安全壳钢衬的初始后屈曲分析

基于Ｄｏｎｎｅｌｌ的非线性板壳理论，认为钢衬壳是一种有特殊缺陷形状的钢衬板，用初始后屈曲渐进分析理论，研究了在温度应力作用下缺陷钢衬板即钢衬壳的初始后屈曲性态。计算了一个四点铆固钢衬壳模型，同时给出了铆钉间距等参数对钢衬壳屈曲极值温度的影响。     

铜及铜合金中铜量分析方法综述

现行标准ＧＢ５２３１－ＧＢ５２３５－８５中共有８８个合金牌号要求测定铜量，其含铜量从５３％到９９．９７％以上。本文就ＩＳＯ、ＧＢ和主要铜材生产企业分析规程中铜量测定方法，结合本人的实践经验进行综述。     

激光微区光谱定量分析及其在激光晶体研究与检验中之应用

本文概括介绍了激光微区光谱定量分析激光晶体中掺元素浓度的研究成果，着重讨论了定量分析中的几个主要问题。     

快中子零功率反应堆(DF-VI)的临界事故概率分析

本文应用故障树分析方法,对快中子零功率堆(DF-Ⅵ)在启动过程中发生临界事故的可能性做了初步的定量估计。结果表明,该堆每次启动发生临界事故的概率约为10~(-6)量级,得出确保装置启动安全的首要因素是选配合格的操作人员的结论,并对设备的改进提出了一些建议.     

On-Line File Caching

Abstract. Consider the following file caching problem: in response to a sequence of requests for files, where each file has a specified size and retrieval cost , maintain a cache of files of total size at most some specified k so as to minimize the total retrieval cost. Specifically, when a requested file is not in the cache, bring it into the cache and pay the retrieval cost, and remove other files from the cache so that the total size of files remaining in the cache is at most k . This problem generalizes previous paging and caching problems by allowing objects of arbitrary size and cost, both important attributes when caching files for world-wide-web browsers, servers, and proxies. We give a simple deterministic on-line algorithm that generalizes many well-known paging and weighted-caching strategies, including least-recently-used, first-in-first-out, flush-when-full, and the balance algorithm. On any request sequence, the total cost incurred by the algorithm is at most k/(k-h+1) times the minimum possible using a cache of size h ≤ k . For any algorithm satisfying the latter bound, we show it is also the case that for most choices of k , the retrieval cost is either insignificant or at most a constant (independent of k ) times the optimum. This helps explain why competitive ratios of many on-line paging algorithms have been typically observed to be constant in practice.     

舰船用断路器抗冲击欠压脱扣器的设计

对断路器的欠压脱扣器结构进行分析和研究 ,采用平衡机构、弹性球效应等抗冲击设计方法 ,并通过理论计算和验证 ,将H—DW14舰船用断路器的欠压脱扣器设计成具有抗冲击能力的产品 ,以适应舰船的要求。     

PVA平均聚合度波动因素分析及优化控制

针对聚乙烯醇 (PVA)聚合反应过程中 ,平均聚合度波动的实际问题 ,在对聚合反应工艺、反应机理进行理论分析的基础上 ,找出了影响平均聚合度波动的主要因素 ,并逐一分析了对平均聚合度影响的情况 ,在理论和实验基础上找出了在多品种PVA生产中各主要因素变化对平均聚合度变化的规律 ,提出了包括运用先进仪表控制手段在内的优化控制措施和处理办法     

A method for quantifying cell size from differential interference contrast images: validation and application to osmotically stressed chondrocytes

An automatic image analysis method was developed to determine the shape and size of spheroidal cells from a time series of differential interference contrast (DIC) images. The program incorporates an edge detection algorithm and dynamic programming for edge linking. To assess the accuracy and working range of the method, results from DIC images of different focal planes and resolutions were compared to confocal images in which the cell membrane was fluorescently labelled. The results indicate that a 1‐µm focal drift from the in‐focus plane can lead to an overestimation of cell volume up to 14.1%, mostly due to shadowing effects of DIC microscopy. DIC images allow for accurate measurements when the focal plane lies in a zone slightly above the centre of a spherical cell. In this range the method performs with 1.9% overall volume error without taking into account the error introduced by the representation of the cell as a sphere. As a test case, the method was applied to quantify volume changes due to acute changes of osmotic stress.     

曙—区超稠油间歇蒸汽吞吐技术探讨

针对曙-区超稠油井进入高周期后产量递减，成本上升的矛盾，提出用间歇吞吐技术改善高周期蒸汽吞吐效果，通过对吞吐机理和现场实际资料统计的分析。对这项技术实施的条件及效果进行了探讨。结果表明，该项技术在高周期井实施效果较好。具有较好的推广前景。     

井眼剪切带分叉研究

井眼基本破坏形式是由于不稳定性造成的井眼岩石崩落坍塌和剪切带。井眼破坏的非均匀性采用传统的理论和方法不能得到较好的解释和预测。采用材料的分叉分析方法和变形局部化的数值模拟研究 ,可望对井眼失效的机理分析、预测和控制提供新的思路