首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   54篇
  免费   3篇
安全科学   3篇
废物处理   2篇
环保管理   11篇
综合类   6篇
基础理论   11篇
污染及防治   12篇
评价与监测   9篇
社会与环境   2篇
灾害及防治   1篇
  2023年   3篇
  2022年   2篇
  2021年   1篇
  2020年   1篇
  2019年   3篇
  2018年   2篇
  2017年   6篇
  2016年   3篇
  2015年   3篇
  2014年   3篇
  2013年   4篇
  2012年   1篇
  2011年   3篇
  2010年   3篇
  2009年   1篇
  2008年   3篇
  2007年   2篇
  2006年   4篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1998年   2篇
  1996年   1篇
排序方式: 共有57条查询结果,搜索用时 15 毫秒
1.
2.
This article reports the results of a study that explored whether outdoor recreational areas are sufficient in Istanbul in terms of their surface area and facility characteristics. All the municipalities in 32 subprovinces of Istanbul were sent a survey in 2007 and asked to prepare a list of their outdoor recreational areas including their names, addresses, size, and facilities. All the data collected from the municipalities were used to create a GIS-based inventory by using GIS and remote sensing. As the study revealed, the outdoor recreational areas in Istanbul are far behind meeting the recreational needs of the residents in terms of area per person and facility characteristics. There are 2,470 areas which were dedicated to outdoor recreational activities in Istanbul. Total surface area of all these outdoor recreational areas is 19,2 sq kilometers; this means 1.52 m2 recreational area per person in the city. This value is very low when compared to that of many cities in Europe and USA. As the study also revealed, the majority of outdoor recreational areas in Istanbul are poor in facility. Majority of the existing outdoor recreational areas are small and do not provide the public with many opportunities to engage in different outdoor activities. A more sustainable and efficient recreational plan is needed in Istanbul to meet the various recreational needs of its residents.  相似文献   
3.
4.
5.
Tuberous sclerosis (TSC) is a frequent autosomal-dominant condition (affecting 1 in 6000 individuals) caused by various mutations in either the hamartin (TSC1) or the tuberin gene (TSC2). This allelic and non-allelic heterogeneity makes genetic counseling and prenatal diagnosis difficult, especially as a significant proportion of TSC cases are due to de novo mutations. For this reason the identification of the disease causing mutation is mandatory for accurate counseling, yet current mutation detection methods such as single-strand conformation polymorphism (SSCP) or denaturing gradient gel electrophoresis (DGGE) are labor intensive with limited detection efficiency. Denaturing high-performance liquid chromatography (DHPLC) is a high-throughput, semi-automated mutation detection system with a reported mutation detection rate close to 100% for PCR fragments of up to 800 bp. We used a recently described DHPLC assay allowing the efficient detection of mutations in TSC1 to analyze the DNA extracted from a chorion villus sample in order to perform a prenatal diagnosis for TSC. The fetus was found not to have inherited the deleterious mutation and the DHPLC diagnosis was confirmed by haplotype analysis. This represents the first DHPLC-based prenatal diagnosis of a genetic disease. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
6.
The aim of this study was to determine the level of 26 polycyclic aromatic hydrocarbons (PAHs) at parking garages and to provide the necessary annual information based on occupational inhalation exposure and non-occupational inhalation exposure, which carry risks for the environment. For this purpose, 22 samples were collected continuously from both gas and particulates phase PAHs from two parking garages at Konya City Center, Turkey. The exposure-based risk of these samples was evaluated using concentrations of the carcinogenic PAH compounds. None of the 26 PAHs measured had values exceeding the recommended exposure limits (RELs) standard values for inhalation rate recommended by the World Health Organization (WHO). Exposure levels of gas and particulate PAHs for the occupational group and the public (children and adults who spend time in shopping centers) were found to be 0.07–28.24 μgm?3 and 0.05–5.753 μgm?3, respectively, representing levels two to four times higher than those at the control site. Maximum daily inhalation of B[a]Py was estimated at 1.33 ngd?1 for exposure of the public and as 274 ngd?1 for the occupational group. It is believed that traffic makes a substantial contribution to the PAH profile, which had relatively high concentrations of naphthalene (Napth) and coronene (Coro). Highly carcinogenic dibenzo(a,l)pyrene (B[al]Pyre) was found in the ambient air at two parking garages. Napth and phenanthrene (Phen) were the main compounds found in nearly all the tested samples. In this study, benzo[e]pyrene (B[e]Py) was used as a reference for PAHs because its concentration is stable and does not change seasonally. Considering the importance of these compounds in relation to human health, the aim of this work was to characterize and quantify the more toxic PAHs in parking garages. Conducting PAH sampling and their chemical analysis is very costly and labor intensive. This study produced data that can be a powerful tool for environmental forensics.  相似文献   
7.
Elmendorf SC  Moore KA 《Ecology》2007,88(10):2640-2650
There is currently no consensus on how physical and biological factors affect competitive intensity. Tests of whether competitive intensity varies along axes of environmental change have commonly been conducted in systems with a single strong environmental gradient, such as productivity, a soil resource, or an environmental stress. Frequently, these same axes are associated with changes in species composition, yet few studies have asked whether shifts in the identity of competitors affect competitive intensity. We ask whether resources (nutrients, water), stressors (heavy metals, Ca:Mg ratio), productivity (aboveground biomass), or species identity (an ordination axis of plant community composition) were the best predictors of the intensity of competition in a heterogeneous grassland landscape that included multiple independent environmental gradients. The reproductive fitness of six annual plant species was measured in the presence and absence of competitors and used to calculate relative interaction intensity (RII). We found that RII was best predicted by community composition. Nutrient availability was also important, and a post hoc test showed that competitive intensity was best explained by the combined effects of community composition and nutrient availability. We argue that community composition may be the most effective metric for predicting competitive intensity in many ecosystems because it includes both the competitive effects of the local community and information about covarying environmental characteristics.  相似文献   
8.
A simple, easy to use and selective spectrofluorimetric method for the determination of trace levels of aluminium has been developed. A new Schiff base, N-o-vanillidine-2-amino-p-cresol (OVAC), has been synthesized and its fluorescence activity with aluminium investigated. Based on this chelation reaction, a spectrofluorimetric method has been developed for the determination of aluminium in samples buffered at pH 4.0 using acetic acid-sodium acetate. The chelation reaction between Al(iii) and N-o-vanillidine-2-amino-p-cresol was very fast, requiring only 20 min at room temperature to complex completely. The excitation and emission wavelengths were 423.0 and 553.0 nm, respectively, at which the OVAC-Al complex gave the maximum fluorescence intensity at pH 4.0 in a 50% ethanol-50% water medium. The interference from fluoride ions was minimized by the addition of Be(2+). Other ions were found not to interfere at the concentrations likely to be found in natural waters. Under these conditions, the calibration plot was linear up to 1000 microg L(-1) (r = 0.999). The limit of detection (3sigma) for the determination of Al(iii) was 0.19 microg L(-1) and the precision for multiple determinations of 3 ng mL(-1) Al(iii) prepared in ultra-pure water was found to be 0.29% (n = 16). The Schiff base ligand could be used to determine ultra-trace aluminium from natural waters. Analysis of environmental certified reference materials showed good agreement with the certified values. The procedure was found to be equally applicable to both fresh water and saline solutions (including sea water) using either normal external calibration or the standard additions method.  相似文献   
9.

Introduction  

A chemometric evaluation has been done to classify metal ions in soils and to determine whether or not the gastric and intestinal phases of a physiologically based extraction test bear any relation to any of the phases of the four-stage Community Bureau of Reference (BCR) extraction protocol.  相似文献   
10.
A decision support system has been developed for urban air quality management in the metropolitan area of Istanbul. The system is based on CALMET/CALPUFF dispersion modeling system, digital maps, and related databases to estimate the emissions and spatial distribution of air pollutants with the help of a GIS software. The system estimates ambient air pollution levels at high temporal and spatial resolutions and enables mapping of emissions and air quality levels. Mapping and scenario results can be compared with air quality limits. Impact assessment of air pollution abatement measures can also be carried out.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号