全文获取类型
收费全文 | 501篇 |
免费 | 29篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 2篇 |
综合类 | 23篇 |
化学工业 | 3篇 |
金属工艺 | 2篇 |
机械仪表 | 3篇 |
建筑科学 | 5篇 |
矿业工程 | 3篇 |
轻工业 | 32篇 |
水利工程 | 1篇 |
无线电 | 11篇 |
一般工业技术 | 28篇 |
冶金工业 | 314篇 |
自动化技术 | 117篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 12篇 |
2016年 | 11篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 16篇 |
2012年 | 19篇 |
2011年 | 35篇 |
2010年 | 35篇 |
2009年 | 34篇 |
2008年 | 29篇 |
2007年 | 27篇 |
2006年 | 38篇 |
2005年 | 40篇 |
2004年 | 39篇 |
2003年 | 36篇 |
2002年 | 26篇 |
2001年 | 18篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1993年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 4篇 |
1965年 | 4篇 |
1964年 | 6篇 |
1963年 | 3篇 |
1962年 | 3篇 |
1961年 | 3篇 |
1960年 | 5篇 |
1959年 | 2篇 |
1958年 | 4篇 |
1957年 | 2篇 |
1956年 | 3篇 |
1955年 | 3篇 |
1954年 | 4篇 |
排序方式: 共有544条查询结果,搜索用时 15 毫秒
41.
Parker Janat Fraser; Bahrick Lorraine E.; Fivush Robyn; Johnson Paulette 《Canadian Metallurgical Quarterly》2006,12(3):142
The effects of stress on mothers' recall for a major hurricane were studied. Stress was objectively defined as low, moderate, or high according to the severity of home damage. This study of 96 mothers was conducted concurrently with L. E. Bahrick, J. F. Parker, R. Fivush, and M. Levitt (1998), allowing the authors to compare child and adult recall as a function of the same stressor. There was a quadratic relationship between storm severity and total recall for adults, similar to their children. Mothers' recall increased from low to moderate severity, but recall at moderate severity did not differ from high severity. These findings help clarify the effects of stress on the amount and type of information adults recall in retrospective accounts of naturalistic, temporally extended events. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
42.
自适应推荐算法在电子超市个性化服务系统中的应用研究 总被引:1,自引:0,他引:1
为了满足电子超市中用户的个性化的服务需求,提出并实现了一种基于支持向量机的自适应推荐算法。首先,将用户模型按照层次化方式组织成领域信息和原子需求信息,考虑多用户同类信息需求。采用支持向量机对领域信息节点中的原子需求信息进行分类协同推荐,然后在针对每一领域信息节点中的原子信息需求进行基于内容的过滤。该算法克服了分别采用协同推荐和基于内容的推荐单一方法的缺点,大大提高了信息的查准率和查全率,尤其适合大规模用户群的信息推荐。该算法用于基于电子超市的个性化推荐服务系统(PRSSES)中,结果表明是有效的。 相似文献
43.
David McSherry 《Artificial Intelligence Review》2002,18(3-4):309-341
Recommender systems for helping users to selectfrom available products or services areincreasingly common in electronic commerce. Typically in case-based reasoning (CBR)approaches to product recommendation, the itemsrecommended are those that are most similar toa target query representing the elicitedrequirements of the user. Usually in practice,the user is required to specify a singlepreferred value for each attribute in thequery. However, we argue that a more flexibleapproach to requirements elicitation isnecessary to meet the needs of different users,ranging from those who know exactly what theyare looking for to those whose requirements arevague in the extreme. We show how the standardapproach to similarity-based retrieval can begeneralised to support queries in which theuser can enter any number of preferred valuesof a selected attribute, and examine thepotential benefits of the approach. 相似文献
44.
Ss were shown tachistoscopically-presented word stimuli to test the distinction between the perceptual processes of registration (what could be called physiological or sensory threshold) and awareness (or the cognitive threshold). The presentation consisted of a stimulus word followed by series of words associated to the stimulus word either in terms of meaning or structural resemblance. Recall of words presented subliminally or supraliminally was facilitated with degree of awareness of actual stimulus word; with greater awareness of the word, associational recall was for words that structurally resembled S word; without awareness, recall was determined by associative meaning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
45.
评价一个信息检索系统的标准是该系统在多大程度上满足用户的能力。文中从传统的评价信息检索系统的两大标准———计算查全率和查准率的公式出发,结合实际情况,考虑检索结果相关性是一个模糊的概念,为了对这个模糊的概念以客观的度量,应用模糊集的方法对传统的查全率和查准率的公式进行了两种修改。一种修改是在每篇文档对总的查全率和查准率的影响相同时进行的,而第二种修改则是在每一类文档对总的查全率和查准率的影响相同时进行的。这两种修改是对传统的基于二值相关性的检索评价系统的有效扩充。 相似文献
46.
Increases over birth cohorts in psychometric abilities may impact effects of aging. Data from 2 cohorts of the Long Beach Longitudinal Study, matched on age but tested 16 years apart, were modeled over ages 55-87 to test the hypothesis that the more fluid abilities of reasoning, list and text recall, and space would show larger cohort differences than vocabulary. This hypothesis was confirmed. At age 74, average performance estimates for people from the more recently born cohort were equivalent to those of people from the older cohort when they were up to 15 years younger. This finding suggests that older adults may perform like much younger ones from the previous generation on fluid measures, indicating higher levels of abilities than expected. This result could have major implications for the expected productivity of an aging workforce as well as for the quality of life of future generations. However, cohort improvements did not mitigate age declines. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
47.
48.
通过LuceneAPI实现对PDF文档的一次全文检索,为了更精确地定位搜索关键词,设计并实现了一种新的二次索引算法,该二次索引带有关键词的页码、坐标及其上下文等信息。利用该二次索引可将检索结果定位到PDF文档的具体页,然后在页面上标示出关键字的具体位置,使对PDF文档的二次检索达到了类似GoogleBook的图书检索效果。系统测试结果说明系统具有良好检索性能,有较高的查全率和查准率,能够满足用户快速检索的需求。系统作为西安市数字方志全文检索平台投入使用已有2年,取得了较好的应用成果。 相似文献
49.
In a serial recall task, the Hebb repetition effect occurs when recall performance improves for a sequence repeated throughout the experimental session. This phenomenon has been replicated many times. Nevertheless, such cumulative learning seldom leads to perfect recall of the whole sequence, and errors persist. Here the authors report evidence that there is another side to the Hebb repetition effect that involves learning errors produced in a repeated sequence. A learning measure based on past recalls (correct or incorrect) shows that the probability of a given response increases with the number of prior occurrences of that response. The pattern of results reveals another manifestation of the Hebb repetition effect and speaks to the nature of implicit learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
Polyn Sean M.; Erlikhman Gennady; Kahana Michael J. 《Canadian Metallurgical Quarterly》2011,37(3):766
In recalling a set of previously experienced events, people exhibit striking effects of recency, contiguity, and similarity: Recent items tend to be recalled best and first, and items that were studied in neighboring positions or that are similar to one another in some other way tend to evoke one another during recall. Effects of recency and contiguity have most often been investigated in tasks that require people to recall random word lists. Similarity effects have most often been studied in tasks that require people to recall categorized word lists. Here we examine recency and contiguity effects in lists composed of items drawn from 3 distinct taxonomic categories and in which items from a given category are temporally separated from one another by items from other categories, all of which are tested for recall. We find evidence for long-term recency and for long-range contiguity, bolstering support for temporally sensitive models of memory and highlighting the importance of understanding the interaction between temporal and semantic information during memory search. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献