全文获取类型
收费全文 | 611篇 |
免费 | 96篇 |
国内免费 | 62篇 |
专业分类
安全科学 | 261篇 |
废物处理 | 9篇 |
环保管理 | 132篇 |
综合类 | 197篇 |
基础理论 | 103篇 |
环境理论 | 2篇 |
污染及防治 | 18篇 |
评价与监测 | 18篇 |
社会与环境 | 15篇 |
灾害及防治 | 14篇 |
出版年
2024年 | 4篇 |
2023年 | 47篇 |
2022年 | 42篇 |
2021年 | 35篇 |
2020年 | 35篇 |
2019年 | 42篇 |
2018年 | 27篇 |
2017年 | 28篇 |
2016年 | 32篇 |
2015年 | 40篇 |
2014年 | 31篇 |
2013年 | 49篇 |
2012年 | 33篇 |
2011年 | 37篇 |
2010年 | 37篇 |
2009年 | 41篇 |
2008年 | 25篇 |
2007年 | 20篇 |
2006年 | 37篇 |
2005年 | 22篇 |
2004年 | 9篇 |
2003年 | 14篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 16篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有769条查询结果,搜索用时 15 毫秒
201.
202.
This study developed and tested a cross‐level model of the relationship between two components of active learning climate—enactive exploration and guided learning—and employee errors, and the moderating roles of the individual's traits of openness to experience and conscientiousness. The study examined the medical errors made by 142 resident physicians in 22 hospital departments. Results demonstrated significant interactions between climate and traits: when an individual had a low level of the trait of openness to experience, there was a curvilinear relationship between enactive exploration climate and number of errors. With a high level of openness to experience, the enactive exploration climate was positively associated with the number of errors up to a certain point. In addition, when an individual had a low level of conscientiousness, there was a negative association between guided learning climate and number of errors; with a high level of conscientiousness, there was a positive association between guided learning climate and number of errors. Thus, individual performance was better when the climate complemented the individual's lack of a trait. When the level of the individual's trait was high, the climate intensified the already pronounced trait up to an extent that impaired the individual's performance. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
203.
研究多点电喷汽油机燃用不同掺混比的乙醇/汽油混合燃料时的排放及催化器的转化性能.结果表明,在汽油机参数未做任何调整的情况下,与汽油机相比,乙醇/汽油混合燃料汽油机催化器之前的CO排放降低,降幅接近15%;HC排放在大负荷时略有升高;NOx排放基本相同;乙醇对排放物催化转换效率的影响与电喷汽油机的转速、负荷和空燃比控制策略有关.用气相色谱分析仪测录的未燃乙醇排放在大负荷时略有升高,甲醇排放量变化不大,乙醛排放量随乙醇含量增大而增大,经三效催化转化器后,可以被控制在接近零排放的水平.在怠速工况,随乙醇含量增加,CO、HC和NOx的排放与汽油机相比略有降低. 相似文献
204.
Michel Jules Dreyfus-Len 《Ecological modelling》1999,120(2-3)
A model to mimic the search behaviour of fishermen is built with two neural networks to cope with two separate decision-making processes in fishing activities. One neural network deals with decisions to stay or move to new fishing grounds and the other is constructed for the purpose of finding prey within the fishing areas. Some similarities with the behaviour of real fishermen are found: concentrated local search once a prey has been located to increase the probability of remaining near a prey patch and the straightforward movement to other fishing grounds. The artificial fisherman prefers areas near the port when conditions in different fishing grounds are similar or when there is high uncertainty in its world. In the latter case a reluctance to navigate to other areas is observed. The artificial fisherman selects areas with higher concentration of prey, even if they are far from the port of departure, unless a high uncertainty is related to the fishing ground. Connected areas are preferred and followed in orderly fashion if a higher catch is expected. The observed behaviour of the artificial fisherman in uncertain scenarios can be described as a risk-averse attitude. The approach seems appropriate for an individual-based modelling of fishery systems, focusing on the learning and adaptive characteristics of fishermen and on interactions that take place at a fine scale. 相似文献
205.
医用输液生产中药品安全隐患分析及对策 总被引:1,自引:0,他引:1
杨福刚 《中国安全科学学报》2010,20(5)
针对医用输液生产中易受到异物污染、存在安全隐患的现状,分析安全隐患产生的主要环节及成因。当前生产中普遍采用的人工灯检方法,由于劳动强度大、工人易疲劳,并不能从源头上完全杜绝含有异物微粒的输液进入临床。为此,提出利用机器视觉技术对输液中异物微粒进行在线自动检测的解决方案。首先建立输液中异物粒子的运动轨迹数学模型;然后提取输液视觉图像序列中每个可能目标的有效特征,通过特征匹配和轨迹关联进行甄别检测;最后对视觉系统进行标定,确定检测到的异物微粒的粒径大小及微粒数量。实验表明,该技术对输液中微小异物检出确率达95%以上,能从源头上有效避免医用输液生产中异物污染。 相似文献
206.
苏南现代化进程中的遥感土地利用动态监测——以苏、锡、常地区为例 总被引:10,自引:2,他引:8
地少人多的广大苏南地区早在60年代已形成了强大的经济实力,改革开放以来,乡镇企业的迅速崛起带动了地区经济的全面发展。随着苏南经济的迅速发展,土地开发和利用方式也发生了较大变化。人地矛盾、人与空间的不协调日益严重。改善投资环境、合理利用城市土地、促进苏南经济的持续、快速发展,必须更好地实现土地利用的动态监测。为了适应这种新的需求,本文以苏、锡、常地区土地动态变化研究为背景,采用人机交互式解译遥感图像,将多时相遥感信息进行复合,用地理信息系统软件进行分析处理并输出图件。并对苏、锡、常地区的土地利用动态变化特点、各类型变化情况进行了具体分析。实践证明,该方法是行之有效的 相似文献
207.
ABSTRACTCommunity-based initiatives and collective learning practices are key themes in sustainability transition processes. This paper presents the results of a participatory study that investigated a local initiative in the community of Lomba do Pinheiro in south Brazil to examine social learning processes in the context of socio-ecological vulnerability. In this community, a group composed of local residents and members representing the public sector and local educational institutions has promoted several learning-oriented actions aimed at restoring a degraded local watershed and improving residents’ livelihoods. This study used social learning as a lens through which the initiative enacted by this group may be understood, and analysed how local conditions, determined by a context of vulnerability, have influenced local processes. We applied a multi-dimensional analytical framework that included individual, collective, and territorial dimensions. The analysis focused on the leading group, the individuals who comprise it, and their actions in the territory, while considering local constraints. Our findings highlight the importance of (1) shared values, mutual trust, and affective bonds for group cohesion as well as concerted action, equalisation of diverse languages within the group, knowledge integration, and initiative persistence; (2) a practical-reflexive approach based on a sequence of actions that catalyses group learning and facilitates advancement within the wider community; and (3) the role of inter-sectoral articulations and the establishment of partnerships to support actions. This paper raises questions about the limits of an exclusively bottom-up approach to solve complex problems in the context of extremely precarious conditions. 相似文献
208.
209.
210.
扬州电厂200MW机组烟气脱硫石灰石制粉系统 总被引:6,自引:0,他引:6
介绍了扬州电厂石灰石制粉系统、主要设计参数及其核心设备的技术特点,为同类工程提供参考。 相似文献