氢/空气火焰在半开口有障碍管道中的传播特性

针对氢／空气混合物，通过实验研究了其预混火焰在半开口管道中的火焰传播加速现象。结果表明，火焰传播状态随着氢气当量比的变化而发生改变。当氢／空气混合物被点燃后，由于障碍物的扰动，火焰在管道中不断加速传播，并最终到达一准稳态传播。在氢气当量比0．34附近时，火焰速度发生跃变。当氢气当量比足够大时，火焰传播由爆燃态转变为爆轰态。在本实验条件下，爆燃转准爆轰的临界条件是d/λ=2.6(d是圆环形障碍物内径，λ是爆轰格胞尺度）。障碍物阻塞比的变化对最大火焰速度和压力提升的影响不明显。     

鱼雷罐喷粉预处理优化研究

在已经得到的描述鱼雷罐喷粉处理基本参数具体表达式的基础上，运用多目标非线性优化方法，对工艺操作参数进行优化。     

OFDM技术及其应用

首先对OFDM的发展以及应用做了简要的介绍,然后讨论了当前OFDM研究过程中的两个关键技术问题,最后展望了OFDM的未来发展。     

Application of Wavelet Packet De-noising in Time-Frequency Analysis of the Local Wave Method

The local wave method is a very good time-frequency method for nonstationary vibration signal analysis. But the interfering noise has a big influence on the accuracy of time-frequency analysis. The wavelet packet de-noising method can eliminate the interference of noise and improve the signal-noise-ratio. This paper uses the local wave method to decompose the de-noising signal and perform a time-frequency analysis. We can get better characteristics. Finally, an example of waveletpacket denoising and a local wave time-frequency spectrum application of diesel engine surface vibration signal is put forward.     

塔里木盆地塔中沙漠区高分辨率地震勘探效果

塔中沙漠区地表被北东—南西向条带状沙层所覆盖,地形起伏剧烈,松散沙层厚度变化巨大,给地震资料采集、处理、解释带来了很大的困难。通过联合攻关,从地震波激发能量下传和反射波接收的研究入手,实现了全部潜水面以下激发,因地制宜、避高就低埋置检波器优化观测系统;针对该区石炭系和志留系低幅度构造、薄储层圈闭难以落实,奥陶系内幕地震资料反射波能量弱、信噪比低、叠加成像困难等问题,开展了沙丘对地震波吸收衰减分析和补偿技术、地表一致性处理技术、多域迭代静校正技术、精细速度场模型确立和偏移成像等配套技术的研究开发与应用。从而极大地改善了塔中沙漠区地震资料的品质,使中深层的石炭系、志留系、奥陶系对应的地震剖面主频从18～20Hz提高到36～40Hz;形成了塔中沙漠区油气勘探技术系列,精细刻画了塔中Ⅰ号带,锁定了油气勘探目标,推动了台盆区油气勘探再掀新高潮。     

Production of biodiesel from waste fryer grease using mixed methanol/ethanol system

Transesterification of waste fryer grease (WFG) containing 5–6 wt.% free fatty acid (FFA) was carried out with methanol, ethanol, and mixtures of methanol/ethanol maintaining the oil to alcohol molar ratio of 1:6, and initially with KOH as a catalyst. Mixtures of methanol and ethanol were used for transesterification in order to use the better solvent property of ethanol and rapid equilibrium using methanol. Formation of soap by reaction of FFA present in WFG with KOH instigated difficulty in the separation of glycerol from biodiesel ester. To untangle this problem, two-stage (acid and alkali catalyzed) method was used for biodiesel synthesis. More than 90% ester was obtained when two-stage method was used compared to ∼ 50% ester in single stage alkaline catalyst. In the case of mixed alcohol, a relatively smaller amount of ethyl esters was formed along with methyl esters. Acid value, viscosity, and cetane number of all the esters prepared from WFG were within the range of the ASTM standard. Esters obtained from WFG showed good performance as a lubricity additive.     

八钢高炉无料钟炉顶的装料制度

以八钢高炉炼铁实践为依据，系统研究和分析了八钢2号和3号高炉炉顶设备装料制度对高炉冶炼的影响。认为高炉操作制度是当前高炉炼铁的主要技术之一，也是影响高炉焦比主要技术经济指标的重要因素。在原燃料和装备水平一定的条件下，合理的操作制度对高炉的技术经济指标起到决定性的作用。     

济钢350m^3高炉高富氧生产技术

分析了济钢350m^3高炉高富氧对产量,理论燃烧温度,炉况顺行状况,焦比和生产效益的影响,高富氧可提高产量,但升高焦比和高炉理论燃烧温度,一定程度上影响高炉顺行,存在富氧效益最大化的适宜富氧率.高炉生产应低富氧高喷煤,根据钢目前的情况,富氧率经2%-3%为宜.     

A Dynamic Dictionary for Priced Information with Application

In this paper we design a dynamic dictionary for the priced information model initiated by Charikar et al. Assume that a set S consisting of n elements is given such that each element has an associated price, a positive real number. The cost of performing an operation on elements of S is a function of their prices. The cost of an algorithm is the sum of the costs of all operations it performs. The objective is to design algorithms which incur low cost. In this model we propose a dynamic dictionary, supporting search, insert and delete, for keys drawn from a linearly ordered set. As an application we show that the dictionary can be used in computing the trapezoidal map of a set of line segments, a fundamental problem in computational geometry.     

鄂尔多斯西缘前陆盆地巨厚黄土地区地震采集技术

鄂尔多斯西缘前陆盆地表层地质地貌极其复杂，有巨厚黄土区、黄土-沙漠区及山前砾石-黄土区，独特的黄土地貌使得地震采集面临着诸多技术难题。根据以往巨厚黄土地区地震采集经验，采用多种方法系统地开展黄土表层结构精细调查，深入研究黄土地球物理特征及激发因素与表层黄土结构之间的关系，优选激发井位和井深，确保了激发效果；采用小道距、三线小线距、高密度空间采样技术，获得了高信噪比、高分辨率地震资料。研究表明，巨厚黄土地区地震采集时应优选激发井位和岩性，合理选择激发井深；坚持多深井组合激发、单井药量不宜过大总药量要大两项基本原则；采用高密度采样技术，提高采集资料的覆盖次数和信噪比。图10表1参15