经营成本变化对大庄电站经济效益的影响

我国水电蕴藏量居世界首位。近年来水电事业发展迅速,中小型水电项目的经济效益是投资者最为关注的内容,是影响投资者决策的首要因素。本文根据大庄水电站实际年运行费与设计阶段的经营成本对比,分析了经营成本变化的原因以及对项目经济效益的影响。分析结果显示,项目FIRR低于原设计标准,但高于新的财务基准收益率,项目连续亏损尚有其他原因,应做进一步分析。同时提出对经营成本与营业成本两个概念进行理论研究的建议。     

恒定应力加速寿命试验算法探讨

恒定应力加速寿命试验具有试验方法简单、理论成熟、得到信息多、试验结果较为准确等优点。本文利用三种被广泛运用的统计推断方法对同一恒定应力加速寿命试验结果进行推断,分析比较算法的优劣：在样本量较小的情况下极大似然估计优于线性无偏估计,但是当各应力水平下的样品失效数较大时,极大似然估计与线性无偏估计几乎等效,而线性回归的方法计算较为简单,但是在应力水平较少的情况下误差较大。     

A minimum Hellinger distance estimator for stochastic differential equations: An application to statistical inference for continuous time interest rate models

A minimum disparity estimator minimizes a φ-divergence between the marginal density of a parametric model and its non-parametric estimate. This principle is applied to the estimation of stochastic differential equation models, choosing the Hellinger distance as particular φ-divergence. Under an hypothesis of stationarity, the parametric marginal density is provided by solving the Kolmogorov forward equation. A particular emphasis is put on the non-parametric estimation of the sample marginal density which has to take into account sample dependence and kurtosis. A new window size determination is provided. The classical estimator is presented alternatively as a distance minimizer and as a pseudo-likelihood maximizer. The latter presentation opens the way to Bayesian inference. The method is applied to continuous time models of the interest rate. In particular, various models are tested using alternatively tests and their results are discussed.     

协整检验在SAS／ETS中的实现

SAS系统是大型集成的应用信息系统,拥有完备的数据访问、数据管理、数据分析和数据呈现功能。利用SAS的ETS模块做协整检验,不仅可以充分实现模型的设定和多样的估计,而且可以集成其他模块完善输出结果。     

基于声发射和神经网络的复合材料冲击定位

为了提高复合材料结构冲击定位的精度和实时性,基于声发射和神经网络技术,提出了复合材料结构冲击定位两步法,以压电陶瓷（PZT）和自制信号采集系统替代商用声发射仪器,实现了一种能够高精度、实时、在线监测冲击的系统。用小波变换求出原点处冲击源传播到各传感器的波达时间差,用这组时间差修正其他位置上的冲击源到达各传感器的波达时间,利用修正后的波达时间,根据四点圆弧定位算法得到冲击源坐标,实现初步定位;将所求出的位置坐标作为神经网络的输入,训练之后的神经网络可以准确预测冲击位置,实现精确定位。在复合材料板上的试验表明：该方法能快速、准确地识别出冲击位置。     

Safety assessment of the NET Predesign

Work carried out by European Associations on Safety and Environment inside the EC Fusion Technology Programme and by NET has been concentrated on safety-related guidance and on safety assessment of the NET Predesign. Emphasis has been put on analysis of accident sequences of regulatory concern up to worst case accidents, including quantification of consequences to components, systems, and plant, and of doses to the public. Probabilistic safety studies for the most important systems and broadly for the entire plant have been performed to supplement the calculated accidental doses by expectation values for their occurrence rate, and to check the relevance of the reference accident sequences selected initially by judgment. Waste masses per year of operation and for decommissioning have been quantified. For two countries and according to the practices and regulations of these countries, volumes of radioactive waste packaged for final disposal have been determined.Presented at the IAEA Technical Committee Meeting on Developments in Fusion Safety, Toronto, June 7–11, 1993.     

类氖钼基态到（n＝3，4）88个能级的碰撞强度

采用“快速”扭曲波方法和程序ＭＣＤＷ（九）,计算了类氖钼基态到８８个（ｎ４）激发态能级的电子碰撞激发截面,并与国外完全相对论理论数据进行了详细比较,一般差别在１０％左右,表明作者发展与建立的一套方法和程序不仅实现了“快速”计算而且有相当高的精度。     

Surface integrity studies on abrasive water jet cutting of AISI D2 steel

This article investigates the 3D surface topography and 2D roughness profiles, and micrographs were analyzed in the abrasive water jet (AWJ) cutting of AISI D2 steel kerf wall cut surfaces by varying water jet pressures and jet impact angles. In 3D surface topography, roughness parameters such as Sq, Ssk, Sp, Sv, Sku, Sz, and Sa were improved by various jet impact angles with different water jet pressures. However, the roughness parameters Ssk and Sku strongly depend on the water jet pressure and jet impact angle. This is confirmed by kerf wall cut profile structures. Fine irregularities of peaks and valleys are found on the AWJ cut surfaces, as evident from 2D roughness profiles. The scanning electron microscope micrographs confirm the production of an upper zone not very much damaged and a lower striation free bottom zone, by using the jet impact angle of 70° with a water jet pressure of 200?MPa. Finally, the results indicate a jet impact angle of 70° maintaining the surface integrity of D2 steel better than normal jet impact angle of 90°. The results are useful in mating applications subjected to wear and friction. This has resulted in enhancement of the functionality of the AWJ machined D2 steel components.     

Social impacts of road traffic: perceptions and priorities of local residents

The assessment of the social impacts of road traffic is usually based on objective indicators or on expert judgement, without input from the affected communities. This paper considers the perceptions and priorities of local residents about traffic impacts and possible mitigation measures, using as a case study a rural area that will be affected by traffic associated with the construction of a nuclear power station. The study consisted of a qualitative phase followed by a stated preference survey. Econometric models were used to measure the relative priority of different impacts and mitigation measures. The most impactful aspects were noise, vibration and increased car or bus travel times. The most preferred measures were night-time restrictions to HGVs, parking restrictions and safety measures for pedestrians and cyclists. There were significant differences in preferences according to residence location, gender, employment status and household composition. The results provide information about aspects that tend to be aggregated in existing assessment frameworks, separating the reduction in the utility of some activities (like walking and driving) and the suppression of those activities.     

Dynamic response of Kevlar®29/epoxy laminates under projectile impact-experimental investigation

This authors of this article investigated the dynamic response of woven Kevlar®29/epoxy laminates subjected to the impact loading. The cylindrical aluminum foam projectile and steel projectile were used to exert the impulse on the laminates. Deformation/failure modes, deflections, strain histories, and failure mechanisms were obtained and discussed. The results showed that with the high toughness of Kevlar fiber, the deformation modes of the laminates exhibited some characteristics similar to the metal panel, such as large global deformation. The failure mechanisms like matrix failure, fiber splitting, and fibrillation were observed. These micron failures led to the macroscopic delamination and fracture of the laminates.