建筑工程中现浇板裂缝原因及防治措施

针对现浇钢筋混凝土板普遍存在的裂缝现象，从设计和施工两方面综合分析了裂缝产生的原因，提出了有效克服裂缝的预防和处理方法，以供同行参考。     

连拱隧道施工技术初探

随着国家环保措施的逐步加强和完善,隧道工程在公路、铁路建设中所占比例越来越高。大跨度隧道施工难度较大,连拱隧道施工相对安全、结构美观以及相对同等地质条件下的分离式隧道而言具有占地少、投资小等优点。受传统施工方法的制约,连拱隧道多以短隧为主。结合某连拱隧道施工经验,浅谈对连拱隧道施工方法的见解和对连拱隧道质量通病的控制及预防。     

“新江南水乡”之设计构想——朱家角环大淀湖景观规划

介绍朱家角环大淀湖的景观规划;思索“新江南水乡”景观空间模式和特点,并具体分析现代景观空间对“原汁原味”的本土文化新的表达方式。     

如何做好混凝土原材料的质量控制

原材料质量的好坏是影响混凝土质量的关键因素。本文从水泥、掺合料、细骨料、粗骨料、外加剂等方面浅谈了如何做好混凝土原材料质量的控制问题。     

基于SVM和能量最小化的PolSAR图像分类方法

极化合成孔径雷达(PolSAR)采用全极化的工作方式可以获取地物的多种特征,利用这些特征对地物进行分类是PolSAR图像的重要应用方向。不同的特征和分类器对分类精度有着较大的影响。提出了一种基于支持向量机(SVM)和能量最小化(EM)的极化SAR图像地物分类方法。该方法选择基于6种散射模型的分解方法(6SD)所得的6部分散射能量、总散射能量span和3个极化相干矩阵旋转域角参数作为SVM的输入,得到图像分类结果,并使用基于图割的能量最小化算法α-expansion对分类结果进行优化。最后使用AIRSAR系统获得的Flevoland地区的数据进行实验,结果表明所提算法可以提高总体分类精度,总体分类精度为95.6%,高于其他方法的92.3%。所提算法可以较大幅度地提高散射机理明显的区域,如建筑、森林、水域、草地等区域的分类精度。另外,结合EM优化结果可以提高所有种类的分类精度,其中在苜蓿、小麦1、小麦2、裸地、草地、油菜籽等区域的分类精度可提高1%以上。     

明代泉州海防卫所的军事聚落形态探究——以金门所城和崇武所城的比较为例

通过对比分析明代金门所城和崇武所城在选址布局、空间形态和城墙构造等方面的异同,探寻二者的共性和特殊性,从而更加深刻地揭示明代泉州海防卫所军事聚落的建制体系、布局特征和形制特色,也为金门所城的修复考证提供借鉴。     

超高层建筑室内外园林工程施工的难点与创新——以上海中心大厦为例

上海中心大厦是位于浦东陆家嘴核心区的超高层建筑,其室内外园林的设计与施工难点众多,笔者带领的施工团队对任务准备充分,在设计与施工过程中多有创新,使得项目顺利完成,为上海新地标建筑增添了绿色生命力。本文将详细阐述项目过程中的难点与创新,以期将该实践项目中总结的经验等与相关工作者分享。     

Ultrafast terahertz responses in monolayer graphene

ABSTRACT

We theoretically investigate the ultrafast terahertz (THz) properties of monolayer graphene. The analytical formulations of the photon carrier, electric polarization and optical current are obtained by solving the Bloch-equations in present of the ultrafast THz Gaussian pulse. Graphene shows a large nonlinear and ultrafast optical response at THz frequencies due to the gapless and relativistic Dirac particles with nearly linear energy dispersion. It is found that the photon carrier density, electric polarization and optical current density increase with increasing the frequency of the THz pulse. These theoretical results are in agreement with recent experimental findings. This study confirms further that graphene exhibits important features and is relevant to the applications in the ultrafast THz fields.     

Planning for Health: Complexity of Environmental Health and Planning Responses

China's rapid urbanization has led to increasing environmental health problems, which poses great challenges to urban sustainable development. In order to explore the scientific issue of planning for health, this paper firstly analyzes the challenges of spatial planning caused by environmental complexity in terms of health risk, environmental impact, and residents' behavior. And then it puts forward an analytic framework that includes three basic modules, i.e., theoretical model, regional health risk identification, and planning performance assessment, thereby finally proposing six spatial planning strategies according to the objectives of health protection, health promotion, and health equity, on the basis of the actual situation of health risk exposure, environmental friendliness, and the aging level in different cities of China.