全文获取类型
收费全文 | 4205篇 |
免费 | 160篇 |
出版年
2020年 | 68篇 |
2019年 | 85篇 |
2018年 | 115篇 |
2017年 | 126篇 |
2016年 | 123篇 |
2015年 | 93篇 |
2014年 | 94篇 |
2013年 | 1063篇 |
2012年 | 128篇 |
2011年 | 125篇 |
2010年 | 104篇 |
2009年 | 140篇 |
2008年 | 166篇 |
2007年 | 115篇 |
2006年 | 87篇 |
2005年 | 54篇 |
2004年 | 60篇 |
2003年 | 55篇 |
2002年 | 51篇 |
2001年 | 88篇 |
2000年 | 60篇 |
1999年 | 58篇 |
1998年 | 38篇 |
1997年 | 26篇 |
1996年 | 46篇 |
1995年 | 45篇 |
1994年 | 37篇 |
1993年 | 45篇 |
1992年 | 28篇 |
1991年 | 34篇 |
1990年 | 28篇 |
1989年 | 39篇 |
1988年 | 38篇 |
1987年 | 41篇 |
1986年 | 37篇 |
1985年 | 41篇 |
1984年 | 49篇 |
1983年 | 58篇 |
1982年 | 44篇 |
1981年 | 40篇 |
1980年 | 45篇 |
1979年 | 36篇 |
1978年 | 47篇 |
1977年 | 44篇 |
1976年 | 52篇 |
1975年 | 27篇 |
1974年 | 27篇 |
1973年 | 28篇 |
1972年 | 30篇 |
1971年 | 30篇 |
排序方式: 共有4365条查询结果,搜索用时 15 毫秒
991.
Geoffrey D. Dunn 《The Journal of religious history》2015,39(1):1-13
Evidence for the conflict between two rival candidates for the bishopric of Rome following the death of Zosimus at the end of 418 comes from a group of twenty‐five letters, most of which are official letters to and from Emperor Honorius (the rest being from other imperial officials and the emperor's sister), all but one of which are found in the Collectio Avellana. Interestingly, we have nothing preserved from the two episcopal claimants about this matter. The group of letters chronicle imperial concern for the preservation of public order. Do we have here an example of imperial interference in episcopal elections in Rome? In this article a careful examination of the letters reveals that Honorius was concerned only that the Roman church's procedures had been followed (Collectio Avellana, Ep. 15), which should determine who was lawful bishop. Sociological Conflict Theory is employed to investigate the nature of the evidence to address issues of the nature of the dispute and its participants, what values were contested, how it escalated, and how it was resolved. Such an approach makes clear that our evidence focuses on the role of the emperor and only incidentally tells us of the thinking and strategy of the two candidates. The final decision was made not on the merits of the candidates and the legality of one of the two elections, but upon Eulalius' violation of the conditions imposed upon the two rivals while the dispute was to be settled. Despite the emperor's concern only to facilitate the church settling this conflict itself, in the end it was an imperial measure that determined the outcome of the disputed election. 相似文献
992.
993.
Spectrochemical Characterization of Red Pigments Used in Classic Period Maya Funerary Practices
下载免费PDF全文
![点击此处可从《Archaeometry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
P. Quintana V. Tiesler M. Conde R. Trejo‐tzab C. Bolio J. J. Alvarado‐gil D. Aguilar 《Archaeometry》2015,57(6):1045-1059
We studied the composition, colour chromaticity and form of application of red pigments in human bone samples from seven Classic period Lowland Maya sites. The samples were analysed by X‐ray diffraction, scanning electron microscopy (SEM) and X‐ray energy‐dispersive spectroscopy (EDS). Colour was measured using conventional colour identification standards (Munsell) and reflectance spectroscopy. Cinnabar and hematite were identified as the pigments used. We conclude that the reflectance method has advantages over conventional visual results, as it provides precise, objective and quantifiable optical data to distinguish the chromaticity, colour saturation and brightness of the pigments. 相似文献
994.
Bells of copper and copper alloys and gold–copper alloys were deposited in events at the Cenote Sagrado at Chichén Itzá, Mexico during the site's primary occupation (ad 750–1050) and in later centuries. Housed in three museums in the United States and Mexico, bells (n = 38) were evaluated for traces of fabrication and alteration using Vis–UV–IR optical microscopy. Bulk compositions were determined through p‐ED‐XRF. Phases and compositional variation by depth were characterized through XRD and RBS. The technological styles of bell groups were ascribed to communities of metallurgical practice, from West and Central Mexico to Costa Rica and Panama. 相似文献
995.
A Multidisciplinary Approach for the Archaeometric Study of Pozzolanic Aggregate in Roman Mortars: The Case of Villa dei Quintili (Rome,Italy)
下载免费PDF全文
![点击此处可从《Archaeometry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
C. M. Belfiore G. V. Fichera M. F. La Russa A. Pezzino S. A. Ruffolo G. Galli D. Barca 《Archaeometry》2015,57(2):269-296
This contribution focuses on the study of historical mortars from a Roman archaeological site known as Villa dei Quintili, a monumental villa located in the south‐eastern part of Rome (Italy). The study was carried out on 38 mortar samples, collected from several edifices within the complex. A multi‐analytical approach, including polarized optical microscopy, scanning electron microscopy coupled with energy‐dispersive system and laser ablation inductively coupled plasma mass spectrometry, was used to analyse the pozzolanic material used for the preparation of mortars. Data obtained on both major and trace elements were compared with the compositions of Pozzolana Rossa, Pozzolana Nera and Pozzolanella samples from the Alban Hills volcanic district, collected from a historic quarry nearby, as well as with literature data. The results of such a multidisciplinary approach allowed us to recognize the use of all three pozzolan types for the aggregate fraction of examined mortars from the Villa dei Quintili. 相似文献
996.
A Multi‐Method Database of the Black and White Marbles of Göktepe (Aphrodisias), Including Isotopic,EPR, Trace and Petrographic Data
下载免费PDF全文
![点击此处可从《Archaeometry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A database of the ancient marbles of Göktepe near Aphrodisias is reported, and includes 160 white, black and bichrome samples from 13 quarries and two waste deposits. The quarries are grouped into four districts. Districts 1 and 2, to the north, produced exclusively black or dark grey marbles (nero antico). Districts 3 and 4 produced white statuary marble. Nero antico and a black and white stone were also quarried in district 4, where the black marble surfaces again. The samples were characterized using petrography, isotopic analysis, EPR spectroscopy and trace analysis. The Göktepe white exhibits an unparalleled combination of fine grain, low EPR intensity and high strontium concentration that often allows easy identification. The isotopic values are less distinctive and similar to those for Carrara. In most cases, however, they are tightly grouped and also quite indicative. The black marbles exhibit a much weaker metamorphic overprint. With respect to the white marbles, they show analytical similarities but also notable differences. Therefore, establishing their provenance can be more difficult and may require the support of petrographic analysis. The results suggest that the Göktepe marbles were among the most prized and widespread statuary marbles used in Roman times, particularly from the early second century ad onwards. 相似文献
997.
998.
999.
1000.
Diagenesis and elemental geochemistry under varying reservoir oil saturation in the Junggar Basin of NW China: implication for differentiating hydrocarbon‐bearing horizons
下载免费PDF全文
![点击此处可从《Geofluids》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this paper, we attempt to differentiate hydrocarbon‐bearing reservoir horizons of the Junggar Basin of NW China based on the characteristics of diagenesis and associated elemental geochemistry. Reservoirs at this site have varying levels of oil saturation that correlate with the degree of dissolution in minerals (e.g., calcite and feldspar). Four different horizons with varying diagenetic mineral assemblages were observed, including (i) kaolinite‐rich, oil‐dominated horizons, (ii) kaolinite–pyrite–hematite‐rich, oil–water‐dominated horizons, (iii) siderite–chlorite‐rich, water‐dominated horizons, and (iv) chlorite‐rich horizons with negligible hydrocarbon production. The mean MnO content of the representative diagenetic mineral (e.g., calcite) in each of the above horizons is >2.5, 2.0–2.5, 1.5–2.0, and <1.0 wt%, respectively. We propose that the above methodology can be used for the identification of reservoir hydrocarbon‐bearing horizons. We argue that the indicators presented here can be applied in oil exploration across the Junggar Basin. 相似文献