全文获取类型
收费全文 | 1885篇 |
免费 | 127篇 |
国内免费 | 253篇 |
专业分类
安全科学 | 244篇 |
废物处理 | 17篇 |
环保管理 | 397篇 |
综合类 | 836篇 |
基础理论 | 147篇 |
污染及防治 | 104篇 |
评价与监测 | 78篇 |
社会与环境 | 340篇 |
灾害及防治 | 102篇 |
出版年
2024年 | 6篇 |
2023年 | 20篇 |
2022年 | 41篇 |
2021年 | 64篇 |
2020年 | 43篇 |
2019年 | 42篇 |
2018年 | 56篇 |
2017年 | 74篇 |
2016年 | 70篇 |
2015年 | 90篇 |
2014年 | 67篇 |
2013年 | 154篇 |
2012年 | 127篇 |
2011年 | 154篇 |
2010年 | 105篇 |
2009年 | 104篇 |
2008年 | 83篇 |
2007年 | 153篇 |
2006年 | 117篇 |
2005年 | 86篇 |
2004年 | 80篇 |
2003年 | 73篇 |
2002年 | 75篇 |
2001年 | 42篇 |
2000年 | 61篇 |
1999年 | 46篇 |
1998年 | 31篇 |
1997年 | 27篇 |
1996年 | 21篇 |
1995年 | 22篇 |
1994年 | 32篇 |
1993年 | 11篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 2篇 |
排序方式: 共有2265条查询结果,搜索用时 15 毫秒
971.
Implementation of failure modes and effects analysis in detergent production companies: A case study 下载免费PDF全文
Failure mode and effect analysis (FMEA) is the most important method used by production companies to identify potential risks regarding occupational and health hazards and environmental hazards. This method is also useful in defining preventive actions to reduce the effects of these risks. Detergent production companies continually encounter many occupational and health hazards and environmental hazards, the management and reduction of which requires complex assessment in real‐world applications. This paper presents a framework for application of FMEA for managing and ranking identified risks in detergent production companies. A case study is presented to show the application of an FMEA to investigate the results of its application and the outcomes from the analysis. A risk priority number (RPN) is proposed for each distinct risk. The application of FMEA in the detergent production company resulted in grouping the RPN of the identified risks into four different categories. The main corrective actions, which are determined to reduce the RPNs, are presented in this paper. Improving the RPN of the main risks is observed after executing the corrective actions. 相似文献
972.
论述了冶炼烟气中含硒量特别是气态硒检测的方法,并对有效选用采样仪器,抽气体积,吸收液等关键问题做了具有针对性的分析探讨。 相似文献
973.
Human health is greatly affected by inadequate access to sufficient and safe drinking water, especially in low and middle-income countries. Drinking water governance improvements may be one way to better drinking water quality. Over the past decade, many projects and international organizations have been dedicated to water governance; however, water governance in the drinking water sector is understudied and how to improve water governance remains unclear. We analyze drinking water governance challenges in three countries – Brazil, Ecuador, and Malawi – as perceived by government, service providers, and civil society organizations. A mixed methods approach was used: a clustering model was used for country selection and qualitative semi-structured interviews were used with direct observation in data collection. The clustering model integrated political, economic, social and environmental variables that impact water sector performance, to group countries. Brazil, Ecuador and Malawi were selected with the model so as to represent the diversity of the clusters. This comparative case study is important because similar challenges are identified in the drinking water sectors of each country; while, the countries represent diverse socio-economic and political contexts, and the case selection process provides generalizability to our results. We find that access to safe water could be improved if certain water governance challenges were addressed: coordination and data sharing between ministries that deal with drinking water services; monitoring and enforcement of water quality laws; and sufficient technical capacity to improve administrative and technical management of water services at the local level. From an analysis of our field research, we also developed a conceptual framework that identifies policy levers that could be used to influence governance of drinking water quality on national and sub-national levels, and the relationships between these levers. 相似文献
974.
本文对川南旅游开发的导向、人才与资金准备及产业协调等问题进行了探讨,提出了川南旅游资源地域开发的时空模式,建议加强重点景区的资源保护与开发建设,提倡生态旅游 相似文献
975.
蒸散量测定与估算方法的对比研究 总被引:34,自引:1,他引:33
以涡度相关法的实测资料为标准,对波文比-能量平衡法、空气动力学法、Penman-Monteith模型、Shuttleworth-Wallace模型进行对比研究,并分析了各种方法的精度和灵敏度。结果表明:Penman-Monteith模型和波文比-能量平衡法的精度最高,Shuttleworth-Wallace模型和空气动力学法的精度较差。Penman-Monteith模型的稳定性较好,波文比-能量平衡法受Δe和ΔT观测精度的影响大,风温湿观测高度以及下垫面是否均一对空气动力学法影响较大,Shuttleworth-Wallace模型对各类阻抗较为敏感。 相似文献
976.
977.
复合配方絮凝剂处理炼油厂含油废水的研究 总被引:3,自引:1,他引:2
LKM型絮凝剂具有破乳能力强、水溶性好、使用方便和储存稳定的特点 ,其复合制剂的除油效果更好。现场工业试验证明 :在除油率大致相同的情况下 ,其投加量为聚合氯化铝的 1 2至 1 5,浮渣生成量少 ,易于处置和利用 ,可作为聚合氯化铝的换代产品在含油废水处理中使用。 相似文献
978.
正确处理区域发展与生态安全是西部开发战略的关键。以可持续发展为目标的区域空间结构理论 ,分析了在新一轮科技革命和产业革命的新形势下推动区域发展和区域空间结构演变的决定性因素 ,以及实行效益原则与社会公平原则相统一的必要性 ,从中引出西部大开发中确保生态安全的极端重要性。并就实现区域发展与生态安全的双赢目标所必须建立的能力体系和制度体系提出了建议。 相似文献
979.
Tomoaki Tsutsumi Toshihiko Yanagi Munetomo Nakamura Yoichi Kono Hiroyasu Uchibe Takao Iida Tsuguhide Hori Reiko Nakagawa Kazuhiro Tobiishi Rieko Matsuda Kumiko Sasaki Masatake Toyoda 《Chemosphere》2001,45(8):1129-1137
Total diet study (TDS) samples of 14 food groups from 16 locations in Japan, collected in 1999 and 2000, were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) to estimate the update of daily intake of these contaminants from food. The mean daily intake of toxic equivalency (TEQ) for an adult weighing 50 kg, calculated at non-detected isomer concentrations equal to zero (ND=0), was estimated to be 2.25 pg TEQ/kg b.w./day. When non-detected isomer concentrations are assumed to be equal to half of the limits of detection (ND=1/2 LOD), the mean daily intake was estimated to be 3.22 pg TEQ/kg b.w./day. These values were below the tolerable daily intake (TDI) of 4 pg TEQ/kg b.w. for PCDD/Fs and dioxin-like PCBs set in Japan. In both the estimates, the mean daily intakes were highest from fish and shellfish (76.9% at ND=0 and 53.9% at ND=1/2 LOD of the total TEQs), followed by those from meat and eggs (15.5% at ND=0 and 11.7% at ND=1/2 LOD of the total TEQs). Congener specific data revealed that these total TEQ levels were dominated by 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3′,4,4′,5-PeCB in each case (71.7% at ND=0 and 63.1% at ND=1/2 LOD of the total TEQs). The dioxin-like PCBs (non-ortho and mono-ortho PCBs) accounted for about 50% of these total TEQs. These data will be very useful in the risk assessment of PCDD/Fs and dioxin-like PCBs from food in Japan. 相似文献
980.