黄浦江下游吴淞口站低潮位重现期研究

黄浦江为感潮河流,低潮位重现期的确定对黄浦江航道的设计具有重要意义。为了准确估计黄浦江低潮位的重现期,以黄浦江下游吴淞口站年最低潮位序列为例,在对样本进行三性审查的基础上,分别采用传统的数理统计方法和时变矩方法进行水文频率分析。结果表明:吴淞口站年最低潮位序列在1996年发生了变异;还现修正后的序列服从位置参数线性时变的GEV模型,低潮位存在缓慢的上升趋势;一致性条件下百年一遇低潮位约为0.261 m,在非一致性条件下其重现期增大为150 a。非一致性条件下的重现期增大说明黄浦江现有的航道设计标准偏安全,航道通航保证率提高。     

单向实时数字视频传输中帧同步锁定技术研究

提出一种适用于单向实时数字视频传输系统的帧同步锁定方案。其方法在接收端采用本地参考时钟、状态机、锁相环，并结合CIMT编码方式实现系统自动维持帧同步锁定，而无需周期性加入帧同步码。对该帧同步锁定方案与周期性加入帧同步码强制锁定方案进行性能比较．并将其应用到单向实时数字视频光纤传输系统中。实验证明，系统自动实现帧同步锁定的方案是单向实时数字视频传输系统实现帧同步锁定的最佳方案。     

永定新河河口潮流动力及泥沙特征初步分析

依据永定新河河口１９９７年潮汐观测资料及河道１９９０～１９９７年潮汐观测资料，通过实测资料的整理分析，初步揭示了永定新河河口潮流动力及泥沙特征，为河道的治理规划提供了科学的依据。     

A direct stiffness analysis of a composite beam with partial interaction

The use of the conventional semi-analytical stiffness method in finite element analysis, in which interpolation polynomials are used to develop the stiffness relationships, leads to problems of curvature locking when beam-type elements are developed for composite members with partial interaction between the materials of which it is comprised. The curvature locking phenomenon that occurs for composite steel–concrete members is quite well reported, and the general approach to minimizing the undesirable ramifications of curvature locking has been to use higher-order polynomials with increasing numbers of internal nodes. This paper presents an alternate formulation based on a direct stiffness approach rather than starting from pre-defined interpolation polynomials, and which does not possess the undesirable locking characteristics. The formulation is based on a more general approach for a bi-material composite flexural member, whose constituent materials are joined by elastic shear connection so as to provide partial interaction. The stiffness relationships are derived, and these are applied to a simply supported and a continuous steel–concrete composite beam to demonstrate the efficacy of the method, and in particular its ability to model accurately both very flexible and very stiff shear connection that causes difficulties when implemented in competitive semi-analytical algorithms. Copyright © 2004 John Wiley & Sons, Ltd.     

An eight‐node hybrid‐stress solid‐shell element for geometric non‐linear analysis of elastic shells

This paper presents eight‐node solid‐shell elements for geometric non‐linear analysis of elastic shells. To subdue shear, trapezoidal and thickness locking, the assumed natural strain method and an ad hoc modified generalized laminate stiffness matrix are employed. A selectively reduced integrated element is formulated with its membrane and bending shear strain components taken to be constant and equal to the ones evaluated at the element centroid. With the generalized stresses arising from the modified generalized laminate stiffness matrix assumed to be independent from the ones obtained from the displacement, an extended Hellinger–Reissner functional can be derived. By choosing the assumed generalized stresses similar to the assumed stresses of a previous solid element, a hybrid‐stress solid‐shell element is formulated. Commonly employed geometric non‐linear homogeneous and laminated shell problems are attempted and our results are close to those of other state‐of‐the‐art elements. Moreover, the hybrid‐stress element converges more readily than the selectively reduced integrated element in all benchmark problems. Copyright © 2002 John Wiley & Sons, Ltd.     

信集闭系统进路数学模型及进路连锁表生成判据的研究

本文对信集闻系统中的长进路，进路及进路间的敌对关系等重要概念作了精确定义，并提出了进路的数学模型以及进路连锁表的生成判据。     

灌河潮流界位置确定与港口防淤探讨

盐城市位于江苏省中部,地处黄海之滨,承接里下河腹部区的排水,区内入海河流众多,在这些入海河流上大多建有挡潮闸坝。但由于盐城市近海为淤积型海岸,闸坝的建设改变了河口的自然状态,造成港口下游淤积严重,排水不畅。灌河作为江苏省沿海唯一下游没有建挡潮闸的重要入海河流,仍为自然状态,下游港口未淤积。本文通过对灌河水体涨、落潮中氯离子含量的监测,找出海水上溯的最大距离,确定其影响范围,为其它入海流河流的防淤提供借鉴。     

CO2激光器线偏振光输出腔内起偏器的研究

混合InGaAs光电二极管阵列ETX128FPA是16384元InGaAs焦平面阵列,供1.0～1.7μm波段内的近红外成象使用。这种128×128元的二维光电二极管阵列是使用钢冲击结合技术把InGaAs材料结合到高级的CMOS倍增管上而制成的。     

安居水电厂灯泡贯流式水轮发电机组的试运行

本文对安居水电厂2台灯泡贯流式水轮发电机组自投入试运行以来,出现的受油器壳体开裂、导叶接力器缸体和活塞拉伤、转轮桨叶传动拐臂连接销脱落、导叶外轴承座漏水、主轴工作密封漏水侵入水导轴承、锁锭装置固定螺钉剪断等故障的经过、原因分析及其处理办法进行了叙述。     

河口海岸水文信息处理系统

应用Visual Basic6.0应用程序、Microsoft Access数据库和FORTRAN语言开发的河口海岸水文信息处理系统，具有水文现场资料整编功能、利用分潮优化技术的潮汐调和分析及预报功能，且计算工作量相对较小，预报精度高。