全文获取类型
收费全文 | 5023篇 |
免费 | 301篇 |
国内免费 | 319篇 |
专业分类
电工技术 | 179篇 |
技术理论 | 1篇 |
综合类 | 168篇 |
化学工业 | 172篇 |
金属工艺 | 106篇 |
机械仪表 | 391篇 |
建筑科学 | 297篇 |
矿业工程 | 72篇 |
能源动力 | 59篇 |
轻工业 | 316篇 |
水利工程 | 39篇 |
石油天然气 | 123篇 |
武器工业 | 24篇 |
无线电 | 667篇 |
一般工业技术 | 244篇 |
冶金工业 | 48篇 |
原子能技术 | 242篇 |
自动化技术 | 2495篇 |
出版年
2024年 | 14篇 |
2023年 | 42篇 |
2022年 | 79篇 |
2021年 | 114篇 |
2020年 | 131篇 |
2019年 | 73篇 |
2018年 | 91篇 |
2017年 | 129篇 |
2016年 | 149篇 |
2015年 | 172篇 |
2014年 | 356篇 |
2013年 | 275篇 |
2012年 | 360篇 |
2011年 | 450篇 |
2010年 | 340篇 |
2009年 | 281篇 |
2008年 | 313篇 |
2007年 | 384篇 |
2006年 | 340篇 |
2005年 | 286篇 |
2004年 | 214篇 |
2003年 | 224篇 |
2002年 | 130篇 |
2001年 | 105篇 |
2000年 | 119篇 |
1999年 | 93篇 |
1998年 | 65篇 |
1997年 | 66篇 |
1996年 | 55篇 |
1995年 | 36篇 |
1994年 | 26篇 |
1993年 | 25篇 |
1992年 | 27篇 |
1991年 | 19篇 |
1990年 | 19篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有5643条查询结果,搜索用时 15 毫秒
1.
《Ceramics International》2022,48(11):15462-15469
Due to its unique artistic value, mosaic ceramics are widely used in construction-related fields. To meet the artist's demand for high-quality mosaic ceramic to create artistic works, it is necessary to meet the needs for efficient screening of mosaic ceramic tiles. Different from the ordinary large-target ceramics, mosaic ceramics exhibit characteristics of small tile sizes, a variety of colors, large demand for quantities, and easy reflection on the surface. Common manual detection methods show problems of low efficiency or accuracy, easy to fatigue, and many others. To solve these problems, this paper proposes a new detection method to identify surface defects of mosaic ceramic tiles and designs a detection system platform to achieve rapid detection. The experiment proves that the detection system has a detection rate of 93.99% for small defects on the surface of mosaic ceramic tiles, and the detection time of a single mosaic ceramic tile is less than 0.06 s. The detection method can quickly and accurately screen out high-quality, defect-free mosaic ceramic tiles, which can effectively improve the quality and artistic value of mosaic ceramic art creation. 相似文献
2.
The effect of the emergency perception of bystanders of cyberbullying victims on helping behaviors is often neglected in research on cyberbullying. In this study, we explored the influence of this cognitive factor on cyber-bystanders’ helping tendencies as well as elucidated possible underlying processes. The results of two studies were reported. In Study 1, 150 undergraduates read a true case of a girl experiencing cyberbullying. The results indicated that when the participants perceived the victim’s situation to be more critical (i.e., higher emergency perception), their helping tendencies were stronger, partly through increased state empathy followed by feelings of responsibility to help. In Study 2, we randomly assigned 300 undergraduates to two groups. The low emergency group read the same cyberbullying case as Study 1, whereas the cyberbullying case read by the high emergency group contained additional emergency information of the victim. The results indicated that the high emergency group expressed stronger helping tendencies than did the low emergency group. This effect was caused by a stronger perception that the victim was in an emergency situation, which not only strengthened the participants’ helping tendencies directly but also indirectly through increasing their state empathy and feelings of responsibility to help. 相似文献
3.
4.
华治国 《混凝土与水泥制品》2020,(6):70-72
选择了几份典型的外墙外保温系统标准,通过对这几份标准中胶粘剂和抹面胶浆的成型和检测方法的比较,分析了现有检测技术的优劣,并结合工作实践提出了建议。 相似文献
5.
6.
为确保特殊时期党政军指挥通信畅通,充分利用中国移动现网资源,将卫星通信与地面光缆、微波传榆。以及移动网络无缝衔接,共同构建中国移动天地一体应急通信平台。 相似文献
7.
讨论了如何利用Access7.0设计包含有通信的管理信息系统,并结合生产管理系统的实例。利用微软公司的Visual Basic中包含的通信控件,实现Windows95环境下通信程序的设计方法,介绍了通信控件的属性以及使用方法,给出了基本的通信程序。 相似文献
8.
9.
Mining process models with non-free-choice constructs 总被引:6,自引:0,他引:6
Lijie Wen Wil M. P. van der Aalst Jianmin Wang Jiaguang Sun 《Data mining and knowledge discovery》2007,15(2):145-180
Process mining aims at extracting information from event logs to capture the business process as it is being executed. Process
mining is particularly useful in situations where events are recorded but there is no system enforcing people to work in a
particular way. Consider for example a hospital where the diagnosis and treatment activities are recorded in the hospital
information system, but where health-care professionals determine the “careflow.” Many process mining approaches have been
proposed in recent years. However, in spite of many researchers’ persistent efforts, there are still several challenging problems
to be solved. In this paper, we focus on mining non-free-choice constructs, i.e., situations where there is a mixture of choice
and synchronization. Although most real-life processes exhibit non-free-choice behavior, existing algorithms are unable to
adequately deal with such constructs. Using a Petri-net-based representation, we will show that there are two kinds of causal
dependencies between tasks, i.e., explicit and implicit ones. We propose an algorithm that is able to deal with both kinds
of dependencies. The algorithm has been implemented in the ProM framework and experimental results shows that the algorithm
indeed significantly improves existing process mining techniques. 相似文献
10.
Motion Perception Using Analog VLSI 总被引:2,自引:0,他引:2
Andre J.S. Yakovleff Alireza Moini 《Analog Integrated Circuits and Signal Processing》1998,15(2):183-200
Motion perception is arguably a fundamental mechanism used by natural species to accomplish a number of tasks, such as navigating freely in an unknown environment. Traditional motion perception methods tend to be computationally intensive, requiring powerful computers and large memories. However, by copying biological mechanisms, such as elementary motion discrimination at the early stages of the visual processing paths, it should be possible to build small and efficient motion perception systems. This paper describes the manner in which a simple motion perception model based on the insect visual system has been implemented using mixed analog/digital VLSI. The device has been fabricated in a 2 micron double metal, double polysilicon process, and comprises 61 photo-detectors, and associated analog and digital circuitry. While not entirely successful in that component mismatches hamper the detection of dark-to-bright changes in contrast, the results clearly show the feasibility of using such a device in autonomous control systems. 相似文献