全文获取类型
收费全文 | 126篇 |
免费 | 1篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 6篇 |
环保管理 | 13篇 |
综合类 | 31篇 |
基础理论 | 29篇 |
污染及防治 | 35篇 |
评价与监测 | 2篇 |
社会与环境 | 8篇 |
出版年
2022年 | 2篇 |
2019年 | 1篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 14篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1979年 | 1篇 |
1962年 | 4篇 |
1961年 | 2篇 |
1959年 | 2篇 |
1955年 | 3篇 |
1954年 | 1篇 |
1922年 | 1篇 |
排序方式: 共有131条查询结果,搜索用时 31 毫秒
21.
Schröder FR Schulze C Matthies M 《Environmental science and pollution research international》2002,9(2):130-135
The GREAT-ER software was used to calculate linear alkylbenzene sulphonate [LAS] and boron concentrations in the Itter stream in North Rhine-Westfalia, Germany. The aim was to investigate the predictive strength of this newly developed tool and to compare its results to measured data. Substance-specific input data which were used in this scenario were partly generic (e.g. LAS and sodium perborate tetrahydrate consumption figures for Germany) and partly (site-)specific data (e.g. half-life time for LAS elimination). The comparison with the measured data reveals that the model predictions for LAS and boron are correct at least within a factor of two, only if generic German consumption data is applied. By using refined input data, the accuracy can be increased further. 相似文献
22.
23.
We consider contracting of a principal with an agent if multilateral externalities are present. The motivating example is that of an international climate agreement given private information about the willingness-to-pay (WTP) for emissions abatement. Due to multilateral externalities the principal uses her own emissions besides subsidies to incentivize the agent and to assure his participation. Optimal contracts equalize marginal abatement costs and, thus, can be implemented by a system of competitive permit trading. Moreover, optimal contracts can include a boundary part (i.e., the endogenous, type dependent participation constraint is binding), which is not a copy of the outside option of no contract. Compared to this outside option, a contract can increase emissions of the principal for types with a low WTP, and reduce her payoff for high types. Subsidies can be constant or even decreasing in emission reductions, and turn negative so that the agent reduces emissions and pays the principal. 相似文献
24.
Dirk Erpenbeck John N. A. Hooper Isabelle Bonnard Patricia Sutcliffe Mayuri Chandra Pierre Perio Carsten Wolff Bernard Banaigs Gert W?rheide Cécile Debitus Sylvain Petek 《Marine Biology》2012,159(5):1119-1127
Sponges of the family Dysideidae (Dictyoceratida) are renowned for their diversity of secondary metabolites, and its genus Lamellodysidea, particularly Lamellodysidea herbacea, is the most studied taxon biochemically. Despite its importance, the taxonomic status of L. herbacea—whether it is a distinct species or a species complex—has never been assessed. Recent biochemical profiling revealed anti-plasmodial activity of brominated compounds in Lamellodysidea of the Pacific. Here, we present a comparative chemotaxonomic and molecular analysis of selected Dysideidae from the Pacific and the Indian Ocean (New Caledonia, Great Barrier Reef, Fiji, Mayotte, Guam, Palau). We investigated the phylogenetic relationships between the populations and assessed their bioactive (PBDE) compounds in order to unravel the taxonomic status of this commercially important group of sponges and assessed patterns of dispersal and biochemical variation. The molecular phylogeny was based on the internal transcribed ribosomal spacer and compared against a PBDE phylogeny for several specimens. Molecular data revealed a diversity of Indo-Pacific L. herbacea populations, also reflected by different PBDE compound profiles. Molecular and biochemical data also revealed a Lamellodysidea species new to science. Several specimens misidentified as Lamellodysidea were detected based on their position on different clades in the molecular phylogeny and their production of different halogenated compounds (brominated vs. chlorinated). The direct comparison of molecular and biochemical data also provided evidence for the occurrence of a host switch event and support for the theory that abiotic factors, such as sedimentation, affect the chemical constituents produced in L. herbacea. 相似文献
25.
Duester L Prasse C Vogel JV Vink JP Schaumann GE 《Journal of environmental monitoring : JEM》2011,13(5):1204-1211
The pore water transport of antimony and titanium, applied as nanoparticles (NPs), was studied by spiking stable suspensions of two different nanomaterials on the surface of an undisturbed floodplain soil. For preparation of stable dispersions, two different strategies were followed. (i) Comparable to those used in industrial applications: titanium dioxide nanoparticles, with an average diameter of 99 nm, were prepared by high-energy ball milling in water, whereas for (ii) antimony trioxide (Sb(2)O(3); average diameter 121 nm) a dispersing agent (sodium salt of poly[(naphthaleneformaldehyde)sulfonate] (pNFS) in water) was used. The upper 17 cm of a floodplain soil (river Rhine, Germany) was sampled using the minimally invasive sediment or fauna incubation experiment (SOFIE? two compartment cell; 3 l volume each), which preserved the pore system of the soil. The cells were equipped with 450 and 100 nm filter probes at different depths providing a non-invasive sampling of the pore water. The pore water was sampled at different times (T = 0, 24, 48, 96 and 196 h) and analysed by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Sb and Ti were transported via the pore water of the floodplain soil to a depth of 14 cm, corresponding to the maximum cell depth. The highest Sb concentration in the pore water was detected after 24 h at a depth of 5.5-8 cm. Although the spiked concentration was higher for Ti than for Sb, the total Ti concentration in the pore water of the spiked cell was lower. This indicates a stronger agglomeration of TiO(2) NPs or a more intensive interaction of Ti with the solid matrix and a faster transport of Sb towards deeper soil layers. The results show that metal(loid)s from metal oxide NPs are transported in the soil pore water and, hence, have the potential to act as the source of contamination of deeper soil layers after soil surface contamination. 相似文献
26.
Rapid tissue reduction and recovery in the sponge <Emphasis Type="Italic">Aplysinella</Emphasis> sp.
We observed a pronounced, yet reversible tissue reduction in the tropical sponge Aplysinella sp. under non-experimental conditions in its natural habitat, after transfer into seawater tanks, as well as after transplantation
from deep to shallow water in the field. Tissue reduction resulted in the formation of small “reduction bodies” tightly attached
to the sponge skeleton. Although volume loss and gain were substantial, both tissue reduction and regeneration were often
remarkably rapid, occurring within few hours. Microscopic analysis of the reduction bodies revealed morphological similarities
to previously described sponge primmorphs, with densely packed archaeocytes and spherulous cells enclosed by a thin layer
of epithelial-like cells. Denaturing gradient gel electrophoresis (DGGE) revealed pronounced changes in the sponge-associated
microbial community upon tissue reduction during laboratory and field experiments and following changes in ambient conditions
after transplantation in the field. Generally, the microbial community associated with this sponge proved less stable, less
abundant, and less diverse than those of other, previously investigated Verongid sponges. However, one single phylotype was
consistently present in DGGE profiles of Aplysinella sp. This phylotype clustered with γ-proteobacterial sequences found previously in other sponge species of different taxonomic
affiliations and geographic provenances, as well as in sponge larvae. No apparent changes in the total secondary metabolite
content (per dry weight) occurred in Aplysinella sp. upon tissue reduction; however, comparative analysis of intact and reduced tissue suggested changes in the concentrations
of two minor compounds. Besides being ecologically interesting, the tissue reduction phenomenon in Aplysinella sp. provides an experimentally manipulable system for studies on sponge/microbe symbioses. Moreover, it may prove useful
as a model system to investigate molecular mechanisms of basic Metazoan traits in vivo, complementing the in vitro sponge
primmorph system currently used in this context. 相似文献
27.
Hawkins BA Diniz-Filho JA Bini LM Araújo MB Field R Hortal J Kerr JT Rahbek C Rodríguez MA Sanders NJ 《Ecology》2007,88(8):1898-1902
28.
The Science of Nature - 相似文献
29.
Territoriality is of great significance for many species and a characteristic of most group-living animals. Territoriality is thought to lead to increased reproductive success by defending a particular area containing critical resources. I describe several factors that influence territorial aggression in free-ranging striped mice (Rhabdomys pumilio), a group-living solitary forager. I induced territorial aggression by attracting mice of different groups using bait either at territory boundaries or in front of nests. Striped mice are territorial and make decisions about whether or not to attack a mouse from another group based upon several factors: (1) the sex of the opponent: males are much more likely to attack strange males than strange females, whereas no sex specific aggression was observed in females; (2) the body size of the opponent: striped mice are much more likely to attack a strange mouse that is lighter than themselves; and (3) the location of encounters: striped mice are much more likely to attack strangers, even those significantly heavier than themselves, in front of the nest than at territory boundaries. These variations in territorial responses between different types of individuals may be due to the different ultimate consequences of territorial aggression for different animals.Communicated by S. Alberts 相似文献
30.
Gerd Ulrich Balcke Heidrun Paschke Carsten Vogt Mario Schirmer 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2011-2018
Chlorobenzene-contaminated groundwater was used to assess pulsed gas sparging as a minimum effort aeration strategy to enhance intrinsic natural attenuation. In contrast to existing biosparging operations, oxygen was supplied at minimum rate by reducing the gas injection frequency to 0.33 day?1. Field tests in a model aquifer were conducted in a 12 m long reactor, filled with indigenous aquifer material and continuously recharged with polluted groundwater over 3 years. The closed arrangement allowed yield balances, cost accounting as well as the investigation of spatial distributions of parameters which are sensitive to the biodegradation process. Depending on the injection frequency and on the gas chosen for injection (pure oxygen or air) oxygen-deficient conditions prevailed in the aquifer. Despite the limiting availability of dissolved oxygen in the groundwater, chlorobenzene degradation under oxygen-deficient conditions proved to be more effective than under conditions with dissolved oxygen being available in high concentrations. 相似文献