全文获取类型
收费全文 | 7141篇 |
免费 | 1001篇 |
国内免费 | 838篇 |
专业分类
电工技术 | 670篇 |
综合类 | 797篇 |
化学工业 | 371篇 |
金属工艺 | 123篇 |
机械仪表 | 305篇 |
建筑科学 | 517篇 |
矿业工程 | 133篇 |
能源动力 | 154篇 |
轻工业 | 133篇 |
水利工程 | 287篇 |
石油天然气 | 191篇 |
武器工业 | 85篇 |
无线电 | 805篇 |
一般工业技术 | 505篇 |
冶金工业 | 124篇 |
原子能技术 | 66篇 |
自动化技术 | 3714篇 |
出版年
2024年 | 15篇 |
2023年 | 102篇 |
2022年 | 116篇 |
2021年 | 147篇 |
2020年 | 150篇 |
2019年 | 210篇 |
2018年 | 153篇 |
2017年 | 215篇 |
2016年 | 243篇 |
2015年 | 273篇 |
2014年 | 385篇 |
2013年 | 449篇 |
2012年 | 503篇 |
2011年 | 528篇 |
2010年 | 424篇 |
2009年 | 493篇 |
2008年 | 544篇 |
2007年 | 641篇 |
2006年 | 490篇 |
2005年 | 459篇 |
2004年 | 366篇 |
2003年 | 309篇 |
2002年 | 274篇 |
2001年 | 210篇 |
2000年 | 184篇 |
1999年 | 171篇 |
1998年 | 138篇 |
1997年 | 133篇 |
1996年 | 116篇 |
1995年 | 91篇 |
1994年 | 100篇 |
1993年 | 70篇 |
1992年 | 54篇 |
1991年 | 53篇 |
1990年 | 22篇 |
1989年 | 31篇 |
1988年 | 22篇 |
1987年 | 15篇 |
1986年 | 6篇 |
1985年 | 15篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1962年 | 2篇 |
排序方式: 共有8980条查询结果,搜索用时 31 毫秒
141.
Distributed average computation for multiple time‐varying signals with output measurements
下载免费PDF全文
![点击此处可从《国际强度与非线性控制杂志<br>》网站下载免费的PDF全文](/ch/ext_images/free.gif)
This paper studies the distributed average computation problem for multiple time‐varying signals with bounded inputs. Based only on relative output measurements, a pair of continuous algorithms with, respectively, static and adaptive coupling strengths are designed and utilized. From the concept of boundary layer approach, the proposed continuous algorithm with static coupling strengths can asymptotically obtain the average value of the multiple reference signals without chattering phenomenon. Furthermore, for the case of algorithms with adaptive coupling strengths, the calculation errors are uniformly ultimately bounded and exponentially converge to a small adjustable bounded set. Finally, a simulation example is presented to show the validity of the theoretical results. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
142.
Optimal representation of acoustic features is an ongoing challenge in automatic speech recognition research. As an initial step toward this purpose, optimization of filterbanks for the cepstral coefficient using evolutionary optimization methods is proposed in some approaches. However, the large number of optimization parameters required by a filterbank makes it difficult to guarantee that an individual optimized filterbank can provide the best representation for phoneme classification. Moreover, in many cases, a number of potential solutions are obtained. Each solution presents discrimination between specific groups of phonemes. In other words, each filterbank has its own particular advantage. Therefore, the aggregation of the discriminative information provided by filterbanks is demanding challenging task. In this study, the optimization of a number of complementary filterbanks is considered to provide a different representation of speech signals for phoneme classification using the hidden Markov model (HMM). Fuzzy information fusion is used to aggregate the decisions provided by HMMs. Fuzzy theory can effectively handle the uncertainties of classifiers trained with different representations of speech data. In this study, the output of the HMM classifiers of each expert is fused using a fuzzy decision fusion scheme. The decision fusion employed a global and local confidence measurement to formulate the reliability of each classifier based on both the global and local context when making overall decisions. Experiments were conducted based on clean and noisy phonetic samples. The proposed method outperformed conventional Mel frequency cepstral coefficients under both conditions in terms of overall phoneme classification accuracy. The fuzzy fusion scheme was shown to be capable of the aggregation of complementary information provided by each filterbank. 相似文献
143.
在机器人路径规划的实际应用中,针对机器人移动行为可能会受到外界环境影响的难题,提出了一种采用概率模型检测技术进行路径规划的新方法。首先,分析环境中的主要影响因素,将机器人的移动行为看作一个不确定事件,构建马尔可夫决策过程(MDP)模型。然后,采用概率计算树逻辑(PCTL)公式描述模型属性,表达机器人复杂多样的目标任务。最后,运用PRISM平台对模型进行分析和验证,得到满足属性的全局优化路径和定量数据。仿真结果表明,上述方法不仅能够保障机器人在障碍物环境中无碰撞移动,而且可以避开环境相对复杂的区域,保证机器人以最大概率完成任务。对比试验证明上述方法的正确性和有效性。 相似文献
144.
多表达式程序设计(MEP)是应用十分广泛的自动程序设计方法。从MEP的染色体表示规则及种群演化方式来看,每个染色体中的任何基因都有可能多次被当前或其它后续种群中的其他基因引用,从而造成重复计算,耗费大量时空资源。由此提出并实现了一种新型评估方法,该新型评估方法在不改变传统MEP的染色体表示规则和种群演化方式的情况下,能够准确有效地识别演化过程中所有被重复引用的基因,从而避免了大量重复计算,显著提高了演化效率。 相似文献
145.
Francesca Franco 《Digital Creativity》2013,24(3):222-236
This article focuses on the experience of British artist Ernest Edmonds and the influences that have informed his art practice in the past forty years. How are these influences connected? The article has an historical focus. It develops the themes within Edmonds's art and shows his connections with the ‘Systems’ artists and their forebears. In particular, the article concentrates on the encounter of Edmonds with artistic thinking about systems and process in the broad sense, as well as digital and interactive work developed from the early 1980s. As the article will demonstrate, a passion for colour, time and structure, the encounter with a number of artists inspired by Constructivism in the early 1980s, and the educational context in which Edmonds has worked from the late 1960s until the present, have offered great opportunities of interdisciplinary exchanges and ideas that had a profound impact upon the nature of his art. These influences have enabled Edmonds to explore new constructs in art through the use of technology that are a constant stimulus in his creative research, both as an artist and as an academic. 相似文献
146.
147.
青海省公路桥涵水文分区方法与指标研究 总被引:1,自引:0,他引:1
介绍了青海省公路桥涵水文分区的现状,通过分析河流的水情变化,论证了修正现行水文分区的必要性,并结合青海省河流的特殊性,对比了省内外一些典型的水文区划方法及水文因子。结果表明:①应根据流域水系、内外流区、沙漠面积等定性指标,以原水文分区为一级区划,在其基础上进行修正并确定二级分区;②利用河川径流强度指标法进行分区划分时,分区指标为年平均降水量、岩土类型、河网密度和沟谷比重;③利用模糊聚类法进行分区划分时,分区指标为年平均径流深、年平均降水量、气候带、河流补给形式及单位面积上50 a一遇设计流量,但只有黄河上游区、湟水大通河区可使用该方法;④青海省内沙漠面积较大,在分区时可将其划分为非产流区。 相似文献
148.
MoCap(motion capture)-based animation is a hot issue in computer animation research currently.Based on the optical MoCap system,this paper proposes a novel cross-mapping based facial expression simulating method.To overcome the problem of the false upper and lower jaw correlation derived from the facial global RBFbased cross-mapping method,we construct a functional partition based RBF cross-mapping method.During model animating,enhanced markers are added and animated by our proposed skin motion mechanism.In addition,based on the enhanced markers,an improved RBF-based animating approach is raised to derive realistic facial animation.Further more,a pre-computing algorithm is presented to reduce computational cost for real-time simulation.The experiments proved that the method can not only map the MoCap data of one subject to diferent personalized faces but generate realistic facial animation. 相似文献
149.
将多值逻辑系统Hα(0≤α≤1)中的广义重言式理论进行推广,讨论其序稠密子代数的广义重言式理论,利用可达广义重言式概念在系统H1/2的序稠密子代数中给出F(S)的一个分划,并把系统H1/2中的相关结论推广到系统Hα(0≤α≤1)中。 相似文献
150.
介绍了多操作系统安装的必要性,分析了计算机的启动过程,结合运用常用的磁盘分区工具,对硬盘分出多个主分区和扩展分区,利用GAG系统引导管理软件,在计算机启动时激活不同的主分区,从而达到启动不同操作系统的目的。另外还介绍了系统的维护和一些注意事项。 相似文献