全文获取类型
收费全文 | 159篇 |
免费 | 8篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 22篇 |
金属工艺 | 3篇 |
建筑科学 | 2篇 |
能源动力 | 5篇 |
轻工业 | 7篇 |
水利工程 | 7篇 |
无线电 | 33篇 |
一般工业技术 | 16篇 |
冶金工业 | 1篇 |
自动化技术 | 69篇 |
出版年
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 11篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 7篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
排序方式: 共有167条查询结果,搜索用时 0 毫秒
161.
162.
Vasileios Theodorakopoulos Michael E. Woodward 《Multimedia Tools and Applications》2006,28(2):125-139
This paper presents a unique set of techniques to support reliable and efficient video transmission over mobile channels.
The transmission system is comprised of an M level Quadrature Amplitude Modulation (QAM) technique. A twin class uniform and non-uniform partitioned M-QAM system is used
to transport a compressed video bitstream which is partitioned to match the bit-error sensitivity of the transmitted symbol
in terms of mapping in the constellation diagram and picture quality. Video partitioning based on a separation of the Variable
Length Coded (VLC) Discrete Cosine Transforms (DCT) coefficients within each block is considered for constant bitrate transmission
(CBR). Various scenarios for splitting the bitstream are investigated and their results are compared and analysed thoroughly.
The performance of the transmission system is evaluated under Additive White Gaussian Noise (AWGN) conditions. The simulation
results showed that the video partition strategy results in a significantly higher quality of the reconstructed video data. 相似文献
163.
164.
Vasileios Alevizakos Christos Koukouvinos 《Quality and Reliability Engineering International》2020,36(2):675-704
Zero-inflated Poisson (ZIP) model is very useful in high-yield processes where an excessive number of zero observations exist. This model can be viewed as an extension of the standard Poisson distribution. In this paper, a one-sided generally weighted moving average (GWMA) control chart is proposed for monitoring upward shifts in the two parameters of a ZIP process (regarded as ZIP-GWMA chart). The design parameters of the proposed chart are provided, and through a simulation study, it is shown that the ZIP-GWMA performs better than the existing control charts under shifts in both parameters. Moreover, an illustrative example is presented to display the application of the proposed chart on practitioners. 相似文献
165.
Antonios Alexiou Christos Bouras Vasileios Kokkinos 《Wireless Personal Communications》2011,61(2):447-464
In mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance. To this
end, Multimedia Broadcast/Multicast Service (MBMS)—that was introduced in the Release 6 of Universal Mobile Telecommunication
System (UMTS)—is envisaged to play an instrumental role in the proliferation of mobile market. The reason behind the design
of MBMS was the need to provide multiple users with the same data at the same time in 3GPP (3rd Generation Partnership Project)
cellular networks. Still, MBMS performance is limited by the base stations’ transmission power. As an aftermath, efficient
power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile
users. This paper proposes a novel mechanism for efficient radio bearer selection during MBMS transmissions. The proposed
mechanism is based on the concept of transport channels combination in any cell of the network. Furthermore, the mechanism
exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas and manages to efficiently
deliver multiple MBMS sessions. The proposed mechanism is thoroughly evaluated and compared with the radio bearer selection
mechanisms proposed by 3GPP. 相似文献
166.
Velimir Mladenov Vasileios Fotopoulos Eirini Kaiserli Erna Karalija Stephane Maury Miroslav Baranek Naama Segal Pilar S. Testillano Valya Vassileva Glria Pinto Manuela Nagel Hans Hoenicka Dragana Miladinovi Philippe Gallusci Chiara Vergata Aliki Kapazoglou Eleni Abraham Eleni Tani Maria Gerakari Efi Sarri Evaggelia Avramidou Mateo Gaparovi Federico Martinelli 《International journal of molecular sciences》2021,22(13)
Although epigenetic modifications have been intensely investigated over the last decade due to their role in crop adaptation to rapid climate change, it is unclear which epigenetic changes are heritable and therefore transmitted to their progeny. The identification of epigenetic marks that are transmitted to the next generations is of primary importance for their use in breeding and for the development of new cultivars with a broad-spectrum of tolerance/resistance to abiotic and biotic stresses. In this review, we discuss general aspects of plant responses to environmental stresses and provide an overview of recent findings on the role of transgenerational epigenetic modifications in crops. In addition, we take the opportunity to describe the aims of EPI-CATCH, an international COST action consortium composed by researchers from 28 countries. The aim of this COST action launched in 2020 is: (1) to define standardized pipelines and methods used in the study of epigenetic mechanisms in plants, (2) update, share, and exchange findings in epigenetic responses to environmental stresses in plants, (3) develop new concepts and frontiers in plant epigenetics and epigenomics, (4) enhance dissemination, communication, and transfer of knowledge in plant epigenetics and epigenomics. 相似文献
167.
Vasileios Katranidis Sai Gu David C. Cox Mark J. Whiting Spyros Kamnis 《Journal of Thermal Spray Technology》2018,27(5):898-908
The thermal dissolution and decarburization of WC-based powders that occur in various spray processes are a widely studied phenomenon, and mechanisms that describe its development have been proposed. However, the exact formation mechanism of decarburization products such as metallic W is not yet established. A WC-17Co coating is sprayed intentionally at an exceedingly long spray distance to exaggerate the decarburization effects. Progressive xenon plasma ion milling of the examined surface has revealed microstructural features that would have been smeared away by conventional polishing. Serial sectioning provided insights on the three-dimensional structure of the decarburization products. Metallic W has been found to form a shell around small splats that did not deform significantly upon impact, suggesting that its crystallization occurs during the in-flight stage of the particles. W2C crystals are more prominent on WC faces that are in close proximity with splat boundaries indicating an accelerated decarburization in such sites. Porosity can be clearly categorized in imperfect intersplat contact and oxidation-generated gases via its shape. 相似文献