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41.
Environmental Science and Pollution Research - The adverse effects of air pollution on the cardiovascular system have been well documented. Nonalcoholic fatty liver disease (NAFLD) is an...  相似文献   
42.
Environmental Science and Pollution Research - The concepts of the cities we know nowadays, and which we are accustomed to, change at a very rapid pace. The philosophy of their design is also...  相似文献   
43.
Abstract

Objective: To meet increasing customer demand, many vehicle manufacturers are now offering a panoramic sunroof option in their vehicle lineup. Currently, there is no regulatory or consumer test aimed at assessing the potential for ejection mitigation of roof glazing, which leaves manufacturers to develop internal performance standards to guide designs. The goal of this study was to characterize the variety of occupant-to-roof impacts involving unbelted occupants in rollover crashes to determine the ranges of possible effective masses and impact velocities. This information can be used to define occupant retention requirements and performance criteria for roof glazing in occupant ejection protection.

Methods: This study combined computational (MADYMO and LS-Dyna) simulations of occupant kinematics in rollover crashes with laboratory rollover crash tests using the dynamic rollover test system (DRoTS) and linked them through controlled anthropomorphic test device (ATD)-to-roof (“drop”) impact tests. The DRoTS and the ATD drop tests were performed to explore impact scenarios and estimate dummy-to-roof impact impulses. Next, 13 sets of vehicle kinematics and deformation data were extracted from a combination of vehicle dynamics and finite element model simulations that reconstructed variations of rollover crash cases from the field data. Then occupant kinematics data were extracted from a full-factorial sensitivity study that used MADYMO simulations to investigate how changes in anthropometry and seating position would affect occupant–roof impacts across all 13 cases. Finite element (FE) simulations of ATD and Global Human Body Models Consortium (GHBMC) human body model (HBM) roof impacts were performed to investigate the most severe cases from the MADYMO simulations to generate a distribution of head-to-roof impact energies.

Results: From the multiparameter design of experiment and experimental study, kinematics and energy output were extracted and analyzed. Based on dummy-to-roof impact force and dummy-to-roof impact velocity, the most severe rollover scenarios were identified. In the DRoTS experiments followed by the drop tests, the range of identified impact velocities was between 2 and 5.8 m/s. However, computational simulations of the rollover crashes showed higher impact velocities and similar effective masses. The largest dummy-to-roof impact velocity was 11 m/s.

Conclusions: This study combined computational and experimental analyses to determine a range of possible unbelted occupant-to-roof impact energies. These results can be used to determine design parameters for an impactor for the assessment of the risk of roof glazing ejection for unbelted occupants in rollover crashes.  相似文献   
44.
Results are presented for 137Cs, 90Sr and plutonium activity concentrations in more than 20 samples of terrestrial invertebrates, including species of beetles, ants, spiders and millipedes, collected in the highly contaminated area of the Chernobyl exclusion zone. The majority of samples were collected in Belarus, with some also collected in the Ukraine. Three other samples were collected in an area of lower contamination. Results show that seven samples exceed an activity concentration of 100 kBq/kg (ash weight - a.w.) for 137Cs. The maximum activity concentration for this isotope was 1.52 ± 0.08 MBq/kg (a.w.) determined in ants (Formica cynerea). Seven results for 90Sr exceeded 100 kBq/kg (a.w.), mostly for millipedes. Relatively high plutonium activity concentrations were found in some ants and earth-boring dung beetles. Analyses of activity ratios showed differences in transfer of radionuclides between species. To reveal the correlation structure of the multivariate data set, the Partial Least-Squares method (PLS) was used. Results of the PLS model suggest that high radiocesium activity concentrations in animal bodies can be expected mainly for relatively small creatures living on the litter surface. In contrast, high strontium activity concentrations can be expected for creatures which conduct their lives within litter, having mixed trophic habits and a moderate lifespan. No clear conclusions could be made for plutonium.  相似文献   
45.
Principal component analysis (PCA) was applied to a data set containing the levels of indicator polychlorinated biphenyls (PCBs) in human milk of mothers living in the Wielkopolska region, Poland, in order to investigate the information captured in the PCB patterns and to elucidate the relationship between PCB concentrations in milk and donor characteristics. According to the obtained PCA results milk fat content was the most influential factor affecting the PCB levels in milk of the Wielkopolska cohort. The lifestyle data collected from the questionnaire completed by the donors appeared to have no influence on PCB concentrations in breast milk. The score plots revealed the PCB contents of milk were quite low and uniform with a few outliers, without discrimination observed either between the primipareous and secundipareous females or between donors from the urban and rural areas. Comparison of the PCB levels and profiles of human milk from the Wielkopolska region and from various European and Asian locations made by PCA reflected a generally low background exposure and indicated the possible reasons for the outlying of some samples. In order to enhance the chances of observing the relationship between donor habits and PCB levels in breast milk it was suggested that the questionnaire be redesigned to gather information about vegetable product consumption and indoor air exposure.  相似文献   
46.
47.
ABSTRACT

Persistent organic pollutants (POPs) are known to show endocrine disrupting (ED) activity, including interactions with hormone receptors. The aim of this work was to develop a bioassay applicable for evaluation of ED potency of highly lipophilic metabolites of POPs. To that end, a yeast-based bio-assay protocol was used. Estrogenic / androgenic activity of some native brominated biphenyl ethers (BDEs) / chlorinated biphenyls (CBs), and their hydroxylated / methoxylated metabolites was assessed. Since data (including potency compared to reference native hormones) obtained using different protocols vary, the possibility that yeast transforms POPs into some more potent compounds was first checked; it seems that no such transformation is important from the test applicability standpoint. The developed method was sensitive with EC50 values 6.5*10?11 M and 4.5*10?9 M calculated for E2 and DHT, respectively. Both CBs and BDEs show weak estrogenic activity negatively correlated with the degree of their halogenation, but their metabolites are significantly more potent xenohormones. 4-OH-2,2′,4′,6′-TeCB was the most potent estrogen receptor (ER) agonist among all tested compounds; its activity was only 1,000 times lower than that of native E2.  相似文献   
48.
The paper presents the application of the hyphenated technique - high-performance liquid chromatography with atomic absorption spectrometry detection with hydride generation (HPLC-HG-AAS) - in the determinations of inorganic forms of arsenic: As(III) and As(V) in the exchangeable fraction of flood deposits. The separation of analytical signals of the determined arsenic forms was obtained using an ion-exchange column in a chromatographic system with the atomic absorption spectrometer as a detector, at the determination limits of 5 ng g−1 for As(III) and 10 ng g−1 for As(V). Flood deposits were collected after big flood event in valley of the Warta river which took place in summer 2010. Samples of overbank deposits were taken in Poznań agglomeration and vicinity (NW Poland). The results of determinations of arsenic forms in the exchangeable fraction of flood deposits allowed indication of a hypothetical path of deposits migration transported by a river during flood and environmental threats posed by their deposition by flood.  相似文献   
49.
Johannesson K  Smolarz K  Grahn M  André C 《Ambio》2011,40(2):179-190
Environmental change challenges local and global survival of populations and species. In a species-poor environment like the Baltic Sea this is particularly critical as major ecosystem functions may be upheld by single species. A complex interplay between demographic and genetic characteristics of species and populations determines risks of local extinction, chances of re-establishment of lost populations, and tolerance to environmental changes by evolution of new adaptations. Recent studies show that Baltic populations of dominant marine species are locally adapted, have lost genetic variation and are relatively isolated. In addition, some have evolved unusually high degrees of clonality and others are representatives of endemic (unique) evolutionary lineages. We here suggest that a consequence of local adaptation, isolation and genetic endemism is an increased risk of failure in restoring extinct Baltic populations. Additionally, restricted availability of genetic variation owing to lost variation and isolation may negatively impact the potential for evolutionary rescue following environmental change.  相似文献   
50.
The aim of this study was to determine 19 elements contents and bioconcentration potential in fruiting bodies of Parasol Mushroom (Macrolepiota procera) collected from the Tucholskie Forest complex in Poland. Also discussed were Cd, Pb and Hg contents of edible caps in relation to the current regulatory standards. K, P and Mg were particularly abundant in caps and stipes, median values were 38-49, 13, and 1.6-1.6 mg/g dry weight, and followed by Ca, Na and Rb at 110-540, 44-240 and 20-50 μg/g dw, respectively. Concentrations of Al, Fe, Zn, Cu and Mn were from less than 50 to 180 μg/g dw, while concentrations of other elements were ~l.0?μg/g dw or less. Cu, K, Ag, Cd, Na, Rb, Zn and Hg were bioconcentrated (BCF >1), while Al, Ba, Fe, Mn, Co, Sr, Pb and Cr were not bioaccumulated (BCF <1). Cd and Pb content of Parasol Mushroom's edible caps collected from some sites in the Tucholskie Forest exceed the maximum levels set in the EU for cultivated mushrooms.  相似文献   
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