首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   236篇
  免费   8篇
化学工业   41篇
金属工艺   1篇
机械仪表   2篇
建筑科学   13篇
能源动力   1篇
轻工业   18篇
水利工程   2篇
无线电   15篇
一般工业技术   33篇
冶金工业   89篇
自动化技术   29篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   4篇
  2019年   7篇
  2018年   7篇
  2017年   1篇
  2016年   4篇
  2015年   1篇
  2014年   2篇
  2013年   14篇
  2012年   4篇
  2011年   14篇
  2010年   9篇
  2009年   9篇
  2008年   14篇
  2007年   14篇
  2006年   12篇
  2005年   3篇
  2004年   11篇
  2003年   8篇
  2002年   9篇
  2001年   5篇
  2000年   3篇
  1999年   5篇
  1998年   10篇
  1997年   5篇
  1996年   9篇
  1995年   3篇
  1994年   8篇
  1993年   5篇
  1992年   3篇
  1991年   2篇
  1990年   5篇
  1987年   8篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1980年   1篇
  1977年   4篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
  1967年   1篇
  1966年   3篇
  1965年   2篇
  1964年   1篇
  1963年   1篇
  1962年   1篇
排序方式: 共有244条查询结果,搜索用时 15 毫秒
101.
Broad community-scale, collaborative planning processes can help stakeholders develop trust. However, planners should also consider ways to develop trust before embarking on larger community processes. When relationships are fostered between community organizations through smaller planning exercises, those relationships can lead to unexpected and innovative outcomes. Such partnerships lead to independent projects as well as to more effective participation in formalized, broad-based planning. The central components of small working sessions and of their process include allowing relationships to develop over time, creating alternative narratives in the context of community conflict, and validating local knowledge in formal planning discourse. What our experience tells us is that although trust can be built in large, formalized processes, when community members learn to work together beforehand, that earlier groundwork facilitates more effective participation in later projects. Planning as discussed here is iterative and supported by local NGOs in Monteverde, Costa Rica.  相似文献   
102.
Examined relations between social activity and state and trait measures of Positive and Negative Affect. In Study 1, Ss completed scales relevant to 3-factor models of personality and a weekly mood and social activity questionnaire for 13 wks. In Study 2, Ss completed measures of the 5-factor model of personality and a daily mood and social activity survey for 6–7 wks. In within- and between-Ss analyses, socializing correlated significantly with state measures of Positive Affect and with trait measures of Extraversion/Positive Emotionality. These relations were relatively general across various types of positive affect and social events; however, specific types of social events also were differentially related to affect. In contrast, social activity had no consistent association with measures of Negative Affect or the other personality dimensions. The results support a temperamental view of Extraversion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
103.
Contemporary studies of chemical contamination in Antarctica commonly focus on remnants of historical local releases or long-range transport of legacy pollutants. To protect the continent's pristine status, the Antarctic Treaty's Protocol on Environmental Protection prohibits importation of persistent organic pollutants. However, some polybrominated diphenyl ether (PBDE) congeners exhibit similar properties. Many modern polymer-containing products, e.g., home/office furnishings and electronics, contain percent levels of flame retardant PBDEs. PBDE concentrations in indoor dust and wastewater sludge from the U.S. McMurdo and New Zealand-operated Scott Antarctic research bases were high. Levels tracked those in sludge and dust from their respective host countries. BDE-209, the major constituent in the commercial deca-PBDE product, was the dominant congener in sludge and dust, as well as aquatic sediments collected near the McMurdo wastewater outfall. The pattern and level of BDE-209 sediment concentrations, in conjunction with its limited environmental mobility, suggest inputs from local sources. PBDE concentrations in fish and invertebrates near the McMurdo outfall rivaled those in urbanized areas of North America and generally decreased with distance. The data indicate that reliance on wastewater maceration alone, as stipulated by the Protocol, may permit entry of substantial amounts of PBDEs and other chemicals to the Antarctic environment.  相似文献   
104.
A controversy exists over whether results of randomized controlled trials of psychological treatment methods generalize to routine clinical practice. To examine the generalizability of cognitive-behavioral interventions for anxiety disorders, a meta-analysis of 11 effectiveness studies was conducted. Only studies that closely approximated real-world clinical practice were included in the present meta-analysis (e.g., studies were conducted in a nonuniversity setting, practitioners had regular caseloads, clients were not excluded if they had comorbid conditions). Cognitive-behavioral interventions were associated with significant improvement in anxiety symptoms at the end of treatment (dw = 1.35) and again at follow-up (dw = 1.14). On the basis of these results, it seems that cognitive-behavioral interventions for anxiety disorders generalize to real-world clinical practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
106.
Girls who grow up in households with an unrelated adult male reach menarche earlier than peers, a finding hypothesized to be an evolutionary strategy for families under stress. The authors tested the alternative hypothesis that nonrandom selection into stepfathering due to shared environmental and/or genetic predispositions creates a spurious relation between stepfathering and early menarche. Using the unique controls for genetic and shared environmental experiences offered by the children-of-twins design, the authors found that cousins discordant for stepfathering did not differ in age of menarche. Moreover, controlling for mother's age of menarche eliminated differences in menarcheal age associated with stepfathering in unrelated girls. These findings strongly suggest selection, and not causation, accounts for the relationship between stepfathering and early menarche. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
107.
Home ownership is currently not an option for Indigenous people living outside of urban centres. This article presents the results of a household survey conducted in four community settlements in Queensland revealing diverse understandings, aspirations and concerns for Indigenous home ownership. Discussion concludes that the development of a home ownership scheme will require rigorous policy analysis and innovative economic and cultural solutions.  相似文献   
108.
109.
110.
Polycaprolactone (PCL) and PCL-based materials are widely applied in the biomedical field, however, their slow biodegradation profile makes them more suitable to be used in hard tissues, where healing requires longer periods of time. In order to adjust their properties to suit for soft tissues applications, PCL can be blended with other biodegradable materials in order to tune its degradation rate. Herein, polymeric blends of PCL and castor oil (CO) were prepared after their chemical modification with 2-isocyanatoethylmethacrylate (IEMA) in order to be applied as photocrosslinkable tissue adhesives. These functionalized macromers were chemically characterized and used to prepare polymeric blends (PCL-IEMA/CO-IEMA) with variable mass proportions. A biocompatible photoinitiator (Irgacure 2959) was added to these macromers blends which were then irradiated under UV light. The feasibility of the prepared materials as tissue adhesives was evaluated by assessment of their chemical/physical properties as well as their interaction with blood. Moreover, their cytotoxic profile was also evaluated through in vitro studies using human dermal fibroblasts as model cells.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号