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   121篇
  免费   8篇
  2023年   8篇
  2022年   1篇
  2021年   1篇
  2020年   7篇
  2019年   11篇
  2018年   7篇
  2017年   2篇
  2016年   11篇
  2015年   3篇
  2014年   8篇
  2013年   10篇
  2012年   9篇
  2011年   12篇
  2010年   6篇
  2009年   7篇
  2008年   3篇
  2007年   6篇
  2006年   3篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2002年   2篇
  2001年   3篇
  1999年   2篇
  1998年   1篇
  1991年   1篇
  1990年   1篇
  1983年   1篇
排序方式: 共有129条查询结果,搜索用时 15 毫秒
1.
地理学家的演讲与他们运用文字、图象所作的交流同样值得重视.美国的地理学可以通过下述途径得到加强,即围绕地点、地区和全球联系发展实质性演讲,促进自然地理的发展,恢复地理生态的传统.地理信息系统(geographic information systems)对于完成上述任务,对于改进地理学科以满足不断出现的需要,将是一个非常有用的工具.如果我们能够避免自己拆自己的台,避免不现实的空想,避免玩弄语言技巧,而是坚持在大学里进行高质量的教学,并在教师和从事地理实践工作的人员之间开展学术交流,那么地理学将会变得更加有效.我们有一个前所未有的机会来帮助改进美国的中小学地理教育.  相似文献   
2.
New technologies enable high‐resolution monitoring techniques and the generation of big data and have been heralded as increasing the depth of our understanding of geomorphic phenomena. These technologies, however, also provide us with a convenient entry point into the increasingly constraining political economy of geomorphology. Building on the work of Stuart Lane and of critical physical geographers, this paper traces and examines the multiple roles that new technologies have played in constraining research questions and directing resources. Using the activity sphere framework outlined by David Harvey, the influence of new technologies can be traced around the spheres and their constraining of existing relations within academia and explanation identified.  相似文献   
3.
4.
江苏邳州梁王城遗址西周墓地出土了67例西周人骨,对其性别、年龄、人口寿命、体质类型、身高情况的分析特别是对颅骨形态特征的研究表明,梁王城西周组居民属于蒙古人种,具有中颅型结合高颅、狭颅的特点,同时具有狭额、高眶、阔鼻、正颌的面部特征,并且具有长狭的下颌。梁王城西周组居民的颅型与现代亚洲蒙古人种的东亚类型最为接近;面部特征与东亚类型、北亚类型比较接近;体质形态与河南、陕西、甘肃、青海出土的同时代人骨存在一定差异,但这种差异小于梁王城西周组与梁王城大汶口组、殷墟中小墓III组、滕州前掌大B组之间的差异。  相似文献   
5.
This paper explores the effectiveness of a tutorial-based approach in supporting the development of geography undergraduates’ ethical thinking. It was found that overall the intervention had a statistically significant impact on students’ ethical thinking scores as assessed using a Meta-Ethical Questionnaire. The initiative led to a convergence of scores, having a bigger impact on those who had a relatively low score prior to the intervention. Interestingly, the approach had the biggest impact on students who self-identified as physical geographers. Unlike some previous research, there was little evidence of difference between male and female students.  相似文献   
6.
Summary : The article explores deployment of the Darwinian narrative of the “natural history of humanity” in Russian physical anthropology in the late nineteenth to the early twentieth century. It traces two narratives developed by the leading Russian school of physical anthropology: one narrative advanced a universalist vision of collective scholarly enterprise working toward clarifying the missing links in the a priori accepted developmental evolutionary model. The other constructed a new language that undermined the idea of species/subspecies/races/nations/ as stable, externally bounded, and internally homogeneous units and attempted to rationalize imperial hybridity. The article's main focus is on the latter classificatory narrative, its relational methodology, and the protostructuralist units of comparison that it produced.  相似文献   
7.
In an era of rapid geographical data acquisition, interpretations of remote sensing products are an integral part of many undergraduate geography degree schemes but there are fewer opportunities for collection and processing of primary remote sensing data. Unmanned Aerial Vehicles (UAVs) provide a relatively inexpensive opportunity to introduce the principles and practice of airborne remote sensing into field courses, enabling students to learn about image acquisition, data processing and interpretation of derived products. Two case studies illustrate how a low-cost “DJI Phantom Vision+” UAV can be used by students to acquire images that can be processed using Structure-from-Motion photogrammetry software. Results from a student questionnaire and analysis of assessed student reports showed that using UAVs enhanced student engagement and equipped them with data processing skills. The derivation of bespoke orthophotos and Digital Elevation Models has the potential to provide students with opportunities to gain insight into various remote sensing data quality issues, although additional training is required to maximize this potential. Recognition of the successes and limitations of this teaching intervention provides scope for improving future UAV exercises. UAVs are enabling both a reconstruction of how we measure the Earth’s surface and a reconstruction of how students do fieldwork.  相似文献   
8.
Musculoskeletal stress markers (MSM) have been used to reconstruct activity patterns and labour intensity of past populations. Age and size have been found to correlate with MSM, and these aspects should be considered in activity reconstructions. The aim of this study was to find out the nature and the effects of labour intensity, age and size on MSM. Study material were skeletons (N = 108) of individuals of known age, sex and occupation housed at the Natural History Museum, Finland. MSM were scored for Pectoralis major, Deltoid, Teres major and Biceps brachii. These scores were combined to reflect total activity of an individual. Geometric mean of humeral measurements was used as a size indicator and radial tuberosity size was used as a muscle size indicator. Factors explaining MSM were studied using ANCOVA. This included age, size, muscle size, sex, labour intensity, and their interactions. Age and muscle size were the most significant factors explaining MSM, where muscle attachment areas and MSM grow with advancing age. Muscle attachment areas and skeletal frame size were also found to correlate. Least squares regression parameter estimates were used to study the effects of labour intensity, sex and side on MSM. It was found that in early life scores are higher in heavy labour group, but there is less age‐related increase in these scores. This could mean that bone is unable to respond to heavy and continuous loading with surface structure. Therefore labour intensity cannot be reliably recorded in old individuals. Also age and size (as reflected in muscle attachment area) affect MSM and these aspects should be considered before making assumptions on labour intensity. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
9.
甲基三甲氧基硅烷对砂岩石刻封护性能的实验室研究   总被引:1,自引:0,他引:1  
为了解砂岩石刻用甲基三甲氧基硅烷材料封护处理后的各项性能,选择四川省内风化较严重的摩崖造像区的砂岩作为实验样品,采用浸水、酸雾、盐老化、光老化、循环破坏等方法对材料的憎水性、透气性、耐老化性能进行实验测试。试验表明,砂岩样品用甲基三甲氧基硅烷封护处理后其憎水性、耐老化性都有较大的提高,透气性没有太大的改变,半涂样品经循环破坏处理后,表面出现开裂现象。通过研究表明,甲基三甲氧基硅烷材料处理砂岩后其憎水性和耐老化性都较好,但循环破坏实验提示,甲基三甲氧基硅烷材料处理石刻可能对其表面产生负作用,在石刻保护中应慎重使用。  相似文献   
10.
Ceramic amphorae have been the most popular transport and storage containers for a large variety of liquid and solid products. The amphorae of the present study were used as transport containers for wine from the island of Kos (East Aegean). Therefore, they had to fulfil certain requirements in terms of mechanical strength and toughness but also in terms of standardization of vessel size and shape. An assemblage of amphora fragments from the excavation of ancient Halasarna, an amphora production centre, will be presented. The ceramics were studied by means of their chemical and mineralogical composition and fabric. Furthermore, their material properties were measured and their mechanical performance was simulated in computer models.  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