全文获取类型
收费全文 | 19484篇 |
免费 | 1383篇 |
国内免费 | 1141篇 |
专业分类
电工技术 | 1660篇 |
技术理论 | 3篇 |
综合类 | 1581篇 |
化学工业 | 359篇 |
金属工艺 | 662篇 |
机械仪表 | 1901篇 |
建筑科学 | 435篇 |
矿业工程 | 444篇 |
能源动力 | 385篇 |
轻工业 | 192篇 |
水利工程 | 129篇 |
石油天然气 | 230篇 |
武器工业 | 239篇 |
无线电 | 1989篇 |
一般工业技术 | 769篇 |
冶金工业 | 267篇 |
原子能技术 | 108篇 |
自动化技术 | 10655篇 |
出版年
2024年 | 30篇 |
2023年 | 87篇 |
2022年 | 179篇 |
2021年 | 224篇 |
2020年 | 295篇 |
2019年 | 320篇 |
2018年 | 269篇 |
2017年 | 395篇 |
2016年 | 487篇 |
2015年 | 608篇 |
2014年 | 972篇 |
2013年 | 1019篇 |
2012年 | 1043篇 |
2011年 | 1270篇 |
2010年 | 1014篇 |
2009年 | 1203篇 |
2008年 | 1301篇 |
2007年 | 1492篇 |
2006年 | 1467篇 |
2005年 | 1282篇 |
2004年 | 1078篇 |
2003年 | 985篇 |
2002年 | 768篇 |
2001年 | 683篇 |
2000年 | 582篇 |
1999年 | 554篇 |
1998年 | 466篇 |
1997年 | 400篇 |
1996年 | 324篇 |
1995年 | 275篇 |
1994年 | 236篇 |
1993年 | 162篇 |
1992年 | 122篇 |
1991年 | 97篇 |
1990年 | 59篇 |
1989年 | 63篇 |
1988年 | 42篇 |
1987年 | 26篇 |
1986年 | 27篇 |
1985年 | 28篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1973年 | 3篇 |
1957年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
关于Vague集的模糊熵及其构造 总被引:17,自引:3,他引:14
本文分析了Vague集的性质,给出了将Vague集变换为Fuzzy集的转换函数,并讨论了其性质。分析了关于Vague集的模糊熵的直观特性,在此基础上我们给出了Vague集的模糊熵的定义。最后给出了一个关于Vague集的模糊熵的构造方法。 相似文献
82.
数字工流量阀采用数字控制方式,调节系统流量以达到液压系统调整目的,它本身具有控制响应快、精度高、稳定性好、适应范围大等优点,在行走机械上将会得到广泛地应用。 相似文献
83.
介绍了一种用可编程控制器(PLC)实现捆扎机自动控制的设计方案,详细地介绍了设计过程,给出了完整的程序流程图和部分控制程序。 相似文献
84.
85.
Matthew Huntbach 《International journal of parallel programming》1991,20(4):299-314
The concurrent logic languages, of which Parlog is one, have been promoted as a new generation of software languages specifically designed for parallel programming. This paper investigates their application to a search problem commonly used as an illustration of artificial intelligence techniques, the 8-puzzle. It notes that programs written in the concurrent logic languages which do not pay attention to the parallelism can fall into two possible traps: either there is little real parallelism in them due to data dependencies, or there is too much parallelism and any practical architecture will be overwhelmed. A solution which controls the parallelism using user-defined priorities is proposed. This solution has the advantage of being architecture-independent. 相似文献
86.
The hierarchies of knowledge and the mathematics of discovery 总被引:1,自引:1,他引:0
Clark Glymour 《Minds and Machines》1991,1(1):75-95
Rather than attempting to characterize a relation of confirmation between evidence and theory, epistemology might better consider which methods of forming conjectures from evidence, or of altering beliefs in the light of evidence, are most reliable for getting to the truth. A logical framework for such a study was constructed in the early 1960s by E. Mark Gold and Hilary Putnam. This essay describes some of the results that have been obtained in that framework and their significance for philosophy of science, artificial intelligence, and for normative epistemology when truth is relative.I am indebted to Kevin Kelly for several years of happy conversation from which the perspective and views of this paper grew, for comments on a draft of the paper, and for constructing some of the illustrations. A fellowship from the John Simon Guggenheim Memorial Foundation provided the liberty to write this paper. It was first presented in the Turing Colloquium, 1990. 相似文献
87.
Optimal solutions of several variants of the probabilistic reasoning problem were found by a new technique that integrates
integer programming and probabilistic deduction graphs (PDG). PDGs are extended from deduction graphs of the and-type via
normal deduction graphs. The foregoing variants to be solved can involve multiple hypotheses and multiple evidences where
the former is given and the latter is unknown and being found or vice versa. The relationship among these hypotheses and evidences
with possible intermediaries is represented by a causal graph. The proposed method can handle a large causal graph of any
type and find an optimal solution by invoking a linear integer programming package. In addition, formulating the reasoning
problem to fit integer programming takes a polynomial time.
H.-L. Li was visiting the Department of Computer Sciences, University of North Texas in 1988–1989. He is with the Institute
of Information Management, National Chiao Tung University, Hsinchu, Taiwan, R.O.C. 相似文献
88.
模式识别催化剂生产调优 总被引:2,自引:0,他引:2
王景芳 《计算机与应用化学》1992,9(4):260-266
本文介绍如何将模式识别应用于生产调优,着重讨论了多指标(优化目标)因素的分级,提出了用模糊综合评价度量和依有序聚类最小损失函数准则划类,并相继进行变量与样本筛选、信息压缩、特征提取和模拟仿真获得优区操作条件,实施效果显著。 相似文献
89.
Silvano Dal Zilio Denis Lugiez 《Applicable Algebra in Engineering, Communication and Computing》2006,17(5):337-377
XML documents may be roughly described as unranked, ordered trees and it is therefore natural to use tree automata to process or validate them. This idea has already been successfully applied in the context of Document Type Definition (DTD), the simplest standard for defining document validity, but additional work is needed to take into account XML Schema, a more advanced standard, for which regular tree automata are not satisfactory. In this paper, we introduce Sheaves Logic (SL), a new tree logic that extends the syntax of the – recursion-free fragment of – W3C XML Schema Definition Language (WXS). Then, we define a new class of automata for unranked trees that provides decision procedures for the basic questions about SL: model-checking; satisfiability; entailment. The same class of automata is also used to answer basic questions about WXS, including recursive schemas: decidability of type-checking documents; testing the emptiness of schemas; testing that a schema subsumes another one.This work was partially supported by the French government research grant ACI TRALALA and by IST Global Computing Profundis. 相似文献
90.
T. Bag 《Information Sciences》2006,176(19):2910-2931
In this paper, definitions of strongly fuzzy convergent sequence, l-fuzzy weakly convergent sequence and l-fuzzy weakly compact set are given in a fuzzy normed linear space. The concepts of fuzzy normal structure, fuzzy non-expansive mapping, uniformly convex fuzzy normed linear space are introduced and fixed point theorems for fuzzy non-expansive mappings are proved. 相似文献