全文获取类型
收费全文 | 6065篇 |
免费 | 125篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 63篇 |
综合类 | 6篇 |
化学工业 | 1270篇 |
金属工艺 | 81篇 |
机械仪表 | 90篇 |
建筑科学 | 351篇 |
矿业工程 | 64篇 |
能源动力 | 134篇 |
轻工业 | 414篇 |
水利工程 | 41篇 |
石油天然气 | 57篇 |
无线电 | 375篇 |
一般工业技术 | 739篇 |
冶金工业 | 1706篇 |
原子能技术 | 42篇 |
自动化技术 | 764篇 |
出版年
2021年 | 82篇 |
2020年 | 44篇 |
2019年 | 58篇 |
2018年 | 61篇 |
2017年 | 90篇 |
2016年 | 93篇 |
2015年 | 78篇 |
2014年 | 83篇 |
2013年 | 415篇 |
2012年 | 149篇 |
2011年 | 199篇 |
2010年 | 161篇 |
2009年 | 184篇 |
2008年 | 183篇 |
2007年 | 225篇 |
2006年 | 182篇 |
2005年 | 189篇 |
2004年 | 153篇 |
2003年 | 166篇 |
2002年 | 145篇 |
2001年 | 126篇 |
2000年 | 94篇 |
1999年 | 127篇 |
1998年 | 156篇 |
1997年 | 120篇 |
1996年 | 131篇 |
1995年 | 98篇 |
1994年 | 108篇 |
1993年 | 95篇 |
1992年 | 85篇 |
1991年 | 54篇 |
1990年 | 112篇 |
1989年 | 92篇 |
1988年 | 87篇 |
1987年 | 91篇 |
1986年 | 86篇 |
1985年 | 90篇 |
1984年 | 88篇 |
1983年 | 73篇 |
1982年 | 83篇 |
1981年 | 69篇 |
1980年 | 61篇 |
1979年 | 87篇 |
1978年 | 76篇 |
1977年 | 72篇 |
1976年 | 79篇 |
1975年 | 64篇 |
1974年 | 75篇 |
1973年 | 61篇 |
1972年 | 42篇 |
排序方式: 共有6197条查询结果,搜索用时 15 毫秒
1.
2.
3.
Many models of spoken word recognition posit the existence of lexical and sublexical representations, with excitatory and inhibitory mechanisms used to affect the activation levels of such representations. Bottom-up evidence provides excitatory input, and inhibition from phonetically similar representations leads to lexical competition. In such a system, long words should produce stronger lexical activation than short words, for 2 reasons: Long words provide more bottom-up evidence than short words, and short words are subject to greater inhibition due to the existence of more similar words. Four experiments provide evidence for this view. In addition, reaction-time-based partitioning of the data shows that long words generate greater activation that is available both earlier and for a longer time than is the case for short words. As a result, lexical influences on phoneme identification are extremely robust for long words but are quite fragile and condition-dependent for short words. Models of word recognition must consider words of all lengths to capture the true dynamics of lexical activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
Systematic assessment of anger among people with developmental disabilities has been lacking, especially for hospital inpatients. Reliability and validity of anger self-report psychometric scales were investigated with 129 male patients, mostly forensic. Anger prevalence and its relationship to demographic, cognitive, and personality variables and to hospital assaultive behavior were examined. High internal and intermeasure consistency, and some concurrent validity with staff ratings, were found. Retrospective validity regarding physically assaultive behavior in the hospital was obtained. Hierarchical regressions revealed that patient-reported anger was a significant predictor of assaults postadmission, controlling for age, length of stay, IQ, violence offense history, and personality variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
Arthur W. Westerberg 《Computers & Chemical Engineering》1985,9(5):421-429
The last dozen years have produced almost 50 English language articles on the synthesis of separation systems [1]. Most work has considered separating a single relatively ideal mixture into sharply split, usually pure-component products using systems of single-feed, two-product distillation columns. Of late, the work has considered heat-integrating these columns to reduce energy consumption. Present research will very likely produce valuable results for nonsharp separations.Earlier approaches developed both algorithmic- and heuristic-based tree search algorithms for discovering the better systems of non-heat-integrated columns. New results permit the design of heat-integrated systems.The paper highlights the above developments. 相似文献
6.
Hannes Verlinde Martine De Cock Raymond Boute 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2006,36(3):679-684
As opposed to quantitative association rule mining, fuzzy association rule mining is said to prevent the overestimation of boundary cases, as can be shown by small examples. Rule mining, however, becomes interesting in large databases, where the problem of boundary cases is less apparent and can be further suppressed by using sensible partitioning methods. A data-driven approach is used to investigate if there is a significant difference between quantitative and fuzzy association rules in large databases. The influence of the choice of a particular triangular norm in this respect is also examined. 相似文献
7.
The article proposes a theoretical framework in which moral reasoning about mediated crime and punishment is defined and combined with existing, affect-driven entertainment theory to yield an integrated theory of enjoyment. The authors analyze how crime dramas serve as statements about justice and then address how moral deliberation about the propriety of those statements impacts enjoyment. The authors report research findings to support the analysis of cognitive processing during crime dramas distinct from affective processing. The article also suggests future means by which the integrated theory of enjoyment can be examined. 相似文献
8.
Norris Fran H.; Murphy Arthur D.; Baker Charlene K.; Perilla Julia L.; Rodriguez Francisco Gutiérrez; Rodriguez José de Jesús Gutiérrez 《Canadian Metallurgical Quarterly》2003,112(4):646
Prevalence rates of trauma and posttraumatic stress disorder (PTSD) were estimated from a probability sample of 2,509 adults from 4 cities in Mexico. PTSD was assessed according to Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994) criteria using the Composite International Diagnostic Interview (CIDI; WHO, 1997). Lifetime prevalence of exposure and PTSD were 76% and 11.2%, respectively. Risk for PTSD was highest in Oaxaca (the poorest city), persons of lower socioeconomic status, and women. Conditional risk for PTSD was highest following sexual violence, but nonsexual violence and traumatic bereavement had greater overall impact because of their frequency. Of lifetime cases, 62% became chronic; only 42% received medical or professional care. The research demonstrates the importance of expanding the epidemiologic research base on trauma to include developing countries around the world. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
Values of D0 /δ and Q for grain-boundary diffusion, derived from published studies of normal grain growth in Al2 O3 , BeO, CaO, MgO, SiO2 , and CaSiO3 , are fit by the linear compensation equation log D0 /δ=0.03170Q -7.6792 (r2 =0.9384). Comparison of grain-boundary diffusion coefficients derived from grain growth in oxides with those obtained by direct experimental measurement suggests that the kinetics of normal grain growth are controlled by grain-boundary diffusion of oxygen. 相似文献
10.
In this paper we shall review the main appraches to nonmonotonic reasoning which we classify from the perspective of their underlying logical settings as classical, intuitionistic, three-valued/partial models, and conditional. We shall be placing special emphasis on some of the prominent approaches. We shall also give hints on potential future directions and emphasize that more theoretical work is still needed before a move to application is made. 相似文献