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   287篇
  免费   2篇
  国内免费   1篇
安全科学   9篇
废物处理   14篇
环保管理   39篇
综合类   61篇
基础理论   78篇
污染及防治   68篇
评价与监测   5篇
社会与环境   12篇
灾害及防治   4篇
  2023年   3篇
  2022年   4篇
  2021年   5篇
  2019年   4篇
  2018年   2篇
  2017年   10篇
  2016年   10篇
  2015年   8篇
  2014年   7篇
  2013年   18篇
  2012年   16篇
  2011年   9篇
  2010年   8篇
  2009年   13篇
  2008年   22篇
  2007年   15篇
  2006年   10篇
  2005年   14篇
  2004年   8篇
  2003年   11篇
  2002年   19篇
  2001年   4篇
  2000年   10篇
  1999年   4篇
  1998年   5篇
  1997年   5篇
  1995年   3篇
  1994年   5篇
  1993年   1篇
  1992年   4篇
  1989年   3篇
  1988年   1篇
  1987年   2篇
  1985年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1969年   2篇
  1962年   1篇
  1960年   2篇
  1959年   4篇
  1958年   2篇
  1957年   1篇
  1955年   1篇
  1954年   3篇
  1952年   1篇
排序方式: 共有290条查询结果,搜索用时 234 毫秒
11.
The present work focuses on the fate of two cancerostatic platinum compounds (CPC), cisplatin and carboplatin, as well as of two inorganic platinum compounds, [PtCl4]2− and [PtCl6]2− in biological wastewater treatment. Laboratory experiments modelling adsorption of these compounds onto activated sludge showed promising specific adsorption coefficients KD and KOC and Freundlich adsorption isotherms. However, the adsorption properties of the investigated substances were differing significantly. Adsorption decreased following the order cisplatin > [PtCl6]2− > [PtCl4]2− > carboplatin. Log KD-values were ranging from 2.5 to 4.3 , log KOC from 3.0 to 4.7.

A pilot membrane bioreactor system (MBR) was installed in a hospital in Vienna and fed with wastewater from the oncologic in-patient treatment ward to investigate CPC-adsorption in a sewage treatment plant. During three monitoring periods Pt-concentrations were measured in the influent (3–250 μg l−1 Pt) and the effluent (2–150 μg l−1 Pt) of the treatment plant using ICP-MS. The monitoring periods (duration 30 d) revealed elimination efficiencies between 51% and 63% based on averaged weekly input–output budgets. The derived log KD-values and log KOC-values ranged from 2.4 to 4.8 and from 2.8 to 5.3, respectively. Species analysis using HPLC-ICP-MS proofed that mainly carboplatin was present as intact drug in the influent and – due to low log KD – in the effluent of the MBR.  相似文献   

12.
Investigations of the dandelion, Taraxacum officinale Web. in Poland, Romania and Germany showed that the species concentrates various elements dependent on the intensity of the pollutants. In this study, we followed up the question of whether T. officinale enriches pollutants by the atmospheric deposition on the leaves or via the soil. Therefore, samples from at least 10 plants and a soil sample at 57 sample sites were collected from a grid of 500 m × 500 m. In addition to the analysis of the total soil sample, the (mobile) ion pool of the soil (DIN V 19739) was analysed. The elements Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, K, Mg, Mn, Mo, Na, Ni, Rb, Sr, Ti, Tl, V, and Zn were determined through the use of spectrometry with inductive coupled plasma (ICP-MS and ICP-OES). The results are compared with the element concentrations of washed and unwashed leaf samples in T. officinale. We could only find two direct correlations (Ti and Zn) between the element content, of the entire soil samples, but 14 correlations (As, Ba, Cd, Cu, Ga, K, Mn, Mo, Na, Ni, Rb, Ti, Tl und Zn) between the ion pool of the soil and the washed samples. The grid point data interpolation by ArcInfo showed a similar distribution pattern for the unwashed leaf elements Al, Ce, Fe, Ti and V (r≥0.75). The elements Al, Ce, Fe, Ti, and V are washed out at the same ratio. Thus, although the concentration of these elements were significantly reduced by the washing procedure, the correlations were not influenced. The admissibility of the grid point data interpolation for a distribution map of the town area was investigated, as well. It is shown that the element content varies with the land use (meadow, field, rural areas), the sampling point and the local pollutants. However, none of the discussed elements, Al, Ce, Fe, Ti, and V, is significantly influenced by the land use. The data allows one to make the conclusion that the elements of Al, Ce, Fe, Ti and V are dependent on the dry and wet deposition on the leaves of T. officinale. These elements are taken up not only by the roots, but also by the surface of the leaves. This is evident because there is no correlation between one of these elements in the leaves and the ion pool of the soil.  相似文献   
13.
The sustainability of deltas worldwide is under threat due to the consequences of global environmental change (including climate change) and human interventions in deltaic landscapes. Understanding these systems is becoming increasingly important to assess threats to and opportunities for long-term sustainable development. Here, we propose a simplified, yet inclusive social–ecological system (SES)-centered risk and vulnerability framework and a list of indicators proven to be useful in past delta assessments. In total, 236 indicators were identified through a structured review of peer-reviewed literature performed for three globally relevant deltas—the Mekong, the Ganges–Brahmaputra–Meghna and the Amazon. These are meant to serve as a preliminary “library” of potential indicators to be used for future vulnerability assessments. Based on the reviewed studies, we identified disparities in the availability of indicators to populate some of the vulnerability domains of the proposed framework, as comprehensive social–ecological assessments were seldom implemented in the past. Even in assessments explicitly aiming to capture both the social and the ecological system, there were many more indicators for social susceptibility and coping/adaptive capacities as compared to those relevant for characterizing ecosystem susceptibility or robustness. Moreover, there is a lack of multi-hazard approaches accounting for the specific vulnerability profile of sub-delta areas. We advocate for more comprehensive, truly social–ecological assessments which respond to multi-hazard settings and recognize within-delta differences in vulnerability and risk. Such assessments could make use of the proposed framework and list of indicators as a starting point and amend it with new indicators that would allow capturing the complexity as well as the multi-hazard exposure in a typical delta SES.  相似文献   
14.
Abstract

Average concentrations of particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) in Steubenville, OH, have decreased by more than 10 μg/m3 since the landmark Harvard Six Cities Study1 associated the city’s elevated PM2.5 concentrations with adverse health effects in the 1980s. Given the promulgation of a new National Ambient Air Quality Standard (NAAQS) for PM2.5 in 1997, a current assessment of PM2.5 in the Steubenville region is warranted. The Steubenville Comprehensive Air Monitoring Program (SCAMP) was conducted from 2000 through 2002 to provide such an assessment. The program included both an outdoor ambient air monitoring component and an indoor and personal air sampling component. This paper, which is the first in a series of four that will present results from the outdoor portion of SCAMP, provides an overview of the outdoor ambient air monitoring program and addresses statistical issues, most notably autocorrelation, that have been overlooked by many PM2.5 data analyses. The average PM2.5 concentration measured in Steubenville during SCAMP (18.4 μg/m3) was 3.4g/m3 above the annual PM2.5 NAAQS. On average, sulfate and organic material accounted for ~31% and 25%, respectively, of the total PM2.5 mass. Local sources contributed an estimated 4.6 μg/m3 to Steubenville’s mean PM2.5 concentration. PM2.5 and each of its major ionic components were significantly correlated in space across all pairs of monitoring sites in the region, suggesting the influence of meteorology and long-range transport on regional PM2.5 concentrations. Statistically significant autocorrelation was observed among time series of PM2.5 and component data collected at daily and 1-in-4-day frequencies during SCAMP. Results of spatial analyses that accounted for autocorrelation were generally consistent with findings from previous studies that did not consider autocorrelation; however, these analyses also indicated that failure to account for autocorrelation can lead to incorrect conclusions about statistical significance.  相似文献   
15.
Abstract

In developing countries, high levels of particle pollution from the use of coal and biomass fuels for household cooking and heating are a major cause of ill health and premature mortality. The cost and complexity of existing monitoring equipment, combined with the need to sample many locations, make routine quantification of household particle pollution levels difficult. Recent advances in technology, however, have enabled the development of a small, portable, data-logging particle monitor modified from commercial smoke alarm technology that can meet the needs of surveys in the developing world at reasonable cost. Laboratory comparisons of a prototype particle monitor developed at the University of California at Berkeley (UCB) with gravi-metric filters, a tapered element oscillating microbalance, and a TSI DustTrak to quantify the UCB particle monitor response as a function of both concentration and particle size and to examine sensor response in relation to changes in temperature, relative humidity, and elevation are presented here. UCB particle monitors showed good linearity in response to different concentrations of laboratory-generated oleic acid aerosols with a coarse (mass median diameter, 2.1 µm) and fine (mass median diameter, 0.27–0.42 µm) size distributions (average r2 = 0.997 ± 0.005). The photoelectric and ionization chamber showed a wide range of responses based on particle size and, thus, require calibration with the aerosol of interest. The ionization chamber was five times more sensitive to fine rather than coarse particles, whereas the photoelectric chamber was five times more sensitive to coarse than fine. The ratio of the response between the two sensors has the potential for mass calibration of individual data points based on estimated parameters of the size distribution. The results demonstrate the significant potential of this monitor, which will facilitate the evaluation of interventions (improved fuels, stoves, and ventilation) on indoor air pollution levels and research on the impacts of indoor particle levels on health in developing countries.  相似文献   
16.

A dietary shift towards reduced meat consumption is an efficient strategy for countering biodiversity loss and climate change in regions (developed and transition countries) where consumption is already at a very high level or is rapidly expanding (such as China). Biodiversity is being degraded and lost to a considerable extent, with 70 % of the world’s deforestation a result of stripping in order to grow animal feed. Furthermore, about 14.5 % of the world’s anthropogenic greenhouse gas emissions (GHG) are calculated to be the result of (mainly industrial) livestock farming. The research reviewed here focuses on the feasibility of reducing meat consumption in developed and transition countries, as this would—among other positive effects—reduce the global loss of biodiversity, the need for unsustainable agricultural practices and GHG emissions. This article reviews the barriers, opportunities and steps that need to be taken in order to encourage the consumption of less meat, based on an interdisciplinary and multifactor approach. The evidence is gathered from a systematic meta-analysis of factors (including personal, sociocultural and external factors) that influence individual meat-eating behaviour. The most relevant factors that influence behaviour appear to be emotions and cognitive dissonance (between knowledge, conflicting values and actual behaviour) and sociocultural factors (e.g. social norms or social identity). For different factors and groups of people, different strategies are appropriate. For example, for men and older people deploying the health argument or arguing for flexitarianism (reduced meat consumption) may prove the most promising approaches, while providing emotional messages or promoting new social norms is recommended in order to address barriers such as cognitive dissonance.

  相似文献   
17.
Organic solvents, such as dimethylsulfoxide (DMSO) and methanol are widely used as vehicles to solubilise lipophilic test compounds in toxicity testing. However, the effects of such solvents upon innate detoxification processes in aquatic organisms are poorly understood. This study assessed the effect of solvent exposure upon cytochrome P450 (CYP)-mediated xenobiotic metabolism in Daphnia magna and zebrafish larvae (4 d post fertilisation). Adult D. magna were demonstrated to have a low, but detectable, metabolism of ethoxyresorufin in vivo and this activity was not modulated by pre-exposure to DMSO or methanol (24 h, up to 0.1% and 0.05% v/v, respectively). In contrast, the metabolism of ethoxyresorufin in zebrafish larvae was significantly reduced by both solvents (0.1% and 0.05% v/v, respectively) after 24 h of exposure. In zebrafish, these observed decreases in activity towards ethoxyresorufin were accompanied by decreased expression of a variety of genes coding for drug metabolising enzymes (corresponding to CYP1, CYP2, CYP3 and UDP-glucuronyl transferase [UGT] family enzymes), measured by quantitative PCR. Reduction of gene expression and CYP1 enzyme activities by methanol (0.05% v/v) in zebrafish larvae was partially reversed by co-exposure with Aroclor 1254 (100 μg L−1). Overall this study suggests that relatively low concentrations of organic solvents can impact upon the biotransformation of certain xenobiotics in zebrafish larvae, and that this warrants consideration when assessing compounds for metabolism and toxicity in this species.  相似文献   
18.
The evolution of colony size in social insects is influenced by both extrinsic and colony-intrinsic factors. An important intrinsic trait, per-capita productivity, often declines in larger colonies. This pattern, known as Michener’s paradox, can limit the growth of insect societies. In this study, we first describe this problem, survey its occurrence across different ant species, and present a case study of eight cavity-dwelling ants with very small colony sizes. In these species, colonies might never reach sizes at which per-capita productivity decreases. However, in six out of the eight focal species, per-capita productivity did decline with increasing size, in accordance with other studies on per-capita productivity in ants. Several mechanisms, such as resource availability or nest-site limitation, may explain the decrease in per-capita productivity with increases in colony size in our focal species. In these central-place foragers, the individual foraging mode is expected to lead to an increase in travel time as colonies grow. We suggest that polydomy, the concomitant occupation of several nest sites, could serve as a potential strategy to overcome this limitation. Indeed, for one species, we show that polydomy can help to circumvent the reduction in productivity with increasing colony size, suggesting that limited resource availability causes the observed decrease in per-capita productivity. Finally, we discuss the influence of other factors, such as the nesting ecology and colony homeostasis, on the evolution of colony size in these cavity-dwelling ants.  相似文献   
19.
The holomictic Traunsee is the deepest and second largest lakein Austria. The special characteristic of this ecosystem isthe fact that local salt and soda industries presumably alterthe lake by the discharge of waste materials. Since thebeginning of the 20th century salt and soda works areannually releasing up to 50,000 tons of solid wastes and up to150,000 tons of chloride into Traunsee. To assess potentialeffects of these anthropogenic impacts on the bacterioplanktonthree sampling sites, influenced as well as not influenced bythe industrial discharge, were chosen for comparison andsampled monthly from November 1997 to October 1998. Bacterialabundance ranged between 0.4 to 3.0 × 106 cells ml-1 with decreasing numbers along the depth profile. Theproportion of actively respiring bacteria, i.e. INT [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride]reducing cells, never exceeded 10% of DAPI (4',6'-diamidino-2-phenylindole) stained cells. Fluorescence in situ hybridization (FISH) was used to examine the seasonal and spatial distribution of dominant phylogenetic groups of thebacterioplankton. Up to 84% of bacteria detected with DAPIcould be detected via FISH applying the universal bacterialprobe EUB338. Percentages of alpha- and beta-Proteobacteriaand members of the Cytophaga-Flavobacterium cluster did notexceed 60% of DAPI-stained cells.Beta-Proteobacteriaappeared to be the most abundant group, not only in Traunsee butalso in two reference lakes, Attersee and Hallstättersee. No significant differences in any of the bacterial parameters couldbe detected between the three sampling sites and all measurementswere found in the range reported for oligotrophic lakes. The highdischarge of the Traun River, resulting in a lake water renewaltime of only one year, may diminish possible effects of industrial waste discharge in the pelagic zone.  相似文献   
20.
Traunsee is a deep oligotrophic lake in Austria characterised by an artificial enrichment of chloride in the hypolimnion (up to 170 mg L-1) caused by waste disposal of soda and salt industries. Protists were collected monthly over one year, observed alive and after Quantitative Protargol Staining (ciliates) or via epifluorescence microscopy (heterotrophic flagellates). Three sites within the lake (0–40 m depths) were compared to deeper water layers from 60–160 m depths where chloride concentrations and conductivity were increased. In addition, we observed the protozooplankton of two neighbouring lakes, i.e. reference systems, during one sampling occasion. In Traunsee the abundance of ciliates was low (200–36 600 cells L-1) in contrast to high species diversity (at least 60 different species; HS = 2.6) throughout the year. The main pelagic species in terms of abundance were small oligotrichs and prostomatids like Rimostrombidium brachykinetum/hyalinum, Balanion planctonicum and Urotricha spp. throughout the investigation period. Among free-living heterotrophic flagellates, which occurred at densities of 40–2800 cells mL-1, small morphotypes dominated in the pelagial. No differences at the community level between the three lakes could be observed and pelagic ciliates and flagellates seemed not to be affected by increased chloride concentrations or by enhanced conductivity.  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