基于web的面向对象模型库系统

本文通过面向对象建模技术的引入和web的引入实现了模型库的共享。同时,本文构建了基于web的面向对象模型库系统,并给出了该系统总体结构、详细结构及各个模块的功能分析和设计细节。在此基础上,本文进一步讨论了GIS与模型库系统的集成问题。最后,本文以广东省水土保持管理信息系统中的模型库为例,作进一步说明。     

高压喷射灌浆防渗技术在水库大坝基础处理中的应用

高压喷射灌浆防渗技术是国内正在推广的一种新型防渗技术,适用范围较广。阜康市红山水库始建于70年代,当时未对坝基11.5~4.2m厚漂卵砾石层进行防渗处理。本次除险加固对坝基采用了高压喷射灌浆防渗处理,经检测防渗质量满足相关规范要求。高压喷射灌浆技术在漂卵砾石层中的成功应用,对该项技术的推广具有参考价值。     

近断层地震作用下基础隔震层组合限位振动台实验研究

近断层脉冲型地震作用下,基础隔震结构隔震层会产生过大变形,导致隔震支座侧倾失稳,隔震体系破坏。设计制作了3层基础隔震钢框架实验模型和11种U型钢板I型铅棒组合限位器,进行了U型钢板静力加载实验和近断层脉冲型地震作用下基础隔震层软碰撞限位振动台模型实验。实验表明：①静力加载时,U型钢板具有很好的弹性性能;②动力作用下,组合限位器残余变形较小,仍具有良好限位复位能力;③近断层地震作用下,基础隔震层软限位效果良好,同时控制上部结构层间变形在允许范围内。     

超宽带应急定位基站布设研究

针对应急场景下人员位置难以确定的问题,通过合理布设超宽带定位基站,能为人员位置确定提供有力支撑。该文设定了4种定位基站布设方案,通过仿真定位实验统计分析了不同布设方案中精度因子(DOP)值的分布,通过实测定位实验统计分析了测试轨迹的DOP值变化和测试点位的定位误差。结果显示,测试点位的DOP值的变化受到定位基站布设的区域范围、数目和高度等因素影响,当测试点位在基站所围成的几何图形的封闭区域内部、合理增加基站数目以及测试点位与基站的高度角较大的情况下,测试点位的VDOP值和PDOP值较小;同时,定位终端与基站的几何构型影响测距误差,进而影响定位误差。表明,通过合理布设定位基站,优化定位终端与基站的几何构型,减小DOP值,同时顾及测距误差影响,从而提高终端定位精度。     

Analysis and evaluation on seepage stability of Hongxing reservoir dam,Heilongjiang

Hongxing reservoir was constructed on the floodplain of Hulan River in Heilongjiang. The geological problem of the reservoir is the seepage of the dam base and its related seepage stability. The leakage of the reservoir is caused by the water head differences between the upstream and downstream of the dam. Severe seepage could decrease the engineering benefits of the reservoir. Moreover, infiltration function of water will influence the safety of the dam. Through the analysis on the granule constitute and the formation of the dam base, the types of the seepage failure apt to happen were defined and the anti-infiltration and the permissible depression ratio were determined. Using the numerical simulation software GMS, the two-dimension numerical modeling has been carried out to analyze the seepage field of the reservoir. Through the two conditions modeling with concrete impervious wall and no concrete impervious wall, the largest flow rate, single-wide seepage discharge and the max infiltration gradient of the dam base were calculated. According to the permeable depression ratio of the dam base, the seepage stability of Hongxing reservoir dam base was analyzed.     

数字地质图的特点及制图时应注意的几个问题

随着GIS技术引进地质领域,数字地质图全面取代了传统地质图。它克服了模拟地质图的缺欠,可快捷地实现投影变换、随意确定比例尺、任意选择显示范围、选取内容及内容的表达方式等,是今后地质成果的重要表现形式。     

Estimates of current and historical fluxes of N, Ca, and K in the forest ecosystem Möhlin

Data on element fluxes (Ca, K, N) are presented which were obtained in the course of an extended project on element-cycling in a forested ecosystem near Möhlin, northwestern Switzerland. Current fluxes of Ca, K, and N could be compared with historical fluxes (1969–1993) with the help of soil chemistry inventories since 1969, data on the forest management, and atmospheric deposition. Since 1969, soil chemistry has significantly changed due to a distinct disintegration of humus. The decomposition of organic matter influenced strongly the element cycling. Due to this mineralization high amounts of N were released. It is, however, not fully clear in which chemical form N has been transferred out of the system. Two possible hypotheses on the N losses are defined. According to the calculated proton budget and measured element changes in the soil, it is hypothized that a large part of the mineralized organic N presumably was transformed into N₂ or more likely into N₂O. A complete nitrification of organically bound N to NO₃ ^– is also discussed but is, however, considered as less probable. In contrast to K, Ca proved to be a very sensitive element: the exchangeable Ca stock has been decreased sharply. The analysis of the current fluxes of Ca, K, and N reveals that nitrogen is abundantly present in the forest system with the consequence that the ecological balance is shifted in favour of N. Accordingly, the supply of base cations is rather scarce for the plants. Furthermore, the influence of forest management on element fluxes seems to be substantial, especially on the fluxes of base cations, but can be reduced with simple measures (e.g. removal of the bark of coniferous trees).     

平面图绘制程序及其在地质图件数字化中的应用

介绍了“常用地质图件软件”子系统“平面图绘制程序”的设计思路、设计程序和使用技巧,并通过具体的实例,说明了程序中各种参数的设置和在矿井地质图件中的应用.     

金华市山区无公害蔬菜基地环境质量评价

该基地环境质量优良 :水质综合污染指数 0 .37( 级 ) ,大气质量几何均数指数0 .68( 级 ) ;各种重金属元素含量均在浙江省土壤元素变化范围内 ;土壤中六六六、DDT、As的含量和基地内主产蔬菜的抽检指标均符合绿色食品卫生标准 .当地适宜发展无公害蔬菜