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91.
GIS软件的发展方向研究 总被引:1,自引:0,他引:1
GIS软件发展到现在已经到了一个比较成熟的阶段。开源GIS的提出,从本质上为GIS软件的新发展提供了方向。开源GIS以开放、分享的特点将会成为以后GIS软件研发的主流方向。文章概述了开源GIS的基本构架、数据类型和优势特点,同时从研发角度以及商业角度分析了开源GIS的意义。 相似文献
92.
矿山数据资料多,在勘查阶段设计后续钻孔工程时经常要查阅之前的钻孔资料。本文是在整理马来西亚吉兰丹州Ulusokor金矿区钻孔资料过程中用Access设计的一个简单查询界面,充分利用了Access用户友好的操作界面及其查询修改记录的强大功能,使得查询起来不再麻烦,既有利于资料整理,又有利于后续工程的布置。 相似文献
93.
介绍利用Access97编制科技论文登记数据库的具体过程及使用方法。通过该数据库,可以及时将发表的科技论文入库。当论文全部入库后,可以方便地进行查询及统计,从而得出有效的数据,大大提高了工作效率。 相似文献
94.
I. ISTIARTO W.H. GRAF Res. Asst. Lab. de recherches hydrauliques Ecole Polytechnique Federale Lausanne Switzerland. E-mail: adhy.kurniawan@epfl.ch or istiarto@tsipil.ugm.ac.id Prof Lab. de recherches hydrauliques Ecole Polytechnique Federal 《国际泥沙研究》2001,(4)
1 INTRODUCTION'LOcal scour around a pier is a result of the interatiOn amongst the pier, the aPproach flow and theerodible bed. The Presence of a pier results in a stagnation pressure build-up in front of the pier and athree-dimensional tUrbulent flow echaracterized by the downward flow ahead of the pier and the so-called horseshoe vortex along the base of the Pier forms itself The flow modifies the erothe bed inthe vicinity of the pier when local scour takes place (Graf and AJhnakar l… 相似文献
95.
《国际泥沙研究》2020,35(6):621-635
The objective of the proposed method is to utilize a site investigation of a debris flow disaster and verify a real scale analysis to evaluate the impulsive load on an open sabo dam. The Nagiso debris flow disaster which occurred in Nagano in 2014, where damage caused by Typhoon Neogri was studied. The verification result of the site investigation demonstrated the weak components of the open Sabo dam experienced damage owing to the debris flow. A discrete element method is normally applied to a solid body to calculate an interaction function force with respect to the contact point between boulders and the dam. The numerical method initially concatenates elements that model the open Sabo dam. Moreover, the stiffness coefficient of flanges and coupling joints between pipes was expressed to utilize the sectional partition method to determine the structural characteristics. The method was improved to separate from the connecting elements beyond the boundary conditions. The debris flow model uses a water flow distribution model, and the debris flow flowed from 200 m upstream of the open sabo dam. Accordingly, the proposed method was examined to verify the primary cause of damage to the open sabo dam and used to reproduce the circumstances that evaluated the impulsive load occurrence mechanism in the case of a real disaster. In addition, the coupling joints between the hollow steel pipes utilized a ‘reproduction analysis’ for a real sabo dam and a ‘reinforced analysis’ for a reinforced sabo dam were applied to assess the weak point of the dam. 相似文献
96.
In three Larrea shrublands, cacti grow under Larrea canopy at northern and southern exposures and in open spaces were counted. Cacti distribution was related to environmental variables. Seven out of the 15 cacti present were found to be associated with shrubs, whereas the other species were found in the open spaces. The lower temperature and radiation occurring under shrubs at south exposures would explain the absence of cacti in these places. The higher organic matter, nutrients, and moisture in the soils under shrubs appeared to be correlated with higher cacti density. The presence of cacti seedlings only under shrubs could be attributed to the favourable environmental conditions for cacti seed germination and seedling survival that occurred in these places. 相似文献
97.
The determinants of primary health care utilization: a comparison of three rural clinics in Southern Honduras 总被引:2,自引:0,他引:2
Primary health care utilization is poorly understood in many parts of the developing world. This is especially true in rural places, such as Santa Lucia, Intibuca, Honduras, where there are only three primary health care facilities servicing almost 12,000 people, and generally speaking access to care is limited. This study examines the factors that can be used to explain primary health care utilization, and aims to improve the understanding of patient utilization behavior. A better understanding of utilization can be used by health service planners to improve primary health care delivery in this and similar locations. The findings of this research indicate that utilization can be explained, to a large extent, by factors relating to economic status and walking time to clinic. These findings are consistent with findings from prior research. In addition, a home territory variable is used to examine spatial variations of utilization behavior. This variable has not been considered in previous utilization research, and is found to be a very significant determinant of health facility utilization in the study area. 相似文献
98.
The fluid flow system can be described by an equivalent electromagnetic system. In this paper a successful application of the Biot–Savart law in hydraulics is presented. Similarity between the magnetic field of a current wire and the isovel contours in a channel cross-section is used to derive the isovel patterns in an open or closed channel. Having obtained the normalized isovel contours, one can easily obtain the discharge using a single point of velocity measurement at the conduit cross-section. The estimated discharge, based on measured points and the predicted isovels on the upper half of the flow depth away from the boundaries was within ±5% of the measured and much better in comparison to the prediction of one- and two-point methods. Furthermore, the model was applied to real life channels. The prediction of the water surface velocity for the River Unon in Japan and depth-averaged velocity for the Severn River in UK show a good agreement with the measured data and analytical results. 相似文献
99.
Secondary motions are commonly present in open channel flows. This study aims to investigate, both experimentally and analytically, time-mean characteristics of cellular secondary flows generated by longitudinal bedforms. Experiments were conducted in a tilting, rectangular flume with six different longitudinal bedforms, including alternate bed strips with different roughness heights and bed ridges of wavy and rectangular shapes. Various flows were sampled using a two-dimensional laser Doppler anemometer (LDA) and a one-dimensional ultrasonic Doppler velocimeter (UDV). Experimental results demonstrate secondary flows appearing basically in cellular fashion over the modeled longitudinal bedforms. It is also shown that the cellular structures can be described analytically with kinematic considerations. The discrepancies between theoretical and measurement results are discussed. An empirical relationship between maximum vertical velocity and bed configuration is finally proposed based on the experimental data. 相似文献
100.
厦门经济特区城市发展与布局研究 总被引:1,自引:0,他引:1
陈怡煌 《云南地理环境研究》1991,3(1):74-82
厦门是座海岸一港岛复合型城市。为中国“经济特区—经济技术开发区—沿海经济开放区”有机结合带,它又是全国计划单列城市和福建改革开放综合试验区。多层次的对外开放和多元结构的改革试验,为区域开发、城市空间布局和多功能构建注入了新活力。台湾海峡两岸关系的改善使之成为投资热点,提高了它在完成祖国统一大业中的特殊战略地位。本文以地理学的观点,分析了世界经济特区的基本模式和中国经济特区城市的基本职能,探讨了厦门设置特区的因由、吸引腹地、城市性质、产业开发、城市空间格局,并对特区城市的高新技术开发作了初步论证。 相似文献