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301.
Adaptivity of wayfinding strategies in a multi-building ensemble: The effects of spatial structure, task requirements, and metric information 总被引:1,自引:0,他引:1
Christoph Hlscher Simon J. Büchner Tobias Meilinger Gerhard Strube 《Journal of environmental psychology》2009,29(2):208-219
This study investigates the adaptivity of wayfinding strategies in a real-world setting of a multi-building ensemble. Familiarity with the environment, map usage and verbal vs. visual task instructions were systematically varied. Measures included path choices, wayfinding performance and information usage. Thirty-two participants had to find eight goals in a multi-level building ensemble consisting of two distinctive building parts. It was tested whether the standard wall-mounted floor maps found in the majority of public buildings can help navigation in a complex unknown environment. Unfamiliar users tried to make use of these plans more frequently, but were not able to compensate for spatial knowledge deficits compared to participants familiar with the setting. Two strategies of multi-level wayfinding were compared with respect to a region-based hierarchical planning approach. Strategy selection could be shown to be highly adaptive to spatial properties of the environment as well as characteristics of the task instruction, i.e., spatial precision of target information. Overall, the strategy of moving horizontally into the target building prior to vertical travel was shown to be more effective in this multi-building setting. 相似文献
302.
John H. Borden Ian M. Wilson Regine Gries Leslie J. Chong Harold D. Pierce Jr. Gerhard Gries 《Chemoecology》1998,8(2):69-75
Summary. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis of the Porapak Q-captured volatiles from the
bark of trembling aspen, Populus tremuloides Michx., revealed four compounds that consistently elicited antennal responses by mountain pine beetles (MPBs), Dendroctonus ponderosae Hopkins. One of these, 1-hexanol, disrupted the capture of MPBs in multiple-funnel traps baited with the aggregation pheromones
trans-verbenol and exo-brevicomin and the host kairomone myrcene, a blend of semiochemicals that mediates the secondary attraction response in which
beetles mass attack and kill living pines. The other three EAD-active aspen bark volatiles, benzyl alcohol, benzaldehyde and
nonanal, were inactive alone, but in binary and ternary combinations contributed to a disruptive effect in an additive and
redundant manner when all four aspen bark volatiles were tested in all possible binary and ternary blends. The best ternary
blend and the quarternary blend achieved ≥ 80% disruption. The quarternary blend enhanced the disruptive effect of the antiaggregation
pheromone verbenone in traps, raising the disruptive effect to 98%, and also enhanced the inhibition of attack on attractant-baited
lodgepole pines. This is the first demonstration of specific compounds from the bark of angiosperm trees that disrupt the
secondary attraction response of sympatric coniferophagous bark beetles. The results support the hypothesis that such bark
beetles are adapted to recognize and avoid non-host angiosperm trees by responding to a broad spectrum of volatiles that can
act in various blends with equal effect.
Received 27 October 1997; accepted 20 February 1998. 相似文献
303.
A fixed-volume release of 1,2-DCE, tracked in space and time with a light transmission/image analysis system, provided a data set for the infiltration, redistribution, and immobilisation of a dense non-aqueous phase liquid (DNAPL) in a heterogeneous porous medium. The two-dimensional bench scale flow cell was packed with a spatially correlated, random heterogeneous distribution of six sand types. In order to provide the necessary modelling parameters, detailed constitutive relationships were measured at the local scale for the six sands. These experiments revealed that nonwetting phase (NWP) relative permeability-saturation (k(rN)-S(W)) relationships are strongly correlated to sand type. Trends in the best-fit k(rN)-S(W) parameters reflected a positive correlation between mean grain diameter and the maximum NWP relative permeability, k(rN)(max). Multiphase flow simulations of the bench scale experiment best reproduced the experimental observations, producing excellent matches in both time and space, when the measured, correlated local scale k(rN)-S(W) relationships were employed. 相似文献
304.
Lammel G Klöpffer W Semeena VS Schmidt E Leip A 《Environmental science and pollution research international》2007,14(3):153-165
Background, Aim and Scope Modelling of the fate of environmental chemicals can be done by relatively simple multi-media box models or using complex
atmospheric transport models. It was the aim of this work to compare the results obtained for both types of models using a
small set of non-ionic and non-polar or moderately polar organic chemicals, known to be distributed over long distances.
Materials and Methods Predictions of multimedia exposure models of different types, namely three multimedia mass-balance box models (MBMs), two
in the steady state and one in the non-steady state mode, and one non-steady state multicompartment chemistry-atmospheric
transport model (MCTM), are compared for the first time. The models used are SimpleBox, Chemrange, the MPI-MBM and the MPI-MCTM.
The target parameters addressed are compartmental distributions (i.e. mass fractions in the compartments), overall environmental
residence time (i.e. overall persistence and eventually including other final sinks, such as loss to the deep sea) and a measure
for the long-range transport potential. These are derived for atrazine, benz-[a]-pyrene, DDT, α and γ-hexachlorocyclohexane,
methyl parathion and various modes of substance entry into the model world.
Results and Discussion Compartmental distributions in steady state were compared. Steady state needed 2–10 years to be established in the MCTM. The
highest fraction of the substances in air is predicted by the MCTM. Accordingly, the other models predict longer substance
persistence in most cases. The results suggest that temperature affects the compartmental distribution more in the box models,
while it is only one among many climate factors acting in the transport model. The representation of final sinks in the models,
e.g. burial in the sediment, is key for model-based compartmental distribution and persistence predictions. There is a tendency
of MBMs to overestimate substance sinks in air and to underestimate atmospheric transport velocity as a consequence of the
neglection of the temporal and spatial variabilities of these parameters. Therefore, the long-range transport potential in
air derived from MCTM simulations exceeds the one from Chemrange in most cases and least for substances which undergo slow
degradation in air.
Conclusions and Perspectives MBMs should be improved such as to ascertain that the significance of the atmosphere for the multicompartmental cycling is
not systematically underestimated. Both types of models should be improved such as to cover degradation in air in the particle-bound
state and transport via ocean currents. A detailed understanding of the deviations observed in this work and elsewhere should
be gained and multimedia fate box models could then be ‘tuned in’ to match better the results of comprehensive multicompartmental
transport models.
ESS-Submission Editor: Prof. Dr. Michael Matthies (matthies@uos.de) 相似文献
305.
Amirbahman A Schönenberger R Furrer G Zobrist J 《Journal of contaminant hydrology》2003,64(3-4):169-190
Packed bed laboratory column experiments were performed to simulate the biogeochemical processes resulting from microbially catalyzed oxidation of organic matter. These included aerobic respiration, denitrification, and Mn(IV), Fe(III) and SO(4) reduction processes. The effects of these reactions on the aqueous- and solid-phase geochemistry of the aquifer material were closely examined. The data were used to model the development of alkalinity and pH along the column. To study the independent development of Fe(III)- and SO(4)-reducing environments, two columns were used. One of the columns (column 1) contained small enough concentrations of SO(4) in the influent to render the reduction of this species unimportant to the geochemical processes in the column.The rate of microbially catalyzed reduction of Mn(IV) changed with time as evidenced by the variations in the initial rate of Mn(II) production at the head of the column. The concentration of Mn in both columns was controlled by the solubility of rhodochrosite (MnCO(3(S))).In the column where significant SO(4) reduction took place (column 2), the concentration of dissolved Fe(II) was controlled by the solubility of FeS. In column 1, where SO(4) reduction was not important, maximum dissolved Fe(II) concentrations were controlled by the solubility of siderite (FeCO(3(S))). Comparison of solid-phase and aqueous-phase data suggests that nearly 20% of the produced Fe(II) precipitates as siderite in column 1. The solid-phase analysis also indicates that during the course of experiment, approximately 20% of the total Fe(III) hydroxides and more than 70% of the amorphous Fe(III) hydroxides were reduced by dissimilatory iron reduction.The most important sink for dissolved S(-II) produced by the enzymatic reduction of SO(4) was its direct reaction with solid-phase Fe(III) hydroxides leading initially to the formation of FeS. Compared to this pathway, precipitation as FeS did not constitute an important sink for S(-II) in column 2. In this column, the total reacted S(-II) estimated from the concentration of dissolved sulfur species was in good agreement with the produced Cr(II)-reducible sulfur in the solid phase. Solid-phase analysis of the sulfur species indicated that up to half of the originally produced FeS may have possibly transformed to FeS(2). 相似文献
306.
A coupled atmosphere–ocean general circulation model, ECHAM5-MPIOM, was used to study the multicompartmental cycling and long-range transport of persistent and semivolatile organics. Multiphase systems in air and ocean are covered by submodels for atmospheric aerosols, HAM, and marine biogeochemistry, HAMOCC5, respectively. The model, furthermore, encompasses 2D surface compartments, i.e. top soil, vegetation surfaces and sea-ice. The total environmental fate of γ-hexachlorocyclohexane (γ-HCH, lindane) and dichlorophenyltrichloroethane (DDT) in agriculture were studied.DDT is mostly present in the soils, the water-soluble γ-HCH in soils and ocean. DDT has the longest residence time in almost all compartments. Quasi-steady state with regard to substance accumulation is reached within a few years in air and vegetation surfaces. In seawater the partitioning to suspended and sinking particles contributes to the vertical transport of substances. On the global scale deep water formation is, however, found to be more efficient. Up to 30% of DDT but only less than 0.2% of γ-HCH in seawater are stored in particulate matter.On the time scale studied (1 decade) and on global scale substance transport in the environment is determined by the fast atmospheric circulation. The meridional transport mechanism, for both compounds, is significantly enhanced by multi-hopping. Net meridional transport in the ocean is effective only regionally, mostly by currents along the western boundaries of Africa and the Americas. The total environmental burdens of the substances experience a net northward migration from their source regions, which is more pronounced for DDT than for γ-HCH. Due to the application distribution, however, after 10 years of simulation 21% of the global environmental burden of γ-HCH and 12% of DDT have accumulated in the Arctic. 相似文献
307.
Gerhard Lammel Jana Klánová Roman Prokeš Andreas Stohl 《Environmental pollution (Barking, Essex : 1987)》2009,157(12):3264-3271
On Zugspitze (2670 m a.s.l.), Alps, higher concentrations were observed during a winter than during a summer measurement campaign of PAHs, chlorobenzenes (43.6 vs. 2.0 pg m−3) and DDTs (3.7 vs. 1.2 pg m−3), while hexachlorocyclohexanes and PCBs were found at similar levels. The PCB, HCH and DDT levels are among the lowest ever reported from outside the Arctic. Mostly lower levels were found in samples collected in summer than in winter despite a significant boundary layer air influence, but no such influence on samples collected during the winter campaign. Boundary layer influence was quantified by Lagrangian particle dispersion model retroplume analyses. Photochemical lifetimes corresponding to kOH < 1.5 × 10−12 cm3 molec−1 s−1 are found for p,p′-DDT, kOH < 0.75 × 10−12 cm3 molec−1 s−1 for p,p′-DDE and kOH < 1.0 × 10−12 cm3 molec−1 s−1 for p,p′-DDD. 相似文献
308.
Although various single-concentration measurements of the pharmaceutical diclofenac are available in literature, detailed information on the mass flux in the aquatic environment is often missing. Therefore, the overall load of diclofenac was obtained by recording each concentration in nine effluents of sewage treatment plants (STP) and at three river sites located in the area of the river Main (Germany) over a time period of six weeks.In STP effluents, concentrations of up to 2200 ng/L were obtained. In combination with flow rates and connected population an average specific load per capita and day of 0.28 mg (+/? 0.11 mg) diclofenac reaches the receiving water course. This average specific load per capita is an expressive parameter to assess main diclofenac exposure to the aquatic environment avoiding uncertainties of estimated data commonly used in exposure assessment. Accordingly, predicted environmental concentrations (PEC) of 140 ng/L for a realistic worst case scenario and 2 to 52 ng/L based on water quality modeling were derived. Since concentrations of up to 140 ng/L were observed in surface water, the obtained PEC is in perfect agreement with measured concentrations. Hence, comparing the PEC with published predicted no effect concentrations (PNEC), chronic adverse effects in fish populations may occur. 相似文献
309.
de Vos J Dixon R Vermeulen G Gorst-Allman P Cochran J Rohwer E Focant JF 《Chemosphere》2011,82(9):1230-1239
The disposal and dumping of toxic waste is a matter of growing concern in developing countries, including South Africa. Frequently these countries do not possess access to gas chromatography-high resolution mass spectrometry (GC-HRMS) for the determination of persistent organic pollutants (POPs). This publication describes an alternative approach to the investigation of toxic waste using comprehensive gas chromatography coupled to time of flight mass spectrometry (GC × GC-TOFMS). The technology permits both comprehensive screening of toxic samples for numerous classes of organic pollutants and also quantitative analysis for the individual compounds. This paper describes the use of this technique by analysing samples obtained from a hazardous waste treatment facility in South Africa. After sampling and extraction the samples were analysed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and four dioxin-like non-ortho substituted polychlorinated biphenyls (PCBs). The quantitative values, as well as detection limits, obtained using the GC × GC-TOFMS methodology compares well with those obtained using GC-HRMS; the accepted benchmark technology for this analysis. Although GC × GC-TOFMS is not a target compound analytical technique (as is GC-HRMS), it is possible to obtain information on numerous other classes of organic pollutants present in the samples in one analytical run. This is not possible with GC-HRMS. Several different column combinations have been investigated for handling very complex waste samples and suggestions are presented for the most suitable combination. 相似文献
310.
Mass budgets of hexachlorocyclohexanes (alpha-HCH and gamma-HCH) and a polychlorinated biphenyl (PCB 153) for 1995--2001 were calculated based on model simulations and observations for the North Sea as a whole and the German Bight, a coastal shallow subregion. For the North Sea the air-sea fluxes of the three pollutants were net depositional and dominated by local sources (gamma-HCH and PCB 153) or atmospheric deposition (alpha-HCH). The air-sea fluxes were net volatilizational in the German Bight. Unlike HCH, PCB 153 does not show a downward trend in the North Sea marine environment during the study period. Due to its physicochemical properties it is expected to readily enter the food chains. Model results suggest that during studied period, the North Sea was a sink for PCB 153 and a source of HCHs for the outer world. 相似文献