全文获取类型
收费全文 | 1289篇 |
免费 | 109篇 |
国内免费 | 280篇 |
专业分类
安全科学 | 100篇 |
废物处理 | 93篇 |
环保管理 | 103篇 |
综合类 | 614篇 |
基础理论 | 248篇 |
污染及防治 | 214篇 |
评价与监测 | 271篇 |
社会与环境 | 23篇 |
灾害及防治 | 12篇 |
出版年
2024年 | 9篇 |
2023年 | 11篇 |
2022年 | 27篇 |
2021年 | 31篇 |
2020年 | 33篇 |
2019年 | 44篇 |
2018年 | 35篇 |
2017年 | 40篇 |
2016年 | 72篇 |
2015年 | 68篇 |
2014年 | 71篇 |
2013年 | 159篇 |
2012年 | 104篇 |
2011年 | 133篇 |
2010年 | 85篇 |
2009年 | 85篇 |
2008年 | 88篇 |
2007年 | 90篇 |
2006年 | 87篇 |
2005年 | 59篇 |
2004年 | 58篇 |
2003年 | 58篇 |
2002年 | 39篇 |
2001年 | 29篇 |
2000年 | 30篇 |
1999年 | 22篇 |
1998年 | 29篇 |
1997年 | 25篇 |
1996年 | 20篇 |
1995年 | 17篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有1678条查询结果,搜索用时 562 毫秒
201.
202.
Mercury(Hg), mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines(CPMs) was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry(ICP-MS). The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar(2.5%–30.9%), the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower(0.037%). By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives(FAO/WHO) safety guideline, the average daily intake dose(ADD) of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs. 相似文献
203.
The radioactivity of uranium in radioactive coal bottom ash(CBA) may be a potential danger to the ambient environment and human health. Concerning the limited research on the distribution and mode of occurrence of uranium in CBA, we herein report our investigations into this topic using a number of techniques including a five-step Tessier sequential extraction, hydrogen fluoride(HF) leaching, Siroquant(Rietveld) quantification, magnetic separation, and electron probe microanalysis(EPMA). The Tessier sequential extraction showed that the uranium in the residual and Fe–Mn oxide fractions was dominant(59.1%and 34.9%, respectively). The former was mainly incorporated into aluminosilicates,retained with glass and cristobalite, whereas the latter was especially enriched in the magnetic fraction, of which about 50% was present with magnetite(Fe_3O_4) and the rest in other iron oxides. In addition, the uranium in the magnetic fraction was 2.6 times that in the non-magnetic fraction. The experimental findings in this work may be important for establishing an effective strategy to reduce radioactivity from CBA for the protection of our local environment. 相似文献
204.
205.
我国已颁布了56个重点行业的清洁生产标准,从生产工艺与设备要求及资源能源利用指标等6个方面规定了清洁生产考核的定量或定性指标要求.本文针对尚无清洁生产标准可供参考的陕西省从石煤中提取V<,2>O<,5>的生产企业,从生产工艺及设备的角度出发,按照石煤提钒的工艺流程逐项对生产工艺以及其中的焙烧设备进行清洁性比对,最终得出... 相似文献
206.
对某芳烃抽提装置建设项目中存在的主要职业病危害因素进行了分析,评价其职业病危害控制效果,提出建议措施。 相似文献
207.
208.
209.
作物和土壤中DEHP测定的前处理 总被引:2,自引:0,他引:2
介绍农田土壤和农作物样品中微量DEHP测定的前处理方法。该法选用三氯甲烷为抽提液,加入吸水剂进行革取、抽提和浓缩。与北京、丹麦和美国等测试方法相比较,革取时间为0.5—0.7h,缩短了2—11h;溶剂用量为75—90ml,节省溶剂110—1200ml;操作简便、分离效果好;样品中DEHP的回收率除棉花籽实外,其余均达90%左右,变异系数约土3%。该法适宜在酞酸酯监测中推广应用。 相似文献
210.