全文获取类型
| 收费全文 | 108篇 |
| 免费 | 5篇 |
| 国内免费 | 2篇 |
专业分类
| 测绘学 | 15篇 |
| 大气科学 | 5篇 |
| 地球物理 | 22篇 |
| 地质学 | 49篇 |
| 海洋学 | 14篇 |
| 天文学 | 9篇 |
| 自然地理 | 1篇 |
出版年
| 2022年 | 2篇 |
| 2021年 | 4篇 |
| 2020年 | 1篇 |
| 2019年 | 2篇 |
| 2018年 | 10篇 |
| 2017年 | 11篇 |
| 2016年 | 6篇 |
| 2015年 | 1篇 |
| 2014年 | 5篇 |
| 2013年 | 18篇 |
| 2012年 | 3篇 |
| 2011年 | 1篇 |
| 2010年 | 10篇 |
| 2009年 | 11篇 |
| 2008年 | 5篇 |
| 2007年 | 3篇 |
| 2006年 | 5篇 |
| 2005年 | 2篇 |
| 2004年 | 3篇 |
| 2003年 | 1篇 |
| 2002年 | 1篇 |
| 2001年 | 1篇 |
| 2000年 | 2篇 |
| 1993年 | 1篇 |
| 1987年 | 1篇 |
| 1985年 | 1篇 |
| 1982年 | 1篇 |
| 1978年 | 1篇 |
| 1975年 | 1篇 |
| 1974年 | 1篇 |
排序方式： 共有115条查询结果，搜索用时 687 毫秒
61.
62.
63.
64.
Sadeghi Maedeh Jandaghi Alaee Farshid Akbarzadeh Bengar Habib Jafari Abouzar 《Bulletin of Earthquake Engineering》2022,20(11):6075-6107
Bulletin of Earthquake Engineering - Although self-centering rocking walls have shown acceptable performance in decreasing downtime, repair cost, and continuous serviceability, their energy... 相似文献
65.
66.
Runoff and sediment yield modeling using SWAT model: case of Wadi Hatab basin,central Tunisia 总被引：1，自引：0，他引：1
This study presents an application of the model Soil and Water Assessment Tool (SWAT) to simulate daily and monthly water flow and sediment fluxes in the Wadi Hatab watershed (2200 km2) located in central Tunisia. The study basin is characterized by a significant climatic contrast, abrupt topography, and soil fragility, resulting thereby in flash floods and important water erosion rates. This alarming situation requires urgent interventions in order to preserve water and soil resources, implying the need for a decision tool for proper integrated management of the watershed. The model was calibrated and validated based on a comparison of simulated and observed flow rates at the basin outlet (hydrometric station Khanguet Zazia), during the periods 1987–1988 and 1989–1990, respectively. The comparison was based not only on visual inspection of the agreement between observed and simulated time series, but also on statistical parameters. Indeed, for the daily time step application, the Nash—Sutcliffe efficiency (NSE) values were 0.52 and 0.61, and the coefficient of determination (R2) was 0.54 and 0.61 for calibration and validation, respectively. As for the monthly time-step application, the obtained NSE values were 0.67 and 0.89 while R2 values were 0.83 and 0.87 for calibration and validation, respectively. This clearly shows the reasonably good agreement between simulated and observed flow rates. In terms of erosion, the model gave sediment yield values ??of 1.15 and 5.37 t/ha/year during the periods of calibration and validation, respectively. 相似文献
67.
68.
The water and bed-sediment pollution status of the Padma River was determined by analysis of representative samples for selected
metals and ions. Water and bed-sediment samples were collected at a T-dam, Rajshahi, Bangladesh, for 7 months. Water and silt-metal
content analysis was performed using atomic absorption spectrophotometry or other analytical methods. The data showed the
variation of the metal ion-levels in water as follows: Ca 17.11–48.37 ppm, Na 17.51–20.09 ppm, K 1.00–3.60 ppm, Cr 2.80–7.00 ppm,
and SO4 4.17–5.48 ppm; in bed sediment, the levels were Cr 35–1050 ppm and Pb 12–48 ppm. The occurrence of Na, K and Ca was in the
normal range (US EPA permissible limit), but the levels of Cr in water were much higher than the permissible limit. The SO4 ion content was well below the pollution level. The concentration of Pb in the bed sediment was within the permissible limit
for the standard International Atomic Energy Agency (IAEA) Soil-5a, but the concentration of Cr in the bed sediment was significantly
higher than the permissible limit for the standard IAEA Soil-5a. Thus the Padma river water was polluted with Cr. The occurrence
of some ions showed a monthly variation.
Received: 19 August 1999 · Accepted: 12 October 1999 相似文献
69.
70.