全文获取类型
收费全文 | 662篇 |
免费 | 10篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 37篇 |
废物处理 | 31篇 |
环保管理 | 103篇 |
综合类 | 97篇 |
基础理论 | 147篇 |
污染及防治 | 180篇 |
评价与监测 | 49篇 |
社会与环境 | 27篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 5篇 |
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 21篇 |
2016年 | 15篇 |
2015年 | 23篇 |
2014年 | 25篇 |
2013年 | 50篇 |
2012年 | 25篇 |
2011年 | 40篇 |
2010年 | 28篇 |
2009年 | 31篇 |
2008年 | 35篇 |
2007年 | 43篇 |
2006年 | 40篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 24篇 |
2002年 | 24篇 |
2001年 | 10篇 |
2000年 | 20篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 14篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1961年 | 2篇 |
1959年 | 2篇 |
1958年 | 1篇 |
1957年 | 2篇 |
1953年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有677条查询结果,搜索用时 93 毫秒
581.
Pawlik-Skowrońska B 《Environmental pollution (Barking, Essex : 1987)》2002,119(1):119-127
Comparing Pb toxicity to the green alga Stichococcus bacillaris and production of Pb-induced thiol peptides in 24-h exposed cells made it possible to show the level of these peptides to reflect Pb availability to algal cells. LC-ESI/MS analysis of these peptides confirmed that they are phytochelatins PC2-PC4 and their des-Gly derivatives. Studies were carried out at environmentally relevant pH values (5-8.5) and various concentrations of hardness cations (Ca, Mg) and orthophosphate: (0-0.1 mM), chloride (0-100 mM), citrate (0-1 mM), and humic acids (0-10 mg/l). It has been stated, on the basis of the level of Pb-induced thiol peptides, that Pb availability to algae changed significantly within the range of the pH values studied, and was limited in the presence of calcium and of some complexing ligands like orthophosphate, chloride and citrate; it did not decrease in the presence of magnesium or humic acid. 相似文献
582.
Blood zinc level, hematological parameters and blood cell morphology were evaluated in common carp immediately after 3 h exposure to 20 mg dm(-3) of zinc (Zn0), and in 24, 48 and 96 hours after the end of it (Zn24, Zn48, Zn96). Blood zinc level in the non-exposed fish was 8 mg dm(-3), reached a maximum of 20 mg dm(-3) in Zn48, while it dropped to 9 mg dm(-3) in Zn96. Zinc caused a stress reaction in fish indicated by an increase in hematocrit value in Zn0, and elevated plasma glucose level and trombocytosis which persisted until the end of the experiment. Zinc-exposed fish showed an increased frequency of abnormal erythrocytes, and a compensatory release of immature erythrocytes to the blood stream. In zinc-treated fish, leukocyte count initially increased and subsequently decreased significantly below the control level due to a drop in lymphocyte number. Lymphocyte viability was reduced, and abnormal lymphocytes appeared. A decreased count of juvenile neutrophiles, and reduced phagocyte activity also occurred. The results indicate possible zinc-induced disturbances in both specific and non-specific immune mechanisms. 相似文献
583.
A one-dimensional flow and transport model was developed to describe the movement of two fluid phases, gas and water, within a porous medium and the transport of 226Ra and 222Rn within and between these two phases. Included in this model is the vegetative uptake of water and aqueous 226Ra and 222Rn that can be extracted from the soil via the transpiration stream. The mathematical model is formulated through a set of phase balance equations and a set of species balance equations. Mass exchange, sink terms and the dependence of physical properties upon phase composition couple the two sets of equations. Numerical solution of each set, with iteration between the sets, is carried out leading to a set-iterative compositional model. The Petrov-Galerkin finite element approach is used to allow for upstream weighting if required for a given simulation. Mass lumping improves solution convergence and stability behavior. The resulting numerical model was applied to four problems and was found to produce accurate, mass conservative solutions when compared to published experimental and numerical results and theoretical column experiments. Preliminary results suggest that the model can be used as an investigative tool to determine the feasibility of phytoremediating radium and radon-contaminated soil. 相似文献
584.
A 40+ year record of Cd,Hg, Pb,and U deposition in sediments of Patroon Reservoir,Albany County,NY, USA 总被引:13,自引:0,他引:13
Sediments of the Patroon Creek watershed (33 km(2)) are known to contain significant concentrations of heavy metals derived from two industrial sites within the watershed. Mercury Refining, Inc (Mereco) has stored and recycled Hg from 1955 to the present day, and National Lead Industries (NLI) manufactured aircraft components containing Cd, Pb, and U from 1958 to 1984. Here we present the first record of heavy metal deposition as preserved in a 3-m long sediment core collected in 1999 from Patroon Reservoir, a small water body (1.3 ha) downstream of the industrial sites. Bulk sediment samples were collected from the core at 0.05-m intervals and analyzed for total Cd, Pb, and U by ICP-MS and total Hg by CVAAS. Total Hg increases from less than 1 mg kg(-1) (dw) below 1.68 m, to a maximum of 6.2 mg kg(-1) at 0.80 m, and then declines to the sediment-water interface. Total Cd, Pb, and U concentrations increase abruptly above 1.68 m to maximum values of 25, 320, and 3600 mg kg(-1) (dw), respectively, and then decline gradually upwards. By correlating metal profiles with industrial history, we conclude that the 1.68 m horizon was deposited no earlier than 1958, the beginning of aircraft component manufacturing at NLI. The average, apparent sedimentation rate within the reservoir has a minimum value of approximately 0.04 m year(-1) for the 41-year period from 1958 to 1999. In the interval 0--1.68 m, average concentrations of Cd, Hg, Pb, and U are 1.69, 1.50, 461, and 13 mg kg(-1), respectively. These levels are comparable with other lake, reservoir and stream sediments that have been moderately to severely impacted by industrial pollution and are above levels expected to be detrimental to aquatic organisms. 相似文献
585.
This paper reports the bioaccumulation of three PCBs (2,4′-dichlorobiphenyl, 2,4,6,2′-tetrachlorobiphenyl and 2,4,6,2′,4′-pentachlorobiphenyl) by the green alga under various conditions. A probable pattern of the bioconcentration mechanism is suggested. No metabolites were extracted from algae or water 6 days after incubation with PCBs. 相似文献
586.
Oviposition behavior of insects has associated fitness costs related to the probability that females survive to oviposit.
During summer 2003, we observed the oviposition behavior and compared the mortality rates of females of 17 mayfly species
in one western Colorado watershed. We dissected adult females collected on terrestrial sticky traps, in drift nets submerged
in streams, and in stomachs of brook trout to determine whether the mayflies had oviposited before capture, drowning, or consumption.
Females oviposited by either splashing on the water surface releasing all their eggs (splashers), dropping their eggs from
the air (bombers), dipping their abdomens multiple times releasing a few eggs at a time (dippers), landing on rocks and ovipositing
on the undersides (landers), or floating downstream while releasing their eggs (floaters). Almost 100% of lander and 50% of
dipper females had not oviposited when captured on sticky traps, increasing their vulnerability to preoviposition mortality
by aerial predators compared to mayflies with other behaviors. In contrast, most females had laid their eggs before drowning
or being eaten by a fish (50–90%). However, groups with oviposition behaviors most exposed to the water surface (floaters,
then splashers, dippers, and landers) were more vulnerable to drowning before completing oviposition. In addition, splashers
and floaters were most vulnerable to predation by brook trout before ovipositing. These data suggest that fitness costs associated
with preoviposition mortality may be considerable depending on mayfly oviposition behavior. Furthermore, previously demonstrated
benefits of low predation rates on eggs of lander species may be offset in part by costs to female survival.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
587.
The Environmental Auditing Roundtable (EAR) is the single largest professional organization in the world, representing over 900 members. Built on a tradition of promoting environmental auditing through openly sharing experiences in the field of safety, health, and environmental auditing, the organization in recent years has significantly expanded its influence on auditing practices both nationally and internationally by monitoring audit activities and participating in the development of audit policy, regulation, standardization, and the certification of environmental auditors. This article describes the origin and evolution of the organization from meeting the needs of the membership to addressing the needs of external national and international stakeholders. 相似文献
588.
Many organizations in environmental fields stand to benefit from the use of a geographic information system (GIS). Selecting
a GIS to implement within an organization can be a difficult task that is often required of people with little experience
using a GIS. A framework for evaluating competing GIS considers cost, functionality, ease of use, future stability, development
potential, support availability, and maintenance costs. Initial cost involves more than the actual purchase price of hardware
and software; it includes the cost of building the data base and training users within the organization. Functionality refers
to the depth and breadth of capabilities of a GIS. Issues involved in evaluating functionality include the appropriateness
of raster vs vector processing and the ability to add your own software. Ease of use is important, but there is generally
a trade-off with functionality. The degree of centralization of use of the GIS within the organization affects requirements
for ease of use. GIS are rapidly evolving, and as a result it is important to select a system with high potential for future
development. With the proliferation of companies offering GIS it is important to select one that is likely to survive and
prosper. Similarly, the ability to find support in the forms of technical help, advice, and possibly even skilled employees
can be significant. 相似文献
589.
590.