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固相萃取-气相色谱法测定水样中马拉硫磷残留   总被引:2,自引:2,他引:0       下载免费PDF全文
采用C-18小柱萃取、毛细管柱分离、气相色谱氢火焰离子化检测器(FID)测定水样中的马拉硫磷,检测限为0.12μg/L。试验了样品流量和洗脱剂对回收率的影响,结果表明样品流量为6mL/min、二氯甲烷作洗脱剂时,回收率较好。测定蒸馏水、地下水和河水样品,相对标准偏差〈2.2%。加标回收率在79.0%-109%之间。  相似文献
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Changzhou is a typical waterside municipality with approximately 2,500 years of history located south of the Yangtze River. It was an agriculturally oriented region but is becoming an industrialized region. Rural green landscaping in this region possesses characteristics of traditional Chinese gardens. This paper presents a methodology for assessing the visual quality of green landscaping in rural residential areas through public perception-based and expert/design approaches. The former approach enables us to rank green landscaping based on a survey of public preference; the latter weighs the contributions of the attributes contained in a photograph to its overall scenic beauty via correlation, regression, and factor analyses. The photographs used in the survey included road greenways, riparian greenways, residential public gardens and green landscaping around houses, with each type of landscape represented by seven photographs. In total, 141 college students and 41 other participants ranked photographs of each landscaping type from highest to lowest preference. The results indicate that the preferences of students are similar to those of the general public. Examples of green landscaping depicted in the “best” four photographs possessed more attractive qualities regarding the variety of vegetation, richness of colors and a selection of human additions compared to those depicted in the “worst” photographs. The perceived visual quality was positively influenced by, in decreasing order of importance, the variety of vegetation, color contrast, the openness of green spaces, the area of vegetation, and positive man-made elements; conversely, it was negatively influenced by the type of topography. Moreover, some suggestions were offered for future rural greening regarding perceived visual beauty.  相似文献
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简述了中国环境保护多项业务中污染源代码现状,其污染源编码都是根据当时的环境管理工作需要,独立确定的一套编码规则,这些不同的标识方式,在污染源的编码格式上不具有稳定性与统一性,不利于污染源基础信息的共享,形成多个信息孤岛。提出了基于组织机构代码的污染源编码规则,确定了编码结构及表示形式,使新污染源编码规则具有较强的实用性、标识的唯一性以及结构的规范性。基于污染源代码,可以有效整合环境信息资源,形成污染源档案,为环境监管提供全面的、详实的数据支撑。根据当前环境管理业务信息系统的实际,提出了今后实施工作的建议。  相似文献
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