全文获取类型
收费全文 | 8898篇 |
免费 | 596篇 |
国内免费 | 20篇 |
学科分类
工业技术 | 9514篇 |
出版年
2023年 | 57篇 |
2022年 | 109篇 |
2021年 | 172篇 |
2020年 | 146篇 |
2019年 | 198篇 |
2018年 | 225篇 |
2017年 | 224篇 |
2016年 | 286篇 |
2015年 | 252篇 |
2014年 | 348篇 |
2013年 | 582篇 |
2012年 | 496篇 |
2011年 | 581篇 |
2010年 | 507篇 |
2009年 | 469篇 |
2008年 | 497篇 |
2007年 | 409篇 |
2006年 | 385篇 |
2005年 | 325篇 |
2004年 | 297篇 |
2003年 | 267篇 |
2002年 | 246篇 |
2001年 | 152篇 |
2000年 | 176篇 |
1999年 | 128篇 |
1998年 | 152篇 |
1997年 | 125篇 |
1996年 | 136篇 |
1995年 | 105篇 |
1994年 | 121篇 |
1993年 | 94篇 |
1992年 | 79篇 |
1991年 | 62篇 |
1990年 | 75篇 |
1989年 | 76篇 |
1988年 | 48篇 |
1987年 | 61篇 |
1986年 | 53篇 |
1985年 | 65篇 |
1984年 | 68篇 |
1983年 | 58篇 |
1982年 | 61篇 |
1981年 | 53篇 |
1980年 | 47篇 |
1979年 | 62篇 |
1977年 | 57篇 |
1976年 | 40篇 |
1975年 | 26篇 |
1974年 | 30篇 |
1973年 | 29篇 |
排序方式: 共有9514条查询结果,搜索用时 15 毫秒
991.
992.
Marc Tassoul 《Creativity & Innovation Management》1998,7(1):32-45
During his work as a creativity practitioner and researcher, the author has developed a Future Perfect approach to achieve a collaborative sense and vision about issues of change. This article reports the experience of both participants and facilitator in using this process, in a project undertaken to develop new approaches to clean textiles in the context of sustainable development. The process is described in part on the basis of McWhinney’s ‘Six Systems Model’ and Catford and Ray’s ‘Path of the Everyday Hero’. The experience is then developed into helpful hints for creativity practitioners. 相似文献
993.
994.
995.
The main objective of this paper is to analyse residential demand by traffic destination, using a translogarithmic indirect utility function. We focus on five traffic directions, in order to construct a model adapted to evaluate the characteristics of telecommunications demand in a competitive market. The resulting price elasticities express high reactivity to own price changes for the main traffic directions, as well as little interactions between the different types of traffic. Moreover, the high values of income elasticities confirm the importance of income effects when analysing residential telecommunications demand. This model shows useful for welfare analysis. The computation of customers' income equivalent variation shows, on average, a higher willingness to pay for some traffic directions than the bill actually paid. Finally, we show that the optimal prices for the operator, in a cost minimisation point of view, are higher than the observed prices for local and national traffic directions. This emphasises the existence of important cross-subsidies among the different segments of customers. 相似文献
996.
Jean Augereau Yves Ousten Bruno Levrier Laurent Bechou 《Microelectronics Reliability》2006,46(9-11):1922-1925
Assembly technologies follow the reduction in size of circuit board components and correlatively the number of active layers increases significantly. Therefore, during a conventional acoustic analysis, the obtained image becomes more and more complicated to analyze. In a previous paper, we focused our research on a method for a suitable visualization of the timescale of an acoustic signal (CWT). In this paper we present the use of the non-destructive control for the study of a 3D package submitted to accelerated ageing tests using harsh conditions. 相似文献
997.
Marc Niethammer William D Kalies Konstantin Mischaikow Allen Tannenbaum 《IEEE transactions on image processing》2006,15(8):2462-2469
Simple point detection is an important task for several problems in discrete geometry, such as topology preserving thinning in image processing to compute discrete skeletons. In this paper, the approach to simple point detection is based on techniques from cubical homology, a framework ideally suited for problems in image processing. A (d-dimensional) unitary cube (for a d-dimensional digital image) is associated with every discrete picture element, instead of a point in epsilon(d) (the d-dimensional Euclidean space) as has been done previously. A simple point in this setting then refers to the removal of a unitary cube without changing the topology of the cubical complex induced by the digital image. The main result is a characterization of a simple point p (i.e., simple unitary cube) in terms of the homology groups of the (3d - 1) neighborhood of p for arbitrary, finite dimensions 相似文献
998.
Enns Carolyn Zerbe; Campbell Jean; Courtois Christine A. 《Canadian Metallurgical Quarterly》1997,34(4):459
This article proposes principles for working effectively with survivors of domestic violence. Recommendations are based on a review of the available literature and organized within the following sections: therapist competence, therapeutic framework and relationship, assessment and diagnosis, the structure of the treatment process and relationship, interventions for dealing with posttraumatic reactions, and group interventions. The relevance of the delayed memory debate for domestic violence survivors is also discussed. The complexity of battering dynamics and the need for sensitive, competent treatment of victims are emphasized. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
999.
This paper presents a new fully differential CMOS class AB transmitter for 10 Gb/s serial links. The transmitter consists
of a fully differential multiplexer, a rail-to-rail configured pre-amplification stage, and a push-pull output stage. The
multiplexer achieves a high multiplexing speed by using modified pseudo-NMOS logic where pull-up networks are replaced with
self-biased active inductors. The rail-to-rail configured pre-amplification stage with active inductors amplifies the signals
from the multiplexer. The fully differential output current is generated by a class AB output stage operated in a push-pull
mode. High data rates of the transmitter are obtained by ensuring that the transistors in both the pre-amplification and output
stages are always in saturation and the voltage swing of all critical nodes is small. The fully differential configuration
of the transmitter effectively suppresses common-mode disturbances, particularly those coupled from the power and ground rails,
the electro-magnetic interference exerted from channels to neighboring devices is also minimized. The transmitter minimizes
switching noise by drawing a constant current from the supply voltage.
The transmitter has been implemented in TSMC 0.18 μm 1.8 V 6-metal CMOS technology and analyzed using Spectre from Cadence
Design Systems with BSIM3.3 device models. Simulation results demonstrate that the transmitter provides a 5 mA peak-to-peak
differential output current with 100 ps eye-width and >5 mA eye-height at 10 Gb/s. The transmitter consumes 18 mW with a total
transistor area of 100 μm2 approximately.
Jean Jiang received the B.Eng. degree in Electrical Engineering from Wuhan University of Technology, Wuhan, China in 1995, and the M.A.Sc.
degree in Electrical and Computer Engineering from Ryerson University, Toronto, Ontario, Canada in 2004. From 1999 to 2001,
she worked for Ericsson Global IT Services where she was a technical staff to maintain computer networks. From 2002 to 2004,
she was a research assistant and a M.A.Sc. student with the Microsystem Research Laboratory in the Department of Electrical
and Computer Engineering at Ryerson University. She is now with Intel Corp., CA. as an IC design engineer. Her research interests
are in analog CMOS circuit design for high-speed data communications. Jean Jiang was awarded the Ontario Graduate Scholarship
in 2003–2005 for academic excellence.
Fei Yuan received the B.Eng. degree in electrical engineering from Shandong University, Jinan, China in 1985, the M.A.Sc. degree in
chemical engineering and Ph.D. degree in electrical engineering from University of Waterloo, Waterloo, Ontario, Canada in
1995 and 1999, respectively. During 1985–1989, he was a Lecturer in the Department of Electrical Engineering, Changzhou Institute
of Technology, Jiangsu, China. In 1989 he was a Visiting Professor at Humber College of Applied Arts and Technology, Toronto,
Ontario, Canada, and Lambton College of Applied Arts and Technology, Sarnia, Ontario, Canada. He was with Paton Controls Limited,
Sarnia, Ontario, Canada as a Controls Engineer during 1989–1994. Since 1999 he has been with the Department of Electrical
and Computer Engineering, Ryerson University, Toronto, Ontario, Canada, where he is currently an Associate Professor and the
Associate Chair for Undergraduate Studies and Faculty Affairs. He is the co-author of the book Computer Methods for Analysis of Mixed-Mode Switching Circuits (Springer-Verlag, 2004, with Ajoy Opal).
Dr. Yuan received the Ryerson Research Chair award from Ryerson University in Jan. 2005, the Research Excellence Award from
the Faculty of Engineering and Applied Science of Ryerson University in 2004, the post-graduate scholarship from Natural Science
and Engineering Research Council of Canada during 1997–1998, and the Teaching Excellence Award from Changzhou Institute of
Technology in 1988. Dr. Yuan is a senior member of IEEE and a registered professional engineer in the province of Ontario,
Canada. 相似文献
1000.
Comment on the article, "Regulation of Drug Taking by Sensitization and Habituation," by McSweeney, et al (see record 2005-10634-001). McSweeney, Murphy, and Kowal offer the intriguing suggestion that the basic behavioral processes of habituation and sensitization play an important role in drug taking, specifically, repeated drug taking. The suggestion is noteworthy because, if correct, it, as the authors point out, could lead to new approaches to prevention and treatment, approaches that involve the use of environmental variables that are relatively accessible. I think their exposition raises several issues. A number of these questions are related to the phenomenon of drug tolerance, an outcome that can be understood as either an instance of or deriving from the process of habituation. The presentation also contains passages in which the logic is not fully clear. Another issue I have with the article is the overall logic approach on the basis of features of drug addiction. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献