一类盾构管片接头破坏历程的解析解

为研究一类采用斜直螺栓、不设传力衬垫构造形式的盾构管片接头在高荷载水平下的破坏力学性态,在引入一定假设基础上,提出了可用于分析管片接头破坏历程的简化解析模型,并对简化模型在线性转动、接头张开、接头屈服等不同阶段的接头截面应力分布和转动情况进行了分析和推导。并通过弯矩-转角关系曲线和接头极限弯矩两个方面对本文简化力学模型的解析解与管片接头足尺试验结果进行了比较和验证,比较结果表明,该方法所得结果与试验结果基本一致,是可行的。     

从Y古1潜山落空看潜山与砂砾岩扇体对应关系

Y古1潜山在三维地震剖面上潜山形态完整，但实钻结果显示前震旦系界面深度与地震剖面潜山界面反射深度相差较大，该文针对Y古1井构造落空的主要原因进行了讨论。通过与郑家潜山对比分析，提出潜山形态不落实是其主要原因并且与该潜山上覆厚达几百米的砾岩盖层有关，与通常的沟扇对应理论不符。在今后的勘探中，应用地震资料针对潜山上覆砾岩反射速度的问题，如能变速成图，则会在一定程度上减少勘探的盲目性。     

甲基乙烯基硅橡胶的化学交联及溶胶与凝胶分布的研究EI

研究了二甲基及乙烯基含量不同的甲基乙烯基硅橡胶的化学法交联的凝胶生成动力学及凝胶溶胶分配关系。在化学法交联过程中,溶胶平均分子量及单位交联剂量的交联度均是交联剂量的减函数。从溶胶与凝胶分配关系可知,二甲基硅橡胶的交联为无规过程,ln((1-S)/S]～Ⅰβ为线性关系,而甲基乙烯基硅橡胶的交联不能以无规过程来描述,ln[(1-S)/S]～Ⅰβ为非线性关系。     

加工曲轴用车拉刀的设计

介绍了加工曲轴用车拉刀的结构原理和设计、加工要点。     

软段对氨基磺酸盐型高固含量聚氨酯分散体性能的影响

以N-(2-氨基乙基)-2-氨基乙烷磺酸钠(AAS-Na)为亲水单体,以不同结构的多元醇、异佛尔酮二异氰酸酯(IPDI)、六亚甲基二异氰酸酯(HDI)和乙二胺(EDA)等为原料,采用丙酮法合成了固含量为50%的磺酸盐基聚氨酯分散体(PUD)。研究结果表明:PUD的ζ电位均低于-30mV,平均粒径在230～290nm之间,黏度均低于800mPa·s,呈现假塑性流体的特征;PUD胶膜的吸水率均低于10%,具有良好的耐水性能;PUD胶膜的结晶行为和力学性能受软段影响较大,起始分解温度为275℃,具有良好的热稳定性,能满足一般场合的使用要求。     

激光阈值法测量磷酸盐钕玻璃片中心波长的研究

利用激光阈值法对两种应用于高功率固体激光片状放大器中的磷酸盐激光玻璃的中心波长进行了实验测试。实验结果表明,国产新型N31磷酸盐激光玻璃的中心波长为1052.7nm,俄罗斯进口某型号磷酸盐激光玻璃的中心波长为1051.4nm。     

A Novel Dynamic Fault Restoration Mechanism Using a Multiple Ring Approach in WDM Mesh Networks

This work describes a distributed fault restoration algorithm, called the Dynamic Multiple Ring Algorithm (DMRA), for application in WDM mesh networks. This study explores the choice of restoration paths and the assignment of fault-tolerant bandwidth when a link, node, or channel failure occurs according to the change in traffic load, number of nodes, and transmission delay including propagation and switching delays. Accordingly, the primary aim of this work is to use networking segments near faults to share the restoration load throughout a mesh network. Each node searches for restoration paths in their near environment using the proposed DMRA. Nodes use distributed control to search for neighboring nodes and to establish the relationship between them to build numerous logical rings. Nodes can also locate faults in the logical rings. These rings establish the restoration paths. The traffic load over failed links or nodes can be diverted to other paths in the networking segments. The cost of the restoration paths is computed at each node based on both the current capacity and the transmission delay. The selected restoration paths are suitable transmission routes in the network neighborhood. Hence, restoration paths can be identified and wavelength assigned quickly according to network bandwidth and traffic load. Simulation results reveal that the proposed method works extremely quickly and has a high success rate. Consequently, it is very useful for applications in real WDM networks, where the status varies from minute to minute.Corresponding author is presently a guest scientist with the National Institute of Standards and Technology, USA. This research was partially supported by the Grant of National Science Council, ROC (NSC-92-2218-E-155-004 and NSC-93-2917-I-155-001).     

从黑白图像中检测圆

提出了一种基于线条化边界线的圆检测算法。先从灰度图像中确定宽度为1的边界线，再把边界线分成N个片段，找到所有合适的圆心及半径，逐步求精地确定圆的最终位置。算法的复杂度为0(N^3)。     

Preparation and characterization of star polymers with polyurethane cores using polycaprolactone triol

Star‐shaped polymers with two different core sizes were prepared by step polymerization. Their structures were confirmed by FTIR and ¹H NMR studies. X‐ray diffraction studies showed highly crystallized patterns for this type of star polymer. Thermogravimetric analysis curves displayed an excellent thermal stability and a two‐step degradation mechanism for these materials. In addition, it indicated that if the length of the triol segment were longer, the degradation temperature at 10% weight loss would be higher. © 2002 Society of Chemical Industry     

复杂介质的折射波射线追踪

本文由二维层状介质模型出发论述了折射波逐段迭代射线追踪的原理，由于连接炮点和接收点之间的初始射线路径满足费马原理，因此其上任意连续三点之间的射线路径也满足费马原理。据此即可分别推导出透射中间点和折射点的一阶修正公式，进行折射线逐段迭代计算求出整条射线路径。将此原理推广到二维块状介质模型，用于解决复杂介质中的折射波射线追踪，推导出任意界面上折射点的一阶显式增量修正公式。避免了高次多元方程的求解，具有计算速度快，能够适用任意界面的特点。文中还指出了在块状介质模型中用逐段迭代法进行射线追踪较在层状介质中难度大的原因在于射线路径点的增、删。实例试算表明。文中所述方法是一种有效的折射波射线追踪方法。