浅谈如何在工程变更中分析合同条款强化变更管理

针对H航市政工程仔细研究合同,找准突破口,把变更方向确定为通过各类措施增加土方工程量和尽量争取合同内专业分包转为项目部实施为目标。     

双参数地基上土钉墙面层土压力计算

土钉墙面层承受部分土(水)压力,文中把土钉墙面层看作是弹性地基上的有限长梁,在试验的基础上,推导了基于双参数地基的成层土层分布的土钉墙面层在土钉拉力作用下的挠曲线、转角、弯矩和剪力方程,并与实测数据进行了比较分析,验证了模型的合理性,得到的解析解基本上可以反映土钉墙面层土压力的分布.在此基础上,探讨了不同土性土层中土钉墙面层土压力的分布.面层土压力在土层的分界面上位移连续土压力突变;作用在软弱土层的面层土压力比硬土层上的面层土压力大;上软下硬型较上硬下软的土层分布更能使面层土压力得到充分发挥;同时文中计算了面层土压力换算成荷载与土钉拉力的比值,面层对于土压力的作用随着深度的增加表现得愈加明显,提出针对不同地区不同深度和不同土性条件下应给出比值的建议值,以使土钉墙的设计更符合其真实的作用机理.文中得到的结论和计算方法对于进一步研究土钉墙的作用机理及设计中如何充分发挥面层的作用等具有重要的理论意义和实际应用价值.     

水土计算原则及浅埋结构土压力计算理论分析

基于现有规范、理论和工程经验,对地下结构中的水土计算原则和浅深埋界限的确定方法进行了归纳分析,给出了浅埋地下结构竖向土压力计算的3种理论,即土柱理论、比尔鲍曼理论和谢家理论,并对三个理论在规范计算方法中的应用进行了深入讨论,系统给出了浅埋地下结构土层压力计算方法。     

Civil 3D与Google Earth在工程方案中的应用

文章通过对某排土场方案设计,介绍了Civil3D与Google Earth在工程方案中的应用,利用Civil 3d从Google Earth中导出地形,并进行三维设计及仿真处理。     

Four case studies,six years later: Developing system thinking skills in junior high school and sustaining them over time

This study examines the process by which system thinking perceptions develop within the context of a water cycle curriculum. Four junior high school students undergoing an especially designed inquiry‐based intervention were closely observed before, during, immediately after, and 6 years after completing a year long systems‐based learning program. The employed research tools included observations, semi‐structured interviews, and a number of “concept viewing” tools (drawings, concept maps, and repertory grids). Out of the data, four distinct “stories,” each presenting a different way of constructing hydro system mental models, are described. The paper's main conclusion is that students develop their systems mental models and remember the learned material based on learning patterns that tend to remain unchanged over time. Consequently, in order to facilitate efficient and lasting construction of students' system models, learning experiences should harness these, and especially the meta‐cognitive learning pattern, which holds special significance for constructing systems. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 1253–1280, 2010     

元数据信息在地球科学数据导航系统中的应用

目前，元数据的研究和应用越来越受到重视，我们在自己所建信息平台基础之上，利用网络地球科学数据资源已经公布的元数据信息，根据地球科学数据元数据信息的内容和特点，确定了地球科学数据导航系统的元数据元素项目内容，经过多重的扩展和定义以及选择利用，有效地实现了对这部分信息的系统揭示，体现了较完整的导航功能。本文就作者2年多来利用元数据在地球科学数据导航系统中的实践应用谈一点体会和认识。     

Self-assembly-induced luminescence of Eu3+-complexes and application in bioimaging

Design and engineering of highly efficient emitting materials with assembly-induced luminescence, such as room-temperature phosphorescence (RTP) and aggregation-induced emission (AIE), have stimulated extensive efforts. Here, we propose a new strategy to obtain size-controlled Eu³⁺-complex nanoparticles (Eu-NPs) with self-assembly-induced luminescence (SAIL) characteristics without encapsulation or hybridization. Compared with previous RTP or AIE materials, the SAIL phenomena of increased luminescence intensity and lifetime in aqueous solution for the proposed Eu-NPs are due to the combined effect of self-assembly in confining the molecular motion and shielding the water quenching. As proof of concept, we also show that this system can be further applied in bioimaging, temperature measurement and HClO sensing. The SAIL activity of the rare-earth (RE) system proposed here offers a further step forward on the roadmap for the development of RE light conversion systems and their integration in bioimaging and therapy applications.     

山区房屋背面兼作挡土墙的典型设计——三明市×办公楼工程实录

简要叙述陡坡地段挡土墙和建筑后墙合一的结构形式与技术经济效果,旨在对建筑场地紧缺的我省山区建筑工程予以推广。     

稀土与叶绿素作用关系的研究进展

本文从稀土对叶绿素形成的促进作用、对叶绿体结构的影响、体外稀土叶绿素的合成和结构表征、天然植物叶片稀土叶绿素的发现和结构表征、人工培养菠菜体内稀土叶绿素的形成和结构表征等方面综述了稀土元素与叶绿素作用关系的研究成果.     

走向大协调化生存方式（之二）——在全球宏观协调中实现全人类的健康长寿

宇宙大尺度运动交叉协调的一个重要成果及标志,就是构成了适宜生物生存的环境。可是,现代人类盲目的规模巨大的活动严重破坏了构成适宜人类生存环境的交叉协调机制和人类健康生存的大协调机能。各门相关学科已经在反思人类盲目活动的教训中,陆续认识到人类可持续健康生存应该遵循的一些协调规律。必须运用大协调学把这些知识衔接起来,进一步周全地探讨人类同自然与社会各方面大尺度交叉协调规律,应用于改善人类的婚育、饮食、活动方式等各方面和生活用品设计与检测,从根本上提高人类的生存质量。