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   332篇
  免费   0篇
安全科学   8篇
废物处理   6篇
环保管理   51篇
综合类   11篇
基础理论   54篇
污染及防治   105篇
评价与监测   70篇
社会与环境   24篇
灾害及防治   3篇
  2012年   33篇
  2011年   39篇
  2010年   7篇
  2009年   24篇
  2008年   34篇
  2007年   22篇
  2006年   33篇
  2005年   32篇
  2004年   22篇
  2003年   14篇
  2002年   16篇
  2001年   13篇
  2000年   6篇
  1999年   7篇
  1998年   2篇
  1997年   1篇
  1996年   3篇
  1995年   2篇
  1993年   6篇
  1992年   6篇
  1991年   2篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1987年   3篇
  1984年   1篇
排序方式: 共有332条查询结果,搜索用时 19 毫秒
241.
IntroductionWork-safety tension arises when workers perceive that working safely is at odds with effectively doing their jobs. We proposed that workers’ perceptions of work-safety tension would be associated with higher levels of perceived risk, which would, in turn, relate to worker injuries on the job.MethodGrocery store workers (n = 600) completed an online survey and organizational worker injury reports were obtained for a two-year period following the survey. Survey results were linked to subsequent worker injuries using hierarchical generalized linear modeling.ResultsWe found support for the proposed meso-mediation model: department work-safety tension predicted subsequent worker injuries, partially through an association with workers’ risk perceptions.ConclusionsSafety researchers and consultants and organizational leaders should look beyond typically-examined safety climate constructs, such as management commitment to safety, and pay particular attention to workers’ perceptions of work-safety tension.  相似文献   
242.
This paper elucidates the basic approach of determining the path coefficients and its significance in the road traffic noise annoyance. Path model not only outline the direct effect of the traffic noise on the nearby residents but also indicate the indirect effect via other variables. In this study seven variables were considered for determining road traffic noise annoyance. However the same would be equally applicable for other situations like aircraft noise, rail noise, and industry noise with the different variables. At the outset a priori path model was designed and then on the basis of the partial regression coefficient values for the different paths, the revised path model was developed. The standardized partial regression coefficients known as path coefficients, determine the strength of the linkage among variables. Some of the paths in the model were not statistically significant. Revised path models were developed by deleting the insignificant paths whose values were found above 5% level. In the revised path model, thus the direct and indirect effect due to a particular variable causing the road traffic noise annoyance could be observed.  相似文献   
243.
Caps and stipes of 141 fruiting bodies of Parasol Mushroom (Macrolepiota procera) and surface layer of soils collected from 11 spatially distant and background (pristine) areas in Northern Poland were analyzed for Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr, and Zn by inductively coupled plasma optical emission spectroscopy and cold vapor atomic absorption spectroscopy. In terms of bioconcentration and bioexclusion concept, K, Ag, Cu, Rb, and P were highly bioconcentrated in caps, and their bioconcentration factor values varied for the 11 sites between 120 and 500—67–420, 70–220, 10–170, and 45–100, respectively. Cd, Zn, Mg, and Na showed bioconcentration factors (BCFs) between 3.3 and 36, 3.7–15, 0.92–6.3, and 1.4–44 while Al, Ba, Ca, Co, Cr, Mn, Ni, Pb, and Sr were excluded (BCF < 1). The Parasol Mushroom is a species harvested in the wild, and its caps are of unique taste and can contain a spectrum of essential and hazardous mineral compounds accumulated at elevated concentrations, even if collected at the background (pristine) areas. These elevated mineral concentrations of the caps are due to the efficient bioconcentration potential of the species (K, Ag, Cu, Rb, P, Cd, Zn, Mg, and Na) and abundance in the soil substrates (Al, Ca, Fe, Mn). The estimated intake rates of Cd, Hg, and Pb contained in Parasol Mushroom’s caps show a cause for concern associated with these metals resulting from the consumption of between 300- and 500-g caps daily, on a frequent basis in the mushrooming season.  相似文献   
244.
Integration of algal biofuel production to wastewater anaerobic digestion infrastructure has the potential to increase biogas production, decrease high and variable internal nitrogen loads, and improve sludge digestibility and dewaterability. In this research, two species of microalgae, Spirulina platensis and Chlorella sp., were grown on sludge centrate and a centrate and nitrified wastewater effluent mixture. Harvested algae were co-digested with waste activated sludge (WAS) at varying ratios. High-growth (6.8 g m(-2) x d(-1)), nitrogen (36.5 g m(-3) x d(-1)), and phosphorus (6.5 g m(-3) x d(-1)) uptake rates were achieved with Chlorella on centrate. No growth was observed with S. platensis under the same conditions; however, both organisms grew well on the centrate and effluent mixture. Co-digestion of algae with WAS improved volatile solids reduction. Although co-digestion with S. platensis improved biosolids dewaterability, Chlorella had a slight negative effect on dewaterability compared to WAS alone. The efficiency of energy conversion from photons to biogas generated from Chlorella was estimated at 1.4%.  相似文献   
245.
Total mercury content has been determined in fruiting bodies of European Blushers and topsoils collected from 11 sites across Poland in 2006-2008. Mercury analysis was carried out using a validated analytical method and cold-vapour atomic absorption (CV-AAS). The European Blusher effectively accumulated mercury in fruiting bodies. The mean values of total mercury in caps of European Blushers from background (uncontaminated) areas were from 0.22 to 1.0 (0.067-3.2) and in stipes from 0.16 to 0.65 (0.071-2.7) μg/g dry weight. In topsoil beneath to fruiting bodies, the median Hg concentration at 10 sites in Northern Poland varied between 0.030 and 0.072 (0.0096-0.19) μg/g dw, and in one site in Southern Poland was 0.20 (0.079-0.34) μg/g dw. Data on Hg in European Blushers from different countries were reviewed. The mean concentrations of total Hg in caps of European Blushers from two "pristine" sites in northern part of Poland were ~1.0 μg/g dw. A meal made with 300-500 g of fresh caps of European Blushers collected at such sites (assuming 90% water content in caps) can result in Hg intake of 0.0003-0.0005 mg Hg/kg bm (assuming a 60 kg bm), which is a dose equipotent to a new provisional tolerable weekly intake (PTWI) value set for inorganic Hg.  相似文献   
246.

Introduction

The changes in photosynthetic pigments, chlorophyll fluorescence, protein content, and antioxidant enzymes were investigated in a foliose lichen Pyxine cocoes, which was subjected to increasing concentrations of arsenate.

Methods

The arsenate concentrations of 10, 25, 50, 75, 100, and 200???M were sprayed every alternate day on the lichen thallus. The thalli were then harvested on 10, 20, 30, and 45?days.

Results

The quantity of photosynthetic pigments exhibited a decreasing trend till 20?days but increased from 30?days onwards. Concomitantly, chlorophyll fluorescence also showed a decreasing trend with increasing arsenic treatment duration as well as concentration. The higher concentration of arsenate was found to be deleterious to the photosynthesis of lichen as the chlorophyll fluorescence and the amount of pigments decreased significantly. The protein content of lichen increased uninterruptedly as the concentration of arsenate as well as duration of treatment increased. The activities of superoxide dismutase and ascorbate peroxide increased initially at lower concentration of arsenate but declined at higher concentrations and longer duration of treatment.

Conclusions

The catalase activity was found to be most susceptible to arsenate stress as its activity started declining from very beginning of the experiment. P. cocoes also proved to be an excellent accumulator of arsenate whose concentration increased in the thallus corresponding to its increase in the treatment and duration. Thus, it can be utilized for active biomonitoring of arsenic pollution.  相似文献   
247.
The 2005 hurricane season caused extensive damage and induced a mass migration of approximately 1.1 million people from southern Louisiana in the United States. Current and accurate estimates of population size and demographics and an assessment of the critical needs for public services were required to guide recovery efforts. Since forecasts using pre-hurricane data may produce inaccurate estimates of the post-hurricane population, a household survey in 18 hurricane-affected parishes was conducted to provide timely and credible information on the size of these populations, their demographics and their condition. This paper describes the methods used, the challenges encountered, and the key factors for successful implementation. This post-disaster survey was unique because it identified the needs of the people in the affected parishes and quantified the number of people with these needs. Consequently, this survey established new population and health indicator baselines that otherwise would have not been available to guide the relief and recovery efforts in southern Louisiana.  相似文献   
248.
Flubendiamide is a new insecticide that has been found to give excellent control of lepidopterous pests of tomato. This study has been undertaken to develop an improved method for analysis of flubendiamide and its metabolite des-iodo flubendiamide and determine residue retention in tomato and soil. The analytical method developed involved extraction of flubendiamide and its metabolite des-iodo flubendiamide with acetonitrile, liquid-liquid partitioning into hexane-ethyl acetate mixture (6:4, v v?1) and cleanup with activated neutral alumina. Finally the residues were dissolved in gradient high pressure liquid chromatography (HPLC) grade acetonitrile for analysis by HPLC. The mobile phase, acetonitrile-water at 60:40 (v v?1) proportion and the wavelength of 235 nm gave maximum peak resolution. Using the above method and HPLC parameters described, nearly 100 % recovery of both insecticides were obtained. There was no matrix interference and the limit of quantification (LOQ) of the method was 0.01 mg kg?1. Initial residue deposits of flubendiamide on field-treated tomato from treatments @ 48 and 96 g active ingredient hectare?1 were 0.83 and 1.68 mg kg?1, respectively. The residues of flubendiamide dissipated at the half-life of 3.9 and 4.4 days from treatments @ 48 and 96 g a.i. ha?1, respectively and persisted for 15 days from both the treatments. Des-iodo flubendiamide was not detected in tomato fruits at any time during the study period. Residues of flubendiamide and des-iodo flubendiamide in soil from treatment @ 48 and 96 g a.i. ha?1 were below detectable level (BDL, < 0.01 mg kg?1) after 20 days. Flubendiamide completely dissipated from tomato within 20 days when the 480 SC formulation was applied at doses recommended for protection against lepidopterous pests.  相似文献   
249.
This paper provides data on baseline concentrations, interrelationships and bioconcentration potential of 12 metallic elements by King Bolete collected from 11 spatially distant sites across Poland. There are significant differences in concentrations of metals (Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr, Zn) and their bioconcentration potential in King Bolete Boletus edulis at 11 spatially distant sites surveyed across Poland. These have resulted from significant geographical differences in trace metal concentrations in a layer (0-10 cm) of organic and mineral soil underneath to fruiting bodies and possible local bioavailabilities of macro- (Ca, K, Mg, Na) and trace metals (Al, Ba, Cd, Cu, Fe, Mn, Sr, Zn) to King Bolete. The use of highly appreciated wild-grown edible King Bolete mushroom has established a baseline measure of regional minerals status, heavy metals pollution and assessment of intake rates for wild mushroom dish fanciers against which future changes can be compared. Data on Cd, Cu and Zn from this study and from literature search can be useful to set the maximum limit of these metals in King Bolete collected from uncontaminated (background) areas. In this report also reviewed are data on Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr and Zn accumulation in King Bolete.  相似文献   
250.
An indirect competitive enzyme-linked immunosorbent assay (ELISA) has been developed and optimized for atrazine determination in soil at different depths (0-10, 10-20, and 20-30 cm) before and after 48 h of application, corn shoot and cow milk samples collected from Dina farm, Egypt. This assay was based on a specific polyclonal antibodies (PAb) raised by immunizing New Zealand rabbits with an immunogen prepared by coupling 3-{4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine-2-yl} thiopropanoic acid to bovine serum albumin (BSA) via N-hydroxysuccinimide (NHS) active ester method. The sensitivity (estimated as IC?? value) was 17.5 μg mL?1 with a detection limit of 0.1 ng mL?1. The maximum atrazine concentration was found in soil especially in the deepest layer (325 and 890 μg kg?1 before and after application, respectively). Atrazine concentration in corn shoot was 333.28, μg kg?1 dry plant, while there was no detectable amount in milk. All samples screened by ELISA were validated by gas chromatography mass spectrometer procedure (GC/MS). Good correlation was achieved between the two methods (r = 0.997 for soil and 0.9814 for plant). This study demonstrates the utility and convenience of the simple, practical and cost-effective ELISA method in the laboratory for analysis of environmental samples. The method is ideal for the rapid screening of large numbers of samples in laboratories where access to GC/MS facilities, is limited or lacking.  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