全文获取类型
收费全文 | 168篇 |
免费 | 8篇 |
出版年
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 2篇 |
2013年 | 41篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1954年 | 2篇 |
1953年 | 2篇 |
1952年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有176条查询结果,搜索用时 921 毫秒
131.
M.J. Morwood T. Sutikna E.W. Saptomo K.E. Westaway Jatmiko R. Awe Due M.W. Moore Dwi Yani Yuniawati P. Hadi J.-x. Zhao C.S.M. Turney K. Fifield H. Allen R.P. Soejono 《Journal of archaeological science》2008
Song Gupuh, a partially collapsed cave in the Gunung Sewu Limestones of East Java, Indonesia, contains over 16 m of deposits with a faunal sequence spanning some 70 ka. Major changes in the range of animals represented show the impact of climate change and humans. The Terminal Pleistocene and Early Holocene was a period of maximum biodiversity. Human use of Song Gupuh and other cave sites in the region also intensified significantly from ca. 12 ka, together with a new focus on exploitation of small-bodied species (macaque monkeys and molluscs), the first evidence for import of resources from the coast, and use of bone and shell tools. Human activity, especially after the onset of the Neolithic around 2.6 ka, subsequently contributed to a progressive loss of many species from the area, including tapir, elephant, Malayan bear, rhino and tiger, and this extinction process is continuing. We conclude by discussing the biogeographical significance of Song Gupuh in the context of other sites in Java (e.g. Punung, Wajak) and further afield (e.g. Liang Bua). 相似文献
132.
133.
134.
135.
136.
137.
Abstract: This paper examines the case of elephant‐back safaris in Thailand and Botswana; it argues that tourism has extended and deepened neoliberalism by targeting and opening up new frontiers in nature. In essence tourism redesigns and repackages nature for global consumption. Through a cross comparison of the same product (the use of captive/trained elephants) in two very different contexts (Thailand and Botswana) this paper analyses the variations in “actually existing neoliberalisms” ( Brenner and Theodore 2002 ) and demonstrates that the effects are not unremittingly negative ( Castree 2008b ). It also draws out the ways that neoliberalism is challenged and reshaped by context specific processes and so it does not completely displace existing ways of approaching nature. Instead, existing approaches mix with neoliberalism to create new ways of valuing and conserving elephants. 相似文献
138.
139.
140.
W. S. Han M. Lu B. J. McPherson E. H. Keating J. Moore E. Park Z. T. Watson N.‐H. Jung 《Geofluids》2013,13(3):283-297
Geologic carbon capture and storage (CCS) is an option for reducing CO2 emissions, but leakage to the surface is a risk factor. Natural CO2 reservoirs that erupt from abandoned oil and gas holes leak to the surface as spectacular cold geysers in the Colorado Plateau, United States. A better understanding of the mechanisms of CO2‐driven cold‐water geysers will provide valuable insight about the potential modes of leakage from engineered CCS sites. A notable example of a CO2‐driven cold‐water geyser is Crystal Geyser in central Utah. We investigated the fluid mechanics of this regularly erupting geyser by instrumenting its conduit with sensors and measuring pressure and temperature every 20 sec over a period of 17 days. Analyses of these measurements suggest that the timescale of a single‐eruption cycle is composed of four successive eruption types with two recharge periods ranging from 30 to 40 h. Current eruption patterns exhibit a bimodal distribution, but these patterns evolved during past 80 years. The field observation suggests that the geyser's eruptions are regular and predictable and reflect pressure and temperature changes resulting from Joule–Thomson cooling and endothermic CO2 exsolution. The eruption interval between multiple small‐scale eruptions is a direct indicator of the subsequent large‐scale eruption. 相似文献