实时调度问题的形式化描述及分析

使用自动机理论建立了一个用于分析实时调度问题的、可化简归并的形式化方法。通过分析单个任务的状态变化过程来构造实时系统的自动机。对自动机的状态进行化简和归并,大大降低了讨论实时调度问题的复杂度。以优先级上限协议为例构造了确定有穷自动机并使用该自动机证明了优先级上限协议的性质。     

除湿转轮处理冷却顶板空调系统的湿负荷

探讨了冷却顶板空调系统对新风承担湿负荷的要求及实施方案,认为吸附除湿优于冷却除湿．对利用除湿转轮处理系统湿负荷及实施方案的可行性进行了实验研究,结果表明,当夏季室外空气温度低于30℃及相对湿度低于80％时,除办公类建筑外,除湿转轮均可满足系统运行要求;对于高温高湿地区,结合前置表冷器对新风进行预处理后利用转轮除湿不仅可以满足室内湿度的要求,而且可以达到低湿度;利用改变除湿转轮再生温度和处理风量的方法可以调节室内相对湿度。     

泄爆外部压力变化特性的影响因素

为了研究可燃性气体爆炸泄爆过程中,不同因素对容器外部压力变化特性的影响,利用0.022和0.113 m3 2个球形容器进行了一系列实验。实验结果给出了不同容器容积、泄爆面积、容器结构和形式条件下容器外部压力发展历史：容器容积减小,会导致泄爆容器外部的峰值压力增大,压力变化更为迅速,持续冲击时间减小;泄爆口直径在0~0.04 m范围内增加,容器外部最大压力上升速率及峰值压力均相应增大,呈现上升的趋势但非线性,存在一个增加程度先减小后增大的驻点;容器结构和形式对泄爆过程产生显著的影响,相对于单个容器,连通容器外部峰值压力、最大压力上升速率均有较大提高;连通容器泄爆时,跟大容器泄爆相比,小容积泄爆外部最大峰值压力较大,最大压力上升速率较小。     

Hydrothermal plume anomalies along the Central Indian Ridge

Water column turbidity and temperature were investigated along the Central Indian Ridge （CIR） from 25°19＇S to 23°48＇S during a December 2005 cruise on board Chinese PJV DayangYihao. Measurements were made using NOAA＇s MAPR （Miniature Autonomous Plume Recorder） sensors during CTD casts, TV grabber operations, and tow-yo profiles, yielding the following results on hydrothermal plume anomalies： （1） Strong hydrothermal turbidity and temperature anomalies were recorded over the previously discovered Kairei （25°19.2＇S, 70°02.4＇E） and Edmond （23°52.7＇S, 69°35.8＇E） vent fields, with the plume anomalies concentrated at depths of 2150--2300 m and 2700--2900 m, respectively. The maximum height of the turbidity anomalies near the Kairei vent field recorded in December 2005 was slightly below 2100 m, which is consistent with the plume depth measured in June 2001, indicating that the Kairei plume may have maintained its buoyancy flux in the intervening 4.5 years. （2） The water column beneath the Kairei plume has background anomalies of about 0.005ANTU, whereas no such background turbidity anomalies were observed below the Edmond hydrothermal plume. （3） No visible turbidity anomalies were detected from 24°42＇S to 24°12＇S including the Knorr Seamount. Thus 24°12＇S marks the southern end of the hydrothermal plume. （4） Significant turbidity anomalies were observed at four individual sections from 24°12＇S to 23°56＇S at the depth of 2500--3000 m along the eastern rift valley wall. Whether the individual sections of anomalies are connected is still unknown due to the absence of data at the intervening gaps. If the four sections are connected with each other and are linked to the Edmond vent field farther to the north, the total along-axis length of the plume anomaly would be more than 37 km, implying a plume incidence value Ph of 0.38, greater than the predicted Ph of 0.21 --0.25 based on the spreading rate of the Central Indian Ridge.     

起升机构盘式制动器散热性能研究

本文针对起重机的工作特点,研完了提高起重机械用盘式制动器的散热性能和热负荷能力的方法,给出了曲线通风道的设计公式,并设计了直径为560mm的三种不同结构型式制动盘——实心制动盘、直通风道制动盘和曲线通风道制动盘。最后,从理论上和实验中评定了它们的散热性能和热负荷能力,得到的结论是:曲线通风道制动盘的散热性能最好和热负荷能力最高。     

室内火灾时通风状况对燃烧速率的影响

在小尺寸实验箱内综合研究了燃料的质量燃烧速率(?)随通风因子A H~(1/2)和通风口位置高度h的变化。发现因h的不同可改变烟气层对火焰的作用,并引起箱内外气体交换速率和散热状况变化,从而出现不同的燃烧现象。对(?)极大值的变化特点作了讨论。     

风斗进气冷却效果随飞行高度变化规律研究

针对飞机飞行高度增加时风斗进气冷却效果的变化规律这一问题,本文采用数值模拟和试验相结合的方法进行研究。结果发现,在发动机状态相同时,短舱内各测点温度随飞行高度的增加而增加,表明了飞行高度增加,风斗进气的冷却效果会变差。     

Detection of methane plumes in the water column of Logatchev hydrothermal vent field,Mid-Atlantic Ridge

During DY105-17 cruise onboard the R/V "Da Yang Yi Hao" in 2005,methane concentrations in the wa-ter column above Logachev hydrothermal vent field were measured by applying stripping/trapping-gas chromatographic (GC) and the distinct methane plumes were detected. Results show that the back-ground methane concentration within the Logachev area is from 1.05 nmol/L to 1.68 nmol/L,signifi-cantly higher than the background level of the Atlantic abyssal plain of 0.4―0.5 nmol/L,suggesting that hydrothermal venting is a major source of dissolved methane to the ocean. The highest anomalies of methane concentrations in the water column range from 7.14 nmol/L to 113.9 nmol/L and occur just at 180―500 m above the seafloor. The distribution of methane concentration and the structural charac-teristics of hydrothermal plumes are strongly influenced by the supply of underlying hydrothermal fluids,the mixing process of ocean bottom currents and the microbial oxidation. Furthermore,the dif-ferences in distribution of methane plume between the station MAR-CTD3 and the other stations indi-cate a probable unknown hydrothermal vent site nearby. There occurs high concentration of methane along with temperature and nephelometry anomalies,which strongly confirms that the subtle meas-urement of methane concentration in water column is one of the effective ways to locate active sites of hydrothermal venting.     

运动会管理系统的设计和实现

说明运动会管理系统的构思和方法 ,详细介绍了解决该系统中二个关键问题的编程思路和技巧     

水电站变顶高尾水洞瞬变流计算及体型设计

对水电站变顶高尾水洞内明满交替流计算方法及变顶高尾水洞体型设计进行了研究，介绍了变顶高尾水洞的工作特点．采用改进狭缝法模型，结合某大型水电站取消尾水调压室方案进行瞬变流计算，提出了明满交替流分界点的处理方法．分别针对具有不同顶坡、底坡和底宽的变顶高尾水洞体型在不利工况下的瞬变流计算成果进行比较分析，结果表明，变顶高尾水洞具有一定的尾水调压室作用，若适当地选取体型参数可不设尾水调压室；顶坡对整个尾水系统的影响非常大，底坡和底宽的影响相对较小．