全文获取类型
收费全文 | 921篇 |
免费 | 99篇 |
国内免费 | 188篇 |
专业分类
安全科学 | 130篇 |
废物处理 | 17篇 |
环保管理 | 197篇 |
综合类 | 475篇 |
基础理论 | 127篇 |
环境理论 | 6篇 |
污染及防治 | 88篇 |
评价与监测 | 80篇 |
社会与环境 | 63篇 |
灾害及防治 | 25篇 |
出版年
2024年 | 2篇 |
2023年 | 19篇 |
2022年 | 17篇 |
2021年 | 27篇 |
2020年 | 35篇 |
2019年 | 38篇 |
2018年 | 34篇 |
2017年 | 55篇 |
2016年 | 52篇 |
2015年 | 40篇 |
2014年 | 45篇 |
2013年 | 88篇 |
2012年 | 73篇 |
2011年 | 80篇 |
2010年 | 53篇 |
2009年 | 67篇 |
2008年 | 47篇 |
2007年 | 52篇 |
2006年 | 49篇 |
2005年 | 44篇 |
2004年 | 28篇 |
2003年 | 40篇 |
2002年 | 33篇 |
2001年 | 36篇 |
2000年 | 18篇 |
1999年 | 31篇 |
1998年 | 19篇 |
1997年 | 12篇 |
1996年 | 11篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 7篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1208条查询结果,搜索用时 62 毫秒
151.
152.
城市区域光热资源特征 总被引:4,自引:0,他引:4
张一平 《城市环境与城市生态》1999,12(1):40-43
利用昆明城内外辐射、风湿产测资料,分析了昆明地区光温的日变化规律、城内外差异等特征,获得了昆明市有丰富的可利用光热资源的结论。 相似文献
153.
154.
3m直径煤油池火灾火焰特性的数值研究 总被引:1,自引:0,他引:1
为了预测油池火灾的火焰特性,采用CFD模拟技术开展静风状态下3 m直径煤油液池的火灾场景模拟,探讨火焰温度、火焰羽流速度、辐射热通量、燃烧产物质量分数等油池火焰特性参数随高度的变化关系;并结合火焰形态分布,提出一种4区域模型,即将湍流扩散火焰划分为油气混合燃烧区、燃烧火焰区、烟尘区和热烟气区来分析燃烧气流在不同高度的实际物理化学特性。此外,通过经验公式和CFD模拟2种方法分别计算出3 m直径煤油池火灾的火焰高度、火焰表面的辐射通量及热辐射破坏半径,并对计算结果进行比较分析,结果表明:2种方法可互相补充完善,有助于池火灾的热辐射危害性评估。 相似文献
155.
156.
157.
158.
159.
Wendong WANG Qinghai FAN Zixia QIAO Qin YANG Yabo WANG Xiaochang WANG 《Frontiers of Environmental Science & Engineering》2015,9(1):147
The presence of humic acid in drinking water treatment has received significant attention in recent years because of its adverse effects on the removal of many pollutants in coagulation. In this paper, the effects of water quality including pH, turbidity, alkalinity, and hardness on the removal of humic acid were investigated in a UV light hybridized coagulation process. Our results suggested that UV light radiation could effectively improve the removal rate of humic acid in coagulation under both neutral and basic conditions, and the variations of the selected water quality parameters had little adverse effect on the function of UV light. After UV light radiation, the removal rate of the nitro-humic acid (NHA) increased from 20% to 60% in coagulation, and increased further to 75% and 85% for the raw waters with 10.0 NTU kaolin and 100 mg·L-1 hardness, respectively. In addition to NHA, the removal rates of the humic acid extracted from peat coal (PHA) and the humic acid provided by Japan metals and chemicals company (JHA) in coagulation were also improved, both in the range of 80%–90% after undergoing UV light radiation. By changing the radiation location from prior to coagulation to the flocculation process, similar experimental results were obtained. The formation of positive charged sites after UV light radiation was considered to be the primary factor that led to an enhanced removal of the humic acid in coagulation. 相似文献
160.
To reveal the flame-propagation behavior and the thermal-radiation effects during coal-dust explosions, two coal-dust clouds were tested in a semi-enclosed vertical combustion tube. A high-speed video camera and a thermal infrared imaging device were used to record the flame-propagation process and the thermal-radiation effects of the fireball at the combustion-tube outlet. The flame propagated more quickly and with a higher temperature in the more volatile coal-dust cloud. The coal-dust concentration also significantly affected the propagation behavior of the combustion zone. When the coal-dust concentration was increased, the flame-propagation velocity and the fireball temperature increased before decreasing overall. Based on the experimental results, a dynamic model of the thermal radiation was employed to describe the changes in the fireballs quantitatively and to estimate the thermal-radiation effects during coal-dust explosions. 相似文献