全文获取类型
收费全文 | 5441篇 |
免费 | 735篇 |
国内免费 | 683篇 |
专业分类
电工技术 | 118篇 |
技术理论 | 1篇 |
综合类 | 465篇 |
化学工业 | 104篇 |
金属工艺 | 66篇 |
机械仪表 | 348篇 |
建筑科学 | 148篇 |
矿业工程 | 26篇 |
能源动力 | 45篇 |
轻工业 | 41篇 |
水利工程 | 19篇 |
石油天然气 | 29篇 |
武器工业 | 26篇 |
无线电 | 737篇 |
一般工业技术 | 368篇 |
冶金工业 | 193篇 |
原子能技术 | 9篇 |
自动化技术 | 4116篇 |
出版年
2024年 | 36篇 |
2023年 | 132篇 |
2022年 | 175篇 |
2021年 | 266篇 |
2020年 | 247篇 |
2019年 | 214篇 |
2018年 | 205篇 |
2017年 | 236篇 |
2016年 | 315篇 |
2015年 | 292篇 |
2014年 | 351篇 |
2013年 | 325篇 |
2012年 | 286篇 |
2011年 | 310篇 |
2010年 | 215篇 |
2009年 | 251篇 |
2008年 | 310篇 |
2007年 | 264篇 |
2006年 | 271篇 |
2005年 | 254篇 |
2004年 | 232篇 |
2003年 | 174篇 |
2002年 | 174篇 |
2001年 | 143篇 |
2000年 | 164篇 |
1999年 | 109篇 |
1998年 | 107篇 |
1997年 | 115篇 |
1996年 | 83篇 |
1995年 | 98篇 |
1994年 | 87篇 |
1993年 | 63篇 |
1992年 | 75篇 |
1991年 | 59篇 |
1990年 | 40篇 |
1989年 | 34篇 |
1988年 | 22篇 |
1987年 | 13篇 |
1986年 | 20篇 |
1985年 | 23篇 |
1984年 | 16篇 |
1983年 | 9篇 |
1982年 | 11篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 2篇 |
排序方式: 共有6859条查询结果,搜索用时 18 毫秒
11.
Source number estimation and separation algorithms of underdetermined blind separation 总被引:2,自引:0,他引:2
YANG ZuYuan TAN BeiHai ZHOU GuoXu ZHANG JinLong 《中国科学F辑(英文版)》2008,(10):1623-1632
Recently, sparse component analysis (SCA) has become a hot spot in BSS research. Instead of independent component analysis (ICA), SCA can be used to solve underdetermined mixture efficiently. Two-step approach (TSA) is one of the typical methods to solve SCA based BSS problems. It estimates the mixing matrix before the separation of the sources. K-means clustering is often used to estimate the mixing matrix. It relies on the prior knowledge of the source number strongly. However, the estimation of the source number is an obstacle. In this paper, a fuzzy clustering method is proposed to estimate the source number and mixing matrix simultaneously. After that, the sources are recovered by the shortest path method (SPM). Simulations show the availability and robustness of the proposed method. 相似文献
12.
V. G. Tulchinsky A. K. Yushchenko R. A. Yushchenko 《Cybernetics and Systems Analysis》2008,44(2):292-303
A new visual language, which is called ER-QBE and uses a conceptual model semantics, is proposed for the development of XML
views. ER-QBE is based on graph queries that are trees of parametric SQL queries. The ER-QBE language is characterized by
formally proved completeness, its expressiveness is higher than that of well-known alternatives, and it supports both relational
and object-relational databases.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 171–183, March–April 2008. 相似文献
13.
Intelligence has been an object of study for a long time. Different architectures try to capture and reproduce these aspects into artificial systems (or agents), but there is still no agreement on how to integrate them into a general framework. With this objective in mind, we propose an architectural methodology based on the idea of intentional configuration of behaviors. Behavior‐producing modules are used as basic control components that are selected and modified dynamically according to the intentions of the agent. These intentions are influenced by the situation perceived, knowledge about the world, and internal variables that monitor the state of the agent. The architectural methodology preserves the emergence of functionality associated with the behavior‐based paradigm in the more abstract levels involved in configuring the behaviors. Validation of this architecture is done using a simulated world for mobile robots, in which the agent must deal with various goals such as managing its energy and its well‐being, finding targets, and acquiring knowledge about its environment. Fuzzy logic, a topologic map learning algorithm, and activation variables with a propagation mechanism are used to implement the architecture for this agent. 相似文献
14.
Robert Cummins 《Minds and Machines》1991,1(1):31-42
In response to Michael Morris, I attempt to refute the crucial second premise of the argument, which states that the formality condition cannot be satisfied non-stipulatively in computational systems. I defend the view of representation urged in Meaning and Mental Representation against the charge that it makes content stipulative and therefore irrelevant to the explanation of cognition. Some other reservations are expressed. 相似文献
15.
Hugh Clapin 《Minds and Machines》1991,1(2):167-184
Ramsey, Stich and Garon's recent paper Connectionism, Eliminativism, and the Future of Folk Psychology claims a certain style of connectionism to be the final nail in the coffin of folk psychology. I argue that their paper fails to show this, and that the style of connectionism they illustrate can in fact supplement, rather than compete with, the claims of a theory of cognition based in folk psychology's ontology. Ramsey, Stich and Garon's argument relies on the lack of easily identifiable symbols inside the connectionist network they discuss, and they suggest that the existence of a system which behaves in a cognitively interesting way, but which cannot be explained by appeal to internal symbol processing, falsifies central assumptions of folk psychology. My claim is that this argument is flawed, and that the theorist need not discard folk psychology in order to accept that the network illustrated exhibits cognitively interesting behaviour, even if it is conceded that symbols cannot be readily identified within the network.This paper was in part prepared whilst I was a Vacation Scholar at the Automated Reasoning Project, Australian National University. It was presented in its present form to the Department of Philosophy, Institute of Advanced Studies, ANU. I owe a deep gratitude to many people who read and commented on earlier drafts of this paper, especially Phillip Staines and Phillip Cam from UNSW, Ed Mares from the Automated Reasoning Project at the ANU, and Frank Jackson, Karen Neander and David Braddon-Mitchell from the Philosophy Department, IAS, ANU. All the paper's faults are, of course, mine. 相似文献
16.
徐青 《浙江理工大学学报》2013,30(4)
针对抗日战争时期日本媒体的战争责任的问题,文章以活跃于大正和昭和年间的日本大众女作家吉屋信子各时期文学作品中的上海表象为线索,以吉屋的现地报告《战祸的北支上海行》为关注的焦点,分析了吉屋文学世界里所凝视的上海表象是“虚伪错误”的,而她提倡的中日两国通力合作的“共同幻想”也只是空洞的现实认识的记录而已.随着此种幻想的不断扩张,日本大众对已有一定倾向性的“上海负面形象”的认识也得以进一步的扩大. 相似文献
17.
Hajime Yoshino 《Artificial Intelligence and Law》1997,5(1-2):77-96
In order to represent legal knowledge adequately, it is vital to create a formal device that can freely construct an individual concept directly from a predicate expression. For this purpose, a Compound Predicate Formula (CPF) is formulated for use in legal expert systems. In this paper, we willattempt to explain the nature of CPFs by rigorous logical foundation, i.e., establishing their syntax and semantics precisely through the use of appropriate examples. We note the advantages of our system over other such systems and discuss the significance of CPFs with regard to the formalization of legal reasonings using examples from the United Nations Convention for the International Sale of Goods. 相似文献
18.
Signed Systems for Paraconsistent Reasoning 总被引:3,自引:0,他引:3
We present a novel approach to paraconsistent reasoning, that is, to reasoning from inconsistent information. The basic idea is the following. We transform an inconsistent theory into a consistent one by renaming all literals occurring in the theory. Then, we restore some of the original contents of the theory by introducing progressively formal equivalences linking the original literals to their renamings. This is done as long as consistency is preserved. The restoration of the original contents of the theory is done by appeal to default logic. The overall approach provides us with a family of paraconsistent consequence relations.Our approach is semantical because it works at the level of the propositions; it deals with the semantical link between a proposition and its negation. The approach is therefore independent of the combination of the connectives that are actually applied to the propositions in order to form entire formulas. 相似文献
19.
Knowledge-based computing, in general, suffers from an inherent open-endedness that precludes its application in time-bounded domains where an answer must be computed within a stipulated time limit. We examine a two-way improvement of the shortcomings: a knowledge representation scheme that provides easy access to relevant knowledge and thereby reduces search time, and a reasoning scheme that is algorithmic in nature and thus makes computational requirements meaningfully estimable.In this work, we offer a cache-based architecture that is capable of both storing knowledge in different formats (e.g. rules, cases), and invoking an appropriate reasoning scheme to fit the available computing time. The cache helps in retrieving the most relevant pieces of knowledge (not only exact matches) required for solving a given problem. This cache relies on a reasoning tactic, knowledge interpolation, that can generate a solution from two near-matches in an algorithmic way, to generate time-bounded solutions. We illustrate the design of such a cache for solving resource allocation problems in the domain of shortwave radio transmission and evaluate its performance in observing imposed temporal bounds. 相似文献
20.
Horizon control, maintaining the alignment of the shearer’s exploitation gradient with the coal seam gradient, is a key technique in longwall mining automation. To identify the coal seam gradient, a geological model of the coal seam was constructed using in-seam seismic surveying technology. By synthesizing the control resolution of the range arm and the geometric characteristics of the coal seam, a gradient identification method based on piecewise linear representation(PLR) is proposed. To achi... 相似文献