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991.
The traditional radiocarbon method widely used in archaeology and geology for chronological purposes can also be used in environmental studies. Combustion of fossil fuels like coal, natural gas, petroleum, etc., in industrial and/or heavily urbanized areas, has increased the concentration of carbon dioxide in the atmosphere. The addition of fossil carbon caused changes of carbon isotopic composition, in particular, a definite decrease of 14C concentration in atmospheric CO2 and other carbon reservoirs (ocean and terrestrial biosphere), known as the Suess effect. Tree rings, leaves, as well as other annual growing plants reflected the changes of radiocarbon concentration in the atmosphere due to processes of photosynthesis and assimilation of carbon from the air. By measuring radiocarbon concentration directly in atmospheric CO2 samples and/or biospheric material growing in industrial and/or highly urbanized areas where high emission of dead carbon is expected, it is possible to estimate the total emission of dead CO2. Based on equations of mass balance for CO2 concentration, stable isotopic composition of carbon and radiocarbon concentration it is possible to calculate CO2 con-centration associated with fossil fuel emission into the atmosphere. The procedure use differences between the radiocarbon concentration and stable isotope composition of carbon observed in clean areas and industrial or/and highly urbanized areas.  相似文献   
992.
In river valleys, both human occupation and subsequent preservation of archaeological sites are affected by active landscape transformation caused by river lateral migration, incision/aggradation cycles and changes of river hydrological regime. In the middle Vychegda River valley (Northern Russia), there are numerous traces of human presence since the Mesolithic. We exploit multi-disciplinary archaeological, geomorphological and geochronological approach to elucidate the environmental preferences of settlements positioning during different epochs of the Holocene. High resolution space image supplemented with data on alluvial stratigraphy derived from bank exposures and hand cores, as well as 51 radiocarbon dates were used to make the geomorphic map showing ages of floodplain/terrace segments and palaeochannels. Using this map together with sediment facial interpretation, position of archaeological sites was analysed in the context of local geomorphic and hydrologic situation. The majority of archaeological sites and modern settlements are found on terraces at river banks or at oxbow lakes which were well connected to the river. Few exceptions from this rule may be explained by seasonal character of dwelling functioning, ritual burial practice or specialization of settlements. Geomorphic situation was used as a background for planning further prospection of different-age archaeological objects.  相似文献   
993.
A new measurement protocol has been tested on K-feldspars from Whanganui Inlet and Parengarenga Harbour, New Zealand. A Single Aliquot Regenerative (SAR) dose protocol, using two successive infrared (IR) stimulations (post-IR IR SAR protocol) is setup for these young (<1000 years) coastal sediments. Significant anomalous fading (g 2days =7 %/decade) is observed using the conventional IR signal measured at 50°C. In contrast, the fading rate of the IR signal measured at elevated temperature (150°C) after the IR stimulation at 50°C (a post-IR IR signal) is not significant (g 2days ≤ 1 %/decade). Surprisingly low residual infrared stimulated luminescence (IRSL) signals were observed for a surface sample, suggesting that accurate ages as young as ∼50 years can be obtained for these recent deposits. IRSL ages ranging between 48±6 years and 1050±50 years are obtained from six samples, indicating that sediment accumulation has occurred at the two sites during the last millennia, despite a falling trend in relative sea-level in Whanganui Inlet and a stable relative sea-level at Parengarenga Harbour.  相似文献   
994.
In luminescence dating of sediments, Mayya et al. (2006) pointed out that at single grain level, the beta dose for quartz grains is heterogeneous. This heterogeneity arises due the fact that the total potassium in sediment is contributed by few feldspar grains with up to 11–14% stoichiometric potassium (Huntley and Baril, 1997). Beta particles have a range of ∼2 mm, which is comparable to grain sizes and inter-grain distances. This fact implies that the spatial fluctuation of beta emitters (K-feldspars) around individual quartz grains results in heterogeneous dose deposition. These fluctuations therefore, lead to an inherent spread in palaeodoses received by individual quartz grains.  相似文献   
995.
Using a set of modern/young (0 to about 200 years old) dust samples collected from the Chinese Loess Plateau the bleachability of IRSL measured at 50°C (IR50) and post-IR50 elevated temperature IRSL (measured at 225°C and at 290°C) is investigated by measuring the apparent (residual) doses recorded by these signals. Doses recorded by quartz OSL are used as a reference. Allowing for differences in dose rates it seems that both IRSL and post-IR IRSL signals yield residual doses that are significantly larger than the doses measured in quartz. These residual doses can be largely explained by thermal transfer caused by preheating. Nevertheless, we advise against the use of a low temperature preheat (<200°C) with IR50 to date loess samples because, as has been reported before, the signal appears to be thermally unstable. In general, we conclude that it may not be advisable to apply post-IR IRSL dating to Chinese loess samples where residuals of up to ∼20 Gy are a significant fraction of the total dose. However, these residuals quickly become unimportant when dating older samples, and this is the age range in which post-IR IRSL dating is likely to be most useful.  相似文献   
996.
The estimation of firing temperature of ceramics using methods based on pre-dose sensitization of the 110°C TL peak of quartz have yielded incoherent results. Recently the fast component of the CW-OSL of quartz has been observed to have pre-dose characteristics similar to that of the 110°C TL peak. The motivation for this study has been to look into the feasibility of this signal, the OSL counter part of pre-dosed TL emission, for the firing temperature identification. The variation in the sensitization ratio of the TL and OSL emissions with different heating temperatures was also utilized to unveil the firing temperature mark of the specimen.  相似文献   
997.
This study provides a preliminary systematic characterisation of OSL sensitivity, with respect to sediment history, of single grains of Australian quartz from a variety of source rocks and depositional contexts. Samples from two distinct lithologies and with relatively short modern sedimentary histories were compared in an examination of the influence of rock type on OSL sensitivity. Sediments derived from weathered sandstone were found to be brighter than those from metamorphosed schists, suggesting that sensitivity may be inherited from the source rock and its earlier sedimentary history. Secondly, quartz from the same source, but different modes of deposition, was compared to assess the effect on sensitivity of nature of exposure to light during the most recent bleaching event. Quartz grain sensitivity appears not to vary depending on the mode of sediment deposition, suggesting that the nature of exposure to light during deposition is less important in the sensitisation process. This study highlights the complexity and variety of natural sedimentary quartz, demonstrating the limitations of an investigation based solely on OSL sensitivity. Further systematic investigation into the physical, geological and geomorphological characteristics of sediments is proposed to better understand the mechanisms of luminescence sensitisation in quartz.  相似文献   
998.
We present a zooarchaeological analysis of the faunal remains at Tel Beth‐Shemesh, a site located in the Shephelah region of Israel, which has been dated to the Late Bronze Age and Iron Age I. The site, identified as the biblical city of Beth‐Shemesh, was a Canaanite border town between Philistine and Israelite settlements and of great importance in our attempts to understand the social and cultural transformations that occurred in the southern Levant during those periods. This study contributes to a more accurate understanding of the cultural identity of the site's inhabitants by exploring the cultural differences between populations as reflected in their different dietary preferences. We analysed the subsistence economy at the site, the general exploitation patterns, herd management strategies and consumption practices, all of which are based mostly on domestic livestock. We determined the cultural identity at the site mainly by comparing the representation of pig remains with that found at other sites in the region, and offer various explanations for the differences. The comparisons revealed clear differences between Tel Beth‐Shemesh and other known nearby Philistine sites. This site appears to have possessed a self‐contained production and consumption economy with similarities in the general pattern of animal exploitation between the two periods. These similarities constitute evidence for the continuation of the local population and of its culture at the site during the period of turmoil that swept the region during the transition to the Iron Age. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
999.
The ideal indicator of domestic individuals is the presence of traits that must appear in the first generation of the domestic lineage. Most wild geese are migratory, breeding in the subarctic zone and wintering in the temperate zone. If goose remains from archaeological sites in a non‐breeding region are from individuals shown to have died during the breeding season, the bones are likely to be from domestic birds. Medullary bone is secondary woven bony tissue formed in the marrow cavity of breeding female birds. It develops 1 or 2 weeks before the first egg is produced and disappears 1 or 2 weeks after egg production. As wild geese remain in their breeding regions for about 3 months after egg production, medullary bone would be expected to disappear before birds arrive at the stopover and wintering areas. Therefore, the presence of medullary bone in goose remains found in non‐breeding regions would be a reliable indicator of domestic birds. In this study, we examined goose (Anserini spp.) remains from 15 archaeological sites in Japan (3400 bc to 1912 ad ) using binocular observation and histological analysis. We found medullary bone in two femora from the Oranda–shokan–ato site (1650–1850 ad ). The results indicate that the two femora were from domestic geese. By using secondary bone as an indicator of the domesticity of geese, knowledge regarding the origins of domestic geese can be expanded, and the morphological and/or genetic changes, as well as the domestication process, can be revealed. According to the literature, domestic geese were kept in Japan from the early eight century ad and were popular after the 17th century ad . The scarcity of medullary bone in the samples can be explained by the small number of domestic geese in Japan and/or by butchering practices that excluded the eating of breeding female geese. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
1000.
Sex determination using mandible parameters is population dependent. In order to assess which measurements better characterize sex in prehispanic individuals from the Canary Islands, we blindly contrasted the results obtained by visual inspection and osteometric measurements with those obtained by molecular sexing using amelogenin ancient DNA analysis on teeth from the same material. Unambiguous sex classification was achieved by amplification of sex specific amelogenin alleles in 56 out of 76 mandibles (73.78% of the cases). Visual inspection led to a correct diagnosis in 66.04% of cases, with a greater proportion of errors for female (54.17%) than male (17.24%) mandibles. Osteometric measurements were able to assign sex correctly in 72.2% in the best of cases (mandibular height), a proportion similar to that obtained using a discriminant function (71.2%). By logistic regression analysis, ramus breadth, index ramus breadth/ramus height and mandibular length were the parameters independently related with a mistaken diagnosis of female sex, whereas bigonial width, ramus height and mandibular length were the parameters more closely and independently related to a mistaken diagnosis of male sex. In conclusion, diagnosis based on visual examination of the mandible or on its metric measurement only serves to roughly estimate sex with an accuracy of around 70% or less, at least among the prehispanic population from Gran Canaria. Amplification of amelogenin alleles leads to unambiguous identification of male and female alleles in 73.68% of cases, at least among the prehispanic population from Gran Canaria.  相似文献   
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