全文获取类型
收费全文 | 5430篇 |
免费 | 678篇 |
国内免费 | 773篇 |
学科分类
工业技术 | 6881篇 |
出版年
2024年 | 36篇 |
2023年 | 92篇 |
2022年 | 146篇 |
2021年 | 124篇 |
2020年 | 133篇 |
2019年 | 111篇 |
2018年 | 117篇 |
2017年 | 135篇 |
2016年 | 156篇 |
2015年 | 187篇 |
2014年 | 300篇 |
2013年 | 282篇 |
2012年 | 426篇 |
2011年 | 450篇 |
2010年 | 393篇 |
2009年 | 429篇 |
2008年 | 449篇 |
2007年 | 504篇 |
2006年 | 432篇 |
2005年 | 436篇 |
2004年 | 348篇 |
2003年 | 300篇 |
2002年 | 214篇 |
2001年 | 163篇 |
2000年 | 94篇 |
1999年 | 69篇 |
1998年 | 55篇 |
1997年 | 38篇 |
1996年 | 36篇 |
1995年 | 24篇 |
1994年 | 9篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1966年 | 10篇 |
1965年 | 8篇 |
1964年 | 17篇 |
1963年 | 17篇 |
1962年 | 8篇 |
1961年 | 8篇 |
1960年 | 5篇 |
1959年 | 12篇 |
1958年 | 5篇 |
1956年 | 12篇 |
1955年 | 5篇 |
排序方式: 共有6881条查询结果,搜索用时 0 毫秒
1.
分析了河北冶金近期行业发展特别关注的几个问题:钢铁生产发展过快;产业结构缺陷,资源供应和环境压力。同时,文章从分析国内外市场形势和国家宏观政策形势入手,提出了河北冶金工业对产品结构调整,工艺装备调整和组织结构调整的必要性,任务和需注意的问题。 相似文献
2.
3.
陈恒庆 《冶金标准化与质量》2004,42(1):54-57
根据美国国家标准学会 (ANSI)理事会主席、ISO现任主席OliverR .Smoot在日本东京召开的国际标准化协议会上的讲演整理。 相似文献
4.
Mulcahy Nicholas J.; Call Josep; Dunbar Robin I. M. 《Canadian Metallurgical Quarterly》2005,119(1):23
Two important elements in problem solving are the abilities to encode relevant task features and to combine multiple actions to achieve the goal. The authors investigated these 2 elements in a task in which gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus) had to use a tool to retrieve an out-of-reach reward. Subjects were able to select tools of an appropriate length to reach the reward even when the position of the reward and tools were not simultaneously visible. When presented with tools that were too short to retrieve the reward, subjects were more likely to refuse to use them than when tools were the appropriate length. Subjects were proficient at using tools in sequence to retrieve the reward. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
This study provides a meta-analysis of research on the associations between relationship conflict, task conflict, team performance, and team member satisfaction. Consistent with past theorizing, results revealed strong and negative correlations between relationship conflict, team performance, and team member satisfaction. In contrast to what has been suggested in both academic research and introductory textbooks, however, results also revealed strong and negative (instead of the predicted positive) correlations between task conflict, team performance, and team member satisfaction. As predicted, conflict had stronger negative relations with team performance in highly complex (decision making, project, mixed) than in less complex (production) tasks. Finally, task conflict was less negatively related to team performance when task conflict and relationship conflict were weakly, rather than strongly, correlated. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
7.
Verbrugge Sara; Dieussaert Kristien; Schaeken Walter; Van Belle William 《Canadian Metallurgical Quarterly》2004,58(2):106
Evidence from reasoning tasks shows that promises and threats both tend to receive biconditional interpretations. They also both display high speaker control. On the face of it, the only difference seems to be the positive or negative signing of the consequent. In a promise, the speaker tries to persuade the hearer to do something by holding out the prospect of a particular reward; in a threat, the speaker tries to refrain the hearer from doing something by holding out the prospect of a particular punishment. This paper investigates the respects in which conditional promises and threats differ further by means of an inference task. The credibility of the consequent was manipulated in order to examine whether the acceptability ratings of inferences based on promises and on threats would be equally affected. The results of the inference task and an analysis of the reasons people give for their answers suggest that the credibility of promises is less affected by the use of excessive consequents than the credibility of threats. In other words, promise remains debt, whereas threat is another matter. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
介绍了一种用可编程控制器(PLC)实现捆扎机自动控制的设计方案,详细地介绍了设计过程,给出了完整的程序流程图和部分控制程序。 相似文献
9.
The purpose of this study was to examine predictors and consequences of spouses' involvement in each others' strategies for pursuing important personal goals called life tasks. Husbands and wives within 39 short- and long-term marriages described five life tasks and provided appraisals of whether each was shared with their spouse. Participants later completed 14 consecutive diary entries recording daily life task pursuit strategies, the extent of spouse involvement in each, and measures of positive and negative affect. Results indicated that interdependence in life task appraisals prospectively predicted greater spouse involvement, and greater spouse involvement was associated with more positive affect for that day. Life task appraisals may provide avenues for understanding couples' strategies for dealing with goals or stressors and how those strategies affect mood. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
10.
Multiple forms of a symbol-digit substitution task were used to provide a componential analysis of age differences in coding task performance. The results demonstrated age differences in feature encoding, memory, and visual search. A 2nd experiment was conducted with young adults to investigate a sensory deficit as a locus of age differences. The spatial contrast sensitivity deficit of older adults was simulated on forms by applying a digital filter. Persons in the age-simulated contrast condition performed worse than those in the normal contrast condition. The stimulus degradation effect was linked to visual search speed. The study illustrates the utility of componential analysis and offers direct support for the hypothesis that sensory deficits affect performance on tasks used to assess intelligence (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献