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901.
Fangli Su Tieliang Wang Haozhen Zhang Zhi Song Xue Feng Kan Zhang 《Environmental monitoring and assessment》2018,190(6):365
The aims of the present investigation were to reveal the distribution and enrichment characteristics of copper in soil and Phragmites australis of Liao River estuary wetland. The concentrations of copper in root, stem, leaf, and ear of Phragmites australis as well as in soil were determined to study the absorption capacity of copper by wild Phragmites australis of Liao River estuary wetland. The study was carried out at test pool of the Shenyang Agricultural University, and the experimental materials (soil, irrigating water and Phragmites australis) were derived from Liao River estuary wetland. The concentrations of copper in soil and Phragmites australis were 16.4441 to 49.0209 mg/kg and 0.8621 to 89.5524 mg/kg, respectively. The results indicated that the enrichment coefficients of copper in different tissues of Phragmites australis changed with the growth of Phragmites australis. The results revealed that the enrichment coefficients of copper in the whole Phragmites australis were greater than 1 at each growing stage of the Phragmites australis. The results also showed that the transfer coefficients of Phragmites australis to copper changed with the growth of Phragmites australis. The results revealed that the Phragmites australis had a good removal effect on copper from soil and had some characteristics of copper hyperaccumulator. 相似文献
902.
Divia P. Sreenivasan A. Sujith C. Rajesh 《Journal of Polymers and the Environment》2018,26(7):2720-2729
Biocomposites of acrylonitrile butadiene rubber (NBR) reinforced with chicken feather fibre (CF) were prepared using dicumyl peroxide (DCP) as vulcanizing agent. Composites with three series of chicken feather fibres were studied i.e., raw (RCF), sterilized (SCF) and alkali treated (ACF). The cure characteristics of composites were studied. The mechanical properties of NBR were found to be improved by the incorporation of chicken feather fibre in all forms. Surface modification of the fibre was done by alkaline treatment to improve the interfacial adhesion and it characterised by FTIR. Better properties are shown by the composites with ACF. The swelling behaviour of the composites in N,N-dimethylformamide, acetonitrile, dimethyl sulfoxide and water were analyzed for the swelling coefficient values. The biodegradable characteristics of CF reinforced NBR composites were studied by soil burial test which indicated that it is an eco-friendly and acceptable material. Scanning electron microscopy studies support the results of mechanical properties. The outcome obtained from this study is believed to assist the development of environmentally–friendly composites especially for specific product applications like oil seals, hoses and automobile bushes etc. 相似文献
903.
The present investigation dealt with the flow behavior and processability of polylactic acid/polystyrene (PLA/PS) polymer blends using a capillary rheometer. For this purpose, PLA/PS blends with different ratios of the concentrations were prepared using a single screw extruder. The shear viscosity, shear stress, shear rate, power-law index, viscous activation energy at a constant shear stress, and elongational stress were determined. PLA/PS blends exhibited a typical shear-thinning behavior over the entire range of shear rates tested, and the viscosity values of the blends would tend to decrease with increasing amount of PLA. In addition, the polymer blend of 70 % PLA and 30 % PS was found to be relatively less sensitive to the processing temperature, implying that the extrusion process was more desirable for fabrication of PLA/PS polymer blend than the injection process. 相似文献
904.
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
905.
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
906.
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
907.
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
908.
Sara Romani Seyed Reza Mohebbi Seyed Masoud Hosseini Pedram Azimzadeh Mohsen Vahedi Faramarz Derakhshan Mohammad Reza Zali 《Food and environmental virology》2012,4(1):1-5
Noroviruses are one of important agents that cause acute viral gastroenteritis worldwide. These viruses are belonging to Caliciviridae
family and are genetically diverse. To date, there is no valuable data about prevalence of norovirus infection and the dominant
genogroup/genotype among Iranian population. The objective of this study was to determine the frequency of norovirus infection
in Iranian patients with gastroenteritis referred to three hospitals of Tehran and to specify the dominant genogroup/genotype
of this virus among our study population. A total of 293 patients with acute gastroenteritis were included in the study. Detection
of norovirus was performed using RT-PCR method and confirmed by direct sequencing with specific designed primers for capsid
region of norovirus genome. Phylogenetic analysis was performed using the neighbor-joining method. Norovirus strains identified
in our study were subsequently categorized according to previously defined genogroup/genotypes. Of these, norovirus GII was
dominant genogroup. Sixty-five percent (17 of 26) of positive samples were determined as GII and 35% (9 of 26) were determined
as GI, respectively, in 2008–2009. And among 8 sequenced strains of genogroup II the most frequent genotype was GII.3. The
results of this study indicated that norovirus must be considered as one of the infectious causes of acute gastroenteritis
among Iranian population. We also found that GII.3 is more prevalent in our study population. To the best of our knowledge
there is limited data about the role of noroviruses in children and adults’ acute gastroenteritis among Iranian patients and
this prevalence and genotyping report of norovirus infection could be remarkable for further studies. 相似文献
909.
Monavari SM Omrani GA Karbassi A Raof FF 《Environmental monitoring and assessment》2012,184(4):1841-1846
Environment problems associated with the generation of waste are part of societal changes where households play an important
role. These societal changes influence the size, structure and characteristic of given households. For the effective planning
of solid-waste handling infrastructure, it is essential to know the quantity of waste generation and its composition. This
paper presents the findings of a study carried out in an urban municipal area in Iran to determine the household solid-waste
generation rate and waste composition based on field surveys and to determine the related socioeconomic parameters. The dependent
variables were waste generation and composition, and independent variables were family size, family employment, age, number
of room and education. Over 400 sample households were selected for the study using a stratified random sampling methodology
and from five different socioeconomic groups. Waste collected from all groups of households were segregated and weighted.
Waste generation rate was 5.4 kg/household/day. Household solid waste comprised of ten categories of wastes and with the largest
component (76.9%). The generation and composition of household solid waste were correlated with family size, education level
and households income. This paper adequately suggests new insights concerning the role of socioeconomic parameters in affecting
the generation of household waste. 相似文献
910.
Mehmet Cetin Ilknur Zeren Hakan Sevik Cansel Cakir Huseyin Akpinar 《Environmental monitoring and assessment》2018,190(3):167
The surface site of Yesilyuva Nature Park encompasses natural, social, economic, and cultural characteristics and has become a marker of the region’s natural and cultural heritage. To support the preservation of this site, promotional activities should be planned. In this study, because of tourism and related opinions of residents and visitors alike in terms of their natural determination, an important cultural and historical feature is aimed at evaluating the tourism potential of Yesilyuva Nature Park. This framework is designed to establish prospective tourism sustainability. As a result, Yesilyuva Nature Park’s natural and cultural properties have been determined to be suitable for sustainable tourism activities using geographic information systems (GIS). This protection in the field, which balances sustainability and landscape design, will provide for the development of tourism activities. In the Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis and survey, residents and visitors reported that the most important feature of the Yesilyuva Nature Park was its natural beauty. Visitors often come to observe traditional and natural life and to engage in tourism activities. All the data, which includes maps derived from GIS, represents landscape planning for sustainable tourism areas in Yesilyuva Nature Park. 相似文献