全文获取类型
收费全文 | 1491篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
综合类 | 1篇 |
化学工业 | 214篇 |
金属工艺 | 17篇 |
机械仪表 | 14篇 |
建筑科学 | 55篇 |
矿业工程 | 2篇 |
能源动力 | 19篇 |
轻工业 | 161篇 |
水利工程 | 7篇 |
石油天然气 | 4篇 |
无线电 | 75篇 |
一般工业技术 | 154篇 |
冶金工业 | 643篇 |
原子能技术 | 19篇 |
自动化技术 | 128篇 |
出版年
2022年 | 13篇 |
2020年 | 13篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 19篇 |
2016年 | 18篇 |
2015年 | 18篇 |
2014年 | 21篇 |
2013年 | 73篇 |
2012年 | 38篇 |
2011年 | 72篇 |
2010年 | 47篇 |
2009年 | 45篇 |
2008年 | 62篇 |
2007年 | 59篇 |
2006年 | 61篇 |
2005年 | 53篇 |
2004年 | 26篇 |
2003年 | 39篇 |
2002年 | 39篇 |
2001年 | 25篇 |
2000年 | 26篇 |
1999年 | 21篇 |
1998年 | 85篇 |
1997年 | 49篇 |
1996年 | 54篇 |
1995年 | 35篇 |
1994年 | 38篇 |
1993年 | 34篇 |
1992年 | 19篇 |
1991年 | 19篇 |
1990年 | 29篇 |
1989年 | 30篇 |
1988年 | 22篇 |
1987年 | 28篇 |
1986年 | 24篇 |
1985年 | 32篇 |
1984年 | 21篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 9篇 |
1979年 | 19篇 |
1978年 | 20篇 |
1977年 | 20篇 |
1976年 | 16篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1973年 | 9篇 |
1972年 | 8篇 |
排序方式: 共有1518条查询结果,搜索用时 15 毫秒
91.
92.
Tomás Sánchez López Damith C. Ranasinghe Mark Harrison Duncan McFarlane 《Personal and Ubiquitous Computing》2012,16(3):291-308
The Internet of Things (IoT) concept is being widely presented as the next revolution toward massively distributed information,
where any real-world object can automatically participate in the Internet and thus be globally discovered and queried. Despite
the consensus on the great potential of the concept and the significant progress in a number of enabling technologies, there
is a general lack of an integrated vision on how to realize it. This paper examines the technologies that will be fundamental
for realizing the IoT and proposes an architecture that integrates them into a single platform. The architecture introduces
the use of the Smart Object framework to encapsulate radio-frequency identification (RFID), sensor technologies, embedded
object logic, object ad-hoc networking, and Internet-based information infrastructure. We evaluate the architecture against
a number of energy-based performance measures, and also show that it outperforms existing industry standards in metrics such
as network throughput, delivery ratio, or routing distance. Finally, we demonstrate the feasibility and flexibility of the
architecture by detailing an implementation using Wireless Sensor Networks and Web Services, and describe a prototype for
the real-time monitoring of goods flowing through a supply chain. 相似文献
93.
Anshu Dubey Klaus Weide Dongwook Lee John Bachan Christopher Daley Samuel Olofin Noel Taylor Paul M. Rich Lynn B. Reid 《Software》2015,45(2):233-244
When developing a complex, multi‐authored code, daily testing on multiple platforms and under a variety of conditions is essential. It is therefore necessary to have a regression test suite that is easily administered and configured, as well as a way to easily view and interpret the test suite results. We describe the methodology for verification of FLASH, a highly capable multiphysics scientific application code with a wide user base. The methodology uses a combination of unit and regression tests and an in‐house testing software that is optimized for operation under limited resources. Although our practical implementations do not always comply with theoretical regression‐testing research, our methodology provides a comprehensive verification of a large scientific code under resource constraints.Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
94.
Building brains for bodies 总被引:8,自引:2,他引:8
We describe a project to capitalize on newly available levels of computational resources in order to understand human cognition. We are building an integrated physical system including vision, sound input and output, and dextrous manipulation, all controlled by a continuously operating large scale parallel MIMD computer. The resulting system will learn to think by building on its bodily experiences to accomplish progressively more abstract tasks. Past experience suggests that in attempting to build such an integrated system we will have to fundamentally change the way artificial intelligence, cognitive science, linguistics, and philosophy think about the organization of intelligence. We expect to be able to better reconcile the theories that will be developed with current work in neuroscience. 相似文献
95.
Tomás Sánchez López Damith Chinthana Ranasinghe Bela Patkai Duncan McFarlane 《Information Systems Frontiers》2011,13(2):281-300
Deployment of embedded technologies is increasingly being examined in industrial supply chains as a means for improving efficiency
through greater control over purchase orders, inventory and product related information. Central to this development has been
the advent of technologies such as bar codes, Radio Frequency Identification (RFID) systems, and wireless sensors which when
attached to a product, form part of the product’s embedded systems infrastructure. The increasing integration of these technologies
dramatically contributes to the evolving notion of a “smart product”, a product which is capable of incorporating itself into
both physical and information environments. The future of this revolution in objects equipped with smart embedded technologies
is one in which objects can not only identify themselves, but can also sense and store their condition, communicate with other
objects and distributed infrastructures, and take decisions related to managing their life cycle. The object can essentially
“plug” itself into a compatible systems infrastructure owned by different partners in a supply chain. However, as in any development
process that will involve more than one end user, the establishment of a common foundation and understanding is essential
for interoperability, efficient communication among involved parties and for developing novel applications. In this paper,
we contribute to creating that common ground by providing a characterization to aid the specification and construction of
“smart objects” and their underlying technologies. Furthermore, our work provides an extensive set of examples and potential
applications of different categories of smart objects. 相似文献
96.
K. Yamaura Q. Huang R.W. Erwin J.W. Lynn R.J. Cava 《Journal of Low Temperature Physics》1999,117(3-4):849-853
The crystal structure of Sr
2
Y
0.8
Ca
0.2
Co
2
O
6
is orthorhombic below 270 K (Immm, a = 3.84029(7) Å, b = 3.80691(6) Å and c = 19.4980(3) Å at 20 K), transformed from tetragonal (I4/mmm, a = 3.82765(6) Å and c = 19.5795(3) Å) at 295 K. The crystal structure distortion is accompanied by an anomalous temperature dependence of the degree of buckling of the CoO
2
plane and is correlated with the development of anisotropic antiferromagnetic ordering of magnetic moments (2.93(2)
B
per Co at 20 K). A magnetically glassy state below about 35 K and variable range hopping conduction below about 64 K for
were found by magnetic susceptibility and electrical resistivity measurements. 相似文献
97.
B. Lynn Bodner 《Nexus Network Journal》2012,14(2):307-332
In this paper we will explore two nine- and twelvepointed Islamic star polygon patterns consisting of ??nearly regular?? nine-pointed, regular twelve-pointed and irregularly-shaped pentagonal star polygons. The two designs are similar in that they may both be classified mathematically as being p6m patterns with the major star polygons placed in identical locations within each layout; however, the structure of the major stars is quite different. Both of the patterns considered here are of Persian origin. The first design may be found as a repeat unit sketch of the Tashkent Scrolls, and exists as a Timurid-style stone inlay and mosaic tiling in India. The second pattern may be found as Plate 120 of Bourgoin??s Arabic Geometrical Pattern and Design and exists as a stucco/plasterwork ceiling in the Mausoleum of Sultan Oljaytu in Sultaniyeh, Iran, as well as numerous other locations across the Islamic world. Both patterns may be recreated via plausible Euclidean ??point-joining?? constructions (that is, using only the methods available to medieval artisans) in an attempt to ascertain how the original designers of these patterns may have determined the proportion and placement of the stars. 相似文献
98.
Anbumani?Subramanian Lakshmi?R.?Iyer A.?Lynn?Abbott Amy?E.?BellEmail author 《Machine Vision and Applications》2003,15(1):46-53
The use of a novel motorized lens to perform segmentation of image sequences is presented in this paper. The lens has the effect of introducing small, repeating movements of the camera center so that objects appear to translate in the image by an amount that depends on the distance from the plane of focus. For a stationary scene, optical flow magnitudes are therefore directly related to three-dimensional object distance from the observer. We describe a segmentation procedure that exploits these controlled observer movements and present experimental results that demonstrate the successful extraction of objects at different depths. Potential applications of our approach include image compositing, teleconferencing, and range estimation.Received: 4 July 2002, Accepted: 16 December 2002, Published online: 23 July 2003
Correspondence to: Amy E. Bell 相似文献
99.
Lynn J. Brady 《Journal of Materials Science》1980,15(2):477-482
It is shown that a specimen's microstructure affects the form of its magnetization curves but notM
s, the saturation magnetic moment per cm3 norH
s, the applied field strength required for saturation. A procedure is then given for the precise determination ofM
s andH
s using data derived from the hysteresis loops of polycrystalline isotropic specimens. The procedure is simple to use and avoids
the laborious extrapolation requirements of the “law of approach”. Finally, the magnetization processes involved in forming
the hysteresis loops betweenH
s and —H
s are described. 相似文献
100.
Swain Ralph W. Lynn Walter R. Hodgson Thomas A. Becker Niels G. Johnson Kenneth G. 《IEEE transactions on bio-medical engineering》1972,(2):120-125
Epidemiological simulation models to be used primarily to augment the teaching of epidemiology to medical students and other individuals concerned with public health and control of epidemics are presented. Interactive simulations are used to expose students to ``realistic' epidemic situations and permit them to experiment with various control strategies. Criteria by which simulations for such teaching purposes may be evaluated are proposed and operating simulations, MEASLES and INFLU, are described in detail. Information is provided regarding user experience with the above simulations. 相似文献