首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   281篇
  免费   17篇
  2024年   1篇
  2023年   2篇
  2022年   1篇
  2021年   3篇
  2020年   6篇
  2019年   17篇
  2018年   21篇
  2017年   12篇
  2016年   2篇
  2015年   3篇
  2014年   25篇
  2013年   106篇
  2012年   17篇
  2011年   9篇
  2010年   5篇
  2009年   7篇
  2008年   8篇
  2007年   6篇
  2006年   5篇
  2005年   3篇
  2004年   4篇
  2002年   3篇
  2001年   5篇
  1998年   1篇
  1996年   1篇
  1995年   1篇
  1994年   4篇
  1992年   1篇
  1991年   2篇
  1990年   3篇
  1989年   1篇
  1983年   1篇
  1981年   2篇
  1980年   6篇
  1979年   4篇
排序方式: 共有298条查询结果,搜索用时 171 毫秒
81.
刘超建 《中国边疆史地研究》2020,(1):117-127,215,216
晚清民国乌鲁木齐地区的村落,根据人口结构不同,可以分为宗族、地理相近与地理相错三种类型。由于三种类型村落的自治程度不同,造成了政府对其治理方式上存在区别,也突出了国家对其控制力上存在差别。文章主要以村落个案分析为中心,针对每种类型的村落,以个案的形式说明村落类型与治理之间的关系及反映出的乡村社会治理的空间差异性。  相似文献   
82.
R. Thér 《Archaeometry》2016,58(2):222-238
The relationship between forming techniques and orientation of the components of ceramic materials in the context of pottery technology has long been recognized and used for identification of the techniques employed to create archaeological ceramics. The alignment of inclusions is usually characterized by qualitative categories or ordinal scales. This paper evaluates the potential of quantitative orientation analysis for identification of pottery‐forming techniques. A collection of experimental pottery formed using five forming techniques and combined techniques was analysed. The forming techniques were characterized by the intervals of the mean direction and the circular standard deviations of the orientation of the major axes of the ellipses equivalent to the objects representing random sections of inclusions and voids. The most informative criteria for the identification of pottery techniques are the circular standard deviation of the inclusion/void orientations in the core area of the vessel wall in a perpendicular thin section and the mean direction in a tangential section.  相似文献   
83.
The most crucial parameter to be determined in an archaeological ground‐penetrating radar (GPR) survey is the velocity of the subsurface material. Precision velocity estimates comprise the basis for depth estimation, topographic correction and migration, and can therefore be the difference between spurious interpretations and/or efficient GPR‐guided excavation with sound archaeological interpretation of the GPR results. Here, we examine the options available for determining the GPR velocity and for assessing the precision of velocity estimates from GPR data, using data collected at a small‐scale iron‐working site in Rhode Island, United States. In the case study, the initial velocity analysis of common‐offset GPR profile data, using the popular method of hyperbola fitting, produced some unexpectedly high subsurface signal velocity estimates, while analysis of common midpoint (CMP) GPR data yielded a more reasonable subsurface signal velocity estimate. Several reflection analysis procedures for CMP data, including hand and automated signal picking using cross‐correlation and semblance analysis, are used and discussed here in terms of efficiency of processing and yielded results. The case study demonstrates that CMP data may offer more accurate and precise velocity estimates than hyperbola fitting under certain field conditions, and that semblance analysis, though faster than hand‐picking or cross‐correlation, offers less precision.  相似文献   
84.
85.
对郑州商文化陶字符量化分析结果显示,早商文化陶字符使用以具有首都地位的郑州早商文化遗址最为集中,具有较强的地域性。郑州早商文化陶字符分期演进中出现一些分界现象,缘于商文化的兴盛和文化中心的转移。郑州商文化陶字符多出现于祭祀场所和手工业作坊遗址具有特殊意义的遗迹,表明其主要为生活、手工业生产、祭祀活动中有关数量、日期、位序、族属、地点等信息的记录遗存。  相似文献   
86.
本工作旨在了解贾湖单人墓随葬品数量与墓主人性别、年龄以及墓葬分期之间的关系。根据墓葬样本的实际情况,本工作使用t-检验、单因素和双因素方差分析的方法进行了初步的统计学分析。结果显示,贾湖墓葬随葬品总量与性别无关,但与墓主人的死亡年龄有关,壮年随葬品较丰富。同时,随葬品数量受到性别和死亡年龄的交互影响比较显著,女性少年儿童的随葬品数量最多,男性壮年的随葬品次之。从随葬品的种类上看,除少年儿童组最多外,女性壮年墓葬占有石制品最多;男性壮年墓葬占有骨、牙制品最多。本工作还发现陶器和骨、牙制品的数量在不同时期存在着较显著变化,第二期时骨、牙制品和陶制品的数量较多。本工作认为,女孩随葬品数量较多的情况可能与母系氏族社会重女习俗有关,不同性别的壮年侧重随葬不同质地的物品则可能暗示着贾湖先民们已经出现了一定程度的社会分工,陶和骨、牙制品在第二期时比较丰富的现象可能与这一时期渔猎采集活动较活跃有关。  相似文献   
87.
“华光礁一号”南宋沉船船板中硫铁化合物分析   总被引:1,自引:0,他引:1  
鉴于硫铁化合物对海洋出水木质文物的特殊危害,通过 X射线衍射(XRD)、等离子体发射光谱(ICP-AES)和 X射线光电子能谱(XPS)等分析手段,对“华光礁一号”南宋沉船船板残块中的硫铁化合物进行了分析研究。结果表明,所采集的样品中含有大量的 Fe和 S元素,并且其分布深度至少可达 4cm。两种元素的化学状态基本可分为铁的氧化物、硫铁化合物、硫酸盐和其它还原性硫四大类。其中,硫铁化合物主要以 FeS和 FeS2形式存在,并已部分氧化成硫酸盐。因此,在后续的保护处理过程需着重对其酸化过程进行控制,以有利于文物的长期保存。  相似文献   
88.
The Longmen Grottoes, also known as the Longmen Caves or Dragon's Gate Grottoes, are located near the city of Luoyang, Henan province, China. The grottoes were carved into the limestone cliffs during the period from 493 AD to 1130 AD. Limestone samples from different areas within the grottoes were analyzed by neutron activation analysis (NAA) to determine the concentrations of major, trace and rare-earth elements (REEs). Three compositional groups were identified corresponding to different areas within Longmen Grottoes. X-ray diffraction (XRD) was performed on a few samples to obtain information about the mineral structure. The results indicate that rocks in the northern area are comprised of dolomite, while rocks in the middle and southern areas are comprised of limestone. The NAA results provide information useful for identifying and relocating fragments from the grottoes that may have lost their identity. The compositional data also provides important clues regarding the geologic history of the limestone formation at Longmen.  相似文献   
89.
Archaeologists have known that an obsidian source exists in the Dasht-i-Nawur basin of central Afghanistan since at least the 1970s; however, regional political turmoil and instability have prevented in-depth study of this source. Data presented here from recent analyses of archival specimens of obsidian collected during a 1976 survey provide a preliminary geochemical profile for this obsidian source. These data suggest that the Dasht-i-Nawur source is easily distinguishable from other obsidian sources in the Near East and southwest Asia. Comparison of these data to an existing database of artifact compositional profiles suggests that initial hypotheses about restricted distribution of the Dasht obsidian may be correct. These data provide for the first time the characterization of a long-known but poorly studied obsidian source. Additionally, this study serves as one example of the benefits gained through working to maintain and preserve data archives of now-closed laboratories.  相似文献   
90.
Neutron tomography (NT) has been applied to visualize the inner structure of ancient Portuguese glazed tiles undergoing conservation treatments. Neutrons have the advantage of interacting strongly with hydrogen, so NT is able to map hydrogenous compounds with high sensitivity. The present study explores its potential for assessing the distribution of the consolidant Paraloid B-72 inside tiles, to evaluate the efficiency of two different methods of treatment: brushing and immersion in solution. Using a prototype NT setup at the Reactor Português de Investigação (Sacavém, Portugal), each two-dimensional image is obtained from a 90 s exposure, at a thermal neutron flux of 2 × 105 n cm−2 s−1 at the irradiation site. The neutron beam has a diameter of 5 cm, so fragments with outer dimensions up to 4.8 cm can be inspected. Samples are automatically rotated by an angle of 0.9° between successive images. Images were obtained before and after the application of the consolidant. The results obtained show that: (i) NT is a useful tool for visualization of the inner structure of ancient glazed tiles, and to assess penetration depth of consolidant and its distribution inside the tile; and (ii) brushing with 10% Paraloid® B-72 in acetone solution appears to be more efficient than immersion. Neutron tomography showed a greater and more uniform retention of resin inside the tile if the brush is used to apply the consolidant, to increase the cohesion of the object.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号