排序方式： 共有39条查询结果，搜索用时 31 毫秒
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Srinivasa Reddy M Basha S Sravan Kumar VG Joshi HV Ghosh PK 《Marine pollution bulletin》2003,46(12):1609-1614
Alang–Sosiya located on the Western Coast of Gulf of Cambay, is the largest ship recycling yard in the world. Every year on average 365 ships having a mean weight (2.10 × 106 ± 7.82 × 105 LDT) are scrapped. This industry generates a huge quantity of solid waste in the form of broken wood, rubber, insulation materials, paper, metals, glass and ceramics, plastics, leather, textiles, food waste, chemicals, paints, thermocol, sponge, ash, oil mixed sponges, miscellaneous combustible and non-combustible. The quantity and composition of solid waste was collected for a period of three months and the average values are presented in this work. Sosiya had the most waste 15.63 kg/m2 compared to Alang 10.19 kg/m2. The combustible solid waste quantity was around 83.0% of the total solid waste available at the yard, which represents an average weight of 9.807 kg/m2; whereas, non-combustible waste is 1.933 kg/m2. There is not much difference between the average of total solid waste calculated from the sampling data (96.71 MT/day) and the data provided by the port authorities (96.8 MT/day). 相似文献
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生态敏感性分析是城市规划编制研究的重要依据,运用GIS空间分析技术可以有效地实现生态敏感性定量分析。文中以环滆湖地区为研究区,选择海拔、水域、农田、水源保护区、生态保护区和建成区六项有区域代表性的生态因子,借助GIS空间缓冲区分析、叠加分析等功能,采用因子叠加取最值法得到规划研究区的总体生态敏感性区划,对研究区生态敏感性进行定量化分析与评价,为环滆湖地区的生态环境保护和空间管制规划策略制定与用地空间合理布局提供科学依据、方法支撑和决策支持。 相似文献
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精密单点定位技术（precise point positioning,PPP）虽可以提供全球厘米级定位,但是需要数十分钟实现收敛,而PPP-实时动态定位（real-time kinematic, RTK）则依赖区域参考站以提供大气延迟改正信息,限制了系统服务范围。实现了一种多频多模观测值PPP方法,仅需要卫星轨道、钟差和信号偏差即可实现全球范围内的瞬时厘米级定位,解决了PPP收敛慢、PPP-RTK服务范围有限和成本高的难题。结合现有星基增强改正数编码和播发方式,构建了一个兼容北斗PPP-B2b服务的广域瞬时厘米级服务系统,并评估了其轨道、钟差和信号偏差等增强信息精度。中国区域静态和车载动态数据验证结果表明,该系统可以95%的置信率在1 min内实现厘米级精密定位,可满足自动驾驶等领域对快速、高精度和高可信定位的需求。 相似文献
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Coastal changes at the Sulina mouth of the Danube River as a result of human activities 总被引：2，自引：0，他引：2
Sulina, the middle distributary of the Danube Delta, has been significantly changed by human activities over the past 150 yr. These include engineering works in the second half of the 19th century, when the channel was transformed for navigation and the construction of jetties which nowadays extend 8 km seawards. These interventions have strongly affected the natural processes of the Black Sea coast near the Sulina mouth. To the south of the Sulina mouth, the natural mild erosion has been reversed in the area close to the jetties where accretion is occurring, while southwards the greatest erosion rate along the entire Romanian coast, of more than 20 m/yr, has been recorded. Sediment accumulation in the northern part of the mouth is also huge and has brought to the creation and swift elongation of a sediment spit in several decades. Thus, the bay located here suffers from a rapid transformation into a lagoon. 相似文献
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在三频GNSS应用中,受精密产品频率基准不一致的影响,会引入系统性偏差,即频间时钟偏差（IFCB）。本文首先通过对IFGF组合观测值进行历元差分,利用全球分布的80个MGEX观测站及中国区域内100个连续运行参考站,在2021年年积日（DOY）153—160 d的实测数据,进行了IFCB的估计并分析了其时变特性;然后将IFCB的估计结果运用到非差非组合PPP中。结果表明：GPS BLOCK Ⅱ-F的IFCB较大,幅值可达14 cm,GPS BLOCK Ⅲ与BDS的IFCB则较小,一般不超过5 cm。在定位验证中,经过IFCB改正后,GPS/BDS-2/BDS-3-IGSO在第3频点L5、B2I、B2a的相位残差分别减小了59.54%、26.31%、10.98%。其中,动态定位的GPS、BDS-2/BDS-3-IGSO、GPS/BDS-2/BDS-3-IGSO 3种方案的点位精度分别提升了56.55%、29.16%、20.72%,改善效果显著。 相似文献
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对比了传统测量方法与三维激光扫描技术,得出在城市地下空间测量中,三维激光扫描技术具有速度快、数据全面、精度可靠等特点。并对其外业数据采集及内业处理、信息提取等流程进行了介绍。 相似文献
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研制了测定岩石、矿物及矿石中０．０１－１００μｇ／ｇ的砷、锑、硒和碲的原子吸收方法，该方法建立在通过从含硫－溴化物溶液中用乙烯－１和甲苯的混和物萃取这些经预富集的元素的基础上。硒和碲作为附加到烯烃双链上的有机金属化合物－亲电子产物被不可逆地萃取。就砷和锑来说，可产生与甲苯络合的分了了溴化物的可逆萃取。 相似文献
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大地高转换正常高是工程测量中的重要工作之一。本文针对影响多项式高程转换精度的地形、拟合模型的选择以及拟合点布局三种因素,选取西北某地区平原、丘陵和山区地形进行区域高程转换精度研究。同时,分析了三种地形条件下拟合点布局对多项式拟合模型的影响。通过实验结果,得到了该拟合方法在高程转换中的定量结论,可为实际相关工作提供参考。 相似文献
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