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An empirical L-band scintillation model for a mid-latitude station,Weihai, China during the low solar activity period

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Science China(Technological Sciences) 2019年第7期62卷 1182-1190页

作者： PRIYADARSHI Shishir zhang qing-he WANG Yong Shandong Provincial Key laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong University

Mid-latitude ionospheric scintillation has been studied in very poor proportion as compared to the equatorial and high latitude ionospheric scintillation. Mid-latitude ionospheric scintillations are often associated with either day time photo-ionization or due to the storm enhanced density. Using the phase screen model and the wave propagation theory in random media, we have identified the orientation of the ionospheric irregularities over Weihai with the local geomagnetic field. Amplitude and phase scintillation data observed using global positioning system(GPS) scintillation receiver deployed at the mid-latitude observation station Weihai, have been used along with K-index derived from the horizontal magnetic field component of the local magnetometer. The proposed model uses the scintillation indices relationship with the local K-index. We identified the scintillation dependence over local K-index during geomagnetic quiet and disturbed condition. This dependence coefficient is used on the real scintillation data for modeling. The presented scintillation model has been validated by comparing it to the real observations. The co-relation coefficient is more than 90% during the disturbed as well as quiet geomagnetic conditions.

关键词： mid-latitude ionosphere scintillation GPS global navigation satellite systems (GNSS)

Development of A Depth-Integrated Longshore Current Model with Unstructured Grids

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China Ocean Engineering 2016年第5期30卷 718-732页

作者： CheN Chao zhang qing-he State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Tianjin 300072 China

A depth-integrated model for simulating wave-induced longshore current was developed with unstructured grids. Effects of surface roller and horizontal mixing under combined waves and currents were incorporated in the numerical model. Recommended values of model coefficients were also proposed based on sensitivity analysis. Field observations and three series of laboratory measurements including two cases conducted on the plane beach and one implemented on the ideal inlet were employed to examine the predictive capability of this model. For the field case and laboratory cases conducted on the plane beach, numerical results were compared favorably with the measured data. For the case with an ideal inlet, simulated circulation pattern is supposed to be reasonable although some deviations between numerical results and measured data still can be detected.

关键词： longshore current numerical model unstructured grids surface roller horizontal mixing

Numerical Simulations of Coastal Overwash Using A Phase-Averaged Wave−Current−Sediment Transport Model

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China Ocean Engineering 2022年第2期36卷 191-207页

作者： LI Song-zhe JI Chao zhang qing-he CheN Tong-qing State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300350China Key Laboratory of Engineering Sediment Tianjin Research Institute for Water Transport EngineeringMinistry of TransportTianjin 300456China

Coastal overwash is a natural phenomenon that commonly occurs during storm events and can cause considerable changes in nearshore morphology within a short *** this study,a complete set of empirical overwash transport algorithms is developed and introduced into a phase-averaged wave-current-sediment transport coupling model that integrates the Finite-Volume Community Ocean Model(FVCOM)and the Simulating Waves Nearshore(SWAN)*** resulting morphological evolution model can simulate coastal *** against the data obtained from multiple sets of laboratory overwash experiments demonstrates that the model performs relatively well in simulating morphological changes caused by runup overwash and inundation overwash under different hydrodynamic and beach profile *** sensitivity of each empirical coefficient in the overwash transport algorithms is comprehensively *** effects of each coefficient on the output of the model are discussed,and a recommended value range is provided for each coefficient.

关键词： wave-current coupling phase-averaged model overwash wave runup morphological evolution

A Higher-Efficient Non-Hydrostatic Finite Volume Model for Strong Three-Dimensional Free Surface Flows and Sediment Transport

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China Ocean Engineering 2017年第6期31卷 736-746页

作者： LIU Xin MA Dian-guang zhang qing-he State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Key Laboratory of Engineering Sediment of Ministry of Communications Tianjin Research Institute for Water Transport Engineering

In order to accurately simulate strong three-dimensional （3-D） free surface flows and sediment transport, the fully 3- D non-hydrostatic pressure models are developed based on the incompressible Navier-Stokes equations and convection-diffusion equation of sediment concentration with the mixing triangle and quadrilateral grids. The governing equations are discretized with the unstructured finite volume method in order to provide conservation properties of mass and momentum, and flexibility with practical application. It is shown that it is first-order accurate on nonuniform plane two-dimensional （2-D） grids and second-order accurate on uniform plane grids. A third-order approximation of the vertical velocity at the top-layer is applied. In such a way, free surface zero stress boundary condition is satisfied maturely, and very few vertical layers are needed to give an accurate solution even for complex discontinuous flow and short wave simulation. The model is applied to four examples to simulate strong 3-D free surface flows and sediment transport where non-hydrostatic pressures have a considerable effect on the velocity field. The newly developed model is verified against analytical solutions with an excellent agreement.

关键词： higher-efficient non-hydrostatic strong 3-D free surface flows sediment transport 3-D numerical model

Experimental Investigation of Local Scour Around A New Pile-Group Foundation for Offshore Wind Turbines in Bi-Directional Current

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China Ocean Engineering 2018年第6期32卷 737-745页

作者： JI Chao zhang Jin-feng zhang qing-he LI Ming-xing CheN Tong-qing State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Fourth Harbor Engineering Investigation and Design Institute Co. Ltd. China Communications Construction Company

The local scour around a new pile-group foundation of offshore wind turbine subjected to a bi-directional current was physically modeled with a bi-directional flow flume. In a series of experiments, the flow velocity and topography of the seabed were measured based on a system composed of plane positioning equipment and an *** results indicate that the development of the scour hole was fast at the beginning, but then the scour rate decreased until reaching equilibrium. Erosion would occur around each pile of the foundation. In most cases, the scour pits were connected in pairs and the outside widths of the scour holes were larger than the inner widths. The maximum scour depth occurred at the side pile of the foundation for each test. In addition, a preliminary investigation shows that the larger the flow velocity, the larger the scour hole dimensions but the shorter equilibrium time. The field maximum scour depth around the foundation was obtained based on the physical experiments with the geometric length scales of 1:27.0, 1:42.5 and 1:68.0, and it agrees with the scour depth estimated by the heC-18 equation.

关键词： offshore wind turbines new pile-group foundation local scour bi-directional current

Numerical Simulation of Random Wave Overtopping of Rubble Mound Breakwater with Armor Units

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China Ocean Engineering 2021年第2期35卷 176-185页

作者： LI Jing-yuan zhang qing-he LU Yong-jun State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing 210029China

Based on the open source code OpenFOAM,a three-dimensional model is presented for simulation of the interaction between waves and rubble mound breakwater with armor *** armor units with their real geometries are depicted through computational *** volume-averaged RANS equation and the seepage equation containing nonlinear term are used to describe the percolation in the core and underlayer of the *** independence analysis are carried out,the horizontal and vertical grid size are recommended to take as one-fifteenth of the mean nominal diameter D_(50) of the armor units and one-fifteenth of the wave height *** wave overtopping of rubble mound breakwater with armor units is simulated through the proposed *** results show good agreement between the simulated and measured overtopping discharge rates for different types of armor *** developed numerical model can be used to evaluate the random wave overtopping in design of rubble mound breakwater with artificial armor blocs.

关键词： random wave armor units seepage equation overtopping discharges grid independence

Construction of recombinant industrial Saccharomyces cerevisiae strain with bglS gene insertion into PEP4 locus by homologous recombination

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第7期9卷 527-535页

作者： Qiang zhang Qi-he CheN Ming-liang FU Jin-ling WANG Hong-bo zhang Guo-qing he Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China

The bglS gene encoding endo-1,3-1,4-β-glucanase from Bacillus subtil＆ was cloned and sequenced in this study. The bglS expression cassette, including PGK1 promoter, bglS gene fused to the signal sequence of the yeast mating pheromone a-factor （MFals）, and ADH1 terminator with G418-resistance as the selected marker, was constructed. Then one of the PEP4 allele of Saccharomyces cerevisiae WZ65 strain was replaced by bglS expression cassette using chromosomal integration of polymerase chain reaction （PCR）-mediated homologous recombination, and the bglS gene was expressed simultaneously. The recombinant strain S. cerevisiae （SC-βG） was preliminarily screened by the clearing hydrolysis zone formed after the barley β-glucan was hydrolyzed in the plate and no proteinase A （PrA） activity was measured in fermenting liquor. The results of PCR analysis of genome DNA showed that one of the PEP4 allele had been replaced and bglS gene had been inserted into the locus of PEP4 gene in recombinant strains. Different endo-1,3-1,4-β-glucanase assay methods showed that the recombinant strain SC-βG had high endo-1,3-1,4-β-glucanase expression level with the maximum of 69.3 U/（h·ml） after 60 h of incubation. Meanwhile, the Congo Red method was suitable for the determination of endo-1,3-1,4-β-glucanase activity during the actual brewing process. The current research implies that the constructed yeast strain could be utilized to improve the industrial brewing property of beer.

关键词： Endo-1 3-1 4-β-glucanase (bglS) Gene replacement Homologous recombination Bacillus subtilis PEP4 gene Saccharomyces cerevisiae

Changes in Texture and Retorting Yield in Oil Shale During Its Bioleaching by Bacillus Mucilaginosus

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Chemical Research in Chinese Universities 2013年第2期29卷 294-298页

作者： zhang Xue-qing REN he-jun LIU Na zhang Lan-ying ZHOU Rui Key Lab of Groudwater Resources and Environment Ministry of Education College of Environment and Resources Jilin University Changchun 130012 P. R. China

Bioleaching of oil shale by Bacillus mucilaginosus was carried out in a reaction column for 13 d. The pH value of the leaching liquor decreased steadily from 7.5 to 5.5 and the free silicon dioxide concentration reached approximately 200 mg/L in it. Scanning electron microscopy（SEM） observations revealed that a mass of small particles separated from the matrix of oil shale. Energy dispersive spectrometry（EDS） analysis implied that the total content of Si,O, A1 was decreased in the particle area of the matrix. These facts indicate that the silicate was removed, leading to the structural transformation of oil shale. Comparison of the shale oil yields before and after bioleaching illustrated that approximately 10% extra shale oil was obtained. This finding suggests that the demineralisation of the oil shale by silicate bacteria improves shale oil yield.

关键词： Oil shale Bacillus mucilaginosus Bioleaching Shale oil yield

基于能量原理的悬移质泥沙沿岸输沙率横向分布公式

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泥沙研究 2015年第4期40卷 66-73页

作者：陈超张庆河天津大学水利工程仿真与安全国家重点实验室天津300072

基于能量原理建立波流共存时的挟沙力公式,用于计算悬移质泥沙沿岸输沙率的横向分布。收集了共382个实测数据,确定公式中的能量传递系数。建立了波浪破碎能量传递系数与Dean数之间的关系。将公式计算结果与现场观测悬移质沿岸输沙率比较... 详细信息

基于能量原理建立波流共存时的挟沙力公式,用于计算悬移质泥沙沿岸输沙率的横向分布。收集了共382个实测数据,确定公式中的能量传递系数。建立了波浪破碎能量传递系数与Dean数之间的关系。将公式计算结果与现场观测悬移质沿岸输沙率比较,结果表明计算值与测量值吻合较好,公式能较合理地反映不同波浪条件下悬移质沿岸输沙率的横向分布规律。

关键词：沿岸输沙横向分布挟沙能力波流共存悬移质