首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   322篇
  免费   20篇
工业技术   342篇
  2023年   1篇
  2022年   3篇
  2021年   11篇
  2020年   8篇
  2019年   4篇
  2018年   14篇
  2017年   12篇
  2016年   13篇
  2015年   10篇
  2014年   21篇
  2013年   31篇
  2012年   13篇
  2011年   18篇
  2010年   14篇
  2009年   13篇
  2008年   14篇
  2007年   11篇
  2006年   12篇
  2005年   11篇
  2004年   8篇
  2003年   17篇
  2002年   10篇
  2001年   8篇
  2000年   5篇
  1999年   6篇
  1998年   6篇
  1997年   8篇
  1996年   5篇
  1995年   1篇
  1994年   4篇
  1993年   1篇
  1992年   3篇
  1990年   2篇
  1989年   2篇
  1986年   3篇
  1985年   2篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1980年   4篇
  1979年   1篇
  1978年   2篇
  1976年   2篇
  1975年   1篇
  1909年   1篇
排序方式: 共有342条查询结果,搜索用时 31 毫秒
21.
A system for assisting in microneurosurgical training and for delivering interactive mixed reality surgical experience live was developed and experimented in hospital premises. An interactive experience from the neurosurgical operating theater was presented together with associated medical content on virtual reality eyewear of remote users. Details of the stereoscopic 360‐degree capture, surgery imaging equipment, signal delivery, and display systems are presented, and the presence experience and the visual quality questionnaire results are discussed. The users reported positive scores on the questionnaire on topics related to the user experience achieved in the trial.  相似文献   
22.
TiO2‐supported gold species were prepared via the deposition‐precipitation route, with conservation of the initial speciation by freeze‐drying. The structural and electronic properties of the Au species were investigated by X‐ray absorption spectroscopy, electron microscopy, and IR spectroscopy of adsorbed CO in four states. Exclusively AuIII was deposited on the TiO2 surface in patches ranging from isolated Au ions to three‐dimensional clusters. This paper illustrates in detail the unique contributions of all characterization techniques to this structural model.  相似文献   
23.
International Journal of Control, Automation and Systems - This paper is concerned with the problem of finding a time-optimal velocity profile along the predefined path for static formations of...  相似文献   
24.
Fida El Chami  Toni Sayah 《Calcolo》2010,47(3):169-192
In this paper we study the time dependent Stokes problem with some different boundary conditions. We establish a decoupled variational formulation into a system of velocity and a Poisson equation for the pressure. Hence, the velocity is approximated with curl conforming finite elements in space and Euler scheme in time and the pressure with standard continuous elements in space and Euler scheme in time. Finally, we establish optimal a priori and a posteriori estimates.  相似文献   
25.
Although siblings are thought to be influential in child development, little is known about the influence of sibling status on the health of older adults. Using structural equation modeling, the authors created and tested a series of models with data from a sample (N = 3,968) of 1957 high school graduates from the Wisconsin Longitudinal Study. The results indicated that socioeconomic status of origin, adolescent aptitude, and educational attainment did have significant total effects on health in later life, but sibling status did not. Adults who grew up in families of higher socioeconomic status and who had greater aptitude in high school attained more education, and this advantage, in turn, led to better health in later life. Although the final model was cross-validated, it was not equally plausible for men and women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
26.
We have developed a multifocal optical fluorescence correlation spectroscopy system for parallel flow analyses. Multifocal excitation was made possible through a 4 x 1 diffractive optical fan-out element, which produces uniform intensity in all four foci. Autocorrelation flow analyses inside a 20 microm x 20 microm square microchannel, with the 4 x 1 fan-out foci perpendicular to the flow direction, made it possible to monitor different flows in all four foci simultaneously. We were able to perform cross-correlation flow analyses by turning the microstructure, thereby having all four foci parallel to the direction of flow. Transport effects of the diffusion as a function of flow and distance could then also be studied.  相似文献   
27.
Abstract— Color breakup is an artifact perceivable on field‐sequential‐color (FSC) displays, both in stationary and in moving images. In this work, a unique device and a method for measuring color breakup on stationary images is proposed. Rotating the field of view of a high‐speed measurement camera in milliseconds simulates saccadic behavior. The target can be a virtual display, a direct‐view display or a projector image. Captured images can be used for quantifying the color breakup of a target display. The results along with an exploration of their application to breakup characterization will be presented.  相似文献   
28.
29.
Total hip replacement has become one of the most successful orthopaedic procedures. However, complications due to infections may give serious problems and have devastating consequences for the hip implant. The use of a temporary three-dimensional polymethylmethacrylate (PMMA) cement spacer may be an alternative to solve infections in hip implants, improving the lives of patients awaiting reimplantation. In order to evaluate their wear behaviour, five PMMA Spacer-G femoral heads were tested against five post-mortem pelves in a hip joint simulator with bovine calf serum as lubricant. The surface of the worn spacers was characterized by scanning electron microscopy (SEM) analysis; all the samples revealed a similar morphology, showing areas characterized by different degrees of wear. Particle debris was isolated from the lubricant and PMMA particles and bone fractions were quantified. The amount of debris was found to be higher than where no-temporary prostheses were used. However, this result is acceptable since wear debris is removed by lavage irrigation when the Spacer-G is explanted. On the basis of these data, it is considered that the use of the cement Spacer-G could be a promising approach to the treatment of complicated infections of the hip joint. Therefore, Spacer-G is worthy of further research.  相似文献   
30.
The marital relationship rarely exists in isolation and yet few studies have examined the multiple relationships experienced by most married people. This study used the Convoy Model of Social Relations to examine patterns of multiple relationships and well-being among men and women ages 22 to 79 years (N = 654). Cluster analyses identified profiles of relationship quality among people with spouse, family (children, mother, father), and a best friend (N = 451) and those married with family but no best friend (N = 202). Relationship profiles differed in quality and by gender, race, and age. Among people with best friends, having at least 2 high quality relations, not necessarily with a spouse, is associated with greater well-being. In contrast, among people without best friends, the spousal relation appears to be particularly important for well-being. Although family relationships (e.g., spouse) are important for well-being, interventions should consider the composition and quality of social networks to determine which relationships may need improvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号