全文获取类型
收费全文 | 59771篇 |
免费 | 2432篇 |
国内免费 | 1569篇 |
专业分类
电工技术 | 1881篇 |
技术理论 | 1篇 |
综合类 | 3097篇 |
化学工业 | 4924篇 |
金属工艺 | 4284篇 |
机械仪表 | 8709篇 |
建筑科学 | 2460篇 |
矿业工程 | 1226篇 |
能源动力 | 5373篇 |
轻工业 | 910篇 |
水利工程 | 355篇 |
石油天然气 | 731篇 |
武器工业 | 581篇 |
无线电 | 3452篇 |
一般工业技术 | 4402篇 |
冶金工业 | 1780篇 |
原子能技术 | 669篇 |
自动化技术 | 18937篇 |
出版年
2024年 | 298篇 |
2023年 | 490篇 |
2022年 | 645篇 |
2021年 | 796篇 |
2020年 | 875篇 |
2019年 | 757篇 |
2018年 | 817篇 |
2017年 | 1070篇 |
2016年 | 1153篇 |
2015年 | 1470篇 |
2014年 | 2604篇 |
2013年 | 2613篇 |
2012年 | 2840篇 |
2011年 | 4250篇 |
2010年 | 2834篇 |
2009年 | 3113篇 |
2008年 | 3094篇 |
2007年 | 3882篇 |
2006年 | 3614篇 |
2005年 | 3556篇 |
2004年 | 3170篇 |
2003年 | 3170篇 |
2002年 | 2625篇 |
2001年 | 1980篇 |
2000年 | 1938篇 |
1999年 | 1712篇 |
1998年 | 1588篇 |
1997年 | 1261篇 |
1996年 | 1102篇 |
1995年 | 849篇 |
1994年 | 684篇 |
1993年 | 577篇 |
1992年 | 451篇 |
1991年 | 391篇 |
1990年 | 266篇 |
1989年 | 229篇 |
1988年 | 238篇 |
1987年 | 142篇 |
1986年 | 105篇 |
1985年 | 112篇 |
1984年 | 113篇 |
1983年 | 70篇 |
1982年 | 44篇 |
1981年 | 49篇 |
1980年 | 20篇 |
1979年 | 29篇 |
1978年 | 15篇 |
1977年 | 23篇 |
1976年 | 20篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Christopher Rasmussen 《Autonomous Robots》2008,25(3):205-229
We present a vision- and ladar-based approach to autonomous driving on rural and desert roads that has been tested extensively
in a closed-loop system. The vision component uses Gabor wavelet filters for texture analysis to find ruts and tracks from
which the road vanishing point can be inferred via Hough-style voting, yielding a direction estimate for steering control.
The ladar component projects detected obstacles along the road direction onto the plane of the front of the vehicle and tracks
the 1-D obstacle “gap” presumed due to the road to yield a lateral offset estimate. Several image- and state-based tests to
detect failure conditions such as off-road poses (i.e., there is no road to follow) and poor lighting due to sun glare or
distracting shadows are also explained. The system’s efficacy is demonstrated with analysis of diverse logged data including
from the 2005 DARPA Grand Challenge, as well as tests with full control of a vehicle over 15 km of difficult roads at up to
37 km/h with no waypoints.
相似文献
Christopher RasmussenEmail: |
82.
本文针对计算机专业学生学习计算机算法语言存在的问题,引用互动式教学的理论,设计了互动式教学模式,即"建-仿-读-改-写",提出了互动式教学的环境要求,分析了互动式教学的教学效果,基本形成了一套完整的教学方案。对提高计算机专业教学效果具有一定的指导意义。 相似文献
83.
入侵容忍系统的安全性量化方法分析 总被引:1,自引:0,他引:1
入侵容忍系统的安全性量化评估技术目前已取得了初步研究成果。本文首先简要阐述该技术的进展情况,然后从构建安全模型和分析攻击行为两大方面,横向比较了目前国内外在该领域的研究成果,并进行总结和分析,提出了一些未来的研究设想。 相似文献
84.
85.
随着Web信息的急剧增长使搜索引擎专用化成为发展趋势.根据当前的需求提出了实现建筑业信息搜索引擎设计方法.重点论述主题搜索引擎的信息采集策略,并给出了一种比较理想的建筑业信息搜索引擎设计方案. 相似文献
86.
This authors of this article investigated the dynamic response of woven Kevlar®29/epoxy laminates subjected to the impact loading. The cylindrical aluminum foam projectile and steel projectile were used to exert the impulse on the laminates. Deformation/failure modes, deflections, strain histories, and failure mechanisms were obtained and discussed. The results showed that with the high toughness of Kevlar fiber, the deformation modes of the laminates exhibited some characteristics similar to the metal panel, such as large global deformation. The failure mechanisms like matrix failure, fiber splitting, and fibrillation were observed. These micron failures led to the macroscopic delamination and fracture of the laminates. 相似文献
87.
88.
本文结合我校教学的实际情况,探讨了计算机信息管理系统课程实践教学的改革,主要包括"三阶段"的技术要求、"企业化"的分组管理、"过程化"的项目运行和"合理化"的考核评价办法。 相似文献
89.
Julián D. Arias-Londoño Author Vitae Juan I. Godino-Llorente Author Vitae Nicolás Sáenz-Lechón Author Vitae Author Vitae Germán Castellanos-Domínguez Author Vitae 《Pattern recognition》2010,43(9):3100-3112
This paper presents new a feature transformation technique applied to improve the screening accuracy for the automatic detection of pathological voices. The statistical transformation is based on Hidden Markov Models, obtaining a transformation and classification stage simultaneously and adjusting the parameters of the model with a criterion that minimizes the classification error. The original feature vectors are built up using classic short-term noise parameters and mel-frequency cepstral coefficients. With respect to conventional approaches found in the literature of automatic detection of pathological voices, the proposed feature space transformation technique demonstrates a significant improvement of the performance with no addition of new features to the original input space. In view of the results, it is expected that this technique could provide good results in other areas such as speaker verification and/or identification. 相似文献
90.
The present study investigates the impact of the experience of role playing a violent character in a video game on attitudes towards violent crimes and criminals. People who played the violent game were found to be more acceptable of crimes and criminals compared to people who did not play the violent game. More importantly, interaction effects were found such that people were more acceptable of crimes and criminals outside the game if the criminals were matched with the role they played in the game and the criminal actions were similar to the activities they perpetrated during the game. The results indicate that people’s virtual experience through role-playing games can influence their attitudes and judgments of similar real-life crimes, especially if the crimes are similar to what they conducted while playing games. Theoretical and practical implications are discussed. 相似文献