can control both the intermediate host and eliminate the infectious agent, besides being safe to the environment.     

基于海洋背景红外图像的仿真系统研究

简要介绍了一种简便的基于海洋背景的红外仿真系统的设计和组成,阐述了各个模块的功能以及模块之间的联系。在实际存储红外图像素材基础上,通过直接添加模板图像,接着通过后续的处理模块来实现较好的模拟海洋红外图像中的目标的目的。从最后的结果可以看到这是一个简便有效的仿真系统。     

一种新型薄腔法-珀干涉测速系统研究

本文所关注的激光干涉测速技术主要用于测试在冲击波或爆轰波作用下各种材料样品的自由面速度随时间变化的过程,介绍了基于光学谐振腔的选频特性利用薄腔法-珀干涉仪直接测量高速飞片所引起的多普勒频移从而获得其速度信息的设想,并根据此设想构建薄腔法-珀干涉测速系统的技术路线。最后描述了利用该项测试技术实际测量金属箔电爆炸驱动的Kapton膜飞片速度的实验并对实验结果进行了分析。与其它激光测速装置相比,该干涉仪具有体积小、结构简单紧凑和成本低的特点。     

电控宽带连续调谐外腔半导体激光器

介绍了一种电控调谐的外腔半导体激光器，并对其连续调谐特性进行了理论和实验分析。压电陶瓷（ＰＺＴ）（双晶片）的电扫描角度可达１°，采用适当的外腔结构，靠ＰＺＴ可同时改变外腔腔长和光栅衍射角，实现输出波长的调谐。该器件调谐范围最大可达１５ｎｍ，连续调谐范围（无跳模）为５０ＧＨｚ     

掺硫NaCl晶体中（F_2~＋）_H心的形成及其稳定性

报道了掺硫ＮａＣｌ晶体（Ｆ＿２￣＋）＿Ｈ心的制备过程以及（Ｆ＿２￣＋）＿Ｈ心的室温避光稳定性。讨论了Ｓ２－对Ｆ＿２￣＋的稳定作用和（Ｐ＿２￣＋）Ｈ制备过程中的缺陷化学反应．研究表明．促使Ｆ３心热分解成Ｆ心和控制好转型光的辐照剂量是制备高浓度、高纯度（Ｆ＿２￣＋）＿Ｈ心材料的关键技术之一。     

金属网栅耦合的光泵腔式亚毫米波激光器

采用电感性金属网栅作为光学谐振腔的反射镜和反射镜和输入输出耦合器，设计制作 了长度分别为１００ｃｍ、２０ｃｍ和１０ｃｍ的Ｆａｂｒｙ－Ｐｅｒｏｔ腔式亚毫米波激光器，分别用ＴＥＡ－ＣＯ２激光器的１０Ｒ（８）线和９Ｒ（１６）线洋浦源，成功地获得光泵ＮＨ３分子亚毫米波激光，根据Ｆ－Ｐ腔的多光束干涉特性，动用量子系统的密度四理论，对上述激光器光学特性和ＮＨ３分子亚毫米波激光的频谱特性进行了理论研究。     

低波纹度快速响应压电陶瓷驱动电源的研制

压电陶瓷驱动电源是压电陶瓷微位移器应用中的关键部件。文章提出了一种新的压电陶瓷驱动电源结构,并开发研制了新的压电陶瓷驱动电源,该电源采用直接稳压和放大方式,具有输出精度高,响应速度快,波纹度小,驱动能力强,稳定性好,结构简单,调试方便,造价低廉,实用性强等特点,适用于各种电压陶瓷驱动器。     

激光斜入射条件下“猫眼”效应的实验研究

"猫眼"目标回波功率是激光主动探测系统的重要指标,可用来评估光电装备"猫眼"效应的强弱,并为探测器的优化设计提供参考。依据所建立的斜入射条件下"猫眼"目标回波功率数学模型,仿真分析了入射角对"猫眼"目标回波功率的影响,利用搭建的激光主动探测系统对典型"猫眼"目标进行了实验研究,理论仿真结果与实验结果表明,激光在有限斜入射条件下,"猫眼"目标回波功率将随入射角的增大而迅速下降,并很快湮没于噪声之中。这为进一步研究基于"猫眼"效应的激光主动探测适用条件提供必要的实验依据。     

基于预充电和双采样技术的 S/H 电荷共享消除技术

针对开关电容采样/保持(S/H)电路中由负载电容记忆效应引起的电荷共享问题进行了建模.电荷共享效应会导致运放建立幅度增加,根据所推导的运放建立总公式,得出建立幅度增加会增大对运放功耗和带宽要求,或者降低建立速度.为改善该现象,基于预充电思想和双采样技术提出了一种优化方案,能在保持原 S/H 电路速度不变时,消除电荷共享效应对运放功耗和带宽的额外要求.仿真实现的12位100Msps 双采样/保持电路证明了其有效性.