全文获取类型
收费全文 | 1761篇 |
免费 | 83篇 |
国内免费 | 25篇 |
专业分类
电工技术 | 20篇 |
技术理论 | 1篇 |
综合类 | 413篇 |
化学工业 | 48篇 |
金属工艺 | 10篇 |
机械仪表 | 34篇 |
建筑科学 | 400篇 |
矿业工程 | 35篇 |
能源动力 | 9篇 |
轻工业 | 182篇 |
水利工程 | 34篇 |
石油天然气 | 17篇 |
无线电 | 46篇 |
一般工业技术 | 110篇 |
冶金工业 | 306篇 |
原子能技术 | 1篇 |
自动化技术 | 203篇 |
出版年
2024年 | 2篇 |
2023年 | 23篇 |
2022年 | 30篇 |
2021年 | 44篇 |
2020年 | 45篇 |
2019年 | 34篇 |
2018年 | 32篇 |
2017年 | 32篇 |
2016年 | 47篇 |
2015年 | 50篇 |
2014年 | 115篇 |
2013年 | 95篇 |
2012年 | 127篇 |
2011年 | 109篇 |
2010年 | 108篇 |
2009年 | 117篇 |
2008年 | 114篇 |
2007年 | 85篇 |
2006年 | 110篇 |
2005年 | 111篇 |
2004年 | 100篇 |
2003年 | 72篇 |
2002年 | 85篇 |
2001年 | 56篇 |
2000年 | 29篇 |
1999年 | 21篇 |
1998年 | 9篇 |
1997年 | 9篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1964年 | 4篇 |
1961年 | 4篇 |
1960年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
1957年 | 3篇 |
1956年 | 2篇 |
1955年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有1869条查询结果,搜索用时 15 毫秒
61.
62.
Facebook is a well-known computer-mediated communication platform considered popular among adolescents and young adults. New media scholars have coined the term “intensity of Facebook use” (IFU) for the concept that measures the emotional and affective attitude towards Facebook use among young people. IFU is an important service use concept that has been positively linked with the different psychosocial outcomes of student well-being. However, only a limited amount of the prior literature has investigated the relationship between IFU and different Facebook uses and gratifications (U&G). The existing literature suggests inconsistent findings with a sole emphasis on young adults. To address these gaps, the present study has investigated the differential role of different Facebook U&G among adolescents and young adults in predicting IFU. A total of three cross-sectional data sets (N = 373, 107, 105) represented adolescents and university-attending young-adult Facebook users. The study results suggest that process U&G do and content U&G do not play any significant role in predicting IFU. Adolescents and young adults differ in their sought Facebook U&G. In addition to this, cultural differences were observed in the sought Facebook U&G and their differential role in predicting IFU. 相似文献
63.
Vaish Amrisha; Carpenter Malinda; Tomasello Michael 《Canadian Metallurgical Quarterly》2011,47(5):1248
Displaying guilt after a transgression serves to appease the victim and other group members, restore interpersonal relationships, and indicate the transgressors' awareness of and desire to conform to the group's norms. We investigated whether and when young children are sensitive to these functions of guilt displays. In Study 1, after 4- and 5-year-old children watched videos of transgressors either displaying guilt (without explicitly apologizing) or not displaying guilt, 5-year-olds appropriately inferred that the victim would be madder at the unremorseful transgressor and would prefer the remorseful transgressor. They also said that they would prefer to interact with the remorseful transgressor, judged the unremorseful transgressor to be meaner, and, in a distribution of resources task, gave more resources to the remorseful transgressor. The 4-year-olds did not draw any of these inferences and distributed the resources equally. However, Study 2 showed that 4-year-olds were able to draw appropriate inferences about transgressors who explicitly apologized versus those who did not apologize. Thus, 4-year-olds seem to know the appeasement functions that explicit apologies serve but only when children have reached the age of 5 years do they seem to grasp the emotions that apologies stand for, namely, guilt and remorse, and the appeasement functions that displaying these emotions serve. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
64.
Internet use and access in the UK has increased rapidly in the last decade, with the concept of ‘information superhighway’ recognised as an axiom of Internet technology. Despite this, few studies have sought to investigate the incidence of use of the Internet as an advice resource outside of the health information arena. With an increasing impetus in the public sector towards the provision of online delivery mechanisms for civic orientated activities, including advice provision, it is timely to better understand the appropriateness of online advice seeking. Focusing on young people aged between 18 and 24 years, we investigated how much the Internet was used to obtain information about everyday problems with a legal dimension, who used it, how it was used and how successful respondents were in searching for information online. Data were extracted from a large-scale household survey of adults’ experience of problems with a legal dimension conducted across England and Wales (10,512 adult respondents). Results revealed significant growth in the use of the Internet to obtain information about such problems, rising from 4% in 2001 to around 18% in 2008. The responses of the 18-24 year olds to the survey illustrated that despite having comparatively high levels of Internet access, this age group utilised it to a lesser degree than similarly ‘connected’ age cohorts, and were less successful when doing so. This study highlights aspects of the second digital divide, going beyond access to explore use and outcomes of use. Implications for the future of the Internet in providing information and advice for young people, are discussed. 相似文献
65.
Stein Catherine H.; Abraham Kristen M.; Bonar Erin E.; Leith Jaclyn E.; Kraus Shane W.; Hamill Alexis C.; Gumber Shinakee; Hoffmann Erica; Fogo Wendy R. 《Canadian Metallurgical Quarterly》2011,25(3):449
The present intergenerational study examined the perceived impact of the recent U.S. economic crisis on a sample of 68 young adult–parent dyads. The relative contribution of perceived economic pressure, reports of adult child–parent relationship quality, and concerns about the economic future in accounting for variation in self-reports of psychological distress for adult children and their middle-aged parents were examined. Parents' concerns about their children's economic future accounted for variation in their reports of anxiety and depressed mood above and beyond that of perceived economic pressures and their views of the parent–child relationship. In contrast, for young adults, reports of personal economic pressure were generally related to self-reported anxiety and depressed mood. Implications of findings for research and practice are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
66.
针对某大型商业综合体中庭商业空间防火分区面积过大、部分疏散楼梯不能直通室外及疏散距离过长等消防设计问题,在分析现有消防设计的基础上,利用消防安全工程学原理,采用性能化的设计方法,提出解决方案,如限制中庭火灾荷载,店铺采用防火单元设计,可为同类建筑的消防设计提供参考。 相似文献
67.
68.
如何营造出具有地域文化特色、生态型的行政中心景观,满足时代对行政中心开放、亲民、高效、廉洁的环境要求,是本文阐述的重点。文章结合湘乡市行政中心景观规划设计,力求在理论上较系统地对其进行阐述。 相似文献
69.
70.
Ray Forrest 《Housing Studies》2018,33(1):1-17
Young people across many societies face growing problems in making the transition from the parental home to independent living. Rising house prices and the lack of affordable alternatives to home ownership is most commonly blamed. This paper explores these issues in relation to young people in Hong Kong. The paper argues that the housing question in Hong Kong has distinct local characteristics and cannot be disconnected from wider political and economic tensions. It also shows that the housing choices and views of young people are shaped by more than issues of cost and access. The paper draws on a unique data-set which explores the attitudes and expectations with regard to housing among young people in Hong Kong. Addressing the housing problem is widely regarded as a political priority and essential to maintain social cohesion. However, political imperatives and economic interests are pulling in different directions. 相似文献