全文获取类型
收费全文 | 9670篇 |
免费 | 0篇 |
专业分类
废物处理 | 768篇 |
环保管理 | 1211篇 |
综合类 | 936篇 |
基础理论 | 3113篇 |
污染及防治 | 1738篇 |
评价与监测 | 1007篇 |
社会与环境 | 896篇 |
灾害及防治 | 1篇 |
出版年
2021年 | 1篇 |
2019年 | 3篇 |
2018年 | 1475篇 |
2017年 | 1371篇 |
2016年 | 1196篇 |
2015年 | 124篇 |
2014年 | 17篇 |
2013年 | 7篇 |
2012年 | 461篇 |
2011年 | 1339篇 |
2010年 | 692篇 |
2009年 | 599篇 |
2008年 | 883篇 |
2007年 | 1226篇 |
2006年 | 6篇 |
2005年 | 20篇 |
2004年 | 32篇 |
2003年 | 62篇 |
2002年 | 98篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 3篇 |
1998年 | 10篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1935年 | 2篇 |
排序方式: 共有9670条查询结果,搜索用时 0 毫秒
991.
Ignacio J. Moncho-Esteve Frederik Folke Manuel García-Villalba Guillermo Palau-Salvador 《Environmental Fluid Mechanics》2017,17(4):695-714
This paper presents large eddy simulation of turbulent flow in a meandering open channel with smooth wall and rectangular cross-section. The Reynolds number based on the channel height is 40,000 and the aspect ratio of the cross-section is 4.48. The depth-averaged mean stream-wise velocity agree well to experimental measurements. In this specific case, two interacting cells are formed that swap from one bend to the other. Transport and mixing of a pollutant is analysed using three different positions of release, e.g. on the inner bank, on the outer bank and on the centre of the cross section. The obtained depth-average mean concentration profiles are reasonably consistent with available experimental data. The role of the secondary motions in the mixing processes is the main focus of the discussion. It is found that the mixing when the scalar is released on the centre of the cross-section is stronger and faster than the mixing of the scalar released on the sides. When the position of release is close to a bank side, the mixing is weaker and a clear concentration of scalar close to the corresponding side-wall can be observed in both cases. 相似文献
992.
We present a new system for microscopic multicolour variable chlorophyll fluorescence imaging of aquatic phototrophs. The
system is compact and portable and enables microscopic imaging of photosynthetic performance of individual cells and chloroplasts
using different combinations of blue, green, red or white light. Automated sequential exposure of microscopic samples to the
three excitation colours enables subsequent deconvolution of the resulting fluorescence signals and colour marking of cells
with different photopigmentation, i.e., cyanobacteria, green algae, red algae and diatoms. The photosynthetic activity in
complex mixtures of phototrophs and natural samples can thus be assigned to different types of phototrophs, which can be quantified
simultaneously. Here, we describe the composition and performance of the new imaging system and present applications with
both natural phytoplankton and microalgal culture samples. 相似文献
993.
Distribution and availability of potentially toxic metals in soil in central area of Belgrade,Serbia 总被引:1,自引:0,他引:1
Rabia Ahmed Ghariani Ivan Gržetić Mališa Antić Snežana Nikolić Mandić 《Environmental Chemistry Letters》2010,8(3):261-269
Belgrade, capital city of Serbia, has over 1,600,000 inhabitants and over 400,000 vehicles trafficking every day on its streets.
The investigation of soil pollution was performed by sequential extraction analysis to investigate the availability of potentially
toxic metals (Zn, Cd, Pb, Co, Ni, Cu, Cr and Mn) under different oxidation and pH conditions. All investigated metals were
mainly extracted from soils with neutral or acidic extractants. Serious pollution was observed along roads and streets with
high traffic frequency, but Pb and Ni pollution was the highest since their concentrations exceed both soil Serbian standard
and Canadian guidance values and is characteristic for all investigated sites. Cd, Cu, Cr and Zn concentrations are moderately
high since they are between Canadian guideline and Serbian standard. 相似文献
994.
Ottesen RT Alexander J Langedal M Haugland T Høygaard E 《Environmental geochemistry and health》2008,30(6):623-637
Systematic geochemical mapping based on sampling and analysis of surface soils (0–2 cm) has been carried out in several Norwegian
cities. The soils in the oldest parts of the cities are contaminated with metals (especially Pb) and polycyclic aromatic hydrocarbons
(PAH). Due to the fact that children are often in contact with surface soil, it was realized that special focus had to be
directed towards soils in day-care centers and playgrounds. The first mapping and remedy program was initiated in Trondheim
in 1996. Here, the importance of copper–chromium–arsenic (CCA)-pressure-impregnated wood in playing equipment as a pollution
source for soils was documented, and a process was started with the aim to ban this product. Soils from day-care centers in
the inner city of Bergen were polluted to a degree that required remediation in 45% out of 87 centers, mainly due to high
concentrations of Pb and benzo(a)pyrene. In Oslo, 38% of 700 day-care centers needed remediation due to soil pollution by
Pb, BaP, Cd, Hg, Ni and PCB. Removal of CCA-impregnated wood was necessary in more than half of the day-care centers The Norwegian
parliament has decided to investigate all outdoor playing areas in day-care centers, playgrounds and schoolyards in Norway,
starting in 2007 with day-care centers in the ten largest cities and five most important industrial areas. The Norwegian Institute
of Public Health has developed quality criteria for soils in day-care centers and playgrounds for As, Cd, Cr6+, Hg, Ni, Pb, zinc, PAHsum16, benzo(a)pyrene, and PCBsum7. The Geological Survey of Norway has developed guidance for mapping of soil pollution (sampling, chemical analysis and reporting)
in day-care centers. Especially the sampling strategy has been developed in the period 1996–2007, and the preferred sampling
strategy is to collect at least 10 samples of surface soil (0–2 cm) from (1) “original soil” on the site, (2) artificial man-made
“hills”, and (3) soils used for growing vegetables. A total number of 2,000 day-care-centres are to be investigated, and necessary
remediation should be completed before the end of 2010. 相似文献
995.
David A. Feary 《Marine Biology》2007,153(2):153-161
Ecological theory predicts that habitat generalists are less prone to decline or extinction in response to habitat disturbance
than habitat specialists. One mechanism that may afford habitat generalists greater persistence is their ability to successfully
emigrate from degrading environments. This study compared the response of habitat specialist and generalist reef fish species
to live coral disturbance. In replicate coral colonies, live coral was experimentally degraded (low, medium and high coral
loss). Species continued residence within the colonies was then surveyed over time. In addition, the ability of habitat generalist
and specialist species to migrate between degraded (100% loss) and live coral colonies was compared. Habitat specialists exhibited
a higher propensity to remain in colonies with low levels of coral loss. However, there was no significant difference between
specialist and generalist species in continued residence in habitats with either medium or high levels of coral loss; both
functional groups showed low levels of residence. In terms of migration success, generalists moved further than specialists
and showed higher levels of successful migration over the majority of distances examined. The influence of habitat specialization
on the behavioral response to coral loss may be a useful predictor of changes to coral reef fish communities in response to
coral disturbance. 相似文献
996.
Frédéric Mineur Mark P. Johnson Christine A. Maggs Herre Stegenga 《Marine Biology》2007,151(4):1299-1307
Hull fouling is thought to have been the vector of introduction for many algal species. We studied ships arriving at a Mediterranean
harbour to clarify the present role of commercial cargo shipping in algal introductions. A total of 31 macroalgal taxa were
identified from 22 sampled hulls. The majority of records (58%) were of species with a known cosmopolitan geographical distribution.
Due to a prevalence of cosmopolitan species and a high turnover of fouling communities, species composition of assemblages
did not appear to be influenced by the area of origin, length of ship or age of coating. In the light of the present results,
hull fouling on standard trading commercial vessels does not seem to pose a significant risk for new macroalgal species introductions.
However, a high proportion of non-cosmopolitan species found on a ship with non-toxic coating may modify this assessment,
especially in the light of the increasing use of such coatings and the potential future changes in shipping routes. 相似文献
997.
The habitat experienced during early life-history stages can determine the number and quality of individuals that recruit
to adult populations. In a field experiment, biogenic habitat complexity was manipulated (presence or absence of foliose macroalgae)
at two depths (2–3 m and 5–6 m) and the habitat-dependent effects on recruitment of the black foot abalone (Haliotis iris) were examined at three field sites along the south coast of Wellington, New Zealand (41°20′S, 174°47′E), between July and
November 2005. Recruit density (<5 weeks post-settlement) was measured on cobbles covered with crustose coralline algae. Habitats
of low complexity (barrens treatments) had consistently greater densities of recruits than habitats of high complexity (algae
treatments). However, recruits in algae habitats were larger, and for deep habitats, there was greater survival in algae habitats
compared with barrens habitats. While depth had no significant effect on early recruit (<2 weeks post-settlement) density,
late recruit (<5 weeks post-settlement) density was greater in shallow habitats, and so it seems recruit survival was greater
in shallow habitats. In this experiment, algal habitat complexity had strong effects on early recruit abundance, but habitat-dependent
variations in recruit growth and survival may modify initial patterns of abundance and determine recruitment to adult abalone
populations. 相似文献
998.
Chung Duc Tran Stefan Petrus Salhofer 《Journal of Material Cycles and Waste Management》2018,20(1):110-126
E-waste management in Vietnam poses real challenges such as the lack of specific e-waste legislation, the strong involvement of “craft villages” and the missing of monitoring data. Many issues (e.g., pollution level, generated waste, health of workers and resident living at recycling sites) lead to the limited access to these craft villages. Thus, there is no comprehensive picture on e-waste management in Vietnam available today. This research focuses on the current situation of e-waste management. Sources of e-waste, collection and treatment in Vietnam are investigated by utilizing most available sources of information (published journals, unpublished works from projects and reports from institutes, ministry) together with the interviewed data from experts, collectors, workers and especially, biggest traders in the field. Based on this information, the processes applied in Vietnam, both in the formal and informal sector, have been analyzed systematically in terms of inputs, outputs, potential emissions and related risks for workers. From these aspects, a comparison in terms of legal frameworks, collection and treatment at both formal and informal sector between Vietnam and other countries in Asian region was undertaken. Thus, major challenges of e-waste management and relatively comprehensive image of e-waste management and treatment in Vietnam have been identified. 相似文献
999.
Burçak Ebin Martina Petranikova Christian Ekberg 《Journal of Material Cycles and Waste Management》2018,20(4):2018-2027
Nickel–metal hydride (NiMH) batteries contain high amount of industrial metals, especially iron, nickel, cobalt and rare earth elements. Although the battery waste is a considerable secondary source for metal and chemical industries, a recycling process requires a suitable pretreatment method before proceeding with recovery step to reclaim all valuable elements. In this study, AA- and AAA-type spent NiMH batteries were ground and then sieved for size measurement and classification. Chemical composition of the ground battery black mass and sorted six different size fractions were determined by an analytical technique. Crystal structures of the samples were analyzed by X-ray diffraction. Results show that after mechanical treatment, almost 87 wt% of the spent NiMH batteries are suitable for further recycling steps. Size classification by sieving enriched the iron content of the samples in the coarse fraction which is bigger than 0.25 mm. On the other hand, the amounts of nickel and rare earth elements increased by decreasing sample size, and concentrated in the finer fractions. Anode and cathode active materials that are hydrogen storage alloy and nickel hydroxide were mainly collected in finer size fraction of the battery black mass. 相似文献
1000.
An Interval-Parameter Waste-Load-Allocation Model for River Water Quality Management Under Uncertainty 总被引:1,自引:0,他引:1
A simulation-based interval quadratic waste load allocation (IQWLA) model was developed for supporting river water quality
management. A multi-segment simulation model was developed to generate water-quality transformation matrices and vectors under
steady-state river flow conditions. The established matrices and vectors were then used to establish the water-quality constraints
that were included in a water quality management model. Uncertainties associated with water quality parameters, cost functions,
and environmental guidelines were described as intervals. The cost functions of wastewater treatment units were expressed
in quadratic forms. A water-quality planning problem in the Changsha section of Xiangjiang River in China was used as a study
case to demonstrate applicability of the proposed method. The study results demonstrated that IQWLA model could effectively
communicate the interval-format uncertainties into optimization process, and generate inexact solutions that contain a spectrum
of potential wastewater treatment options. Decision alternatives can be generated by adjusting different combinations of the
decision variables within their solution intervals. The results are valuable for supporting local decision makers in generating
cost-effective water quality management strategies. 相似文献