实验室质量体系的建立与运行

详细论述了质量和质量体系的基本概念、建立质量体系的必要性、质量体系的构成和建立过程、质量体系文件的编制、质量体系的运行和持续改进以及中国实验室国家认可委员会的有关政策。     

Different insights for improving part and system reliability obtained from exactly same DFOM “failure numbers”

Techniques for improving the reliability and maintainability of both nonrepairable and repairable items can be suggested by failure data analysis. It is shown that a given set of failure numbers leads to very different improvement strategies when the numbers are the times-between-successive-failures of one or more repairable items, rather than the times-to-failure of nonrepairable items. Since this should have been obvious more than 50 years ago, at the onset of formal reliability engineering activities, several reasons are proffered for the widespread and protracted misinterpretation of even the most basic—and simple!—conceptual and practical differences between nonrepairable and repairable items.     

Why is science difficult to learn? Things are seldom what they seem

Abstract The difficulties of learning science are related to the nature of science itself and to the methods by which science is customarily taught without regard to what is known about children's learning. An information processing model is proposed to guide thinking and research in this area.     

Improved Estimates for the Accuracy of Small Disjuncts

Learning systems often describe a target class as a disjunction of conjunctions of conditions. Recent work has noted that small disjuncts, i.e., those supported by few training examples, typically have poor predictive accuracy. One model of this accuracy is provided by the Bayes-Laplace formula based on the number of training examples covered by the disjunct and the number of them belonging to the target class. However, experiments show that small disjuncts associated with target classes of different relative frequencies tend to have different error rates. This note defines the context of a disjunct as the set of training examples that fail to satisfy at most one of its conditions. An empirical adaptation of the Bayes-Laplace formula is presented that also makes use of the relative frequency of the target class in this context. Trials are reported comparing the performance of the original formula and the adaptation in six learning tasks.     

Decision support in early development phases—A case study from machine engineering

In the case study presented in this paper we consider early development phases of a mechanical product. We want to evaluate different concepts and decide which one(s) to pursue. A problem in early phases is that usually no test runs are available. In our case study, based on a standard, there are ways to compute the lifetime distributions of the components of the different concepts. Some parameters needed for these computations are not known precisely. Unfortunately, the lifetime distributions of the components are highly sensitive to these parameters. Our approach is to equip these parameters with distributions. These distributions would be called prior distributions in Bayesian terminology, but no update is possible since no test runs are available. Our approach implies that the distribution of the system lifetime for each concept is random, i.e. we get random elements in the space of lifetime distributions. Using Monte-Carlo simulations, we demonstrate several ways to compare the random lifetime distributions of the concepts. Some of these comparisons use stochastic orderings. We also introduce a new stochastic ordering which is particularly suitable for reliability purposes. Our case study, consisting of three scenarios, allows us to demonstrate some conclusions that can be reached.     

Do 9-month-old infants expect distinct words to refer to kinds?

In 3 experiments, 9-month-old infants' expectations for what distinct count noun labels refer to were investigated. In Experiment 1, a box was opened to reveal 2 objects inside during familiarization: either 2 identical objects or 2 different objects. Test trials followed the same procedure, except before the box was opened, the contents were described using 2 distinct labels ("I see a wug! I see a dak!") or the same label twice ("I see a zav! I see a zav!"). Infants who heard a label repeated twice looked longer at 2 different objects versus 2 identical objects, whereas infants who heard 2 distinct labels showed a different pattern of looking. Experiments 2 and 3 presented infants with object pairs that only differed in shape or color, and it was found that infants expected the different-shaped (but not the different-colored) objects to be labeled by distinct count nouns. Because the property of shape is a cue to kind membership and the property of color is not, these results suggest that even at the beginning of word learning, infants may expect distinct labels to refer to distinct kinds of objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

S7-1200利用高速脉冲输出方式实现打印

本文介绍SIEMENS S7-1200利用高数脉冲（Pulse Train Output,PTO）功能与MCU进行通讯的方法,具体介绍其中的一个应用：用PTO实现S7-1200的字符打印输出。     

Comparison of mainline and alternate approaches to fusion energy

The tokamak and tandem mirror concepts are compared with alternate confinement concepts using the criteria established in DOE/ET-0047, An Evaluation of Alternate Magnetic Fusion Concepts 1977. The concepts are evaluated and rated in each of three broad categories: confidence in physics and technology, and reactor desirability. The STARFIRE and MARS reactors are used as a basis for comparing the mainline tokamak and tandem mirror concepts with the alternate concepts evaluated in DOE/ET-0047. Two recent alternate concepts, theohmically heated toroidal experiment (OHTE) and thecompact reversed field pinch reactor (CRFPR), are also evaluated. Results indicate that the physics of the mainline tokamaks and tandem mirrors is better understood than that of most alternate concepts. Both mainline concepts rank near the middle for technology requirements, and both rank near or at the bottom when compared with the reactor desirability of alternate concepts.     

冷轧处理线卷取机带头定位精度的改进

针对采用带头与卷取机芯轴橡胶套筒定位区动态接触的传统自动定位技术控制效果不好而带来带头印缺陷的问题，对其产生原因进行了分析，这是因为不同规格、钢种带钢的工艺参数不同，带钢穿带过程中在传送辊上的打滑量不同，在传输通道上的下垂量不同，带头到达卷取机芯轴定位区时计算带头位置与实际带头位置存在不稳定的偏差，因此带头定位精度不稳定。为此，开发了双动态自动定位技术，穿带过程中预留了足够的带钢打滑及下垂富余量，且带头与定位区中心线在助卷皮带咬入口静止状态下接触，消除了影响带头定位精度的主要因素，带头定位精度能稳定在±15 mm的误差范围内。实际应用效果表明，该方法可行、实用。     

基于Delphi的“虚拟胶片打印系统”的技术实现

利用Delphi和VS这两种开发平台,结合Oracle数据库,实现胶片排版、胶片调整、虚拟打印,自助打印、系统管理等功能。重点介绍了系统开发过程中针对特殊问题采用的几种技术。目的是完成胶片的集中打印管理,胶片存储备份,减少开支。