用倒计时法实现一定时间间隔的测量

针对被检交流稳压电源输出频率稳定度测试,即测试输出频率随时间的变化情况,本文充分开发和利用LabVIEW 8.5开发环境中已用时间函数,采用倒计时显示剩余时间的方法,设计了实现任意设置时间间隔内,对同一被测对象进行多次测量、数据处理、存盘的程序.该程序简单实用,提高了检定系统的自动化程度,对使用者带来极大的方便,具有较高的应用、借鉴价值.     

Improving the precision of optical metrology by detecting fewer photons with biased weak measurement

In optical metrological protocols to measure physical quantities, it is, in principle, always beneficial to increase photon number n to improve measurement prec...     

双电动机拖动不同步故障剖析及对策

介绍了韶钢炼铁厂高炉主卷扬双电动机拖动时出现的不同步故障,从原设计中变频器主从控制原理、主从通信的方式及编码器反馈通道等方面详细地分析了产生故障的原因.并根据其故障原因提出了使用SLB板代替SCB2板、建立交频器之间光纤环网通信以减少外部信号的干扰以及利用DTI板切换编码器反馈信号等改造方案,并加以实施,取得了较好的改造效果.同时为其他工艺设备的改造提供了有力的技术支持.     

Sensing Matrix Optimization for Multi-Target Localization Using Compressed Sensing in Wireless Sensor Network

In the multi-target localization based on Compressed Sensing(CS), the sensing matrix’s characteristic is significant to the localization accuracy.To improve the CS-based localization approach’s performance, we propose a sensing matrix optimization method in this paper, which considers the optimization under the guidance of the t%-averaged mutual coherence. First, we study sensing matrix optimization and model it as a constrained combinatorial optimization problem. Second, the t%-averaged mutual ...     

高压电机应用变频器后的继电保护整定

高压变频器在泵类及风机类负载中得到广泛的应用后,对电机的传统保护方式产生了很大影响.笔者根据变频器的构成原理和电机的保护特性,提出了高压电机应用变频器后的电流速断和过流保护的计算方法.     

基于线性预测残差倒谱的基音检测

传统的基音检测算法对含噪语音的检测结果较差,本文在线性预测倒谱方法的基础上采用基于线性预测残差倒谱的方法对含噪语音进行基音检测。实验结果表明,该方法使基音峰点更加清晰,提高了基音检测的精度。     

222Rn在大气输运研究中的示踪应用

本文简要回顾了222Rn及其子体示踪应用的主要方面,介绍了国内外对利用222Rn及其子体在预报地震和大气物质输运研究这两方面的工作.对这些示踪应用而言,要进行准确的定量分析和数值模拟,必须对222Rn及其子体在大气中的输运规律有细致的了解,这一点可以通过研究其动力学特征,建立输运模型来实现.本文中列举了部分对222Rn及其子体输运模式的研究,对比上层大气中的简单输运模型,一个比较全面的222Rn输运模型还需要考虑地表层结大气中的复杂的动力学因素,并将其作为222Rn在上层大气输运模型中的下垫面边界条件.     

钚中毒治疗药物的研究现状

根据Pu(Ⅳ)与Fe(Ⅲ)在配位化学和生物化学性质上的相似性,钚中毒治疗药物的研究可从仿生化学角度设计钚螯合物的配基,并且兼顾到药物的有效性和安全性.本文简要介绍了钚的毒性和钚中毒的治疗方法,比较了儿茶酚胺(CAM)类配基、二羟基对苯二酰胺(TAM)类配基和羟基吡啶酮(HOPO)类配基的钚螯合剂的疗效及毒性,其中3,4,3-LI-(1,2-HOPO)对钚的促排效果最好,优于DTPA,但其毒性远大于DTPA.要开展新的其它类型的钚螯合剂的研究,以寻找高效低毒药物.     

Key Residues Affecting Binding Affinity of Sirex noctilio Fabricius Odorant-Binding Protein (SnocOBP9) to Aggregation Pheromone

Sirex noctilio Fabricius (Hymenoptera Siricidae) is a major quarantine pest responsible for substantial economic losses in the pine industry. To achieve better pest control, (Z)-3-decen-ol was identified as the male pheromone and used as a field chemical trapping agent. However, the interactions between odorant-binding proteins (OBPs) and pheromones are poorly described. In this study, SnocOBP9 had a higher binding affinity with Z3D (Ki = 1.53 ± 0.09 μM) than other chemical ligands. Molecular dynamics simulation and binding mode analysis revealed that several nonpolar residues were the main drivers for hydrophobic interactions between SnocOBP9 and Z3D. Additionally, computational alanine scanning results indicated that five amino acids (MET54, PHE57, PHE71, PHE74, LEU116) in SnocOBP9 could potentially alter the binding affinity to Z3D. Finally, we used single-site-directed mutagenesis to substitute these five residues with alanine. These results imply that the five residues play crucial roles in the SnocOBP9-Z3D complex. Our research confirmed the function of SnocOBP9, uncovered the key residues involved in SnocOBP9-Z3D interactions, and provides an inspiration to improve the effects of pheromone agent traps.