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21.
Since the 1960s tributyl (TBT)-based antifouling paints are widely applied to protect ship’s hulls from biofouling. Due to its high toxicity to aquatic ecosystem most of the countries (28 nations in 2008) signed the AFS convention to control the use of harmful antifouling systems on ships. Nevertheless there is currently no simple method to control the presence of organotin in paint. In this study, we propose a bioassay based on the use of a recombinant bioluminescent bacteria to detect directly in paint the presence of TBT. We also propose a simple device as an inspection system to control the absence of organotin in the ship’s hull paint. The presence of organotin could be revealed in less than three hours. 相似文献
22.
三维模型数据的质量检查是构建数字城市必要环节。为了提高数字城市建设的精度,本文提出了一种数字城市三维模型数据检查方法,本文主要通过平面精度检查、高程精度检查、纹理正确性检查以及合理性检查这四方面,保证了数据生产的精度。并通过数字通州项目验证了三维模型数据检查的全面性。 相似文献
23.
测绘仪器检核管理系统的设计与实现 总被引：1，自引：0，他引：1
本文立足实践，从设计思想、系统框图、主要功能、技术特点、系统评价五个方面，尤其是主要功能(管理模块、校准模块、检定模块、查询模块、打印模块、帮助模块)方面介绍了计算机在测绘仪器校准、检定和管理中的应用。 相似文献
24.
Quantification of groundwater recharge in the city of Nottingham, UK 总被引：13，自引：3，他引：10
Groundwater is an important and valuable resource for water supply to cities. In order to make full and wise use of the asset
value, a clear understanding of the quantities and sources of urban groundwater recharge is needed. The water supply and disposal
network is often an important source of recharge to urban groundwater through leakage from water mains and sewers. An approach
to establishing the spatial and temporal amounts of the three urban recharge sources (precipitation, mains and sewers) is
developed and illustrated using the Nottingham (UK) urban aquifer. A calibrated groundwater flow model is supplemented by
calibrated solute balances for three conservative species (Cl, SO4 and total N), thus providing four lines of evidence to use in the recharge estimation. Nottingham is located on a Triassic
sandstone aquifer with average precipitation of 700 mm/year. Using the models, current urban recharge is estimated to be 211
mm/year, of which 138 mm/year (±40%) is from mains leakage and 10 mm/year (±100%) is from sewer leakage. The wide confidence
intervals result from the scarcity of historical field data and the long turnover time in this high volume aquifer, and should
be significantly lower for many other aquifer systems.
Received: 1 December 1997 · Accepted: 14 September 1998 相似文献
25.
江苏省地质环境监测数据库管理系统———GEMS(V1.0 0 )是用VisualC 6 .0开发的 32位Windows应用程序 ,采用ODBC及SQL进行编程设计 ,实现了对数据库的直接访问和基本操作。系统数据源选取广泛 ,数据结构设计合理 ,各种信息资源提取的自动化、可视化程度较高 ,具有较强的绘图功能。系统充分利用了Surfer、AutoCAD、ModFlow等多种软件 ,扩展了系统的制图及分析计算能力 ,同时提供了DXF、CLP和WMF 3种图形文件转换格式 ,使其具有更广阔的应用前景。 相似文献
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27.
随着越来越重视环境问题,城市污水管道的建设不断增加,大量的污水管道慢慢老化,它们就需要修护和更新。本论文介绍了对污水管道不产生影响的管道检测和评价技术,污水管道防御性维护是非常必要的。 相似文献
28.
1976年唐山大地震引发了范围广、灾害重的液化震害。铁道部科学研究院等单位于1977、1978年对液化场地进行了单桥静力触探测试。但单桥静力触探在数据指标方面存在缺陷,与国际标准不接轨。中国地震局工程力学研究所与东南大学等单位于2007年对上述唐山地区部分测点再次进行了孔压静力触探（CPTU）测试。本文通过对比2次静力触探数据,利用Robertson土质分类图,进行新孔压静力触探数据土类分层检验,将土类检验结果与单桥静力触探测试时钻孔柱状图进行对比,发现大部分测点土层土类均能较好对应,现场测试力学指标沿深度变化趋势较相符,仅剔除了错误点T2、T3。对所有测点选定液化层,分别建立基于单桥静力触探测试比贯入阻力ps和基于孔压静力触探测试锥尖阻力qc的液化数据库。利用基于静力触探测试（CPT）的我国规范液化判别方法检验了2个数据库,发现对单桥静力触探测试的数据库液化判别效果好,而对孔压静力触探测试的数据库液化判别效果较差,说明经过30年的时间,土层液化可能已发生较大改变。因此,基于孔压静力触探测试的液化数据库可靠性较低,基于该数据库对液化判别方法进行改进意义较小。 相似文献
29.
Nitrous oxide emissions from urban wastewater were measured in a combined sewer in Bayreuth, Germany. The closed-chamber method was used to evaluate N2O emissions. Nitrous oxide was analysed by gas chromatography with electron capture detector. Longitudinal and daily variations of N2O fluxes were determined. N2O emissions ranged from 0.11…3.8 mg m?2 h?1 depending on the level of wastewater in the sewer. Data indicate that N2O is mainly formed in the biofilm by nitrification and/or denitrification. In laboratory experiments, samples with wastewater and wastewater/biofilm mixture were incubated with and without NaCl. After two hours of incubation, N2O release was in a range of 42…429 ng N2O per millilitre wastewater or wastewater/biofilm. Incubated samples without NaCl addition showed no significant difference between wastewater and wastewater/biofilm mixture. If salt (NaCl) was added before incubation, samples with wastewater/biofilm mixture emitted 4.8 times more N2O than wastewater samples. It is assumed that high concentrations of NaCl inhibit further microbial reduction of N2O to N2. Based on the field data, a first estimate for N2O emission from sewers is 3.5 g N2O per year and person. 相似文献
30.
A simple model which describes the soil–pipe interaction and accounts for the longitudinal soil variation has been developed. It is used for the analysis of the static response of a section of a buried sewer. A probabilistic analysis (Monte-Carlo method) enabling to quantify the influence of spatial variability of the geomechanical characteristics of the soil makes possible to study the parameters which can influence and drive the longitudinal response of a section of sewer. The system response is complex, soil–structure interaction depending on three different stiffnesses: soil stiffness, pipe components stiffness and joints stiffness. Various analyses have been performed to identify the parameters whose influence is the larger. A specific attention has been devoted to the fluctuation scale of the soil properties and to the stiffness of joints. 相似文献