电场极化方向对自由空间电场测量的影响

介绍了自主研制的脉冲电场原始波形测量系统的模块组成与基本工作原理。针对在未知被测电场方向及复杂的电场环境下垂直干扰电场对自由空间电场测量产生的影响,通过建立自由空间电场测量系统前端的简化模型,对不同尺寸天线与屏蔽盒进行仿真计算。仿真计算结果与理论分析基本一致,结果表明：干扰电场响应信号与待测电场响应信号相差2个数量级以上,干扰电场的影响可忽略不计。     

BAY41-4109对乙肝病毒衣壳组装的影响

乙肝病毒衣壳蛋白成功组装成衣壳二十面体的过程是病毒前基因组RNA逆转录形成成熟DNA的必要步骤。衣壳结构的轻微改变或破坏能对病毒子代传播产生巨大影响。应用透射电子显微镜研究发现小分子抗病毒化合物（heteroaryldihvdropyrimidine,HAP）BAY41．4109在与衣壳蛋白二聚体摩尔浓度比达到1：2时,能干扰乙肝病毒衣壳蛋白组装成衣壳二十面体。在BAY41—4109的作用下,衣壳蛋白发生错误组装,形成不规则球体、平面片状结构和管状结构。应用图像处理技术对管状结构进行分析,发现它是衣壳蛋白重新装配形成的具有螺旋对称性的规则组装体,衣壳蛋白按六角晶格方式排列,其最小组成单位是衣壳蛋白的二聚体。     

太阳能手机充电器的设计

设计了基于单片机的太阳能充电器,通过脉宽调制对手机电池充电曲线进行模拟,并且用单片机对充电、放电过程进行智能控制,从而提高太阳能电池输出功率及手机电池的使用效率,达到延长电池使用寿命的目的。     

PIN调制器用于线性脉冲调制的可能性

本文分析了PIN调制器的电流调制特性,对其在线性坐标上呈现的高度非线性作了讨论,并进一步提出了采用对数网络使其线性化的电路补偿方法,这种方法在实验中已获得成功。     

高重复频率高压脉冲发生器

正 (一)引言 激光电光调制技术以及其它一些物理实验需要重复频率高、电压幅度高、宽度可变的快速高压矩形脉冲发生器。根据需要,我们设计了双臂式充放电电路。同时调试安装了两种规格的高压脉冲发生器。 采用国产FM-30束射四极管作为高压充放电管,达到的指标如下: (1)脉冲幅度:最高5kV(250V5kV连续可调,零电位为250V)。 (2)前后沿时间:负载电容为100pF时,0.5s;负载电容为200pF时,0.8s     

Magnetic Properties of Pt-Based Nanoalloys: A Critical Review

In recent years, magnetic nanoalloys (MNAs) have attracted many attentions from all over the world, due to their potential applications in the broad fields of magneto-optics, data storage, engineering, and biology. Among these MNAs, Pt–M (M = Fe, Co, Ni) MNAs have been considered to be the most promising ones, due to their superparamagnetism and response to a magnetic field. Here, we firstly review the experimental work on the synthesis, characterization, and magnetic properties of Pt–Fe, Pt–Co, and Pt–Ni MNAs. Then, we discuss the recent theoretical work on Pt–Fe, Pt–Co, and Pt–Ni MNAs. Moreover, we also review the main applications of Pt–Fe, Pt–Co, and Pt–Ni MNAs in the fields of biology, information storage, and magnetic separation. It is found that the size, shape, and composition of Pt–Fe, Pt–Co, and Pt–Ni MNAs play a critical role on their fundamental magnetic properties from both the experimental and theoretical points of view. It is expected that this review could be a valuable resource for both experimental and theoretical researchers, who are interested in Pt-based MNAs.     

Enhanced slow light propagation in photonic crystal waveguides using angular properties of scatter elements

Applicability of the angular properties of scatter elements as a tool to achieve improved slow light performance with small group velocity dispersion and large bandwidth in photonic crystal waveguides is investigated. A polyatomic photonic crystal waveguide, including two scatter elements with different geometrical shapes in each primitive cell, is proposed to investigate the feasibility of our method. Numerical results show that a versatile control of the dispersion relation of slow light modes, with large normalized delay-bandwidth products ranging from 0.2085 to 0.3394, can be obtained using a unique geometrical parameter.     

Notable shift of ultraviolet intensity on Sn-doped ZnO nanostructure fabricated by sol–gel method

Sn-doped ZnO (SZO) thin films are deposited by sol–gel dip-coating method with Sn content at 0 at.% and 1–15 at.% with an increment of 2 at.%. The structure and luminescence of the films are investigated. X-ray diffraction results indicate that all the SZO samples show preferential orientation along the (002) direction, and the scanning electron microscope exhibits that the surface morphology of the films change from nanoparticles to nanorods with increasing Sn concentration. X-ray photoelectron spectroscopy reveals that Sn exists as valence of +4 in the matrix. The photoluminescence peaks at 381 and 398 nm are observed in all the samples. The ratio of intensity of peak at 381 nm to that of peak at 398 nm differed markedly. The intensity of peak at 398 nm might be due to the response for the Sn atoms, while the intensity of peak at 381 nm is probably related to the quantum size effect.