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161.
162.
Joana?MadureiraEmail author Inês?Paciência Jo?o?Rufo André?Moreira Eduardo?de?Oliveira Fernandes Alcides?Pereira 《Environmental geochemistry and health》2016,38(2):523-533
Radon is a radioactive gas, abundant in granitic areas, such as in the city of Porto at the north-east of Portugal. This gas is a recognized carcinogenic agent, being appointed by the World Health Organization as the leading cause of lung cancer after smoking. The aim of this preliminary survey was to determine indoor radon concentrations in public primary schools, to analyse the main factors influencing their indoor concentration levels and to estimate the effective dose in students and teachers in primary schools. Radon concentrations were measured in 45 classrooms from 13 public primary schools located in Porto, using CR-39 passive radon detectors for about 2-month period. In all schools, radon concentrations ranged from 56 to 889 Bq/m3 (mean = 197 Bq/m3). The results showed that the limit of 100 Bq/m3 established by WHO IAQ guidelines was exceeded in 92 % of the measurements, as well as 8 % of the measurements exceeded the limit of 400 Bq/m3 established by the national legislation. Moreover, the mean annual effective dose was calculated as 1.25 mSv/y (ranging between 0.58 and 3.07 mSv/y), which is below the action level (3–10 mSv). The considerable variability of radon concentration observed between and within floors indicates a need to monitor concentrations in several rooms for each floor. A single radon detector for each room can be used, provided that the measurement error is considerably lower than variability of radon concentration between rooms. The results of the present survey will provide useful baseline data for adopting safety measures and dealing effectively with radiation emergencies. In particular, radon remediation techniques should be used in buildings located in the highest radon risk areas of Portugal. The results obtained in the current study concerning radon levels and their variations will be useful to optimize the design of future research surveys. 相似文献
163.
164.
Naja Brandão Santana Daisy Aparecida do Nascimento Rebelatto Ana Elisa Périco Enzo Barberio Mariano 《国际发展与全球生态学杂志》2014,21(3):259-272
There is much concern about the social and environmental impacts caused by the economic growth of nations. Thus, to evaluate the socio-economic performance of nations, economists have increasingly addressed matters related to social welfare and the environment. It is within the scope of this context that this work discusses the performance of countries in the BRICS group regarding sustainable development. The objective of this study regards evaluating the efficiency of these countries in transforming productive resources and technological innovation into sustainable development. The proposed objective was achieved by using econometric tools as well as the data envelopment analysis method to then create economic, environmental, and social efficiency rankings for the BRICS countries, which enabled to carry out comparative analyses on the sustainable development of those countries. The results of such assessments can be of interest for more specific scientific explorations. 相似文献
165.
Ana P. Gomes João F. Mano João A. Queiroz Isabel C. Gouveia 《Journal of Polymers and the Environment》2012,20(4):1084-1094
The introduction of molecules with biological properties on textile materials is essential for a number of biotechnological applications. With the purpose of testing new processes applied to textiles, in this study, we present the first results on the feasibility of using the Layer-by-Layer (LbL) deposition process in natural fibers such as cotton, with natural polyelectrolytes like chitosan (CH) and alginic acid sodium salt (ALG), the durability of CH/ALG multilayer on cotton were evaluated. The increase of negative charges to the substrate cotton was made with NaBr and TEMPO, to ensure the success of the process of LbL. Three characterization methods to assess electrostatic LbL deposition were performed: the contact angle between a liquid (water) and the sample surface, in order to characterize the wettability of the samples with the different layers of CH and ALG; dyeing of the CH/ALG assembled cotton fabric with cationic methylene blue that shows regular changes in terms of color depth (K/S value), which indicate that the surface were alternately deposited with CH and ALG layers and, finally, the analysis by infrared spectroscopy using Fourier Transform with Attenuated Total Reflection (ATR-FTIR), to assess the changes in the interaction between CH and ALG deposited on cotton samples. 相似文献
166.
Christian Luis Rodriguez-Enriquez Eduardo Tadeo Juan Rull 《Behavioral ecology and sociobiology》2013,67(6):937-946
Postcopulatory processes can influence male reproductive success in several animal species. Females can use different mechanisms to bias male paternity after copulation. One of such mechanisms consists in expelling all or part of the ejaculate after copulation. Euxesta bilimeki is an Ulidiid fly whose females not only frequently expel ejaculates after mating but also consume the ejaculate after expulsion. In order to understand the significance of these behaviors we examined video recordings of courtship, copulatory, and postcopulatory behaviours. The presence of sperm in female storage organs was confirmed after mating with males of different sizes and was correlated with duration of courtship, copulation, and the period from the end of copulation to ejaculate expulsion. The effect of ejaculate consumption on female fitness (fecundity and longevity) was compared among females held under different dietary treatments: a rich diet consisting of protein, sugar and water, an intermediate diet composed of sugar and water, a poor diet of only water and females that were completely deprived of food and water. All of the observed females expelled ejaculates after mating. The probability of storing sperm in the two spermathecae and the ventral receptacle was correlated with interactions between the duration of all behaviours examined and male size. Except for starved females, who lived longer when allowed to consume ejaculates, ejaculate consumption had no effect on fitness. Results suggest that females can bias sperm storage according to male mating effort, while the consumed ejaculate had some nutritional value only evident when females were completely starved. 相似文献
167.
Quantitative assessment of the differential coastal vulnerability associated to oil spills 总被引:1,自引:0,他引:1
Catarina Frazão Santos Rui Carvalho Francisco Andrade 《Journal of Coastal Conservation》2013,17(1):25-36
The risk associated with a given hazard (natural or technological) generally results from the interaction between the hazard potential and the vulnerability. This paper is centred on the assessment of the vulnerability variable. A quantitative vulnerability assessment and mapping methodology is proposed, with two main specificities: (1) it is hazard- and spatially-centred (respectively, oil spills and coastal areas) and; (2) the spatial segregation level used is the municipality. Due to the geographic context of the Portuguese mainland coast, the proposed methodology was applied in an attempt to illustrate the spatial distribution and the degree of the vulnerability associated to oil spills for mainland Portugal coastal municipalities. A final map is presented together with other informative elements. Analysis and discussion of the results allows for the understanding that: (1) there is a very heterogeneous and differential distribution of the degree of vulnerability to oil spills along the Portuguese coastline; (2) the application of specific hazard-centred and spatially-centred vulnerability assessment methodologies, comprising multi-dimensional indicators (e.g., geographic, ecological, demographic, social and economic), produces more robust and realistic results, highlighted by a thorough and spatially detailed analysis; and (3) future research is required on vulnerability assessment in Portugal; along side, hazard potential assessment methodologies must also be developed in order to create a final risk profile, which can be an extremely useful tool in spatial planning and management. 相似文献
168.
Arsenic bioaccessibility in a gold mining area: a health risk assessment for children 总被引:1,自引:0,他引:1
Ono FB Guilherme LR Penido ES Carvalho GS Hale B Toujaguez R Bundschuh J 《Environmental geochemistry and health》2012,34(4):457-465
High concentrations of total arsenic (As) have been measured in soils of gold mining areas of Brazil. However, bioaccessibility tests have not yet been conducted on those materials, which is essential for better health risk estimates. This study aimed at?evaluating As bioaccessibility in samples from a gold mining area located in Brazil and assessing children's exposure to As-contaminated materials. Samples were collected from different materials (a control and four As-contaminated soils/sediments) found in a gold mine area located in Paracatu (MG), Brazil. Total and bioaccessible As concentrations were determined for all samples. The control soil presented the lowest As concentrations, while all other materials contained high total As concentrations (up to 2,666?mg?kg(-1)) and low bioaccessible As percentage (<4.2%), indicating a low risk from exposure of resident children next to this area. The calculated dose of exposure indicated that, except for the pond tailings, in all other areas, the exposure route considering soil ingestion contributed at most to 9.7% of the maximum As allowed ingestion per day (0.3?μg?kg(-1) BW day(-1)). 相似文献
169.
Judith?MoralesEmail author Roxana?Torres Alberto?Velando 《Behavioral ecology and sociobiology》2012,66(1):135-143
In evolutionary biology, whether parents should enhance or reduce parental care according to mate ornamentation is a subject
of great debate. However, the evolution of female ornaments can shed light on this question. In theory, female ornamentation
should be traded off against fecundity and thus cannot be wholly informative to males without a direct indication of fecundity.
Hence, direct cues of offspring quality should affect the relationship between male investment and female ornamentation. Under
this hypothesis, we manipulated two direct cues of offspring quality (egg size and color) after first egg laying in the blue-footed
booby and registered male incubation patterns. In this species, foot color is a dynamic signal of current condition and in
females is traded off with egg size. We found that males spent more time incubating when paired with dull females but only
in nests with large eggs. Males also spent less time incubating small dull eggs. Results indicate that egg size, a direct
cue of reproductive value, affected the relationship between male effort and female ornamentation. Males may be willing to
help females that have invested in offspring at the expense of ornamentation, which suggests compensation when females are
in low condition. Another possibility is that males relax their effort when paired with highly ornamented and fecund females
because they have high parenting abilities. Our findings suggest that the information conveyed by female ornaments may depend
on direct cues of fecundity. Results also highlight that parental decisions are complex, modulated by a combination of information
sources. 相似文献
170.
Maren?HuckEmail author Eduardo?Fernandez-Duque 《Behavioral ecology and sociobiology》2012,66(3):505-517
According to the Evolutionary Theory of the Family, the replacement of one pair-member by an intruder may have profound consequences
for the existing offspring. Step-parents are expected to provide less care towards unrelated immatures than to genetic offspring,
unless caring also serves as a mating strategy. Furthermore, because an intruder will be a potential mate for opposite-sexed
offspring, relationships between offspring and same-sex parents are predicted to deteriorate. To test these predictions, we
studied an Azara’s owl monkey (Aotus azarai) population in Argentina exhibiting serial monogamy and bi-parental care. Since 1997, we have collected demographic data
from ca. 25 groups and inter-individual distance data from ca. 150 marked individuals. First, we compared survival and dispersal
age of immatures in groups with and without replacements to investigate whether parental care serves as a mating strategy.
Second, we compared sex-specific age at dispersal for groups with replacement of opposite-sex parents, same-sex parents, or
in stable groups in order to test whether relationships between offspring and same-sex parents deteriorated after the replacement
of the other parent. Survival and dispersal ages were not negatively associated with replacements, suggesting that male care
might serve, at least partly, as a mating strategy. The time lag between a replacement and the subsequent dispersal of female
offspring was greater if the intruder was a male, while the offspring and same-sex parents were less often nearest neighbors
after replacements than before. Our results suggest that family disruption through the replacement of a parent is not associated
with decreased offspring survival or early dispersion of juveniles, but deteriorates parent–offspring relationships. 相似文献