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   474篇
  免费   5篇
电工技术   1篇
化学工业   113篇
金属工艺   2篇
机械仪表   1篇
建筑科学   15篇
矿业工程   11篇
能源动力   1篇
轻工业   68篇
水利工程   1篇
无线电   21篇
一般工业技术   36篇
冶金工业   137篇
自动化技术   72篇
  2019年   9篇
  2018年   6篇
  2014年   5篇
  2013年   30篇
  2012年   17篇
  2011年   16篇
  2010年   11篇
  2009年   10篇
  2008年   18篇
  2007年   19篇
  2006年   13篇
  2005年   12篇
  2004年   12篇
  2003年   4篇
  2002年   4篇
  2001年   5篇
  2000年   6篇
  1999年   9篇
  1998年   7篇
  1997年   6篇
  1996年   6篇
  1995年   7篇
  1994年   8篇
  1993年   4篇
  1991年   4篇
  1990年   5篇
  1989年   4篇
  1988年   7篇
  1987年   6篇
  1986年   8篇
  1985年   8篇
  1984年   8篇
  1983年   7篇
  1982年   8篇
  1981年   10篇
  1980年   7篇
  1979年   9篇
  1978年   7篇
  1977年   4篇
  1976年   8篇
  1975年   5篇
  1974年   6篇
  1973年   5篇
  1966年   4篇
  1961年   4篇
  1959年   12篇
  1958年   12篇
  1957年   13篇
  1956年   4篇
  1955年   13篇
排序方式: 共有479条查询结果,搜索用时 515 毫秒
451.
452.
453.
OBJECTIVE: To investigate whether aggression, parent and peer influences, and previous traffic-related experiences at ages 15 and 18 impacted on (a) differences between the perceived safe and estimated legal alcohol consumption limit, and (b) driving while impaired (DWI) behaviour at age 21. METHOD: The study population was a birth cohort involved in a longitudinal investigation of health and development. At the ages of 15 and 18, study members completed questionnaires assessing parent and peer attachment, experience travelling with an alcohol impaired adult or youth, aggression, and previous crash experience. At age 21, study members were questioned about how much alcohol they perceived they could drink and still drive safely, and whether they had driven after 'perhaps consuming too much alcohol'. For each participant their legal alcohol consumption limit was estimated using their height and weight. Path analysis was used to determine whether variables measured at ages 15 and 18 predicted differences between the perceived safe and estimated legal alcohol consumption limit and driving while impaired, both measured at age 21. RESULTS: Insufficient females drove while impaired at age 21, who also had complete data on all other variables, to conduct path analysis for this outcome. For males, aggression at ages 15 and 18, travelling with an impaired youth at age 18, and previous crash experience at age 18 predicted DWI behaviour at age 21. Only aggression at age 15 predicted the difference between perceived safe and estimated legal alcohol consumption limit for the males. For females, aggression at ages 15 and 18, and travelling with an impaired adult at age 15 predicted the difference between perceived safe and estimated legal alcohol consumption limit. CONCLUSION: The results show that aggressive behaviours and adult and/or youth modelling of drink driving behaviours in mid- to late-adolescence are related to differences between perceived safe and estimated legal alcohol consumption limit for both genders and driving while impaired for males.  相似文献   
454.
The main aim of this study was to identify adolescent/young adulthood factors that predicted persistent driving after drinking, persistent unsafe driving after drinking, and persistent cannabis use and driving among young adults. It was a longitudinal study of a birth cohort (n=933, 474 males and 459 females) and was based on data collected at ages 15, 18, 21 and 26 years. At each of these ages members of the cohort attended the research unit for a personal interview by a trained interviewer, using a standardised questionnaire. For this study, the data for the outcome measures (persistent driving after drinking, persistent unsafe driving after drinking, and persistent driving after using cannabis) were obtained at ages 21 and 26 years. The main explanatory measures were collected at ages 15, 18, 21 years and included demographic factors (academic qualifications, employment, parenting); personality measures; mental health measures (substance use, cannabis dependence, alcohol dependence, depression); anti-social behaviour (juvenile arrest, aggressive behaviour, court convictions); early driving behaviour and experiences (car and motorcycle licences, traffic crashes).The analyses were conducted by gender. The results showed that females who persisted in driving after drinking (13%, n=61) were more likely than the others to have a motorcycle licence at 18. The males who persisted in driving after drinking (28%, n=135) were more likely than the other males to have some school academic qualifications and to be employed at age 26. Compared to the other males, those who persisted in unsafe driving after drinking (4%, n=17) were more likely to be aggressive at 18 and alcohol dependent at 21. Only six (1%) females persisted in unsafe driving after drinking so regression analyses were not conducted for this group. For persistent driving after using cannabis, the univariate analyses showed that females who persisted with this behaviour tended to have high substance use at 18, cannabis dependence at 21, police contact as a juvenile, and to be a parent at 21. For this group, because of the small numbers (3%, n=13) multivariate analyses were not appropriate. For the males who persisted in driving after using cannabis (14%, n=68) a wide range of variables were significant at the univariate stage. The multivariate analysis showed that the most important factors were dependence on cannabis at 21, at least one traffic conviction before 21, a non traffic conviction before 18, and low constraint at 18. CONCLUSION: These results show different characteristics were associated with persistence in each of these outcome behaviours. This indicates that different approaches would be required if intervention programmes were to be developed to target these behaviours.  相似文献   
455.
456.
457.
458.
459.
460.
Subjected data on overlapping affiliation within the 29 divisions of the American Psychological Association for Associates, Members, and Fellows in 1970 to factor analysis. Both phi coefficients and Winer coefficients (i.e., cosines of the angles between 2 group vectors) were used. An interpretation based on a 7-factor solution for Members and Fellows led to the following factors: (a) clinical or psychotherapy, (b) developmental, (c) physiological-experimental, (d) general, (e) consumer-industrial, (f) engineering-military, and (g) educational. A 3-factor solution (combining clinical and developmental; physiological-experimental and general; and engineering-military, consumer-industrial, and educational) suggested 3 superdivisions: general, applied, and developmental. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  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