Improvement of quantitative analysis of molybdenum element using PLS-based approaches for laser-induced breakdown spectroscopy in various pressure environments

An experimental setup has been designed and realized in order to optimize the characteristics of laser-induced breakdown spectroscopy system working in various pressure environments. An approach combined the normalization methods with the partial least squares(PLS) method are developed for quantitative analysis of molybdenum(Mo) element in the multi-component alloy,which is the first wall material in the Experimental Advanced Superconducting Tokamak. In this study, the different spectral normalization methods(total spectral area normalization,background normalization, and reference line normalization) are investigated for reducing the uncertainty and improving the accuracy of spectral measurement. The results indicates that the approach of PLS based on inter-element interference is significantly better than the conventional PLS methods as well as the univariate linear methods in the various pressure for molybdenum element analysis.     

小浪底水力发电厂机组动平衡试验

小浪底水力发电厂5号机组投运以来,运行工况不够理想,上机架振动和上导摆度均超标,水导运行温度居高不下。通过检查发现5号机组下机架倾斜,因此,曾一度把关注的焦点放在处理下机架的问题上。5号机组大修后,调整了下机架的水平,但仍未解决问题。通过认真地研究和多次试验,发现机组存在动不平衡。通过动平衡试验和几次配重。彻底解决了由于机组动不平衡造成的上机架振动、上导摆度、水导运行温度等一系列问题。     

Influence of a Static Magnetic Field on Laser Induced Tungsten Plasma in Air

In this work,laser induced tungsten plasma has been investigated in the absence and presence of 0.6 T static transverse magnetic field at atmospheric pressure in air.The spectroscopic characterization of laser induced tungsten plasma was experimentally studied using space-resolved emission spectroscopy.The atomic emission lines of tungsten showed a significant enhancement in the presence of a magnetic field,while the ionic emission lines of tungsten presented little change.Temporal variation of the optical emission lines of tungsten indicated that the atomic emission time in the presence of a magnetic field was longer than that in the absence of a magnetic field,while no significant changes occurred for the ionic emission time.The spatial resolution of optical emission lines of tungsten demonstrated that the spatial distribution of atoms and ions were separated.The influence of a magnetic field on the spatial distribution of atoms was remarkable,whereas the spatial distribution of ions was little influenced by the magnetic field.The different behaviors between ions and atoms with and without magnetic field in air were related to the various atomic processes especially the electrons and ions recombination process during the plasma expansion and cooling process.     

新型网络终端管理系统体系结构及流程实现

现如今,网络技术已经得到了空前的发展,随着网络技术的逐渐革新,计算机信息资源的传播更为普遍,与我们的生活存在着千丝万缕的联系。我国的计算机规模随着技术发展的成熟逐步扩大,虽然PC机的性能与过去相比已经取得了明显的进步,但在这些年的发展中,人们对于网络终端技术的要求更高,以往的PC机性能很难满足人们的要求,它的缺陷日益暴露,例如客户端的硬件设施必须要随网络客户端和服务终端的升级而升级,这对系统资源造成了浪费,增加网络系统的管理难度。为了解决这个难题,新型网络终端管理系统便应运而生,本文主要针对新型网络终端管理系统进行讨论。     

西霞院水电站监控系统设计

为更加科学、合理地利用黄河水资源，发挥小浪底水利枢纽的发电效益，建设了西霞院反调节水电站。根据西霞院水电站监控与闸门监控在同一平台上高度集控的特点，从网络结构、数据库、人机界面、集控实现等几个方面介绍了西霞院水电站监控系统的设计。     

新型网络终端管理系统体系结构及流程实现

现如今,网络技术已经得到了空前的发展,随着网络技术的逐渐革新,计算机信息资源的传播更为普遍,与我们的生活存在着千丝万缕的联系。我国的计算机规模随着技术发展的成熟逐步扩大,虽然PC机的性能与过去相比已经取得了明显的进步,但在这些年的发展中,人们对于网络终端技术的要求更高,以往的PC机性能很难满足人们的要求,它的缺陷日益暴露,例如客户端的硬件设施必须要随网络客户端和服务终端的升级而升级,这对系统资源造成了浪费,增加网络系统的管理难度。为了解决这个难题,新型网络终端管理系统便应运而生,本文主要针对新型网络终端管理系统进行讨论。     

Effect of parameter setting and spectral normalization approach on study of matrix effect by laser induced breakdown spectroscopy of Ag–Zn binary composites

The complex nature of laser-material interaction causes non-stoichiometric ablation of alloy samples.This is attributed to matrix effect, which reduces analyzing capability. To address this issue, the analytical performance of three different normalization methods, namely normalization with background, internal normalization and three point smoothing techniques at different parameter settings is studied for quantification of Ag and Zn by Laser induced breakdown spectroscopy(LIBS).The LIBS spectra of five known concentration of silver zinc binary composites have been investigated at various laser irradiances(LIs). Calibration curves for both Ag(I) line(4d~(10)5s~2S_(1/2)→4d~(10)5p~2P_(1/2) at 338.28 nm) and Zn(I) line(4s5s~3S_1→4s4p~3P_2 at 481.053 nm) have been determined at LI of 5.86?×?10~(10)W cm~(-2). Slopes of these calibration curves provide the valuation of matrix effect in the Ag–Zn composites. With careful sample preparation and normalization after smoothing at optimum parameter setting(OPS), the minimization of sample matrix effect has been successfully achieved. A good linearity has been obtained in Ag and Zn calibration curve at OPS when normalized the whole area of spectrum after smoothing and the obtained coefficients of determination values were R~2?=?0.995 and 0.998 closer to 1. The results of matrix effect have been further verified by analysis of plasma parameters. Both plasma parameters showed no change with varying concentration at OPS. However, at high concentration of Ag, the observed significant changes in both plasma parameters at common parameter setting PS-1 and PS-2 were the gesture of matrix effect. In our case, the better analytical results were obtained at smoothing function with optimized parameter setting that indicates it is more efficient than normalization with background and internal normalization method.     

小浪底与西霞院水库联合调度程序算法探讨

为更加科学、合理地利用黄河水资源，解决水调与电调的矛盾，使小浪底水利枢纽在发挥诸多社会效益的同时充分发挥发电的经济效益，建设了小浪底水利枢纽集中控制中心，通过联合调度程序实现对小浪底水利枢纽、西霞院反调节水库的集中监控和优化调度。文中探讨了优化调度软件编程的计算机算法。     

小浪底与西霞院水库联合调度程序算法探讨

为更加科学、合理地利用黄河水资源,解决水调与电调的矛盾,使小浪底水利枢纽在发挥诸多社会效益的同时充分发挥发电的经济效益,建设了小浪底水利枢纽集中控制中心,通过联合调度程序实现对小浪底水利枢纽、西霞院反调节水库的集中监控和优化调度。文中探讨了优化调度软件编程的计算机算法。     

2020年全球火山活动综述

本文通过对2020年全球活动火山监测信息进行统计分析,确定全年共有27个国家的89座火山发生了喷发活动,按照火山预警等级来标识火山的危险程度,根据各个火山预警等级在全年875次监测信息公告中的出现次数,将这89座活动火山按危险程度划分为4类,并对每类火山活动做出了详细描述.