全文获取类型
收费全文 | 2010篇 |
免费 | 32篇 |
国内免费 | 15篇 |
专业分类
安全科学 | 56篇 |
废物处理 | 73篇 |
环保管理 | 309篇 |
综合类 | 371篇 |
基础理论 | 492篇 |
环境理论 | 4篇 |
污染及防治 | 512篇 |
评价与监测 | 144篇 |
社会与环境 | 90篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 31篇 |
2022年 | 29篇 |
2021年 | 28篇 |
2020年 | 28篇 |
2019年 | 28篇 |
2018年 | 51篇 |
2017年 | 61篇 |
2016年 | 54篇 |
2015年 | 57篇 |
2014年 | 59篇 |
2013年 | 143篇 |
2012年 | 88篇 |
2011年 | 132篇 |
2010年 | 83篇 |
2009年 | 100篇 |
2008年 | 108篇 |
2007年 | 119篇 |
2006年 | 93篇 |
2005年 | 80篇 |
2004年 | 75篇 |
2003年 | 75篇 |
2002年 | 80篇 |
2001年 | 34篇 |
2000年 | 27篇 |
1999年 | 19篇 |
1998年 | 19篇 |
1997年 | 23篇 |
1996年 | 20篇 |
1995年 | 23篇 |
1994年 | 25篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 15篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 17篇 |
1987年 | 12篇 |
1986年 | 15篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1974年 | 6篇 |
1955年 | 5篇 |
1954年 | 8篇 |
排序方式: 共有2057条查询结果,搜索用时 125 毫秒
391.
Boutillier Sophie Fourmentin Sophie Laperche Blandine 《Environmental Chemistry Letters》2022,20(2):1017-1033
Environmental Chemistry Letters - Since its discovery in the late eighteenth century and mass production in the early twentieth century, titanium dioxide has been used in a wide range of... 相似文献
392.
Novotna Kruzikova Kamila Siroka Zuzana Jurajda Pavel Harustiakova Danka Smolikova Zdenka Kubicek Martin Svobodova Zdenka 《Environmental science and pollution research international》2022,29(12):17394-17405
Environmental Science and Pollution Research - This study focused on the total mercury content in fish from seven drinking-water reservoirs located in the Morava River Basin: Bojkovice, Boskovice,... 相似文献
393.
394.
Nuxia L. Espinoza-Fuenzalida Martin Thiel Enrique Dupre J. Antonio Baeza 《Marine Biology》2008,155(6):623-635
Sexual systems vary considerably among caridean shrimps and while most species are gonochoric, others are described as sequential
protandric hermaphrodites or simultaneous hermaphrodites with an early male phase. At present, there is confusion about the
sexual system exhibited by several species mostly because those studies attempting to reveal their sexual system draw inferences
solely from the distribution of the sexes across size classes. Here we investigated the sexual system of the shrimp Hippolyte williamsi from Chile to determine if the species is protandric or gonochoric with sexual dimorphism (males smaller than females). Morphological
identification and size frequency distributions indicated that the population comprised small males, small immature females,
and large mature females, which was confirmed by dissections. No transitional individuals were found. Males maintained in
the laboratory molted 1–8 times, and many grew up to reach sizes observed in only a small fraction of males in the field.
No indication of sex change was recorded. Our results indicate that H. williamsi is a sexually dimorphic gonochoric species and emphasizes the importance of using several kinds of evidence (size measurements,
growth experiments, morphological dissections, and histological studies) to reveal the sexual system of Hippolyte species. Whether the observed size dimorphism between males and females in many species of Hippolyte is expression of contrasting sexual and natural selection, and whether divergent sexual fitness functions can contribute
to the evolution of hermaphroditism remains to be revealed in future studies. 相似文献
395.
A morphological and structural study of the larval shell from the abalone <Emphasis Type="Italic">Haliotis tuberculata</Emphasis> 总被引:1,自引:0,他引:1
E. Jardillier M. Rousseau A. Gendron-Badou F. Fröhlich D. C. Smith M. Martin M.-N. Helléouet S. Huchette D. Doumenc S. Auzoux-Bordenave 《Marine Biology》2008,154(4):735-744
The larval shell of the marine gastropod Haliotis tuberculata was investigated by polarised light microscopy, scanning electron microscopy, Raman microspectroscopy and infra-red spectroscopy.
Trochophore and veliger larval sections were used for histological examination of the growing shell and each larval stage
was related to the shell development and the appearance of calcified formations. We determined the stage of initial calcification
by specific staining combined with polarised light examination. The shell of 30-h-old pre-veliger larvae was found to be mineralized,
confirming that calcification occurred before larval torsion. Using both infra-red and Raman spectroscopy, we showed that
CaCO3 deposition occurred at the pre-veliger stage and that the mineral phase initially deposited was essentially composed of aragonite. 相似文献
396.
Simon Anthony Morley Koh Siang Tan Robert W. Day Stephanie M. Martin Hans-O. Pörtner Lloyd S. Peck 《Marine Biology》2009,156(10):1977-1984
The upper thermal limits for burrowing and survival were compared with micro-habitat temperature for anomalodesmatan clams:
Laternula elliptica (Antarctica, 67°S); Laternula recta, (temperate Australia, 38°S) and Laternula truncata (tropical Singapore, 1°N). Lethal limits (LT50) were higher than burrowing limits (BT50) in L. elliptica (7.5–9.0 and 2.2°C) and L. recta (winter, 32.8–36.8 and 31.1–32.8°C) but the same range for L. truncata (33.0–35.0 and 33.4–34.9°C). L. elliptica and L. truncata had a BT50 0.4 and 2.4–3.9°C, respectively, above their maximum experienced temperature. L. recta, which experience solar heating during midday low tides, had a BT50 0.7–2.4°C below and a range for LT50 that spanned their predicted environmental maximum (33.5°C). L. recta showed no seasonal difference in LT50 or BT50. Our single genus comparisons contrast with macrophysiological studies showing that temperate species cope better with elevated
temperatures.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
397.
The systematic conservation planning literature invariably assumes that the biodiversity features being preserved in sites do not change through time. We develop a conservation planning framework for ecosystems where disturbance events and succession drive vegetation dynamics. The framework incorporates three key attributes of disturbance theory: heterogeneity in disturbance rates, spatial correlation between disturbance events and different impacts of disturbance. In our conservation problem we wish to maximise the chance that we represent a certain number of successional types given a cap on the number of sites we can conserve. Correlation between disturbance events dramatically complicates the problem of choosing the optimal suite of sites. However, in our problem we discover that spatial correlation in disturbances affects the optimal reserve network very little. The reason is twofold: (i) through our probabilistic framework we focus on the long-term effectiveness of reserve networks and (ii) in the dynamics considered in our model the state of a site is not only affected by the most recent (correlated) disturbance event but also by the site's long-term stochastic history which blurs the impact of spatial correlation. If successional states are the conservation target rather than individual species then, conserving a site can only contribute to meeting one target. However, given that correlation of disturbance events may be ignored, we show that if the number of candidate reserves is sufficiently large the statistical dependence of different conservation targets may be ignored, too. We conclude that the computational complexity of reserve selection methods for dynamic ecosystems can be much simpler than they first appear. 相似文献
398.
地球系统工程与区域环境问题调控的原则 总被引:2,自引:2,他引:0
论述了地球系统科学和工程研究的发展历史、研究对象和方法,及其在解决全球性环境危机中的作用;阐述了提高共识、言行一致、保护全球公共资源、实现可持续性目标等地球系统工程的基本原则. 论述了区域性与地球系统环境问题间的关系,提出区域环境问题调控的4条基本原则:系统性调控、区际公平、多方合作、综合手段和共同约束. 指出应注重应用地球系统科学与工程的理论与方法解决区域环境与生态问题;应深入探讨地球系统及区域环境与生态压力在中国现阶段的特征,统筹全局与长远调控区域环境问题;应开展长期连续观测和信息共享,创新调控全球与区域环境与生态的技术、方法. 相似文献
399.
With the advancement of computational systems and the development of model integration concepts, complexity of environmental model systems increased. In contrast to that, theory and knowledge about > environmental systems as well as the capability for environmental systems analyses remained, to a large extent, unchanged. As a consequence, model conceptualization, data gathering, and validation, have faced new challenges that hardly can be tackled by modellers alone. In this discourse-like review, we argue that modelling with reliable simulations of human-environmental interactions necessitate linking modelling and simulation research much stronger to science fields such as landscape ecology, community ecology, eco-hydrology, etc. It thus becomes more and more important to identify the adequate degree of complexity in environmental models (which is not only a technical or methodological question), to ensure data availability, and to test model performance. Even equally important, providing problem specific answers to environmental problems using simulation tools requires addressing end-user and stakeholder requirements during early stages of problem development. In doing so, we avoid modelling and simulation as an end of its own. 相似文献
400.
Douglas G. Sprugel Katherine G. Rascher Rolf Gersonde Martin Dovčiak James A. Lutz Charles B. Halpern 《Ecological modelling》2009
Young forests can be manipulated in diverse ways to enhance their ecological values. We used stem maps from two dense, second-growth stands in western Washington and a spatially explicit light model (tRAYci) to simulate effects of five silvicultural manipulations on diameter distribution, species composition, spatial patterning, and light availability. Each treatment removed 30% of the basal area, but differed in how trees were selected for removal. Three primary treatments were thin from below (removing the smallest trees), random thin (removing trees randomly), and gap creation (removing all trees in circles ∼1 tree height in diameter). Two additional treatments combined elements of these approaches: random ecological thin (a mixture of thin from below and random thin) and structured ecological thin (a mixture of thin from below and gap creation). 相似文献