全文获取类型
收费全文 | 1062篇 |
免费 | 45篇 |
国内免费 | 334篇 |
专业分类
安全科学 | 61篇 |
废物处理 | 64篇 |
环保管理 | 88篇 |
综合类 | 536篇 |
基础理论 | 190篇 |
污染及防治 | 360篇 |
评价与监测 | 48篇 |
社会与环境 | 32篇 |
灾害及防治 | 62篇 |
出版年
2023年 | 17篇 |
2022年 | 59篇 |
2021年 | 43篇 |
2020年 | 27篇 |
2019年 | 30篇 |
2018年 | 40篇 |
2017年 | 42篇 |
2016年 | 41篇 |
2015年 | 59篇 |
2014年 | 80篇 |
2013年 | 101篇 |
2012年 | 96篇 |
2011年 | 93篇 |
2010年 | 77篇 |
2009年 | 65篇 |
2008年 | 79篇 |
2007年 | 69篇 |
2006年 | 75篇 |
2005年 | 47篇 |
2004年 | 31篇 |
2003年 | 32篇 |
2002年 | 32篇 |
2001年 | 29篇 |
2000年 | 21篇 |
1999年 | 20篇 |
1998年 | 22篇 |
1997年 | 22篇 |
1996年 | 16篇 |
1995年 | 14篇 |
1994年 | 11篇 |
1993年 | 15篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有1441条查询结果,搜索用时 15 毫秒
461.
Su Wild River 《Local Environment》2013,18(6):719-732
Abstract This paper presents the results of a national project investigating Australian local government (LG) attempts to deliver beneficial environmental outcomes. It briefly describes the extensive environmental planning, management and protection roles played by Australian LGs. It notes that these roles are poorly documented within the academic literature, and makes a case for fundamental research to better understand LGs and their work from the inside. It describes this project's use of grounded theory methods in gathering and analysing 34 case studies of Australian LG environmental initiatives. The inside perspectives represented by the papers show that Australian LG environmental work:
-
extends beyond its statutory requirements;
-
is novel and creative;
-
endures by balancing ecological, social and economic values;
-
demonstrates different patterns depending on its planning, management or protection focus; and
-
usually involves environmental strategists with long-term, passionate commitments to local environmental values.
462.
463.
土壤重金属污染与食品安全 总被引:2,自引:0,他引:2
<正>人们食用的食品主要来源于农产品,农产品质量安全是影响食品安全的首要因素。近几年来,食品安全成了主宰人们日常生活的重要话题。农产品质量安全问题也就成为了人们关注的焦点之一。而农产品的质量与 相似文献
464.
城市脱水污泥常见的处置方式是焚烧、燃烧发电、堆肥后土地化利用和填埋等。无论采用哪种无害化、资源化处置方法,输送环节都是必不可少的。城市污泥管道输送技术是以管道输送设备为核心,融合城市污泥的预处理和处置工艺的集成化系统。通过对城市污泥的流变特性和输送特性实验测试,其流变方程符合幂定律关系式;通过环管实验拟合出了污泥在管道中的阻力损失与输送距离和输送流量之间的关系,经验证,其理论计算和实际测定基本相符,证明管道输送方式能够成功地应用于城市污泥的远距离输送,为城市污泥管道输送系统的优化设计提供了理论依据。 相似文献
465.
Pablo del Río Javier Carrillo-Hermosilla Totti Könnölä Carlos García Suárez 《Mitigation and Adaptation Strategies for Global Change》2008,13(8):863-885
This paper empirically shows how the uncertainty associated to the absence of a mitigation regime which follows the United
Nations Framework Convention on Climate Change Kyoto Protocol (UN FCCC Kyoto Protocol) is affecting investments in abatement
activities in the EU electricity sector and, thus, future emissions levels. Based on a survey of EU electric utilities, it
identifies the most likely post-Kyoto scenarios considered by them and how they are coping with such uncertainty in their
investment decisions. It is found that firms react differently to such uncertainty and adopt different strategies to cope
with it, diversifying their emissions control activities. Although most companies foresee post-Kyoto compliance regimes with
emissions trading systems, they differ in their perceptions of the form that a post-Kyoto regime could take and are, thus,
positioning differently to face such regime. The particular features of each company and the country where they operate affect
their perception of the uncertainties, their position regarding a possible post-Kyoto regime and their inclination to carry
out mitigation activities. Complying with Kyoto (and, eventually, post-Kyoto) targets significantly influences the investment
decisions of European electricity companies. Uncertainty about a post-Kyoto regime may already be affecting investments in
mitigation activities in the electricity sector. Therefore, significant progress has to be made in the definition of a post-Kyoto
regime. It is urgent to define and agree internationally the emissions reduction objectives and the mitigation instruments
that will be accepted for compliance, ensuring continuity of the international emissions trading system foreseen in the Kyoto
Protocol.
相似文献
Pablo del RíoEmail: |
466.
Measurement of flow speed in the channels of novel threadlike structures on the surfaces of mammalian organs 总被引:1,自引:0,他引:1
There have been several reports on novel threadlike structures (NTSs) on the surfaces of the internal organs of rats and rabbits
since their first observation by Bonghan Kim in 1963. To confirm this novel circulatory function, it is necessary to observe
the flow of liquid through the NTS as well as the structurally corroborating channels in the NTS. In this article, we report
on the measurement of the flow speed of Alcian blue solution in the NTSs on the organ surfaces of rabbits, and we present
electron microscopic images depicting the cribrous cross-section with channels. The speed was measured as 0.3 ± 0.1 mm/s,
and the flow distance was up to 12 cm. The flow was unidirectional, and the phase contrast microscopic images showed that
the NTSs were strongly stained with Alcian blue. The ultrastructure of the NTSs revealed by cryo-scanning electron microscopy
and high-voltage electron microscopy showed that (1) there were cell-like bodies and globular clumps of matter inside the
sinus of the channel with thin strands of segregated zones which is a microscopic evidence of the liquid flow, (2) the sinuses
have wall structures surrounded with extracellular matrices of collagenous fibers, and (3) there exists a cribriform structure
of sinuses. To understand the mechanism for the circulation, a quantitative analysis of the flow speed has been undertaken
applying a simplified windkessel model. In this analysis, it was shown that the liquid flow through the NTSs could be due
to peristaltic motion of the NTS itself.
Baeckkyoung Sung and Min Su Kim contributed equally to this work. 相似文献
467.
介绍了内浮顶罐防腐作业时发生的爆炸事故,进行了故障树分析,结合故障树最小割集对基本事件进行了深入分析,表明非防爆喷漆的电火花是这次事故的点火源,提出了防止类似事故的措施。 相似文献
468.
Yang Su Ye Qi Zhouyan Xiao Yu Wei 《Frontiers of Environmental Science & Engineering in China》2009,3(1):75-90
With the development of rural pollution, its characteristic and institutional factor should be studied for pollution control
through economics and sociology. Based on the data gathered from investigations by several government sectors, rural environmental
pollution can be divided into two types by its sources: internal source type and external source type. The internal source
type is the main component of rural pollution at present, which can be further divided into three types. Research shows that
the contributing institutional factors of rural pollution issues and the effectiveness of environmental management system
over rural pollution can be summarized as distinctiveness. In essence, the rural pollution issue results from the dualism
of rural and urban areas’ inadaptability to rural modernization. In detail, the contributing factors can be summed up on three
institutional levels. There are obvious loopholes in rural environmental management system which, in the meantime, is incapable
and inadaptable to rural pollution control. There exist similar questions in the related public service system, which are
intensified by inappropriate reform which brought about incompatible incentive in the recent years. However, in the eleventh
five-year plan period, there are advantageous trends in the three institutional levels.
Main data sources in this paper: ➀ the surveys on TVEs (township and village enterprises) conducted by Township Enterprise
Bureau of Ministry of Agriculture of China in 1997 and 2002; ➁ the partial survey on rural environmental conditions by EPA
(environmental protection administration) of Zhejiang Province in 2002; ➂ the survey on the pollution of IPLFs (livestock
and poultry farms) in 23 provinces, municipalities, and directly administered cities by the State Environmental Protection
Administration of China in 2002; ➃ the research report on Mechanism of Investment and Financing for Environmental Protection
by China Council for International Environment and Development Cooperation in 2003; ➄ the third investigation on national
hygiene service in 2003; ➅ the regular monitoring of safe quality of agricultural products by the Ministry of Agriculture
of China in 2005; ➆ the investigation arranged by the Ministry of Health which finished in 2007 and showed the total situation
of rural environmental health and drinking water security of the whole country. 相似文献
469.
论民国初年我国的政府救灾行政系统 总被引:3,自引:1,他引:2
作为国家行政要务的救灾,民国初年中央政府救灾机关是内务部,内务部的权力职掌有一个变化的过程;虽然其名义上作为中央一级专门救灾机构,但由于机构初设.经验不足,再加上其他诸多因素的限制,无论是部务还是权限与其他部门如财政部,农商部等都颇有纠缠.至于地方政府救灾机构,作为地方政府组织机构的一部分,虽属专管,但有兼管之嫌.一些专门的赈济机构,只不过有时囡灾于公署内暂设,事毕即行撤消.当时除了政府救灾机构外,还存在着具有亚政府色彩社会救灾力量.内务部与地方救灾系统之隶属关系相对自由,并从上到下形成了一个错综复杂的网络格局.总体而论,民国初年的救灾机构从中央到地方都比清末进一步完善,其业务范围也逐渐趋于稳定,但由于中央政权极不稳定,内阁更替频繁,致使中央和地方国家机构撤设变化较多,从而引起救灾机构的相形混乱. 相似文献
470.
文章介绍了湿法制备高铁酸钾的工艺,研究了次氯酸盐浓度、氧化反应温度、铁盐原料选择、洗涤所用溶剂种类等对高铁酸钾纯度和产率的影响。实验表明在制备次氯酸盐溶液时用冰水浴反应温度控制为20℃,选用37.5%的KOH溶液,可制得ClO-质量分数为123.5 g/L的饱和次氯酸钾溶液。实验还表明制备高铁酸钾的最佳反应时间为45 min,硝酸铁投加量为化学计量的80%时,可得到纯度为80%~90%、产率为71%的高铁酸钾固体产物。通过实验提出在0℃饱和的氢氧化钾溶液中不断搅拌,高铁酸钾晶体可以充分析出。 相似文献