全文获取类型
收费全文 | 606篇 |
免费 | 16篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 31篇 |
环保管理 | 85篇 |
综合类 | 138篇 |
基础理论 | 109篇 |
环境理论 | 1篇 |
污染及防治 | 164篇 |
评价与监测 | 43篇 |
社会与环境 | 26篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 12篇 |
2022年 | 21篇 |
2021年 | 16篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 24篇 |
2016年 | 34篇 |
2015年 | 22篇 |
2014年 | 24篇 |
2013年 | 37篇 |
2012年 | 47篇 |
2011年 | 32篇 |
2010年 | 18篇 |
2009年 | 31篇 |
2008年 | 31篇 |
2007年 | 34篇 |
2006年 | 27篇 |
2005年 | 23篇 |
2004年 | 15篇 |
2003年 | 21篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 10篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1983年 | 3篇 |
1964年 | 2篇 |
1959年 | 2篇 |
1957年 | 2篇 |
1925年 | 2篇 |
1924年 | 2篇 |
1923年 | 2篇 |
1921年 | 3篇 |
1918年 | 2篇 |
1917年 | 1篇 |
1914年 | 1篇 |
排序方式: 共有629条查询结果,搜索用时 453 毫秒
501.
Estimating the extent of intraspecific variation in sensitivity to contaminant exposure is important in order to explain variation in the outcome of toxicity tests and to predict the effects of chemical stress on natural populations of plants and animals. However, only few studies provide evident data concerning intraspecific variation in life-history traits caused by a differential response to chemical stress. In this study, we compared the life-history response of six laboratory strains of the midge Chironomus riparius to cadmium exposure in a full life-cycle assay. In addition, the level of genetic variation in all strains was measured at five variable microsatellite loci. Several significant differences in life-history traits among the strains were observed in controls and cadmium treatments. The extent of variation among strains was largest at moderate cadmium concentration (0.42 mg Cd/kg dw). At increased Cd concentrations all strains showed similar levels of high mortality and reduced reproductive success. All strains exhibited considerable levels of genetic impoverishment compared to field populations. Strains with low genetic variation showed reduced fitness in the controls and were more susceptible to Cd exposure. For instance, no reproductive success in the lowest Cd treatment was observed for the strain with the lowest level of genetic diversity. In contrast, this Cd concentration had no negative effects on life-history traits of more variable strains. These results confirm recent findings, that inbreeding and reduced genetic variation influence the reaction of populations towards environmental stress. In addition, we show that the level of genetic variation and inbreeding directly influences the outcome of toxicity tests and contributes to the lack of reproducibility of test results among laboratories. 相似文献
502.
Donatus Bapentire Angnuureng Rafael Almar Nadia Senechal Bruno Castelle Kwasi Appeaning Addo Vincent Marieu Roshanka Ranasinghe 《Journal of Coastal Conservation》2017,21(3):381-392
The present work investigates cross-shore shoreline migration as well as its alongshore variability (with deformation) on timescales of days to years using 6 years of time-averaged video images. The variability of the shoreline is estimated through empirical statistical methods with comprehensive reference to three scales of variability. At the meso-to macro-tidal barred Biscarrosse beach, shoreline responds in decreasing order at seasonal (winter/summer cycles, 52%), event (storms, 28%) and inter-annual scales. Whereas seasonal evolution is dominated by wave climate modulation, short-term evolution is influenced by tidal range and surf-zone sandbar characteristics. The influence of tide range and sandbars increases when timescale decreases. This is even more the case for the alongshore deformation of the shoreline which is dominated by short-term evolution. An EOF analysis reveals that the first mode of shoreline change time series is associated with cross-shore migration and explains 58% of the shoreline variability. The rest of the modes are associated to deformation which explain 42% of shoreline variability. 相似文献
503.
Bruno Vaz Allan T Williams Carlos Pereira da Silva Ergin Aysen 《Journal of Coastal Conservation》2017,21(1):95-103
Beaches are now the most popular tourist destination and increased demand in the past 40 years has led not only to beach congestion but also to a differentiation between urban (resorts, overcrowded and under huge pressure), to natural (less crowded beaches). This diversity needs to be further explored not only to characterize individual beaches in a precise way, but also to understand the distinctive characteristics responsible for options made by beach users. Some attempts have been made to create a universal beach typology but sparse research has been undertaken. The topic is of extreme importance for beach management, as most studies only take into consideration beach usage type and few consider the surrounding environment (landscape). This paper presents an exploratory work for Portuguese beaches which creates a new classification, according to usage and surrounding environment, based on several variables, measured and weighted. The results scale between zero and five and assess how a beach can be classified along an urban (0) to natural (5) spectrum. Variables studied include population density, number of hotels urban density, car park distance to the beach, etc. A pilot study applied to 100 beaches in the Lisbon Metropolitan Area, found that a densely populated region, can also contain beaches with natural characteristics. 相似文献
504.
Mark W. Fitch Ellen England Bo Zhang 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1288-1297
Abstract A polysulfone microporous membrane module was investigated for control of 1-butanol-contaminated gas streams. A diurnal loading condition, using two different butanol concentrations, was used to simulate startup and stop conditions associated with shift work. The membrane module was also used to remove 1-butanol from air under continuous loading conditions in a bioreactor. The reactors were seeded with a mixed bacterial consortium capable of butanol biodegradation. Biokinetic parameters for butanol utilization were determined for the culture to be a maximum specific utilization rate (k) equal to 4.3 d?1 and a half saturation constant (Ks) equal to 8.9 mg L?1. A biofilter running only with diurnal loading conditions giving a “40-hr workweek” had an average 1-butanol removal rate of 29% (111 ppm, 74 gm?3 hr?1) from a 350-ppm influent at the end of an 8-hr operational day. End-of-day removal varied between 4 and 67% during the operational period. With continuous steady-state operation followed by placement on a diurnal loading schedule and influent butanol concentrations increased to 700 ppm, butanol removal averaged 38% (269 ppm, 145 gm?3 hr?1). Under continuous loading, steady-state conditions, 1-butanol removal from the airstream was greater than 99% (200 ppm, 73 gm?3 hr?1). These results suggest that the bioreactor can be operated on a diurnal schedule or 40-hr week operational schedule without any decline in performance. 相似文献
505.
Management of Large Wood in Streams: An Overview and Proposed Framework for Hazard Evaluation
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ellen Wohl Brian P. Bledsoe Kurt D. Fausch Natalie Kramer Kevin R. Bestgen Michael N. Gooseff 《Journal of the American Water Resources Association》2016,52(2):315-335
Instream and floodplain wood can provide many benefits to river ecosystems, but can also create hazards for inhabitants, infrastructure, property, and recreational users in the river corridor. We propose a decision process for managing large wood, and particularly for assessing the relative benefits and hazards associated with individual wood pieces and with accumulations of wood. This process can be applied at varying levels of effort, from a relatively cursory visual assessment to more detailed numerical modeling. Decisions to retain, remove, or modify wood in a channel or on a floodplain are highly dependent on the specific context: the same piece of wood that might require removal in a highly urbanized setting may provide sufficient benefits to justify retention in a natural area or lower‐risk urban setting. The proposed decision process outlined here can be used by individuals with diverse technical backgrounds and in a range of urban to natural river reaches so that opportunities for wood retention or enhancement are increased. 相似文献
506.
Amanda F. Bontempo Gabriella D. P. Carneiro Fernanda A. R. Guimarães Marcelo R. Dos Reis Daniel V. Silva Bruno H. Rocha 《Journal of environmental science and health. Part. B》2016,51(7):465-468
Carrot (Daucus carota L.) is a vegetable crop that is grown throughout the year across various regions of Brazil in rotation or in succession to other cultures. Herbicide residual effect has emerged as a concern, because of the possibility of carryover. Thus, the objective of this study was to evaluate the effect of tembotrione and atrazine residues – in mixture and isolated – on carrot planted in succession to corn. The experiment was designed in randomized blocks with five replications. Treatments consisted of tembotrione (50.4 g ha?1), tembotrione (100.8 g ha?1), tembotrione + atrazine (50.4 g ha?1+ 2 L ha?1), tembotrione + atrazine (100.8 g ha?1+ 2 L ha?1), and atrazine (2.00 L ha?1) applied eight months before carrot seeding, plus a control treatment with no herbicide application. Investigated variables were shoot dry mass, productivity, and classification of carrot roots. The presence of atrazine and tembotrione decreased dry mass in the area, and only tembotrione reduced total root productivity. Thus, there is a carryover effect to tembotrione application that reduces the dry matter accumulation of shoot and total productivity, and an atrazine + tembotrione (100.8 g ha?1) mixture reduces the total productivity after application of these herbicides to soil. 相似文献
507.
Bruno de S. Guimarães Natiele Kleemann Sergiane S. Caldas Fabiane P. Costa Maria A. K. Silveira Fabio A. Duarte Ednei G. Primel 《Environmental science and pollution research international》2014,21(1):584-592
A Fenton oxidation system employing zero-valent iron (whose source was swarf, a residue of metallurgical industries, in powder form) and hydrogen peroxide for the treatment of an aqueous solution with six pesticides was developed, and the effect of the iron metal content, pH, and hydrogen peroxide concentration was evaluated. The characterization of the aqueous solution resulted in: pH 5.6, 105 mg L?1 of dissolved organic carbon, and 44.6 NTU turbidity. In addition, the characterization of the swarf by FAAS and ICP-MS showed 98.43?±?7.40 % of zero-valent iron. The removal was strongly affected by the content of iron metal, pH, and hydrogen peroxide concentration. The best degradation conditions were 2.0 g swarf, pH 2.0, and 5 mmol L?1 H2O2. At the end of the treatment, the pesticide degradation ranged from 60 to 100 %, leading to 55 % mineralization. Besides, all hydrogen peroxide was consumed and the determination of total dissolved iron resulted in 2 mg L?1. Thus, the advantages of this system are rapid degradation (up to 20 min), high-degradation rates, simple handling, and low cost. Figure
A Fenton oxidation system employing Fe0 (in which the source of Fe0 was swarf, a residue in powder form of metallurgical industries) and H2O2 for the degradation of synthetic wastewater comprising six pesticides was developed, and the effect of the amount of Fe0, pH, and H2O2 concentration was evaluated. 相似文献
508.
Kiyoung Lee Yunhyung Hwang Ellen J. Hahn Hilarie Bratset Heather Robertson Mary Kay Rayens 《Journal of the Air & Waste Management Association (1995)》2013,63(5):624-627
The objective was to determine secondhand smoke (SHS) exposure with and without smoke-free laws in urban and rural communities. The research hypothesis was that SHS exposure in public places could be improved by smoke-free law regardless of urban and rural status. Indoor air quality in hospitality venues was assessed in 53 communities (16 urban and 37 rural) before smoke-free laws; 12 communities passed smoke-free laws during the study period. Real-time measurements of particulate matter with 2.5 µm aerodynamic diameter or smaller (PM2.5) were taken 657 times from 586 distinct venues; about 71 venues had both pre- and post-law measurements. Predictors of log-transformed PM2.5 level were determined using multilevel modeling. With covariates of county-level percent minority population, percent with at least high school education, adult smoking rate, and venue-level smoker density, indoor air quality was associated with smoke-free policy status and venue type and their interaction. The geometric means for restaurants, bars, and other public places in communities without smoke-free policies were 22, 63, and 25 times higher than in those with smoke-free laws, respectively. Indoor air quality was not associated with urban status of venue, and none of the interactions involving urban status were significant. SHS exposure in public places did not differ by urban/rural status. Indoor air quality was associated with smoke-free law status and venue type.Implications:?This study analyzed 657 measurements of indoor PM2.5 level in 53 communities in Kentucky, USA. Although indoor air quality in public places was associated with smoke-free policy status and venue type, it did not differ by urban and rural status. The finding supports the idea that population in rural communities can be protected with smoke-free policy. Therefore, it is critical to implement smoke-free policy in rural communities as well as urban areas. 相似文献
509.
Bruno Spinosa DeMartinis Fernando Mauro Lanças 《Journal of environmental science and health. Part. B》2013,48(5):539-547
Abstract Supercritical fluid extraction (SFE) is a rapid and convenient method for the isolation of organic compounds from environmental samples. This paper describes a supercritical carbon dioxide (CO2) extraction system that uses a newly designed extraction cell to recover organic compounds from an aqueous matrix. Analysis of the extracts by gas chromatography‐electron capture detector (GC‐ECD) indicated that the herbicide trifluralin (2,6‐dinitro‐N,N‐dipropyl‐4‐trifluoromethylaniline) could be quantitatively extracted by using the SFE system proposed with small amounts of sample. The percentage of recovery obtained with the SFE system described was twice as high as the result obtained using a conventional solid‐phase extraction technique. Extraction by SFE was completed in a short period of time using a simple and low‐cost home‐made system that did not require the use of organic solvents. 相似文献
510.
Meta-analysis of environmental contamination by phthalates 总被引:1,自引:0,他引:1
Alexandre Bergé Mathieu Cladière Johnny Gasperi Annie Coursimault Bruno Tassin Régis Moilleron 《Environmental science and pollution research international》2013,20(11):8057-8076
Phthalate acid esters (PAE), commonly named phthalates, are toxics classified as endocrine-disrupting compounds; they are primarily used as additives to improve the flexibility in polyvinyl chloride. Many studies have reported the occurrence of phthalates in different environmental matrices; however, none of these studies has yet established a complete overview for those compounds in the water cycle within an urban environment. This review summarizes PAE concentrations for all environmental media throughout the water cycle, from atmosphere to receiving waters. Once the occurrences of compounds have been evaluated for each environmental compartment (urban wastewater, wastewater treatment plants, atmosphere, and the natural environment), we reviewed data in order to identify the fate of PAE in the environment and establish whether geographical and historical trends exist. Indeed, geographical and historical trends appear between Europe and other countries such as USA/Canada and China, however they remain location dependent. This study aimed at identifying both the correlations existing between environmental compartments and the processes influencing the fate and transport of these contaminants into the environment. In Europe, the concentrations measured in waterways today represent the background level of contamination, which provides evidence of a past diffuse pollution. In contrast, an increasing trend has actually been observed for developing countries, especially for China. 相似文献