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51.
In order to quantify the sources of chemical pollutants in the leachate from reclaimed wastes, chemical substances in 11 different types of industrial wastes were identified. Their elution behaviors were also investigated. Alkanes (5.3-890 ng g(-1)), benzenes (8.1-110 ng g(-1)), polyaromatic hydrocarbons (PAHs) (3.2-560 ng g(-1)), alcohols, steroids, phenol (7.1 ng g(-1)), ketones, furans (190-210 ng g(-1)), phthalates (8.9-560 ng g(-1)), benzoquinones, dibenzothiophene (190 ng g(-1)), benthiocarb (4.2 ng g(-1)), sulfur, nitrile compounds, amino compounds, amido compounds, pyridines, quinolines (1.8-15 ng g(-1)), isoquinolines, carbazoles, acridines, chlordenes (1.5-1.6 ng g(-1)) and nonachlors (1.1-1.6 ng g(-1)) were detected in 9 types of industrial wastes. The chemical substances detected in waste at the highest concentrations were alkanes, PAHs and phthalates. Water supply sludge, dust and brick garbage contained many kinds of chemical substances. The elution behaviors of specific chemical substances, COD and nutrients varied by characteristic and production process of each waste. Over 100 different compounds were detected in pyrolysis products including carbohydrate, carotynoid, amino acids, proteins, humic acids, lignin and combustion products.  相似文献   
52.
Objective: A cyclist assumes various cyclic postures of the lower extremities while pushing the pedals in a rotary motion while pedaling. In order to protect cyclists in collisions, it is necessary to understand what influence these postures have on the global kinematics and injuries of the cyclist.

Method: Finite element (FE) analyses using models of a cyclist, bicycle, and car were conducted. In the simulations, the Total Human Model of Safety (THUMS) occupant model was employed as a cyclist, and the simulation was set up such that the cyclist was hit from its side by a car. Three representative postures of the lower extremities of the cyclist were examined, and the kinematics and injury risk of the cyclist were compared to those obtained by a pedestrian FE model. The risk of a lower extremity injury was assessed based on the knee shear displacement and the tibia bending moment.

Results: When the knee position of the cyclist was higher than the hood leading edge, the hood leading edge contacted the leg of the cyclist, and the pelvis slid over the hood top and the wrap-around distance (WAD) of the cyclist's head was large. The knee was shear loaded by the hood leading edge, and the anterior cruciate ligament (ACL) ruptured. The tibia bending moment was less than the injury threshold. When the cyclist's knee position was lower than the hood leading edge, the hood leading edge contacted the thigh of the cyclist, and the cyclist rotated with the femur as the pivot point about the hood leading edge. In this case, the head impact location of the cyclist against the car was comparable to that of the pedestrian collision. The knee shear displacement and the tibia bending moment were less than the injury thresholds.

Conclusion: The knee height of the cyclist relative to the hood leading edge affected the global kinematics and the head impact location against the car. The loading mode of the lower extremities was also dependent on the initial positions of the lower extremities relative to the car structures. In the foot up and front posture, the knee was loaded in a lateral shear direction by the hood leading edge and as a result the ACL ruptured. The bicycle frame and the struck-side lower extremity interacted and could influence the loadings on lower extremities.  相似文献   

53.
This study investigated the accumulation features and temporal trends of PCDD/Fs, dioxin-like PCBs (DL-PCBs) and non-dioxin-like PCBs (NDL-PCBs) in the blubber of Baikal seals collected in 1992 and 2005. DL-PCBs (480-3600 ng/g) and NDL-PCBs (980-35,000 ng/g) were dominant contaminants. Concentrations of PCDDs and PCBs in males were significantly higher than in females. In males, age-dependent accumulation was observed for PCDDs, mono-ortho PCBs and NDL-PCBs. PCDFs and non-ortho PCBs showed no such trends, implying that exposure of seals to these contaminants has been decreasing in recent years. No decreasing temporal trend was observed for PCDDs, mono-ortho PCBs and NDL-PCBs, suggesting that Baikal seals are still exposed to PCDDs and PCBs. TEQs of PCDDs and mono-ortho PCBs in seals collected in 2005 accounted for 62-77% of total TEQs. The TEQ levels in 40% of the specimens exceeded the threshold level for immunosuppression observed in harbor seals (209 pg/g).  相似文献   
54.
Polybrominated diphenyl ethers (PBDEs) are one of the flame retardants widely used in plastics, textiles, electronic appliances, and electrical household appliances. In this study, PBDEs and organochlorine compounds (OCs) were determined in the archived samples from the Environmental Specimen Bank for Global Monitoring (es-BANK) at Ehime University. The blubber of cetaceans found stranded along the coasts of Japan, Hong Kong, the Philippines and India during the period from 1990 to 2001 were employed for chemical analysis to understand the present status of contamination and the specific accumulation of PBDEs. PBDEs were detected in all the cetacean samples analyzed, and concentrations were one or two orders of magnitude lower than for PCBs and DDTs. Concentrations of PBDEs ranged from a low value of 6.0 ng/g lipid wt. in spinner dolphin (Stenella longirostris) from India to a high value of 6000 ng/g lipid wt. in Indo-Pacific humpback dolphin (Sousa chinensis) from Hong Kong. No difference in PBDE levels between coastal and offshore species from Japan was observed, implying the existence of pollution sources in this region other than Japan. Highest concentrations of PBDEs were found in animals from Hong Kong, followed by Japan, and much lower levels from the Philippines and India, suggesting that developing nations may also have pollution sources of PBDEs. Geographical distribution of PBDEs in Asian waters was different from PCBs but similar to DDTs.  相似文献   
55.
A polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) method was employed to estimate the contamination sources of human enteroviruses and understand how their dominant strains vary in a wastewater treatment and reclamation system consisting of sewage collection, wastewater treatment with membrane bioreactor and open lakes for reclaimed water storage and reuse. After PCR–DGGE using a selected primer set targeting enteroviruses, phylogenetic analysis of acquired enterovirus gene sequences was performed. Enteroviruses identified from the septic tank were much more diverse than those from grey water and kitchen wastewater. Several unique types of enterovirus different from those in wastewater samples were dominant in a biological wastewater treatment unit. Membrane filtration followed by chlorination was proved effective for physically eliminating enteroviruses; however, secondary contamination likely occurred as the reclaimed water was stored in artificial lakes. Enterovirus 71 (EV71), a hand-foot-and-mouth disease (HFMD) viral pathogen, was detected mainly from the artificial lakes, implying that wastewater effluent was not the contamination source of EV71 and that there were unidentified non-point sources of the contamination with the HFMD viral pathogen in the reclaimed water stored in the artificial lakes. The PCR–DGGE targeting enteroviruses provided robust evidence about viral contamination sources in the wastewater treatment and reclamation system.  相似文献   
56.
Bangladesh has a large aerial extent of freshwater wetlands for her deltaic characteristics. In 1970, the total area of wetlands in Bangladesh is estimated to be 70000–80000 km2, approximately, i.e., 50 % of total national land area. In the recent years, most of these wetlands are being lost and degraded primarily because of flood control projects, irrigation and agricultural activities and others human interference. Unfortunately, over the last three decades in the name of wetland development, local habitats were not taken care of. In this paper, the stakeholder and scenario analyses are employed for measuring public views towards wetlands degradation in Bangladesh. Involvement of stakeholders helps reconcile their different conflicting interests in wetlands, hence creating a common understanding about the problem under study. An exploratory scenario analysis illustrates different themes fulfilled by the wetlands and their associated services in case study Chalan Beel. The Chalan Beel once covered an area of approximately 651,230 acres in 1967. Currently, the permanent flooded area of the Chalan Beel has been reduced to about 18,120 acres. The scenarios show that most of the wetlands in Bangladesh are converted into agricultural lands, settlements, roads, and highways. Aquatic plants and animals are lost and endangered due to human interference and natural disturbance. The government, policymakers and some private organizations are trying to design suitable policy for wetland management but they are not able to reach this goal. It is observed that the local and national policies are facing complexities to create an effective regime to set aside the wetlands management policy in Bangladesh. In this context, this paper proposed an Increased Public Awareness (IPA) policy model that could be pathways for both short and long-term solutions of wetlands degradation in developing nations like Bangladesh.  相似文献   
57.
This paper explores mitigation scenarios for toxic cyanobacteria blooms in Lake Kasumigaura is located about 60–90 km northeast of Tokyo, in the southeast of Ibaraki Prefecture, Japan. Dominant species of cyanobacteria (Microcystis aeruginosa, Microcystis viridis and Microcystis ichthyoblabe) produce highly potent toxins as (Microcystin-(Leucine + Arginine, MC-LR), Microcystin-(Arginine + Arginine, MC-RR) and Microcystin-(Tyrosine + Arginine, MC-YR) in the Lake. Toxin production is generally the result of two major factors-natural processes and human interferences. Both factors have an extreme influence on the generation of cyanobacteria toxins within lake ecosystems. To address these factors, we propose two concepts for mitigation. The first concept is intended for examining the natural process of toxin production behavior within the lake and the second concept is used for evaluating inflow of wastes and nutrients from human activities that form toxins. Our research aims to combine both strategies to mitigate impacts of toxins, by examining trends of cyanobacteria nutrient sources, buoyancy regulations that influence bloom formation, and the environmental conditions that spur blooms. This study proposes a simple IMPACT (Integrating Mitigation Policies for Aquatic Cyanobacteria Toxin) model for diminution strategies of harmful algal blooms and their toxins. A mixed-methods approach is employed, nested within the Environmental Systems Analysis (ESA) tools e.g. scenario analysis and stakeholder analysis. The quality of the lake is assessed through a combination of observation and field study analysis. The findings suggest that successful mitigation of cyanobacteria toxins is highly dependent on multi-functional, multi-stakeholder involvement, and relevant intergovernmental policy. Without integrating approaches among different stakeholders, diverse socioeconomic activists, local-national policymakers and effective policy measures, prevention of cyanobacteria toxin production within lakes becomes extremely complex and difficult. The proposed IMPACT model could be a decision framework for identifying suitable policies that mitigate cyanobacteria impacts.  相似文献   
58.
An alkaline comet assay and a micronucleus test were carried out on erythrocytes of the European chub, Squalius cephalus L., collected in spring and autumn in 2005 and 2006 at three sampling sites in River Sava, near Zagreb, Croatia. The results of comet assay showed the lowest genotoxic influence at the least polluted site, while higher DNA damage was observed at the polluted sites. Although the basal levels of DNA damage were elevated, a clear gradation of DNA damage was found due to pollution intensity in all sampling periods. The lowest cytogenetic damage as revealed by the micronucleus test (MNT) was observed as well at the least polluted site. High variations in MN frequency were observed between sampling periods, although the number of micronucleated erythrocytes was consistently the highest one at the polluted site. The comet assay as a biomarker of genotoxic effect exhibited higher sensitivity in discriminating the genotoxic capacity of studied polluted sites while the MNT was less sensitive. However, both tests should be used together in biomonitoring studies because they can reveal different aspects of DNA damage; comet assay, the early event of genotoxic exposure, and MNT, its final result as a mutagenic potential.  相似文献   
59.
Caenorhabditis japonica is a bacteriophagous nematode species that was discovered on the semi-social burrower bug, Parastrachia japonensis, which demonstrates egg-guarding and provisioning behaviors. To understand the life history of C. japonica in relation to P. japonensis, we demonstrated the specificity of this association and fluctuations in nematode number on the insect throughout the year. C. japonica dauer larvae (DL), larvae in a nonfeeding diapause stage, were predominantly found as clumps on the adult female insects but rarely found on the male insects in all populations examined. This female-biased association was consistent throughout the year, but after the nymphs hatched, nematodes were not detected on the mother insects showing provisioning behavior. DL appeared on the nymphs, and the number of DL on the newly emerged female insects gradually increased thereafter. C. japonica has never been detected on other invertebrates collected from the P. japonensis habitat thus far. Our data suggest that the life cycles of C. japonica and P. japonensis are synchronized.  相似文献   
60.
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