全文获取类型
收费全文 | 44464篇 |
免费 | 458篇 |
国内免费 | 370篇 |
专业分类
安全科学 | 1275篇 |
废物处理 | 1765篇 |
环保管理 | 6043篇 |
综合类 | 6574篇 |
基础理论 | 12271篇 |
环境理论 | 29篇 |
污染及防治 | 12245篇 |
评价与监测 | 2797篇 |
社会与环境 | 1991篇 |
灾害及防治 | 302篇 |
出版年
2022年 | 370篇 |
2021年 | 416篇 |
2020年 | 276篇 |
2019年 | 383篇 |
2018年 | 679篇 |
2017年 | 672篇 |
2016年 | 999篇 |
2015年 | 794篇 |
2014年 | 1219篇 |
2013年 | 3555篇 |
2012年 | 1452篇 |
2011年 | 2008篇 |
2010年 | 1613篇 |
2009年 | 1625篇 |
2008年 | 1966篇 |
2007年 | 2079篇 |
2006年 | 1814篇 |
2005年 | 1513篇 |
2004年 | 1487篇 |
2003年 | 1391篇 |
2002年 | 1392篇 |
2001年 | 1698篇 |
2000年 | 1216篇 |
1999年 | 752篇 |
1998年 | 586篇 |
1997年 | 579篇 |
1996年 | 618篇 |
1995年 | 672篇 |
1994年 | 606篇 |
1993年 | 549篇 |
1992年 | 530篇 |
1991年 | 507篇 |
1990年 | 507篇 |
1989年 | 534篇 |
1988年 | 465篇 |
1987年 | 420篇 |
1986年 | 373篇 |
1985年 | 403篇 |
1984年 | 393篇 |
1983年 | 429篇 |
1982年 | 439篇 |
1981年 | 391篇 |
1980年 | 334篇 |
1979年 | 372篇 |
1978年 | 302篇 |
1977年 | 254篇 |
1976年 | 257篇 |
1975年 | 254篇 |
1973年 | 238篇 |
1972年 | 273篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
This paper presents the design and the implementation of a methodology for measuring and improving safety culture at a nuclear power plant (NPP). The study has involved the completion of a pilot project aimed at seeing how to make use of the RADAR logic (Results, Approach, Deployment, Assessment and Review) of the EFQM model as a tool for the self assessment of safety culture in a nuclear power plant. The work was aimed at finding evidence of the safety culture that was in place at the plant and at identifying both the strengths of that culture and any areas in which it could be improved. The score obtained from an analysis of those strengths and areas for improvement has made it possible to prioritise the actions to be taken. The identification of perceptions and evidence, the agreement on the strong points and areas for improvement and the quantification of the safety culture have been performed by groups comprising volunteers who work at the NPP. The advantages of this methodology are assessed in the paper. 相似文献
982.
IntroductionThe influence of amendments to Federal Motor Vehicle Safety Standard (FMVSS) 108, requiring conspicuity treatments on heavy tractors and trailers, was determined in analyses of the odds of fatal collisions in darkness.MethodComparisons were made between crashes in which conspicuity treatment was likely relevant, and those in which it was likely irrelevant.ResultsOver 23 years, the odds that a fatal collision involving a heavy truck occurred in darkness declined by 58% among relevant crashes, while little decline was observed for irrelevant crashes. Disaggregation into crash types revealed the largest declines occurred in fatal rear-end and angle collisions. A parallel analysis of light vehicles also found declines but no differences among crash type. Similar trends were also observed for nonfatal rear end collisions.ConclusionThe results suggest that detection failure may have contributed to the risk of striking a tractor-semitrailer in darkness, and that conspicuity treatments have reduced this risk.Impact on IndustryConspicuity treatments appear to reduce risk of collision into heavy trucks in darkness. It is likely that this benefit would also extend to other vehicles that are not included in the FMVSS 108 regulation (e.g., buses, single unit trucks, recreational vehicles), although many are so equipped, regardless of the regulation. 相似文献
983.
984.
985.
986.
Terrell W. Zollinger Frank J. Vilardo Paul W. Chan David Z. McSwane 《Journal of Safety Research》1984,15(2):77-84
The purpose of this study was to estimate the total medical care costs of individuals injured in motor vehicle crashes and in crashes where alcohol was involved. Crashes were studied that involved 2,728 vehicle occupants and 191 pedestrians with injuries as reported in 1979 by the National Accident Sampling System, a probability sample of all motor vehicle crashes occurring in the united States. Medical care costs were assigned by using Abbreviated Injury Scale codes in accordance with other published research. Determination of alcohol involvement was based on crash characteristics. Results indicate that 20.2 % of medical care costs for motor vehicle crash injuries may be due to crashes where alcohol was involved. It was estimated that alcohol-related motor vehicle crashes cost between $434 million and $483 million in medical care alone in the United States in 1979. 相似文献
987.
Hypotheses were developed based on a coping model that views political behaviour (voice) as a fight response and turnover (exit) as a flight response to job stress. Data were collected from a group of professional, public employees and turnover dates were obtained for the group 13 months after completion of questionnaires. Multiple regression analysis was employed to test hypotheses. Stressors of interest were person-environment fit (P-E fit), role conflict (RC), and role ambiguity (RA). Psychological strains (job dissatisfaction and lowered commitment) were hypothesized to mediate the stressor-coping behaviour relationship. Turnover (TO) behaviour was the ultimate organizationally relevant outcome of coping behaviours. Job satisfaction and commitment were significantly related to intentions to leave. Political action was directly related to P-E fit and this relationship was not mediated by satisfaction or commitment. The relationship between RA and politics was moderated by commitment. Less committed employees tended to exhibit political behaviour in response to RA. Both coping responses (intentions to leave and political action) predicted significant portions of retention/turnover variance. 相似文献
988.
Recent theory regarding the nature of organizational commitment suggests that viewing it as comprised of two dimensions, value commitment and continuance commitment, is of theoretical and practical value. This field study found the differential antecedents of these two commitment dimensions to be consistent with the March and Simon (1958) framework using the two-dimensional organizational commitment questionnaire from Mayer and Schoorman (1992). Organizational tenure, retirement benefits, education, and age were more highly correlated with continuance commitment, while felt participation, perceived prestige, job involvement, and role ambiguity were more highly correlated with value commitment. Analysis using LISREL 7 supported the pattern of relationships between the antecedents and the two commitment dimensions. © 1998 John Wiley & Sons, Ltd. 相似文献
989.
This study investigates whether departments performing the same functions in different firms incur similar changes in structural configuration in response to industry-wide stimuli. Based on the proposition that the context of functional departments is similar across firms, changes in differentiation, integration, and perspective are hypothesized. Managers' perceptions of the validity of a series of statements to conditions five to 10 years ago and to present conditions are contrasted and show statistically significant shifts in these structural configurations. This change is confirmed by the analysis of responses of other managers in different departments within the same firms. Correlation analysis shows significant agreement among alternative measures of the same aspects of structure, and significant comovement among different structural dimensions. The later result supports the quantum theory of organizations. 相似文献
990.
This work presents a new process for dechlorinating poly-vinyl chloride (PVC) by the use of oyster-shell waste. The process consists of milling of PVC waste with oyster-shell waste, followed by washing the milled sample with water. The milling of PVC and oyster-shell mixture results in size reduction and rupture in bonds, leading to mechanically induced reactions between the two to form CaCl2 and hydrocarbon with C=C bonds. Washing the milled mixtures with water at room temperature allows complete removal of chlorine from the milled sample. More than 95% of chlorine in PVC was removed when 2h grinding is conducted for the mixture. The present process could offer a potential route to the handling and disposal of oyster-shell and PVC wastes. 相似文献