全文获取类型
收费全文 | 620篇 |
免费 | 13篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 94篇 |
金属工艺 | 7篇 |
机械仪表 | 14篇 |
建筑科学 | 51篇 |
矿业工程 | 7篇 |
能源动力 | 17篇 |
轻工业 | 23篇 |
水利工程 | 8篇 |
石油天然气 | 6篇 |
无线电 | 49篇 |
一般工业技术 | 96篇 |
冶金工业 | 60篇 |
自动化技术 | 202篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 16篇 |
2017年 | 16篇 |
2016年 | 21篇 |
2015年 | 12篇 |
2014年 | 17篇 |
2013年 | 54篇 |
2012年 | 30篇 |
2011年 | 36篇 |
2010年 | 31篇 |
2009年 | 25篇 |
2008年 | 31篇 |
2007年 | 36篇 |
2006年 | 25篇 |
2005年 | 28篇 |
2004年 | 26篇 |
2003年 | 29篇 |
2002年 | 19篇 |
2001年 | 2篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 18篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1970年 | 3篇 |
排序方式: 共有637条查询结果,搜索用时 0 毫秒
41.
42.
This paper presents some of the theoretical predictions and experimental results for the steady-state characteristics of a gas-lubricated, pivoted-pad journal bearing of finite length. An analytical expression for the prediction of load-carrying capacity for these bearings is developed from numerical computer solutions. Sample calculations are presented to show how the theoretical data may be utilized in the design of an actual pivoted-pad bearing. Improvements over previous approximate theories are discussed. 相似文献
43.
Dipl.-Ing. Gunter Gschwandtner Robert Galler Viktoria Wörgetter Franz Riepler Sylke Hilberg 《BHM Berg- und Hüttenm?nnische Monatshefte》2013,158(2):53-59
The assessment of the stability of underground structures is an interdisciplinary task which consists of geology, hydrogeology, surveying and geotechnical engineering. This paper gives an example of how these disciplines, their methods and the acquisition of data work together to create a complex three-dimensional computer-model of underground structures. It demonstrates, that especially the complex layout of old and “grown” underground structures cannot be represented accurately in two-dimensional analyses or models and provide no realistic results for stability investigations. Related to the stability of underground structures, a non-negligible factor is the influence of water, whether surface, rain or groundwater. The occurring leaching process of gypsum leads to a weakening of the surrounding rock which causes a strength reduction. This softening of the material must be considered in long-term simulations. The presented comprehensive approach tries to provide a possibility to predict the time-dependent occurrence of vulnerabilities in the rock mass and thus gives the possibility to install support measures in an early stage. 相似文献
44.
Klaus Timmel Sven Eckert Gunter Gerbeth 《Metallurgical and Materials Transactions B》2011,42(1):68-80
This article describes laboratory experiments aimed at investigations of flow structures and related transport processes in
the continuous-casting mold under the influence of an external direct current (DC) magnetic field. The main value of cold
metal laboratory experiments consists in the capabilities to obtain quantitative flow measurements with a reasonable spatial
and temporal resolution. The experimental results presented here were obtained using a physical model operating with the room-temperature
alloy GaInSn. According to the concept of the electromagnetic brake, the impact of a DC magnetic field on the outlet flow
from the submerged entry nozzle (SEN) has been studied up to Hartmann numbers of approximately 400. The effect of the magnetic
field on the flow structure turned out to be complex. The flow measurements do not manifest a general braking effect, which
would be expected as an overall damping of the flow velocity and the related fluctuations all over the mold volume. Variations
of the wall conductivity showed a striking impact on the resulting flow structures. The experiments provide a substantial
database for the validation of respective numerical simulations. 相似文献
45.
46.
Victor Gabriel Marian Dumitru Gabriel Gunter Knoll Salvatore Filippone 《Tribology Letters》2011,44(3):335-343
In this article, a laser partially textured thrust bearing is theoretically and experimentally analyzed. An adiabatic model
is developed in order to theoretically investigate the performances of the bearing. The bearing sample is partially textured
both in radial and circumferential direction using the laser texturing process. The performance of the bearing (fluid film
thickness and friction torque) is evaluated on a specially adapted test rig and the experimental results are compared with
the theoretical model. A good agreement is found between the theoretical model and the experimental data. Also a comparison
between a laser textured bearing and a bearing textured using the photolithographic method is presented. 相似文献
47.
48.
Kate Sanders Sally Fincher Dennis Bouvier Gary Lewandowski Briana Morrison Laurie Murphy Marian Petre Brad Richards Josh Tenenberg Lynda Thomas Richard Anderson Ruth Anderson Sue Fitzgerald Alicia Gutschow Susan Haller Raymond Lister Renée McCauley John McTaggart Christine Prasad Terry Scott Dermot Shinners-Kennedy Suzanne Westbrook Carol Zander 《Expert Systems》2005,22(3):121-128
Abstract: This paper presents a case study of the use of a repeated single‐criterion card sort with an unusually large, diverse participant group. The study, whose goal was to elicit novice programmers' knowledge of programming concepts, involved over 20 researchers from four continents and 276 participants drawn from 20 different institutions. In this paper we present the design of the study and the unexpected result that there were few discernible systematic differences in the population. The study was one of the activities of the National Science Foundation funded Bootstrapping Research in Computer Science Education project (2003). 相似文献
49.
Integrating heterogeneous database schemata is a major task in federated database design where preexisting and heterogeneous database systems need to be integrated virtually by providing a homogenization database interface. Most proposed schema integration methods suffer from very complex result schemata and insufficient handling of extensional relations, i.e. in the way how redundant data of the input systems are dealt with. Redundancy among the input systems may thus remain undetected and, hence, remains uncontrolled.Our GIM (Generic Integration Model) method is based on the elegant and mathematically founded theory of formal concept analysis (FCA). The main idea is to integrate schemata into one formal context which is a binary relation between a set of attributes and a set of base extensions (set of potential objects). From that context we apply an FCA-algorithm to semi-automatically derive a concept lattice which we interpret as an inheritance hierarchy of classes for a homogenized schema. Thus, the integration task following our method can be supported by tools. 相似文献
50.