全文获取类型
收费全文 | 120篇 |
免费 | 6篇 |
专业分类
126篇 |
出版年
2023年 | 2篇 |
2021年 | 1篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 10篇 |
2013年 | 17篇 |
2012年 | 5篇 |
2011年 | 9篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 2篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有126条查询结果,搜索用时 0 毫秒
61.
62.
The current research is aimed at determining the nature of changes in the dimensions and hygroscopicity of archaeological Scots pine (Pinus sylvestris L.) wood after treatment with polyethylene glycols and vacuum freeze-drying. The research was undertaken on mature sapwood with narrow annual rings and a small percentage of latewood. The experimental material used in a comparative assessment is characterised by a considerable degree of wood degradation, but low tangential and radial shrinkage and relatively high longitudinal shrinkage. The waterlogged samples were treated with aqueous solutions of PEG 300 with final concentrations: 8, 12, 16 and 20% (v/v), to which PEG 4000 with final concentration: 15, 20 and 25% (w/v) was added. After freeze-drying and seasoning of samples in the air at RH 30, 40, 50 and 65%, the water content of the samples and the degree of shrinkage of wood in three anatomical directions were determined. The dimensional stability of the samples was also determined on the basis of ASE values at RH 50%. 相似文献
63.
Piotr Weckwerth Krzysztof Przegiętka Alicja Chruścińska Barbara Woronko Hubert L. Oczkowski 《Geochronometria》2011,38(4):397-412
The deposits of the Toruń Basin are dominated by a few-metre thick sand series which fill up buried valley-like depressions.
In many cases they underlie the Weichselian till which builds up the ice marginal streamway (pradolina) terraces or they are
exposed at the basin slopes. As the results of the geological and sedimentological studies, as well as of the dating of the
deposits at the sites in the Toruń Basin indicate, the deposits include two fluvial series accumulated before the advancement
of the Leszno Phase ice sheet, i.e. in Middle Weichselian and at the beginning of Late Weichselian. The oldest fluvial series
connected with the Saalian Glaciation was found at the mouth section of the Drwęca Valley. The fluvial system of the Toruń
Basin during Middle Weichselian and at the beginning of Late Weichselian developed in two phases of the sand-bed braided river.
During the first one the river channel were dominated by large mid-riverbed sandbars, while during the second phase the water
flow was smaller and, as a result, low transverse sandbars and two-dimensional dunes developed. Other active river channel
also showed low-energy flows, more intensive meandering than in the case of the braided rivers, as well as sandy side-bars.
Analysis of the rounding and frosting of the quartz grains indicate that the studied series of the Weichselian sandy deposits
represent alluvia of a river which were fed from two diverse sources. The first one might have represented the alluvia of
a warm river which transformed its load, while the other one might have mainly carried the underlying Quaternary deposits. 相似文献
64.
65.
66.
M. Janeczek A. Chrszcz V. Onar R. Henklewski J. Piekalski P. Duma A. Czerski I. Cakosiski 《International Journal of Osteoarchaeology》2014,24(5):623-633
The investigation were carried out on the medieval horses thoracic and lumbar spine excavated between 2009‐2011 by the Institute of Archaeology, University of Wroclaw at New Market Square in Wroclaw (Wratislavia, Breslau), capital city of the Polish province of Lower Silesia. The pathological changes, like: ankylosis of the zygapophyses, fusion of the vertebral bodies and arches and the interspinal space calcification were observed. The X‐ray examination was done. During medieval artefact interpretation the biomechanical aspect of horse's locomotor system was taken into consideration. The archaeozoological material was compared with modern horse's spine (with similar pathological changes and known history of disease). The analysis proved, that the observed osseous reaction was a result of the long‐lasting inflammation. Such a disease appearance accompanies chronic inflammatory state of errector muscles of the spine. It is typical for those horses utilised for the saddle. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
67.
Zuzanna Kabacińska Ryszard Krzyminiewski Danuta Michalska Bernadeta Dobosz 《Geochronometria》2014,41(2):112-120
This study presents the preliminary results of investigation of the lime mortars and plasters from archaeological excavations in Hippos (Israel), using Electron Paramagnetic Resonance (EPR) spectroscopy. The research was conducted in order to characterize the building material and its reaction to ionizing radiation. The ancient settlement Hippos, situated on the east shore of the Sea of Galilee, functioned from the 3rd cent. BC until it was destroyed by the earthquake in 749 AD. Lime mortars and plasters show carbonate and locally gypsum character of binder and different kind of aggregate. Samples were γ-irradiated and measured using X-band EPR spectrometer. Computer Resolution Enhancement Method was applied to the complex spectra. Some of the γ-induced EPR signals were attributed to CO2 ? and CO3 3? paramagnetic centres. Exponential growth of the dose response curve above 1 kGy and saturation for doses above 20 kGy was observed. For doses lower than 1 kGy the dose response curve has a linear character. The presence of γ-sensitive carbonate paramagnetic centres could indicate that, after further studies, well-chosen samples of mortars and plasters might be suitable for EPR dating, assuming the centres have been sufficiently bleached during the manufacturing process. 相似文献
68.
Alicja Chruścińska Anna Cicha Natalia Kijek Piotr Palczewski Krzysztof R. Przegiętka Krystyna Sulkowska-Tuszyńska 《Geochronometria》2014,41(4):352-360
Saint James Church in Toruń is one of the most important gothic monuments in Poland. The date of the beginning of its construction is known from historical reports but the earlier history of the site remains undiscovered. During the archaeological excavations in years 2010 and 2011 five brick samples were collected for luminescence dating as well as four additional samples from the brick surroundings for the dose rate estimation. The equivalent dose was determined by TL and OSL methods. The TL results differ significantly from the OSL results but the last ones are verified by historical knowledge and radiocarbon dating. Establishing the dose rate from gamma rays needs a special attention because of the complex course of the foundations of the church. The details of the applied approach are presented in the current work. The results obtained indicate that a solid brick construction existed at the site of the presbytery of the Saint James Church before it was build. 相似文献
69.
We conducted an identification of a substance isolated from a T‐shaped ornamental element excavated from a Globular Amphora Culture tomb at the Kowal 14 archaeological site in Poland. 14C dating indicated 4105 ± 35 bp (POZ‐21912) and 3990 ± 50 bp (POZ‐21910). Analytical methods such as SEM–EDS, XRD and FT–IR were applied to study the origin of its structure. The results of instrumental analysis and the archaeological context indicate that the adhesive substance investigated consists mainly of calcium carbonate (calcite, 78–88%), silica dioxide (quartz), sodium aluminium silicate (albite) and potassium aluminium silicate (microcline). The material might be a man‐made, mineral adhesive, a kind of lime mortar. The object is considered as the oldest European finding of this type outside the Mediterranean Basin. It provides evidence for the use of the lime calcination process in Central Europe as early as in the Late Neolithic, for which there were—up to now—no convincing premises. 相似文献
70.