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281.
Mounting evidence indicates that learning shapes fish foraging and social behavior, which suggests that it may also underlie the frequently reported geographic variation in courtship. In this study, we analyzed how early social experience influences courtship patterns in males of the Amarillo fish (Girardinichthys multiradiatus). In a first experiment, we quantified the courtship of males from two allopatric populations grown in isolation and estimated the heritability of a key attribute of their courtship patterns. Then, we raised males from two allopatric populations with either sympatric or allopatric females and at two different densities, and registered their adult courtship patterns towards females from a third population. We found that the courtship pattern of males has a significant heritable component, yet in the second experiment, it was influenced by what type of females males were raised with, by their social rank (dominant/subordinate/singleton), and by the behavior of the female that they were courting. We conclude that courtship behavior in this fish has a congenital predisposition and is affected during development by different aspects of early experience and seemingly remains flexible throughout life; a complex ontogenetic trajectory that under natural conditions may have led to the locally stable dialect types observed in the courtship patterns of males from allopatric populations.  相似文献   
282.
Genuine Savings (GS) have been much used in recent years as an indicator of a country's sustainability. According to some theorists (e.g. Arrow et al., 2012), under certain conditions a country with a positive level of GS should experience non-declining future utility, given the assumption of unlimited substitutability among all forms of capital (sometimes called “weak” sustainability). This paper reports the first very long-run tests of GS (also called comprehensive investment or adjusted net savings) as a forward-looking indicator of future well-being. We assemble data for British capital back to 1765, and construct several net investment measures which are used as indicators of two alternative measures of future well-being: consumption per capita and real wages. An allowance for a “value of time” due to exogenous technological progress is included in some GS measures, and we demonstrate the importance of this measure and the choice of discount rate over the very long-run. On the whole, our results do not reject the postulated relationship between GS and future well-being, and show GS can be a forward looking indicator of future well-being for periods of up to 100 years.  相似文献   
283.
Conventional indicators of water use for urban areas account primarily for direct water use. In contrast, our objective here is to employ the water footprint (WF) concept and methodology to include the virtual or indirect water use to assess the production‐side and consumption‐side WF of 65 United States (U.S.) cities. The 65 cities include the largest metropolitan areas and some of the major mid‐sized cities in the U.S. We use metropolitan areas to define our city boundaries as this is the native spatial resolution of the main datasets used. To estimate the urban WFs, we integrated large and disparate datasets, including commodity flow (agricultural, livestock, and industrial commodities), water use, and socioeconomic data. By analyzing the estimated WF values, we found indirect water use accounts on average for 66% of the WF of consumption. We found some cities are net virtual water exporters (11 of 65) because they rely heavily on direct water uses or are heavy producers of industrial commodities. Also, WF patterns vary widely across the U.S. but regional patterns seem to emerge. For example, the dense cities of the U.S. northeast megaregion have a significantly low per capita WF relative to the other cities, while cities in the Gulf Coast megaregion have a significantly higher industrial WF of production and consumption. Furthermore, there is inequality in the WF of consumption where a few cities account for a disproportionate share of the total U.S. urban water uses.  相似文献   
284.
285.
The impact of nanoparticles on fish health is still a matter of debate, since nanotechnology is quite recent. In this study, freshwater benthonic juvenile fish Prochilodus lineatus were exposed through water to three concentrations of TiO2 (0.1, 1, and 10 μg l?1) and ZnO (7, 70, and 700 μg l?1) nanoparticles, as well as to a mixture of both (TiO2 1 μg l?1?+?ZnO 70 μg l?1) for 5 and 30 days. Nanoparticle characterization revealed an increase of aggregate size in the function of concentration, but suspensions were generally stable. Fish mortality was high at subchronic exposure to 70 and 700 μg l?1 of ZnO. Nanoparticle exposure led to decreased acetylcholinesterase activity either in the muscle or in the brain, depending on particle composition (muscle—TiO2 10 μg l?1; brain—ZnO 7 and 700 μg l?1), and protein oxidative damage increased in the brain (ZnO 70 μg l?1) and gills (ZnO 70 μg l?1 and mixture) but not in the liver. Exposed fish had more frequent alterations in the liver (necrosis, vascular congestion, leukocyte infiltration, and basophilic foci) and gills (hyperplasia and epithelial damages, e.g., epithelial disorganization and epithelial loss) than the control fish. Thus, predicted concentrations of TiO2 and ZnO nanoparticles caused detectable effects on P. lineatus that may have important consequences to fish health. But, these effects are much more subtle than those usually reported in the scientific literature for high concentrations or doses of metal nanoparticles.  相似文献   
286.
We aimed to understand relationships of the weather as biometeorological and hospital admissions due to diseases of arteries and veins by subtypes, which have been scarcely studied, in a national setting in recent years. This is an ecological study. Ten percent of daily hospital admissions from the included hospitals (n?=?1,618) across Germany that were available between 1 January 2009 and 31 December 2011 (n?=?5,235,600) were extracted from Statistisches Bundesamt, Germany. We identified I70-I79 Diseases of arteries, arterioles and capillaries and I80-I89 Diseases of veins, lymphatic vessels and lymph nodes by International Classification of Diseases version 10 as the study outcomes. Daily weather data from 64 weather stations that covered 13 German states including air temperature, humidity, wind speed, cloud cover, radiation flux and vapour pressure were obtained and generated into physiologically equivalent temperature (PET). Two-way fractional-polynomial prediction was plotted with 95 % confidence intervals. For most of the subtypes from diseases of arteries and veins, hospital admissions slightly peaked in spring and dropped when PET was at 10 °C. There were no other large differences across 12 months. Admissions of peripheral vascular diseases, arterial embolism and thrombosis, phlebitis and thrombophlebitis, oesophageal varices and nonspecific lymphadenitis peaked when PET was between 0 and ?10 °C, while others peaked when PET was between 0 and 10 °C. More medical resources could have been needed on days when PETs were at ?10 to 10 °C than on other days. Adaptation to such weather change for health professionals and the general public would seem to be imperative.  相似文献   
287.
The measurement of travel costs in recreational demand modeling has been a contentious issue for many decades. This article explores the use of a number of alternative methods of incorporating time costs in the travel cost modeling process. Travel cost values where the opportunity cost of time is excluded, where it is included as a percentage of the individual's reported wage rate and where it based on an estimated wage from a secondary data source (the European Community Household Panel) are compared and then used in a conditional logit model to estimate the demand for whitewater kayaking in Ireland. We then evaluate the effect of different treatments of the cost of travel time on the welfare impacts of a number of different management scenarios for kayaking rivers in Ireland, and find that statistically significant differences emerge.  相似文献   
288.
ObjectivesTo examine the causes associated with high risk helicopter operations, in particular external load and aerial application flight, and determine the role of crew management in accident mitigation strategies.MethodsData from the US National Transportation Safety Board online database were analyzed. Flight phases and types of rotor strike were added categories extracted from the narrative statements included in the accident reports.Results and recommendationsAerial application and external load accidents are characterized by high numbers of rollovers, rotor strikes and errors during preflight checks. Additional flight or ground crew may assist the pilot in maintaining a visual lookout. The number of accidents can be further reduced with adequate fuel management in which both pilot and ground crew can contribute. Although the ground crew can be both victim and cause of an accident, their supporting role has much to contribute to safety in high risk helicopter operations.  相似文献   
289.
The Poxim River is one of Sergipe State’s major waterways. It supplies water to the State capital, Aracaju, but is threatened by urban and agricultural developments that compromise both the quantity and the quality of the water. This has direct impacts on the daily lives of the region’s population. In this work, a multivariate analytical approach was used to investigate the physical and chemical characteristics of the water in the river basin. Four sampling campaigns were undertaken, in November 2005, and in February, May, and September 2006, at 15 sites distributed along the Poxim. The parameters analyzed were conductivity, turbidity, color, total dissolved solids, dissolved oxygen, alkalinity, hardness, chlorophyll-a, and nutrients (total phosphorus, dissolved orthophosphate, nitrite, nitrate, ammoniacal nitrogen, and total nitrogen). Dissolved oxygen contents were very low in the Poxim-Açu River (1.0–2.8), the Poxim River (1.6–4.6), and the estuarine region (1.7–5.1), due to the dumping of wastes and discharges of domestic and industrial effluents containing organic matter into fluvial and estuarine regions of the Poxim. Factor analysis identified five components that were indicative of the quality of the water, and that explained 81.73 % of the total variance.  相似文献   
290.
Textile industry wastes raise a great concern due to their strong coloration and toxicity. The objective of the present work was to characterize the degradation and mineralization of textile effluents by advanced oxidative processes using either TiO2 or TiO2/H2O2 and to monitor the toxicity of the products formed during 6-h irradiation in relation to that of the in natura effluent. The results demonstrated that the TiO2/H2O2 association was more efficient in the mineralization of textile effluents than TiO2, with high mineralized ion concentrations (NH 4 + , NO 3 ? , and SO 4 2? ) and significantly decreased organic matter ratios (represented by the chemical oxygen demand and total organic carbon). The toxicity of the degradation products after 4-h irradiation to Artemia salina L. was not significant (below 10 %). However, the TiO2/H2O2 association produced more toxicity under irradiation than the TiO2 system, which was attributed to the increased presence of oxidants in the first group. Comparatively, the photogenerated products of both TiO2 and the TiO2/H2O2 association were less toxic than the in natura effluent.  相似文献   
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