全文获取类型
收费全文 | 9798篇 |
免费 | 929篇 |
国内免费 | 564篇 |
专业分类
电工技术 | 2466篇 |
综合类 | 700篇 |
化学工业 | 345篇 |
金属工艺 | 220篇 |
机械仪表 | 580篇 |
建筑科学 | 333篇 |
矿业工程 | 437篇 |
能源动力 | 131篇 |
轻工业 | 175篇 |
水利工程 | 463篇 |
石油天然气 | 152篇 |
武器工业 | 65篇 |
无线电 | 1624篇 |
一般工业技术 | 275篇 |
冶金工业 | 449篇 |
原子能技术 | 14篇 |
自动化技术 | 2862篇 |
出版年
2024年 | 26篇 |
2023年 | 92篇 |
2022年 | 181篇 |
2021年 | 300篇 |
2020年 | 345篇 |
2019年 | 179篇 |
2018年 | 189篇 |
2017年 | 264篇 |
2016年 | 304篇 |
2015年 | 363篇 |
2014年 | 704篇 |
2013年 | 578篇 |
2012年 | 795篇 |
2011年 | 776篇 |
2010年 | 584篇 |
2009年 | 572篇 |
2008年 | 553篇 |
2007年 | 616篇 |
2006年 | 557篇 |
2005年 | 590篇 |
2004年 | 460篇 |
2003年 | 434篇 |
2002年 | 378篇 |
2001年 | 322篇 |
2000年 | 294篇 |
1999年 | 206篇 |
1998年 | 115篇 |
1997年 | 96篇 |
1996年 | 99篇 |
1995年 | 76篇 |
1994年 | 43篇 |
1993年 | 45篇 |
1992年 | 29篇 |
1991年 | 21篇 |
1990年 | 11篇 |
1989年 | 16篇 |
1988年 | 13篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1962年 | 1篇 |
1959年 | 2篇 |
1957年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
1.
Salehe Gomroki Zahra Yavari Ahmad Reza Abbasian Meissam Noroozifar 《International Journal of Applied Ceramic Technology》2021,18(6):2099-2110
The spongy nickel oxide (SNO) was synthesized the solution combustion method. The SNO was selected as a promoter to boost the catalytic activity of nanoraspberry-like palladium (NRPd) toward electrooxidation of five light fuels (LFs): methanol, ethanol, formaldehyde, formic acid, and ethylene glycol. The X-ray powder diffraction, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy, and field emission scanning electron microscope techniques were used for the materials characterization. In comparison with nonpromoted Pd, the NRPd-SNO electrocatalyst shown an excellent efficiency in parameters like the electrochemical active surface area and anti-CO poisoning behavior. The turnover data and the parameters, including reaction order, activation energy, and the coefficients of electron transfer and diffusion, were evaluated for the each process of LFs electrooxidation. The outcome for NRPd-SNO activity toward LFs electrooxidation was compared to some reported electrodes. The SNO increases the removal of intermediates created in the oxidation of LFs that can poison the surface of palladium catalyst. This is due to the presence of the lattice oxygens in SNO structure and Ni switching between its high and low valances. The compatibility of the adsorption process of LFs on the surface of the NRPd-SNO catalyst with different isotherms was determined by studying the Tafel polarization and calculating the surface coverage. 相似文献
2.
现阶段的语义解析方法大部分都基于组合语义,这类方法的核心就是词典。词典是词汇的集合,词汇定义了自然语言句子中词语到知识库本体中谓词的映射。语义解析一直面临着词典中词汇覆盖度不够的问题。针对此问题,该文在现有工作的基础上,提出了基于桥连接的词典学习方法,该方法能够在训练中自动引入新的词汇并加以学习,为了进一步提高新学习到的词汇的准确度,该文设计了新的词语—二元谓词的特征模板,并使用基于投票机制的核心词典获取方法。该文在两个公开数据集(WebQuestions和Free917)上进行了对比实验,实验结果表明,该文方法能够学习到新的词汇,提高词汇的覆盖度,进而提升语义解析系统的性能,特别是召回率。 相似文献
3.
P. Carrasqueira H. Rocha J. M. Dias T. Ventura B. C. Ferreira M. C. Lopes 《International Transactions in Operational Research》2023,30(1):206-223
Radiation therapy is a technology-driven cancer treatment modality that has experienced significant advances over the last decades, due to multidisciplinary contributions that include engineering and computing. Recent technological developments allow the use of noncoplanar volumetric modulated arc therapy (VMAT), one of the most recent photon treatment techniques, in clinical practice. In this work, an automated noncoplanar arc trajectory optimization framework designed in two modular phases is presented. First, a noncoplanar beam angle optimization algorithm is used to obtain a set of noncoplanar irradiation directions. Then, anchored in these directions, an optimization strategy is proposed to compute an optimal arc trajectory. The computational experiments considered a pool of twelve difficult head-and-neck tumor cases. It was possible to observe that, for some of these cases, the optimized noncoplanar arc trajectories led to significant treatment planning quality improvements, when compared with coplanar VMAT treatment plans. Although these experiments were done in a research environment treatment planning software (matRad), the conclusions can be of interest for a clinical setting: automated procedures can simplify the current treatment workflow, produce high-quality treatment plans, making better use of human resources and allowing for unbiased comparisons between different treatment techniques. 相似文献
4.
Highly accurate real‐time localization is of fundamental importance for the safety and efficiency of planetary rovers exploring the surface of Mars. Mars rover operations rely on vision‐based systems to avoid hazards as well as plan safe routes. However, vision‐based systems operate on the assumption that sufficient visual texture is visible in the scene. This poses a challenge for vision‐based navigation on Mars where regions lacking visual texture are prevalent. To overcome this, we make use of the ability of the rover to actively steer the visual sensor to improve fault tolerance and maximize the perception performance. This paper answers the question of where and when to look by presenting a method for predicting the sensor trajectory that maximizes the localization performance of the rover. This is accomplished by an online assessment of possible trajectories using synthetic, future camera views created from previous observations of the scene. The proposed trajectories are quantified and chosen based on the expected localization performance. In this study, we validate the proposed method in field experiments at the Jet Propulsion Laboratory (JPL) Mars Yard. Furthermore, multiple performance metrics are identified and evaluated for reducing the overall runtime of the algorithm. We show how actively steering the perception system increases the localization accuracy compared with traditional fixed‐sensor configurations. 相似文献
5.
中国大陆PCB产业自动化的现况与未来 总被引:1,自引:1,他引:0
从中国大陆PCB发展的现况分析实行设备自动化连线为企业所创造的价值。设备自动化连线是中国大陆PCB必须面临的改革出路。 相似文献
6.
广州蓄能水电厂运行与管理的现代化 总被引:7,自引:7,他引:0
黄国祯 《水电自动化与大坝监测》2002,26(1):14-17
介绍了广州蓄能水电厂的基本情况,其借鉴国外电站管理的先进经验,从设备在线监控 到运行、检修、生产管 理和办公均全面应用以计算机为核心的自动化系统及计算机网络技术,为提高机组安全可靠 运行、电站的管理水平和减人增效方面发挥了很好作用。文中着重介绍广州蓄能水电厂的运 行管理方式及值班规则、生产管理和设备管理方法、办公自动化经验以及相关的规章制度。 相似文献
7.
8.
9.
以葛洲坝水力发电厂主要自动化技术应用与设备改造为线索,重点回顾 了该厂实现计算机实时监控、全面提高综合自动化水平的历程;全面总结了该厂为实现“无 人值班”(少人值守)而进行的自动化设备换型改造情况和自动化新技术的应用情况;简要 阐述了自动化技术应用给该厂在运行和管理方面带来的深刻变化;展望了该厂未来自动化技 术应用的前景。 相似文献
10.