| 151. |
- You, Qiangwei, et al.
(författare)
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Microstructure and properties of porous SiC ceramics by LPCVI technique regulation
- 2017
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Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 43:15, s. 11855-11863
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Tidskriftsartikel (refereegranskat)abstract
- A new gradient pore structure in porous SiC ceramics was fabricated by low pressure chemical vapor infiltration (LPCVI). Effects of deposition duration on the mechanical properties and permeability of porous SiC ceramics were investigated. Results demonstrated that pore diameter and shapes decreased from the surface to the interior along with LPCVI duration. Porous SiC ceramics with deposition duration of 160 h exhibited flexural strength of 48.05 MPa and fracture toughness of 1.30 MPa m(1/2), where 221% and 189% improvements were obtained compared to porous SiC ceramics without LPCVI, due to CVI-SiC layer strengthening effect. Additionally, at the same gas velocity, pressure drop increase rate was faster due to apparent porosity and pore size change.
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| 152. |
- Yu, Sheng-Xiang, et al.
(författare)
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Phylogeny of Impatiens (Balsaminaceae) : integrating molecular and morphological evidence into a new classification
- 2016
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Ingår i: Cladistics. - : Wiley-Blackwell. - 0748-3007 .- 1096-0031. ; 32:2, s. 179-197
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Tidskriftsartikel (refereegranskat)abstract
- Impatiens L. is one of the largest angiosperm genera, containing over 1000 species, and is notorious for its taxonomic difficulty. Here, we present, to our knowledge, the most comprehensive phylogenetic analysis of the genus to date based on a total evidence approach. Forty-six morphological characters, mainly obtained from our own investigations, are combined with sequence data from three genetic regions, including nuclear ribosomal ITS and plastid atpB-rbcL and trnL-F. We include 150 Impatiens species representing all clades recovered by previous phylogenetic analyses as well as three outgroups. Maximum-parsimony and Bayesian inference methods were used to infer phylogenetic relationships. Our analyses concur with previous studies, but in most cases provide stronger support. Impatiens splits into two major clades. For the first time, we report that species with three-colpate pollen and four carpels form a monophyletic group (clade I). Within clade II, seven well-supported subclades are recognized. Within this phylogenetic framework, character evolution is reconstructed, and diagnostic morphological characters for different clades and subclades are identified and discussed. Based on both morphological and molecular evidence, a new classification outline is presented, in which Impatiens is divided into two subgenera, subgen. Clavicarpa and subgen. Impatiens; the latter is further subdivided into seven sections.
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| 153. |
- Yuan, Bo, et al.
(författare)
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Fabrication and microstructure of porous SiC ceramics with Al2O3 and CeO2 as sintering additives
- 2016
-
Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 42:11, s. 12613-12616
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, porous silicon carbide ceramics were prepared via spark plasma sintering at relatively low temperatures using Al2O3 and CeO2 as sintering additives. Sacrificial template was selected as the pore forming mechanism, and gelcasting was used to fix the slurry in a short time. The evolution process of the microstructures during different steps was observed by SEM. The influence of the sintering temperature and sintering additives on the shrinkage and porosity of the samples was studied. The microstructures of different samples were characterized, and the mechanical properties were also evaluated.
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| 154. |
- Yuan, Bo, et al.
(författare)
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Preparation and properties of porous silicon carbide based ceramic filter
- 2016
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 684, s. 613-615
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Tidskriftsartikel (refereegranskat)abstract
- Porous silicon carbide ceramics with high open porosity and large pore size are usually applied as filters for the cleaning of hot dust gases. However, the large porosity and large pore size will decrease the mechanical properties. In the present study, porous SiC ceramics were prepared using bentonite as bonding phase. The effects of sintering temperature on the microstructure and the compressive strength were studied. Bentonite could melt and spread on the surface of silicon carbide particles at all the sintering temperatures. However, the bonding effects were very different at different temperatures.
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| 155. |
- Zeng, Xuezhi, et al.
(författare)
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Silver Ink Patch Antenna for Passive RFID
- 2007
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Ingår i: Proceedings of ISAP2007, Niigata, Japan. - : IEEE conference proceedings. - 9784885522239 ; , s. 612-615
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Konferensbidrag (refereegranskat)
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| 156. |
- Zeng, Xuezhi, et al.
(författare)
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Slots in Metallic Label as RFID Tag Antenna
- 2007
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Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - New York : IEEE conference proceedings. - 9781424408771 ; , s. 1600-1603
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Konferensbidrag (refereegranskat)
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| 157. |
- Zhang, Dan, et al.
(författare)
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A survey on attack detection, estimation and control of industrial cyber-physical systems
- 2021
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Ingår i: ISA transactions. - : Elsevier. - 0019-0578 .- 1879-2022. ; 116, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- Cyber-physical systems (CPSs) are complex systems that involve technologies such as control, communication, and computing. Nowadays, CPSs have a wide range of applications in smart cities, smart grids, smart manufacturing and intelligent transportation. However, with integration of industrial control systems with modern communication technologies, CPSs would be inevitably exposed to increasing security threats, which could lead to severe degradation of the system performance and even destruction of CPSs. This paper presents a survey on recent advances on security issues of industrial cyber-physical systems (ICPSs). We specifically discuss two typical kinds of attacks, i.e., Denial-of-Service (DoS) attack and Deception attack, and present recent results in terms of attack detection, estimation, and control of ICPSs. Classifications of current studies are analyzed and summarized based on different system modeling and analysis methods. In addition, advantages and disadvantage of various methodologies are also discussed. Finally, the paper concludes with some potential future research directions on secure ICPSs.
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| 158. |
- Zhang, Lin, et al.
(författare)
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Decentralized Caching Schemes and Performance Limits in Two-Layer Networks
- 2018
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Ingår i: IEEE Transactions on Vehicular Technology. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0018-9545 .- 1939-9359. ; 67:12, s. 12177-12192
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Tidskriftsartikel (refereegranskat)abstract
- We study the decentralized caching scheme in a two-layer network, which includes a server, multiple helpers, and multiple users. Basically, the proposed caching scheme consists of two phases, i.e., placement phase and delivery phase. In the placement phase, each helper/user randomly and independently selects contents from the server and stores them into its memory. In the delivery phase, the users request contents from the server, and the server satisfies each user through a helper. Different from the existing caching scheme, the proposed caching scheme takes into account the pre- stored contents at both helpers and users in the placement phase to design the delivery phase. Meanwhile, the proposed caching scheme exploits index coding in the delivery phase and leverages multicast opportunities, even when different users request distinct contents. Besides, we analytically characterize the performance limit of the proposed caching scheme, and show that the achievable rate region of the proposed caching scheme lies within constant margins to the information-theoretic optimum. In particular, the multiplicative and additive factors are carefully sharpened to be 1/48 and 4, respectively, both of which are better than the state of arts. Finally, simulation results demonstrate the advantage of the proposed caching scheme compared with the state of arts.
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| 159. |
- Zhang, Lin, et al.
(författare)
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Order-Optimal Caching in Hierarchical Networks
- 2016
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Ingår i: 2016 IEEE/CIC INTERNATIONAL CONFERENCE ON COMMUNICATIONS IN CHINA (ICCC). - : IEEE.
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Konferensbidrag (refereegranskat)abstract
- The decentralized caching is studied in hierarchical networks, where users request contents through intermediate nodes (helpers) from a file server. By placing contents randomly and independently in each node and carefully designing the data delivery, the correlations of the pre-stored contents across layers can be utilized to reduce the transmission rate in each layer. A hybrid caching scheme is developed by exploiting the cross-layer storage correlations as well as the single-layer and cross-layer multicast opportunities. It is observed that the achievable rate region of the hybrid caching scheme is strictly better than the caching scheme in [1]. Furthermore, the order-optimality of the hybrid caching scheme is demonstrated by achieving the performance within constant multiplicative and additive factors of the information-theoretic optimum. In particular, the multiplicative and additive factors are carefully quantified to be 1/48 and 4, respectively.
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| 160. |
- Zhang, Ruiying, et al.
(författare)
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Comparative phylogeography of two widespread magpies : importance of habitat preference and breeding behavior on genetic structure in China.
- 2012
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 65:2, s. 562-72
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Tidskriftsartikel (refereegranskat)abstract
- Historical geological events and climatic changes are believed to have played important roles in shaping the current distribution of species. However, sympatric species may have responded in different ways to such climatic fluctuations. Here we compared genetic structures of two corvid species, the Azure-winged Magpie Cyanopica cyanus and the Eurasian Magpie Pica pica, both widespread but with different habitat dependence and some aspects of breeding behavior. Three mitochondrial genes and two nuclear introns were used to examine their co-distributed populations in East China and the Iberian Peninsula. Both species showed deep divergences between these two regions that were dated to the late Pliocene/early Pleistocene. In the East Chinese clade of C. cyanus, populations were subdivided between Northeast China and Central China, probably since the early to mid-Pleistocene, and the Central subclade showed a significant pattern of isolation by distance. In contrast, no genetic structure was found in the East China populations of P. pica. We suggest that the different patterns in the two species are at least partly explained by ecological differences between them, especially in habitat preference and perhaps also breeding behavior. These dissimilarities in life history traits might have affected the dispersal and survival abilities of these two species differently during environmental fluctuations.
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