氧化镁膨胀剂对船闸施工期混凝土开裂风险的影响

针对船闸大体积、异型结构混凝土的施工期开裂问题,依托九圩港二线船闸工程,模拟评估氧化镁膨胀剂及外保温措施对结构混凝土温度场、应力场和开裂风险的影响,并通过对实体结构温度、变形的监测,评估实际工程应用效果。结果表明,在混凝土中掺加氧化镁膨胀剂是降低船闸结构混凝土施工期收缩开裂的有效措施之一,在冬季较低的浇筑温度下,掺加氧化镁膨胀剂并配合一定保温措施,可同时降低混凝土结构表面和中心的开裂风险。氧化镁膨胀剂的掺入基本不会影响船闸混凝土的温度历程,但能够降低闸室边墙结构混凝土温降阶段的收缩50×10~(-6)~70×10(-6),降低闸首廊道结构混凝土温降阶段收缩40×10~(-6)以上,显著提升船闸混凝土施工期抗裂性。     

Incremental Supervised Subspace Learning for Face Recognition

Subspace learning algorithms have been well studied in face recognition. Among them, linear discriminant analysis (LDA) is one of the most widely used supervised subspace learning method. Due to the difficulty of designing an incremental solution of the eigen decomposition on the product of matrices, there is little work for computing LDA incrementally. To avoid this limitation, an incremental supervised subspace learning (ISSL) algorithm was proposed, which incrementally learns an adaptive subspace by optimizing the maximum margin criterion (MMC). With the dynamically added face images, ISSL can effectively constrain the computational cost. Feasibility of the new algorithm has been successfully tested on different face data sets.     

朱家尖月岙渔港透空式防波堤设计

透空式防波堤由于具有透流性好、地质条件适应性好、造价较低、施工方便、环境影响小等优点使其应用前景广阔。但由于其结构形式较新,对其研究、应用相对较晚,相关规范对其仅有较少规定,不足以很好地指导透空式防波堤的设计过程。在参考国内外研究成果、现行规范及类似工程经验的基础上,系统地给出了透空式防波堤的设计过程。根据详尽的基础资料和使用功能,设计了朱家尖月岙渔港防波堤结构。在结构设计过程中采用了“先计算初定,后试验优选”的设计方法。物理模型试验结果表明,结构水平力估算方法是合理的。对于情况相似的透空式防波堤工程设计,具有较好的参考价值。     

吉林省全面开展公路安全保障工程的实施工作

2004年吉林省在全省范围内组织实施以“消除隐患，珍视生命”为主题的公路安全保障工程，对全省国省干线、重点旅游路线、县级公路等公路交通安全状况进行了全面排查和治理。本文阐述了安保工程实施原则及一些新技术、新材料、新工艺、新思路。     

公路导线点的布置和观测成果计算中的注意事项

高等级公路建设中5^#导线点的布设和计算成果对设计和施工起着非常重要的作用，本文主要介绍了5^#导线点的布置和观测成果计算中的注意事项。     

导弹中末段制导导引律转换研究

文章研究了导弹由中间段制导律向末段制导律转换的问题,提出了一种可变导引系数的组合制导律,即可变系数组合比例导引律（ACNG）。仿真结果表明,该导引律总体优于纯比例导引和固定系数组合比例导引律,中末段弹道过渡平滑,衔接良好,有利于中末段的交班,同时降低了导弹的需用过载。     

内河大型浅吃水滚装船艉型优化

内河船舶吃水受到限制,改善船舶艉部线型,提高螺旋桨效率,文中根据长江大型滚装船设计过程中,通过理论分析及船模试验的结果,比较了双机双桨、三机三桨以及双艉、涡艉等不同船型带来的航速收益。     

快乐车迷

从小因为家离学校太远,就与车结下了不解之缘,不过那时骑的还是自行车,直到1997年8月,大哥才将一辆红色的五羊-本田WY125A(进机)推回了家中。当时我也不大在意,因为那铁家伙跟自行车比太重了,但每次坐在大哥身后与风同行时,我都不能自己。顺理成章,我不久就学会了骑车,我开始关注与摩托车有关的一切。2000年开始,我     

Mean shift registration algorithm for dissimilar sensors

The mean shift registration (MSR) algorithm is proposed to accurately estimate the biases for multiple dissimilar sensors. The new algorithm is a batch optimization procedure. The maximum likelihood estimator is used to estimate the target states, and then the mean shift algorithm is implemented to estimate the sensor biases. Monte Carlo simulations show that the MSR algorithm has significant improvement in performance with reducing the standard deviation and mean of sensor biased estimation error compared with the maximum likelihood registration algorithm. The quantitative analysis and the qualitative analysis show that the MSR algorithm has less computation than the maximum likelihood registration method.     

Review on composite structural health monitoring based on fiber Bragg grating sensing principle

Fiber Bragg grating (FBG) based sensors offer important advantages over traditional instrumentation with regards to real-time structural health monitoring (SHM) of composite materials and structures in recent years. FBG sensors, integrated into existing structures or embedded into new ones, have played a major role in assessing the safety and integrity of engineering structures. In this paper, a review on the latest research of the FBG-based SHM technique for composite field is presented. Firstly, the FBG sensing principle is briefly discussed and FBG and several other optical fiber sensors (OFSs) for SHM are performance-compared. Then, several examples of the use of FBG sensors in composite SHM are illustrated, including those from the field of cure monitoring, civil engineering, aviation, aerospace, marine and offshore platform. Finally, some existing problems are pointed out and some proposals for further researches are provided.