全文获取类型
收费全文 | 484篇 |
免费 | 1篇 |
专业分类
485篇 |
出版年
2025年 | 1篇 |
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 17篇 |
2019年 | 15篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 4篇 |
2013年 | 31篇 |
2012年 | 29篇 |
2011年 | 29篇 |
2010年 | 29篇 |
2009年 | 22篇 |
2008年 | 22篇 |
2007年 | 27篇 |
2006年 | 27篇 |
2005年 | 13篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 18篇 |
2001年 | 20篇 |
2000年 | 16篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有485条查询结果,搜索用时 0 毫秒
91.
铜胎漆器在中国古代因实用功能的差异而拥有不同的品种。“漆衣铜镜”作为铜胎漆器的一个工艺品种,因其数量的鲜少而倍受漆器鉴赏家和研究者的关注。有一件凤纹漆衣铜镜由于长期浸泡于水中而得以较完整保存,出土后笔者首先对其损害状况和病因进行了分析,然后通过脱水保护处理,使这面铜镜达到较为稳定的保存状态。通过显微观察和电镜成分分析,确定漆彩绘至少存在4种不同的颜色。在分析研究的基础上,对其绘制图案进行了效果与工艺的复原。 相似文献
92.
长江中游地区楚墓中出土的青铜箭镞的锈蚀现象及锈蚀机理研究 总被引:1,自引:0,他引:1
青铜箭镞是古代制造量最大、一次性使用的兵器,与要求甚高的青铜剑和青铜礼乐器等相比,在选材和表面处理等方面有很大的不同,其锈蚀过程最能反映材料在经过数千年后所产生变化。长江中下游地区环境潮湿,埋藏条件复杂,本研究利用扫描电子显微镜(SEM)、能谱仪(EDS)、X-射线衍射仪(XRD)、显微硬度等分析测试技术,从材料科学的角度对长江中游地区战国晚期古墓中出土的青铜箭镞的锈蚀现象和锈蚀机理进行了全面的研究和分析,以期为古代青铜器的保护提供更准确的信息和资料。结果表明,青铜箭镞的组织结构可分为完全矿化层、过渡层和心部原始材料等三个特征层,不同特征层具有不同的显微组织、化学成分、致密性,以及显微硬度等;并沿横截面观察和分析了锈蚀层中的微裂纹的性质和产生原因,即,平行于表面的裂纹是由矿化层氧化物膨胀引起的剥离开裂,其进一步发展将形成“粉状锈”,而垂直于表面呈放射状的裂纹是当圆柱形箭镞杆膨胀时,矿化层的塑性差,抗变形能力低而产生的开裂;锈蚀机理研究认为青铜器的锈蚀过程是环境中杂质元素通过过渡层沿界面能较高的α固溶体和(α+δ)共析体晶界或孔隙等缺陷逐步向内部扩散的结果。 相似文献
93.
近年来,杭州出土了一批白釉瓷器残片,特别是一些具有定窑风格的白瓷样品引发了众多考古工作者和古陶瓷爱好者的关注与浓厚兴趣。为探究其制作年代和产地,采用热释光技术和X射线荧光无损分析技术相结合的方法对一批杭州出土具有定窑风格的白瓷样品进行了检测分析。测试结果表明,这批白釉瓷片样品制作年代约处在北宋末年到南宋早期,胎的化学组成中Al2O3含量较高,最低24.78%,最高达33.06%,具备北方瓷器特点;胎中微量元素Rb、Sr、Zr含量的比例以及钙镁碱釉的特征与河北曲阳定窑极为相似。综合文献及其它人文考证,这批杭州出土的白瓷应该为北宋晚期至南宋早期产自于河北的定窑瓷器。此分析结果也将为研究宋金贸易及文化提供科学依据。 相似文献
94.
Burnt daga structures in Iron Age villages serve as proxies for severe drought on the plateau of southern Africa. The distribution of burnt daga remains in two other rainfall areas, KwaZulu-Natal and the Inter-Tropical Convergence Zone over Zimbabwe, Zambia and Malawi, establishes a sequence of simultaneous burnings that parallels the severe droughts recorded for the interior plateau. These widespread correspondences suggest a common cause. Another correspondence with natural proxy data from South America indicates that intensive El Niño events most likely caused the droughts. 相似文献
95.
古代铜镜的透光原理一直存在争议,本作通过大量实践证明,古铜镜的透光效应与铸态曲率无关,而与铜镜在加工研磨过程中产生的新的镜面曲率有关。 相似文献
96.
S. Shalev E. N. Caspi S. Shilstein A. M. Paradowska W. Kockelmann T. Kan‐Cipor Meron Y. Levy 《Archaeometry》2014,56(2):279-295
Thirteen bronze battleaxes from Middle Bronze Age II graves at Rishon LeZion, Israel were analysed by ED XRF at multiple surface locations in order to determine their metallurgical composition. Six of these were further subjected to neutron diffraction using an ENGIN‐X diffractometer in order to determine bulk phase composition. The results indicate that the previously established geographical and chronological variability in Sn–Cu (with occasional Pb) and As–Cu alloys found using the former method may be an artefact of preservation and conservation. In addition, the varying homogeneity determined by the latter reflects special treatment for improving on the metal cast. 相似文献
97.
Jeffrey P. Emanuel 《巴勒斯坦考察季》2013,145(4):265-280
Primary sources from the end of the Bronze Age have long been read as suggesting a time of chaotic transition, particularly with regard to threats from the sea that the established powers had no means of combatting. While the scale and severity of seaborne attacks seems to have increased in the late 13th century, these were not in themselves new phenomena, as a state of maritime threat seems to have been a constant for coastal polities and mariners in the Late Bronze Age eastern Mediterranean. However, a combination of internal and external factors in the late 13th and early 12th centuries combined to make these attacks more effective than they had been in the past, and polities more vulnerable to them. These included the rapid spread of improvements in maritime technology, particularly from the Aegean and the Levant, via high–intensity ‘zones of transference’, as well as an increase in the scale of ship–based combat operations, due in part to the displacement of people during the Late Bronze Age collapse. This paper addresses this in two parts, beginning with the ‘background’ evidence for a constant state of maritime threat in the centuries leading up to the end of the Bronze Age, and concluding with the ‘foreground’ evidence for zones of transference and the transmission of groundbreaking elements of naval technology in the years surrounding the Late Bronze–Early Iron Age transition. 相似文献
98.
AbstractThis article examines advanced ages at death in a historical population in northern Sweden between 1780 and 1900. The source material used is a set of data files from the Demographic Data Base at Umeå University supplemented with the search tool Indiko. The belief that the Sami died at very old ages was tested, and life tables and values of remaining life expectancies at older ages were calculated. The information of the age at death was analysed using a model containing four levels of certainty. The analysis reveals that the Sami did not live to extreme ages. The analysis also reveals large differences between the parishes concerning extreme longevity and correctness of age at death. 相似文献
99.
G. Piga A. Malgosa T.J.U. Thompson M. Guirguis S. Enzo 《International Journal of Osteoarchaeology》2015,25(2):146-159
A series of graves belonging to the Phoenician period were investigated after the campaign excavation of 2007 in the Phoenician‐Punic necropolis of Monte Sirai (Carbonia, Sardinia, Italy). One tomb in particular (labelled 252) is presented here because of its uniqueness. Tomb 252 contained the cremated remains of an individual, probably male, and comparison of the excavation records alongside reconstruction of the bone material itself makes clear that the individual was cremated in a prone position. It represents the first case of prone cremation reported in the literature. To investigate whether the temperature of the cremation was homogenous across the entire body, we have conducted a combined physical–chemical analysis using X‐ray diffraction spectroscopy and Fourier transform infrared. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
100.
浑仪、简仪(以下简称两仪)在高PH、大气污染和日晒雨淋环境中的腐蚀是一种动态加速腐蚀过程。采用合成的双唑胺铜缓蚀剂和有机硅改性的甲基丙烯酸树脂,并分别复配成协同缓蚀剂群和含有增效稳定剂的封护剂。采用这两种材料和脱水后再防护的工艺,使带锈防护后的浑仪、简仪的腐蚀低于无污染大气中的速率。用电化学方法评价了防护技术的可行性,根据腐蚀与人工老化试验结果讨论了防护材料性能与腐蚀环境和带锈防护的关系,采用XPS分析方法探索了双唑胺比BTA更适用于两仪防护的原因。 相似文献