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Peroformance analysis of decode-and-forward MIMO relay channels with OSTBCs

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The Journal of China Universities of Posts and Telecommunications 2011年第1期18卷 16-22页

作者： HU chun-jing CHEN Shu-ping WANG Wen-bo ZHAO dong Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China Wireless Network Technology Department China Telecom Beijing Research Institute Beijing 100035 China

Performance analysis is presented for multiple-input multiple-output （MIMO） relay channels employing transmit antenna diversity with orthogonal space-time block codes （OSTBCs）, where the source and the destination are equipped with Ns and Nd antennas, and communicate with each other with the help of a multiple-antenna relay operating in decode-and-forward （DF） mode Over independent, not necessarily identical Rayleigh fading channels, exact closed-form symbol error rate （SER） expressions are derived for various digital modulation formats for both the OSTBC transmission with and without the direct link, The moment generating functions （MGFs） for overall system signal-noise ratios （SNRs） are also derived, based on which we present a unified SER analysis. The analysis shows that full spatial diversity order can be achieved for the DF M1MO relay channel by adopting OSTBC transmissions and maximal ratio combining （MRC） receptions. All the analytical results are confirmed through comparison with the results obtained using Mento Carlo simulations.

关键词： relay system MIMO OSTBC symbol error rate (SER)

A Study of the Gas Flow through Air Jet Loom

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Journal of Thermal Science 2007年第2期16卷 159-163页

作者： Heuy-dong Kim Chae-Min Lim Ho-Joon Lee Doo-Hwan chun School of Mechanical Engineering Andong National University388Songcheon-dongAndong 760-749KoreaE-mail:kimhd Korea Textile Machinery Research Institute 300Sampoong-dongKyeongsan 712-210Korea

Air jet loom, as one of the shuttleless looms, transports a yam into warps using viscosity and kinetic energy of an air jet. Performance of this picking system depends on the ability of instantaneous inhalation/exhaust, configuration of nozzle, operation characteristics of a check valve, etc. In the recent past, many studies have been reported on the air jet discharged from a nozzle exit, but studies for understanding the flow field characteristics associated with shear layer and shock wave/boundary layer interaction in the nozzle were not conducted enough. In this paper, a computational study was performed to explain the flow field in the air jet nozzle with an acceleration tube and validated with previous experimental data available. The results obtained from the computational study show that, in the supersonic flow regime, the flow field depends significantly on the length of acceleration tube. As nozzle pressure ratio increases, drag force acting on the string also increases. For a longer acceleration tube, the total pressure loss is large, owing to the frictional loss.

关键词： compressible flow nozzle shear layer shock wave air jet loom shuttleless loom

Formation and corrosion properties of Fe-based bulk metallic glasses

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 323-326页

作者： chun-lei Zhu Qing Wang Jie Zhang Ying-min Wang Chuang dong School of Material Science and Engineering Dalian University of Technology Dalian 116024 China

Bulk metallic glass （BMG） formation was explored in the Fe-B-Si-Nb alloy system though combined use of the atomic cluster line approach and the minor alloying strategy. The basic ternary compositions in the Fe-B-Si system were determined by the intersection points of two cluster lines, namely, Fe-B cluster to Si and Fe-Si cluster to B. 3at% -4at% Nb was added to the quaternary Fe-B-Si-Nb alloy. The casting experiments revealed that good glass-forming ability （GFA） occurred at the （Fe73.4Si8.2B18.4）96Nb4 composition, and 3-mm diameter BMG samples were made. The glass transition temperature （Tg）, crystallization temperature （Tx）, and supercooled liquid region （△Tx=Tx-Tg） of this BMG were measured to be 866, 889, and 23 K, respectively. The BMG shows a high Vickers hardness of about Hv 1164, a Young＇s modulus of 180 GPa, and a good corrosion resistance in the solutions of 1 mol/L HCl and 3wt% NaCl.

关键词： bulk metallic glasses (BMG) cluster atomic cluster corrosion glass-forming ability

Effect of chemical reactivity on the detonation initiation in shock accelerated flow in a confined space

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Acta Mechanica Sinica 2013年第1期29卷 54-61页

作者： Yue-Jin Zhu Gang dong Yi-Xin Liu Bao-chun Fan Hua Jiang State Key Laboratory of Transient Physics Nanjing University of Science and Technology State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

The interactions of a spherical flame with an incident shock wave and its reflected shock wave in a confined space were investigated using the three-dimensional reactive Navier-Stokes equations, with emphasis placed on the effect of chemical reactivity of mixture on the flame distortion and detonation initiation after the passage of the reflected shock wave. It is shown that the spatio-temporal characteristics of detonation initiation depend highly on the chemi- cal reactivity of the mixture. When the chemical reactivity enhances, the flame can be severely distorted to form a reactive shock bifurcation structure with detonations initiating at different three-dimensional spatial locations. Moreover, the detonation initiation would occur earlier in a mixture of more enhanced reactivity. The results reveal that the detona- tions arise from hot spots in the unburned region which are initiated by the shock-detonation-transition mechanism.

关键词： Chemical reactivity Reactive shock bifurcation structure ~ Detonation initiation Hot spot Shock wave

Influencing factors of sediment deposition and their spatial variability in riparian zone of the Three Gorges Reservoir,China

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Journal of Mountain Science 2016年第8期13卷 1387-1396页

作者： WANG Bin-yan YAN dong-chun WEN An-bang CHEN Jia-cun Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China

Many factors can affect the sediment deposition and soil erosion process in riparian zone, including terrain, sediment transport and water level fluctuations. Clarifying the factors influencing sediment deposition process in the riparian zone of the Three Gorges Reservoirs is an important problem to determine the key area of sediment deposition and its trend of development in the study area. In order to reveal the influence of these environmental factors on the sediment deposition in riparian zone of the Three Gorges Reservoir, this study investigated 1） the amount of deposited sediment in different environmental conditions, 2） the potential factors affecting sediment deposition in riparian zone of the Three Gorges Reservoir, 3） the relationship between the deposited sediment amount and these factors previously mentioned using correlation analysis, and 4） the influence of human activities considered as an additional factor. This study found that 1） slope gradient, elevation, inundating duration and human activities were the main factors influencing sedimentation in riparian zone of the Three Gorges Reservoir, and 2） the impact of each factor varied with spaces. Specifically, in the upper reach from Jiangjin to Fuling, human activities such as gravel dredging, bank revetment and ports and wharfs constructing disturbed considerable amounts of deposited sediment, as a result, there was no natural law to dictate the distribution. In the middle reach from Fuling to Fengjie, slope gradient and inundating duration were the controlling factors, and the sediment deposition amount was greater in the areas with a gentler slope or lower elevation. Water flow on gentler slopes generally had lower velocity, resulting in more sediment to deposit. Sites with lower elevations would be drowned by sediment-laden flow with a longer duration resulting from hydrologic regime controlled by the operating strategy of the Three Gorges Reservoir, leading to a larger amount of sediment deposit

关键词： Influencing Factors Spatial variability Sediment deposition Riparian zone Three GorgesReservoir

Hardy spaces H^p over non-homogeneous metric measure spaces and their applications

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Science China Mathematics 2015年第2期58卷 309-388页

作者： FU Xing LIN Hai Bo YANG Da chun YANG dong Yong School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex SystemsMinistry of Education College of Science China Agricultural University School of Mathematical Sciences Xiamen University

Let(X,d,)be a metric measure space satisfying both the geometrically doubling and the upper doubling *** ρ∈(1,∞),0 详细信息

Let(X,d,)be a metric measure space satisfying both the geometrically doubling and the upper doubling *** ρ∈(1,∞),0

关键词： non-homogeneous metric measure space ρ-weakly doubling measure Hardy space Campanato space Lipschitz space Calder′on-Zygmund operator atomic block molecular block

Incomplete radiofrequency ablation promotes the development of CD133+cancer stem cells in hepatocellular carcinoma cell line HepG2 via inducing SOX9 expression

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Hepatobiliary & Pancreatic Diseases International 2018年第5期17卷 416-422页

作者： chun-Wang Yuan Zhen-Chang Wang Kai Liu dong-Jie Liu Department of Radiology Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Center of Interventional Oncology and Liver Diseases Beijing Youan HospitalCapital Medical UniversityBeijing 100069China Beijing Institute of Hepatology Beijing 100069China Beijing Precision Medicine and Transformation Engineering Technology Research Center of Hepatitis and Liver Cancer Beijing 100069China Department of Biochemistry and Molecular Biology Baotou Medical CollegeBaotou 014040China

Background: Cancer stem cells(CSCs) accelerate the growth of hepatocellular carcinoma(HCC) residual after incomplete radiofrequency ablation(In-RFA). The present study aimed to detect the effects of In-RFA on stemness transcription factors(STFs) expression which are important for the production and function of CSCs, and to find which STFs promote HCC stemness after In-RFA. Methods: HepG2 cells were used for in vitro and in vivo studies. Flow cytometry and sphere-formation assays were used to detect the level and function of CD133~+ CSCs in the models. PCR array and ELISA were applied to analyze the altered expression of 84 STFs in CD133~+ CSCs in two models. Specific lentiviral shRNA was used to knockdown STFs expression, followed by detecting In-RFA’s effects on the levels and function of CD133~+ CSCs. Results: In-RFA was identified to induce CD133~+ CSCs and increase their tumorigenesis ability in vitro and in vivo. The mRNA levels of 84 STFs in CD133~+ CSCs were detected by PCR array, showing that 15 and 22 STFs were up-regulated in two models, respectively. Meanwhile, the mRNA levels of seven common STFs were up-regulated in both models. ELISA assay demonstrated that only the protein of sex determining region Y-box 9(SOX9) was up-regulated in both models, the protein levels of the other 6 common STFs did not increase in both models. Finally, SOX9 was identified to play an important role in inducing, maintaining stemness and promoting tumorigenesis ability of CD133~+ CSCs in both models. Conclusion: In-RFA-induced SOX9 stimulates CD133~+ CSCs proliferation and increases their tumorigenesis ability, suggesting that SOX9 may be a good target for HCC treatment.

关键词： Hepatocellular carcinoma Radiofrequency ablation HepG2 Cancer stem cells

Phenylalanine ammonia-lyase gene families in cucurbit species: Structure, evolution, and expression

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Journal of Integrative Agriculture 2016年第6期15卷 1239-1255页

作者： dong chun-juan CAO Ning ZHANG Zhi-gang SHANG Qing-mao Institute of Vegetables and Flowers Chinese Academy of Agricultural SciencesKey Laboratory of Horticultural Crop Biology and Germplasm Innovation Ministry of Agriculture

Phenylalanine ammonia-lyase （PAL）, the first enzyme of phenylpropanoid pathway, is always encoded by multigene families in plants. In this study, using genome-wide searches, 13 PAL genes in cucumber （CsPAL1-13） and 13 PALs in melon （Cm- PALl-13） were identified. In the corresponding genomes, ten of these PAL genes were located in tandem in two clusters, while the others were widely dispersed in different chromosomes as a single copy. The protein sequences of CsPALs and CmPALs shared an overall high identity to each other. In our previous report, 12 PAL genes were identified in watermelon （CIPAL1-12）. Thereby, a total of 38 cucurbit PAL members were included. Here, a comprehensive comparison of PAL gene families was performed among three cucurbit plants. The phylogenetic and syntenic analyses placed the cucurbit PALs as 11 CsPAL-CmPAL-CIPAL triples, of which ten triples were clustered into the dicot group, and the remaining one, CsPAL1-CmPAL8-CIPAL2, was grouped with gymnosperm PALs and might serve as an ancestor of cucurbit PALs. By comparing the syntenic relationships and gene structure of these PAL genes, the expansion of cucurbit PAL families might arise from a series of segmental and tandem duplications and intron insertion events. Furthermore, the expression profiling in different tissues suggested that different cucurbit PALs displayed divergent but overlapping expression profiles, and the CsPAL-CmPAL-CIPAL orthologs showed correlative expression patterns among three cucurbit plants. Taken together, this study provided an extensive description on the evolution and expression of cucurbit PAL gene families and might facilitate the further studies for elucidating the functions of PALs in cucurbit plants.

关键词： phenylalanine ammonia-lyase (PAL) gene family cucurbit evolution expression

Surface Nanocrystallization of Nb-Ti Stabilized 439M Ferritic Stainless Steel

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Journal of Iron and Steel Research International 2014年第9期21卷 891-896页

作者： Yao-chun ZHANG Chao CHEN Cheng-jia SHANG dong-yang LI Nuclear Equipment Division CNNC China Nuclear Power Engineering Co.Ltd. School of Materials Science and Engineering University of Science and Technology Beijing Department of Chemical and Materials Engineering University of AlbertaEdmonton T6G2V4AlbertaCanada

A new nanocrystallization process was designed, which included punching the surface coating to generate dislocation network or cells and recovery treatment to turn the dislocation cells into nano-sized grains. The effort was made to increase the service life of Nb-Ti stabilized 439M stainless steel surface with medium passive ability, particularly to enhance the outmost surface layer by nanocrystallization for improving resistances to corrosion. Electrochemical properties, electron work functions （EWFs）, nano-mechanical properties of the nanocrystallized surfaces were investigated. It was demonstrated that the nanocrystallized 439M stainless steel surface exhibited improved resistance to corrosion in 0.5 mol/L H2 SO4 solution. However, the nanoci＇ystallized 439M stainless steel surface exhibited decreased resistance to corrosion in 3.5% NaCl solution.

关键词： nanocrystallization corrosion ferritic stainless steel punching recovery