全文获取类型
收费全文 | 10662篇 |
免费 | 59篇 |
国内免费 | 350篇 |
专业分类
安全科学 | 55篇 |
废物处理 | 840篇 |
环保管理 | 1282篇 |
综合类 | 1534篇 |
基础理论 | 3292篇 |
污染及防治 | 2063篇 |
评价与监测 | 1044篇 |
社会与环境 | 922篇 |
灾害及防治 | 39篇 |
出版年
2024年 | 2篇 |
2023年 | 12篇 |
2022年 | 47篇 |
2021年 | 35篇 |
2020年 | 43篇 |
2019年 | 28篇 |
2018年 | 1503篇 |
2017年 | 1418篇 |
2016年 | 1233篇 |
2015年 | 191篇 |
2014年 | 86篇 |
2013年 | 90篇 |
2012年 | 528篇 |
2011年 | 1422篇 |
2010年 | 752篇 |
2009年 | 645篇 |
2008年 | 947篇 |
2007年 | 1280篇 |
2006年 | 65篇 |
2005年 | 66篇 |
2004年 | 59篇 |
2003年 | 101篇 |
2002年 | 138篇 |
2001年 | 57篇 |
2000年 | 46篇 |
1999年 | 45篇 |
1998年 | 46篇 |
1997年 | 24篇 |
1996年 | 25篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 20篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1973年 | 1篇 |
1935年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
591.
Rai PK 《Environmental monitoring and assessment》2012,184(1):113-131
The present article provides a multifaceted critical research review on environmental issues intimately related with the socio-economy
of North East India (NE), a part of Indo-Burma hotspot. Further, the article addresses the issue of sustainable development
of NE India through diverse ecological practices inextricably linked with traditional ecological knowledge (TEK). The biodiversity
of NE India comprises endemic floral diversity, particularly medicinal plants of importance to pharmaceutical industry, and
unique faunal diversity. Nevertheless, it is very unfortunate that this great land of biodiversity is least explored taxonomically
as well as biotechnologically, probably due to geographical and political constraints. Different anthropogenic and socio-economic
factors have perturbed the pristine ecology of this region, leading to environmental degradation. Also, the practice of unregulated
shifting cultivation (jhooming), bamboo flowering, biological invasions and anthropogenic perturbations to biodiversity exacerbate the gloomy situation.
Instead of a plethora of policies, the TEK of NE people may be integrated with modern scientific knowledge in order to conserve
the environment which is the strong pillar for socio-economic sector here. The aforesaid approach can be practiced in NE India
through the broad implementation and extension of agroforestry practices. Further, case studies on Apatanis, ethnomedicinal plants use by indigenous tribal groups and sacred forests are particularly relevant in the context of conservation
of environmental health in totality while addressing the socioeconomic impact as well. In context with the prevailing scenarios
in this region, we developed an eco-sustainable model for natural resource management through agroforestry practices in order
to uplift the social as well as environmental framework. 相似文献
592.
The presence of natural estrogen hormones as trace concentrations in the environment has been reported by many researchers
and is of growing concern due to its possible adverse effects on the ecosystem. In this study, municipal biosolids, poultry
manure (PM) and cow manure (CM), and spent mushroom compost (SMC) were analyzed for the presence of seven estrogen hormones.
17α-estradiol, 17β-estradiol, 17α-dihydroequilin, and estrone were detected in the sampled biosolids and manures at concentrations
ranging from 6 to 462 ng/g of dry solids. 17α-estradiol, 17β-estradiol, and estrone were also detected in SMC at concentrations
ranging from 4 to 28 ng/g of dry solids. Desorption experiments were simulated in the laboratory using deionized water (milli-Q),
and the aqueous phase was examined for the presence of estrogen hormones to determine their desorption potential. Very low
desorption of 0.4% and 0.2% estrogen hormones was observed from municipal biosolids and SMC, respectively. An estimate of
total estrogen contribution from different solid waste sources is reported. Animal manures (PM and CM) contribute to a significant
load of estrogen hormones in the natural environment. 相似文献
593.
A differential pulse polarography (DPP) for the simultaneous determination of 2-nitrophenol and 4-nitrophenol was proposed.
It was found that under optimum experimental conditions (pH = 5, scan rate = 5 mV/s, pulse amplitude = −50 mV), 2-nitrophenol
and 4-nitrophenol had well-defined polarographic reduction waves with peak potentials at −317 and −406 mV, respectively. In
the mixture of two compounds overlapping polarographic peaks were observed. In this study, support vector regression (SVR)
was applied to resolve the overlapped polarograms. Furthermore, a comparison was made between the performance of SVR and partial
least square (PLS) on data set. The results demonstrated that SVR is a better well-performing alternative for the analysis
and modeling of DPP data than the commonly applied PLS technique. The proposed method was used for the determination of 2-nitrophenol
and 4-nitrophenol in industrial waste water. 相似文献
594.
Assessment of drinking water quality using ICP-MS and microbiological methods in the Bholakpur area,Hyderabad, India 总被引:1,自引:0,他引:1
Abdul RM Mutnuri L Dattatreya PJ Mohan DA 《Environmental monitoring and assessment》2012,184(3):1581-1592
A total of 16 people died and over 500 people were hospitalized due to diarrhoeal illness in the Bholakpur area of Hyderabad,
India on 6th May 2009. A study was conducted with immediate effect to evaluate the quality of municipal tap water of the Bholakpur
locality. The study consists of the determination of physico-chemical properties, trace metals, heavy metals, rare earth elements
and microbiological quality of drinking water. The data showed the variation of the investigated parameters in samples as
follows: pH 7.14 to 8.72, EC 455 to 769 μS/cm, TDS 303.51 to 515.23 ppm and DO 1.01 to 6.83 mg/L which are within WHO guidelines
for drinking water quality. The water samples were analyzed for 27 elements (Li, Be, B, Na, Mg, Al, Si, K, Ca, V, Cr, Mn,
Fe, Ni, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Ba and Pb) using inductively coupled plasma-mass spectrometry (ICP-MS).
The concentrations of Fe (0.12 to 1.13 mg/L), Pb (0.01 to 0.07 mg/L), Cu (0.01 to 0.19 mg/L), Ni (0.01 to 0.15 mg/L), Al (0.16
to 0.49 mg/L), and Na (38.36 to 68.69 mg/L) were obtained, which exceed the permissible limits of the World Health Organization
(WHO) for drinking water quality guidelines. The remaining elements were within the permissible limits. The microbiological
quality of water was tested using standard plate count, membrane filtration technique, thermotolerant coliform (TTC), and
most probable number (MPN) methods. The total heterotrophic bacteria ranged from 1.0 × 105 to 18 × 107 cfu/ml. Total viable bacteria in all the water samples were found to be too numerable to count and total number of coliform
bacteria in all water samples were found to be of order of 1,100 to >2,400 MPN index/100 ml. TTC tested positive for coliform
bacteria at 44.2°C. All the water samples of the study area exceeded the permissible counts of WHO and that (zero and minimal
counts) of the control site (National Geophysical Research Institute) water samples. Excessively high colony numbers indicate
that the water is highly contaminated with microorganisms and is hazardous for drinking purposes. Bacteriological pollution
of drinking water supplies caused diarrhoeal illness in Bholakpur, which is due to the infiltration of contaminated water
(sewage) through cross connection, leakage points, and back siphoning. 相似文献
595.
Montes AM González-Farias FA Botello AV 《Environmental monitoring and assessment》2012,184(3):1359-1369
The lagoon system of Navachiste-Macapule is located in northern Mexico, in the state of Sinaloa, with an area of 24,000 ha.
The main economic activity in the area is agriculture, and the lagoon lies next to the irrigation district ID-063 which covers
116,615 ha. The purpose of this study is to evaluate the levels of pollution generated by organochlorine pesticides (OC) in
the surface sediments of the lagoon and in the agricultural drains of the ID-063 that are supposedly transported into the
system as a result of agricultural activities and runoff from adjacent land. For this, between 2006 and 2007, 45 surface sediment
samples were collected (warm dry, rainy and cold dry) from 15 sampling sites, during the three climatic seasons. Of these,
eight were located inside the lagoon in marine conditions (salinity >31 PSU) and seven in the agricultural drains of the ID-063
in freshwater conditions (salinity <5 PSU). The average concentration of the OC in the sediments was 44.75 ng g − 1, among which the group of the alicyclic compounds presented the greatest concentrations. The average value of the total organic
carbon (TOC) in the sediments of the system was 0.90%. The sediments collected inside the lagoon had an average OC concentration
of 18.97 ng g − 1, and the predominant type of sediment was fine to very fine sand. The average OC concentration in the sediments collected
in the agricultural drains was 75.69 ng g − 1, where fine sediments (silt) were predominant. The presence of methoxychlor, endrin and heptachlor suggested that these compounds
were continuously used in the system, even though their use is forbidden in Mexico. 相似文献
596.
Coastal environments, such as marshes, dunes, or estuaries, are characterized by their high natural values that usually cause them to be subjected to high protection levels, affecting activities taking place within them. This is why the action in these spaces must be based on the use of proper techniques and approaches, which integrate ecology with practical engineering necessities. In this context, the Department of Sciences and Techniques of the Water and Environment of the University of Cantabria, through methods developed in the natural reserve of the Salt Marshes of Santoña and Noja, proposes the use of a working methodology based on the discipline of “ecosystem management” combined with the “adaptive management” methodologies; the application of mathematical, statistical, and specific predictive instruments; and the utilization of an “ecologic niche” as a union between the scientific knowledge of the littoral environments and the true actuation scale of the projects and activities carried out within them. 相似文献
597.
de Figueiredo DR Ferreira RV Cerqueira M de Melo TC Pereira MJ Castro BB Correia A 《Environmental monitoring and assessment》2012,184(1):471-485
The information on bacterial community composition (BCC) in Portuguese water bodies is very scarce. Cértima River (central
western Portugal) is known to have high levels of pollution, namely organic. In the present work, the BCC from a set of 16
water samples collected from Cértima River Basin and its main tributaries was characterized using 16S rDNA–denaturing gradient
gel electrophoresis, a culture-independent molecular approach. Molecular data were related to environmental parameters through
multivariate analysis to investigate potential impact of water pollution along the river. Principal component analysis using
environmental data showed a water quality gradient from more pristine waters (at the mountain tributaries) to waters with
increasingly eutrophic potential (such as Fermentelos Lake). This gradient was mainly defined by factors such as organic and
inorganic nutrient sources, electrical conductivity, hydrogen carbonate concentration, and pH. Molecular results showed variations
in BCC along Cértima River Basin but in the main river section, a Bacteroidetes phylotype (Flavobacterium sp.) proved to be dominant throughout the river course. Multivariate analysis suggests that spatial variation of BCC along
the Cértima River Basin depended mainly on parameters such as Chl a, total suspended solid (TSS), total organic carbon, electrical conductivity, and HCO
_boxclose^-_{3}^{-} levels. Bacteroidetes phylotypes were all related to higher electrical conductivity and HCO3-_{3}^{-} levels although some of these were also correlated with high SO42-_{4}^{2-} and others with high soluble reactive phosphorus, nitrate, TN, and Kjeld-N levels. The Gammaproteobacteria occurrence was correlated with high SO42-_{4}^{2-} levels. One of the Betaproteobacteria phylotypes showed to correlate with low redox potential (Eh) and high temperature, pH, TSS, and Chl a levels while another one showed a negative correlation with Chl a values. 相似文献
598.
Fernandes CE Das A Nath BN Faria DG Loka Bharathi PA 《Environmental monitoring and assessment》2012,184(5):2677-2689
We investigated the influence on bacterial community and biochemical variables through mechanical disturbance of sediment-akin
to small-scale mining in Kalbadevi beach, Ratnagiri, a placer-rich beach ecosystem which is a potential mining site. Changes
were investigated by comparing three periods, namely phase I before disturbance, phase II just after disturbance, and phase
III 24 h after disturbance as the bacterial generation time is ≤7 h. Cores from dune, berm, high-, mid-, and low-tide were
examined for changes in distribution of total bacterial abundance, total direct viability (counts under aerobic and anaerobic
conditions), culturability and biochemical parameters up to 40 cm depth. Results showed that bacterial abundance decreased
by an order from 106 cells g − 1 sediment, while, viability reduced marginally. Culturability on different-strength nutrient broth increased by 155% during
phase II. Changes in sedimentary proteins, carbohydrates, and lipids were marked at berm and dune and masked at other levels
by tidal influence. Sedimentary ATP reduced drastically. During phase III, Pearson’s correlation between these variables evolved
from non-significant to significant level. Thus, simulated disturbance had a mixed effect on bacterial and biochemical variables
of the sediments. It had a negative impact on bacterial abundance, viability and ATP but positive impact on culturability.
Viability, culturability, and ATP could act as important indicators reflecting the disturbance in the system at short time
intervals. Culturability, which improved by an order, could perhaps be a fraction that contributes to restoration of the system
at bacterial level. This baseline information about the potential mining site could help in developing rational approach towards
sustainable harnessing of resources with minimum damage to the ecosystem. 相似文献
599.
Ilijević K Gržetić I Živadinov I Popović A 《Environmental monitoring and assessment》2012,184(5):2805-2828
Seasonal spatial and temporal changes of selected eco-chemical parameters in section of the Danube River flowing through Serbia
were analyzed. Data for electrical conductivity (EC), dry and suspended matter, residue on ignition, chemical oxygen demand
(COD), biochemical oxygen demand (BOD-5), ultraviolet extinction, dissolved oxygen (DO), oxygen saturation, pH, nitrates,
total phosphorus, and nitrogen were collected between 1992 and 2006. The use of monthly medians combined with linear regression
and two-sided t test has been proven to be the best approach for resolving trends from natural variability of investigated parameters and
for determining trend significance. Patterns of temporal changes between different months were examined. It was also determined
that spatial trends of some parameters oscillate in predictable manner, increasing in one part of the year and declining in
the other. Regression slope coefficients, an excellent indicator for determining when the water quality is changing the most
along the course of the Danube, reach their maximum during summer for temperature (t), electric conductivity, nitrates, and total N, while in the same season suspended matter, COD, BOD-5, DO, and oxygen saturation
coefficients reach their minimum. Correlations for used data sets of selected parameters were analyzed for better understanding
of their behavior and mutual relations. It was observed that as Danube flows through Serbia, its general eco-chemical status
either stagnates or improves, but the rate of river self-purification often depends on the season of the year. 相似文献
600.
Spatial and seasonal distribution of nitrogen in marsh soils of a typical floodplain wetland in Northeast China 总被引:3,自引:0,他引:3
Bai J Wang Q Deng W Gao H Tao W Xiao R 《Environmental monitoring and assessment》2012,184(3):1253-1263
Horizontal and profile distributions of nitrogen in marsh soils in different seasons were studied in a typical site within
the Erbaifangzi wetland in Northeast China. Results showed that there was higher spatial heterogeneity for nitrate nitrogen
(NO3--_{3}^{-}-N) and ammonium nitrogen (NH4+_{4}^{+}–N), as well as available nitrogen (AN), in surface soils in July compared to that in September. Relative to July, the mean
nitrogen contents in surface soils were slightly higher in September; however, in November, soils contained significantly
lower NO3--_{3}^{-}-N and NH4+_{4}^{+}–N, higher AN, organic nitrogen (Org-N), and total nitrogen (TN). Except for mineral nitrogen, no significant differences
were observed between Org-N and TN contents in September and November. Nitrogen contents generally declined exponentially
with depth along soil profiles in three sampling dates (July, September, and November), except for a significant accumulation
peak of NO3--_{3}^{-}-N at the 20–30 cm depth in September. However, NH4+_{4}^{+}–N contents showed a vertical alternation of “increasing and decreasing” in both July and September, while nearly kept constant
with depth in November. The depth ranking of nitrogen showed the shallowest distribution for AN, followed by Org-N and TN,
while deeper distributions for NO3--_{3}^{-}-N and NH4+_{4}^{+}–N. TN, Org-N, and AN were significantly correlated with soil organic matter and total phosphorus. Soil pH values were significantly
correlated with TN and AN contents in surface soils. Clay contents showed significant correlations with nitrogen contents
except for NO3--_{3}^{-}-N in surface soils and NH4+_{4}^{+}–N in profile soils. However, soil moisture was not significantly correlated with nitrogen contents among all soil samples. 相似文献