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   1323篇
  免费   34篇
  国内免费   22篇
电工技术   25篇
综合类   144篇
化学工业   68篇
金属工艺   22篇
机械仪表   21篇
建筑科学   133篇
矿业工程   34篇
能源动力   6篇
轻工业   33篇
水利工程   71篇
石油天然气   37篇
无线电   26篇
一般工业技术   48篇
冶金工业   521篇
原子能技术   3篇
自动化技术   187篇
  2023年   12篇
  2022年   13篇
  2021年   21篇
  2020年   20篇
  2019年   18篇
  2018年   11篇
  2017年   17篇
  2016年   29篇
  2015年   27篇
  2014年   53篇
  2013年   53篇
  2012年   38篇
  2011年   85篇
  2010年   93篇
  2009年   85篇
  2008年   87篇
  2007年   99篇
  2006年   94篇
  2005年   82篇
  2004年   67篇
  2003年   57篇
  2002年   58篇
  2001年   28篇
  2000年   20篇
  1999年   20篇
  1998年   12篇
  1997年   10篇
  1996年   14篇
  1995年   9篇
  1994年   3篇
  1993年   3篇
  1988年   3篇
  1986年   3篇
  1984年   2篇
  1982年   4篇
  1981年   2篇
  1974年   2篇
  1966年   4篇
  1965年   10篇
  1964年   15篇
  1963年   13篇
  1962年   4篇
  1961年   11篇
  1960年   9篇
  1959年   4篇
  1958年   8篇
  1957年   4篇
  1956年   6篇
  1955年   18篇
  1954年   5篇
排序方式: 共有1379条查询结果,搜索用时 601 毫秒
101.
学习质量分析是一个复杂的过程,首先探讨了影响成绩质量的几种不确定性因素,给出了直观分析模型、概率分析模型、概率推理分析模型等3种成绩分析模型,通过学生的学习成绩较系统地分析了学生的学习质量,最后利用MYCIN概率推理分析模型对一具体实例进行了智能分析。  相似文献   
102.
The authors investigated subgroup differences on a multiple-choice and constructed-response test of scholastic achievement in a sample of 197 African American and 258 White test takers. Although both groups had lower mean scores on the constructed-response test, the results showed a 39% reduction in subgroup differences compared with the multiple-choice test. The results demonstrate that the lower subgroup differences were explained by more favorable test perceptions for African Americans on the constructed-response test. In addition, the two test formats displayed comparable levels of criterion-related validity. The results suggest that the constructed-response test format may be a viable alternative to the traditional multiple-choice test format in efforts to simultaneously use valid predictors of performance and minimize subgroup differences in high-stakes testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
103.
The socioeconomic stratification of American society profoundly influences how the life course unfolds by shaping various developmental pathways as well as the connections among these pathways. Drawing on a nationally representative sample of American adolescents, this study charted trajectories of personal control and parental consultation from middle school to the end of high school and then examined how various combinations of these trajectories were associated with math/science course taking in high school across socioeconomic strata. Results indicated that low and/or decreasing levels of personal control were associated with the accumulation of fewer math/science credits, as were declining levels of parental consultation no matter what the initial level. Mismatches between control and consultation trajectories (e.g., high, stable control with low, stable consultation) were also associated with fewer math/science credits. These patterns tended to be less predictive of math/science credit accumulation at the highest and lowest ends of the socioeconomic spectrum. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
104.
The authors examined cultural differences in parents' responses to their children's performance. In Study 1 (N = 421), Chinese 5th graders reported that their parents de-emphasized their academic success and emphasized their academic failure, whereas their American counterparts reported that their parents did the opposite. This partially accounted for Chinese (vs. American) children responding less positively to success and more negatively to failure. In Study 2 (N = 128), Chinese and American mothers' responses to their 4th and 5th graders' performance were observed in the laboratory. The cultural differences in children's reports of parents' responses documented in Study 1 were replicated; mothers' responses were also associated with children's subsequent performance. In addition, Chinese mothers were more involved than were American mothers, but their affect was similar. Taken together, the results suggest that parents' responses to children's performance may be a channel for cultural transmission and perpetuation of responses to performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
Peer nomination procedures were used to explore the development of academic achievement values and their relation to perceptions of barriers to opportunity. A total of 615 boys and girls across 3 grade levels (2nd, 4th, 7th) and 2 ethnic groups (African American, Latino) nominated peers who they admired, respected, and wanted to be like. Nominations were summed to create a value index. Girls in both ethnic groups and across grade levels were more likely to nominate high- or average-achieving same-gender classmates as those who they admired, respected, and wanted to be like. Second- and 4th-grade boys in both ethnic groups reported a nomination pattern similar to that of girls. However, 7th-grade boys in both ethnic groups showed a relative preference for low-achieving same-gender classmates as valued. Perceptions of barriers were related to increasing valuing of low achievers among African American 7th-grade boys. Implications of the findings for understanding the motivational challenges of ethnic minority male adolescents are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
106.
The authors developed a grounded theory about how a school serving relatively advantaged children produces high reading and writing achievement compared with schools serving similar populations of students. The school's faculty is reading and writing focused, and students experience many books as they receive explicit, demanding instruction (i.e., about how to read words, comprehend, write) connected to content learning. The school offers a positive, motivating environment. In sum, many elements that potentially supported achievement were identified, including explicit teaching of skills in the context of much reading, writing, and content learning, which is consistent with balanced perspectives on reading and writing development. A major hypothesis in the grounded theory is that even with relatively advantaged populations, great efforts may be required to produce high reading and writing achievement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
107.
Stigmatization can give rise to belonging uncertainty. In this state, people are sensitive to information diagnostic of the quality of their social connections. Two experiments tested how belonging uncertainty undermines the motivation and achievement of people whose group is negatively characterized in academic settings. In Experiment 1, students were led to believe that they might have few friends in an intellectual domain. Whereas White students were unaffected, Black students (stigmatized in academics) displayed a drop in their sense of belonging and potential. In Experiment 2, an intervention that mitigated doubts about social belonging in college raised the academic achievement (e.g., college grades) of Black students but not of White students. Implications for theories of achievement motivation and intervention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
108.
概括介绍了刘明教授的新作《学术评价制度批判》的主要内容,认为该书资料翔实、视野开阔、分析透彻、针对性强,显示出了较高的学术价值,是改革和完善学术评价制度的“引玉”之作。该书的出版,填补了我国在学术评价领域研究的空白,有非常重要的现实指导意义。  相似文献   
109.
文章以某高校两个工科班学生为实例,分别从入学成绩、生源、性别、班级和宿舍等方面,运用方差分析t、检验和聚类分析等分析方法,探讨了以上因素对高校学生基础课学业成绩的影响,并据此提出了提高学生学业成绩的若干对策建议。  相似文献   
110.
Studies have shown that multitasking with technology, specifically using Social Networking Sites (SNSs), decreases both efficiency and productivity in an academic setting. This study investigates multitasking’s impact on the relationship between SNS use and Grade Point Average (GPA) in United States (US; n = 451) and European (n = 406) university students using quantitative and qualitative data analysis. Moderated Multiple Regression analysis results showed that the negative relationship between SNS use and GPA was moderated by multitasking only in the US sample. This may be due to European students being less prone to “disruptive” multitasking. The results provide valuable cautionary information about the impact of multitasking and using SNSs in a learning environment on university students’ GPAs.  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