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181.
The overall measurement of farm level greenhouse gas (GHG) emissions in dairy production is not feasible, from either an engineering or administrative point of view. Instead, computational model systems are used to generate emission inventories, demanding a validation by measurement data. This paper tests the GHG calculation of the dairy farm-level optimization model DAIRYDYN, including methane (CH4) from enteric fermentation and managed manure. The model involves four emission calculation procedures (indicators), differing in the aggregation level of relevant input variables. The corresponding emission factors used by the indicators range from default per cow (activity level) emissions up to emission factors based on feed intake, manure amount, and milk production intensity. For validation of the CH4 accounting of the model, 1-year CH4 measurements of an experimental free-stall dairy farm in Germany are compared to model simulation results. An advantage of this interdisciplinary study is given by the correspondence of the model parameterization and simulation horizon with the experimental farm’s characteristics and measurement period. The results clarify that modeled emission inventories (2,898, 4,637, 4,247, and 3,600 kg CO2-eq. cow?1 year?1) lead to more or less good approximations of online measurements (average 3,845 kg CO2-eq. cow?1 year?1 (±275 owing to manure management)) depending on the indicator utilized. The more farm-specific characteristics are used by the GHG indicator; the lower is the bias of the modeled emissions. Results underline that an accurate emission calculation procedure should capture differences in energy intake, owing to milk production intensity as well as manure storage time. Despite the differences between indicator estimates, the deviation of modeled GHGs using detailed indicators in DAIRYDYN from on-farm measurements is relatively low (between ?6.4 % and 10.5 %), compared with findings from the literature.  相似文献   
182.
Biomarkers and low-molecular weight polyaromatic compounds have been extensively studied for their fate in the environment. They are used for oil spill source identification and monitoring of weathering and degradation processes. However, in some cases, the absence or presence of very low concentration of such components restricts the access of information to spill source. Here we followed the resistance of high-molecular weight sulfur-containing aromatics to the simulated weathering condition of North Sea crude oil by ultra high-resolution Fourier transform ion cyclotron resonance mass spectrometry. The sulfur aromatics in North Sea crude having double bond equivalents (DBE) from 6 to 14 with a mass range 188-674 Da were less influenced even after 6 months artificial weathering. Moreover, the ratio of dibenzothiophenes (DBE 9)/naphthenodibenzothiophenes (DBE 10) was 1.30 and 1.36 in crude oil and 6 months weathered sample, respectively reflecting its weathering stability. It also showed some differences within other oils. Hence, this ratio can be used as a marker of the studied crude and accordingly may be applied for spilled oil source identification in such instances where the light components have already been lost due to environmental influences.  相似文献   
183.
This paper reviews scientific and gray literature addressing climate change vulnerability and adaptation in the Inuvialuit Settlement Region (ISR) in the western Canadian Arctic. The review is structured using a vulnerability framework, and 420 documents related directly or indirectly to climate change are analyzed to provide insights on the current state of knowledge on climate change vulnerability in the ISR as a basis for supporting future research and long-term adaptation planning in the region. The literature documents evidence of climate change in the ISR which is compromising food security and health status, limiting transportation access and travel routes to hunting grounds, and damaging municipal infrastructure. Adaptations are being employed to manage changing conditions; however, many of the adaptations being undertaken are short term, ad-hoc, and reactive in nature. Limited long-term strategic planning for climate change is being undertaken. Current climate change risks are expected to continue in the future with further implications for communities but less is known about the adaptive capacity of communities. This review identifies the importance of targeted vulnerability research that works closely with community members and decision makers to understand the interactions between current and projected climate change and the factors which condition vulnerability and influence adaptation. Research gaps are identified, and recommendations for advancing adaptation planning are outlined.  相似文献   
184.
185.
The CO2SINK pilot project at Ketzin is aimed at a better understanding of geological CO2 storage operation in a saline aquifer. The reservoir consists of fluvial deposits with average permeability ranging between 50 and 100 mDarcy. The main focus of CO2SINK is developing and testing of monitoring and verification technologies. All wells, one for injection and two for observation, are equipped with smart casings (sensors behind casing, facing the rocks) containing a Distributed Temperature Sensing (DTS) and electrodes for Electrical Resistivity Tomography (ERT). The in-hole Gas Membrane Sensors (GMS) observed the arrival of tracers and CO2 with high temporal resolution. Geophysical monitoring includes Moving Source Profiling (MSP), Vertical Seismic Profiling (VSP), crosshole, star and 4-D seismic experiments. Numerical models are benchmarked via the monitoring results indicating a sufficient match between observation and prediction, at least for the arrival of CO2 at the first observation well. Downhole samples of brine showed changes in the fluid composition and biocenosis. First monitoring results indicate anisotropic flow of CO2 coinciding with the “on-time” arrival of CO2 at observation well one (Ktzi 200) and the later arrival at observation well two (Ktzi 202). A risk assessment was performed prior to the start of injection. After one year of operations about 18,000 t of CO2 were injected safely.  相似文献   
186.

Objective  

In this paper, results regarding the leaching of trace elements out of mineral building materials under irrigation are presented.  相似文献   
187.
The potential of triclosan (TCS) acting as an endocrine disruptor has led to growing concern about the presence of TCS in the environment. In this study, seawater samples were collected from the German Bight during sampling campaigns conducted with the German research ships Gauss and Ludwig Prandtl. TCS was determined both in the dissolved phase and in the suspended particulate matters with concentrations ranging 0.8-6870 pg L−1 and <1-95 pg L−1, respectively. High concentrations of TCS were present in the estuaries of the Elbe and the Weser, indicating significant input of TCS by the river discharge. The correlation coefficient (R2) between the dissolved concentration and salinity was 0.79 for the data obtained from the Gauss cruise, showing an obvious declining trend from the coast to the open sea.  相似文献   
188.
Monitoring of immission of persistent organic pollutants in the industrialized area of Volta Redonda (V.R.) and in the National Park of Itatiaia (PNI) in southeast Brazil was performed using an endemic Bromeliad species as biomonitor and measuring total deposition rates on funnels covered with polyurethane foams. Samples were collected during 78 days in V.R. and 95 days in PNI in winter (dry season, June-August 2003) and during 114 days in both areas in summer (rainy season, December 2003-February 2004). The PCDD/PCDF deposition rates ranged from 0.10 to 1.9 pg WHO-TEQ/(m2 day) in winter and from 0.11 to 2.2 pg WHO-TEQ/(m2 day) in summer. Deposition rates found in V.R. in summer were four- to ninefold higher than those measured in PNI, while in winter deposition rates in both regions were in the same range. Deposition rates in V.R. in summer were about five fold lower than those measured in 1996. PCDD/PCDF levels in biomonitor samples were between 0.95 and 14.6 ng WHO-TEQ/kg d.m. in winter and between 2.2 and 5.2 ng WHO-TEQ/kg d.m. in summer. In winter, concentrations found in V.R. were up to 11 times higher than those found in PNI, while in summer the levels measured in both areas were comparable. The homologue and isomer profiles found in the deposition as well as in the biomonitor samples from V.R. indicate that steel production is the main source of contamination in the region, whereas in PNI, the long range transport of these pollutants is the predominant contamination pathway.  相似文献   
189.
The noble gas radon has a strong affinity to non-aqueous phase-liquids (NAPLs). That property makes it applicable as naturally occurring partitioning tracer for assessing residual NAPL contamination of aquifers. In a NAPL contaminated aquifer, radon dissolved in the groundwater partitions preferably into the NAPL. The magnitude of the resulting radon deficit in the groundwater depends on the NAPL-specific radon partition coefficient and on the NAPL saturation of the pore space. Hence, if the partition coefficient is known, the NAPL saturation is attainable by determination of the radon deficit. After a concise discussion of theoretical aspects regarding radon partitioning into NAPL, related experimental data and results of a field investigation are presented. Aim of the laboratory experiments was the determination of radon partition coefficients of multi-component NAPLs of environmental concern. The on-site activities were carried out in order to confirm the applicability of the "radon method" under field conditions.  相似文献   
190.
Intrauterine dilation of critical fetal aortic stenosis (AS) and pulmonary stenosis or atresia has the potential to change the natural course of these congenital heart defects preventing progression to a single ventricle circulation. This article reviews the world experience in fetal cardiac interventions. In carefully selected cases, fetal cardiac surgery can reverse end-stage heart failure and can provide biventricular outcome postnatally in about two thirds of the cases with successful interventions. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
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