全文获取类型
收费全文 | 185篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 9篇 |
环保管理 | 22篇 |
综合类 | 52篇 |
基础理论 | 32篇 |
环境理论 | 1篇 |
污染及防治 | 40篇 |
评价与监测 | 10篇 |
社会与环境 | 14篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 2篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 13篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 12篇 |
2008年 | 11篇 |
2007年 | 16篇 |
2006年 | 6篇 |
2005年 | 15篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1975年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1966年 | 2篇 |
1963年 | 1篇 |
1960年 | 1篇 |
1958年 | 1篇 |
1956年 | 1篇 |
1952年 | 1篇 |
排序方式: 共有188条查询结果,搜索用时 15 毫秒
21.
Ingrid Jüttner P. James Chimonides Steve J. Ormerod 《Environmental monitoring and assessment》2010,162(1-4):47-65
Periphytic diatoms were studied to evaluate the water quality of a newly created lake, formed by the enclosure of the formerly tidal Cardiff Bay (Wales, UK), and the effects of two inflowing rivers which drain densely populated and industrialised catchments. Seven sites in Cardiff Bay and two locations on the inflowing rivers were monitored for diatoms and water chemistry over 2 years. Water quality was assessed using a revised UK trophic diatom index (TDI) and new methods to determine ecological quality ratios and ecological status classes as required by the EU Water Framework Directive. Diatom assemblages reflected spatiotemporal variations in environmental conditions between the rivers and Cardiff Bay and within the bay. In the bay, diatoms reflected differences in river quality and possibly local pollution in certain areas of the lake. High values of the TDI indicated eutrophic to hypertrophic conditions in both rivers and in the bay and diatoms indicated poor ecological status. 相似文献
22.
Professor Dr Gerhard Bernaschek Akgun Yildiz Aytug Kolankaya Ingrid Stuempflen Josef Deutinger 《黑龙江环境通报》1995,15(11):995-1000
Between 1990 and 1993, 166 cases underwent cordocentesis and were followed for at least the following 4 weeks in the Prenatal Diagnosis and Therapy Centre of Vienna University. The indications for the procedure were structural malformations in 46·4 per cent of the cases, other high-risk diagnoses in 48·8 per cent, and maternal age over 35 years in only 4·8 per cent. We investigated retrospectively all cases of complications resulting in fetal loss or preterm labour. Abortion, intrauterine fetal death, chorioamnionitis, and preterm delivery occurred in 0·6, 5·4, 0·6 and 9·0 per cent of these cases, respectively, adding up to a total of 26 cases (15·7 per cent). Although this rate looks relatively high, 20 of the 26 cases had already displayed signs implying a complicated prognosis. Neither maternal age, gestational age, number of attempts, nor placental location correlated with fetal loss or preterm delivery. Significantly higher rates of fetal loss or preterm delivery were observed when cordocentesis was performed in cases diagnosed as duodenal/intestinal stenosis or hydrops–ascites–hydrothroax/hygroma colli (P=0·0488 and P=0·0005). The frequency of complications did not decrease as the experience of the operators increased. 相似文献
23.
24.
25.
26.
Levels of perfluorochemicals in water samples from Catalonia,Spain: is drinking water a significant contribution to human exposure? 总被引:2,自引:0,他引:2
Ericson I Nadal M van Bavel B Lindström G Domingo JL 《Environmental science and pollution research international》2008,15(7):614-619
Background, aim, and scope In recent years, due to a high persistence, biomagnification in food webs, presence in remote regions, and potential toxicity,
perfluorochemicals (PFCs) have generated a considerable interest. The present study was aimed to determine the levels of perfluorooctane
sulfonate (PFOS), perfluorooctanoic acid (PFOA), and other PFCs in drinking water (tap and bottled) and river water samples
from Tarragona Province (Catalonia, Spain).
Materials and methods Municipal drinking (tap) water samples were collected from the four most populated towns in the Tarragona Province, whereas
samples of bottled waters were purchased from supermarkets. River water samples were collected from the Ebro (two samples),
Cortiella, and Francolí Rivers. After pretreatment, PFC analyses were performed by HPLC-MS. Quantification was done using
the internal standard method, with recoveries between 68% and 118%.
Results In tap water, PFOS and PFOA levels ranged between 0.39 and 0.87 ng/L (0.78 and 1.74 pmol/L) and between 0.32 and 6.28 ng/L
(0.77 and 15.2 pmol/L), respectively. PFHpA, PFHxS, and PFNA were also other detected PFCs. PFC levels were notably lower
in bottled water, where PFOS could not be detected in any sample. Moreover, PFHpA, PFHxS, PFOA, PFNA, PFOS, PFOSA, and PFDA
could be detected in the river water samples. PFOS and PFOA concentrations were between <0.24 and 5.88 ng/L (<0.48 and 11.8 pmol/L)
and between <0.22 and 24.9 ng/L (<0.53 and 60.1 pmol/L), respectively.
Discussion Assuming a human water consumption of 2 L per day, the daily intake of PFOS and PFOA by the population of the area under evaluation
was calculated (0.78–1.74 and 12.6 ng, respectively). It was found that drinking water might be a source of exposure to PFCs
as important as the dietary intake of these pollutants.
Conclusions The contribution of drinking water (tap and bottled) to the human daily intake of various PFCs has been compared for the first
time with data from dietary intake of these PFCs. It was noted that in certain cases, drinking water can be a source of exposure
to PFCs as important as the dietary intake of these pollutants although the current concentrations were similar or lower than
those reported in the literature for surface water samples from a number of regions and countries.
Recommendations and perspectives Further studies should be carried out in order to increase the knowledge of the role of drinking water in human exposure to
PFCs. 相似文献
27.
Effective recreation resource management relies on understanding visitor perceptions and behaviors. Given current and increasing
pressures on water resources, understanding crowding evaluations seems important. Beyond crowding, however, variables that
possibly relate to or influence crowding are of interest and in particular, place attachment and experience-use history (EUH).
As EUH is related to place attachment and likely affects crowding, this study explored the moderating effect of place attachment
dimensions on the relationships between EUH and visitor crowding evaluations. Water based recreationists at a U.S. Army Corps
of Engineers site were contacted onsite and asked questions related to experience-use history, crowding evaluations, place
attachment, and activity participation. Anglers and campers at the site identified similar crowding perceptions and place
attachments. Only one of eight models tested revealed a moderating effect. Specifically, place identity moderated the relationship
between the total times visited in the past twelve months and expected crowding among anglers. As such, the quest continues
to understand the relationship among these important variables. 相似文献
28.
29.
30.
Hans-Ulrich Schnitzler Elisabeth K. V. Kalko Ingrid Kaipf Alan D. Grinnell 《Behavioral ecology and sociobiology》1994,35(5):327-345
When hunting for fish Noctilio leporinus uses several strategies. In high search flight it flies within 20–50 cm of the water surface and emits groups of two to four echolocation signals, always containing at least one pure constant frequency (CF) pulse and one mixed CF-FM pulse consisting of a CF component which is followed by a frequency-modulated (FM) component. The pure CF signals are the longest, with an average duration of 13.3 ms and a maximum of 17 ms. The CF component of the CF-FM signals averages 8.9 ms, the FM sweeps 3.9 ms. The CF components have frequencies of 52.8–56.2 kHz and the FM components have an average bandwidth of 25.9 kHz. A bat in high search flight reacts to jumping fish with pointed dips at the spot where a fish has broken the surface. As it descends to the water surface the bat shows the typical approach pattern of all bats with decreasing pulse duration and pulse interval. A jumping fish reveals itself by a typical pattern of temporary echo glints, reflected back to the bat from its body and from the water disturbance. In low search flight N. leporinus drops to a height of only 4–10 cm, with body parallel to the water, legs extended straight back and turned slightly downward, and feet cocked somewhat above the line of the legs and poised within 2–4 cm of the water surface. In this situation N. leporinus emits long series of short CF-FM pulses with an average duration of 5.6 ms (CF 3.1 and FM 2.6) and an average pulse interval of 20 ms, indicating that it is looking for targets within a short range. N. leporinus also makes pointed dips during low search flight by rapidly snapping the feet into the water at the spot where it has localized a jumping fish or disturbance. In the random rake mode, N. leporinus drops to the water surface, lowers its feet and drags its claws through the water in relatively straight lines for up to 10m. The echolocation behavior is similar to that of high search flight. This indicates that in this hunting mode N. leporinus is not pursuing specific targets, and that raking is a random or statistical search for surface fishes. When raking, the bat uses two strategies. In directed random rake it rakes through patches of water where fish jumping activity is high. Our interpretation is that the bat detects this activity by echolocation but prefers not to concentrate on a single jumping fish. In the absence of jumping fish, after flying for several minutes without any dips, N. leporinus starts to make very long rakes in areas where it has hunted successfully before (memory-directed random rake). Hunting bats caught a fish approximately once in every 50–200 passes through the hunting area. 相似文献