全文获取类型
收费全文 | 2073篇 |
免费 | 95篇 |
国内免费 | 100篇 |
专业分类
电工技术 | 76篇 |
综合类 | 154篇 |
化学工业 | 383篇 |
金属工艺 | 53篇 |
机械仪表 | 20篇 |
建筑科学 | 159篇 |
矿业工程 | 46篇 |
能源动力 | 30篇 |
轻工业 | 198篇 |
水利工程 | 26篇 |
石油天然气 | 13篇 |
武器工业 | 7篇 |
无线电 | 84篇 |
一般工业技术 | 175篇 |
冶金工业 | 505篇 |
原子能技术 | 18篇 |
自动化技术 | 321篇 |
出版年
2024年 | 4篇 |
2023年 | 35篇 |
2022年 | 42篇 |
2021年 | 74篇 |
2020年 | 60篇 |
2019年 | 69篇 |
2018年 | 50篇 |
2017年 | 56篇 |
2016年 | 62篇 |
2015年 | 51篇 |
2014年 | 86篇 |
2013年 | 124篇 |
2012年 | 106篇 |
2011年 | 154篇 |
2010年 | 111篇 |
2009年 | 117篇 |
2008年 | 100篇 |
2007年 | 126篇 |
2006年 | 177篇 |
2005年 | 146篇 |
2004年 | 99篇 |
2003年 | 80篇 |
2002年 | 77篇 |
2001年 | 81篇 |
2000年 | 23篇 |
1999年 | 16篇 |
1998年 | 22篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1961年 | 2篇 |
1960年 | 1篇 |
1959年 | 2篇 |
1958年 | 3篇 |
1957年 | 1篇 |
1955年 | 1篇 |
1954年 | 2篇 |
排序方式: 共有2268条查询结果,搜索用时 46 毫秒
101.
102.
López Steven R.; Lara Ma. del Carmen; Kopelowicz Alex; Solano Susana; Foncerrada Hector; Aguilera Adrian 《Canadian Metallurgical Quarterly》2009,77(4):763
The authors developed and tested a 35-min psychoeducational program with the goal of increasing Spanish-speaking persons’ literacy of psychosis. The program uses popular cultural icons derived from music, art, and videos, as well as a mnemonic device—La CLAve (The Clue)—to increase (a) knowledge of psychosis, (b) efficacy beliefs that one can identify psychosis in others, (c) attributions to mental illness, and (d) professional help-seeking. Assessments were conducted before and after administering the program to both community residents (n = 57) and family caregivers of persons with schizophrenia (n = 38). For community residents, the authors observed increases across the 4 domains of symptom knowledge, efficacy beliefs, illness attributions, and recommended help-seeking. For caregivers, increases were observed in symptom knowledge and efficacy beliefs. La CLAve is a conceptually informed psychoeducational tool with a developing empirical base aimed at helping Spanish-speaking Latinos with serious mental illness obtain care in a timely manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
Gano-Overway Lori A.; Newton Maria; Magyar T. Michelle; Fry Mary D.; Kim Mi-Sook; Guivernau Marta R. 《Canadian Metallurgical Quarterly》2009,45(2):329
Understanding what factors influence positive youth development has been advocated by youth development researchers (P. L. Benson, 2006; J. S. Eccles & J. A. Gootman, 2002). Consequently, the purpose of this study was to examine whether perceptions of a caring youth sport context influenced prosocial and antisocial behavior through efficacy-related beliefs, that is, positive and negative affective self-regulatory efficacy (ASRE) and empathic self-efficacy (ESE). Multiethnic youths taking part in summer sport programs (N = 395) completed a questionnaire that measured perceptions of the caring climate, ESE, ASRE, and social behavior. Structural equation modeling was used to test whether ASRE and ESE mediated the relationship between caring and social behaviors. Findings revealed that perceptions of caring positively predicted ASRE and ESE. In turn, positive ASRE positively predicted ESE. Prosocial behaviors were positively linked to ESE, whereas antisocial behaviors were negatively predicted by positive ASRE. The results suggest that caring influences prosocial and antisocial behavior because such contexts develop youths' ability to monitor, manage, and control positive affect, which in turn enhances their belief in their ability to empathize. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
104.
C. Ruamrak N. Lourith† S. Natakankitkul‡ 《International journal of cosmetic science》2009,31(1):41-46
Acne vulgaris impairs the appearance of an individual and causes psychological irritation. Inflammatory acne lesion is caused by multifactor incorporates in each step of acne pathogenesis. In an attempt to archive inflammatory lesion treatment with the promise of prevention of acne vulgaris, randomized and double-blind studies on the comparison of the efficacies of topical formulations containing 5% sodium ascorbyl phosphate (SAP) and 0.2% retinol, separately as well as in combination application, were conducted. The resulting data showed that SAP reduced the inflammatory lesion by 20.14% and 48.82% within 4 and 8 weeks respectively. Application of the formulation containing retinol slightly improved the treatment efficacy as the lesion reduced by 21.79% and 49.50% after 4 and 8 weeks respectively. The combination treatment significantly reduced the inflammatory lesion by 29.28% after 4 weeks and 63.10% after 8 weeks of application. The most effective treatment was by using the combination of 5% SAP and 0.2% retinol, which incorporated the synergistic effects on lipid peroxidation and sebaceous gland function in addition to the enhancement of SAP permeability by the desquamation of stratum corneum influenced by retinol, keratin plug removal and anti-inflammatory effect of retinol. This study promises for the development of cosmetic products to overcome aesthetic and psychological problems caused by acne vulgaris. 相似文献
105.
陈同福 《广东工业大学学报》1994,(3)
提出在社会主义市场经济条件下,高校技术物资采购中的反季节策略.并讨论了该策略的适用条件、适用范围和应用方法. 相似文献
106.
De Cremer David; van Knippenberg Daan; van Dijke Marius; Bos Arjan E. R. 《Canadian Metallurgical Quarterly》2006,10(3):233
In the present research, we examine whether leader's self-sacrifice positively influences followers' self-esteem and whether followers' identification with the collective plays a role in this process. It was predicted that leader self-sacrifice would influence followers' self-esteem, but particularly so when followers exhibited strong (vs. weak) collective identification. Results from an organizational survey showed that leader self-sacrifice and collective identification interacted in predicting follower self-esteem, such that followers' self-esteem was higher when they identified strongly with the collective and when the leader was self-sacrificial (vs. self-benefiting). An experimental scenario study replicated this interactive effect between collective identification and leader's self-sacrifice on followers' self-esteem and also showed that this effect was (at least partly) mediated by followers' perceptions of whether the leader respected and valued the group. Implications with respect to the relationship between self-sacrifice and self-esteem are outlined, and possible integrations of leader self-sacrifice, identity, and empowerment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
Many studies have found smokers' quit history to correlate with quitting smoking, but little is known about the psychological processes explaining this relationship. This study uses the integrative model of behavioral prediction to examine how quit history affects quit intention. Data from 3,428 Dutch smokers demonstrate that quit history affects (a) beliefs about quitting and (b) the degree to which self-efficacy predicts quit intention. It seems that a relatively unsuccessful history of prior quit attempts reduces self-efficacy over quitting and strengthens the relationship of self-efficacy with the intention to quit. The results are used to call for more process-oriented research in order to advance our understanding of the relationship between quit history and quit intention. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
108.
109.
Metallochloronitrides are layered conductors that have recently been found to superconduct at critical temperatures up to T
c 26 K. It is known that the electron–phonon interaction is small in these systems, so that the conventional pairing mechanism through exchange of phonons is unable to provide for such high T
cs. We show that the dominant contribution to the pairing interaction in these materials comes from the exchange of low-energy collective modes, specific to layered conductors. The existence of such acoustic plasmons results from the incomplete screening of the Coulomb interaction perpendicular to the conducting planes which expresses itself in the dynamical nature of the screened Coulomb interaction. 相似文献
110.
节能泡——一种高效卤钨灯 总被引:1,自引:0,他引:1
为应对全球气候变化,推进节能减排,世界主要国家纷纷出台淘汰白炽灯的计划。中国也即将推出逐步淘汰白炽灯路线图。后白炽灯时代,谁主沉浮?本文介绍了节能泡的相关性能指标,比较了几种白炽灯替代光源的优缺点,说明节能泡仍具有强大的生命力,并阐述了节能泡的发展方向。 相似文献