用声速法在线测量强酸溶液的浓度

超声波技术为化工溶液浓度的测量提供了可能。由于强酸中超声波速度在一定浓度上存在着极值现象，因此超声波测量溶液浓度的技术只适用于某些浓度范围。作者根据超声波速度与强酸溶液浓度的关系提出了一种用声速法测量强酸浓度的方法，该法特别适用于化工厂生产液的在线测量。     

Ｈ∞辨识中的代数方法*

本文讨论了单输入、单输出、离散、时不变因果系统的面向控制的Ｈ∞辨识问题，在该问题中，中心估计是最优的，插值估计是次优的，但一般都难以求取，本文提出了非插值类的代数算法，该算法计算量小，所得模型简单且估计出的Ｗｏｒｓｔ－Ｃａｓｅ误差较小，该算法是收敛的，因而具有较好的实用价值。     

当代多芯片组装技术

与传统的封装技术相比，多芯片组装技术具有更高的封装密度和更优异的性能。多芯片组装技术正在蓬勃发展，归当代的代表性技术。     

汽轮机叶片叶型测量综述

详细介绍了目前国内外汽轮机叶片和飞机叶片的主要测量方法的测量原理及每１种测量方法能达到的测量精度。最后，作者对叶片未来测量仪器的设计提出了一些自已的观点和建议，对叶片测量仪器的设计具有一定的参考价值。     

光缆拉伸应变分布测量的新方法：布里渊光纤时域分析技术

通信光缆拉伸应变分布测量对于保证光纤通信线路的长期可靠性具有十分重要的意义。文章论述了布里渊光纤时域分析技术的背景、现状、描述了该技术的基本原理，存在的问题以及目前研究的最新进展。     

具有结构不确定性的输出反馈线性系统的鲁棒稳定性分析

基于向量的幂变换方法，对具有结构不确定性的输出反馈线性系统的鲁棒稳定性问题作了分析。单参数摄动时给出了闭环系统鲁棒稳定的充要条件，多参数摄动时得到了保证系统鲁棒稳定的充分条件，导出了闭环系统鲁棒稳定区域的一种代数表达形式。最后给出了实例。     

Predicting Variability in a Lake Ontario Phosphorus Model

The prediction of a model always has a degree of uncertainty. Because the level of uncertainty is inversely related to the value of information contained in the prediction, there is a need to quantify the uncertainty. One approach to estimate prediction uncertainty is first-order error analysis. In this method, the error in a characteristic (variable or parameter) is defined by its first nonzero moment (the variance). Errors are propagated through the model using first-order terms in the Taylor series, and the variances are then combined to yield the total prediction uncertainty. An alternative approach to model prediction error analysis is Monte Carlo simulation. In this technique, probability density functions are assigned to each characteristic (variable or parameter), reflecting the uncertainty in that characteristic. Then, values are randomly selected from the distribution for each term and inserted into the model, to calculate a prediction. Repeating this process a number of times produces a distribution of predicted values, which reflects the combined uncertainties. These two approaches (first-order error analysis and Monte Carlo simulation) are applied to Lake Ontario data using a steady state mass balance phosphorus model. Comparisons are made which suggest guidelines for the use of each.     

Development of Laser-Induced Capillary Wave Method for Viscosity Measurement Using Pulsed Carbon Dioxide Laser

A new experimental apparatus, based on the laser-induced capillary wave method involving the use of a pulsed carbon dioxide laser (wavelength 10.6 m, pulse width 50 ns, power 65 mJ) as a heating source has been developed. Since the present technique is applicable to a wide range of viscosity, this method is applicable to the process in which the viscosity drastically changes within a short period of time. In this method, interfering laser beams heat a liquid surface and generate a capillary wave (the wavelength can be adjusted from 20 to 200 m) caused by a spatially sinusoidal temperature distribution. The temporal behavior of the capillary wave is detected by a diffracted probe beam (He–Ne laser, 15 mW) at the heated area. The dynamics of the capillary wave provide information regarding thermophysical properties such as viscosity and surface tension. In the present study, several liquid samples spanning the viscosity range from 0.33 to 7080 MPa·s (e.g., acetone, toluene, 1-hexanol, ethylene glycol, JS1000, and JS14000) were investigated at room temperature. The detected signals for several liquid samples exhibiting a wide range of viscosity agree well with theoretical calculations, taking into account the influence of the distribution of surface tension.     

Flow condensation heat transfer coefficients of R22, R134a, R407C, and R410A inside plain and microfin tubes

Flow condensation heat transfer coefficients (HTCs) of R22, R134a, R407C, and R410A inside horizontal plain and microfin tubes of 9.52 mm outside diameter and 1 m length were measured at the condensation temperature of 40 °C with mass fluxes of 100, 200, and 300 kg m⁻² s⁻¹ and a heat flux of 7.7–7.9 kW m⁻². For a plain tube, HTCs of R134a and R410A were similar to those of R22 while HTCs of R407C are 11–15% lower than those of R22. For a microfin tube, HTCs of R134a were similar to those of R22 while HTCs of R407C and R410A were 23–53% and 10–21% lower than those of R22. For a plain tube, our correlation agreed well with the present data for all refrigerants exhibiting a mean deviation of 11.6%. Finally, HTCs of a microfin tube were 2–3 times higher than those of a plain tube and the heat transfer enhancement factor decreased as the mass flux increased for all refrigerants tested.     

Measuring dimensions of perceived e-business risks

The risks to e-business from breaches of security and privacy are well known. However, research has given very little attention to other important e-business risks. Using a socio-technical approach, in this study we survey a diverse sample of almost 200 participants to rate their perception of 16 e-business risks, compiled from the research and practitioner literature. Strategic risks, organizational risks and e-business policy risks emerged as the three underlying dimensions of e-business risk. In terms of the socio-technical model, strategic risks focus on the actor-structure component, and policy risks focus on the task-structure component. Organizational risks cover a wide spectrum of socio-technical components such as technology, actor-technology, technology structure and task-actor. The main contribution of this study is a multi dimensional scale of e-business risk perception. Practitioners can benefit by focusing their risk management efforts on the three dimensions of e-business risk, which are easier to manage than a long checklist of unrelated risks. Researchers benefit from a raised awareness on the importance of strategic and organizational risk factors in addition to policy risk factors for e-business risk management. A model that incorporates the three dimensions of e-business risks and shows theoretically based relationships with control mechanisms, trust, perceived uncertainty and profitability is proposed for testing in future research.