全文获取类型
收费全文 | 216篇 |
免费 | 15篇 |
国内免费 | 60篇 |
专业分类
安全科学 | 21篇 |
废物处理 | 7篇 |
环保管理 | 23篇 |
综合类 | 113篇 |
基础理论 | 32篇 |
污染及防治 | 66篇 |
评价与监测 | 2篇 |
社会与环境 | 4篇 |
灾害及防治 | 23篇 |
出版年
2023年 | 3篇 |
2022年 | 14篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 31篇 |
2012年 | 16篇 |
2011年 | 18篇 |
2010年 | 23篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 19篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 1篇 |
排序方式: 共有291条查询结果,搜索用时 15 毫秒
81.
地表水中溶解氧监测及变化规律 总被引:7,自引:0,他引:7
采用碘-淀粉光度法对连云港大浦河水域中溶解氧进行测定,并对其日变化、季节变化和垂直分布及变化规律进行了分析。 相似文献
82.
83.
L T Ou P Nkedi-Kizza J L Cisar G H Snyder 《Journal of environmental science and health. Part. B》1992,27(5):545-564
This study was conducted to determine the degradation rates in turfgrass soil over a 12-month period after a single field application of propoxur and to isolate microorganisms from the soil capable of degrading the insecticide. Soil samples were collected from a turfgrass experimental site near Fort Lauderdale, FL one week before the field application of propoxur, and over a 12-month period after the field application. Mineralization rates in surface (0-15 cm depth) and subsurface (15-30 cm depth) soil samples collected before the field application were low. Mineralization in surface and subsurface samples collected 1, 6 and 8 months after the field application was much higher than for corresponding samples collected before the field application. Mineralization in the subsurface samples collected 12 months after the field application had reverted back to the similar rate for the corresponding sample collected before field application. Half-life values (t1/2) for propoxur showed similar trends to the results of mineralization. After a single application of propoxur, degradation in turfgrass soil was enhanced. Such enhancement lasted less than 12 months for the subsurface, but more than 12 months for the surface. A strain of Arthrobacter sp. capable of degrading propoxur was isolated from the soil. 相似文献
84.
文化是一个社会全部物质文明和精神文明的总和,是具有较强民族性的东西。一方面,语言既是文化的一部分,又是文化的载体;另一方面,文化对语言的发展又起着重要的制约作用。东西方文化在哲学观念、历史背景、生活环境、生活习俗等方面的不同分别影响着汉语和英语的形成、发展及应用,并使得它们在长期的使用中逐渐形成自己的特色。 相似文献
85.
86.
Te-Yao Hsu Shiuh-Young Chang Tu-Jou Wang Chia-Yu Ou Zen-Huang Chen Pei-Hua Hsu 《黑龙江环境通报》2001,21(8):665-667
Beare-Stevenson cutis gyrata syndrome is characterized by craniofacial anomalies, particularly craniosynostosis, ear defects, cutis gyrata, acanthosis nigricans, anogenit anomalies, skin tags, and prominent umbilical stump. The prenatal two- and three-dimensional ultrasonographic findings of this rare condition is reported. The detection was made at 32 weeks of gestation in a woman with polyhydramnios and fetal head anomaly. The ultrasound appearance and postnatal follow‒up are presented. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
87.
Jun Li Yongjiong Ni Yongzhen Peng Guowei Gu Jingen Lu Su Wei Guobiao Cheng Changjin Ou 《Frontiers of Environmental Science & Engineering》2008,2(1):99-102
The objectives of this study were to establish an on-line controlling system for nitrogen and phosphorus removal synchronously of municipal wastewater in a sequencing batch reactor (SBR). The SBR for municipal wastewater treatment was operated in sequences: filling, anaerobic, oxic, anoxic, oxic, settling and discharge. The reactor was equipped with on-line monitoring sensors for dissolved oxygen (DO), oxidation-reduction potential (ORP) and pH. The variation of DO, ORP and pH is relevant to each phase of biological process for nitrogen and phosphorus removal in this SBR. The characteristic points of DO, ORP and pH can be used to judge and control the stages of process that include: phosphate release by the turning points of ORP and pH; nitrification by the ammonia valley of pH and ammonia elbows of DO and ORP; denitrification by the nitrate knee of ORP and nitrate apex of pH; phosphate uptake by the turning point of pH; and residual organic carbon oxidation by the carbon elbows of DO and ORP. The controlling system can operate automatically for nitrogen and phosphorus efficiently removal. 相似文献
88.
89.
白洋淀湿地水质与水生物相关性研究 总被引:5,自引:1,他引:4
水质与水生物间关系是湿地生态学的研究热点,研究成果可为湿地水生态修复提供科学依据.在白洋淀湿地设置14个采样点,选取9个水质因子、4类11个水生物指标,利用冗余分析(RDA)方法对其进行研究.结果表明,白洋淀湿地水质和水生物相关性显著,前两个排序轴水质与水生物的相关系数分别为0.973和0.821,特征值分别是0.862和0.059.DO、NO3--N、SD、TN和TP是影响水生物的主要水质因子,第一排序轴与NO3--N和DO显著正相关;第二排序轴与SD显著正相关,与TN和TP显著负相关.比较可知,NO3--N、DO对浮游动植物影响显著,特征值占主要水质因子总特征值的89%;SD、TN和TP对底栖动物及大型水生植物影响大,特征值占主要水质因子总特征值的94%. 相似文献
90.
Li Xiaoyu Zhang Rusheng Huang Zheng Yao Dong Luo Lei Chen Jingfang Ye Wen Li Lingzhi Xiao Shan Liu Xiaolei Ou Xinhua Sun Biancheng Xu Mingzhong Yang Rengui Zhang Xian 《Food and environmental virology》2022,14(1):30-39
Food and Environmental Virology - In routine surveillance for avian influenza viruses (AIVs) in the environments of live poultry markets (LPMs), certain samples were positive for AIVs type A while... 相似文献