全文获取类型
收费全文 | 1326篇 |
免费 | 33篇 |
国内免费 | 23篇 |
专业分类
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 | 134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 | 27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 | 188篇 |
出版年
2023年 | 12篇 |
2022年 | 13篇 |
2021年 | 21篇 |
2020年 | 21篇 |
2019年 | 19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1382条查询结果,搜索用时 0 毫秒
921.
No authorship indicated 《Canadian Metallurgical Quarterly》1999,54(8):573a
The American Psychological Foundation (APF) Gold Medal Awards recognize distinguished and enduring records of accomplishments in 4 areas of psychology. The 1999 recipient of the Gold Medal Award for Life Achievement in the Science of Psychology is Wendell R. Garner. Garner is known for his work in psychophysics, discrimination, perception, and information processing. A citation, biography, and selected bibliography of Garner's work are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
922.
A comparison of single and multiple strategy instruction on third-grade students' mathematical problem solving. 总被引:1,自引:0,他引:1
Jitendra Asha K.; Griffin Cynthia C.; Haria Priti; Leh Jayne; Adams Aimee; Kaduvettoor Anju 《Canadian Metallurgical Quarterly》2007,99(1):115
The purposes of this study were to assess the differential effects of a single strategy (schema-based instruction; SBI) versus multiple strategies (general strategy instruction, GSI) in promoting mathematical problem solving and mathematics achievement as well as to examine the influence of word problem-solving instruction on the development of computational skills. Eighty-eight 3rd graders and their teachers were assigned randomly to conditions (SBI and GSI). Students were pre- and posttested on mathematical problem-solving and computation tests and were posttested on the Pennsylvania System of School Assessment Mathematics test, a criterion-referenced test that measures student attainment of academic standards. Results revealed SBI to be more effective than GSI in enhancing students' mathematical word problem-solving skills at posttest and maintenance. Further, results indicate that the SBI groups' performance exceeded that of the GSI group on the Pennsylvania System of School Assessment measure. On the computation test, both groups made gains over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
923.
924.
Rena Helms-Park Author Vitae Paul Stapleton Author Vitae 《Computers and Composition》2006,23(4):444-461
The steady increase in the use of Web sites as sources in undergraduate research-based papers has raised concerns about the suitability of these reference materials for citation and about the ability of undergraduates to distinguish between appropriate and inappropriate sources in academic writing. While informal means of evaluating Web sites are in existence, there is a need for Web-source assessment criteria that not only focus on the use of these particular sources in introductory undergraduate writing programs but also closely match the requirements of faculty within a specific academic field. This paper identifies elements of a prototypical rating instrument for students in Humanities courses based on the results of a three-part survey of faculty members in a Humanities Department (N = 31) and highlights the divergence between criteria that faculty found crucial and those that many undergraduate students appear to be using in their Web-based research. 相似文献
925.
Phelps LeAdelle; McGrew Kevin S.; Knopik Susan N.; Ford Laurie 《Canadian Metallurgical Quarterly》2005,20(1):66
One hundred, forty-eight randomly selected children (grades three-five) were administered the WISC-III, WJ III Tests of Cognitive Abilities, WJ III Tests of Achievement, and seven research tests selected from the WJ III Diagnostic Supplement. The validity of the existing WISC-III and WJ III broad Cattell-Horn-Carroll (CHC) test classifications was investigated via the application of CHC-organized, broad-factor, cross-battery confirmatory factor analyses (CFA). Likewise, the validity of the WISC-III and WJ III narrow CHC ability classifications was investigated via the evaluation of a three-stratum hierarchical (narrow+broad+g) CHC CFA cross-battery model. The Tucker-Lewis Index, the Comparison Fit Index, and the Root Mean Square Error of Approximation evaluated the fit for the resulting models. All statistical values indicated good to excellent fit. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
926.
No authorship indicated 《Canadian Metallurgical Quarterly》1999,54(8):578a
The American Psychological Foundation (APF) Gold Medal Awards recognize distinguished and enduring records of accomplishments in 4 areas of psychology. The 1999 recipient of the Gold Medal Award for Life Achievement in the Practice of Psychology is Herbert J. Freudenberger. Freudenberger is cited for his exemplary professionalism as a psychologist and psychoanalyst dedicated to the alleviation of human suffering; for the sensitivity and conceptual genius that enabled him to establish the clinical construct of burnout; for his dedication to expanding our understanding of human behavior through theoretical contributions, teaching, and voluminous interdisciplinary and international publications; and for his innovative treatment of those afflicted with substance abuse problems. A citation, biography, and selected bibliography of Freudenberger's work are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
927.
No authorship indicated 《Canadian Metallurgical Quarterly》2001,56(8):582
The 2001 Gold Medal Award for Life Achievement in the Practice of Psychology was awarded to Herman Feifel. He is considered the father of the modern death movement. His efforts broke the entrenched taboo that had previously discouraged scientific study of death and dying and have earned him international acclaim. His work had influenced how psychologists think about death, treatment of the dying and bereaved, and how they view their own lives. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
928.
高等院校加强对下设院(部)的工作绩效考核,这是实施战略管理、提高教育质量的重要环节。本文以宁波工程学院为例,阐述了开展该项工作的必要性,选择了绩效考核方案的指标,揭示了工作绩效考核的基本特点和重要作用,对同类院校开展绩效考核工作具有启迪意义。 相似文献
929.
930.
目的 针对平板玻璃缺陷检测中灰尘干扰划痕、亮点检测的问题,提出一种基于全反射?掠入射组合照明的平板玻璃表面缺陷检测方法。方法 通过控制全反射光源和掠入射光源的发光时序,在相应发光时序内采集玻璃图像,根据缺陷在不同照明下的灰度纹理差异计算灰度、几何特征等一系列相对偏差特征,开发BP神经网络算法,实现玻璃表面灰尘和表面缺陷的检测。结果 BP神经网络在测试集上各类别预测的查准率、查全率均在90%以上,整体准确率达到97.2%。结论 全反射–掠入射组合照明成像系统结构简单,降低了玻璃图像中灰尘和内部点缺陷分类难度,有效减少灰尘和内部缺陷的误判。 相似文献