铝型材隔热断桥工艺的应用

对铝型材隔热断桥生产过程中所涉及的一些因素及加工方式进行探讨,寻找提高加工工艺水平的方法,同时使这种工艺中的某些方式、方法得到广泛的认同与理解。     

HgCdTe液相外延材料组分分布的红外透射光谱评价技术

对红外透射光谱法测定HgCdTe液相外延材料纵向组分分布技术进行了深入的研究.红外透射光谱的理论计算采用了王庆学提出的组分分布模型,并考虑了光穿越组分梯度区时产生的干涉效应.通过测量同一样品在不同外延层厚度下的一组红外透射光谱,该方法的有效性得到了实验验证.进一步对组分模型中参数(即外延总厚度、组分互扩散区厚度、材料表面组分和HgCdTe层组分梯度)的拟合方法进行了讨论,并确定了各拟合参数的拟合精度.结果显示,该方法可作为测定HgcdTe液相外延材料组分特性的一种有效的测试评价技术.     

偏心轮推杆行星传动内齿圈齿廓修形的研究

提出了偏心轮推杆行星传动内齿圈齿廓修形的原则和修形方法;分别建立了齿廓分段修形的齿廓中段、齿顶段和齿根段的修形增量函数,证明了修形后的齿廓在连接点处具有连续且光滑的特性.建立了修形后同时参与啮合的活齿数计算公式,讨论了齿廓修形基本参数的确定方法及步骤,给出了偏心轮推杆行星传动内齿圈齿廓修形的实例.试验研究表明,齿廓修形后,传动的性能得到了明显改善.     

多级和多程脉冲激光放大器的逆问题

采用脉冲分割模型和逐次逼近迭代法，对任意空间和时间分布波形的激光通过任意增益分布多级和多程激光放大系统传输的逆问题，即给定输出脉冲和多级／多程放大系统参数，求输入脉冲波形和能量密度，作了详细研究和计算模拟     

拉萨河城区中段水面线计算

拉萨河城区中段防洪工程于2002—2006年分步实施,工程建成后,拉萨河城区段防洪标准从10 a一遇提高到100 a一遇。设计中通过采用北京市水利规划设计研究院自主开发的一维天然河道水面曲线计算程序进行水面线计算,弥补了二维水力学物理模型的不足,对拉萨河城区段流态及水面线等进行了研究,为工程设计提供了较为准确的水面线数据,并与物理模型相结合,二者取长补短,对太阳岛和仙足岛现状和规划工况下不同堤线等多方案进行比选,优化分析并论证了工程设计方案。     

Self Organising Maps for variable selection: Application to human saliva analysed by nuclear magnetic resonance spectroscopy to investigate the effect of an oral healthcare product

SOMs (Self Organising Maps) are derived from the machine learning literature and serve as a valuable method for representing data. In this paper, the use of SOMs as a technique for determining the most significant variables (or markers) in a dataset is described. The method is applied to the NMR spectra of 96 human saliva samples, half of which have been treated with an oral rinse formulation and half of which are controls, and 49 variables consisting of bucketed intensities. In addition, three simulations, two of which consist of the same number of samples and variables as the experimental dataset and a third that contains a much larger number of variables, are described. Two of the simulations contain known discriminatory variables, and the remaining is treated as a null dataset without any specific discriminatory variables added. The described SOM method is contrasted to Partial Least Squares Discriminant Analysis, and a list of the markers determined to be most significant using both approaches was obtained and the differences arising are discussed. A SOM Discrimination Index (SOMDI) is defined, whose magnitude relates to how strongly a variable is considered to be a discriminator. In order to ensure that the model is stable and not dependent on the random starting point of the SOM, one hundred iterations were performed and variables that were consistently of high rank were selected. A variety of approaches for data representation are illustrated, and the main theoretical principles of employing SOMs for determining which variables are most significant are outlined. Software used in this paper was written in-house, allowing greater flexibility over existing packages, and tailored for the specific application in hand.     

Impact of load profile and collector technology on the fractional savings of solar domestic water heaters under various climatic conditions

This paper investigates the influence of the domestic hot water load profiles and the collector's technology (Flat Plate FPC, Evacuated Tube ETC and Compound Parabolic CPC) on the performance of forced circulation solar water heaters operating under various climatic conditions. For this end, a typical single family house composed of five occupants located in Morocco was considered. It is found that, the solar fraction can reach annual average values of 80% especially in areas with high solar energy potential. For a fixed consumption profile, the simulations showed that the installations with FPC, ETC and CPC can consume about 1644, 1199 and 1481 kWh/year of auxiliary energy, respectively. Moreover, it is found that, adapting the consumption profile, can save approximately 43 kWh/year for FPC, 13 kWh/year for ETC and about 29 kWh/year for CPC of energy.     

Measuring the Process Yield for Simple Linear Profiles with one‐Sided Specification

Profile monitoring is mainly for checking the stability of the relationship between response and explanatory variables over time based on observed data. Linear profiles are common in calibration applications. In this study, we develop two new indices for measuring the process yield for simple linear profiles with one‐sided specification. The asymptotic distribution of the estimated index is provided. The approximate lower confidence bound for the true process yield is also obtained and used to determine whether the process yield meets the quality requirement. A simulation study is conducted to assess the performance of the proposed method. The results show that the coverage rates of the confidence intervals for all simulated cases are greater than the 95% lower limit of the stated nominal value. One real example is used to illustrate the applicability of the proposed approach. Copyright © 2013 John Wiley & Sons, Ltd.