首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   767篇
  免费   10篇
  国内免费   4篇
安全科学   59篇
废物处理   42篇
环保管理   138篇
综合类   68篇
基础理论   230篇
环境理论   1篇
污染及防治   155篇
评价与监测   61篇
社会与环境   23篇
灾害及防治   4篇
  2023年   4篇
  2022年   7篇
  2019年   5篇
  2018年   8篇
  2017年   9篇
  2016年   17篇
  2015年   13篇
  2014年   19篇
  2013年   76篇
  2012年   23篇
  2011年   46篇
  2010年   31篇
  2009年   26篇
  2008年   28篇
  2007年   31篇
  2006年   50篇
  2005年   21篇
  2004年   18篇
  2003年   26篇
  2002年   33篇
  2001年   23篇
  2000年   27篇
  1999年   12篇
  1998年   15篇
  1997年   11篇
  1996年   12篇
  1995年   13篇
  1994年   10篇
  1993年   9篇
  1992年   9篇
  1991年   9篇
  1990年   11篇
  1989年   7篇
  1988年   8篇
  1987年   8篇
  1986年   9篇
  1985年   6篇
  1984年   11篇
  1983年   5篇
  1982年   9篇
  1981年   7篇
  1980年   9篇
  1979年   5篇
  1978年   8篇
  1977年   4篇
  1976年   5篇
  1975年   3篇
  1974年   5篇
  1973年   5篇
  1969年   3篇
排序方式: 共有781条查询结果,搜索用时 687 毫秒
581.
In response to the EU Landfill Directive and the challenge of mitigating climate change, the UK government (nationally and locally) must develop strategies and policies to reduce, recycle, compost and recover waste. Best practice services that yield high recycling rates, such as alternate weekly collections, are now largely mainstream in suitable areas. However, national recycling performance is short of what is needed; policy makers must look for innovative ways to meet challenging recycling targets.Increasingly, local authorities are using behaviour change interventions to encourage the public to recycle; these tend to be based on the premise that an individuals’ behaviour is predetermined by their values. In practice, this has led to a host of initiatives that attempt to change individuals’ behaviour without addressing situational barriers. In this paper, we argue that that a behaviour-centric approach has limited effectiveness. Using an analysis of the literature and studies that investigated recycling participation in the city of Portsmouth, we have identified three significant clusters that can facilitate effective recycling: infrastructure, service and behaviour (ISB). We present the ISB model - a tool that can be used by waste practitioners when planning interventions to maximise recycling to better understand the situation and context for behaviour. Analysis using the ISB model suggests that current best practice, “business as usual” interventions could realistically achieve a national recycling rate of 50%. If the UK is to move towards zero waste, policy makers must look “upstream” for interventions that change the situational landscape.  相似文献   
582.
Archived suspended sediment samples collected over the period 1980-2002 at Niagara-on-the-Lake in the Niagara river were analyzed to assess temporal trends in contaminants associated with historical industrial activities in the watershed (PCDDs/PCDFs, DLPCBs), compared to more modern industrial chemicals (PBDEs). The temporal trends for PCDDs/PCDFs and DLPCBs were generally similar, and showed a general trend toward decreasing concentrations, which was presumably due to implementation of control measures in the Niagara river watershed, including the remediation of hazardous waste facilities. The temporal trend in PBDEs contrasted with those of PCDDs/PCDFs and DLPCBs. Prior to 1988, PBDEs (sum of 16 congeners including deca-BDE) were generally detected at low-ppb concentrations, but showed a trend toward increasing concentrations over the period 1980-1988. After 1988, PBDE concentrations in the Niagara river showed a more rapidly increasing trend to a maximum of approximately 35 ng/g in 1995, with deca-BDE as the predominant congener detected. Samples collected over the period February 2003 to March 2004 at the head and mouth of the Niagara river were also analyzed for PBDEs; in all cases PBDE concentrations were higher at the mouth of the river at the outflow to Lake Ontario, indicating the Niagara river watershed is a source of PBDE contamination to Lake Ontario. However, PBDE concentrations in suspended sediments of the Niagara river were comparable to, or lower than, concentrations in bottom sediments in other industrialized/urbanized areas of the world. Based on these comparisons of global PBDE bottom sediment concentrations, the Niagara river watershed does not appear to be a significant local source of PBDEs to Lake Ontario, and concentrations in suspended sediments appear to be indicative of general PBDE contamination from a contamination of local, regional, and continental sources.  相似文献   
583.
The metabolism of the antibacterial fluoroquinolone drug flumequine by Cunninghamella elegans was investigated using cultures grown in Sabouraud dextrose broth with 308microM flumequine. The cultures were extracted with ethyl acetate; metabolites were separated by high-performance liquid chromatography and identified by mass spectrometry and proton nuclear magnetic resonance spectroscopy. Flumequine was transformed to two diastereomers of 7-hydroxyflumequine (23 and 43% of the total chromatographic peak area at 280nm) and 7-oxoflumequine (11% of the total peak area). This is the first time that the two 7-hydroxy diastereomers have been characterized structurally; the hydroxyflumequines are known to have less antimicrobial activity than flumequine.  相似文献   
584.

Background

Immigrant Latino day laborers working in residential construction are at particularly high risk of fatal and non-fatal traumatic injury and benefit from targeted training.

Objective

To understand the impact of a participatory, peer-facilitated health and safety awareness training customized to the needs of Latino day laborers.

Methods

Baseline surveys exploring exposures, PPE use, attitudes, work practices and work-related injuries were collected from more than 300 New Jersey Latino day laborers in construction prior to their participation in a one day (minimum of six hour) Spanish language health and safety training class. The classes, led by trained worker trainers, engaged participants in a series of tasks requiring teamwork and active problem solving focused on applying safe practices to situations they encounter at their worksites. Follow-up surveys were difficult to obtain among mobile day laborers, and were collected from 70 men (22% response rate) 2-6 months following training. Chi-square analysis was used to compare pre- and post-intervention PPE use, self protective actions, and self-reported injury rates. Focus groups and in-depth interviews addressing similar issues provided a context for discussing the survey findings.

Results

At baseline, the majority of day laborers who participated in this study reported great concern about the hazards of their work and were receptive to learning about health and safety despite limited influence over employers. Changes from baseline to follow-up revealed statistically significant differences in the use of certain types of PPE (hard hats, work boots with steel toes, safety harnesses, and visible safety vests), and in the frequency of self-protective work practices (e.g., trying to find out more about job hazards on your own). There was also a suggestive decrease in self-reported injuries (receiving an injury at work serious enough that you had to stop working for the rest of the day) post-training based on small numbers. Sixty-six percent of workers surveyed post-training reported sharing information from their safety workbook with friends and co-workers. Focus groups and interview results generally confirmed the quantitative findings.

Conclusions

Participatory, peer led training tailored to the needs of construction day laborers may have a positive effect on Latino immigrant workers’ attitudes, work practices, and self reported injury rates, but major changes would require employer engagement.

Impact on Industry

Health and safety researchers have identified reducing the number of traumatic injuries among the immigrant construction workforce as an increasingly important priority. This project provides one model for collaboration between university-based researchers, a union, and a community-based organization. The specific elements of this project—participatory curriculum customized to the needs of day laborers in residential construction, training day laborers to facilitate training classes, and involving peer leaders in outreach and research—could be adapted by other organizations. The findings of this study suggest that the Latino day laborers have a strong interest in and some ability to act on health and safety information. Widespread implementation of this type of training, especially if supported with cooperation from residential contractors, could lead to reduced rates of traumatic injury in the residential construction industry.  相似文献   
585.
Aldehydes are an airborne byproduct of many industrialprocesses, vehicle transportation, and emissions fromnumerous natural sources. To characterize aldehydeconcentrations in ambient air of the Savannah, Georgiaarea, air samples for 3 aldehydes (formaldehyde,acetaldehyde, and propionaldehyde) were collected atfive sites on a monthly basis over a 12-month periodfrom December of 1995 through November 1996. Four ofthe sites were in central Savannah and the fifth sitewas located in a rural area about 56 km south ofSavannah. During each 24-hr sampling episode, sampleswere collected in two 12-hr periods approximatingdaylight and nighttime hours, following U.S. EPAMethod TO-11. Formaldehyde concentrations ranged from0.17 to 6.80 g m-3, acetaldehydeconcentrations ranged from 0.07 to7.60 g m-3, and propionaldehyde levels rangedfrom 0.02 to 9.10 g m-3. On average, thefour sites in Savannah had higher aldehydeconcentrations than the rural site (2.0 versus1.2 g m-3 for formaldehyde, 2.3 versus1.7 g m-3 for acetaldehyde, and 1.2 versus1.0 g m-3 for propionaldehyde). The daytimeconcentrations for formaldehyde and acetaldehyde werehigher than the nighttime levels. The data from allthe sites were within published worldwide backgroundvalues for aldehydes.  相似文献   
586.
Louisiana (LA) ranks fifth in the United States in cancer mortality rate. LA's infamous “cancer alley” is a well evidenced region near the southeast part of the Mississippi river surrounding the petrochemical hub of the state. LA has also experienced a high COVID-19 death rate and incidences compared to other states during the recent pandemic. In this study we analyzed publicly available datasets related to health and socio-economic parameters in LA to determine the factors triggering high incidences and deaths caused by COVID-19. Correlation analysis was performed to find the impact of different parameters on the outcome of COVID-19. Our analysis showed higher COVID-19 incidences in the parishes which are in and around the “cancer alley” with a correlation of r = 0.9. Interestingly, results also indicated a strong correlation (r = 0.9) between the death rates caused by asbestos toxicity to COVID-19 caused death rate. Furthermore, we found that office-administration related employment has a positive correlation to COVID-19 incidences in the “cancer alley.” However, we also found both white and black races are equally affected by the COVID-19 pandemic in the “cancer alley” region. In conclusion, our analysis strongly suggests that inhabiting “cancer alley” could significantly enhance the chances of getting affected by SARS-CoV-2 virus compared to other regions in LA.  相似文献   
587.
Mobile species may actively seek refuge from stressful conditions in biogenic habitats on rocky shores. In Hong Kong, the upper intertidal zone is extremely stressful, especially in summer when organisms are emersed for long periods in hot desiccating conditions. As a result, many species migrate downshore between winter and summer to reduce these stressful conditions. The littorinids Echinolittorina malaccana and E. vidua, for example, are found on open rock surfaces high on the shore in winter but the majority migrate downshore in summer to the same tidal height as a common barnacle, Tetraclita japonica. In the laboratory, where environmental conditions could be controlled to approximate those occurring on the shore, we tested whether the downshore migration allowed littorinids to select barnacles as biogenic habitats to reduce stress and if this behaviour varied between seasons. In summer, littorinids demonstrated a strong active preference for the barnacles, which was not observed in the cool winter conditions, when animals were found on open rock surfaces even when barnacles were present. Littorinids, therefore, only actively select biogenic habitats during the summer in Hong Kong when they migrate downshore, suggesting that such habitats may play an important, temporal, role in mitigating environmental stress on tropical shores.  相似文献   
588.
Studies of the importance of ecosystem engineers have focused on their benefit to biodiversity through ameliorating environmental stress, without understanding the exact benefits gained by associated organisms. On monsoonal tropical shores, species experience strong seasonality in environmental conditions from almost temperate winters to tropical summers when mass mortalities can occur during daytime emersion. The limpet, Cellana grata, associates with an ecosystem engineer, the barnacle Tetraclita japonica, in summer, but not in winter. To understand the benefits of this association, physiological responses (heart rates and osmotic responses) of the limpet either amongst Tetraclita or on open rock surfaces were investigated under three environmental conditions in a laboratory mesocosm: awash (non-stressed), low (30 °C) and high thermal stress (40 °C) of varying durations (3 or 6 h). In general, at 30 °C, limpets showed similar physiological responses under all conditions for both exposure durations. After 6 h at 40 °C, however, all limpets on open rock surfaces died, whereas those associated with barnacles survived. The surviving limpets experienced similar levels of stress as those exposed to 40 °C on open rock surfaces for half the time (3 h), showing that both the level and duration of stress were important. Limpets, therefore, gain benefits from engineering species when conditions are extreme or stress is prolonged. Under low temperatures or for short durations (e.g. winter), associating with barnacles does not provide physiological benefits. Understanding how, and to what extent, associates benefit from ecosystem engineers highlights how close the margin between survival and mortality can be when conditions are extreme.  相似文献   
589.
From 1998 to 2008, 68 adult female loggerhead sea turtles (Caretta caretta) were instrumented with platform transmitter terminals at nesting beaches in Georgia, North Carolina (NC) and South Carolina (SC) on the East Coast of the United States of America (30°48′N, 81°28′W to 33°51′N, 77°59′W). The majority of post-nesting loggerheads (N = 42, 62 %) migrated to foraging habitats in the Mid-Atlantic Bight during May–October, with a subsequent migration occurring during November–March to foraging habitats south of Cape Hatteras, NC. Nine (13 %) loggerheads initially foraged in the near-shore, coastal areas of the South Atlantic Bight, but moved to offshore habitats—closer to the Gulf Stream—during November–March, while fourteen (21 %) loggerheads remained in foraging areas along the mid-continental shelf off of the eastern coast of Florida and/or continued southward to Florida Bay and the Bahamas. The present study delineates important, post-nesting foraging habitats and migration corridors where loggerheads may interact with commercial fisheries—providing managers opportunities to develop and implement optimally effective conservation actions for the recovery of this threatened species.  相似文献   
590.
A method for sampling and analysis of phenolic compounds in workplace atmospheres using Amberlite XAD‐2 sorbent tubes has been laboratory and field tested. After extraction of the adsorbed phenols with methylene chloride, the concentrated extract was analyzed by capillary column gas chromatography coupled with a flame ionization detector or a mass spectrometer. For a 3L air sample, the method has a detection limit for phenol, cresols, alkyl‐substituted phenols and xylenols of 0.3 mg/m3 using gas chromatography with flame ionization detection (GC/FID) analysis and 0.07 mg/m3 using gas chromatography mass spectroscopy/selected ion monitoring GC‐MS/SIM. Evaluation tests conducted in the laboratory indicated recoveries >85% for a wide range of phenols, cresols, xylenols and other alkyl‐substituted phenols and resorcinol. Sampling conditions were established to ensure that no breakthrough occurred for a predetermined sample volume of three (3) liters even in humid atmospheres. Stability tests indicated that for storage of up to 2 weeks at 4°C, only resorcinol showed a significant reduction in sample recovery. The proposed method and NIOSH Method 3502 were compared for the determination of phenol concentrations in air samples collected at a plant processing phenolic resins. Phenol was positively identified in the XAD sample using GC‐MS/SIM and was detected at concentrations of 40–50% of the total phenols detected using NIOSH Method 3502. This difference is attributed to the airborne paniculate matter which is known to contain bisphenols that will contribute to the total phenolic content sampled in Method 3502, but not on the XAD sample.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号