全文获取类型
收费全文 | 293篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 22篇 |
环保管理 | 32篇 |
综合类 | 21篇 |
基础理论 | 40篇 |
污染及防治 | 85篇 |
评价与监测 | 65篇 |
社会与环境 | 14篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 7篇 |
2022年 | 19篇 |
2021年 | 14篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 6篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 6篇 |
2011年 | 13篇 |
2010年 | 17篇 |
2009年 | 17篇 |
2008年 | 23篇 |
2007年 | 17篇 |
2006年 | 10篇 |
2005年 | 11篇 |
2004年 | 14篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1989年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有296条查询结果,搜索用时 15 毫秒
91.
Sandbars are critical to the cross-shore movement of sediment. Prediction of cross-shore sandbar volumes requires knowledge about the functional relationship of sediment transport rate conditions with waves, currents, base slope, sediment property and water depth. In this study, experiments on cross- shore sediment transport were carried out in a laboratory wave channel for initial base slopes of 1/8, 1/10 and 1/15. Using regular waves with different deep-water wave steepness generated by a pedal-type wave generator, bar volumes caused by cross-shore sediment transport are investigated for beach materials with the medium diameter of d50?=?0.25, 0.32, 0.45, 0.62 and 0.80 mm. A non-dimensional equation for sandbar volume was obtained by using linear and non-linear regression methods through the experimental data and was compared with previously developed equations in the literature. The results have shown that the experimental data fitted well to the proposed equation with respect to the previously developed equations. 相似文献
92.
Recognition and understanding of landscape dynamics as a historical legacy of disturbances are necessary for sustainable management
of forest ecosystems. This study analyzed spatial and temporal changes in land use and land cover patterns in a typical mountain
watershed in the Gumushane district along the Northeastern part of Turkey. The area is investigated by comparing LANDSAT images
from 1987 to 2000 and evaluated the temporal changes of spatial structure of forest conditions through spatial analysis of
forest cover type maps from 1971 and 1987 using GIS and FRAGSTATS™.
The results show a general decreasing trend in area of natural land cover types including broadleaf and conifer forests as
well as coppice between 1971 and 1987 (0.54%, respectively). In contrast, between 1987 and 2000 this natural land cover types
show increasing trend (1.6%). In parallel with forest dynamics, the area of managed land including lowland and upland agricultural
areas, rangelands and grasslands increased during the first period and decreased during second period. In terms of spatial
configuration, Gümüşhane forests aren’t generally fragmented by intensive forest utilization in the latter periods. This is
partially due to out-migration of rural population in Gümüşhane. Nevertheless, land use pattern significantly changed over
time depending on a few factors such as unregulated management actions, social pressure and demographic movements. The study
revealed that demographic movements have a major effect on landscape dynamics. 相似文献
93.
This study aimed at quantifying noise pollution from urban traffic in the city of Kahramanmara?, Turkey. A total of 114 measurements for the equivalent noise level (L Aeq) were made at 38 urban locations classified as “residential areas”, “residential and commercial areas” and “industrial areas” according to the national regulations, during morning, mid-day and evening hours. Our findings tabulated and mapped revealed that mean noise level in “residential and commercial areas” was highest relative to the other land-use types. Minimum and maximum values of noise pollution were recorded during the mid-day and evening hours, regardless of the land-use types. Noise limit values were exceeded at two locations only out of 38 based on the national regulation criteria and at over half of the locations based on the international criteria. 相似文献
94.
Heavy metals in water and in tissues of himri (Carasobarbus luteus) from Orontes (Asi) River, Turkey
Concentrations of heavy metals (Ag, Cd, Cr, Cu, Fe, Ni, Pb ve Zn) were measured in running water and in tissues (muscle, liver, gill, skin and gonads) of one commercially valuable fish species (Carasobarbus luteus) from the Orontes (Asi) River (Güzelburç region) in Hatay (Southeastern Turkey). Results for levels in water compared with national and international water quality guidelines were found at the highest concentrations in international criteria’s WHO, EC and EPA, but Cd, Cu, Ni and Pb were found to exceed permissible level of drinking water in national criteria TSE-266 whereas Fe, Zn and Cr concentrations were within the permissible levels for drinking. The present study showed a significant seasonal variation (p?0.05) in the concentration of the studied metals in the selected tissues, except gonads (p?>?0.05), which showed seasonal variation of only Zn (p?0.05). Maximum concentrations of Ag, Cd, Cr and Pb were detected in gonads followed by liver, gill, skin and muscle while maximum concentrations of Cu, Fe, Ni and Zn were detected in liver followed by other tissues. Concentrations of heavy metals in the muscle of C. luteus were below the permissible limit for human consumption, level of Cu being very close to the permissible limit. Consequently, continuous monitoring of heavy metal concentration in edible freshwater fish will be needed in Orontes River. 相似文献
95.
Evci ED Bilgin MD Akgör S Zencirci SG Ergiń F Beşer E 《Environmental monitoring and assessment》2007,134(1-3):471-477
Objectives The purpose of this study was to determine electromagnetic fields, electric fields, humidity, temperature, and illumination
levels in hairdresser salons located in the downtown area of Aydin, Turkey. Also some health problems which could be related
with the occupational factors are evaluated.
Materials and methods The study was carried out in 30 hairdresser salons, all of which had been registered within the past 5 years. Electric and
electromagnetic fields, illumination, temperature and humidity measurements were determined for hairdryers, hood hairdryers
and depilatory heaters in the participating salons. A brief questionnaire about characteristics and the health status of hairdressers
and workplace conditions was prepared and administered to the hairdressers at the salons.
Results The mean electric fields of hairdryers, hood hairdryers and depilatory heaters were determined as 518 ± 74, 1,123 ± 199, and
648 ± 146 in V/m, respectively, at 5 cm from the surface of each device. These appliances generate mean electromagnetic fields
in excess of 0.25 μT at 5 cm: hand-held hairdryers, 5.0 ± 0.7 μT; hood hairdryers, 1.6 ± 0.3 μT; and depilatory heaters 1.9 ± 0.6 μT.
Total average of cumulative electric and electromagnetic fields, measured at a distance of 90 cm from the surface of these
three devices was calculated to be 98.8 V/m and 0.5 μT, in the participating salons.
Conclusions This preliminary study suggests that physical environmental factors in the salons may be contributing to the health problems
of the hairdressers, and the electrical equipments in the workplaces may have cumulative electric and electromagnetic effects. 相似文献
96.
This study aims to obtain a reliable inventory of the emission rates of the principal air pollutants including PM, SO2, NOx) and CO in Kocaeli, Turkey. In the first stage, the pollutant sources classified as point, area and line sources are determined in the area. Then the annual emission rates of the pollutants released from these sources are estimated by the emission factors given by USEPA and CORINAIR. Results show that the annual emission rates for PM, SO2, NOx) and CO are 2195 tons, 5342 tons, 14632 tons and 23095 tons, respectively. On the other hand, the pollutant group with the highest contribution to total emission rate is determined as the point sources for NOx, which is responsible for 73% of total NOx emission, while it is the area sources for PM, SO2 and CO with the contribution percentages of 75, 76 and 69, respectively. 相似文献
97.
Gökben Başaran Kankılıç İlhami Tüzün Yusuf Kağan Kadıoğlu 《Environmental monitoring and assessment》2013,185(8):6739-6750
In this study, the concentrations of 13 elements (Al, Fe, Mn, Cr, Ni, Zn, Co, As, Pb, Cu, Mo, Hg, and Cd) were determined in the sediments of three different sites in the Kapulukaya Dam Lake between May 2007 and November 2008. They ranged from 1.47 to 4.64 for Al, 0.92 to 3.48 for Fe (in percent), 326.60 to 1053.00 for Mn, 98.00 to 1,116.00 for Cr, 24.70 to 127.10 for Ni, 14.80 to 124.20 for Zn, 11.0 to 43.20 for Co, 5.00 to 29.30 for Cu, 9.10 to 69.70 for As, 8.60 to 34.00 for Pb, 2.50 to 5.20 for Mo, 1.00 to 1.60 for Hg, and 0.50 to1.80 for Cd in microgram per gram dry weight sediment. The contamination degree of the sediment was assessed on the basis of enrichment factor and corresponding sediment quality guideline. The calculated enrichment factors (EF, measured metal vs. background concentrations) indicated that the effect of man-made activities on the occurrence of concentrations could be accounted for the majority of heavy metals namely Mn, As, Ni, Cu, Zn, Cr, Co, Mo, and Cd, whereas such affect was not detected for Hg and Pb. The maximum values of the EF were represented by As, minimum values by Hg at all sites. Mean EF values were 36.60 and 0.70 for As and Hg, respectively. This study has clearly assessed a certain level of heavy metal pollution in the region, based particularly on the findings from sediment. 相似文献
98.
99.
Denise M. Thompson Day B. Ligon Jason C. Patton Monica Papeş 《Conservation biology》2017,31(2):427-436
Survival and reproduction are the two primary life‐history traits essential for species’ persistence; however, the environmental conditions that support each of these traits may not be the same. Despite this, reproductive requirements are seldom considered when estimating species’ potential distributions. We sought to examine potentially limiting environmental factors influencing the distribution of an oviparous reptile of conservation concern with respect to the species’ survival and reproduction and to assess the implications of the species’ predicted climatic constraints on current conservation practices. We used ecological niche modeling to predict the probability of environmental suitability for the alligator snapping turtle (Macrochelys temminckii). We built an annual climate model to examine survival and a nesting climate model to examine reproduction. We combined incubation temperature requirements, products of modeled soil temperature data, and our estimated distributions to determine whether embryonic development constrained the northern distribution of the species. Low annual precipitation constrained the western distribution of alligator snapping turtles, whereas the northern distribution was constrained by thermal requirements during embryonic development. Only a portion of the geographic range predicted to have a high probability of suitability for alligator snapping turtle survival was estimated to be capable of supporting successful embryonic development. Historic occurrence records suggest adult alligator snapping turtles can survive in regions with colder climes than those associated with consistent and successful production of offspring. Estimated egg‐incubation requirements indicated that current reintroductions at the northern edge of the species’ range are within reproductively viable environmental conditions. Our results highlight the importance of considering survival and reproduction when estimating species’ ecological niches, implicating conservation plans, and benefits of incorporating physiological data when evaluating species’ distributions. 相似文献
100.
Yusuf Yavuz Reza Shahbazi A. Savaş Koparal Ülker Bakır Öğütveren 《Environmental science and pollution research international》2014,21(14):8603-8609
The aim of this study is the treatment of Basic Red 29 (BR29) dye solution using hybrid iron-aluminum electrodes by electrocoagulation and electro-Fenton methods. The effect of current density, initial pH, supporting electrolyte, H2O2, and initial dye concentration on dye removal efficiency was investigated, and the best experimental conditions were obtained. Time-coarse variation of UV-Vis spectra and toxicity and chemical oxygen demand (COD) removal were also examined at the best experimental conditions. Both systems were found very successful for the removal of BR29 dye. The removal efficiency of >95 % for BR29 dye solution was reached easily in a short time. At the best experimental conditions, for the initial BR29 concentration of 100 mg/L, >95 % BR29 dye and 71.43 % COD removal were obtained after 20 and 40 min of electrolysis, respectively. Additionally, toxicity results for electro-Fenton treatment of 100 mg/L BR29 were also very promising. According to the results obtained, although electro-Fenton is more effective, both systems can be used successfully to treat textile wastewater including dyes. 相似文献