全文获取类型
收费全文 | 10360篇 |
免费 | 748篇 |
国内免费 | 354篇 |
专业分类
电工技术 | 469篇 |
综合类 | 458篇 |
化学工业 | 1828篇 |
金属工艺 | 547篇 |
机械仪表 | 495篇 |
建筑科学 | 714篇 |
矿业工程 | 203篇 |
能源动力 | 340篇 |
轻工业 | 681篇 |
水利工程 | 135篇 |
石油天然气 | 379篇 |
武器工业 | 39篇 |
无线电 | 1598篇 |
一般工业技术 | 1445篇 |
冶金工业 | 747篇 |
原子能技术 | 83篇 |
自动化技术 | 1301篇 |
出版年
2024年 | 36篇 |
2023年 | 158篇 |
2022年 | 296篇 |
2021年 | 402篇 |
2020年 | 256篇 |
2019年 | 230篇 |
2018年 | 305篇 |
2017年 | 295篇 |
2016年 | 293篇 |
2015年 | 296篇 |
2014年 | 433篇 |
2013年 | 630篇 |
2012年 | 580篇 |
2011年 | 704篇 |
2010年 | 602篇 |
2009年 | 560篇 |
2008年 | 614篇 |
2007年 | 520篇 |
2006年 | 525篇 |
2005年 | 371篇 |
2004年 | 320篇 |
2003年 | 323篇 |
2002年 | 304篇 |
2001年 | 263篇 |
2000年 | 246篇 |
1999年 | 262篇 |
1998年 | 302篇 |
1997年 | 234篇 |
1996年 | 231篇 |
1995年 | 173篇 |
1994年 | 150篇 |
1993年 | 108篇 |
1992年 | 69篇 |
1991年 | 56篇 |
1990年 | 46篇 |
1989年 | 43篇 |
1988年 | 36篇 |
1987年 | 30篇 |
1986年 | 26篇 |
1985年 | 16篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 16篇 |
1979年 | 13篇 |
1978年 | 7篇 |
1976年 | 13篇 |
1975年 | 9篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
We have previously introduced [2, 5] a neural implementation of Canonical Correlation Analysis (CCA). In this paper, we re-derive the learning method from a probabilistic perspective and then show that similar networks can be derived based on the pioneering work of Becker [1] if certain simplifying assumptions are made. Becker has shown that her network is able to find depth information from an abstraction of random dot stereogram data and so finally we note the similarity of the derived methods with those of Stone [3] which was used with a smooth stereo disparity data set to extract depth information. 相似文献
993.
Zhong-Qi Cai Ying-Sheng Luo Yu-Chi Lai Chih-Shiang Chan Wen-Kai Tai 《Computer Graphics Forum》2020,39(1):50-62
Pailous are representative Chinese architectural works used for commemoration. However, their geometric structure and semantic construction rules are too complex for quick and intuitive modelling using traditional modelling tools. We propose an intuitive modelling system for the stylized creation of pailous for novices. Our system encapsulates structural components as icons and semantic layouts as topological graphs, using which users create and manipulate icons with topological recommendations. The interpreter automatically and immediately transforms a graph to its corresponding model using built-in components with the proposed parametric L-system grammars derived from architectural rules. Using this system to re-create existing representative pailous and design imaginary ones yields results with the desired visual complexities. In comparison to Maya, a 3D modelling tool, when modelling a pailou and toukung, our system is effective and simple, and eliminates the need to remember and understand complex rules. 相似文献
994.
995.
A discrete replacement model is presented that includes a cumulative repair cost limit for a two-unit system with failure rate interactions between the units. We assume a failure in unit 1 causes the failure rate in unit 2 to increase, whereas a failure in unit 2 causes a failure in unit 1, resulting in a total system failure. If unit 1 fails and the cumulative repair cost till to this failure is less than a limit L, then unit 1 is repaired. If there is a failure in unit 1 and the cumulative repair cost exceeds L or the number of failures equals n, the entire system is preventively replaced. The system is also replaced at a total failure, and such replacement cost is higher than the preventive replacement cost. The long-term expected cost per unit time is derived using the expected costs as the optimality criterion. The minimum-cost policy is derived, and existence and uniqueness are proved. 相似文献
996.
山区城市具有市区地势低平,周边高的地理特征,而相应也具有复杂的无线传播环境,研究无线网络规划一般原则的基础上,针对山区城市进行WCDMA的网络规划仿真设计,并对仿真结果进行了分析. 相似文献
997.
998.
基于流形距离的半监督判别分析 总被引:5,自引:0,他引:5
大量无类别标签的数据具有对分类有用的信息,有效地利用这些信息来提高分类精确度,是半监督分类研究的主要内容.提出了一种基于流形距离的半监督判别分析(semi-supervised discriminant analysis based on manifold distance,简称SSDA)算法,通过定义的流形距离,能够选择位于流形上的数据点的同类近邻点、异类近邻点以及全局近邻点,并依据流形距离定义数据点与其各近邻点之间的相似度,利用这种相似度度量构造算法的目标函数.通过在ORL,YALE人脸数据库上的实验表明,与现有算法相比,数据集通过该算法降维后,能够使基于距离的识别算法具有更高的分类精确度.同时,为了解决非线性降维问题,提出了Kernel SSDA,同样通过实验验证了算法的有效性. 相似文献
999.
本文提出一种基于操作系统容器虚拟化技术的日志备份系统(Journaling Backup System,JBS)模型,该模型可用于软件审查,入侵检测,分析和系统恢复等方面。JBS模型主要的功能为监测软件交互过程并生成事务日志和对系统资源进行隔离。本文基于Linux-Vserver平台实现虚拟化容器技术,支持不同硬件平台,经过一系列系统调用测试,基于JBS模型的虚拟化容器所产生的系统调用数量远低本地系统,实验证明本文提出的JBS模型,降低了需要被监测系统调用的数量,提高系统监测性能。 相似文献
1000.
Jennifer Lai Stella Mitchell Christopher Pavlovski 《International Journal of Speech Technology》2007,10(1):17-30
As Third Generation (3G) networks emerge they provide not only higher data transmission rates but also the ability to transmit
both voice and low latency data within the same session. This paper describes the architecture and implementation of a multimodal
application (voice and text) that uses natural language understanding combined with a WAP browser to access email messages
on a cell phone. We present results from the use of the system by users as part of a laboratory trial that evaluated usage.
The user trial also compared the multimodal system with a text-only system that is representative of current products in the
market today. We discuss the observed modality issues and highlight implementation problems and usability concerns that were
encountered in the trial. Findings indicate that speech was used the majority of the time by participants for both input and
navigation even though most of the participants had little or no prior experience with speech systems (yet did have prior
experience with text-only access to applications on their phones). To our knowledge this represents the first implementation
and evaluation of its kind using this combination of technologies on an unmodified cell phone. Design implications resulting
from the study findings and usability issues encountered are presented to inform the design of future conversational multimodal
mobile applications. 相似文献