全文获取类型
收费全文 | 383篇 |
免费 | 12篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 17篇 |
废物处理 | 21篇 |
环保管理 | 34篇 |
综合类 | 65篇 |
基础理论 | 57篇 |
环境理论 | 1篇 |
污染及防治 | 90篇 |
评价与监测 | 83篇 |
社会与环境 | 20篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 9篇 |
2022年 | 19篇 |
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 20篇 |
2017年 | 14篇 |
2016年 | 26篇 |
2015年 | 15篇 |
2014年 | 23篇 |
2013年 | 30篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 21篇 |
2009年 | 19篇 |
2008年 | 18篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 7篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 21篇 |
2001年 | 10篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1957年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有399条查询结果,搜索用时 15 毫秒
1.
2.
In this paper, impacts of climate change on wheat development rate and production in the northern China are discussed. The results show that the temperature is a controlling factor of development rate but the precipitation is not. The higher the temperature is. the faster the development and the shorter development period will be. Without consideration to varieties and cropping system, meteorological yield of winter wheat would decrease 170.40, 134.25, 98.70 and 97.20 kg/hm2 in the north China and 13.97, 7.95, 39.60 and 19.80 kg/hm2 in the northwest China compared with that in 1950s, 1960s, 1970s and 1980s, respectively, when the CO2 concentration in the atmosphere is doubled. In drought and semi-drought regions, the spring wheat yield would drop with the temperature rise in and raise with the precipitation increase. The influence of temperature on weight of leaf and stalk is also remarkable. 相似文献
3.
火灾是一种灾害性燃烧现象 ,给人员和财产安全带来极大损失。氯化氢 (HCl)是火灾烟气中阻碍人员逃生的最重要的刺激性气体之一。以典型的小尺度和大尺度实验为例 ,分析了加热程度和通风供氧对常用有机材料起火后释放HCl的影响 ,发现不论小尺度还是大尺度 ,HCl的形成只与燃烧过程有关 ,与氧化过程无关 ,HCl的生成率不随通风情况不同而改变。实验中影响HCl释放的主要因素是热 (辐射加热热流密度或温度 )。当超过CCl键发生断裂的温度后 ,继续升温HCl释放速率不发生改变 ,出现稳定释放阶段。在反映HCl释放过程不同尺度间存在共性 ,因此 ,利用小尺度的结果进行释放规律内在机理的探索是合理的方法 相似文献
4.
Daşdemir I 《Environmental management》2005,35(3):247-257
The purpose this study was to improve operational planning and management of national parks in Turkey to balance conservation use and sustainable management. Souksu National Park (SNP) was chosen as the study area. The data were obtained from interviews of 182 visitor groups (in total, 819 people) and analyzed using correlation, factor, discriminant, and regression analyses. It was found that the most important factors affecting operational planning and management of SNP are (1) travel cost, (2) visitor welfare level, (3) intensity of use, (4) size of visitor group, (5) type of recreational demand. The main source of visitors to SNP is from a zone within a 0–90-km radius. This region comprised 53.85% of total visitors to the park. The capital of Turkey (Ankara) is the most important source of visitors from within this zone. The optimum activity mix in SNP is also determined. Picnicking, viewing the scenery, and nature walks or trekking comprised the main uses of the park. It is anticipated that these findings will help to improve operational planning and sustainable management of the national park and the environment. 相似文献
5.
Tüzün I Bayramoğlu G Yalçin E Başaran G Celik G Arica MY 《Journal of environmental management》2005,77(2):85-92
The microalgae Chlamydomonas reinhardtii was used for the biosorption of Hg(II), Cd(II) and Pb(II) ions. The maximum adsorption of Hg(II) and Cd(II) ions on Chlamydomonas reinhardtii biomass was observed at pH 6.0 and the corresponding value for Pb(II) ions was 5.0. The biosorption of Hg(II), Cd(II) and Pb(II) ions by microalgae biomass increased as the initial concentration of Hg(II), Cd(II) and Pb(II) ions increased in the biosorption medium. The maximum biosorption capacities of microalgae for Hg(II), Cd(II) and Pb(II) ions were 72.2+/-0.67, 42.6+/-0.54 and 96.3+/-0.86 mg/g dry biomass, respectively. The affinity order for algal biomass was Pb(II)>Hg(II)>Cd(II). FT-IR analysis of algal biomass revealed the presence of amino, carboxyl, hydroxyl and carbonyl groups, which were responsible for biosorption of metal ions. Biosorption equilibrium was established in about 60 min and the equilibrium was well described by the Freundlich biosorption isotherms. Temperature change in the range of 5-35 degrees C did not affect the biosorption capacity. The microalgae could be regenerated using 0.1 M HCl, with up to 98% recovery, which allowed the reuse of the biomass in six biosorption-desorption cycles without any considerable loss of biosorption capacity. 相似文献
6.
7.
Onifade Stephen Taiwo Erdoğan Savaş Alagöz Mehmet Bekun Festus Victor 《Environmental science and pollution research international》2021,28(31):41663-41674
Environmental Science and Pollution Research - The quest for improved environmental quality through low-carbon emission has been explored in this study in the wake of the growing call for a... 相似文献
8.
结合实例分析,介绍如何将HAZOP分析方法引入到操作规程的编写过程当中,从而提升操作规程的有效性。 相似文献
9.
磁湖底泥氮释放通量的研究 总被引:1,自引:0,他引:1
本研究通过对磁湖底泥氮释放的特性进行实验室静态模拟实验,测定不同温度对磁湖底泥中氮释放量的影响。结果表明,温度升高时,底泥中NH3-N、TN释放通量增大,NO2-N和NO3-N释放通量减小。磁湖底泥的TN释放通量为-120到-25 mg/m3.d,NH3-N、NO2-N和NO3-N和TN释放通量基本呈负释放,说明磁湖大部分氮元素沉积到底泥中。本研究为探讨磁湖水质的改善提供相关的依据,并为以后关于磁湖的治理研究提供一定参考。 相似文献
10.