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91.
92.
收折式可行走架空支承平台施工技术可以降低成本,缩短施工周期,加快施工进度,并不影响被跨越的公路或铁路的正常通行。 相似文献
93.
社会信息化是当代社会的一种大趋势,它正推动着水运公共行政现代化的进程。信息技术的发展对诸如行政人员、行政决策、行政组织、行政方法、行政公文、政府管理模式等公共行政要素和过程产生着深远的影响。 相似文献
94.
徐广舒 《南通航运职业技术学院学报》2009,8(4):22-25
文章以江苏省南通市监理行业知识竞赛为案例,对当前建设工程监理人员的素质现状进行了分析研究,并针对建设工程监理专业人才的素质提高和人才培养提出了见解。 相似文献
95.
Linwood Pendleton 《Coastal management》2013,41(3):239-251
Despite posted warnings and educational campaigns warning about the health risks associated with storm water pollution, swimmers continue to swim in coastal areas polluted by storm water runoff. This study uses a simple spatial model of beach visitation to show how beach amenities and storm drains influence the way in which beach goers choose to locate themselves at beaches in Santa Monica Bay, California. The estimated models indicate that passive means of preventing exposure to marine pollution (e.g., posted signs) could be made significantly more effective if combined with the active management of other beach amenities. Similar methods also could be used to reduce risks to swimmers from other hazards including riptides and boat traffic. 相似文献
96.
Khanh Toan Dam Katsutoshi Tanimoto Eldina Fatimah 《Journal of Marine Science and Technology》2008,13(3):223-230
This paper presents a discussion of the characteristics of ship waves in a narrow channel restricted by vertical walls, based
on observed data and the results computed by a 2-D model. In the numerical model, the propagation of waves generated by a
moving ship is simulated by solving 2-D depth-integrated Boussinesq equations. To get the boundary conditions at the location
of the ship, the slender-ship approximation is employed. A field observation was carried out at a straight length of navigation
channel. The ships targeted in the observations are two kinds of waterbuses with lengths of 28 and 24 m. The relative depth
Froude number for the river current, an appropriate parameter for assessing the influence of the current on ship wave characteristics
in a navigation channel, ranged from 0.47 to 0.76. The observed maximum wave height varied between 0.13 and 1.26 m. The maximum
wave height of the wave train is sharply increased when the relative depth Froude number exceeds 0.6. The results computed
by the present model agree fairly well with the observed data. 相似文献
97.
98.
用户数快速的增长,互联网占用带宽迅速上升,已不能满足业务需求。分析研究铁通分公司省干互联网的改造方案,就重新调整省内互联网出口路由,规范省网出口设置和路由策略,优化互联网业务流量和流向等提出建议。 相似文献
99.
Modelling nutrient fluxes from sub-arctic basins: Comparison of pristine vs. dammed rivers 总被引:1,自引:0,他引:1
Agata Sferratore Gilles Billen Josette Garnier Erik Smedberg Christoph Humborg Lars Rahm 《Journal of Marine Systems》2008,73(3-4):236
The deterministic Riverstrahler model of river functioning is applied for the first time to sub-arctic catchments. Seasonal nutrient (N, P, Si) deliveries to the coastal zone are simulated, and nutrient annual fluxes are established for the nearly pristine river Kalix (hereafter called Kalixälven) and the heavily dammed river Lule, (hereafter called Luleälven) both located in Northern Sweden and draining into the Bothnian Bay, Baltic Sea.For Kalixälven simulations are performed with a runoff calculated from precipitation, evapo-transpiration and temperature data for the period 1990–1999, using a hydrological model calibrated on observed monthly discharges at the river outlet. The same hydrological parameters are used to calculate specific runoff for the Luleälven basin in absence of dam regulation. Reservoir filling and emptying are simulated using a simplified representation of their management rules. Diffuse sources of nutrient are evaluated according to land cover of the catchment. The simulated seasonal trends are within the range of the observed data, in particular for discharge, dissolved silica, total phosphorus, inorganic nitrogen and total organic carbon. Specific runoff is 50% higher in the Luleälven than in the Kalixälven watershed due to higher altitudes and precipitations. Average silica, nitrate and phosphorus concentrations are much lower in Luleälven than in Kalixälven. Comparison of model results for the Luleälven with and without dams shows a reduction of respectively 25% and 30% in silica and phosphorus fluxes delivered at the outlet, while nitrogen delivery is increased by 10% in the dammed vs. undammed river system. The model allows assessing the respective role of reservoir trapping of nutrient in the reservoir through algal uptake and sedimentation, and of changes in the vegetation induced by flooding the valley formerly covered by forests and wetlands. 相似文献