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421.
M. Zielińska K. Bułkowska A. Cydzik-Kwiatkowska K. Bernat I. Wojnowska-Baryła 《International Journal of Environmental Science and Technology》2016,13(9):2239-2248
Bisphenol A (BPA) is an endocrine disruptor that is difficult to completely remove from wastewater by conventional biological methods. Increased post-treatment BPA removal with ceramic membranes is worth investigating because of these membranes’ mechanical and chemical stability and lifespan. To determine the effectiveness of ceramic membranes for post-treatment of biologically treated BPA-contaminated wastewater, microfiltration (MF) and nanofiltration (NF) were conducted. Both processes removed BPA completely at an initial BPA concentration of 0.3 ± 0.14 mg/L. Increased concentration of 0.7 ± 0.29 mg/L decreased BPA removal. MF removed at least 24 % of BPA, presumably because BPA was adsorbed on particulate matter, which was retained by the membrane, or adsorbed on its surface. NF removed up to thrice more BPA. MF and NF completely removed suspended solids and 40–60 % COD. Filtration capacity decreased with time due to fouling but did not depend on initial BPA concentration. BPA concentrations in municipal wastewater are typically lower than the lowest concentration tested, where MF completely removed BPA. Hence, MF ceramic membranes appear a promising solution for post-treatment of BPA-containing wastewater. MF can be used at a much lower transmembrane pressure than NF, requiring less energy to pump wastewater through the membrane, thus reducing costs. 相似文献
422.
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424.
Krystyna Szeroczyńska Andrzej Tatur Jan Weckström Michał Gąsiorowski Agnieszka M. Noryśkiewicz Elwira Sienkiewicz 《Journal of Paleolimnology》2007,38(1):25-47
A 2.5-m-long sediment core was retrieved from Lake Somaslampi, a small lake located in a kame field on the north slope of
the Scandes Mountains in Finnish Lapland. Holocene environmental changes were inferred from the lithological, geochemical,
pollen, diatom and Cladocera records stored in the lake sediment. The chronology was based on six radiocarbon AMS dates supported
by a palynological control chronology. The sediment profile consists of a glacial sedimentary sequence truncated by a lacustrine
one. A hiatus, tentatively correlated with climate cooling and advances of glaciers during the 8.2 ka yrs BP “Finse cooling
Event”, occurs between these sequences. The glacial sequence was composed of fluvioglacial clastics, smoothly changing into
glacio-lacustrine diatomaceous ooze deposited in a meromictic proglacial lake that covered the kame field. The meromixis was
probably caused by the greater depth of the lake, the extended ice-cover, and the microbial mats covering large areas of the
lake bottom. A distinct change in the biota of the glacio-lacustrine sediments indicates higher trophic conditions than during
deposition of the fluvioglacial clastics. The late-Pleistocene vegetation was characterised by subarctic birch tundra vegetation
(Betula–Salix–Ericaceae) with low biodiversity gradually changing to Betula–Pinus dominance in the early Holocene. The lake was deep and had a diatom inferred pH ~ 7 indicated also by the dominance of planktonic
Cladocera.
The base of the lacustrine sediment sequence (6,650–6,300 cal. BP) consisted of loess-rich sediment indicating an increase
in eolian activity. This is also supported by the pollen record, which is dominated by more long-distant taxa such as Alnus and Pinus, and by the increased C/N ratio of the sediment. After the initial meromictic phase of the lake, an abrupt lowering of the
water level occurred. Lake Somaslampi was isolated from the larger Pre-Lake Somas basin and became holomictic, shallow, much
warmer and more productive, until the deterioration of climate around 3,000 yr BP and the increased input of clastics from
the tundra soils. The vegetation followed the general climatic trend by gradually changing from the dominance of Betula and Pinus to the dominance of more tundra-related vegetation like Poaceae and Cyperaceae. However, the higher frequencies of planktonic
Cladocera and centric diatoms in the most recent sediments indicates higher trophic conditions, increased turbulence and a
prolonged ice-free period, which can possibly be linked to the recent climate warming especially in areas of higher altitude
and latitude. 相似文献
425.
Bogusław M. Domański 《Acta Geophysica》2007,55(3):267-287
An analysis of source parameters of the two unexpected earthquakes from the Kaliningrad (Russia) area is presented. The earthquakes
occurred on 21 September 2004 at 11:05:01 and 13:32:31 UT, respectively. The first event was located at the latitude φ = 54.924°N and the longitude λ = 20.120°E, with a depth h = 16 km, and the second event at φ = 54.876°N, λ = 20.120°E and h = 20 km.
Magnitudes Mw of the two events were very similar: 5.1 and 5.2. The magnitude values reported by various international data centers have
been meaningfully different. The reason is the presence of high-frequency components in Z velocity component of the S wavefield.
They were observed along the direction defined by two stations, BLEU in Sweden and SUW in Poland, located in opposite sides
of the source. Along the direction perpendicular to it, the effects are relatively very small. The high-frequency waves are
understood to mean components in the 6–8 Hz band for event 1 and 2-4 Hz for event 2. The effects in question are also clearly
visible on displacement spectrograms. The magnitude values calculated at such stations from S-wave amplitudes or from seismic
spectra are clearly overestimated and are close to 6. Therefore, we made a careful selection of channels in order to determine
the spectral parameters and, on this basis, the source parameters.
The size of the source is relatively small, of about 2 km. The closest seismic station is at 100 source radii from the source.
One can clearly see the effect of the TT zone which markedly reduces the seismic moment value for seismic stations laying
on the opposite sides of the source. Both events have very similar spatial distributions of the source parameters: magnitude,
seismic moment and radius. 相似文献
426.
Anomalous behaviour of plasma parameters as observed by the intercosmos 24 satellite prior to the iranian earthquake of 20 June 1990 总被引:2,自引:0,他引:2
Summary Measurements of plasma parameters were made by the Intercosmos 24 satellite at altitudes between 2300 km and 2500 km in the
interval of 16 to 12 hours prior to the initial shock of the destructive Iranian earthquake of 20 June 1990 (210009 UT, 37°
N, 49·4° E, M=6·4), and before the strong aftershock of 21 June 1990 (090214 UT, M=5·8). The anomalous behaviour of the light
ionospheric ions H+ and He+ and the cold electron temperature was observed over a wide region of the Northern Hemisphere before the earthquake. Sudden
increases of energetic electron fluxes were observed over the Asian zone near the epicentre. These changes appear to be a
part of the solid Earth — near space interaction occurring during the preparatory stage of the great seismic event. 相似文献
427.
Patricia Roeser Nadine Dräger Dariusz Brykała Florian Ott Sylvia Pinkerneil Piotr Gierszewski Christin Lindemann Birgit Plessen Brian Brademann Michał Kaszubski Michał Fojutowski Markus J. Schwab Michał Słowiński Mirosław Błaszkiewicz Achim Brauer 《Boreas: An International Journal of Quaternary Research》2021,50(2):419-440
We revise the conceptual model of calcite varves and present, for the first time, a dual lake monitoring study in two alkaline lakes providing new insights into the seasonal sedimentation processes forming these varves. The study lakes, Tiefer See in NE Germany and Czechowskie in N Poland, have distinct morphology and bathymetry, and therefore, they are ideal to decipher local effects on seasonal deposition. The monitoring setup in both lakes is largely identical and includes instrumental observation of (i) meteorological parameters, (ii) chemical profiling of the lake water column including water sampling, and (iii) sediment trapping at both bi-weekly and monthly intervals. We then compare our monitoring data with varve micro-facies in the sediment record. One main finding is that calcite varves form complex laminae triplets rather than simple couplets as commonly thought. Sedimentation of varve sub-layers in both lakes is largely dependent on the lake mixing dynamics and results from the same seasonality, commencing with diatom blooms in spring turning into a pulse of calcite precipitation in summer and terminating with a re-suspension layer in autumn and winter, composed of calcite patches, plant fragments and benthic diatoms. Despite the common seasonal cycle, the share of each of these depositional phases in the total annual sediment yield is different between the lakes. In Lake Tiefer See calcite sedimentation has the highest yields, whereas in Lake Czechowskie, the so far underestimated re-suspension sub-layer dominates the sediment accumulation. Even in undisturbed varved sediments, re-suspended material becomes integrated in the sediment fabric and makes up an important share of calcite varves. Thus, while the biogeochemical lake cycle defines the varves’ autochthonous components and micro-facies, the physical setting plays an important role in determining the varve sub-layers’ proportion. 相似文献
428.
429.
M. Cieślak H. Schmidt K. Twarowska-Schmidt I. Kamińska 《International Journal of Environmental Science and Technology》2017,14(7):1371-1382
Textile materials, because of their specific character, can affect the content of volatile pollutants in the indoor air, including the constituents of tobacco smoke (ETS—environmental tobacco smoke). Polypropylene fibers have a particularly high susceptibility for the sorption of nicotine. Textiles made of polypropylene are often used in different rooms or offices. The aim of the research was to give polypropylene fibers the photocatalytic properties by modifying their surface, using titanium dioxide doped with nanoparticles of silver (TiO2/Ag). Modification of polypropylene fibers with TiO2/Ag increases their susceptibility to sorption of nicotine and accelerates its decomposition. A comparison of the decomposition rate constants for the modified and unmodified fibers shows that the decomposition process runs from 1.6 to 2.9 times faster for the modified fibers depending on the nature of modification, the source of the nicotine and the ambient conditions. It was also found that the strength of modified fibers does not change under irradiation. 相似文献
430.
A mathematical model that produces curves for predicting the expansion of granular activated carbon (GAC) filter beds has been developed and applied to several widely used commercial GAC products. Initially, the hydraulic load required to produce a given bed expansion was assumed to be inversely proportional to the viscosity. This assumption was then modified by assuming a power law for the dependence on viscosity. The errors were sufficiently small to allow practical application of the formulae presented in this paper. The potential for application of the method was tested and is illustrated by an example. 相似文献