全回转套管钻机和全套管施工工艺的研究

简述了全回转套管钻机的国内外研究现状和应用领域。主要介绍了QHZ-2000型全回转套管钻机的设计结构、技术参数、关键技术。分析了全回转套管柱、冲抓斗、清障钻具的结构原理和应用特点。总结了全回转套管灌注桩、全套管清障和全套管拔桩的施工流程、机理和适用范围。研究填补了国内自主研发全回转套管钻机的空白,是一种适合在城市施工的绿色环保、广谱安全的无循环桩基施工新设备和新技术。     

中国东北沿边少数民族地区发展的障碍因素分析——以延边朝鲜族自治州为例

改革开放以来,尤其是实施西部大开发、东北等老工业基地振兴等战略实施以来,我国东北沿边少数民族地区的社会经济发展并不尽如人意。以延边朝鲜族自治州为例,其经济发展一直处于低位运行,与该地区的自然禀赋和所享受的西部大开发、东北等老工业基地振兴等优惠政策极不协调。从边缘的区位条件、特殊的地缘环境影响、地理环境对资本投资的障碍、产业结构的刚性制约、有限的经济腹地、劳动力日益减少与生态功能的限制等七个方面探讨其区域社会经济发展的障碍因素,并尝试透过延边朝鲜族自治州这一个案,探讨我国东北沿边少数民族地区社会经济发展的突破口。     

外向型经济地区小城镇土地利用特征及体制性障碍--以东莞市寮步镇为例

以东莞市寮步镇土地利用为例进行研究,认为外向型地区小城镇具有城镇建设用地扩张迅猛、工业用地需求大增的需求特征和土地供给主体多元化、供给方式多样化、土地收益高等供给特征;而且在这些地区存在土地批租出让超前、土地闲置、土地利用粗放等土地市场供需体制问题和违法用地、土地规划管理不力等管理体制问题.文中从土地的供需体制和管理体制方面对产生以上问题的原因进行剖析,并对土地利用体制改革问题提出相应的对策和建议.     

基于Google Earth的机场OAS面障碍物评价

本文提出了一种基于Google Earth二次开发实现机场精密进近OAS面建模和障碍物评价的新方法.使用KML语言描述机场的精密进近OAS面和障碍物,通过Google Earth提供的可扩展接口将控制Google Earth地图显示窗口嵌入到系统主窗口,结合评价算法对精密进近OAS面内障碍物自动评价.     

综合处理办法在城市复杂地段桥桩施工中的应用

在北京市德内大街桥桩施工过程中,不仅遇到交通拥堵．场地狭小．地上地下障碍物等多种不利条件．而且在拟施工的桩位处遇到大量原有河道的加固材料,物品种类之多、数量之大、埋深之厚,实属罕见,施工条件极差、施工难度极高,施工单位最终通过采取多种办法、措施解决了这些难题,圆满的完成了桥桩施工任务。本人认为在旧城复杂地段施工时,综合处理措施具有很大发展空间,值得深入研究发展,在旧城改造的类似工程中具有一定借鉴作用。     

青岛奥帆竞赛海域扫测工程的实施

为掌握青岛奥帆基地重点海域海底水深数据、地形地貌及障碍物分布特征,采用多波束测深系统对该区海域进行了全覆盖、高效率的海底地形扫测,经过高精度的数据处理,编绘得到海底地形地貌图,并发现了可疑沉船、暗堤等海底障碍物的分布,保障了奥帆赛事的顺利进行.     

山东机场发展中的主要问题与对策

目前80％的中国民航机场处于亏损,山东省机场就是一个缩影。文章分析了山东省机场的发展现状及存在的主要问题：分布密度不足、民用数量太少、等级总体偏高、网络结构欠佳等,认为机场发展水平过度超前于经济发展水平是造成目前机场亏损的根本性原因。在此基础上,提出4条有针对性的对策。     

Modelling potential movement in constrained travel environments using rough space–time prisms

The widespread adoption of location-aware technologies (LATs) has afforded analysts new opportunities for efficiently collecting trajectory data of moving individuals. These technologies enable measuring trajectories as a finite sample set of time-stamped locations. The uncertainty related to both finite sampling and measurement errors makes it often difficult to reconstruct and represent a trajectory followed by an individual in space–time. Time geography offers an interesting framework to deal with the potential path of an individual in between two sample locations. Although this potential path may be easily delineated for travels along networks, this will be less straightforward for more nonnetwork-constrained environments. Current models, however, have mostly concentrated on network environments on the one hand and do not account for the spatiotemporal uncertainties of input data on the other hand. This article simultaneously addresses both issues by developing a novel methodology to capture potential movement between uncertain space–time points in obstacle-constrained travel environments.     

Large-Eddy Simulation of Turbulent Organized Structures within and above Explicitly Resolved Cube Arrays

Large-eddy simulations have been performed for fully developed turbulent flow within and above explicitly resolved simple cube arrays. The results from our model, hereafter LES-CITY, are shown to agree with laboratory experiments. We investigated the systematic influence of cube density on turbulent flow characteristics by performing numerical experiments for cube areal densities from 0 to 44%. The following results were obtained: (1) The dispersive momentum flux was quite large within the canopy layer due to a mean stream re-circulation, whereas it was smaller above the canopy. The spatial variation of temporally averaged momentum in the roughness sub-layer was 20% or less of the total kinematic surface drag. (2) The temporally and spatially-averaged flow structure confirmed the existence of conventionally described canyon flow regimes; isolated, interfacial, and wake. However, the intermittency of the canyon flow for all cube densities was quite large and the stream patterns were never persistent. (3) Turbulent organized structures (TOS) similar to those observed in turbulent surface-layer flows were simulated, which are characterized by longitudinally-elongated low speed streaks and the corresponding shorter streamwise vortices. The streaks in sparse and dense canopy flows were likely to be aligned to the street line and to the roof lines, respectively. Such heterogeneity of TOS partially accounts for the large spatial variation of momentum flux. (4) In contrast to the mixing layer analogy of vegetation flows, the TOS and the resulting turbulent statistics of urban flow above the canopy resembled those in surface layers. The recirculation within the canopy significantly influenced the turbulent statistical properties.     

我国新能源发展障碍与应对:全球现状评述

以化石能源为主的能源消费模式已经难以满足可持续发展的要求, 改善能源消费结构、减少对化石能源的依赖势在必行。在此背景下, 发展环境友好、地域分布相对均衡且潜力无限的新能源成为各国共识。新能源包括太阳能、风能、生物质能、地热能、海洋能、氢能、天然气水合物、核能、核聚变能等共9种类型。由于种类繁多、资源禀赋和物化特征差异悬殊, 开发利用新能源需要面对比化石能源复杂得多的规划、管理和技术问题。如果措施不当, 不但会造成经济损失, 而且可能会威胁到人类安全。在全面深入了解全球新能源发展现状的基础上, 认真总结各国经验教训, 制定合理的发展战略, 是开发利用新能源的先行性工作, 具有重要意义。本文对国内外新能源资源情况、技术水平、总体发展现状进行分析, 并对我国新能源发展过程中的制约因素进行深入剖析, 结合我国国情提出新能源发展的对策建议。