全文获取类型
收费全文 | 729篇 |
免费 | 80篇 |
国内免费 | 144篇 |
专业分类
安全科学 | 108篇 |
废物处理 | 27篇 |
环保管理 | 164篇 |
综合类 | 360篇 |
基础理论 | 93篇 |
污染及防治 | 63篇 |
评价与监测 | 28篇 |
社会与环境 | 90篇 |
灾害及防治 | 20篇 |
出版年
2024年 | 6篇 |
2023年 | 11篇 |
2022年 | 37篇 |
2021年 | 33篇 |
2020年 | 38篇 |
2019年 | 34篇 |
2018年 | 30篇 |
2017年 | 43篇 |
2016年 | 41篇 |
2015年 | 38篇 |
2014年 | 30篇 |
2013年 | 52篇 |
2012年 | 55篇 |
2011年 | 70篇 |
2010年 | 39篇 |
2009年 | 46篇 |
2008年 | 30篇 |
2007年 | 58篇 |
2006年 | 48篇 |
2005年 | 34篇 |
2004年 | 23篇 |
2003年 | 29篇 |
2002年 | 22篇 |
2001年 | 19篇 |
2000年 | 17篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 7篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有953条查询结果,搜索用时 156 毫秒
81.
82.
Perceived changes in well-being and happiness with gardening in urban organic allotments in Portugal
Urban allotment gardens (AG) in Portugal have increased in recent years, as in many other European countries and worldwide. The contribution of these gardens to the happiness and well-being of urban populations has been recognized, but evaluations of their benefits are still very scarce. The objective of this study was to evaluate this contribution, based on the urban organic AG of the Devesa Park in Vila Nova de Famalicão, Portugal. The sample included 65 gardeners who completed the self-administered questionnaires of Bem-Estar Pessoal (personal well-being scale), Felicidade Subjetiva (subjective happiness scale) and sociodemographic characteristics. Respondents were mainly adults under 65 years, married and academically well qualified and about half of them had a professional activity, with nearly one third being retired. They considered themselves happy with their life (Personal Well-being Index = 74.5%) and revealed an optimistic and positive attitude towards life, regardless of economic or social difficulties. The increased frequency of visits for gardening was positively related to a greater perception of subjective happiness. The gardeners who visited the AG more frequently considered themselves happier from a self-perspective and in comparison with peers. It can be suggested that urban organic AG represent a means for enhancing citizen well-being, contributing positively to their feelings of happiness and life satisfaction, changing behaviours and developing personal capacities. Beyond economic measures, urban AG can be recommended to capture the well-being of societies. 相似文献
83.
飞行员人因可靠性定量预测 总被引:1,自引:0,他引:1
为有效预测飞行员的人因可靠性,以保障飞行安全,基于认知可靠性与失误分析法(CREAM)的扩展法,建立飞行员人因可靠性定量预测模型。依据飞行员的任务特点,调整认知行为及认知功能。通过优化共同绩效条件(CPC)因子水平等级,并增加新的因子,改进CPC因子依赖规则,用于修正因子的初始评估结果,解决扩展法未考虑因子间关系的问题,从而完成模型的建立。利用回看分析法验证模型的有效性,采用所建立的模型和扩展法分别对已发生的飞行案例进行预测,并与实际发生结果对比分析。结果表明,与扩展法相比,采用飞行员定量预测模型得到的预测结果与案例发生结果所反映的控制模式更为匹配。 相似文献
84.
Magdalena Woynarowska-Sołdan Lucyna Iwanow Aleksander Zarzeka Joanna Gotlib 《International journal of occupational safety and ergonomics》2019,25(1):76-85
Purpose. The aim was to adjust the positive health behaviours scale (PHBS) to make it suitable for use by nurses, and to validate the new version of the tool. Methods. A previously formulated PHBS was modified. The scale comprises 29 statements describing certain positive health behaviours in four subscales: nutrition, physical activity, relaxation and behaviours related to mental health, and preventive behaviours. The scale was enriched with items on avoiding risky behaviours and a question regarding respondents’ own assessment of their care for health. Analyses were conducted of reliability, construct validity, criterion validity and dimensionality of subscales. The questionnaire was completed by 1017 nurses. Results. Cronbach's α reached 0.844 for the entire scale and 0.623–0.761 for specific subscales. Empirical data did not confirm theoretical assumptions regarding the existence of a four-element structure of the PHBS. The scale's diagnostic criteria were validated on the basis of positive results of correlation and trend analysis. Only one of the subscales proved homogeneous and could be considered unidimensional. Conclusions. The results confirmed the high internal consistency of the scale and its subscales. The factor structure of the PHBS was equivocal. The PHBS could be used in workplace-based health promotion programmes designed for nurses. 相似文献
85.
86.
Rethinking Community-Based Conservation 总被引:34,自引:0,他引:34
FIKRET BERKES 《Conservation biology》2004,18(3):621-630
Abstract: Community-based conservation (CBC) is based on the idea that if conservation and development could be simultaneously achieved, then the interests of both could be served. It has been controversial because community development objectives are not necessarily consistent with conservation objectives in a given case. I examined CBC from two angles. First, CBC can be seen in the context of paradigm shifts in ecology and applied ecology. I identified three conceptual shifts—toward a systems view, toward the inclusion of humans in the ecosystem, and toward participatory approaches to ecosystem management—that are interrelated and pertain to an understanding of ecosystems as complex adaptive systems in which humans are an integral part. Second, I investigated the feasibility of CBC, as informed by a number of emerging interdisciplinary fields that have been pursuing various aspects of coupled systems of humans and nature. These fields—common property, traditional ecological knowledge, environmental ethics, political ecology, and environmental history—provide insights for CBC. They may contribute to the development of an interdisciplinary conservation science with a more sophisticated understanding of social-ecological interactions. The lessons from these fields include the importance of cross-scale conservation, adaptive comanagement, the question of incentives and multiple stakeholders, the use of traditional ecological knowledge, and development of a cross-cultural conservation ethic. 相似文献
87.
历史时期黄河下游河道演变规律与淮河灾害治理 总被引:9,自引:0,他引:9
历史时期黄河下游河道演变规律表明,河流从沿程淤积到河口延伸、再到溯源淤积的自适应过程,在1000a、100a、50a、10a等各种时间尺度上均可能发生,这对淮河水系改造的可行性论证、方案设计等有重要指导意义。 相似文献
88.
89.
90.