水质分析中总氮测定的不确定度评定

详细分析了总氮分析过程中可能出现的不确定度,并做了量化,找出了不确定度的主要分量,对提高总氮分析精度提出了具体的解决方法.     

Inhibitory effect of Cr（Ⅵ） on activities of soil enzymes

To evaluate the influence of various Cr(VI) concentrations (0.05, 0.25, 0.50, 1.00 and 2.00 g/kg) on the activity of soil enzymes, the activities of catalase, polyphenol oxidase, dehydrogenase, alkaline phosphatase in soils were investigated in the incubation experiment with a period of 35 d. The results indicate that all the tested Cr(VI) concentrations significantly inhibit dehydrogenase activity by over 70% after 35 d. The activity of alkaline phosphatase is slightly inhibited during the whole experiment except for on the day 7. Cr(VI) has no obvious effect on the activity of catalase in soil. On the contrary, Cr(VI) stimulates the activity of polyphenol oxidase. The results suggest that dehydrogenase activity can be used as an indicator for assessing the severity of chromium pollution. Foundation item: Projects(2006AA06Z374, 2007AA021304) supported by the National High-Tech Research and Development Program of China; Project(2008SK2007) supported by the Key Program of Science and Technology of Hunan Province, China     

基于扩展OpenC++植入技术研究与实现

本文首先介绍了常用的植入方法并分析了优缺点,重点详细分析了基于扩展OpenC+-植入技术的实现方法。     

基于AVR单片机的机车轮对踏面检测系统设计

针对机车轮对踏面曲线检测需要,提出了一种通过激光测距传感器测量轮对踏面与传感器基准线距离拟合轮对踏面曲线的方法。该系统采用了高精度激光传感器保证测量精度,采用ATMEL公司多模块集成的AVR处理器简化信号采集的硬件设计,并通过上位Pc计算机先进的Labview数据分析和重构为踏面数据分析提供了保障。     

Effect of Nanophase on the Nucleation of Intragranular Ferrite in Microalloyed Steel

MnS, MnS+V(C, N) complex precipitates in micro-alloyed ultra-fine grained steels were precisely analyzed to investigate the grain refining mechanism. The experimental results shows that MnS, MnS+V(C, N) precipitates provide nucleation center for Intra-granular ferrite (IGF), so that refined grain remarkably. Moreover, substructures such as grain boundary, sub-boundary, distortion band, dislocation and dislocation cell in austenite increased as the deformation energy led by heavy deformation at low temperatu...     

Survivability-oriented optimal node density for randomly deployed wireless sensor networks

The survivability is usually critical for wireless sensor networks,which are often deployed in the unattended harsh environment.Lots of technical schemes to improve the survivability depend on the redundant resources of the sensor networks.The amount of resources is usually determined by the node density during the deployment phase.For the random deployment and random node failures,the quantitative relation between the survivability and the node density is studied.Based on the conditional survivability,the node density to meet the required survivability level is presented.Finally,the survivability for unpredictable failures and the optimal node density to maximize the price–performance ratio are also discussed.     

Promotion of hydrogen permeation on metal-dispersed alumina membranes and its application to a membrane reactor for methane steam reforming

A mesoporous membrane for selective separation of hydrogen was prepared usingthe sol-gel method. Some metal salts such as RuCl₃, Pd(NH₃)₄Cl₂, RhCl₃,, and H ₂PtCl₆, were added to the boehmite sol and coated on a porous alumina substrate before firing at 500°C. It was foundthat the permeability of hydrogen and the separation factor for a hydrogen-nitrogen gaseous mixture of these metaldispersed membranes exceeded the limitations of the Knudsen diffusion mechanism. Although the gas permeation through a neat alumina membrane is governed by the Knudsen diffusion, the metals dispersed in alumina membranes were effective in promoting hydrogen permeation. These metaldispersed alumina membranes were also used in a membrane reactor for methane steam reforming at low temperature. In the temperature range of 300 to 500°C, the membrane reactor attained a methane conversion twice as high as the equilibrium value of the packed bed catalytic reactor system as a result of the selective removal of hydrogen from the reaction system.     

融合改造的混合式抽水蓄能与风电联合运行短期调度模型

依托规模庞大的常规水电增建混合式抽水蓄能是加快抽蓄发展的重要途径。相比传统抽蓄电站,融合改造的混合式抽水蓄能电站具有水力联系更紧密、抽-发工况转换更复杂、“量调并重”角色更鲜明等显著特点,为探索其运行模式,本文提出一种融合改造的混合式抽水蓄能与风电联合运行短期调度模型。该模型以联合体整体收益最大为目标,以机组为最小调度单元,针对常规机组和抽蓄机组的差异化运行特性分别精细化建模,并引入状态变量实现运行状态的解耦与关联切换。在模型求解方面,通过线性化方法及建模技巧将原模型转换为混合整数线性规划(Mixed Integer Linear Programming,MILP)模型,最后在JAVA环境中采用CPLEX工具进行求解。以西南某流域电站为参考构建的应用示例验证了本文模型和求解方法的有效性,可为推进常规水电站的融合改造提供借鉴。     

The Utility of Information Security Training and Education on Cybersecurity Incidents: An empirical evidence

As recent cyber-attacks have been increasing exponentially, the importance of security training for employees also has become growing ever than before. In addition, it is suggested that security training and education be an effective method for discerning cyber-attacks within academia and industries. Despite the importance and the necessity of the training, prior study did not investigate the quantitative utility of security training in an organizational level. Due to the absence of referential studies, many firms are having troubles in making decisions with respect to arranging optimal security training programs with limited security budgets. The main objective of this study is to find out a relationship between cybersecurity training and the number of incidents of organizations. Thus, this study quantified the effectiveness of security training on security incidents as the first study. This research examined the relationship among three main factors; education time, education participants, and outsourcing with numbers of cybersecurity incidents. 7089 firm level data is analyzed through Poisson regression method. Based on analysis results, we found that the negative relationship between security trainings and the occurrence of cybersecurity incidents. This study sheds light on the role of security training and education by suggesting its positive association with reducing the number of incidents in organizations from the quantitative perspective. The result of this study can be used as a referential guide for information security training decision-making procedure in organizations.

     

基于多特征与DCNN的红外SF6泄漏检测方法研究

传统SF6泄漏检测耗费大量人力物力.针对该问题,提出一种基于红外成像技术的自动检漏方法.使用混合高斯模型确认泄漏视频中的疑似泄漏区域;通过HSV颜色空间分析SF6泄漏的颜色特征;分析泄漏SF6在红外技术下的动态特性,提取其不规则运动特征;使用膨胀卷积神经网络(DCNN)作为分类器,并在视频帧上完成对泄漏区域的标注.实验结果表明,该方法通过检测不同设备、不同部位的SF6泄漏视频能够准确标记出SF6泄漏区域,检测准确率可以达到82.71％.