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Time-Domain Higher-Order Boundary Element Method for Simulating High Forward-Speed Ship Motions in Waves

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China Ocean Engineering 2024年第5期38卷 904-914页

作者： ZHOU Xiao-guo CHENG yong PAN su-yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

The hydrodynamic performance of a high forward-speed ship in obliquely propagating waves is numerically examined to assess both free motions and wave field in comparison with a low forward-speed *** numerical model is based on the time-domain potential flow theory and higher-order boundary element method,where an analytical expression is completely expanded to determine the base-unsteady coupling flow imposed on the moving condition of the *** ship in the numerical model may possess different advancing speeds,***,low speed,and high *** role of the water depth,wave height,wave period,and incident wave angle is analyzed by means of the accurate numerical *** is found that the resonant motions of the high forward-speed ship are triggered by comparison with the stationary *** specifically,a higher forward speed generates a V-shaped wave region with a larger elevation,which induces stronger resonant motions corresponding to larger wave *** shoaling effect is adverse to the motion of the low-speed ship,but is beneficial to the resonant motion of the high-speed *** waves obliquely propagate toward the ship,the V-shaped wave region would be broken due to the coupling effect between roll and pitch *** is also demonstrated that the maximum heave motion occurs in beam seas for stationary cases but occurs in head waves for high ***,the variation of the pitch motion with period is hardly affected by wave incident angles.

关键词： high forward speed oblique incident waves ship motion higher-order boundary element method time domain wave field

Hydraulic experiment on mushroom head in bottom-blown smelting furnace

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Journal of Iron and Steel Research International 2017年第5期24卷 490-494页

作者： Fu-yong su Zhi Wen School of Energy and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China

There are many bottom-blown smelting furnaces in metallurgical industry. When oxygen or air sprays from the jet nozzle into the bottom of the furnace, the melting phase will be frozen and a hemispherical porous zone with a mushroom head shape will be formed around the nozzle. The mushroom head can pro- tect the jet nozzle and mitigate the liquid spray on the surface of melt. In order to analyze the formation process of a mushroom head in the bottom-blown smelting furnaces, a hydraulic experiment system was designed and the formation of the mushroom head was investigated by hydraulic experiment. The hydrau- lic experiment results show that the formation process is mainly divided into generating crushing genera- ting process and stable mushroom head generation process. The formation of stable mushroom head re- quires certain thermodynamic condition and water splash is more intense without a mushroom head than with a mushroom head. The size, porosity and diameter of the mushroom head are affected by the flow rate, temperature and heat capacity of the bottom-blowing gas and the temperature of the superheat and the physical parameters of the melt.

关键词： Bottom-blown smelting furnace Mushroom head Hydraulic experiment Thermal equilibrium Similarity criterion

Precise 3D shape measurement of three-dimensional digital image correlation for complex surfaces

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Science China(Technological Sciences) 2018年第1期61卷 68-73页

作者： YAN TianHao su yong ZHANG QingChuan CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics University of Science and Technology of China

Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of digital image correlation （DIC） has been thoroughly studied theoretically and numerically, verification experiments have seldom been performed, especially fbr complex surfaces with a small field of view （FOV）. In this work, the shape of a 1-yuan coin was measured using 3D-DIC; the shape was complex due to the presence of many fine details, and the FOV was relatively small because the coin diameter was only 25 mm. During the experiment, a novel strategy for speckle production was developed： white paint was simply sprayed onto the surface. Black paint was not used; instead, taking advantage of the reflective nature of the coin surface, polarized light and a Polaroid filter were introduced, and the polarization direction was carefully adjusted, ensuring that the spray pattern was extremely thin and that high-quality speckle images with significant contrast were captured. The three-dimensional coin shape was also successfully determined for comparison using a stylus profiler. The results demonstrate that 3D-DIC provides high precision in shape measurement even for complex surfaces with small FOV. The precision of 3D-DIC can reach 1/7000 of the field of view, corresponding to about 6 ~tm in this experiment.

关键词： three-dimensional digital image correlation(3D-DIC) measurement precision complex surfaces small field of view polarized light polaroid filter

The Minimal Free Resolution of a Fat Star-Configuration in Pn

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Algebra Colloquium 2014年第1期21卷 157-166页

作者： Jeaman Ahn yong su Shin Department of Mathematics Education Kongju National University 182 Shinkwan-dong Kongju Chungnam 314-701 Korea Department of Mathematics Sungshin Women's University Seoul 136-742 Korea

Abstract. We find the minimal free resolution of a fat star-configuration X in Pn of type （r, s,t） defined by general forms of degrees d1,...,dr, and show that a fat linear star- configuration X in P2 never has generic Hilbert function if （s,t） ≠ （1, 1） or （2, 2）. These two results generalize the interesting results of [2].

关键词： Hilbert functions minimal free resolutions weak Lefschetz property fat star-configurations

Direct high-resolution X-ray imaging exploiting pseudorandomness

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Light(Science & Applications) 2023年第5期12卷 776-788页

作者： KyeoReh Lee Jun Lim su yong Lee yongKeun Park Department of Physics Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea KAIST Institute for Health Science and Technology Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and TechnologyPohangKyungbuk 37637Republic of Korea Tomocube Inc Daejeon 34051Republic of Korea

Owing to its unique penetrating power and high-resolution capability,X-ray imaging has been an irreplaceable tool since its *** the significance,the resolution of X-ray imaging has largely been limited by the technical difficulties on X-ray lens *** lensless imaging methods have been proposed,but are yet relying on multiple measurements or additional constraints on measurements or *** we present coherent specklecorrelation imaging(CSI)using a designed X-ray *** has no prerequisites for samples or ***,from a single shot measurement,the complex sample field is retrieved based on the pseudorandomness of the speckle intensity pattern,ensured through a *** achieve a spatial resolution of 13.9 nm at 5.46 keV,beating the feature size of the diffuser used(300 nm).The high-resolution imaging capability is theoretically explained based on fundamental and practical *** expect the CSI to be a versatile tool for navigating the unexplored world of nanometer.

关键词： resolution speckle replace

Growth Mechanism and Characterization of Single-crystalline Ga-doped SnO2 Nanowires and Self-organized SnO2/Ga2O3 Heterogeneous Microcomb Structures

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Chinese Journal of Chemical Physics 2008年第2期21卷 181-186页

作者： yong su Liang Xu Xue-mei Liang Yi-qing Chen School of Materials Science and Engineering Hefei University of Technology Hefei 230009 China Hefei General Machinery Research Institute Hefei 230031 China

Single-crystalline Ga-doped SnO2 nanowires and SnO2：Ga2O3 heterogeneous microcombs were synthesized by a simple one-step thermal evaporation and condensation method. They were characterized by means of X-ray powder diffraction （XRD）, field-emission scanning electron microscopy （FE-SEM）, energy-dispersive X-ray spectroscopy （EDS）, transmission electron microscopy （TEM） and selected-area electron diffraction （SAED）. FE-SEM images showed that the products consisted of nanowires and mierocombs that represent a novel morphology. XRD, SAED and EDS indicated that they were single-crystalline tetragonal SnO2. The influence of experimental conditions on the morphologies of the products is discussed. The morphology of the product showed a ribbon-like stem and nanoribbon array aligned evenly along one or both side of the nanoribbon. It was found that many Ga2O3 nanoparticles deposited on the surface of the microcombs. The major core nanoribbon grew mainly along the [110] direction and the self-organized branching nanoribbons grew epitaxially along [110] or [110] orientation from the （110） plane of the stem. A growth process was proposed for interpreting the growth of these remarkable SnO2：Ga2O3 heterogeneous microcombs. Due to the heavy doping of Ga, the emission peak in photoluminescence spectra has red-shifted as well as broadened significantly.

关键词： Microcomb Nanoribbon Photoluminescence

Blind channel identication of nonlinear folding mixing model

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Journal of Systems Engineering and Electronics 2006年第3期17卷 509-512页

作者： su yong Xu Shangzhi Ye Zhongfu Inst. of Statistical Signal Processing Dept. of Electronic Engineering and Information Science Univ. of Science and Technology of China Hefei 230027 P. R. China

Signals from multi-sensor systems are often mixtures of （statistically） independent sources by unknown mixing method. Blind source separation（BSS） and independent component analysis（ICA） are the methods to identify/recover the channels and the sources. BSS/ICA of nonlinear mixing models are difficult problems. For instance, the post-nonlinear model has been studied by several authors. It is noticed that in most cases, the proposed models are always with an invertible mixing. According to this fact there is an interesting question, how about the situation of the non-invertible non-linear mixing in BSS or ICA？ A new simple non-linear mixing model is proposed with a kind of non-invertible mixing, the folding mixing, and method to identify its channel, blindly.

关键词： blind channel identication non-linear mixing non-invertible.

Shrub Communities and Environmental Variables Responsible for Species Distribution Patterns in an Alpine Zone of the Qilian Mountains, Northwest China

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Journal of Mountain Science 2015年第1期12卷 166-176页

作者： HUO Hong FENG Qi su yong-hong Key Laboratory of Ecohydrology of Inland River Basin Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences

Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.

关键词： Alpine shrublands Floristic composition Cluster analysis Canonical Correspondence Analysis(CCA) Variation partitioning Species composition Species richness

Comparison of Fecal Methanogenic Archaeal Community Between Erhualian and Landrace Pigs Using Denaturing Gradient Gel Electrophoresis and Real-Time PCR Analysis

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Journal of Integrative Agriculture 2014年第6期13卷 1340-1348页

作者： su yong Hauke Smidt ZHU Wei-Yun Laboratory of Gastrointestinal Microbiology College of Animal Science and TechnologyNanjing Agricultural University Laboratory of Microbiology Agrotechnology and Food Sciences GroupWageningen University

Erhualian and Landrace breeds are typical genetically obese and lean pigs, respectively. To compare the fecal methanogenic Archaeal community between these two pig breeds, fecal samples from different growth phase pigs were collected and used for PCR-denaturing gradient gel electrophoresis （DGGE） with two primer pairs （344fGC/519r and 519f/915rGC） and real-time PCR analysis. Results showed that a better separation and higher quality of bands pattern were obtained in DGGE proifles using primers 344fGC/519r as compared with primers 519f/915rGC. Sequencing of DGGE bands showed that the predominant methanogens in the feces of Erhualian and Landrace pigs belonged to Methanobrevibacter spp. and Methanosphaera spp. Real-time PCR analysis revealed that there was no signiifcant difference in the numbers of fecal total methanogens between Erhualian and Landrace pigs;however, pig growth phase affected the numbers of 16S rRNA genes of total methanogens and Methanobrevibacter smithii. Dissociation curves of methyl coenzyme-M reductase subunit A （mcrA） gene fragments ampliifed with real-time PCR showed all samples possessed a single peak at 82＆#176;C, which might be associated with M. smithii. Samples from the same growth phase of each breed showed good replicative dissociation curves. The results suggest that the growth phase （including diet factor） other than genotype of pig may affect the fecal methanogenic Archaeal community of pigs.

关键词： methanogenic Archaea Erhualian pig Landrace pig Methanobrevibacter smithii