收费全文 | 16786篇 |
免费 | 187篇 |
国内免费 | 145篇 |
安全科学 | 474篇 |
废物处理 | 652篇 |
环保管理 | 2442篇 |
综合类 | 2603篇 |
基础理论 | 4568篇 |
环境理论 | 5篇 |
污染及防治 | 4375篇 |
评价与监测 | 1035篇 |
社会与环境 | 857篇 |
灾害及防治 | 107篇 |
2022年 | 115篇 |
2021年 | 135篇 |
2020年 | 109篇 |
2019年 | 156篇 |
2018年 | 231篇 |
2017年 | 235篇 |
2016年 | 375篇 |
2015年 | 255篇 |
2014年 | 375篇 |
2013年 | 1307篇 |
2012年 | 456篇 |
2011年 | 661篇 |
2010年 | 564篇 |
2009年 | 542篇 |
2008年 | 710篇 |
2007年 | 729篇 |
2006年 | 680篇 |
2005年 | 524篇 |
2004年 | 602篇 |
2003年 | 534篇 |
2002年 | 506篇 |
2001年 | 710篇 |
2000年 | 477篇 |
1999年 | 288篇 |
1998年 | 252篇 |
1997年 | 223篇 |
1996年 | 232篇 |
1995年 | 249篇 |
1994年 | 273篇 |
1993年 | 222篇 |
1992年 | 248篇 |
1991年 | 227篇 |
1990年 | 257篇 |
1989年 | 240篇 |
1988年 | 195篇 |
1987年 | 174篇 |
1986年 | 160篇 |
1985年 | 167篇 |
1984年 | 195篇 |
1983年 | 181篇 |
1982年 | 186篇 |
1981年 | 182篇 |
1980年 | 139篇 |
1979年 | 154篇 |
1978年 | 131篇 |
1977年 | 119篇 |
1975年 | 118篇 |
1974年 | 115篇 |
1973年 | 111篇 |
1972年 | 133篇 |
The fire was generated using an array of 25 liquid propane-fuelled burners. This provided a luminous fire that engulfed 25% of the tank surface on one side. The intent of these tests was to model a severe partially engulfing fire situation.
The paper presents data on the tank wall and lading temperatures and tank internal pressure. In the first test the wind reduced the fire heating and resulted in a late failure of the tank at 46 min. This tank failed catastrophically with a powerful boiling liquid expanding vapour explosion (BLEVE). In the other test, the fire heating was very severe and steady and this tank failed very quickly in 8 min as a finite rupture with massive two-phase jet release. The reasons for these different outcomes are discussed. The different failures provide a range of realistic outcomes for the subject tank and fire condition. 相似文献
In North America thermal protection is used to protect dangerous goods rail tank-cars from accidental fire impingement. They are designed so that a tank-car will not rupture for 100 min in a defined engulfing fire, or 30 min in a defined torching fire. One common system includes a 13 mm blanket of high-temperature ceramic fibre thermal insulation covered with a 3 mm steel jacket. Recent inspections have shown that some tanks have significant defects in these thermal protection systems. This work was done to establish what levels of defect are acceptable from a safety standpoint.
The tests were conducted using 1890 l (500 US gallon) ASME code propane pressure vessels (commonly called tanks in the propane industry). The defects tested covered 8% and 15% of the tank surface. The tanks were 25% engulfed in a fire that simulated a hydrocarbon pool fire with an effective blackbody temperature of 870 °C.
The fire testing showed that even relatively small defects can result in tank rupture if the defect area is engulfed in a severe fire, and the defect area is not wetted by liquid from the inside. A wall failure prediction technique based on uniaxial high-temperature stress rupture test data has been developed and agrees well with the observed failure times. 相似文献