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431.
432.
The herbicides atrazine, simazine and terbuthylazine (and the degradation product deethylatrazine) were analysed in two river-to-open-sea transects and two vertical (open-sea) profiles in the southern Baltic off Poland. Samples taken in September 1995 and April 1997 contained total triazine concentrations ranging from 7 to 31 and 4.5 to 13 ng/dm3, respectively. Concentrations of the individual compounds ranged from 0 to 8 ng/dm3. These are generally higher than levels reported, for example, in the North Sea. The largest surface concentrations were found close to the Vistula and Odra river mouths, endorsing river run-off as a primary source of the triazines. Temporal variability can be related to the late-spring and early-summer agricultural applications of the compounds. Variations in ratios between the individual triazines can be explained by usage patterns and differing residence times. Offshore vertical profiles indicate enrichment of the surface layer through atmospheric triazines inputs, highest concentrations above the halocline associated with colloidal organics and lowest concentrations in the bottom waters, probably as a result of particulate scavenging. The influence of the North Sea inflow to the Baltic is also discussed.  相似文献   
433.
Polymict chondritic breccias—rocks composed of fragments originating from different chondritic parent bodies—are of particular interest because they give insights into the mixing of asteroids in the main asteroid belt (occurrence, encounter velocity, transfer time). We describe Northwest Africa (NWA) 5764, a brecciated LL6 chondrite that contains a >16 cm3 L4 clast. The L clast was incorporated in the breccia through a nondestructive, low‐velocity impact. Identical cosmic‐ray exposure ages of the L clast and the LL host (36.6 ± 5.8 Myr), suggest a short transfer time of the L meteoroid to the LL parent body of 0.1 ± 8.1 Myr, if that meteoroid was no larger than a few meters. NWA 5764 (together with St. Mesmin, Dimmitt, and Glanerbrug) shows that effective mixing is possible between ordinary chondrite parent bodies. In NWA 5764 this mixing occurred after the peak of thermal metamorphism on the LL parent body, i.e., at least several tens of Myr after the formation of the solar system. The U,Th‐He ages of the L clast and LL host, identical at about 2.9 Ga, might date the final assembly of the breccia, indicating relatively young mixing in the main asteroid belt as previously evidenced in St. Mesmin.  相似文献   
434.
Fossil iron meteorites are extremely rare in the geological sedimentary record. The paleometeorite described here is the first such finding at the Cretaceous‐Paleogene (K‐Pg) boundary. In the boundary clay from the outcrop at the Lechówka quarry (Poland), fragments of the paleometeorite were found in the bottom part of the host layer. The fragments of meteorite (2–6 mm in size) and meteoritic dust are metallic‐gray in color and have a total weight of 1.8181 g. Geochemical and petrographic analyses of the meteorite from Lechówka reveal the presence of Ni‐rich minerals with a total Ni amount of 2–3 wt%. The identified minerals are taenite, kamacite, schreibersite, Ni‐rich magnetite, and Ni‐rich goethite. No relicts of silicates or chromites were found. The investigated paleometeorite apparently represents an independent fall and does not seem to be derived from the K‐Pg impactor. The high degree of weathering did not permit the chemical classification of the meteorite fragments. However, the recognized mineral inventory, lack of silicates, and their pseudomorphs and texture may indicate that the meteorite remains were an iron meteorite.  相似文献   
435.
Formaldehyde levels were determined in various forms of atmospheric precipitation (rain, snow, road and roof runoff, throughfall) and deposition (rime, hoarfrost, dew) collected over twelve months at various locations in two large urban agglomerations and along two highways. HCHO was found in 303 of 500 samples analyzed, with concentrations ranging from 0.05 to 10.7 mg/dm3. The results confirmed the significant effect of vehicular traffic on formaldehyde levels in various forms of wet deposition. Correlations of formaldehyde levels with other parameters commonly monitored in precipitation and/or deposition were also examined. No correlation was found between HCHO levels and rain volume. On the other hand, positive correlations were found for hydrogen peroxide, non-sea-salt sulphate, nitrate, ammonia, and total organic carbon (TOC). In addition, the effect of selected meteorological parameters (temperature, wind speed, wind direction, rainfall) on the concentration of formaldehyde in various forms of precipitation and runoff (road runoff, roof runoff, throughfall) was studied. The only correlation found was that between HCHO concentration and daily rainfall.  相似文献   
436.
The physical and chemical properties of 8 samples of amber from different localities in Poland (Baltic Coast, Bełchatów Tertiary brown coal, and Jaroszów clay mine) were investigated by N2 sorption at 77 K, positron annihilation spectroscopy for chemical analysis (PASCA) and by organic geochemical methods (FT-IR,1H and13C NMR, GC, and GC-MS). The porosity of the ambers as determined by PASCA consists of narrow micropores with diameters ranging from 0.8 to 0.9 nm and a volume 0.025 cm3 g−1. In the external eroded part of the amber samples (rind) the concentration of pores where positronium atoms can form is lower and consists of approximately12 the concentration as in their interior. Values of pore parameters determined from sorption of N2 are comparable with those found by the PASCA method. The average diameter of pores ranges from 2 to 12 nm, while their volume varies from 0.018 to 0.048 cm3 g−1.. The chemical character of the ambers is similar based on FT-IR spectroscopy. However, noticeable differences in concentrations of ester and hydroxyl groups are observed in both exterior and interior regions, where the abundances of the ester groups are lower in the exterior rind. The proportion of organic material extractable with chloroform-methanol (1:1, v/v) ranges from 15 to 50% and correlates inversely to the average reflectances (Rr) of polished amber surfaces which range from 1.7 to 0.1 %. These variations are attributed to differing concentrations of oxygenated groups in the respective amber samples. The FT-IR spectra of the non-polar fractions (NP) from the extracts resemble the spectra of the source ambers. However, the intensities of the absorbance for the hdroxyl group are much lower, while absorbances for exomethylene groups are not present. The1H and13C NMR data of NP fractions showed a complex diversity of components in mixtures with different relative concentrations but predominantly aliphatic in character for the respective samples.GC and GC-MS analyses of these fractions revealed that they are comprised of a mixture of compounds typical for Baltic amber but with variable relative concentrations. Two groups of compounds are found to be common to all NP fractions. The first is a minor concentration of homologousn-alkanes with a characteristic Gaussian distribution in the range from C22 to C32 and maximizing at C26–C27. In addition C22 is characteristically slightly higher in concentration compared to C23. The second group of compounds is comprised of succinates with methyl, fenchyl, bomyl and isobornyl alcohols. The composition of these diesters revealed the same equilibrium ratio between compounds with fenchyl, bornyl and isobornyl alcohols in all NP fractions. We suggest an early enzymatically controlled (bacterial) process in the formation of succinates during resin diagenesis from the biotic precursors, yielding the same characteristic ratio of the respective succinates in these ambers. These results show that all the ambers analyzed here fall into a common class of fossil resin, succinite (class Ia) independent of the sample location in Poland.  相似文献   
437.
This study employs facies analysis and basic principles of sequence stratigraphy to correlate isolated outcrop sections and reveal the depositional history of the Chmielnik Formation – a prominent mid‐Serravalian clastic wedge formed on the basinward forebulge flank of the Polish Carpathian Foredeep. The coarse‐grained clastic wedge, up to 30 m thick and spanning ca 1·1 Ma within biozone NN6, consists of fluvio‐deltaic, foreshore and shoreface deposits with a range of large littoral sand bars, all enveloped in muddy offshore‐transition deposits. Its dynamic stratigraphy indicates rapid shoreline shifts and environmental changes due to the interplay of forebulge tectonism, sediment supply and third‐order eustatic cycles. A similar interplay of tectonism and eustasy is recognizable in the whole middle Miocene sedimentary succession deposited on the forebulge flank, demonstrating an extreme case of an accommodation‐controlled shelf and indicating tectonic cycles of the forebulge uplift and subsidence spanning ca 800 to 900 ka. The episodes of forebulge uplift correlate with the main pulses of orogen thrusting. The resulting composite peripheral unconformity differs markedly from the idealized model of a ‘steady‐state’ stepwise onlap driven by forebulge continuous retreat. It is concluded that the foredeep peripheral unconformities, instead of being simplified in accordance with this idealized model, should rather be studied in detail because they bear a valuable high‐resolution record of regional events and give unique insights into the local role of tectonics, eustasy and sediment supply.  相似文献   
438.
Thermal treatment of waste from the meat industry in high scale rotary kiln   总被引:1,自引:0,他引:1  
Recently there has been an increase in consumption of meat, especially poultry. This results in an increase in the quantity of waste, including waste feathers. Waste from the meat industry are hazardous, which must be disposed of in accordance with the law. Wastes from the meat industry normally consist of valuable elements such as phosphorus, calcium, potassium, magnesium (macronutrients), and iron, copper, zinc, manganese (micronutrients), which after suitable processing can be used for the purposes of fertilization. The paper presents the results of thermal treatment of feathers with meat and bone meal and feathers with poultry litter in a high scale rotary kiln. Mixtures of wastes were incinerated in temperature range from 600 to 900 °C for about 20–25 min. The resulting ashes were characterized by a high content of phosphorus (4–17%), calcium (17–30%) and potassium (0.6–3.6%). The study revealed that the selection of process parameters allows for obtaining ash with controlled and desired composition of macro and micronutrients, moreover, it is safe in terms of sanitary.  相似文献   
439.
In this paper, fluvial deposits of Middle Pleistocene age in the mountain‐foreland area of southern Poland (Eastern Sudetes and Western Carpathians) are studied in order to document the evolution of fluvial systems during the coldest stages of glacial periods when the Scandinavian Ice Sheet advanced far to the south. The focus is on fluvial response to climate change and glacial impact on river system behaviour. Also considered is the tectonic uplift of the mountain part of river catchments and its potential influence on the style of fluvial sedimentation in the fore‐mountain area. Three drainage basins that were active during the Elsterian and Saalian glaciations are investigated. Facies analyses are carried out on thick successions of braided river deposits covered with till or glaciolacustrine sediments, which result in a reconstruction of the fluvial activity synchronous with the ice‐sheet advance. The results suggest that fluvial activity declined prior to ice‐sheet advance into the fore‐mountain area. This climatically induced change is directly recorded in alluvial successions by upward‐decreasing bed thicknesses and grain sizes. River longitudinal profiles were shortened in front of the advancing ice sheet. The base level of the studied rivers, created by the ice‐sheet margin, rose in parallel with glacial advance. As a result, the successive reaches of rivers (degradational, transitional, aggradational) underwent shortening and moved upstream within the catchments. Moreover, tectonically induced local increases of river slopes may have influenced the depositional processes.  相似文献   
440.
Detailed X‐ray compositional mapping and microtomography have revealed the complex zoning and growth history of garnet in a kyanite‐bearing eclogite. The garnet occurs as clusters of coalesced grains with cores revealing slightly higher Ca and lower Mg than the rims forming the coalescence zones between the grains. Core regions of the garnet host inclusions of omphacite with the highest jadeite, and phengite with the highest Si, similar to values in the cores of omphacite and phengite located in the matrix. Therefore, the core compositions of garnet, omphacite, and phengite have been chosen for the peak pressure estimate. Coupled conventional thermobarometry, average P–T, and phase equilibrium modelling in the NCKFMMnASHT system yields P–T conditions of 26–30 kbar at 800–930°C. Although coesite is not preserved, these P–T conditions partially overlap the coesite stability field, suggesting near ultra‐high–pressure (UHP) conditions during the formation of this eclogite. Therefore, the peak pressure assemblage is suggested to have been garnet–omphacite–kyanite–phengite–coesite/quartz–rutile. Additional lines of evidence for the possible UHP origin of the Mi?dzygórze eclogite are the presence of rod‐shaped inclusions of quartz parallel to the c‐axis in omphacite as well as relatively high values of Ca‐Tschermak and Ca‐Eskola components. Late zoisite, rare diopside–plagioclase symplectites rimming omphacite, and minor phlogopite–plagioclase symplectites replacing phengite formed during retrogression together with later amphibole. These retrograde assemblages lack minerals typical of granulite facies, which suggests simultaneous decompression and cooling during exhumation before the crustal‐scale folding that was responsible for final exhumation of the eclogite.  相似文献   
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