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Study on fluctuations of plume front and turbidity maximum in the Hangzhou Bay by remote sensing data

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Acta Oceanologica Sinica 1993年第1期12卷 51-62页

作者： Li Yan Li Jing Su Jilan and Ren Fuhu Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012. China Institute of Remote Sensing, Peking University, Beijing 100871, China Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China China

On the basis of the time series of AVHRR data from NOAA satellites and the geographical information system PURSIS, fluctuations of the plume front and the turbidity maximum in the Hangzhou Bay, reflected by the distributions of temperature and suspended sediment concentration respectively, are studied in view of long-term behaviors or seasonal and tidal cycles. The data suggest that the effect of front plays an important role in the development of the turbidity maximum close to the Changjiang Estuary > while the effect of tide dominates over the development of another very turbid water situated in the shoal areas in the southern Hangzhou Bay.

关键词： esturary front suspended sediment remote sensing geographical information system Hangzhou Bay

Animal stem cells: the engineering development front of 2018

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frontiers of Agricultural Science and Engineering 2019年第1期6卷 93-95页

作者： Wenye YUAN Jianxiang XU Chenying LI Lijuan SHI Aidong YANG Yan WANG Lu XING Shaozhong KANG Division of Scientific R&D China Agricultural University Division of Natural Science Academic Publishing Higher Education Press Library China Agricultural University Center for Agricultural Water Research in China China Agricultural University

The Engineering fronts reports are important guidelines for the future development directions of engineering science and technology. The Chinese Academy of Engineering (CAE) has been conducting studies relevant to Eng... 详细信息

关键词： MA the engineering development front of 2018 Animal stem cells

Deep soil water recharge response to precipitation in Mu Us Sandy Land of China

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Water Science and Engineering 2018年第2期11卷 139-146页

作者： Yi-ben Cheng Hong-bin Zhan Wen-bin Yang Fang Bao School of Soil and Water Conservation Beijing Forestry University Institute of Desertification Studies Chinese Academy of Forestry Department of Geology & Geophysics Texas A&M University College Station

Soil water is the main form of water in desert areas, and its primary source is precipitation, which has a vital impact on the changes in soil moisture and plays an important role in deep soil water recharge(DSWR) in sandy areas. This study investigated the soil water response of mobile sand dunes to precipitation in a semi-arid sandy area of China. Precipitation and soil moisture sensors were used to simultaneously monitor the precipitation and the soil water content(SWC) dynamics of the upper 200-cm soil layer of mobile sand dunes located at the northeastern edge of the Mu Us Sandy Land of China in 2013. The data were used to analyze the characteristics of SWC, infiltration, and eventually DSWR. The results show that the accumulated precipitation(494 mm) from April 1 to November 1 of 2013 significantly influenced SWC at soil depths of 0-200 cm. When SWC in the upper 200-cm soil layer was relatively low(6.49%), the wetting front associated with53.8 mm of accumulated precipitation could reach the 200-cm deep soil layer. When the SWC of the upper 200-cm soil layer was relatively high(10.22%), the wetting front associated with the 24.2 mm of accumulated precipitation could reach the upper 200-cm deep soil layer. Of the accumulated 494-mm precipitation in 2013, 103.2 mm of precipitation eventually became DSWR, accounting for 20.9% of the precipitation of that year. The annual soil moisture increase was 54.26 mm in 2013. Accurate calculation of DSWR will have important theoretical and practical significance for desert water resources assessment and ecological construction.

关键词： Mu Us Sandy Land Sandy land DSWR Precipitation Wetting front

frontsand strong currents of the upper southeast Indian Ocean

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Acta Oceanologica Sinica 2006年第2期25卷 1-24页

作者： HE Zhigang DONG Zhaoqian YUAN Xiaojun Department of Oceanography Xiamen University Xiamen 361005 China Polar Research Institute of China Shanghai 200136 China Lamont-Doherty Earth Observatory Columbia University Palisades New York NY 10964-800 USA

Hydrographic data, ADCP velocity and sea level anomaly derived from the satellite altimeter have been jointly analyzed in the southeast lndian Ocean. Results show the locations and orientations of the major oceanic fronts as well as the characteristics of the currents within these fronts in the area. Double subtropical fronts are observed in the section along 120°E, which conflicts with the frontal structure frequently observed before the North Subtropical front （NSTF） and South Subtropical front （SSTF） merge into a single STF between 110°-115°E. The Subantarctic front （SAF）, influenced by the out-of-phase double eddies, runs across 48°S three times between 120° and 127°E. The surface current within the SAF is strengthened up to 105.4 cm/s by the geostrophic effect of these eddies. Furthermore eddies may cause the strong current to split up into two branches within the SAF. The SAF and the primary polar front （PFI） can be identified individually in the ADCP data with a separation distance of about 0.3° at latitude between 140° and 145°E, although they cannot be identified separately in the low-resolution hydrographic data. The different thcrmohaline characteristics of Circumpolar Deep Water （CDW） and Modified Circumpolar Deep Water （MCDW） result in the formation of Southern Antarctic Circumpolar Current front （SACCF） in the southeast Indian Ocean. It consistently turns northward along the east flank of the Kerguclen Plateau after it runs through the Princess Elizabeth Trough and turns southward sharply north of 60°S with a little seasonal variations. It is shown that the locations and orientations of the SAK the primary PF and SACCF in the ACC of the southeast Indian Ocean can be identified more precisely by the current distribution derived from ADCP data than by hydrographic data, because these fronts are usually accompanied by strong currents. However, the locations and orientations of the STF and the secondary PF are more difficult to be identified through current data, since these two fronts are usually no

关键词： southeast Indian Ocean front jet

A Light-Cone QCD Inspired Meson Model with a Relativistic Confining Potential in Momentum Space

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Chinese Physics Letters 2007年第2期24卷 374-377页

作者：黎雷王顺金周善费张光彪 School of Science Southwest University of Science and Technology Mianyang 621010 Department of Physics Sichuan University Chengdu 610064 Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100080 Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator Lanzhou 730000 School of Physics and Electronics Henan University Kaifeng 475004

For describing the radial excited states a relativistic confining potential in momentum space is included in the meson effective light-cone Hamiltonian. The meson eigen equations are transformed from the front form to the instant form and formulated in total angular representation. Details about numerically solving these equations are discussed, mainly focusing on treating singularities arising from one-gluon exchange interactions and confinement. The results of pseudo-scalar mesons indicate that the improved meson effective light-cone Hamiltonian can describe the ground states and radial excited states well. Some radial excited states are also predicted and waiting for experimental test.

关键词： SPECTROSCOPY EQUATIONS front

Aerodynamic optimization of rotor airfoil based on multi-layer hierarchical constraint method

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Chinese Journal of Aeronautics 2016年第6期29卷 1541-1552页

作者： Zhao Ke Gao Zhenghong Huang Jiangtao Li Quan The First Aircraft Institute of AVIC Xi’an 710089China National Key Laboratory of Aerodynamic Design and Research Northwestern Polytechnical UniversityXi’an 710072China China Aerodynamics Research and Development Center Mianyang 621000China

Rotor airfoil design is investigated in this paper. There are many difficulties for this highdimensional multi-objective problem when traditional multi-objective optimization methods are used. Therefore, a multi-layer hierarchical constraint method is proposed by coupling principal component analysis(PCA) dimensionality reduction and e-constraint method to translate the original high-dimensional problem into a bi-objective problem. This paper selects the main design objectives by conducting PCA to the preliminary solution of original problem with consideration of the priority of design objectives. According to the e-constraint method, the design model is established by treating the two top-ranking design goals as objective and others as variable constraints. A series of bi-objective Pareto curves will be obtained by changing the variable constraints, and the favorable solution can be obtained by analyzing Pareto curve spectrum. This method is applied to the rotor airfoil design and makes great improvement in aerodynamic performance. It is shown that the method is convenient and efficient, beyond which, it facilitates decision-making of the highdimensional multi-objective engineering problem.

关键词： Multi-layer hierarchical constraint method Multi-objective optimization NSGA II Pareto front Principal component analysis Rotor airfoil

Characteristics of combustion zone and evolution of mineral phases along bed height in ore sintering

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International Journal of Minerals,Metallurgy and Materials 2017年第10期24卷 1087-1095页

作者： Yao-zu Wang Jian-liang Zhang Zheng-jian Liu Ya-peng Zhang Dong-hui Liu Yi-ran Liu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

Quantitative parameters of bed combustion, including the thickness of the combustion zone(TCZ), the maximum temperature of the combustion zone(MTCZ), and the bed shrinkage, were characterized through a series of sinter pot tests in transparent quartz pots. The results showed that TCZ first ascended and then descended as the sintering process proceeded. The sintering process was divided into four stages according to the variation rate of the TCZ. A "relative-coordinate" method was developed to obtain the actual reaction temperature of sinter along the height direction. With increasing the sintering temperature, the reactants transformed and entered into liquid phases. The mineral composition and microstructure of the sinter were characterized through X-ray diffraction and scanning electron microscopy–energy-dispersive X-ray spectroscopy. Liquid phases with greater Fe and Al contents were more likely to form acicular-like silico-ferrite of calcium and aluminum after crystallization because of the outward spread of Al, which led to a better fluidity of the liquid. An evolution mechanism of "solid-state reaction—liquid phases formation—crystallization" of the mineral phases is proposed.

关键词： flame front mineral phases sintering evolution mechanism transparent quartz pots

Beam test results of high Q CBPM prototype for SXFEL

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Nuclear Science and Techniques 2017年第4期28卷 51-58页

作者： Jian Chen Yong-Bin Leng Lu-Yang Yu Long-Wei Lai Ren-Xian Yuan Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201204 China University of the Chinese Academy of Sciences Beijing 100049 China

In pursuit of high-precision beam position measurements at micrometers or submicrometers for the Shanghai soft X-ray free-electron laser(SXFEL) facility which is under construction in the vicinity of the Shanghai Synchrotron Radiation Facility,a high Q cavity beam position monitor(CBPM) with a resonant frequency of4.7 GHz is developed by the Shanghai Institute of Applied Physics,and the relevant BPM electronics with a dedicated RF front end,and a digital BPM,are completed.The cavity design,cold test,system architecture,and first beam test are performed at the Shanghai deep ultraviolet free-electron laser(Zhao et al.in Nucl Instrum Meth A 528(1-2):591-594,2004.doi:10.1016/j.nima.2004.04.108) facility.Results of the beam experiment show that the performance of the CBPM is consistent with basic expectations,and the beam position resolution can fulfill the requirements for the SXFEL project if the beam conditions are optimized.

关键词： High Q CBPM SXFEL Position resolution RF front end DBPM

Unusual coastal ocean cooling in the northern South China Sea by a katabatic cold jet associated with Typhoon Mujigea(2015)

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Acta Oceanologica Sinica 2019年第5期38卷 62-75页

作者： Yuxin Shi Lingling Xie Quanan Zheng Shuwen Zhang Mingming Li Junyi Li Guangdong Key Laboratory of Coastal Ocean Variation and Disaster Prediction Guangdong Ocean University Department of Atmospheric and Oceanic Science University of Maryland

This study deals with a unusual cooling event after Typhoon Mujigea passed over the northern South China Sea(SCS) in October 2015. We analyze the satellite sea surface temperature(SST) time series from October 3 to 18,2015 and find that the cooling process in the coastal ocean had two different stages. The first stage occurred immediately after typhoon passage on October 3, and reached a maximum SST drop of –2℃ on October 7 as the usual cold wake after typhoon. The second stage or the unusual extended cooling event occurred after 7d of the typhoon passage, and lasted for 5d from October 10 to 15. The maximum SST cooling was –4℃ and occurred after 12d of typhoon passage. The mechanism analysis results indicate that after landing and moving northwestward to the Yunnan-Guizhou Plateau(YGP), Typhoon Mujigea(2015) met the westerly wind front on October 5. The lowpressure and positive-vorticity disturbances to the front triggered meridional air flow and low-pressure trough,thus induced a katabatic cold jet downward from the Qinghai-Tibet Plateau(QTP) passing through the YGP to the northwestern SCS. The second cooling reached the maximum SST drop 4d later after the maximum air temperature drop of –9℃ on October 11. The simultaneous air temperature and SST observations at three coastal stations reveal that it is this katabatic cold jet intrusion to lead the unusual SST cooling event.

关键词： Typhoon Mujigea(2015) second-round cooling katabatic cold jet South China Sea westerly wind front