全文获取类型
收费全文 | 325篇 |
免费 | 26篇 |
国内免费 | 93篇 |
专业分类
安全科学 | 33篇 |
废物处理 | 11篇 |
环保管理 | 30篇 |
综合类 | 191篇 |
基础理论 | 42篇 |
污染及防治 | 77篇 |
评价与监测 | 30篇 |
社会与环境 | 20篇 |
灾害及防治 | 10篇 |
出版年
2024年 | 4篇 |
2023年 | 9篇 |
2022年 | 18篇 |
2021年 | 23篇 |
2020年 | 18篇 |
2019年 | 12篇 |
2018年 | 15篇 |
2017年 | 16篇 |
2016年 | 22篇 |
2015年 | 29篇 |
2014年 | 28篇 |
2013年 | 34篇 |
2012年 | 28篇 |
2011年 | 31篇 |
2010年 | 25篇 |
2009年 | 20篇 |
2008年 | 18篇 |
2007年 | 20篇 |
2006年 | 18篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 10篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
排序方式: 共有444条查询结果,搜索用时 281 毫秒
141.
142.
143.
144.
不同颗粒龄的好氧颗粒污泥性能的研究 总被引:6,自引:3,他引:3
在SBR反应器中,分别以絮状活性污泥培养的好氧颗粒污泥和直接接种的已稳定运行1 a的好氧颗粒污泥为对象,对2种颗粒龄不同的颗粒污泥的形态、理化特性、对有机物降解能力以及微生物活性进行了比较研究.结果表明,小颗粒龄好氧颗粒的平均湿密度、污泥的比重和表示物理强度的完整系数(IC)分别为1.066 g.cm-3、1.013 g.cm-3和98.7%,各指标均高于大颗粒龄好氧颗粒的1.026 g.cm-3、1.010 g.cm-3和98.4%,两者的平均粒径分别为1.9 mm和2.2 mm.小颗粒龄好氧颗粒和大颗粒龄好氧颗粒的沉降速度分别为0.005~0.032 m.s-1和0.003~0.028 m.s-1,前者的SVI较低,且两体系中好氧颗粒的沉降速度均随粒径的增大而增大.两者对COD、NH4+-N的去除率都保持在90%以上和85%左右,从出水COD浓度、NH4+-N浓度和周期试验来看,小颗粒龄好氧颗粒对COD、NH4+-N的去除效果更好,两者对TP的去除率分别维持在40%~90%和32%~85%,但两者对TN的去除效果相差不大,去除率都在80%左右.同时,小颗粒龄好氧颗粒的异养菌比耗氧速率(SOURH)、亚硝酸菌比耗氧速率(SOURNH4)、硝酸菌比耗氧速率(SOURNO2)分别为26.4、14.8和11.2 mg.(h.g)-1,均大于大颗粒龄好氧颗粒的25.2、14.4和8.4 mg.(h.g)-1.综上所述,好氧颗粒污泥由于颗粒龄的不同会具有明显不同的理化性质,颗粒龄小的好氧颗粒具有更好的有机物降解能力、更高的微生物活性和更好的稳定性. 相似文献
145.
Abstract It is difficult to realize the transformation from traditional economy industrial system to circular economy industrial system. Regarding primary raw materials as the indicators, the industrial system has been specified according to the divergence among the indicators and the circular utilization modes. In comparison with the association among industrial systems, the relationship among industrial sub-systems is named as industrial cross-linking in this paper. The industrial system which could completely utilize and recycle the indicators should be increased and strengthened, and the circular economy industrial system with complete industrial association and industrial cross-linking should also be constructed. Taking the development of circular agricultural system basing on the traditional agricultural system as an example, the traditional agricultural products are regarded as the indicators which have been divided into foodstuff and crop straws which are used to produce food and articles for use, like fertilizer, energy and papers etc. The way to construct the circular agricultural industrial system is to increase the industrial systems that could utilize the products generated from crop straws, feces and other castoffs and transform the wastewater and other trucks into environmental friendly products. It has also been pointed out that the construction of circular economy industrial system is conducive to the foundation of circular industrial economics and the establishment of the construction layout of circular economy and the application schemes. Suggestions to the theoretical and practical work of the next step have also been brought forward in this paper. 相似文献
147.
Plant indicator status and implications for natural disaster management in both developed communities and indigenous communities
下载免费PDF全文
![点击此处可从《Natural resources forum》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kyoo‐Man Ha 《Natural resources forum》2018,42(1):32-41
Only a few rigorous studies have attempted to focus on the topic of plant indicators in relation to natural disasters, although recently an increasing number of people have realized its significance. In an effort to aid disaster management, this article studied and aimed to improve the status of plant indicators in predicting or signaling natural disasters. Using a qualitative content analysis, the plant indicators’ uncertain status and certain status are systematically compared using specific plants, developed community efforts, indigenous community traditions, and characteristics of natural disaster management. A key tenet is that all stakeholders must change plant indicators’ uncertain status to certain status by comprehensively elaborating on the integration between developed communities and indigenous communities, plant indicators as a research agenda, the inclusion of plant indicators in disaster management policy and local plans, and education and training. 相似文献
148.
Advancement of modern agricultural biotechnology has brought various potential benefits to humankind, but at the same time ethical concerns regarding some applications such as genetically modified foods (GMF) have been raised among the public. Several questions are being posed; should they utilize such applications to improve quality of their life, or should they refrain in order to save themselves from any associated risk? What are the ethical principles that can be applied to assess these applications? By using GMF as a case study, this paper discusses possible answers to these questions from Islamic perspective. Such answers are based on the understanding of the Islamic concept of maslahah (benefit) and mafsadah (harm) as well as the Islamic principles of priority. There is no specific GMF that has been declared as unlawful by Muslim scholars thus far. Nevertheless, they generally state that any GMF that contains unlawful substance is prohibited in Islam. Such statement can be understood since Islam puts highest priority to preserve shari’ah (Islamic law) which prescribes the lawful and unlawful things in human life. Priorities have also been given to preserve human health and environment therefore any GMF that may inflict harm on both entities is also considered as unlawful. 相似文献
149.
Hong-Sheng Wang Suthipong Sthiannopkao Zhuo-Jia Chen Yu-Bon Man Jun Du Guang-Hua Xing Kyoung-Woong Kim Mohamed Salleh Mohamed Yasin Jamal Hisham Hashim Ming-Hung Wong 《Environmental geochemistry and health》2013,35(6):745-755
To assess arsenic contaminations and its possible adverse health effects, food samples were collected from Kandal, Kratie and Kampong Cham in Cambodia. The highest and the lowest concentrations were observed in fish (mean 2,832 ng g?1, ww) collected from Kandal province and cattle stomach (1.86 ± 1.10 ng g?1, ww) collected from Kratie, respectively. The daily intake of arsenic via food consumption was 604, 9.70 and 136 μg day?1 in Kandal, Kratie and Kampong Cham, respectively. The arsenic dietary intake in Kandal ranked No. 1 among all the 17 compared countries or regions. Fish consumption contributed the greatest proportion of total arsenic daily intake in Kandal (about 63.0 %) and Kampong Cham (about 69.8 %). It is revealed to be a much more important exposure pathway than drinking water for residents in Kampong Cham. The results of risk assessment suggested that the residents in Cambodia, particularly for people in Kandal province, suffer high public health risks due to consuming arsenic-contaminated food. 相似文献
150.
Kim Kyeong Ho Bae Min A. Lee Man Sig Park Hung-Suck Baek Jae Ho 《Journal of Material Cycles and Waste Management》2021,23(1):121-129
Journal of Material Cycles and Waste Management - Organic binders that are used in sand casting emit high amounts of hazardous pollutants and volatile organic compounds during the casting process.... 相似文献