全文获取类型
收费全文 | 317篇 |
免费 | 28篇 |
国内免费 | 78篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 3篇 |
环保管理 | 30篇 |
综合类 | 150篇 |
基础理论 | 113篇 |
污染及防治 | 15篇 |
评价与监测 | 29篇 |
社会与环境 | 24篇 |
灾害及防治 | 33篇 |
出版年
2024年 | 2篇 |
2023年 | 17篇 |
2022年 | 15篇 |
2021年 | 12篇 |
2020年 | 11篇 |
2019年 | 18篇 |
2018年 | 16篇 |
2017年 | 8篇 |
2016年 | 27篇 |
2015年 | 16篇 |
2014年 | 11篇 |
2013年 | 29篇 |
2012年 | 16篇 |
2011年 | 22篇 |
2010年 | 29篇 |
2009年 | 20篇 |
2008年 | 13篇 |
2007年 | 20篇 |
2006年 | 21篇 |
2005年 | 19篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有423条查询结果,搜索用时 156 毫秒
421.
Banerjee B Aggarwal PK Pathak H Singh AK Chaudhary A 《Environmental monitoring and assessment》2006,119(1-3):173-189
Rice-wheat cropping systems of the Indo-Gangetic plains (IGP) occupying 12 million ha of productive land are important for the food security of South Asia. There are, however, concerns that yield and factor productivity trends in these systems are declining/stagnating in recent years. Decrease in soil organic carbon is often suggested as a reason for such trends. A field experiment was conducted to study the soil organic carbon (SOC) and soil microbial biomass carbon (MBC) dynamics in the rice-wheat systems. Use of organic amendments and puddling of soil before rice transplanting increased SOC and MBC contents. Microbial biomass carbon showed a seasonal pattern. It was low initially, reached its peak during the flowering stages in both rice and wheat and declined thereafter. Microbial biomass carbon was linearly related to SOC in both rice and wheat indicating that SOC could be used as a proxy for MBC. 相似文献
422.
Since the onset of the COVID-19 pandemic, global virtual teams (GVTs) have become increasingly important. Drawing on conservation of resources theory and self-regulation theory, we examined the mechanism and process underlying individuals' performance in GVTs in this specific situation. We posit that the local severity of the pandemic has a negative effect on individuals' performance in GVTs and that self-regulation functions as a coping mechanism in times of pandemic-related ambient stress, reducing its negative effect on performance. We suggest that three cultural value orientations, that is, uncertainty avoidance, collectivism, and long-term orientation, explain different levels of self-regulation, which in turn moderates the relationship between the local severity of the pandemic and individual performance in GVTs. Based on a sample of 2727 individuals from 31 countries participating in an international business consulting project during the early stage of the unfolding pandemic, we show that (a) the local severity of the pandemic had a negative effect on individuals' performance, (b) the negative effect of the pandemic on performance is weaker for individuals with high self-regulation, and (c) uncertainty avoidance and long-term orientation are positively associated with self-regulation, which mediates the moderating relationship between the cultural value orientations and the relationship between the COVID-19 pandemic and individual performance in GVTs. 相似文献
423.
基于2010—2016年上海城区近地面大气臭氧(O3)的连续在线观测数据,研究了上海城区O3长时间序列变化规律和污染特征.结果表明,近7年来上海城区O3污染逐渐凸显,但总体以轻度污染为主,7—8月高温炎热季节以中度污染居多.城区O3-8 h(臭氧日最大8 h滑动平均)年均增速为3.81 μg·m-3·a-1,99%和95%分位值增速较快,分别为6.65和4.94 μg·m-3·a-1;25%、50%和75%分位值的增速在3.06~4.45 μg·m-3·a-1之间.春季O3浓度均值较高,年际变化小;夏季极值较高,且污染超标情况最为突出;秋季O3浓度次于春、夏季,冬季最低;夏、秋和冬季O3浓度总体呈上升态势.O3日变化呈"单峰型",最大值出现在13:00左右,且峰值逐年增加,污染持续时间变长,最小值出现在早晨7:00.城区O3"周末效应"逐渐减弱.基于KZ过滤器方法的数据分析结果表明,上海城区O3-8 h长期变化主要受O3-BF(O3-8 h的基准组分)影响;O3-SF(O3-8 h的天气影响组分)在5—9月对O3-8 h影响较大,其范围为-98.85~139.60 μg·m-3. 相似文献