全文获取类型
收费全文 | 5428篇 |
免费 | 49篇 |
国内免费 | 29篇 |
专业分类
安全科学 | 119篇 |
废物处理 | 264篇 |
环保管理 | 389篇 |
综合类 | 878篇 |
基础理论 | 1335篇 |
环境理论 | 5篇 |
污染及防治 | 1774篇 |
评价与监测 | 428篇 |
社会与环境 | 297篇 |
灾害及防治 | 17篇 |
出版年
2023年 | 61篇 |
2022年 | 139篇 |
2021年 | 155篇 |
2020年 | 76篇 |
2019年 | 87篇 |
2018年 | 194篇 |
2017年 | 214篇 |
2016年 | 282篇 |
2015年 | 186篇 |
2014年 | 287篇 |
2013年 | 429篇 |
2012年 | 316篇 |
2011年 | 352篇 |
2010年 | 239篇 |
2009年 | 194篇 |
2008年 | 329篇 |
2007年 | 300篇 |
2006年 | 246篇 |
2005年 | 195篇 |
2004年 | 176篇 |
2003年 | 150篇 |
2002年 | 123篇 |
2001年 | 84篇 |
2000年 | 43篇 |
1999年 | 50篇 |
1998年 | 27篇 |
1997年 | 21篇 |
1996年 | 22篇 |
1995年 | 33篇 |
1994年 | 30篇 |
1993年 | 10篇 |
1992年 | 21篇 |
1991年 | 22篇 |
1990年 | 23篇 |
1989年 | 16篇 |
1988年 | 15篇 |
1987年 | 11篇 |
1986年 | 25篇 |
1985年 | 13篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 19篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1972年 | 10篇 |
1966年 | 16篇 |
1965年 | 10篇 |
1957年 | 9篇 |
1956年 | 12篇 |
1954年 | 10篇 |
排序方式: 共有5506条查询结果,搜索用时 140 毫秒
181.
Oscar Pindado Rosa Ma Pérez Susana García Miguel Sánchez Pilar Galán Marta Fernández 《Atmospheric environment (Oxford, England : 1994)》2009,43(17):2796-2803
The results from a year-long study of the organic composition of PM2.5 aerosol collected in a rural area influenced by a highway of Spain are reported. The lack of prior information related to the organic composition of PM2.5 aerosol in Spain, concretely in rural areas, led definition of the goals of this study. As a result, this work has been able to characterize the main organic components of atmospheric aerosols, including several compounds of SOA, and has conducted a multivariate analysis in order to assign sources of particulate matter. A total of 89 samples were taken between April 2004 and April 2005 using a high-volume sampler. Features and abundance of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), alcohols and acids were separately determined using gas chromatography/mass spectrometry and high performance liquid chromatography analysis. The Σn-alkane and ΣPAHs ranged from 3 to 81 ng m?3 and 0.1 to 6 ng m?3 respectively, with higher concentrations during colder months. Ambient concentrations of Σalcohols and Σacids ranged from 21 to 184 ng m?3 and 39 to 733 ng m?3, respectively. Also, several components of secondary organic aerosol have been quantified, confirming the biogenic contribution to ambient aerosol. In addition, factor analysis was used to reveal origin of organic compounds associated to particulate matter. Eight factors were extracted accounting more than 83% of the variability in the original data. These factors were assigned to a typical high pollution episode by anthropogenic particles, crustal material, plant waxes, fossil fuel combustion, temperature, microbiological emissions, SOA and dispersion of pollutants by wind action. Finally, a cluster analysis was used to compare the organic composition between the four seasons. 相似文献
182.
Bustamante J Pacios F Díaz-Delgado R Aragonés D 《Journal of environmental management》2009,90(7):2219-2225
We have used Landsat-5 TM and Landsat-7 ETM+ images together with simultaneous ground-truth data at sample points in the Doñana marshes to predict water turbidity and depth from band reflectance using Generalized Additive Models. We have point samples for 12 different dates simultaneous with 7 Landsat-5 and 5 Landsat-7 overpasses. The best model for water turbidity in the marsh explained 38% of variance in ground-truth data and included as predictors band 3 (630–690 nm), band 5 (1550–1750 nm) and the ratio between bands 1 (450–520 nm) and 4 (760–900 nm). Water turbidity is easier to predict for water bodies like the Guadalquivir River and artificial ponds that are deep and not affected by bottom soil reflectance and aquatic vegetation. For the latter, a simple model using band 3 reflectance explains 78.6% of the variance. Water depth is easier to predict than turbidity. The best model for water depth in the marsh explains 78% of the variance and includes as predictors band 1, band 5, the ratio between band 2 (520–600 nm) and band 4, and bottom soil reflectance in band 4 in September, when the marsh is dry. The water turbidity and water depth models have been developed in order to reconstruct historical changes in Doñana wetlands during the last 30 years using the Landsat satellite images time series. 相似文献
183.
Costa EA Campos VP da Silva Filho LC Greven HA 《Journal of environmental management》2009,90(2):1060-1068
In recent years, growing interest has focused on determining the performance of materials and evaluating the service life of structures exposed to various environmental forces. In this context, the determination of the aggressive potential of marine salts on mortars used as external renders is critical. The present study aimed to evaluate the spatial distribution of marine salts relative to distance from the sea. This was done by monitoring the deposition rate of chlorides and sulfates in wet candle sensors, located at nine stations scattered around the Metropolitan Region of Salvador, state of Bahia, Brazil. The study also determined the effectiveness of water-soluble salts at penetrating three different types of mortars of varying cement content via deposition and diffusion. The methodology employed enabled an evaluation of the efficiency of the monitoring sensors' measurement of the aggressiveness potential of local marine aerosol, and determination of the comparative performance of the three mortars tested, from the standpoint of resistance to salt penetration. The type and amount of salts captured both in solution and in powder samples extracted from the mortars were determined by ion chromatography. The analysis of the various types of mortars tested indicated which types are more resistant to the aggressive potential of the region's marine aerosol and the distance from the shore where local buildings are liable to be most strongly affected. 相似文献
184.
Use of Descriptors of Ecosystem Functioning for Monitoring a National Park Network: A Remote Sensing Approach 总被引:1,自引:0,他引:1
Baseline assessments and monitoring of protected areas are essential for making management decisions, evaluating the effectiveness
of management practices, and tracking the effects of global changes. For these purposes, the analysis of functional attributes
of ecosystems (i.e., different aspects of the exchange of matter and energy) has advantages over the traditional use of structural
attributes, like a quicker response to disturbances and the fact that they are easily monitored through remote sensing. In
this study, we described the spatiotemporal patterns of different aspects of the ecosystem functioning of the Spanish national
parks and their response to environmental changes between 1982 and 2006. To do so, we used the NOAA/AVHRR-GIMMS dataset of
the Normalized Difference Vegetation Index (NDVI), a linear estimator of the fraction of photosynthetic active radiation intercepted
by vegetation, which is the main control of carbon gains. Nearly all parks have significantly changed during the last 25 years:
The radiation interception has increased, the contrast between the growing and nongrowing seasons has diminished, and the
dates of maximum and minimum interception have advanced. Some parks concentrated more changes than others and the degree of
change varied depending on their different environmental conditions, management, and conservation histories. Our approach
identified reference conditions and temporal changes for different aspects of ecosystem functioning, which can be used for
management purposes of protected areas in response to global changes. 相似文献
185.
Jessica Nihlén Fahlquist 《Journal of Agricultural and Environmental Ethics》2009,22(2):109-124
The actions performed by individuals, as consumers and citizens, have aggregate negative consequences for the environment.
The question asked in this paper is to what extent it is reasonable to hold individuals and institutions responsible for environmental
problems. A distinction is made between backward-looking and forward-looking responsibility. Previously, individuals were
not seen as being responsible for environmental problems, but an idea that is now sometimes implicitly or explicitly embraced
in the public debate on environmental problems is that individuals are appropriate targets for blame when they perform actions
that are harmful to the environment. This idea is criticized in this paper. It is argued that instead of blaming individuals
for performing actions that are not environmentally friendly we should ascribe forward-looking responsibility to individuals,
a notion that focuses more on capacity and resources than causation and blameworthiness. Furthermore, it is important to emphasize
that a great share of forward-looking responsibility should also be ascribed to institutional agents, primarily governments
and corporations. The urge to ascribe forward-looking responsibility to institutional agents is motivated by the efficiency
aim of responsibility distributions. Simply put, if responsibility is ascribed to governments and corporations there is a
better chance of creating a society in which the opportunities to act in an environmentally friendly way increase. 相似文献
186.
Francisco Ferreira Hugo Tente Pedro Torres Sérgio Cardoso José M. Palma-Oliveira 《Environmental monitoring and assessment》2000,65(1-2):443-450
The environmental decision-making process is related with the interpretation of data both in spatial and temporal dimensions. This paper presents a methodology that integrates the time-space framework of air quality data to infer the temporal pattern and spatial variability that could be interpreted for environmental decision purposes. Variograms that accommodate time and space lags were used for the analysis and proved to be effective. Its environmental meaning, in particular its relationship with traffic patterns is discussed. Data from air quality monitoring stations located in the central part of Lisbon were used in this study. It describes a strategy to identify the type of vehicles responsible for certain pollutant levels, particularly for nitrogen oxides, and discusses the application of new air quality European legislation to the city of Lisbon, Portugal. 相似文献
187.
Vanderstraeten P Lénelle Y Meurrens A Carati D Brenig L Offer ZY Zaady E 《Environmental monitoring and assessment》2008,146(1-3):33-39
The main objective of our research was to compare the airborne particle micromorphology and chemistry in the Brussels environment during agriculture working periods in the surrounding farming region. We used specific methods and instrumentation that are adapted to the climate peculiarities of the Brussels region, the period of investigations (12 months) and the proposed objectives. For the agricultural works we defined the following six periods: before sowing, sowing, after sowing, before harvest, harvest and after harvest. The results indicate a possible temporal correlation between agricultural work periods and airborne particle concentration, micromorphology and chemistry in the Brabant-Brussels region. For wheat and corn plant-growth periods, the average particle size, defined as the area obtained by a planar projection of the particulate, showed important variations in time. For sugar beet and endive, the average area size variations are less important. The roughness and sphericity parameters for the growth periods of the four different plants also showed significant differences. Many of the larger particulates (> 10 microm) are aggregates of even finer particles coated with many still finer ones. The airborne particle chemistry averages (atomic percentage At%), showed that three constituents (Si, S and Fe) dominate all the samples (except for particles 3-10 microm in size, which contain a relatively large percentage of Al). Applying similar investigation methods to study the correlations between airborne particle dynamics in urban zones and the agriculture working periods in their surrounding regions could be of interest to better understand the complexity of the PM problematic. 相似文献
188.
We propose a stochastic dynamic programming framework to model the management of a multi-stand forest under climate risk (strong
wind occurrence). The preferences of the forest-owner are specified by a non-expected utility in order to separately analyze
intertemporal substitution and risk aversion effects. A numerical method is developed to characterize the optimal forest management
policies and the optimal consumption-saving strategy. The stochastic dynamic programming framework is applied to a non-industrial
private forest-owner located in North-East of France. We show that the optimal decisions both depend upon risk and time preferences.
The authors would like to thank participants at the international conference on Economics of Sustainable Forest Management
in Toronto, at the PARIS 1 seminar on Environmental and Natural Resource Economics, at the 2004 Applied Microeconomics Conference
in Lille and at the 13th annual conference of the European Association of Environmental and Resource Economists at Budapest. 相似文献
189.
Roussel S Reboux G Bellanger AP Sornin S Grenouillet F Dalphin JC Piarroux R Millon L 《Journal of environmental monitoring : JEM》2008,10(6):724-729
Dwellings showing a presence of moulds are considered to be unhealthy both by the inhabitants and by sanitary authorities. Although the thresholds of pathogenicity have not yet been established, the toxic, allergic and infectious risk of indoor moulds is better understood today. A study on indoor fungi contamination for 128 dwellings was done between October and May in France. It concerned 69 dwellings, the occupants of which either complained to the sanitary authorities about problems of moulds and humidity or consulted a doctor who related their symptoms to housing conditions. Fifty-nine other dwellings, the occupants of which were healthy, constituted the control group. We present the statistical analysis of questionnaires, which aimed to clarify characteristics of dwellings associated with high concentrations of airborne moulds. Air samples were taken with an impactor in 500 rooms. On visiting dwellings, investigators obtained answers to 25 questions concerning characteristics of inhabitants and living space, as well as the presence of mould indicators. Indoor and outdoor temperature and indoor relative humidity of air measurements were taken. The total concentration of fungi in the air was significantly higher in ground floor apartments versus those on other floors (p = 0.047), in small and highly occupied dwellings (p = 0.03 and 0.003), in dwellings with electric heating (p = 0.04), without a ventilation system (p = 0.003), with water damage (p = 0.003), and finally, in those where the investigator noted an odour of moisture or visible moulds (p < 0.001). The efficacy of the latter criteria in the evaluation of insalubrity is discussed. 相似文献
190.
Cecilia Lopez y Royo Gérard Pergent Christine Pergent-Martini Gianna Casazza 《Environmental monitoring and assessment》2010,171(1-4):365-380
The seagrass Posidonia oceanica is extensively monitored in Mediterranean coastal waters and is an ideal candidate for an eco-regional assessment of the coastal ecosystem. The aim of this study is to evaluate the potential of P. oceanica as eco-regional indicator for its assessment at the scale of Mediterranean basin. For this purpose, regional and national P. oceanica monitoring programmes are identified, and their data and metadata are collected and compared in terms of objectives, strategies, sampling designs and sampling methods. The analysis identifies a number of issues concerning data quality, reliability and comparability. In particular, the adoption of different sampling designs and methods may introduce relevant errors when comparing data. The results of this study stress the necessity of carefully planning monitoring programmes. Moreover, it highlights that the adoption of a number of common tools would facilitate all Mediterranean monitoring activities and allows an optimisation of management efforts at an eco-regional scale. 相似文献