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21.
Kodagu district produces 2% of the world’s coffee, in complex, multistoried agroforestry systems. The forests of the district
harbour a large population of the Asian elephant (Elephas maximus). The combined effects of high elephant density and major landscape changes due to the expansion of coffee cultivation are
the cause of human–elephant conflicts (HEC). Mitigation strategies, including electric fences and compensation schemes implemented
by the Forest Department have met with limited success. Building on previous studies in the area, we assessed current spatial
and temporal trends of conflict, analysed local stakeholders’ perceptions and identified factors driving elephants into the
estates. Our study, initiated in May 2007, shows that the intensity of HEC has increased over the last 10 years, exhibiting
new seasonal patterns. Conflict maps and the lack of correlation between physical features of the coffee plantations and elephant
visits suggest elephants move along corridors between the eastern and western forests of the district, opportunistically foraging
when crossing the plantations. Dung analyses indicate elephants have selectively included ripe coffee berries in their diet.
This is, to our knowledge, the first report of wild elephants feeding on coffee berries. If this new behaviour spreads through
the population, it will compound an already severe conflict situation. The behavioural plasticity, the multiplicity of stakeholders
involved, the difficulty in defining the problem and the limits of technical solutions already proposed suggest that HEC in
Kodagu has the ingredients of a “wicked” problem whose resolution will require more shared understanding and problem solving
work amongst the stakeholders. 相似文献
22.
Domokos E Holenda B Utasi A Rédey A Fazakas J 《Environmental science and pollution research international》2005,12(5):306-309
- Goals. The objective of the paper is to illustrate the solution of a chronic problem occurring in a wastewater treatment facility
with a capacity of 12,000 inhabitant equivalent. A drastic phosphorus concentration increase (two or three times higher than
the Hungarian limit of 1 mg/l) was observed in the wastewater treatment facility for a long time (12–24 h) with changing time
periods indicating malfunctioning in the operation of the facility.
Methods Computer-aided simulation technique was used to develop a solution for the treatment of the problem using a software developed
by the Department of Environmental and Chemical Engineering, University of Veszprém, Hungary.
Results and Discussion The simulation studies show that if the nightly inflow is less than 200 m3/h at least for two hours, the system doesn't then
receive enough fresh nutrients which can cause a deficiency in the nutrient uptake of the PAOs in the anaerobic zones. This
can result in the fact that the PAOs accumulate less phosphorus into the aerobic zones.
Conclusion Long retention time (10 h) is the reason for the problem, namely – under special conditions – the phosphorus in the sludge
of the settling tank of the wastewater treatment plant. The problem was caused by phosphorus dissolution from the sludge of
the settling tank during the undesirably long retention time. 相似文献
23.
János Török Rita Hargitai Gergely Hegyi Zoltán Matus Gábor Michl Péter Péczely Balázs Rosivall Gyula Tóth 《Behavioral ecology and sociobiology》2007,61(4):541-550
Birds may influence the fitness of their offspring by transmission of different amounts of carotenoids to their eggs. Carotenoids
play crucial roles in antioxidant protection and immune defence mechanisms, but they may be available to females in limiting
amounts. Therefore, their allocation to the eggs may be influenced by the female’s condition, age and environmental circumstances.
Furthermore, the quality of the male parent, which affects the reproductive value of the offspring, may also influence this
investment. In this correlational study, we investigated proximate and ultimate factors that may lead to variation in yolk
lutein, zeaxanthin and β-carotene concentrations among and within clutches of a wild passerine, the collared flycatcher (Ficedula albicollis). We found that carotenoid concentration was positively associated with caterpillar supply at the time of egg formation,
which suggests a proximate constraint of carotenoid availability on yolk composition. Neither female condition, body size,
age, nor male plumage ornamentation, age and body size correlated with carotenoid deposition. Yolk β-carotene concentration
was found to be positively linked to yolk testosterone concentration. We suggest that females allocated more β-carotene to
their eggs to mitigate the potentially detrimental effects of elevated steroid concentration. We found that concentration
of β-carotene increased with laying order. The possible function of this pattern may be to enhance the resistance to oxidative
stress and pathogens of the disadvantaged last-hatching nestling, suggesting that collared flycatchers pursue a compensatory,
“brood survival” strategy. 相似文献
24.
25.
Paternal age and offspring growth: separating the intrinsic quality of young from rearing effects 总被引:2,自引:0,他引:2
Younger individuals are often less successful in reproduction than older ones. This might be because of improving breeding skills with age or because the genetic quality of young or early maternal effects on them vary with parental age. However, no attempt has been made to experimentally separate these processes in vertebrates. We conducted a cross-fostering experiment in collared flycatchers (Ficedula albicollis) in three breeding seasons to disentangle origin- and rearing-related effects of paternal age on chick growth, while controlling for date-specific environmental conditions as well as differences in clutch and brood size. The age of the male at the nest of origin, but not that of the rearing male, had a year-dependent effect on nestling body mass and tarsus length. In two seasons, young of subadult males grew slower in the early linear phase of growth than young of adult males. There was no compensatory growth in the final asymptotic phase, so both body mass and tarsus length before fledging reflected the differential early development. In the remaining year, the age of the male at the nest of origin had no significant effect on chick growth. The environment-dependent origin effect we detected was unexplained by incubation times, hatching asynchrony, chick masses at swapping or previously described age-dependent egg quality patterns. Our results therefore suggest a genotype × environment interaction on the relative development of offspring sired by subadult and adult males. Our results also raise the possibility that female birds may gain genetic benefits by mating with older males. Further studies should identify general patterns of male age-dependent female mate choice and offspring quality in different environmental conditions. 相似文献
26.
Eszter Szász László Zsolt Garamszegi Gergely Hegyi Eszter Szöllősi Gábor Markó János Török Balázs Rosivall 《Die Naturwissenschaften》2014,101(8):653-660
Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner’s behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher (Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies. 相似文献
27.
Ivan Dolezal Kausik Bal 《International journal of occupational safety and ergonomics》2019,25(4):562-567
Measurement of thermal resistance of polymer sheets and fibrous layers is important in various applications including those within the engineering, ergonomics, clothing design and personal protective equipment fields. Standard methods for measurement of thermal resistance of plain materials are generally time consuming, expensive and often require the sample to be cut. Moreover, the temperature difference between the surfaces of both plates surrounding the sample must be known, as well as the sample thickness. This article describes a new measuring device named the Thermoscope. The Thermoscope is not limited by the aforementioned requirements and is able to evaluate the thermal resistance of polymer sheets and textiles by touching the sample on one surface alone. Simultaneously, the other surface is kept in thermal contact with the supporting base. The accuracy of this device was compared with the Alambeta thermal insulation tester. Effects of various base materials on measurement precision were also studied. 相似文献
28.
Bakshi Payal Pappu Asokan Gupta Manoj Kumar 《Journal of Material Cycles and Waste Management》2022,24(1):49-62
Journal of Material Cycles and Waste Management - This study provides an overview of calcium rich industrial wastes usage in construction materials, their properties and different applications... 相似文献
29.
Miklós Laczi Gergely Hegyi Márton Herényi Dorottya Kiss Gábor Markó Gergely Nagy Balázs Rosivall Eszter Szöllősi János Török 《Die Naturwissenschaften》2013,100(10):983-991
The possible integration of different sexual ornaments into a composite system, and especially the information content of such ornament complexes, is poorly investigated. Many bird species display complex plumage coloration, but whether this represents one integrated or several independent sexual traits can be unclear. Collared flycatchers (Ficedula albicollis) display melanised and depigmented plumage areas, and the spectral features (brightness and UV chroma) of these are correlated with each other across the plumage. In a 5-year dataset of male and female plumage reflectance, we examined some of the potential information content of integrated, plumage-level colour attributes by estimating their relationships to previous and current year body condition, laying date and clutch size. Females were in better condition the year before they became darker pigmented, and males in better current year condition were also darker pigmented. Female pigment-based brightness was positively, while male structurally based brightness was negatively related to current laying date. Finally, the overall UV chroma of white plumage areas in males was positively associated with current clutch size. Our results show that higher degree of pigmentation is related to better condition, while the structural colour component is associated with some aspects of reproductive investment. These results highlight the possibility that correlated aspects of a multiple plumage ornamentation system may reflect together some aspects of individual quality, thereby functioning as a composite signal. 相似文献
30.
Bal Kumari Sharma Khanal Muhammad Bilal Sadiq Manisha Singh 《Journal of environmental science and health. Part. B》2018,53(1):57-86
The prevalence of two groups of antibiotics; namely penicillin and sulfonamides was studied in fresh milk available in Kathmandu Valley of Nepal. The milk samples (n = 140) were collected from three different sources; individual farmers, cottage dairies and organized dairies of Kathmandu valley. Qualitative and semi-quantitative analysis with rapid screening kits revealed that 23% samples were positive for antibiotic residues in the fresh milk for penicillin and sulfonamide groups (1–256 µg/kg). High performance liquid chromatography (HPLC) analyses detected 81% samples positive for amoxicillin (68–802 µg/kg), 41% for sulfadimethoxine (31–69 µg/kg), 27% for penicillin G (13–353 µg/kg), and 12% for ampicillin (0.5–92 µg/kg). Due to the precision and accuracy of liquid chromatography method, it detected more positive samples and consequently presented higher prevalence than the rapid screening kits. The antibiotic residues were found above the maximum residue limits that presented serious threat to consumer health and raised a serious concern regarding the implementation and monitoring of international regulations in developing countries. 相似文献