High photosensitivity and low dark current of photoconductive semiconductor switch based on ZnO single nanobelt

Photoconductive semiconductor switch (PCSS) based on ZnO single nanobelt (NB) was fabricated by controlling the concentration of mixed solution and using the probe technique, and applied into a test circuit to control the circuit state. The current-voltage characteristics and voltage spectra were investigated by system source meter and oscillograph, and the results show that the PCSS is of high photosensitivity of ∼10⁴, low dark current of ∼10⁻³ μA, low power consumption of ∼2.45 μW, typical rise time 0.12 s, and decay time 0.15 s. Within the wavelength range of 280-340 nm, the shorter the wavelength is, the higher the voltage response is. The test circuit state conversion between “1” and “0” is obviously corresponding to UV illumination “on” and “off”. The high photosensitivity and low dark current of PCSS can be reasonably explained by using the view point of light absorption and oxygen chemisorption mechanism.     

移动无线网络智能路测的研究与应用

中国移动的通信网络覆盖日益广阔,用户数接近8亿。为了提升无线网络环境的质量,及时发现网络盲点,提高人工路测的效率,本文通过Nb/Mc接口采集得到的信令和媒体数据及手机终端进行研究分析。编写简易的手机测试软件,得到了智能路测工具及方法。结果表明,该方法能有效地缩短人工路测的时间,提高40%的工作效率。新方法的应用能够准确分析无线网络上下行的质量问题,从而解决网络建设和运维中质量、容量和覆盖等三者间的矛盾,具有较高的推广和应用价值。     

Stripping voltammetry at micro-interface arrays: A review

In this article, a comprehensive overview of the most recent developments in the field of stripping voltammetry at regular micro-interfaces (both solid–liquid and liquid–liquid interfaces) is presented. This review will report on the most conventional arrays of metallic micro-electrodes but also on the rapidly growing field of electrochemistry at arrays of micro-interfaces between two immiscible electrolyte solutions (μITIES). The main fabrication methods, together with some design considerations and diffusion phenomena at such interfaces are discussed. Main applications of micro-interface arrays are presented including heavy metals detection at micro-electrode arrays and detection of organic molecules (amino acids, vitamins, peptides and drugs) at the μITIES. Stripping analysis at micro-interface arrays is suitable for the detection of analytes in several real media including water, soil extracts and biological fluids (blood and saliva) with high specificity, sensitivity (detection limits of nM, ppb level) and reliability. Stripping analysis at μITIES and micro-electrode arrays are two complementary approaches that have the advantages of being cost effective, simple to use and easily adaptable to field measurement.     

Measurements and characterization of power transformer and low voltage access network for NB‐PLC

Several techniques for a state‐of‐the‐art advanced metering infrastructure (AMI) within the smart grid are being extensively studied and evaluated around the world. Advanced metering infrastructure provides an enhanced and efficient energy management infrastructure that can facilitate the latest demands of electric utilities, consumers, and smart grid. In the past few years, standardization process for the implementation of AMI using narrowband power line communications (NB‐PLC) transceivers has been completed by ITU‐T and IEEE. This paper is focused on the utilization of CENELEC band of NB‐PLC for deployment aspects. The power transformer model of 200 and 75 kVA transformers for 9 to 90 kHz frequency range that lies in CENELEC‐A band of NB‐PLC is also proposed. The proposed model is more simple than previously presented models in the literature and has the capability to evaluate the transformers working not only under normal condition but also under resonance condition for frequency of interest. Moreover, the efficient procedure for field measurements that provides a generalized NB‐PLC channel model for low voltage access network to deploy AMI within Lahore, Pakistan, is presented. A Simulink model is developed to validate the results. The analysis of measured and simulated results illustrates a close agreement of channel transfer functions. This research work proposes an improved and more accurate NB‐PLC channel model especially for South Asian countries.     

Synthesis and anti-tumor activity of all-trans retinoic acid derivatives

A series of retinoate and retinamide derivatives were designed,synthesized,and their anti-tumor activities were investigated in NB4 by MTT and flow cytometry assays(FCM).All compounds showed cytotoxicity,especially compounds 1a and 1d exhibited a higher cytotoxicity than other derivatives and all-trans retinoic acid(ATRA).Furthermore,compound 1d could induce NB4 cell lines differentiation efficiently.     

EAST反向束在不同电流平台下注入的实验分析

对EAST装置在相同束放电参数不同等离子体电流平台下开展的束反向注入实验进行了比较分析，并利用NUBEAM程序分析了不同的等离子体电流放电平台对束电流驱动、束功率沉积、束功率沉积分布及束能量损失的影响，以此来寻求优化的注入本底等离子体参数。结果表明，较高的电流平台更有利于束与等离子体的作用以及更有效提高本底等离子体温度、束驱动电流及等离子体旋转，更有效改善等离子体约束品质。     

Die Kristallstruktur von Aza-closo-decaboran NB9H10

The Crystal Structure of Aza-closo-decaborane, NB₉H₁₀ Aza-closo-decaborane(10), NB₉H₁₀, crystallizes in the space group P2₁/n. The NB₉ skeleton forms a distorted bicapped tetragonal antiprism with the N atom in a capping position. The structural data are compared to those of aza-closo-dodecaborane(12), NB₁₁H₁₂.     

半监督条件下基于朴素贝叶斯和Choi-Williams时频分布能量积累的雷达信号识别

针对非合作电子侦察雷达信号识别中先验信息残缺的问题,该文提出一种基于Choi-Williams时频分布(CWD)的改进半监督朴素贝叶斯的识别算法(ISNB)。首先对CWD进行降噪预处理,然后通过计算降噪后CWD不同时间下各频率采样值的积累量,从而得到CWD的能量积累量这一新特征;针对传统的半监督朴素贝叶斯(SNB)在更新训练样本集过程中会产生迭代错误的不足,通过在无标签样本集生成的置信度列表中选取置信度高的样本添加到有标签样本集中,再利用预测后的分类结果对分类器参数进行改进,进而构建改进的SNB分类器,有效解决了传统SNB算法分类精度低且分类性能不稳定的缺点。理论分析和仿真结果表明,所提方法相比于传统SNB算法均提高了3%左右;在相同信噪比下,相比于传统的主成分分析加支持向量机法,该算法具有更高的分类识别率和更好的分类性能。