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101.
It has been argued that strategies to manage natural areas important for tourism and recreation should integrate an understanding
of tourist preferences for specific natural features. However, the accuracy of tourist recalled perceptions of environmental
attributes, which are usually derived from post hoc surveys and used to establish management priorities, is currently unmeasured.
We tested the validity of the relationship between tourist-stated preferences and actual condition of coral reefs around the
Caribbean island of Bonaire. Using standardized questionnaires, we asked 200 divers to select their most and least favorite
dive sites and the attributes that contributed to that selection. We also carried out ecological surveys at 76 of the 81 dives
sites around the island to assess the actual conditions of the attributes indicated as important for site selection. Fish-
and coral-related attributes were key features affecting dive enjoyment. In general, divers appeared to be able to perceive
differences between sites in the true condition of biological attributes such as fish species richness, total number of fish
schools, live coral cover, coral species richness, and reef structural complexity, although men and women divers differed
in their ability to perceive/recall some of the attributes. Perceived differences in environmental attributes, such as surface
conditions, underwater current, and the likelihood of encountering rare fish and sea turtles, were not empirically validated.
The fact that divers perceive correctly differences in the condition of some of the key biological attributes that affect
dive enjoyment reinforces the need to maintain overall reef condition at satisfactory levels. However, variation in accuracy
of perceptions owing to demographic factors and attribute type suggests the need for caution when using public perceptions
to develop environmental management strategies, particularly for coral reefs. 相似文献
102.
Extra-pair paternity in the monogamous Alpine marmot revealed by nuclear DNA microsatellite analysis 总被引:8,自引:0,他引:8
Benoît Goossens Laurent Graziani Lisette P. Waits Etienne Farand Séverine Magnolon Jacques Coulon Marie-Claude Bel Pierre Taberlet Dominique Allainé 《Behavioral ecology and sociobiology》1998,43(4-5):281-288
The genetic parentage and pedigrees of 35 litters from 12 family groups of monogamous Alpine marmot (Marmota marmota) in the French Alps were analyzed using six hypervariable sequence repeat nuclear loci (microsatellites). All of the members
of these family groups were sampled during a 5-year period. Hairs taken directly from animals served as a source of DNA for
amplification of the loci. Our results indicate that the genetic mating system of the Alpine marmot is quite different from
a strictly monogamous breeding system. Extra-pair paternity occurred in 11 of the 35 litters (31.4%). Of the 134 juveniles
typed, 26 (19.4%) could be attributed to extra-pair copulation (EPC). We examine hypotheses which could explain the evolution
of EPC and discuss the different patterns of extra-pair mating.
Received: 11 July 1997 / Accepted after revision: 23 May 1998 相似文献
103.
104.
Jaroslav Hynt Miloslav imek Petr Br
ek Sren O. Petersen 《Agriculture, ecosystems & environment》2007,120(2-4):269-279
Cattle overwintering areas common in central Europe may represent significant point sources of the important greenhouse gases, nitrous oxide (N2O) and carbon dioxide (CO2). A 2-year field study was carried out in order to estimate the emissions of N2O and CO2 from soil in a cattle overwintering area located in the southwest of the Czech Republic. The measurements were performed at three sampling locations along a gradient of animal impact (severe, moderate, slight) to test the hypothesis that emissions of CO2 and N2O are positively related to the degree of impact. In addition to CO2 and N2O fluxes determined by using non-vented manual closed chambers, soil mineral nitrogen (NH4+ and NO3−), pH and temperature were determined to assess their regulatory role and impact on gas fluxes. The overwintering area was about 4 ha and it had been used for overwintering of about 90 cows since 1995. Deposition of animal excreta resulted in a significant accumulation of nitrogen in the soil during winter, but most of the N2O was emitted during a few short periods in spring and/or in late autumn. Maximum N2O fluxes of up to 2.5 mg N2O-N m−2 h−1 were recorded at the most impacted location near the animal house, where the highest concentrations of soil mineral nitrogen also occurred. The emissions of CO2 showed a completely different pattern to those of N2O, being correlated with soil temperature; the highest emissions thus occurred in June–July, while very low fluxes were found in winter. Emission values ranged from about 0 to 700 mg C-CO2 m−2 h−1. Furthermore, the effect of animal impact on CO2 emissions was opposite to that on N2O fluxes, as the highest CO2 fluxes were mostly recorded at the least impacted location, where respiration of plants most likely increased overall CO2 production. The results show that cattle overwintering areas are important sources of greenhouse gases, including N2O and CO2. Fluxes of these two gases are, however, differently distributed over the year, which also suggests that they are controlled by different environmental and soil factors. 相似文献
105.
Broz J Grabic R Kilián J Lojkásek M Marklund S Ocelka T Pekárek V Pribyl J Tydlitát V Výska J 《Chemosphere》2000,41(12):1948-1911
The effect of synthetic and mineral oils on the formation of polyaromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in emissions from a spark ignition engine was studied on a Skoda Favorit engine fueled with leaded gasoline. The test cycle simulated urban traffic conditions on a chassis dynamometer, in accordance with the ECC 83.00 test. The data for selected PAHs as well as PCDDs, PCDFs, and PCBs congener profiles are presented. PCDD/Fs emissions for an unused oil and the oil after 10000-km operation varied from 300 to 2000 fmol/m3, PCBs emissions from 75 to 178 pmol/m3, and PAHs emissions from 150 to 420 microg/m3. The content of PCBs in oils varied from 2 to 920 mg/kg. 相似文献
106.
Kammann U Lang T Vobach M Wosniok W 《Environmental science and pollution research international》2005,12(3):140-145
Goal, Scope and Background Ethoxyresorufin-O-deethylase (EROD) is a well-accepted marker for biological effects in fish and is, therefore, part of numerous monitoring programmes. EROD activity was measured in livers of dab (Limanda limanda) from the German Bight (North Sea) from 1995 to 2003. The aim of the present long-term study was (a) time trend monitoring of EROD activity of dab from the German Bight and (b) to elucidate the needs for a successful application of EROD activity as an early warning system.
Methods. EROD activities were determined fluorimetrically in dab liver microsomes, using resorufin as an external standard. The limit of detection (LD) and the limit of quantification (LQ) were calculated. Results were referred to protein concentrations.
Results and Discussion. EROD activities of 610 female dab caught in different seasons between January 1995 and August 2003 were analyzed individually. Activities varied from 〈 LD to 1768 pmol/(min mg protein) and showed an annual cycle as well as significant differences between the years. Highest EROD activities were observed in early summer and lowest activities during the winter period. In autumn 2002, significantly elevated EROD activities were detected, possibly related to effects of the River Elbe flood event. Two scenarios with different EROD baseline data are presented to discuss the prerequisites for the use of EROD as a monitoring tool. The comparison of these scenarios underlines the importance of appropriate season-specific baseline data.
Conclusion. The use of EROD as an early warning tool for contaminant effects in dab in the German Bight has different prospects during the year, because, due to the high background variability, elevated EROD activities are less easy to detect in spring/summer than during the remaining times of the year.
Recommendation and Outlook. The availability of site-specific data on the EROD baseline level, its random variation and its annual cycle is a necessary prerequisite for monitoring. If monitoring is to be carried out only for a limited time period of the year, a season with low background variability in EROD activity (autumn) should be chosen to avoid the need for a compensation of the temperature-triggered shift in sexual cycles and the resulting changes in EROD activity. 相似文献
107.
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
108.
Phytoplankton community structure and primary production in small intertidal estuarine-bay ecosystem (eastern English Channel,France) 总被引:1,自引:0,他引:1
From May 2002 to October 2003, a fortnightly sampling programme was conducted in a restricted macrotidal ecosystem in the
English Channel, the Baie des Veys (France). Three sets of data were obtained: (1) physico-chemical parameters, (2) phytoplankton community structure illustrated
by species composition, biovolume and diversity, and (3) primary production and photosynthetic parameters via P versus E curves. The aim of this study was to investigate the temporal variations of primary production and photosynthetic parameters
in this bay and to highlight the potential links with phytoplankton community structure. The highest level of daily depth-integrated
primary production Pz (0.02–1.43 g C m−2 d−1) and the highest maximum photosynthetic rate P
B
max (0.39–8.48 mg C mg chl a
−1 h−1) and maximum light utilization coefficient αB [0.002–0.119 mg C mg chl a
−1 h−1 (μmol photons m−2 s−1)] were measured from July to September. Species succession was determined based on biomass data obtained from cell density
and biovolume measurements. The bay was dominated by 11 diatoms throughout the year. However, a Phaeocystis globosa bloom (up to 25 mg chl a m−3, 2.5 × 106 cells l−1) was observed each year during the spring diatom bloom, but timing and intensity varied interannually. Annual variation of
primary production was due to nutrient limitation, light climate and water temperature. The seasonal pattern of microalgal
succession, with regular changes in composition, biovolume and diversity, influenced the physico-chemical and biological characteristics
of the environment (especially nutrient stocks in the bay) and thus primary production. Consequently, investigation of phytoplankton
community structure is important for developing the understanding of ecosystem functioning, as it plays a major role in the
dynamics of primary production. 相似文献
109.
Yanick Gendreau Steeve D. Côté Marco Festa-Bianchet 《Behavioral ecology and sociobiology》2005,58(3):237-246
Little is known about maternal effects on post-weaning development, yet they may be important because maternal care could have long-term consequences only evident when offspring approach adulthood. We have assessed the effects of maternal age, current reproduction (presence of a kid of the year) and social rank on the body mass, horn length and social rank of 1- and 2-year-old mountain goats (Oreamnos americanus). Maternal reproductive status and social rank did not affect the mass or horn length of either yearlings or 2-year-olds. Maternal age was positively correlated with yearling body mass for males but not females. We could not detect any maternal age effects on body mass of 2-year-olds. Maternal age and spring forage quality were positively correlated with horn length of yearlings of both sexes, but not of 2-year-olds. Juvenile females showed compensatory growth in mass between 1 and 2 years of age, but males did not. Neither sex showed compensatory growth in horn length. None of the maternal characteristics we examined directly affected the social rank of juveniles, which increased with body mass. Social rank in female mountain goats seems to be established early in life and maintained to adulthood. By affecting yearling development, maternal age could affect the reproductive success of males. 相似文献
110.
Behdin Nowrouzi Basem Gohar Behnam Nowrouzi-Kia Martyna Garbaczewska Olena Chapovalov Étienne Myette-Côté 《International journal of occupational safety and ergonomics》2016,22(3):360-366
Purpose. The purpose of this particular study was to test a newly created instrument in describing the facilitators and barriers to occupational health and safety in small and medium-sized enterprises (SMEs) in Ontario, Canada. Methods. A cross-sectional design was used to identify the occupational health and safety culture of SMEs in public and private sectors in Ontario. Results. A total of 153 questionnaires were completed. The majority of respondents were female (84%) with a mean age of 49.8 years (SD 10.6). Seventy-four percent were supervisors. Seventy percent of respondents were from the private sector while 30% derived from the public sector including healthcare, community services, and non-profit organizations. Further, conducting regular external safety inspections of the workplace was found to be statistically associated with a safe work environment 2.88 95% CI [1.57, 5.27]. Conclusions. Strategies and training opportunities that focus on how to adapt occupational health and safety legislation to the nature and diversity of SMEs are recommended. Furthermore, employers may use such information to improve safety in their SMEs, while researchers can hopefully use such evidence to develop interventions that are applicable to meeting the occupational health and safety needs of SMEs. 相似文献