全文获取类型
收费全文 | 21967篇 |
免费 | 3425篇 |
国内免费 | 1609篇 |
专业分类
电工技术 | 2992篇 |
技术理论 | 2篇 |
综合类 | 2182篇 |
化学工业 | 2686篇 |
金属工艺 | 782篇 |
机械仪表 | 1148篇 |
建筑科学 | 4684篇 |
矿业工程 | 657篇 |
能源动力 | 917篇 |
轻工业 | 363篇 |
水利工程 | 915篇 |
石油天然气 | 200篇 |
武器工业 | 155篇 |
无线电 | 2016篇 |
一般工业技术 | 2834篇 |
冶金工业 | 471篇 |
原子能技术 | 137篇 |
自动化技术 | 3860篇 |
出版年
2024年 | 101篇 |
2023年 | 632篇 |
2022年 | 906篇 |
2021年 | 1067篇 |
2020年 | 1124篇 |
2019年 | 921篇 |
2018年 | 798篇 |
2017年 | 936篇 |
2016年 | 899篇 |
2015年 | 1011篇 |
2014年 | 1520篇 |
2013年 | 1414篇 |
2012年 | 1611篇 |
2011年 | 1767篇 |
2010年 | 1432篇 |
2009年 | 1426篇 |
2008年 | 1360篇 |
2007年 | 1545篇 |
2006年 | 1235篇 |
2005年 | 1069篇 |
2004年 | 860篇 |
2003年 | 673篇 |
2002年 | 571篇 |
2001年 | 431篇 |
2000年 | 355篇 |
1999年 | 294篇 |
1998年 | 165篇 |
1997年 | 168篇 |
1996年 | 122篇 |
1995年 | 107篇 |
1994年 | 88篇 |
1993年 | 67篇 |
1992年 | 62篇 |
1991年 | 49篇 |
1990年 | 26篇 |
1989年 | 30篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1982年 | 6篇 |
1980年 | 12篇 |
1977年 | 4篇 |
1966年 | 6篇 |
1965年 | 9篇 |
1964年 | 17篇 |
1963年 | 12篇 |
1961年 | 8篇 |
1960年 | 6篇 |
1959年 | 6篇 |
1958年 | 5篇 |
1955年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Kotaro Matsuuchi Tadashi Fukami Nobuyuki Naoe Ryoichi Hanaoka Shinzo Takata Toshio Miyamoto 《Electrical Engineering in Japan》2005,150(2):43-49
This paper presents a method of predicting the steady‐state performance of a new hybrid‐excitation synchronous machine (HESM) theoretically. The field pole of this HESM is axially divided into two parts; one is an excitation part and the other a permanent‐magnet (PM) part. A nonlinear equivalent circuit, which can include the saliency of the rotor and the magnetic saturation due to the iron core, is derived. Based on this equivalent circuit, the steady‐state performance of the HESM is calculated, and the results are confirmed through experiments. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(2): 43–49, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20033 相似文献
62.
This paper proposed a novel hybrid probabilistic network, which is a good tradeoff between the model complexity and learnability
in practice. It relaxes the conditional independence assumptions of Naive Bayes while still permitting efficient inference
and learning. Experimental studies on a set of natural domains prove its clear advantages with respect to the generalization
ability. 相似文献
63.
64.
本文研究当机械臂的终端受有约束时的控制问题,其中心内容是给出“任务规范投影算子”的概念,利用它首先将机械臂的动态方程解耦为两组方程,它们分别描述了运动与约束力,在此基础上给出了机械臂的控制律,使闭环系统跟踪期望的速度与约束力。 相似文献
65.
Voucher-based reinforcement therapy (VBRT) is an effective drug abuse treatment, but the cost of VBRT rewards has limited its dissemination. Obtaining VBRT incentives through donations may be one way to overcome this barrier. Two direct mail campaigns solicited donations for use in VBRT for pregnant, postpartum, and parenting drug users in Toronto, Ontario, Canada, and in Los Angeles, California. In Toronto, 19% of those contacted over 2 months donated $8,000 ($4,000/month) of goods and services. In Los Angeles, nearly 26% of those contacted over 34 months donated $161,000 ($4,472/month) of goods and services. Maintaining voucher programs by soliciting donations is feasible and sustainable. The methods in this article can serve as a guide for successful donation solicitation campaigns. Donations offer an alternative for obtaining VBRT rewards for substance abuse treatment and may increase its dissemination. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
隧道受震破壞調查分析與修復管理案例 总被引:1,自引:0,他引:1
就隧道震後之災損模式進行統計與災損原因研判,並利用數值分析方法研判安全性,就結構加固等改善措施之設計考量作詳細說明;另由於隧道結構物的損壞範圍大,且修復經費受限,必須藉由定期檢测進行長期維護管理,以防範意外發生。於此,利用Vidco-GIS自動化影像地理资訊系統之e化新技術,以動態及靜態影像紀錄隧道災損狀況,同時亦整合建置前期設計、施工圖及定期維護等資料,相關成果以資料庫方式纳入日常維護管理,以有限人力有效率地進行維護管理紀錄並随時掌握現況供作決策之明確參考。 相似文献
67.
本文着重对图象多分辨率技术进行分析,并提出了相应的系统结构成框架,同时还探讨了以图象多分辨率处理为核心,采用了 新的压缩编码的可能性。 相似文献
68.
混合微电子技术,推动了整个电子工业的发展。从市场和技术两个方面评述这种发展态势,重点介绍先进混合集成技术。 相似文献
69.
岳城水库供水工程, 邯郸、安阳两城市引水岔管均采用内、外贴边补强板型式对取水口进行局部加强。此补强方法对水流流态干扰较少, 水头损失小。设置这样的岔管对原电站压力钢管结构改动较小, 构造相对简单, 制作与安装方便, 对岳城水库供水这样的改建工程较为适用。 相似文献
70.
How to Control Robots Interacting with Dynamic Environment 总被引:7,自引:0,他引:7
Miomir Vukobratović 《Journal of Intelligent and Robotic Systems》1997,19(2):119-152
The goal of this paper is to shed light on the control problem of constrained robot motion from the aspect of the dynamical nature of the environment with which the robot is in contact. Therefore, the criticism of traditional hybrid control which allows position/force feedback loops to split into independent control with respect to position and force, is not the main point we want to make. Reference to the papers written by the founders of hybrid control and their numerous followers served only to better understand the reason and motivation for suggesting a different approach to control of robots interacting with environment.The paper has a predominantly review character, based on recently published work. It also contains some new, unpublished results in the framework of the unified approach to the position/force control of robots, proposed by the present author and his co-workers. By pointing to the possibility of introducing an environment dynamics in the contact tasks of the machining type, the author emphasizes that the proposed dynamically interactive control can be applied to a completely different class of tasks, in which a contact is made between the system (constructions or structure) and very specific kinds of dynamic environments. 相似文献