全文获取类型
收费全文 | 3063篇 |
免费 | 101篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 3165篇 |
出版年
2021年 | 29篇 |
2020年 | 25篇 |
2019年 | 31篇 |
2018年 | 37篇 |
2017年 | 47篇 |
2016年 | 46篇 |
2015年 | 51篇 |
2014年 | 73篇 |
2013年 | 217篇 |
2012年 | 100篇 |
2011年 | 135篇 |
2010年 | 113篇 |
2009年 | 99篇 |
2008年 | 115篇 |
2007年 | 114篇 |
2006年 | 112篇 |
2005年 | 88篇 |
2004年 | 107篇 |
2003年 | 97篇 |
2002年 | 72篇 |
2001年 | 53篇 |
2000年 | 59篇 |
1999年 | 62篇 |
1998年 | 89篇 |
1997年 | 77篇 |
1996年 | 61篇 |
1995年 | 48篇 |
1994年 | 55篇 |
1993年 | 55篇 |
1992年 | 47篇 |
1991年 | 25篇 |
1990年 | 27篇 |
1989年 | 24篇 |
1988年 | 35篇 |
1987年 | 32篇 |
1986年 | 41篇 |
1985年 | 41篇 |
1984年 | 43篇 |
1983年 | 32篇 |
1982年 | 29篇 |
1981年 | 33篇 |
1980年 | 27篇 |
1979年 | 27篇 |
1978年 | 33篇 |
1977年 | 44篇 |
1976年 | 41篇 |
1975年 | 29篇 |
1974年 | 30篇 |
1973年 | 19篇 |
1972年 | 23篇 |
排序方式: 共有3165条查询结果,搜索用时 31 毫秒
11.
Susskind Alex M.; Kacmar K. Michele; Borchgrevink Carl P. 《Canadian Metallurgical Quarterly》2003,88(1):179
The authors proposed and tested a model describing the relationship between customer service providers' perceptions and attitudes toward their service-related duties and their customers' perceptions of satisfaction with their service experiences. Results indicated that the perception of having standards for service delivery in an organization is strongly related to line-level employees' perceptions of support from coworkers and supervisors. Perceived support from coworker, was significantly related to service providers' customer orientation, whereas perceived support from supervisors showed a weaker relationship to a customer orientation. Ultimately, service providers' customer orientation was strongly related to customers' satisfaction with service. Finally, a set of post hoc analyses indicated that coworker and supervisory support explained a greater proportion of incremental variance in the model than did perceived organizational support alone. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
12.
The performance of ARQ systems can be improved by combining current and prior transmissions at the receiver. Two techniques
for combining outputs in a packet-based communication system are presented. In both techniques the fundamental unit of retransmission
is a packet, and the fundamental unit of combining is a codeword. The techniques are analyzed for a bursty channel and a system
that employs Reed–Solomon coding and bounded-distance errors-and-erasures decoding. Performance results show that the packet-combining
schemes provide significant gains in throughput and reductions in error probability when compared with a system that does
not employ combining.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
13.
14.
15.
16.
This study concerns how user training on newly introduced computer application programs is carried out. Questionnaire data from the computer managers of 265 Swedish companies were analysed. The results show that formal training, i.e., teacher-directed group instruction, and self-studies using instruction manuals represented nearly two-thirds of all reported training forms. For the most recently introduced program, classes (group instruction) with simultaneous computer exercises was the form of formal training that was nearly always used. When formal training was given it was compulsory in over half of the cases. However, substitutes for users attending a training course were only provided by the company in very few of these cases. The implications of these findings for effective user training are discussed. 相似文献
17.
Nabesna Glacier is one of the longest land-terminus mountain glaciers in North America. However, its flow has never been studied. We derived detailed motion patterns of Nabesna Glacier in winter and spring 1994–1996 from the synthetic aperture radar (SAR) images acquired by the European Remote Sensing satellites (ERS-1 and ERS-2) using interferometric SAR (InSAR) techniques. Special effort was made to assess the accuracy of the motion estimates, and remove data points with high uncertainty from the motion profiles, enabling us to obtain reliable glacier flow patterns along the highly curved main course of Nabesna Glacier. The results, covering 80 km of the 87 km main course of the glacier, were used to delineate four distinctive sections in terms of spatial and temporal variability of the glacier speed: (1) the upper section where glacier flow was apparently random both temporally and spatially presumably due to development of crevasses; (2) the upper-middle section with relatively steady flow around 0.27 to 0.4 m/day; (3) the middle section with a stable pattern of acceleration from 0.27–0.3 m/day to the maximum about 0.67–0.73 m/day, followed by a general deceleration to 0.17–0.33 m/day before reaching (4) the lower section where the glacier motion was generally slow yet highly variable although uncertainty in the estimation is high. Occurrence of the flow maximum, as well as many local maxima and minima at consistent locations over different periods suggests that the valley geometry affect the overall flow pattern. On top of this general trend, many small-scale temporal/spatial variations in the glacier flow patterns were observed along the glacier, especially in the lower sections. On average, the flow speeds were in the range of 0.3 to 0.7 m/day; however this lacks any measurements of summer flow speeds which are expected to be significantly higher. 相似文献
18.
19.
Abstract. Certification is one criterion that employers seek when hiring network professionals. Many employers assume a certified network professional is better able to manage networked resources than is a non-certified counterpart. Therefore, employers often offer a monetary premium to attract certified network professionals. By measuring end-user perceptions, the current study empirically assesses the popular industry assumption that certified network professionals are more adept managers of network resources than those individuals who are not certified network professionals. Analyses of a data derived from 299 end-users of 11 separate local area networks indicate no statistically significant difference exists between the capabilities of certified network professionals and non-certified network professionals. 相似文献
20.
Evidence is presented that bears on 9 hypotheses about the link between religion or spirituality and mortality, morbidity, disability, or recovery from illness. In healthy participants, there is a strong, consistent, prospective, and often graded reduction in risk of mortality in church/service attenders. This reduction is approximately 25% after adjustment for confounders. Religion or spirituality protects against cardiovascular disease, largely mediated by the healthy lifestyle it encourages. Evidence fails to support a link between depth of religiousness and physical health. In patients, there are consistent failures to support the hypotheses that religion or spirituality slows the progression of cancer or improves recovery from acute illness but some evidence that religion or spirituality impedes recovery from acute illness. The authors conclude that church/service attendance protects healthy people against death. More methodologically sound studies are needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献