载人航天中的防火安全与微重力燃烧研究

简要阐述了载人航天器防火安全的重要性、面临的问题及解决途径。介绍了防火安全措施。对载人航天任务中所涉及的微重力燃烧研究的领域、特点及途径予以讨论。     

原位统计分布分析在焊接结构用大壁厚钢铸件应用性能评价中的应用

大壁厚钢铸件广泛应用于超大型焊接工程结构中,提高大壁厚钢铸件的冶金质量是确保结构安全的重要保证。为加强今后大壁厚钢铸件生产过程中的冶金质量控制,采用金属原位统计分布分析技术和热模拟技术对边长为1000mm的方形铸件进行元素分布测定及热模拟试验,并对铸件的力学性能、金相组织进行了分析,以进行使用性能评价研究。发现距离表面110mm附近存在偏析带,C、Mn、Si、P均有不同程度的富集,而含Al夹杂物较少。铸件四分之一厚度处存在明显的负偏析区。铸件心部则存在较明显的中心疏松和正偏析,同时也存在主要含Al、Ti等元素的夹杂物富集。试验结果表明溶质元素C偏析造成了铸件在不同位置连续转变曲线和拉伸性能的明显差异,并会对焊接性造成影响。金属原位统计分布分析技术可以全面反映铸件的元素偏析情况,从而更有针对性地做好质量控制措施。     

保护"接地"和"接零"应用中几个应注意问题

介绍了保护“接地”和保护“接零”的适用场合、特性及注意问题,并分析了其错误原因。     

稠油热采蒸汽等干度分配技术

锅炉蒸汽等干度分配是基于相分离原理进行工作的,即分配到支路管线的两相流体由相分离后的2股流体组合而成,其中一股流体的干度较高,另一股流体的干度则较低.通过调节2股流体的比例实现流量分配和干度控制.在等干度分配中,该分配技术既适合于2条支路的分配,也适合任意多支线的分配;既可以实现等流量、等干度分配,也可以实现不同流量时的等干度分配.     

从成藏演化论稠油形成机理--以济阳坳陷罗家地区为例

通过对沉积埋藏史、生烃史及油气运聚史的研究,确定烃源岩生、排烃及油气运聚期次;结合稠油物理、地球化学性质复杂变化的特点,以阶段性成藏各过程为线索,分析各阶段稠油形成的主要控制因素,理清了稠油的形成机制,建立了石油稠化模式,总结了石油的分布规律;提出了“多种烃源岩、多个成藏期及多种石油稠化作用控制重油成因与分布”的新观点,拓宽了研究重油成因与分布的新思路。     

"一注多采"技术在辽河油田超稠油油藏中的应用

“一注多采”技术在杜84断块的应用,改善了生产效果,提高了经济效益。“一注多采”方式的提出对于解决超稠油中、后期开发矛盾具有重要的现实意义。     

Bayesian spatial and ecological models for small-area accident and injury analysis

In this article, recently developed Bayesian spatial and ecological regression models are applied to analyse small-area variation in accident and injury. This study serves to demonstrate how Bayesian modelling techniques can be implemented to assess potential risk factors measured at group (e.g. area) level. Presented here is a unified modelling framework that enables thorough investigations into associations between injury rates and regional characteristics, residual variation and spatial autocorrelation. Using hospital separation data for 83 local health areas in British Columbia (BC), Canada, in 1990–1999, we explore and examine ecological/contextual determinants of motor vehicle accident injury (MVAI) among male children and youth aged 0–24 and for those of six age groups (<1, 1–4, 5–9, 10–14, 15–19 and 20–24). Eighteen local health area characteristics are studied. They include a broad spectrum of socio-economic indicators, residential environment indicators (roads and parks), medical services availability and utilisation, population health, proportion of recent immigrants, crime rates, rates of speeding charge and rates of seatbelt violation. Our study indicates a large regional variation in MVAI in males aged 0–24 in British Columbia, Canada, in 1990–1999, and that adjusting for appropriate risk factors eliminates nearly all the variation observed. Socio-economic influence on MVAI was profoundly apparent in young males of all ages with the injury being more common in communities of lower socio-economic status. High adult male crime rates were significantly associated with high injury rates of boys aged 1–14. Seatbelt violations and excess speeding charges were found to be positively associated with the injury rates of young men aged 20–24. This and similar ecological studies shed light on reasons for regional variations in accident occurrence as well as in the resulting injuries and hospital utilisation. Thereby they are potentially useful in identifying priority areas for injury/accident prevention and in informing regional health planning and policy development.     

大型拱顶储罐和内浮顶罐顶盖形式及用材探讨

短程线形网壳结构已成功用于大型储罐顶盖,该结构受力合理、可工厂化制造、安装方便、省时省料、经济性好。文章对钢制网壳结构与铝合金制网壳结构进行对比分析后认为,铝合金网壳经济性更好,值得推广。但铝网壳结构在油罐上使用涉及雷电安全等诸多问题,致使这种结构一时又难以推广。     

大型稠油油藏整体数值模拟方法

文章介绍了NUMSIP模型软件的分块计算和区域分解并行计算功能,提供了一套大型整装油藏整体注蒸汽热采数值模拟的方法,包括整理数据、建立模型、拟合代表块确定基础参数、分块计算和整体并行计算等过程。并用该方法研究欢喜岭油田齐40块莲Ⅱ油藏剩余油分布。研究表明,利用NUMSIP模拟软件进行大型整装油藏整体注蒸汽热采模拟的方法已基本成熟,利用该方法可以通过拟合整个油藏的动态历史来获得当前剩余油分布,并且可信度高、费用相对较低,为剩余油的研究开辟了新的途径,对指导生产具有实际意义。     

Long-term effects of legislation and local promotion of child restraint use in motor vehicles in Sweden

The main objective is to study long-term effects of legislation and promotion of child-restraint use in motor vehicles. Subgoals are to describe the level of restraint use in cars and changes in mortality and morbidity patterns in regard to differences among age groups and geographical areas (morbidity). The study areas were; ‘The First Four’, ‘The Six Counties’, ‘The Rest of Sweden’, and ‘Sweden as a whole’, and the population were two age groups — 0–6 and 7–14 years. The incidence of restraint use comes from observations of car-seat-belt usage. Outcome evaluation was based on hospital-discharge data 1978–1996 and mortality statistics 1970–1996. The level of restraint use for children in the front seat was 97% in 1988 and was equal to 1995. Mortality data shows a decrease of 2.8% on an average per year, 76% over the study period. A significant change over time in the two intervention areas was shown (annual changes of −2.8 and −1.8%), but not in the rest of Sweden. The local authorities that started early with preventive programs, such as safety seat loan schemes and those having an organised safety-promotion program showed a much better improvement than the rest of Sweden. There is a need for appropriate information for local action on childhood injury prevention to accompany national legislation.