全文获取类型
收费全文 | 953篇 |
免费 | 53篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
综合类 | 3篇 |
化学工业 | 213篇 |
金属工艺 | 23篇 |
机械仪表 | 12篇 |
建筑科学 | 49篇 |
能源动力 | 24篇 |
轻工业 | 77篇 |
水利工程 | 8篇 |
石油天然气 | 1篇 |
无线电 | 68篇 |
一般工业技术 | 180篇 |
冶金工业 | 122篇 |
原子能技术 | 6篇 |
自动化技术 | 209篇 |
出版年
2023年 | 16篇 |
2022年 | 20篇 |
2021年 | 31篇 |
2020年 | 20篇 |
2019年 | 23篇 |
2018年 | 30篇 |
2017年 | 20篇 |
2016年 | 45篇 |
2015年 | 30篇 |
2014年 | 41篇 |
2013年 | 55篇 |
2012年 | 51篇 |
2011年 | 64篇 |
2010年 | 47篇 |
2009年 | 49篇 |
2008年 | 39篇 |
2007年 | 40篇 |
2006年 | 40篇 |
2005年 | 20篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 20篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 31篇 |
1997年 | 22篇 |
1996年 | 22篇 |
1995年 | 17篇 |
1994年 | 17篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 3篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1975年 | 7篇 |
1973年 | 3篇 |
1970年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有1007条查询结果,搜索用时 15 毫秒
1.
2.
3.
F F?ndrich AM Waaga J Schr?der E Schweizer A Schmid S Jacob HH Wacker P Schroeder 《Canadian Metallurgical Quarterly》1995,27(2):1553-1554
4.
J. G. Zheng Xiaoqing Pan M. Schweizer U. Weimar W. Göpel M. Rühle 《Journal of Materials Science》1996,31(9):2317-2324
Atomic structures of crystallographic shear planes (CSPs) in nanocrystalline thin films of semiconductor SnO2 were investigated by high-resolution electron microscopy. The films were prepared by electron beam evaporation in high vacuum (10–6 torr) and followed by annealing in synthetic air at 700 °C for 1–2 H. CSPs with the displacement vector of [1/2 0 1/2] were observed in the planes parallel to (¯101), (110) and (¯3¯21). Most of the CPSs were found to terminate or interact with each other within SnO2 crystallites. Partial dislocations exist at terminal places of CSPs or along intersecting lines of CSPs. CSP steps were also observed. Structural models of these defects have been proposed. Based on analysis of experimental data, it has been suggested that the Sn/O ratio at CSPs which are not parallel to their displacement vector, at cores of partial dislocations and at CSP steps, is higher than that of the perfect structure, that is, these defects are able to provide extra free electrons with the films. 相似文献
5.
Nils Hallbäck Fred Nilsson 《Fatigue & Fracture of Engineering Materials & Structures》1992,15(2):173-185
The fracture assessment of structures subjected to secondary loading systems was studied by FEM-analysis of a few illustrative two-dimensional examples. The first example is an edge-cracked plate with a thermal gradient. The FEM-calculations revealed that a purely elastic analysis yielded J-values that are in most cases considerably more conservative than the ones calculated from an elastic-plastic analysis. The results were further compared with different engineering type non-linear estimates. As a second example a crack emanating from a semi-circular notch in a rectangular plate was chosen. The plate was subjected to uniaxial tension along its boundaries. It turned out that for the cases considered the J-values were fairly close to those elastically predicted. 相似文献
6.
W Astfalk FM H?cker HJ Kirschner G Stuhldreier P Schweizer 《Canadian Metallurgical Quarterly》1997,122(10):898-900
Since 1990, we have been conducting ambulatory pediatric surgery in an unit established solely for this purpose, supported by a team of kindergarten teachers, pediatric nurses, anesthesiologists and pediatric surgeons. This prospective investigation includes all ambulatory pediatric operations performed in our department from 1990 to 1995. In this time 3665 infants and children between the ages of 6 weeks and 18 years underwent an ambulatory operation. The ratio male to female was 4.1 to 1. The series consists of 1400 inguinal hernias, 722 inguinal testes, 191 hydroceles/funiculoceles, 75 umbilical hernias, 667 phimoses, 70 meatotomies, 59 hemangiomas, 217 endoscopies and 264 other surgical procedures. Postoperative complications defined as secondary hemorrhage, fever, obvious vomiting, urine retention and laryngospasm upon terminating anesthesia accompanied by subsequent vomiting occurred in 59 (1.6%) of all infants and children. Wound infections were seen in 0.48% (17/3517) of all patients. The recurrence rate for inguinal hernias were 0.79% and 1.12% for inguinal testes. Our experience enables us to summarize that a variety of pediatric operations can be performed today as ambulatory procedures. Nevertheless one must be prepared for the occurrence of complications and always have capacities free for inpatient care where adequate observation and treatment are available. Further improvement is necessary in quality management. In the last 20 years only a few data have been published about recurrence rates after pediatric ambulatory operations for inguinal hernias and inguinal testes. Therefore we started a prospective long- term study. 相似文献
7.
Schweizer Informatik Gesellschaft 《Informatik-Spektrum》2008,31(3):285-287
Ohne Zusammenfassung 相似文献
8.
Robert L. Stevenson Susan M. Schweizer 《Journal of Mathematical Imaging and Vision》1992,2(2-3):137-154
This paper introduces a new nonlinear filtering structure for filtering image data that have been corrupted by both impulsive and nonimpulsive additive noise. Like other nonlinear filters, the proposed filtering structure uses order-statistic operations to remove the effects of the impulsive noise. Unlike other filters, however, nonimpulsive noise is smoothed by using a maximum a posteriori estimation criterion. The prior model for the image is a novel Markov random-field model that models image edges so that they are accurately estimated while additive Gaussian noise is smoothed. The Markov random-field-based prior is chosen such that the filter has desirable analytical and computational properties. The estimate of the signal value is obtained at the unique minimum of the a posteriori log likelihood function. This function is convex so that the output of the filter can be easily computed by using either digital or analog computational methods. The effects of the various parameters of the model will be discussed, and the choice of the predetection order statistic filter will also be examined. Example outputs under various noise conditions will be given. 相似文献
9.
Schweizer Informatik Gesellschaft 《Informatik-Spektrum》2007,30(5):401-403
Ohne Zusammenfassung 相似文献
10.
Schweizer Informatik Gesellschaft 《Informatik-Spektrum》2007,30(3):234-235
Ohne Zusammenfassung 相似文献