全文获取类型
收费全文 | 501篇 |
免费 | 9篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 29篇 |
废物处理 | 14篇 |
环保管理 | 90篇 |
综合类 | 94篇 |
基础理论 | 124篇 |
环境理论 | 2篇 |
污染及防治 | 101篇 |
评价与监测 | 39篇 |
社会与环境 | 14篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 5篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 17篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 15篇 |
2014年 | 18篇 |
2013年 | 34篇 |
2012年 | 21篇 |
2011年 | 32篇 |
2010年 | 28篇 |
2009年 | 30篇 |
2008年 | 31篇 |
2007年 | 29篇 |
2006年 | 29篇 |
2005年 | 23篇 |
2004年 | 18篇 |
2003年 | 12篇 |
2002年 | 17篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 8篇 |
1998年 | 12篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1958年 | 1篇 |
1943年 | 1篇 |
排序方式: 共有512条查询结果,搜索用时 24 毫秒
221.
Hans-Joachim Ballach Christine Niederée Rüdiger Wittig Ernst J. Woltering 《Environmental science and pollution research international》1995,2(4):201-206
Ozone-induced changes in ethylene production, ACC oxidase activity and the contents of ACC, MACC and free PAs were studied inPopulus nigra L. cv. Loenen with high ozone sensitivity as judged by the degree of chlorophyll degradation and premature leaf abscission. Ethylene production, ACC oxidase activity, ACC content and MACC levels were induced by the one-, two-, and three-week ozone exposure (36±9 ppb O3 for 11 hours a day). In addition, increases in PA levels, especially in spermidine, were measured in ozone treated plants. The role of free PAs and MACC synthesis as possible antisenescence reactions is discussed. 相似文献
222.
Christine Throl 《Umweltwissenschaften und Schadstoff-Forschung》2000,12(3):137-147
Zusammenfassung
Hintergrund Im Rahmen von Mess- und Monitoringprogammen werden Stoffkonzentrationen in B?den gemessen. Diese Daten müssen auch in Hinblick
auf die Auswirkungen auf terrestrische Bioz?nosen beurteilt werden. Ma?st?be zur Beurteilung gab es bisher jedoch nicht. Diese
Lücke wurde nun durch die Vorlage eines Konzepts zur Ableitung von ?kotoxikologisch begründeten Bodenqualit?tskriterien (BQK)
und dessen Anwendung für umweltrelevante Stoffe geschlossen.
Schwerpunkte Das Konzept wurde für Arsen angewendet. Hier ist der Ableitungsprozess im Detail beschrieben, von der Ethebung der Wirkungsdaten
für mikrobiologische Prozesse, Pflanzen und Bodeninvertebraten bis hin zu einem Vorschlag eines BQK für Arsen.
Methoden Der konzeptionelle Ansatz für die Ableitung von BQK wurde, nach Auswertung von nationalen und internationalen Konzepten zur
Bewertung von Substanzen auf terrestrische Lebensgemeinschaften, erarbeitet. Für die Bewerttung von Arsen wurden alle relevanten
biotischen Prozesse und Trophieebenen berücksichtigt. Desweiteren wurden Bodeneigenschaften, die einen modifizierenden Einfluss
auf die Toxizit?t von Arsen auf Biota haben, aus den vorliegenden Studien erfasst.
Ergebnisse Die Bewertung der Wirkungen von Arsen für terrestrische Lebenegemeinschaften zeigt, dass ?kotoxikologische Wirkungswerte im
Bereich der Hintergrundwerte für B?den liegen k?nnen. Indes sind Studien, in denen der Einflus von Bodeneigenschaften wie
Boden-pH, Bodentextur untersucht wurde, nur in sehr geringer Anzahl vorhanden. Daher warde das ?kotoxikologische Bodenqualit?tskriterium
für Arsen, mit 5 mg/kg Boden TG, an Hintergrundwerten für sandige B?den orientiert (“Worst-Case”). Ein Vergleich der Ergebnisse
mit ?kotoxikologisch begründeten Bodenqualit?tswerten aus Kanada, D?nemark, den Niederlanden und den Vereinigten Staaten zeigt,
dass Werte für Arsen im Mittel bei nahezu 16 mg/kg Boden TG mit einer Spannweite von 5 bis 34 mg/kg liegen. Die Unterschiede
zwischen den Werten sind ma?geblich durch die unterschiedlichen konzeptionellen Ans?tze zur Ableitung der Bodenqualit?tswerte
begründet.
Schlussfolgerungen und Ausblick Hinsichtlich direkter Wirkungen von Stoffen in B?den wird das erarbeitete Konzept für die Ableitung von BQK zum Schutz terrestrischer
Lebengemeinschaften als geeignet angesehen. Daher soll es für weitere umweltrelevante Stoffe angewendet werden. Ebenso, ist
die Bewertung der indirekten Wirkungen von Bodenschadstoffen auf V?gel und S?ugetiere, die sich von Bodeninvertebraten ern?hren,
notwendig. Auch sollen, neben Ausgleichsfaktoren zum Risikoausgleich, statistischprobabilistische Verfahren in Betracht gezogen
werden.
Online-First: 8. Mai 2000 相似文献
223.
We used population models to explore the effects of the organochlorine contaminant p,p'-DDE and fluctuations in vole availability on the population dynamics of Burrowing Owls (Athene cunicularia). Previous work indicated an interaction between low biomass of voles in the diet and moderate levels of p,p'-DDE in Burrowing Owl eggs that led to reproductive impairment. We constructed periodic and stochastic matrix models that incorporated three vole population states observed in the field: average, peak, and crash years. We modeled varying frequencies of vole crash years and a range of impairment of owl demographic rates in vole crash years. Vole availability had a greater impact on owl population growth rate than did reproductive impairment if vole populations peaked and crashed frequently. However, this difference disappeared as the frequency of vole crash years declined to once per decade. Fecundity, the demographic rate most affected by p,p'-DDE, had less impact on population growth rate than adult or juvenile survival. A life table response experiment of time-invariant matrices for average, peak, and crash vole conditions showed that low population growth under vole crash conditions was due to low adult and juvenile survival rates, whereas the extremely high population growth under vole peak conditions was due to increased fecundity. Our results suggest that even simple models can provide useful insights into complex ecological interactions. This is particularly valuable when temporal or spatial scales preclude manipulative experimental work in the field or laboratory. 相似文献
224.
Ana M. M. Viana Anne Frézard Christian Malosse Terezinha M. C. Della Lucia Christine Errard Alain Lenoir 《Chemoecology》2001,11(1):29-36
Summary. Leaf cutting ants live in symbiosis with a basidiomycete fungus that is exploited as a source of nutrients for the ant larvae.
Tests of fungus transport demonstrated that Acromyrmex subterraneus subterraneus workers discriminate concolonial fungus from alien fungus, and rejected the latter. Larvae and pupae of the ant were used
as controls. Chemical analysis of the fungus revealed a great similarity between its hydrocarbon profile and that found on
the ant brood. Experiments with lures showed that chemical extracts from the fungus are responsible for this discrimination
process. Moreover, the presence of brood inside the fungus seemed to be important for discrimination of the fungus by workers.
Resident workers accepted concolonial broodless fungus less than concolonial fungus inoculated with brood odor. Fungus seems
to acquire colonial odor passively, simply by contact with the brood. The impact of fungus volume present in the nest on closure
of the colony is discussed. We show here for the first time the importance of a symbiotic vegetal organism in colonial recognition
in social insects.
Received 14 April 2000; accepted 29 September 2000 相似文献
225.
Andrew S. Cohen Roger Bills Christine Z. Cocquyt A.G. Caljon 《Conservation biology》1993,7(3):667-677
226.
Freddie-Jeanne Richard Michael Poulsen Abraham Hefetz Christine Errard David R. Nash Jacobus J. Boomsma 《Behavioral ecology and sociobiology》2007,61(11):1637-1649
Cuticular hydrocarbon profiles are essential for nestmate recognition in insect societies, and quantitative variation in these
recognition cues is both environmentally and genetically determined. Environmental cues are normally derived from food or
nest material, but an exceptional situation may exist in the fungus-growing ants where the symbiotic fungus garden may be
an independent source of recognition compounds. To investigate this hypothesis, we quantified the chemical profiles of the
fungal symbionts of 18 sympatric colonies of Acromyrmex echinatior and Acromyrmex octospinosus and evaluated the quantitative variation of the 47 compounds in a multivariate analysis. Colony-specific chemical profiles
of fungal symbionts were highly distinct and significantly different between the two ant species. We also estimated the relative
genetic distances between the fungal symbionts using amplified fragment length polymorphism (AFLP) and correlated these with
the overall (Mahalanobis) chemical distances between the colony-specific profiles. Despite the standardized laboratory conditions,
the correlations were generally weak, but a statistically significant portion of the total variation in chemical profiles
could be explained by genetic differences between the fungal symbionts. However, there was no significant effect of ant species
in partial analyses because genetic differences between symbionts tend to coincide with being reared by different ant species.
However, compound groups differed significantly with amides, aldehydes, and methyl esters contributing to the correlations,
but acetates, alkanes, and formates being unrelated to genetic variation among symbionts. We show experimentally that workers
that are previously exposed to and fed with the fungal symbiont of another colony are met with less aggression when they are
later introduced into that colony. It appears, therefore, that fungus gardens are an independent and significant source of
chemical compounds, potentially contributing a richer and more abundant blend of recognition cues to the colony “gestalt”
than the innate chemical profile of the ants alone.
Freddie-Jeanne Richard and Michael Poulsen contributed equally to this work. 相似文献
227.
Anne Bousquet-Mélou Sophie Louis Christine Robles Stéphane Greff Sylvie Dupouyet Catherine Fernandez 《Chemoecology》2005,15(4):193-198
Summary. Biological invasions are nowadays a major problem in ecology. Allelopathy has been shown to be involved in such invasions,
but this mechanism has been little studied in France. The objectives of this study were to evaluate the allelopathic potential
of Medicago arborea, an invasive species in the French Mediterranean region. Foliar extracts were tested on three target species (Lactuca sativa, Lepidium sativum and Linum strictum). We showed that Medicago arborea has high allelopathic potential to affect the growth and germination of other species. Yellow flax (Linum strictum), native to the invaded area, was the most sensitive of the tested plant species to foliar extracts of Medicago arborea. Our study pointed out the role of allelopathy in processes leading to biological invasion, and more generally in population
dynamics. 相似文献
228.
Naspinski C Lingenfelter R Cizmas L Naufal Z He LY Islamzadeh A Li Z Li Z McDonald T Donnelly KC 《Environment international》2008,34(7):988-993
Settled house dust can be a source of human exposure to toxic polycyclic aromatic hydrocarbons (PAHs) through non-dietary ingestion and dermal contact. Information regarding the concentrations of various contaminants in house dust would be useful in estimating the risk associated with exposure to these compounds. This study reports on the surface loading, variability and distribution of PAHs in settled house dust collected from homes in three locations: Sumgayit, Azerbaijan; Shanxi Province, China; and southern Texas, United States. The highest PAH floor surface loadings were observed in China, followed by Azerbaijan and Texas. Median concentrations of high molecular weight (four ring and larger) PAHs ranged from a low of 0.11 microg/m(2) in Texas, to 2.9 microg/m(2) in Azerbaijan and 162 microg/m(2) in China. These trends in total surface loading and relative carcinogenicity indicate that the risk of health effects from exposure to PAHs in house dust is highest in the Chinese population and lowest in the Texas population. As anticipated, variability among dust samples from different houses within the same region was high, with coefficients of variation greater than 100%. Alkylated PAHs comprised 30-50% of the total mass of PAHs. Based on a comparison of the composition of specific components, PAHs in China and Azerbaijan were determined to be derived mainly from combustion sources rather than from unburned fossil fuels such as petroleum. These results, coupled with ongoing investigation of appropriate PAH exposure biomarkers in humans, will guide future efforts to identify ways to reduce exposures in the study areas. 相似文献
229.
Evelyn Vingilis Zümrüt Yıldırım-Yenier Larissa Vingilis-Jaremko Christine Wickens Jane Seeley Judy Fleiter 《Traffic injury prevention》2017,18(6):606-615
Objective: Entry of terms reflective of extreme risky driving behaviors into the YouTube website yields millions of videos. The majority of the top 20 highly subscribed automotive YouTube websites are focused on high-performance vehicles, high speed, and often risky driving. Moreover, young men are the heaviest users of online video sharing sites, overall streaming more videos, and watching them longer than any other group. The purpose of this article is to review the literature on YouTube videos and risky driving.Methods: A systematic search was performed using the following specialized database sources—Scopus, PubMed, Web of Science, ERIC, and Google Scholar—for the years 2005–2015 for articles in the English language. Search words included “YouTube AND driving,” “YouTube AND speeding,” “YouTube AND racing.”Results: No published research was found on the content of risky driving videos or on the effects of these videos on viewers. This literature review presents the current state of our published knowledge on the topic, which includes a review of the effects of mass media on risky driving cognitions; attitudes and behavior; similarities and differences between mass and social media; information on the YouTube platform; psychological theories that could support YouTube's potential effects on driving behavior; and 2 examples of risky driving behaviors (“sidewalk skiing” and “ghost riding the whip”) suggestive of varying levels of modeling behavior in subsequent YouTube videos.Conclusions: Every month about 1 billion individuals are reported to view YouTube videos (ebizMBA Guide 2015) and young men are the heaviest users, overall streaming more YouTube videos and watching them longer than women and other age groups (Nielsen 2011). This group is also the most dangerous group in traffic, engaging in more per capita violations and experiencing more per capita injuries and fatalities (e.g., Parker et al. 1995; Reason et al. 1990; Transport Canada 2015; World Health Organization 2015). YouTube also contains many channels depicting risky driving videos. The time has come for the traffic safety community to begin exploring these relationships. 相似文献
230.
/ An index of upland wildlife habitat was developed to investigate patterns and changes in habitat over time, using four years (1920, 1940, 1964, 1987) and the state of Illinois as an example. The index was composed of two subdivisions that described, at the county level, the quantity of wildlife habitat and a third subdivision that described farming disturbances that impacted the quality of the habitat. Data came from the US Census of Agriculture. The first subdivision that reflected quantity of habitat was called the wildlife habitat subdivision and was the sum of percentage woodland on farms, percentage farmland in nonrow crops, and percentage farmland in set-aside programs. The second subdivision that reflected the quantity of habitat was termed the soil-related features subdivision and was the sum of the percentage of farmland that was not highly erodible, the percentage of farmland in soil-protecting crops, and the percentage of farmland in conservation tillage. The third subdivision, reflecting the quality of the habitat, was the farming disturbance subdivision and was the sum of the percentage of grazing and the percentage of land on which fertilizers, pesticides, and herbicides were applied. Overall, major decreases occurred between 1920 and 1987 in the subdivisions reflecting the quantity of wildlife habitat and a major increase occurred in the subdivision associated with farming disturbance, reflecting the intensification of agriculture in the state. However, there was variability throughout the state, with some counties being more favorable to wildlife (as measured by the subdivisions) than others. Most of the changes within the state for the subdivisions reflecting quantity of upland wildlife habitat occurred during 1940 while changes in the farming disturbance subdivision (reflecting habitat quality) occurred in 1964. By 1987, the western and southern parts of Illinois were the most favorable for wildlife as reflected in all three subdivisions. Upland wildlife harvest indices were related to the subdivisions in 1964 and 1987, when harvest indices were available. Cottontail and northern bobwhite harvests were higher in counties with higher amounts of the wildlife habitat subdivision in both years. Cottontail harvest was also higher in counties with lower levels of the farming disturbance subdivision in 1964 and higher levels of soil-related features subdivision in 1987. Indices at the county level have the potential to be used in a multiscale analysis to investigate the impact of policy changes on large-scale areas of the Midwest and to develop regional perspectives of the impacts of agriculture on upland wildlife and their habitats.KEY WORDS: Upland wildlife; Habitat; Agriculture; Illinois 相似文献