全文获取类型
收费全文 | 251篇 |
免费 | 4篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 53篇 |
环保管理 | 9篇 |
综合类 | 47篇 |
基础理论 | 39篇 |
环境理论 | 3篇 |
污染及防治 | 83篇 |
评价与监测 | 7篇 |
社会与环境 | 18篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 7篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 22篇 |
2012年 | 10篇 |
2011年 | 18篇 |
2010年 | 12篇 |
2009年 | 25篇 |
2008年 | 18篇 |
2007年 | 22篇 |
2006年 | 12篇 |
2005年 | 14篇 |
2004年 | 12篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1974年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有273条查询结果,搜索用时 15 毫秒
141.
142.
Hesitation behaviour of hoverflies Sphaerophoria spp. to avoid ambush by crab spiders 总被引:1,自引:0,他引:1
Pollinators possess several antipredator adaptations that minimise predation risk during foraging. In addition to morphological adaptations, hoverflies might have behavioural antipredator adaptations. We conducted three field experiments to investigate whether the "hesitation behaviour" of hoverflies Sphaerophoria spp., moving backwards and forwards in front of a flower, is effective in avoiding ambush predators on flowers. First, we compared the behaviour of different flower visitors, including several bees and other hoverflies, with Sphaerophoria spp. behaviour. Only Sphaerophoria spp. exhibited the hesitation behaviour in front of flowers. The flight behaviour was observed more frequently before landing on flowers than on leaves. Second, we investigated rejection by Sphaerophoria spp. to artificially placed corpses of the crab spider Thomisus labefactus. The rejection rate of flowers with a crab spider placed on or under it was significantly higher than that of non-treated flowers. Moreover, the presence of a spider on the flower decreased the number of hesitation displays, compared with non-treated flowers. Finally, to determine whether hesitation behaviour could be a consequence of floral assessment, we investigated hoverfly rejection of previously foraged flowers. Sphaerophoria spp. did not reject flowers that had been visited by the same individual or conspecifics within 3 min. We suggest that hesitation behaviour may be adaptive, enabling assessment of predation risk and hence avoiding ambush predators on flowers. 相似文献
143.
An estrogen receptor (ER)/androgen receptor (AR) ligand competitive binding assay (ER/AR-binding assay) and chemical analyses
were used to evaluate the endocrine disrupting chemicals (EDCs) behavior of two municipal wastewater treatment plants (WWTPs) (K
and S). In the influents, estrone (E1), androsterone (A), androstenedione (AD), BPA (bisphenol A), NP (nonylphenol) and daidzein (DZ)
were detected in high amounts with subsequent 24 h-average concentrations of 350, 1000, 29, 1300, 3900, and 5700 ng/L in K-WWTP
and of 310, 620, 59, 1600, 2600, and 8400 ng/L in S-WWTP. The estrogenic (androgenic) activity as 17 -estradiol (E2) equivalents
(EEQ) or testosterone (Te) equivalents (TEQ) was consequently 620 ng E2/L (570 ng Te/L) and 580 ng E2/L (800 ng Te/L) for the
two WWTPs. The removal e ciencies of the above mentioned sole target chemicals were 51%–100% for K-WWTP and 55.6%–100%
for S-WWTP. The removal e ciencies of EEQ were about 73% for both WWTPs, while the removal e ciencies of TEQ were 62.1%
for K-WWTP and 98.4% for S-WWTP. In addition, chemical-derived EEQ were about 1.2%–52.4% of those by ER-binding assay for
K-WWTP and the corresponding ratios were 1.3%–83.3% for S-WWTP, while chemical derived TEQ were less than 3% of values
measured by the AR-binding assay for both WWTPs. 相似文献
144.
145.
146.
The use of heterospecific scent marks by the sweat bee <Emphasis Type="Italic">Halictus aerarius</Emphasis> 总被引:2,自引:1,他引:1
To forage effectively amongst flowers, some bee species utilize olfactory cues left by previous visitors in addition to direct
assessment of visual cues to identify rewarding flowers. This ability can be more advantageous if the bees can recognize and
use scent marks left by heterospecifics, not just marks left by members of their own species. We conducted field experiments
to investigate whether the sweat bee Halictus aerarius avoids visiting flowers of trailing water willow Justicia procumbens emptied by other bee species. We found that H. aerarius rejected the flowers visited by both heterospecifics and conspecifics. They also rejected visited flowers artificially replenished
with nectar. Our results demonstrate that social bees outside the Apidae can detect marks left on flowers by heterospecifics
but that (on this plant species) they are unable to discriminate against flowers by directly detecting nectar volume. H. aerarius exhibited different rejection rates according to the identity of the previous bee species. We suggest that the frequency
of rejection responses may depend on the amount of chemical substances left by the previous bee. In general, the use of scent
marks left by previous visitors is almost certainly advantageous, enabling foragers to avoid flowers with depleted nectar
levels and thereby improving their foraging efficiency. 相似文献
147.
Jun Yamamoto Miyuki Hirose Tetsuya Ohtani Katashi Sugimoto Kazue Hirase Nobuo Shimamoto Tsuyoshi Shimura Natsumi Honda Yasuzumi Fujimori Tohru Mukai 《Marine Biology》2008,153(3):311-317
The fate of the giant jellyfish Nemopilema nomurai after death was examined in the southwest Sea of Japan. The density of dead jellyfish was greater than that of live animals.
The dead animals are heavier than the Japan Sea Proper Water which occurs deeper than 200 m, suggesting that dead jellyfish
sink to the sea floor. The sea floor survey, conducted with a towed video tape recorder (VTR) monitoring system between mid
September and mid October, observed a total of 138 jellyfish during 28 of 29 operations. The density of carrion ranged between
0.2 and 5.1 individuals/1,000 m2 (mean ± SE = 1.1 ± 0.2). Ophiuroids occurred abundantly at 23 jellyfish carcasses and a sea anemone was observed attached
to five carcasses. The VTR surveys confirmed that carrion sinks to the sea floor not only during the winter, the normal end
of life for medusae, but also during the fall. A trap survey baited with medusae was also employed, and four different species
were sampled with the traps: the snow crab (Chionoecetes opilio), a shrimp (Pandalopsis japonica), the ivory shell (Buccinum striatissimum) and an ophiuroid (Ophiura sarsii). Much of the trap bait remained (49–68% weight-mean = 60.3%) during the 23 h soak-time, and the reduction in weight was
greater than that observed by bacterial decomposition, suggesting benthic animals consume dead organisms. The present study
indicates that dead N. nomurai sink to the sea floor continuously and were subsequently consumed by benthic scavengers. 相似文献
148.
A simple technology for phosphate (P i ) recovery has been developed using a bifunctional adsorption–aggregation agent. The bifunctional agent was prepared by soaking calcium silicates in hydrochloric acid solution. Importantly, recyclable calcium silicates were available almost free of charge from the cement industry and also from the steel industry. The acid treatment was essential not only for enhancing the ability of calcium silicates to remove P i from aqueous solution but also for enabling the high settleability of removed P i . On-site experiments using a mobile plant showed that approximately 80% P i could be recovered from anaerobic sludge digestion liquor at a wastewater treatment plant. This technology has the potential to offer a simple, compact service for recycling P i from wastewater to farmland in rural areas. 相似文献
149.
Thomas Dominguez Johanna Aurell Brian Gullett Robert Eninger Dirk Yamamoto 《Journal of Material Cycles and Waste Management》2018,20(2):902-913
Emissions from open burning of military food waste and ration packaging compositions were characterized in response to health concerns from open burning disposal of waste, such as at military forward operating bases. Emissions from current and prototype Meals, Ready-to-Eat (MREs), and material options for their associated fiberboard packaging were quantified to assess contributions of the individual components. MREs account for 67–100% of the particulate matter (PM), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated dibenzo-p-dioxins and -furans (PCDDs/PCDFs) emissions when burned in unison with the current fiberboard container and liner. The majority of the particles emitted from these burns are of median diameter 2.5 µm (PM2.5). Metal emission factors were similar regardless of waste composition. Measurements of VOCs and PAHs indicate that targeted replacement of MRE components may be more effective in reducing emissions than variation of fiberboard-packaging types. Despite MRE composition variation, equivalent emission factors for PM, PAH, VOC, and PCDD/PCDF were seen. Similarly, for fiberboard packaging, composition variations exhibited essentially equivalent PM, PAH, VOC, and PCDD/PCDF emission factors amongst themselves. This study demonstrated a composition-specific analysis of waste burn emissions, assessing the impact of waste component substitution using military rations. 相似文献
150.
Takashi Yamamoto Akiko Kida Yukio Noma Atsushi Terazono Shin-ichi Sakai 《Journal of Material Cycles and Waste Management》2018,20(1):214-222
Appropriate treatment of asbestos waste is a significant problem. In Japan, inertization of asbestos-containing waste by novel techniques approved by the Ministry of the Environment is now promoted. A quantitative method of testing with high sensitivity to the asbestos levels present in the inertization products is required for the approval process, but many testing methods are only qualitative. Thus, we have developed an evaluation method for asbestos in inertized products, consisting of the extraction of fibers from inertized products and determination of fiber number concentration by transmission electron microscopy. We adopted this testing method to evaluate thermally treated asbestos. It was found that fiber number concentrations of thermally treated asbestos decreased with increased treatment temperature, and were below the environmental level (102 Mf/g) at more than 1000 °C for chrysotile and crocidolite and more than 1400 °C for amosite and other amphibole forms of asbestos. 相似文献