全文获取类型
收费全文 | 3613篇 |
免费 | 203篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 38篇 |
综合类 | 1篇 |
化学工业 | 761篇 |
金属工艺 | 73篇 |
机械仪表 | 82篇 |
建筑科学 | 160篇 |
矿业工程 | 1篇 |
能源动力 | 113篇 |
轻工业 | 239篇 |
水利工程 | 33篇 |
石油天然气 | 13篇 |
无线电 | 365篇 |
一般工业技术 | 772篇 |
冶金工业 | 423篇 |
原子能技术 | 34篇 |
自动化技术 | 722篇 |
出版年
2023年 | 27篇 |
2022年 | 82篇 |
2021年 | 93篇 |
2020年 | 78篇 |
2019年 | 70篇 |
2018年 | 118篇 |
2017年 | 103篇 |
2016年 | 115篇 |
2015年 | 99篇 |
2014年 | 140篇 |
2013年 | 225篇 |
2012年 | 219篇 |
2011年 | 273篇 |
2010年 | 194篇 |
2009年 | 225篇 |
2008年 | 209篇 |
2007年 | 187篇 |
2006年 | 129篇 |
2005年 | 101篇 |
2004年 | 98篇 |
2003年 | 95篇 |
2002年 | 83篇 |
2001年 | 43篇 |
2000年 | 52篇 |
1999年 | 60篇 |
1998年 | 111篇 |
1997年 | 81篇 |
1996年 | 61篇 |
1995年 | 29篇 |
1994年 | 33篇 |
1993年 | 28篇 |
1992年 | 30篇 |
1991年 | 21篇 |
1990年 | 18篇 |
1989年 | 18篇 |
1988年 | 23篇 |
1987年 | 15篇 |
1986年 | 25篇 |
1985年 | 22篇 |
1984年 | 18篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 17篇 |
1979年 | 14篇 |
1977年 | 12篇 |
1976年 | 22篇 |
1974年 | 12篇 |
1973年 | 10篇 |
1972年 | 7篇 |
排序方式: 共有3830条查询结果,搜索用时 16 毫秒
101.
Product family modeling for mass customization 总被引:64,自引:0,他引:64
Jianxin Jiao Mitchell M. Tseng Vincent G. Duffy Fuhua Lin 《Computers & Industrial Engineering》1998,35(3-4):495-498
With growing reliance on modeling in product development, it is imperative to describe product families in a cohesive way. In particular, mass customization calls for a close integration of product life cycle from customer recognition to delivery and services. This paper proposes a triple-view scheme for modeling product families. Technical challenges are discussed by comparing product family modeling with modeling single products. Individual modeling formalisms for different views are discussed. An example of product family modeling in power supply design is presented to illustrate the feasibility and potential of the proposed approach. 相似文献
102.
103.
Soil water content and dry density are two important properties for compaction quality control. This paper presents a new method for determining soil water content and dry density using a single time domain reflectometry test, which is an improvement over that designated by ASTM D6780. This new method is based on simultaneous measurement of apparent dielectric constant and bulk electrical conductivity on the same soil sample. Calibration equations correlate these two parameters with soil gravimetric water content and dry density, which are simultaneously solved after adjusting field-measured conductivity to a standard conductivity. The method compensates for temperature effects. The test process takes about 3 min and all calculations are automated. Testing may be done in situ using a special probe that provides sufficient sampling volume or in a compaction mold adapted to form a probe. Laboratory and field tests results show this one-step method is a fast, accurate, and safe method for construction quality control. 相似文献
104.
Vincent E. Plumbley M. D. 《IEEE transactions on audio, speech, and language processing》2007,15(4):1273-1282
This paper deals with the decomposition of music signals into pitched sound objects made of harmonic sinusoidal partials for very low bit-rate coding purposes. After a brief review of existing methods, we recast this problem in the Bayesian framework. We propose a family of probabilistic signal models combining learned object priors and various perceptually motivated distortion measures. We design efficient algorithms to infer object parameters and build a coder based on the interpolation of frequency and amplitude parameters. Listening tests suggest that the loudness-based distortion measure outperforms other distortion measures and that our coder results in a better sound quality than baseline transform and parametric coders at 8 and 2 kbit/s. This work constitutes a new step towards a fully object-based coding system, which would represent audio signals as collections of meaningful note-like sound objects 相似文献
105.
Karine Loth Nicolas Parisot Franoise Paquet Hugo Terrasson Catherine Sivignon Isabelle Rahioui Mlanie Ribeiro Lopes Karen Gaget Gabrielle Duport Agns F. Delmas Vincent Aucagne Abdelaziz Heddi Federica Calevro Pedro da Silva 《International journal of molecular sciences》2022,23(20)
Aphids (Hemiptera: Aphidoidea) are among the most detrimental insects for agricultural plants, and their management is a great challenge in agronomical research. A new class of proteins, called Bacteriocyte-specific Cysteine-Rich (BCR) peptides, provides an alternative to chemical insecticides for pest control. BCRs were initially identified in the pea aphid Acyrthosiphon pisum. They are small disulfide bond-rich proteins expressed exclusively in aphid bacteriocytes, the insect cells that host intracellular symbiotic bacteria. Here, we show that one of the A. pisum BCRs, BCR4, displays prominent insecticidal activity against the pea aphid, impairing insect survival and nymphal growth, providing evidence for its potential use as a new biopesticide. Our comparative genomics and phylogenetic analyses indicate that BCRs are restricted to the aphid lineage. The 3D structure of BCR4 reveals that this peptide belongs to an as-yet-unknown structural class of peptides and defines a new superfamily of defensins. 相似文献
106.
Vincent W. Chen Dinesh S. Thakur Kirk J. Leister 《Journal of The Association for Laboratory Automation》1999,4(5):34
An architecture for building laboratory automation systems was developed using the component-based framework. The requirements to build a flexible and adaptable automation system were exemplified through the architectural design process. Existing tools and technologies facilitated the development of this scalable architecture. Several design patterns were used to model this architecture. The influence of these patterns on systems design and the impact of Unified Modeling Language on component and interface design was explored. Integration of the system components with the peripheral components to build an automated system is discussed with emphasis on run-time configuration and component reuse. 相似文献
107.
In this work, a variational Bayesian framework for efficient training of echo state networks (ESNs) with automatic regularization and delay&sum (D&S) readout adaptation is proposed. The algorithm uses a classical batch learning of ESNs. By treating the network echo states as fixed basis functions parameterized with delay parameters, we propose a variational Bayesian ESN training scheme. The variational approach allows for a seamless combination of sparse Bayesian learning ideas and a variational Bayesian space-alternating generalized expectation-maximization (VB-SAGE) algorithm for estimating parameters of superimposed signals. While the former method realizes automatic regularization of ESNs, which also determines which echo states and input signals are relevant for "explaining" the desired signal, the latter method provides a basis for joint estimation of D&S readout parameters. The proposed training algorithm can naturally be extended to ESNs with fixed filter neurons. It also generalizes the recently proposed expectation-maximization-based D&S readout adaptation method. The proposed algorithm was tested on synthetic data prediction tasks as well as on dynamic handwritten character recognition. 相似文献
108.
Chen G Palke D Zhongzang L Yeh H Vincent P Laramee RS Zhang E 《IEEE transactions on visualization and computer graphics》2011,17(12):1979-1988
Asymmetric tensor field visualization can provide important insight into fluid flows and solid deformations. Existing techniques for asymmetric tensor fields focus on the analysis, and simply use evenly-spaced hyperstreamlines on surfaces following eigenvectors and dual-eigenvectors in the tensor field. In this paper, we describe a hybrid visualization technique in which hyperstreamlines and elliptical glyphs are used in real and complex domains, respectively. This enables a more faithful representation of flow behaviors inside complex domains. In addition, we encode tensor magnitude, an important quantity in tensor field analysis, using the density of hyperstreamlines and sizes of glyphs. This allows colors to be used to encode other important tensor quantities. To facilitate quick visual exploration of the data from different viewpoints and at different resolutions, we employ an efficient image-space approach in which hyperstreamlines and glyphs are generated quickly in the image plane. The combination of these techniques leads to an efficient tensor field visualization system for domain scientists. We demonstrate the effectiveness of our visualization technique through applications to complex simulated engine fluid flow and earthquake deformation data. Feedback from domain expert scientists, who are also co-authors, is provided. 相似文献
109.
An improved approach to find membership functions and multiple minimum supports in fuzzy data mining
Chun-Hao Chen Tzung-Pei Hong Vincent S. Tseng 《Expert systems with applications》2009,36(6):10016-10024
Fuzzy mining approaches have recently been discussed for deriving fuzzy knowledge. Since items may have their own characteristics, different minimum supports and membership functions may be specified for different items. In the past, we proposed a genetic-fuzzy data-mining algorithm for extracting minimum supports and membership functions for items from quantitative transactions. In that paper, minimum supports and membership functions of all items are encoded in a chromosome such that it may be not easy to converge. In this paper, an enhanced approach is proposed, which processes the items in a divide-and-conquer strategy. The approach is called divide-and-conquer genetic-fuzzy mining algorithm for items with Multiple Minimum Supports (DGFMMS), and is designed for finding minimum supports, membership functions, and fuzzy association rules. Possible solutions are evaluated by their requirement satisfaction divided by their suitability of derived membership functions. The proposed GA framework maintains multiple populations, each for one item’s minimum support and membership functions. The final best minimum supports and membership functions in all the populations are then gathered together to be used for mining fuzzy association rules. Experimental results also show the effectiveness of the proposed approach. 相似文献
110.
Florian Turbant Jehan Waeytens Camille Campidelli Marianne Bombled Denis Martinez Axelle Grlard Birgit Habenstein Vincent Raussens Marisela Velez Frank Wien Vronique Arluison 《International journal of molecular sciences》2022,23(15)
Hfq is a pleiotropic regulator that mediates several aspects of bacterial RNA metabolism. The protein notably regulates translation efficiency and RNA decay in Gram-negative bacteria, usually via its interaction with small regulatory RNAs. Previously, we showed that the Hfq C-terminal region forms an amyloid-like structure and that these fibrils interact with membranes. The immediate consequence of this interaction is a disruption of the membrane, but the effect on Hfq structure was unknown. To investigate details of the mechanism of interaction, the present work uses different in vitro biophysical approaches. We show that the Hfq C-terminal region influences membrane integrity and, conversely, that the membrane specifically affects the amyloid assembly. The reported effect of this bacterial master regulator on membrane integrity is discussed in light of the possible consequence on small regulatory RNA-based regulation. 相似文献