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   735篇
  免费   52篇
  2024年   1篇
  2023年   7篇
  2022年   8篇
  2021年   20篇
  2020年   30篇
  2019年   39篇
  2018年   47篇
  2017年   51篇
  2016年   42篇
  2015年   30篇
  2014年   28篇
  2013年   118篇
  2012年   43篇
  2011年   47篇
  2010年   39篇
  2009年   39篇
  2008年   26篇
  2007年   38篇
  2006年   22篇
  2005年   21篇
  2004年   19篇
  2003年   19篇
  2002年   20篇
  2001年   8篇
  2000年   9篇
  1999年   6篇
  1998年   3篇
  1997年   1篇
  1996年   3篇
  1994年   1篇
  1979年   1篇
  1978年   1篇
排序方式: 共有787条查询结果,搜索用时 31 毫秒
41.
New challenges in management and restoration of archaeological sites require the utilization of advanced technologies and systems to assist in preserving the important legacy of human heritage. These challenges include monitoring and preserving of site landscapes, maintenance and rehabilitation of archaeological structures, and quality and safety management. In this research, an integrated methodology based on photogrammetry and Three-Dimensional (3D) Geographic Information System (GIS) is developed to capture and model essential details needed for the proper management of archaeological sites. Recent advances in digital imagery and modelling utilize photogrammetry as an efficient technique for 3D modelling of archaeological sites to derive accurate measurements of size, shape, position, and texture of objects using two-dimensional digital photographs. Spatial data that include aerial stereo photographs, satellite images, close-range photos, terrestrial surveying and Global Positioning Systems (GPS) are integrated within the design of the proposed model. The approach is validated with a case study of Ajloun Castle, one of the ancient and important preserved structures located in Jordan. Various sequential levels of details have been developed for the castle: Orthophoto, Digital Elevation Model (DEM), structures geometry and site layout and 3D textured model. The suggested methodology is expected to be efficient in modelling and documenting archaeological structures. The developed model is utilized to assess the management of archaeological structures through feasibility analysis, rehabilitation decisions, and safety planning.  相似文献   
42.
43.
为了更清楚地展示秦始皇帝陵地区考古地层的三维空间关系,并为后期考古工作中空间数据挖掘做准备,借鉴三维地质建模技术,提出了考古地层三维建模方法。基于探孔数据构建了考古地层三维模型。该模型清楚地展示了秦始皇帝陵地区考古地层的三维空间关系,为田野考古数字化工作提供一种新思路、新方法。  相似文献   
44.
为了制定山西省万荣县寿圣寺塔的保护规划方案,需制作具有真实纹理的三维模型,但砖塔等大型不可移动文物的三维重建难度很大,制作成本一直很高。为此,本研究运用无人机拍摄和地面拍摄多视角影像的技术,制作寿圣寺塔的三维模型,生成各个立面的正射影像图,量算砖塔的高度、宽度等尺寸数据,为这类文物的三维重建提供一种新的技术和方法。  相似文献   
45.
古建筑三维重建已成为历史遗迹保护与修复的重要内容。为了探讨三维激光扫描数据的获取流程、数据处理方法,以三维激光扫描获取的大雁塔海量点云数据为例,研究了古建筑三维重建中点云数据获取与处理的详细过程。联合Cyclone、AutoCAD和3D-Max软件的优点构建了大雁塔真实的横面、剖面、立面模型,其中重点研究了海量点云数据在Cyclone软件中分块建模的方法。结果表明:将拼接好的大雁塔海量点云数据分块建模,不仅加快了数据处理的速度,而且符合精度要求。在点云数据拼接时采用标靶拼接和同名点拼接相结合及测站间两两拼接之后再整体拟合平差的方法,减少了拼接中的误差,使每站拼接误差都不超过3cm。在建模过程中的墙体拟合是上万个点云经过平差计算得到,精度高达2mm。最后在3D-Max软件中组合、渲染和贴图,真实地构建了大雁塔三维立体模型。为古建筑数字化存档和后期的修缮工作提供了重要的依据。  相似文献   
46.
Oral cleft (OC) is a common congenital anomaly in humans, which occurs in approximately one per 700 live births. However, cleft skulls are found relatively seldom in archaeological specimens, especially for the bc period. Mortality of infants with OC was apparently high because of breastfeeding difficulties and culturally sanctioned rejection of them in the past. This paper presents one of the most ancient cases of OC in Eurasia. The finding comes from the Middle Bronze Age pastoralists' cemetery in Altai, Russia. The skeletal remains have been radiocarbon dated to 1883–1665 cal bc . Cranial and dental measurements, computed tomography and radiography have been used to examine this malformation. The facial sculpting reconstruction has been performed to visualise the ante mortem appearance of the cleft face. Besides, δ13C and δ15N isotope analysis was used for a comparative study of the diet of the cleft individual. It has been established that a young man from Altai was affected by complete bilateral cleft lip and alveolus, which is a very rare form of typical OC. This defect is associated with dental anomalies such as hypodontia, microdontia, and ectopia as well as with dysmorphology of the facial complex outside the cleft area, including mild hypertelorism, hypoplasia of nasal bones and antheroposterior maxillary deficiency. Furthermore, aplasia of the frontal sinuses and the sacral spina bifida occulta have been observed. These findings are consistent with clinical data indicating strong correlation between development of a major defect and multiple minor anomalies. The results of the study also suggest that there was tolerant attitude towards the facial deformities among the ancient Altai pastoralists. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
47.
48.
Why at this particular historical moment has there emerged a rousing interest in the potential contribution of diasporas to the development of migrant sending states and why is this diaspora turn so pervasive throughout the global South? The central premise of this paper is that the rapid ascent of diaspora‐centred development cannot be understood apart from historical developments in the West's approach to governing international spaces. Once predicated upon sovereign power, rule over distant others is increasingly coming to depend upon biopolitical projects which conspire to discipline and normalize the conduct of others at a distance so as to create self‐reliant and resilient market actors. We argue that an age of diaspora‐centred development has emerged as a consequence of this shift and is partly constitutive of it. We develop our argument with reference to Giorgio Agamben's “Homo Sacer” project and in particular the theological genealogy of Western political constructs he presents in his book The Kingdom and the Glory (2011). We provide for illustration profiles of three projects which have played a significant role in birthing and conditioning the current diaspora option: the World Bank's Knowledge for Development Programme (K4D); the US‐based International Diaspora Engagement Alliance (IdEA); and the EU/UN Joint Migration and Development Initiative Migration4Development project (JMDI‐M4D). Drawing upon economic theology, we make a case for construing these projects as elements of the West's emerging Oikonomia after the age of empire.  相似文献   
49.
The grave of La Balance-Ilot P, in Avignon, southern France, is an individual and isolated burial, attributed in the 1970′s to the Mesolithic or the Early Neolithic. The grave, partially unearthed, was exhibited and stored at the Calvet Museum until its rediscovery and laboratory excavation in 2009. We used 3D laser recording and field anthropological methods, followed by a multidisciplinary approach. The deceased, an adult male, was buried in primary deposition without any architectural features preserved. For the first time in the Mediterranean early Neolithic, this study led to the identification of a garment adorned with sophisticated embroidery using 158 red-colored Columbella rustica shells and 16 red deer canines. Calibrated AMS dates allow us to reliably place it in the early 5th millennium b.c. reinforcing evidence for long distance intercultural relationships in Europe during the Neolithic.  相似文献   
50.
X. Zhou  T. J. Burbey 《Geofluids》2014,14(2):174-188
The initiation of hydraulic fractures during fluid injection in deep formations can be either engineered or induced unintentionally. Upon injection of CO2, the pore fluids in deep formations can be changed from oil/saline water to CO2 or CO2 dominated. The type of fluid is important not only because the fluid must fracture the rock, but also because rocks saturated with different pore fluids behave differently. We investigated the influence of fluid properties on fracture propagation behavior by using the cohesive zone model in conjunction with a poroelasticity model. Simulation results indicate that the pore pressure fields are very different for different pore fluids even when the initial field conditions and injection schemes (rate and time) are kept the same. Low viscosity fluids with properties of supercritical CO2 will create relatively thin and much shorter fractures in comparison with fluids exhibiting properties of water under similar injection schemes. Two significant times are recognized during fracture propagation: the time at which a crack ceases opening and the later time point at which a crack ceases propagating. These times are very different for different fluids. Both fluid compressibility and viscosity influence fracture propagation, with viscosity being the more important property. Viscosity can greatly affect hydraulic conductivity and the leak‐off coefficient. This analysis assumes the in‐situ pore fluid and injected fluid are the same and the pore space is 100% saturated by that fluid at the beginning of the simulation.  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