Analytical estimation of measurement uncertainty in surface plate calibration by the Moody method using differential levels

Surface plate quality influences the calibration of artifacts, instruments, working gauges and, by extension, the quality of manufactured parts. A statement of uncertainty for the surface plate calibration is needed for conformance testing and for estimating uncertainty in calibrations that rely on the surface plate. An analytical approach to the estimate of uncertainty for a common measurement method is given. The residual height at each position on the surface is expressed in terms of the measurement parameters and the measured angles. Uncertainty of each residual height value is then derived following the common methods for propagation of uncertainty. The maximum uncertainty is at the center of the surface and the calculated bounds on error compare well with values of closure from actual measurements. The uncertainty of height values is proportional to the spacing of the measurement positions and to the squareroot of the number of positions. Using data from many plates of various size and quality, a generalized uncertainty in flatness for the measurement method was estimated. The derivations also allow calculations for specific applications. Finally, a method is proposed for reporting uncertainty in surface slope which is required for estimating uncertainties of items calibrated on a surface plate.     

巨豆粉代替尿素酶法测定复混肥料中的尿素态氮

通过实验找到用巨豆粉测定尿素态氮的适宜反应条件，并讨论了复混肥料中一些常见的组分对该法的干扰及其消除方法。     

基于人机工程学的消防车器材布局优化设计研究

消防车的器材布局设计直接影响着消防员的战斗效率和安全健康。在对消 防车器材布局空间人机工程学分析的基础上,结合器材的布置原则、“人”的因素及消防车的 器材类别,提出了消防车空间设计和器材布局的设计建议。以某型消防车的器材布局设计改 进为实例,应用Jack 软件对布局进行了视域和可达域分析,验证了改进方案的合理性。     

自存工况下自升式平台关键结构强度分析

针对一艘独立三桩腿的齿轮齿条式自升式钻井平台,利用ANSYS软件分析了自存工况下,在风浪流等综合载荷作用下的钻井平台整体关键结构强度和平台桩腿稳定性,为平台的安全使用和升级改造提供了理论依据。     

Topics in Structural Chemistry through After-Dinner Humor

Some of the best stories told by Jack Dunitz in after-dinner speeches introduce comments and personal views on aspects of contemporary structural chemistry: crystal structure analysis and prediction, facts and fallacies in the study of intermolecular bonding, and theories of crystal formation, from nucleation to growth. The role of X-ray crystallography in the determination of the structure of matter at a molecular level is highlighted, with broad and pervasive bearings on present-day applications in materials science. A short essay presents the results of molecular simulations on the stability of small molecular clusters with crystalline structure: the future seems to lay not in the analysis of crystal structures after they are formed, but in the study of autocatalytic insurgence of long-range ordering during nucleation processes.     

Explorations in the Dynamics of Crystalline Solids and the Evolution of Crystal Formation Processes

This article describes a few selected areas of research within the field of structural chemistry, with emphasis on aspects that have been influenced and inspired by the seminal work of Jack Dunitz. The topics covered include the study of dynamic properties of crystalline materials, focusing on the use of solid-state ²H NMR spectroscopy to unravel details of dynamic hydrogen-bonding arrangements in crystalline alcohols and amino acids, as well as the use of in situ Raman microspectrometry to explore molecular transport processes through porous crystals. A case study involving the determination of both structural properties and dynamic properties of a material (ammonium cyanate) that is not amenable to structural characterization by single-crystal X-ray diffraction is also presented. On the theme of exploring the time evolution of crystallization pathways, the recent development and application of in situ solid-state NMR techniques for mapping time-dependent changes that occur in the solid phase during crystallization processes are discussed. Finally, the article contemplates the prospects for deriving a fundamental physicochemical understanding of crystal nucleation processes, which is identified as perhaps the most significant challenge in structural chemistry in the next few decades.     

人因特性驱动蚁群算法的操作界面布局优化

以优化复杂机械设备人机界面,提高操作效率、降低操作人员能耗为目的,结合人因工程分析软件Simens Jack(以下简称为Jack)可视域与可达域分析,构建机械设备操纵界面布局优化函数。根据操纵器在空间中位置关系,引入约束条件,对操纵器布局位置进行限定。应用蚁群算法正反馈机制与启发式搜索方法,对目标函数进行求解,将迭代结果映射为操纵器布局排列。通过以上方法对某隧道救援钻机操作台进行改进,将优化后的人机界面与原操作界面在Jack软件中进行对比仿真,验证方法的可行性。     

基于Jack远程监控操作台人机工效评价

为了提高远程监控操作员的工作舒适度，以DK公司远程监控中心操作台为研究对象，以工效学为理论依据，利用Jack软件，进行数字人模型的建立，对远程监控操作台建模仿真。对数字人工作时的舒适度和疲劳度进行检验，发现其存在的问题，并提出改善方法。结果表明，通过对座椅的构造优化与尺寸调节、对数字人安装脚垫板等方式，可以显著提高数字人的舒适度。     

Performance history of The Geysers steam field, California, USA

The performance of Calpine's Geysers steam field from startup in 1960 to 2008 is described in this paper. Since October 2003, Calpine has received approximately 482 L/s of tertiary-treated reclaimed water from the City of Santa Rosa. To accommodate and derive benefit from this water, Calpine has converted 20 wells (ten producers, six shut-in, two observation, and two suspended wells) to high-rate injection service. Additional nine wells were also converted to low-rate injectors that receive 12.6 L/s or less. Annual recovery factors (i.e., fieldwide increase in annual steam production divided by annual injection) for the first 5 years of Santa Rosa Geysers Recharge Project (SRGRP) operation have been estimated at 17.6%, 26.1%, 37.1%, 39% and 44.6%, respectively; reasonably close to or slightly higher than the values, predicted prior to SRGRP startup. Using a revised definition that includes the amount of un-boiled water in the reservoir, the annual recovery factors turn out to be 17.6%, 16.1%, 14.6%, 12.4% and 12.2% from year one through year five. Improvements in the wellfield, water injection, and power plant modifications from January 1995 through December 2008 are also discussed in this paper.