1553B总线分析仪校准方法的探讨

论述了１５５３Ｂ总线分析仪校准方法和内容,包括电气校准、规纺校准和噪声控制校准,并对实施过程中的关键技术作了分析。     

基于LCA的月饼包装评价

为了定量地比较不同月饼包装方式的污染物排放量,现随机抽取3种月饼包装形式--过度包装、普通包装和散装,采用生命周期分析方法,对包装产品的整个生命周期,即从原材料的提取到最终处理的全过程,进行了编目分析计算和量化比较.结果表明,市场上常见的月饼豪华包装能耗差不多是普通包装的6倍,是散装的356倍;排放SOx的量分别是普通包装和散装的9倍和158倍.可见过度包装不仅造成资源浪费,而且污染环境,应该提倡简易的普通包装和散装.     

铝合金电力电缆生命周期环境影响评价研究

目前,全球电线电缆市场规模已超过1,000亿欧元,中国的电线电缆行业产值已跃居全球第一.铝合金电缆作为一种新型的电缆,在广泛的应用过程中,其环境影响成为关注的焦点.生命周期评价是目前国际公认的对产品环境影响进行评价的基本方法,本文利用生命周期评价的方法对铝电力电缆的环境影响进行系统分析,为电缆材料的选择提供必要的决策支撑.     

包覆钯和镍后MmNi5基贮氢合金的电极特性

Ｍｍ＿（０．９）Ｔｉ＿（０．１）Ｎｉ＿（３．９）Ｍｎ＿（０．４）Ｃｏ＿（０．４）Ａｌ＿（０．３）合金包覆１０ｗｔ％钯－镍后，电极循环寿命和快速充放电性能有明显提高。同时，钯是较好的吸氢元素，这也提高了负极贮氢合金的电容量利用率。包覆钯－镍的贮氢合金电极２００次循环后电容量仅下降３％。     

Going Green at West Point: Is It Economically Beneficial? A Cost-Benefit Analysis of Installing a Wind Farm at the United States Military Academy

Abstract:

In 2007, BQ Energy communicated an idea to the United States Military Academy (USMA) at West Point, NY, about the construction of a 12.5 MW wind farm for electricity production on the western edge of its property in the training grounds near Camp Buckner. Such a project would bring educational, strategic, and potentially economic benefits to USMA, in addition to the obvious environmental benefits that would be realized by the Hudson Valley region. This article describes a quantitative approach to answer why it is financially beneficial for West Point to allow the installation of a wind farm on its property.     

Comparative study of multiaxial fatigue damage models for ductile structural steels and brittle materials

Fatigue damage prediction under a general multiaxial service loading consists of three main steps: multiaxial cycle counting, damage evaluation for an identified cycle (or reversal), and damage accumulations. The accuracy of fatigue life predictions depends on all the above steps. This paper reviews the evolutions of various multiaxial fatigue damage models, a comparative study is conducted about the physical basis, the computational efficiency, and the application range of the approaches. Based on the comparative studies, a new procedure is proposed to evaluate fatigue damage under general multiaxial random loading, which uses the Wang and Brown´s multiaxial cycle counting method for identifying cycles (or reversals), the modified procedure of the minimum circumscribed ellipse (MCE) approach for fatigue damage evaluation for an identified cycle (or reversal), and the Miner´s linear damage law for fatigue damage accumulations. By comparisons of the predicted life results with experimental results and with other approaches, it is shown that the proposed procedure is very efficient and suitable for computer aided structural optimization against fatigue.     

装备可靠性指标调整对LCC 的贡献研究及应用

为提高装备可靠性工作效率,研究了可靠性投入收益以及可靠性与寿命周期费用的关系。在此基础上,从经济性角度出发,通过以费用为牵引的逆向分析来优化论证研制阶段装备可靠性指标设计,提出了“可靠性指标调整对 的贡献率”的概念,分两种情况对其进行定义与求解,实现了可靠性要求与寿命周期费用目标的综合权衡,这对于合理确定经费投入规模,提高装备可靠性投入效益和装备效费比具有一定的参考价值。最后,通过实例对可靠性指标的调整与决策过程进行了具体演示。     

Materials selection for an automotive structure by integrating structural optimization with environmental impact assessment

Sustainable product development of an automotive structure requires a balanced approach towards technological, economical and ecological aspects. Current paper shows the application of a structural optimization system to the optimal choice of foams as a core material for sandwiches with aluminum alloy faces, for the use as floor panels in the bottom structure of a concept car. The minimization problem for the weight of the entire bottom structure under static load conditions, including stiffness, strength and buckling constraints, is formulated and solved for each material application. In addition to optimal (minimized) mass and materials' price used for selection of foams, the assessment of an environmental impact of materials-candidates during the entire life cycle of the structure is considered.     

Greenhouse gases emissions from waste management practices using Life Cycle Inventory model

When exploring the correlation between municipal solid waste management and green house gas emission, the volume and physical composition of the waste matter must be taken into account. Due to differences in local environments and lifestyles the quantity and composition of waste often vary. This leads to differences in waste treatment methods and causes different volumes of greenhouse gases (GHGs), highlighting the need for local research. In this study the Life Cycle Inventory method was used with global warming indicator GHGs as the variables. By quantifying the data and adopting a region-based approach, this created a model of household MSWM in Taipei City, a metropolitan region in Taiwan. To allow analysis and comparison a compensatory system was then added to expand the system boundary. The results of the analysis indicated that out of all the solid waste management sub-models for a function unit, recycling was the most effective method for reducing GHG emissions while using kitchen food waste as swine feeding resulted in the most GHG emissions. As for the impact of waste collection vehicles on emissions, if the efficiency of transportation could be improved and energy consumption reduced, this will help solid waste management to achieve its goal of reducing GHG emissions.     

Quantitative analysis of hydrogen in thin films using Time-of-Flight Elastic Recoil Detection Analysis

Determination of atomic concentrations in thin films is one of the key problems in materials science. Time-of-Flight Elastic Recoil Detection Analysis is a powerful method for depth profiling of light and medium mass elements in near surface layers of material. However, due to poor detection efficiency those spectrometers are not commonly used for hydrogen analysis. We have performed some improvements in order to increase detection efficiency and to make spectrometer more suitable for hydrogen analysis. The spectrometer performance was tested on amorphous Si samples implanted with H⁻ and D⁻ and hydrogenised Si standard reference sample. Sensitivity for hydrogen in silicon matrix was found to be several tens of ppm with a surface depth resolution of ~ 15 nm.     

低谷电电解制氢的生命周期3E评价

以低谷电电解制氢为研究对象,运用生命周期评价方法,对其进行经济、能源和环境3E评价,得出在整个生命周期过程中,其总的环境排放比汽油高,城市排放大大低于汽油,因此使用氢燃料可以缓解城市环境压力;能源效率为0.193,能效低的主要原因是发电效率低;就单位价格热值而言,氢气的经济性与汽油相比略有劣势.所以在目前条件下推广氢能源时机还不成熟,政府补贴是推动其发展的关键.     

包装材料的环境影响评价

对有关环境影响评价技术和指标建立方法进行了比较,从而确定出能够适合可持续包装需要的包装材料环境影响评价方法.并就基于末端模型包装生命周期影响评价和单一可持续性指标的确立进行了讨论,以便能够为实践中优选包装材料提供指导.     

On Simultaneous Confidence Intervals for Multinomial Proportions

In this article we present a method for obtaining simultaneous confidence intervals for the parameters of a multinomial distribution, and we compare this method with the one suggested recently by Quesenberry and Hurst (1964). For the usual probability levels, we find, for example, that the confidence intervals introduced here have the desirable property that they are shorter than the corresponding intervals obtained by the Quesenberry-Hurst method. We also present methods for obtaining simultaneous confidence intervals for the differences among the parameters of the multinomial distribution, and we compare these methods with the one suggested earlier by Gold (1963) for studying linear functions of the multinomial parameters. For the usual probability levels, we find that the confidence intervals introduced in the present article have the desirable property that they are shorter than the corresponding intervals obtained by the Gold method applied to the differences among the multinomial parameters. In addition, we show how the methods presented here for studying the differences among the multinomial parameters can be modified in order to obtain simultaneous confidence intervals for the relative differences among the multinomial parameters.