Improved method for roadside barrier length of need modeling using real-world trajectories

The 2011 AASHTO Roadside Design Guide (RDG) contains perhaps the most widely used procedure for choosing an appropriate length of need (LON) for roadside barriers. However, this procedure has several limitations. The procedure uses a highly simplified model of vehicle departure, and the procedure does not allow designers to specify an explicit level of protection. A new procedure for choosing LON that addresses these limitations is presented in this paper. This new procedure is based on recent, real-world road departure trajectories and uses this departure data in a more realistic way. The new procedure also allows LON to be specified for a precisely known level of protection – a level which can be based on number of crashes, injury outcomes or even estimated crash cost – while still remaining straightforward and quick to use like the 2011 RDG procedure.     

扩声系统在体育馆中的典型应用

针对体育馆举办不同类型的大型活动,分别对扩声系统的音质及扩声特点提出要求,以人声和乐器声的频率特性为依据,阐述了调音师在不同场合中对于不同的扩声对象按所要达到的扩声效果应采取的调控方法。     

NOPD技术在板结构声辐射控制中的实验研究

本文应用NOPD技术设计了一种复合多层板，按照四边固定薄板结构的模态振型，对不同的NOPD填充形式，进行声学实验，来评价不同填充形式在降低板类结构声辐射方面的效果，分析了该类板结构声振耦合的关系并验证了NOPD技术对声辐射控制的作用。     

应用音平化渣图象分析和指导转炉造渣操作

利用音平化渣图象可以清晰地看出在转炉造渣过程中何时发生喷溅，何时发生炉渣返干和何时化渣正常。应用音平化渣图象和炉渣三元相图，可以正确地分析发生喷溅和返干的原因，从而找到避免突发性喷溅和严重返干的方法。正确的枪位和炉渣碱度控制是实现平稳吹炼的保证，而音平化渣图象能帮助操作工实现这一目标。     

电源对介质阻挡放电(DBD)激发准分子(XeCl*)辐射的影响

本文对电源参数如电压幅值、频率及正负电压对介质阻挡放电激发准分子XeCl 紫外 (30 8nm)辐射的影响进行了实验研究。结果表明 ,UV辐射随电压幅度的增加而增强 ,但效率下降 ;提高频率 ,增加了放电次数 ,导致UV辐射的增强 ;此外 ,在较高的频率下 ,电压上升沿变陡 ,使得电子获得的能量主要用于原子的激发和电离。正、负电压放电的不对称源于电极结构的不对称而引起的放电过程的差异 ,负电压内电极可向放电管中馈入更多的能量 ;比较发光光谱可判断生成准分子的等离子体化学过程没有明显的差别     

Barrier layer effect of tantalum on the electromigration in sputtered copper films on hydrogen silsesguioxane and SiO2

As IC devices scale down to the submicron level, the resistance-capacitance (RC) time delays are the limitation to circuit speed. A solution is to use low dielectric constant materials and low resistivity materials. In this work, the influence of underlying barrier Ta on the electromigration (EM) of Cu on hydrogen silsesquioxane (HSQ) and SiO₂ substrates was investigated. The presence of a Ta barrier not only improves the adhesion between Cu and dielectrics, but also enhances the crystallinity of Cu film and improves the Cu electromigration resistance. The activation energy obtained suggests a grain boundary migration mechanism and the current exponent calculated indicates the Joule heating effect.     

基于计算机声卡的虚拟仪器的设计

主要介绍通过计算机的声卡来实现对虚拟仪器的设计，模拟了示波器、信号发生器和频率计等设备的基本功能，详细介绍了系统的硬件设计方法及软件流程。该系统主要适用于音频范围的各种信号的采集与产生。     

Ideal-gas thermodynamic properties for natural-gas applications

Calculating caloric properties from a thermal equation of state requires information such as isobaric heat capacities in the ideal-gas state as a function of temperature. In this work, values for the parameters of thec _p ⁰ correlation proposed by Aly and Lee were newly determined for 21 pure gases which are compounds of natural gas mixtures. The values of the parameters were adjusted to selectedc _p ⁰ data calculated from spectroscopic data for temperatures ranging from 10 to 1000 K. The data sources used are discussed and compared with literature data deduced from theoretic models and caloric measurements. The parameters presented will be applied in a current GERG project for evaluating equations of state (e.g., the AGA 8 equation) for their suitability for calculating caloric properties.     

迎接挑战加速调整不断增强冶金矿山生存与发展的能力

回顾和总结了通钢矿业公司把市场经济的挑战作为创新发展的动力和机遇，加速自适应性调整，使矿山经济步入持续、稳定、健康发展的良性轨道。     

钛合金的银脆,镉脆敏感性及其控制

利用慢应变速率拉伸技术（ＳＳＲＴ），并结合恒载实验，较全面地研究了Ｔｉ－６Ａｌ－４Ｖ合金的银脆行为、固态与液态镉脆行为，确定了应变速率、接触条件、热处理制度、试样取向、温度等因素对Ｔｉ－６Ａｌ－４Ｖ合金银脆与镉脆敏感性的影响，探讨了Ｎｉ阻挡层对控制Ｔｉ－６Ａｌ－４Ｖ合金和ＴＣ１１合金银脆开裂的作用。