全文获取类型
收费全文 | 868篇 |
免费 | 124篇 |
国内免费 | 419篇 |
专业分类
安全科学 | 148篇 |
废物处理 | 8篇 |
环保管理 | 65篇 |
综合类 | 567篇 |
基础理论 | 310篇 |
污染及防治 | 197篇 |
评价与监测 | 65篇 |
社会与环境 | 37篇 |
灾害及防治 | 14篇 |
出版年
2024年 | 5篇 |
2023年 | 22篇 |
2022年 | 41篇 |
2021年 | 40篇 |
2020年 | 46篇 |
2019年 | 49篇 |
2018年 | 57篇 |
2017年 | 80篇 |
2016年 | 74篇 |
2015年 | 71篇 |
2014年 | 55篇 |
2013年 | 151篇 |
2012年 | 98篇 |
2011年 | 112篇 |
2010年 | 57篇 |
2009年 | 54篇 |
2008年 | 48篇 |
2007年 | 56篇 |
2006年 | 48篇 |
2005年 | 32篇 |
2004年 | 24篇 |
2003年 | 27篇 |
2002年 | 31篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 16篇 |
1998年 | 14篇 |
1997年 | 11篇 |
1996年 | 10篇 |
1995年 | 16篇 |
1994年 | 5篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1982年 | 3篇 |
1979年 | 3篇 |
1977年 | 1篇 |
排序方式: 共有1411条查询结果,搜索用时 312 毫秒
141.
Sound stimulates the tympanic membrane (TM) of anuran amphibians through multiple, poorly understood pathways. It is conceivable
that interactions between the internal and external inputs to the TM contribute to the nonlinear effects that noise is known
to produce at higher levels of the auditory pathway. To explore this issue, we conducted measurements of TM vibration in response
to tones in the presence of noise in the frog Eupsophus calcaratus. Laser vibrometry revealed that the power spectra (n = 16) of the TM velocity in response to pure tones at a constant level of 80 dB sound-pressure level (SPL) had a maximum
centered at an average frequency of 2,344 Hz (range 1,700–2,990 Hz) and a maximum velocity of 61.1 dB re 1 μm/s (range 42.9–66.6
dB re 1 μm/s). These TM-vibration velocity response profiles in the presence of increasing levels of 4-kHz band-pass noise
were unaltered up to noise levels of 90 dB SPL. For the relatively low spectral densities of the noise used, the TM remains
in its linear range. Such vibration patterns facilitate the detection of tonal signals in noise at the tympanic membrane and
may underlie the remarkable vocal responsiveness maintained by males of E. calcaratus under noise interference. 相似文献
142.
Community-based vulnerability assessment has often assumed that the local is the relevant level of adaptation to climate change.
This paper suggests that not only do a number of levels from the international to the regional influence which adaptations
can take place locally, but the governance network that is made up by actors on different levels may to a large extent be
formed in responses to globalising factors, such as internationalisation of economies and the changing role of the state.
The paper presents a study of adaptation in reindeer (Rangifier tarandus) herding, forestry and fishing communities in northern Norway, Sweden, and Finland, with a focus on assessing stakeholders’
own perceptions of environmental, socio-political and economic factors that affect them. In general, the paper illustrates
the integration of non-subsistence economies into large and complex interactions where local adaptation is a result of the
sum of stresses impacting individual entrepreneurs, and the potential they have to adapt their practices given governance
(and their access to support) on different scales.
相似文献
E. Carina H. KeskitaloEmail: |
143.
Occupational exposure limits (OELs) developed by authorities play a key role in the implementation of programs to protect workers against hazardous chemicals. Unfortunately, many hazardous substances do not have OELs or the OEL could be outdated. To assure the health of the workers, it is therefore useful for companies to develop corporate OELs. An inhouse strategy will be presented hereafter. Expertise in toxicology, industrial hygiene, and occupational health should be available within the company and clear selection criteria for substances are needed. A corporate OEL is only developed for hazardous substances (e.g., carcinogenic or reprotoxic) with a high potential for worker exposure when an appropriate national OEL or threshold limit value is not available. The methodology to calculate corporate OELs is based on the existing methods for national or community OELs and also on the guidance from the European Union's (EU) regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). For carcinogenic substances with a nonthreshold mode of action, there is always a residual chance that a cancer develops even when the exposure of workers is low. To establish an OEL for these substances, the “German traffic light model” is recommended. It is pragmatic, defines an unacceptable, tolerable, and acceptable risk level when workers are exposed to these substances, and determines risk management for exposure reduction. Overall, the professional practice to develop OELs is a good example of corporate leadership to proactively protect the health of workers. 相似文献
144.
145.
介绍了二甲基甲酰胺(DMF)在人体的代谢、毒性作用和临床表现,以及DMF职业接触标志物的研究进展。 相似文献
146.
147.
有毒化合物质谱分类是以光谱数据的数值特性为基础的。这此数据的计算机分类提供了各种参数,用以确定属于有毒化合物中某一类的对应化合物。质谱数据的简单分类算法常被用于自相关变换质谱的主分量建模。主分量的有效值为相互确认为确定。对环境空气中119种被监测的有毒化合物,有色谱-质谱联用的试验和校正数据所得到的4类预报正确率为76.5%。 相似文献
148.
随着现代农业的发展,世界范围内使用的农药品种越来越多,用量不断增加。农药对非靶生物的影响以及农药残留导致环境污染,造成生态系统结构和功能的破坏,早已受到了国内外的广泛关注。有关农药对生态系统中消费者类群毒性效应的研究较多。近年来,农药对于生态系统初级生产者- 藻类的毒性及其生态毒理学的研究倍受重视。大力开展这方面的研究对于深入了解农药在生态系统中的迁移、转化及整体生态效应以及农药的生态风险评价无疑具有重要的理论意义和应用价值。本文综述了近年来国内外有关农药对单种藻类和藻类群落的毒性效应,影响毒性的环境因子。 相似文献
149.
我国云南省曲靖的宣威和富源等地是全世界肺癌高发区,为了研究环境介质中铜(Cu)等重金属的暴露与体内分布特征,探讨Cu与肺癌的相关性,在当地开展肺癌环境流行病学调查,采集宣威和富源高发区人群饮食、饮水以及人体血浆和肺组织样品,微波消解ICP-MS法测定样品中Cu等元素.结果显示,当地居民使用燃料类型是影响肺癌高发的重要因素.高发区人群Cu的日摄入总量低于我国推荐的每日膳食中营养素供给量(RDA).肺癌组血液中Cu含量显著高于对照组,肺癌组织中Cu含量显著高于癌旁组织和正常组织,且肺癌患者的血浆和肺组织中Cu/Zn比值均升高.Pearson相关性分析结果表明,Cu和Ni、Cu和Pb呈显著正相关,提示在致癌作用上具有协同效应;Cu和Fe、Cu和Zn呈显著负相关,提示具有抑制或拮抗作用.多因素Logistic回归结果表明,Cu是肺癌发生的重要影响因素,人体中Cu含量和Cu/Zn比值可为肺癌的早期预防和诊断提供科学依据. 相似文献
150.
Mann RE Stoduto G Butters J Ialomiteanu A Boase P Asbridge M Chipman M Wickens CM 《Journal of Safety Research》2010,41(5):445-449