全文获取类型
收费全文 | 2769篇 |
免费 | 134篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 32篇 |
化学工业 | 517篇 |
金属工艺 | 39篇 |
机械仪表 | 66篇 |
建筑科学 | 159篇 |
矿业工程 | 11篇 |
能源动力 | 150篇 |
轻工业 | 236篇 |
水利工程 | 24篇 |
石油天然气 | 2篇 |
无线电 | 246篇 |
一般工业技术 | 573篇 |
冶金工业 | 183篇 |
原子能技术 | 15篇 |
自动化技术 | 653篇 |
出版年
2023年 | 20篇 |
2022年 | 39篇 |
2021年 | 65篇 |
2020年 | 51篇 |
2019年 | 61篇 |
2018年 | 63篇 |
2017年 | 76篇 |
2016年 | 97篇 |
2015年 | 72篇 |
2014年 | 110篇 |
2013年 | 196篇 |
2012年 | 197篇 |
2011年 | 249篇 |
2010年 | 160篇 |
2009年 | 154篇 |
2008年 | 174篇 |
2007年 | 151篇 |
2006年 | 123篇 |
2005年 | 109篇 |
2004年 | 94篇 |
2003年 | 79篇 |
2002年 | 73篇 |
2001年 | 54篇 |
2000年 | 37篇 |
1999年 | 31篇 |
1998年 | 34篇 |
1997年 | 33篇 |
1996年 | 21篇 |
1995年 | 29篇 |
1994年 | 19篇 |
1993年 | 7篇 |
1992年 | 15篇 |
1991年 | 13篇 |
1990年 | 14篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1978年 | 4篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1973年 | 6篇 |
排序方式: 共有2906条查询结果,搜索用时 62 毫秒
101.
102.
Andreas Björnsson Marie Jonsson Daniel Eklund Jan Erik Lindbäck Mats Björkman 《Production Engineering》2017,11(4-5):445-453
Automated manufacturing of composite parts based on prepreg material is receiving increased interest with the rising use of composite materials for high-performance applications. The two main automation alternatives for prepreg layup, automated tape layup and fiber placement, are not cost-effective for all types of products, and manual labor is common for the manufacturing of complex parts in low manufacturing volumes. Alternatives to the two dominant automation solutions have been pursued, but so far these have had a limited impact in industrial applications. This paper presents four different solutions for automated layup of prepreg plies to flat laminates that can be formed in a subsequent forming process, which decrease the system complexity. The solutions target products where the layup of flat laminates today is done manually due to technical limitations or cost considerations. The layup solutions must manage challenges caused by material properties such as low material rigidity and tack, and be able to handle a high number of ply shapes. All four solutions are designed for prepreg that is covered with a stiff backing paper. The aim of the paper is to analyze and compare the four solutions. It can be concluded that the most versatile solution is a dual-arm robot equipped with simple end effectors. The dual-arm solution presents a possibility to control the pick-up and lay-down motions that make peeling motions possible, which is advantageous when picking material that has tacked to the pickup surface. 相似文献
103.
Jonathan Byrne Erik Hemberg Michael O’Neill Anthony Brabazon 《Genetic Programming and Evolvable Machines》2013,14(3):287-314
A designer should be able to express their intentions with a design tool. This work describes a methodology that enables the architect to directly interact with the encoding of designs they find aesthetically pleasing. Broadening interaction beyond simple evaluation increases the amount of feedback and bias a user can apply to the search. Increased feedback will have the effect of directing the algorithm to more fruitful areas of the search space. We conduct trials on two interfaces for making localised changes to a design in order to evaluate if the user is capable of directing search. In addition, an examination of the locality of changes made by the users provides an insight into how they explore the search space. The results show that a suitably designed interface is capable of directing search and that the participants used different magnitudes of change during directed search. 相似文献
104.
105.
Zachary Freudenburg Khaterah Kohneshin Erik Aarnoutse Mariska Vansteensel Mariana Branco Sacha Leinders Max van den Boom Elmar G. M. Pels Nick Ramsey 《控制理论与应用(英文版)》2021,19(4):444-454
While brain computer interfaces (BCIs) offer the potential of allowing those suffering from loss of muscle control to once
again fully engage with their environment by bypassing the affected motor system and decoding user intentions directly from
brain activity, they are prone to errors. One possible avenue for BCI performance improvement is to detect when the BCI user
perceives the BCI to have made an unintended action and thus take corrective actions. Error-related potentials (ErrPs) are
neural correlates of error awareness and as such can provide an indication of when a BCI system is not performing according
to the user’s intentions. Here, we investigate the brain signals of an implanted BCI user suffering from locked-in syndrome
(LIS) due to late-stage ALS that prevents her from being able to speak or move but not from using her BCI at home on a
daily basis to communicate, for the presence of error-related signals. We first establish the presence of an ErrP originating
from the dorsolateral pre-frontal cortex (dLPFC) in response to errors made during a discrete feedback task that mimics the
click-based spelling software she uses to communicate. Then, we show that this ErrP can also be elicited by cursor movement
errors in a continuous BCI cursor control task. This work represents a first step toward detecting ErrPs during the daily
home use of a communications BCI. 相似文献
106.
Aluminum alloys are heat treated to provide optimal material properties for use in a variety of applications. However, when exposed to abnormally high temperatures, an evaluation must be performed to determine if the aluminum component has been compromised. Nondestructive evaluation of aluminum alloys, by means of electrical conductivity and hardness tests, can assist in determining the condition of the part. These techniques require experience and engineering judgment to properly interpret the data produced in order to determine whether a part needs to be replaced. This article will elaborate on issues with these nondestructive techniques to help diagnose the condition of aluminum alloys exposed to high temperatures. 相似文献
107.
Erik P. van Geest Khosrow Shakouri Wangyang Fu Vincent Robert Viorica Tudor Sylvestre Bonnet Grégory F. Schneider 《Advanced materials (Deerfield Beach, Fla.)》2020,32(10):1903575
Direct electrical probing of molecular materials is often impaired by their insulating nature. Here, graphene is interfaced with single crystals of a molecular spin crossover complex, [Fe(bapbpy)(NCS)2], to electrically detect phase transitions in the molecular crystal through the variation of graphene resistance. Contactless sensing is achieved by separating the crystal from graphene with an insulating polymer spacer. Next to mechanical effects, which influence the conductivity of the graphene sheet but can be minimized by using a thicker spacer, a Dirac point shift in graphene is observed experimentally upon spin crossover. As confirmed by computational modeling, this Dirac point shift is due to the phase-dependent electrostatic potential generated by the crystal inside the graphene sheet. This effect, named as chemo-electric gating, suggests that molecular materials may serve as substrates for designing graphene-based electronic devices. Chemo-electric gating, thus, opens up new possibilities to electrically probe chemical and physical processes in molecular materials in a contactless fashion, from a large distance, which can enhance their use in technological applications, for example, as sensors. 相似文献
108.
Hinkel Georg Goldschmidt Thomas Burger Erik Reussner Ralf 《Software and Systems Modeling》2019,18(1):129-155
Software and Systems Modeling - Model-driven engineering (MDE) has proved to be a useful approach to cope with today’s ever-growing complexity in the development of software systems;... 相似文献
109.
110.
Davy Van Deursen Wim Van Lancker Erik Mannens Rik Van de Walle 《Multimedia Tools and Applications》2014,70(2):827-846
W3C’s Video in the Web activity aims at a better integration of media within the Web. In this paper, we show how two specifications currently under development within this activity, i.e., Media Fragment URIs and Media Annotations, can be combined within media-enabled HTML5 Web applications. In particular, we introduce a number of extensions for the Media Annotations ontology in order to close the gap with Media Fragment URIs. Additionally, we show how rich media fragment annotations can be converted into a WebVTT file. The latter can be used by HTML5-enabled players to show the annotations in a synchronized way. Further, a fully integrated Web application has been developed that shows how both specifications can work together within an HTML5 environment. This application relies on NinSuna, our media delivery platform targeted at multichannel publication that provides server-side support for both Media Fragment URIs and Media Annotations. 相似文献