全文获取类型
收费全文 | 2147篇 |
免费 | 109篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 27篇 |
综合类 | 2篇 |
化学工业 | 601篇 |
金属工艺 | 92篇 |
机械仪表 | 41篇 |
建筑科学 | 39篇 |
能源动力 | 132篇 |
轻工业 | 152篇 |
水利工程 | 18篇 |
石油天然气 | 8篇 |
无线电 | 235篇 |
一般工业技术 | 522篇 |
冶金工业 | 167篇 |
原子能技术 | 18篇 |
自动化技术 | 214篇 |
出版年
2024年 | 8篇 |
2023年 | 62篇 |
2022年 | 99篇 |
2021年 | 122篇 |
2020年 | 74篇 |
2019年 | 89篇 |
2018年 | 111篇 |
2017年 | 94篇 |
2016年 | 104篇 |
2015年 | 72篇 |
2014年 | 85篇 |
2013年 | 182篇 |
2012年 | 98篇 |
2011年 | 123篇 |
2010年 | 85篇 |
2009年 | 76篇 |
2008年 | 85篇 |
2007年 | 69篇 |
2006年 | 59篇 |
2005年 | 41篇 |
2004年 | 43篇 |
2003年 | 30篇 |
2002年 | 30篇 |
2001年 | 21篇 |
2000年 | 27篇 |
1999年 | 19篇 |
1998年 | 48篇 |
1997年 | 31篇 |
1996年 | 33篇 |
1995年 | 17篇 |
1994年 | 19篇 |
1993年 | 17篇 |
1992年 | 9篇 |
1991年 | 16篇 |
1990年 | 14篇 |
1989年 | 18篇 |
1988年 | 13篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1976年 | 7篇 |
1975年 | 8篇 |
1973年 | 5篇 |
1970年 | 4篇 |
排序方式: 共有2268条查询结果,搜索用时 15 毫秒
1.
Wireless Personal Communications - Recently, the theory of effective rate has attracted much attention, since it can take the delay aspect into account when performing channel capacity analysis. In... 相似文献
2.
Wireless Personal Communications - In recent years, the emergence of Internet of things and cyber-physical system provide a proactive and efficacious solution to enable remote monitoring, machine... 相似文献
3.
4.
Jain Amita Yadav Sudesh Vij Sonakshi Kumar Yogesh Tayal Devendra Kumar 《Wireless Personal Communications》2020,110(3):1303-1321
Wireless Personal Communications - Traffic network is basically a “network of networks” consisting of mainly two types of networks: road network and a travel network. Due to drastic... 相似文献
5.
6.
Multimedia Tools and Applications - In the way of communication, facial expression act as non-verbal communication and play an important role in social interaction by providing some contextual... 相似文献
7.
8.
Ramanujam J. Jinpyo Hong Kandemir M. Narayan A. Agarwal A. 《Signal Processing, IEEE Transactions on》2006,54(1):286-294
Most embedded systems have limited amount of memory. In contrast, the memory requirements of the digital signal processing (DSP) and video processing codes (in nested loops, in particular) running on embedded systems is significant. This paper addresses the problem of estimating and reducing the amount of memory needed for transfers of data in embedded systems. First, the problem of estimating the region associated with a statement or the set of elements referenced by a statement during the execution of nested loops is analyzed. For a fixed execution ordering, a quantitative analysis of the number of elements referenced is presented; exact expressions for uniformly generated references and a close upper and lower bound for nonuniformly generated references are derived. Second, in addition to presenting an algorithm that computes the total memory required, this paper also discusses the effect of transformations (that change the execution ordering) on the lifetimes of array variables, i.e., the time between the first and last accesses to a given array location. The term maximum window size is introduced, and quantitative expressions are derived to compute the maximum window size. A detailed analysis of the effect of unimodular transformations on data locality, including the calculation of the maximum window size, is presented. 相似文献
9.
The reliability of a system is the probability that the system will perform its intended mission under given conditions. This
paper provides an overview of the approaches to reliability modelling and identifies their strengths and weaknesses. The models
discussed include structure models, simple stochastic models and decomposable stochastic models. Ignoring time-dependence,
structure models give reliability as a function of the topological structure of the system. Simple stochastic models make
direct use of the properties of underlying stochastic processes, while decomposable models consider more complex systems and
analyse them through subsystems. Petri nets and dataflow graphs facilitate the analysis of complex systems by providing a
convenient framework for reliability analysis. 相似文献
10.
Higher order elastic constants have been calculated in ZnS at 300 K and 500 K following the interaction potential model. Ultrasonic attenuation, velocity and other related parameters have been calculated using the higher order elastic constants for the different size of the material at 500 K. The size dependency of the ultrasonic properties is discussed in correlation with elastic, thermal and electrical properties. It has been found that the thermal conductivity is the main contributor to the behaviour of the ultrasonic attenuation as a function of the size and the responsible cause of attenuation is phonon-phonon interaction. The semiconducting nature of ZnS film has been achieved with the study of size variation of thermal relaxation time and ultrasonic attenuation. 相似文献