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Numerical Study of Boundary Layer Structure and Rainfall after Landfall of Typhoon Fitow(2013): Sensitivity to planetary Boundary Layer Parameterization

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Advances in Atmospheric Sciences 2019年第4期36卷 431-450页

作者： Meiying DONG Chunxiao JI Feng CHEN Yuqing WANG Zhejiang Institute of Meteorological Sciences International Pacific Research Center and Department of MeteorologySchool of Ocean and Earth Science and TechnologyUniversity of Hawaii at Manoa

The boundary layer structure and related heavy rainfall of Typhoon Fitow(2013), which made landfall in Zhejiang Province, China, are studied using the Advanced Research version of the Weather Research and Forecasting model, with a focus on the sensitivity of the simulation to the planetary boundary layer parameterization. Two groups of experiments—one with the same surface layer scheme and including the Yonsei University(YSU), Mellor–Yamada–Nakanishi–Niino Level 2.5,and Bougeault and Lacarrere schemes; and the other with different surface layer schemes and including the Mellor–Yamada–Janjic′ and Quasi-Normal Scale Elimination schemes—are investigated. For the convenience of comparative analysis, the simulation with the YSU scheme is chosen as the control run because this scheme successfully reproduces the track, intensity and rainfall as a whole. The maximum deviations in the peak tangential and peak radial winds may account for 11% and 33%of those produced in the control run, respectively. Further diagnosis indicates that the vertical diffusivity is much larger in the first group, resulting in weaker vertical shear of the tangential and radial winds in the boundary layer and a deeper inflow layer therein. The precipitation discrepancies are related to the simulated track deflection and the differences in the simulated low-level convergent flow among all tests. Furthermore, the first group more efficiently transfers moisture and energy and produces a stronger ascending motion than the second, contributing to a deeper moist layer, stronger convection and greater precipitation.

关键词： planetary boundary layer parameterization landfalling typhoon boundary layer structure rainfall

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Improved dissolution and oral absorption by co-grinding active drug probucol and ternary stabilizers mixtures with planetary beads-milling method

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Asian Journal of Pharmaceutical Sciences 2019年第6期14卷 649-657页

作者： Fang Li Linsen Li Shaoning Wang Yan Yang Jia Li Dongchun Liu Sijie Zhang Siling Wang Hui Xu School of Pharmacy Shenyang Pharmaceutical UniversityBenxi 117004China Shenyang Medical College Shenyang 110031China School of Pharmaceutical Engineering Shenyang Pharmaceutical UniversityBenxi 117004China School of Traditional Chinese Medicine Shenyang Pharmaceutical UniversityBenxi 117004China

The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-milling equipment was utilized to grind the raw probucol to ultrafine nanoparticle/nanocrystal aqueous suspension that was further solidified by freeze-drying process.Cellulose derivatives of different substitution groups and molecular weights,including HPMC,HPC,and MC,were evaluated as the primary stabilizer of probucol nanosuspension.Ternary stabilizers system composed of a primary stabilizer(cellulose derivative,i.e.HPC),a nonionic surfactant(Pluronic R F68),and an anionic surfactant(SDS)was employed to obtain probucol nanosuspension of finer particle size and enhanced dissolution in aqueous media.The probucol nanosuspension with good physical stability showed no obvious change of particle size even after storing over 7 d at 4°C or 25°C.The solidified probucol nanosuspension with trehalose as the cryoprotectant showed the highest dissolution rate(>60%at 2 h)compared to other cryoprotectant.The in vivo pharmacokinetic evaluation indicated about 15-folds higher AUC value of the probucol nanosuspension compared to that of coarse probucol suspension after oral administration to rats.The probucol nanosuspension prepared by wet-milling and ternary stabilizers system may find wide applications for improving the dissolution and oral absorption of water-insoluble drugs.

关键词： Probucol Nanosuspension Ternary stabilizers systems planetary beads-milling Bioavailability

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Chinese Academy of Sciences’ recent activities in boosting Chinese planetary science research

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Earth and planetary Physics 2019年第5期3卷 459-466页

作者： Su-Fang Hu Yong Wei Institute of Geology and Geophysics Chinese Academy of Sciences

The Chinese Academy of Sciences and its affiliated institutes and universities,responding to ever-increasing needs of China’s space explorations and exploitations in recent years,have taken a series of initiatives an... 详细信息

关键词： Chinese Academy of Sciences planetary science space explorations and exploitations capacity-building

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A Morphological Study of Two Young Multipolar planetary Nebulae

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Research in Astronomy and Astrophysics 2023年第3期23卷 170-182页

作者： Shi-Bo Wen Chih-Hao Hsia Xiao-Xi Kang Rui Chen Tao Luo State Key Laboratory of Lunar and planetary Sciences Macao University of Science and Technology.MacaoChina The Laboratory for Space Research Faculty of ScienceThe University of Hong KongChina Deep Space Exploration Laboratory Beijing 100043China Lunar Exploration and Space Engineering Center China National Space AdministrationBeijing 100190China Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou 511442China Zhuhai Bojay Electronics Co. Ltd.Zhuhai 519075China

We carry out an optical morphological and infrared spectral study for two young planetary nebulae(PNs)Hen2-158 and Pe 1-1 to understand their complex shapes and dust properties.Hubble Space Telescope optical images reveal that these nebulae have several bipolar-lobed structures and a faint arc with a clear boundary is located at the northwestern side of Pe 1-1.The presence of this arc-shaped structure suggests that the object interacts with its nearby interstellar medium.Spitzer IRS spectroscopic observations of these young nebulae clearly show prominent unidentified infrared emission features and a weak silicate band in Pe 1-1,indicating that Hen 2-158 is a carbonrich nebula and Pe 1-1 has a mixed chemistry dust environment.Furthermore,we construct two three-dimensional models for these PNs to realize their intrinsic structures.The simulated models of the nebulae suggest that multipolar nebulae may be more numerous than we thought.Our analyses of spectral energy distributions for Hen 2-158 and Pe 1-1 show that they have low luminosities and low stellar effective temperatures,suggesting that these nebulae are young PNs.A possible correlation between typical multipolar young PNs and nested nebulae is also discussed.

关键词： northwestern stellar planetary

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Dynamic characteristics of the planetary gear train excited by time-varying meshing stiffness in the wind turbine

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International Journal of Minerals,Metallurgy and Materials 2018年第9期25卷 1104-1112页

作者： Rui-ming Wang Zhi-ying Gao Wen-rui Wang Yang Xue De-yi Fu State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems China Electric Power Research Institute School of Mechanical Engineering University of Science and Technology Beijing

Wind power has attracted increasing attention as a renewable and clean energy. Gear fault frequently occurs under extreme environment and complex loads. The time-varying meshing stiffness is one of the main excitations. This study proposes a 5 degree-of-freedom torsional vibration model for the planetary gear system. The influence of some parameters(e.g., contact ratio and phase difference) is discussed under different conditions of a single teeth pair and double pairs of teeth. The impact load caused by the teeth face fault, ramped load induced by the complex wind conditions, and the harmonic excitation are investigated. The analysis of the time-varying meshing stiffness and the dynamic meshing force shows that the dynamic design under different loads can be made to avoid resonance, can provide the basis for the gear fault location of a wind turbine, and distinguish the fault characteristics from the vibration signals.

关键词： wind turbine planetary gear time-varying meshing stiffness dynamic characteristics

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Translational - torsional coupled model based nonlinear dynamic analysis of an NGW planetary gear train

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Journal of Chongqing University 2016年第4期15卷 159-167页

作者：刘振州张俊 BIAN Shi-yuan School of Mechanical Engineering Anhui University of Technology Ma'anshan 243032 P. R. China School of Mechanical Engineering and Automation Fuzhou University Fuzhou 350116 P. R. China

This paper aims to investigate the nonlinear dynamic behaviors of an NGW planetary gear train with multi-clearances and manufacturing/assembling errors. For this purpose, an analytical translational- torsional coupled dynamic model is developed considering the effects of time-varying stiffness, gear backlashes and component errors. Based on the proposed model, the nonlinear differential equations of motion are derived and solved iteratively by the Runge-Kutta method. An NGW planetary gear reducer with three planets is taken as an example to analyze the effects of nonlinear factors. The results indicate that the backlashes induce complicated nonlinear dynamic behaviors in the gear train. With the increment of the backlashes, the gear system has experienced periodic responses, quasi-periodic response and chaos responses in sequence. When the planetary gear system is in a chaotic motion state, the vibration amplitude increases sharply, causing severe vibration and noise. The present study provides a fundamental basis for design and parameter optimization of NGW planetary gear trains.

关键词： NGW planetary gear train time-varying stiffness nonlinear dynamic model gear backlash Runge-Kutta method

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New detected CO (1-0) emission from planetary nebulae

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Science China Mathematics 2000年第2期43卷 217-224页

作者：孙锦孙艳春 Department of Astronomy Beijing Normal University Beijing China

We report the results of CO(1-0 (J = 1 -0) observations for 20 selected planetary nebulae (PNe), using the 13.7 m radio telescope of Purple Mountain Observatory at the Qinghai Station. Due to weak CO(1-0) emission, long integrated time observations have been carried out for most of sampled PNe. Among these PNe, nine are first detections in CO(1-0) named NGC6445, M1-59, M4-9, M2-51, M4-18, He2-459, Sh2-71, K3-31, M2-52, and one is the first possible detection named V-V1-8, a probably misclassified PN. NGC6445, Ml-59, M4-9 and M2-51 have been detected in CO(2-1) (J = 2-1). Although having been observed in previous CO surveys, Sh2-71 and M4-18 were not detected in CO; M2-52, K3-31, He2-459 are the first detected PNe in CO emission and V-V1-8 is given with a first completed spectrum detected in CO(1-0). Comparing these data with other previous observational ones, we discuss the relationships between CO(1-0) emission and evolution of PNe: While the nebular radii increase, the CO(1-0) line integrated

关键词： planetary nebulae CO emission molecular envelope stellar evolution.

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On planetary Electromagnetism and Gravity

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International Journal of Astronomy and Astrophysics 2011年第2期1卷 62-66页

作者： Ashwini Kumar Lal Town & Country Planning Organisation

Study of the interiors of the various terrestrial planets, as presented in the paper, leads to the possibility of planetary gravity being linked to the electromagnetism generated in the planetary interiors. Findings of the study undertaken suggest that Earth’s gravitational attraction may be attributed to magnetic coupling experi-enced between Earth's electromagnetism and all the earthly objects - electrically charged or uncharged. More precisely, terrestrial gravity is deemed to be outcome of the bound state of the planetary electromagnetism.

关键词： Electromagnetism Gravity planetary Dynamo Coriolis Force Earth Venus Mars Mercury

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Effect of Carbon and Sulfur on Iron Melting at High Pressure:Implications for Composition and Evolution of the planetary Terrestrial Cores

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地学前缘 2009年第S1期16卷 204-204页

作者： L.W.Deng~1,Y.W.Fei~2,X.Liu~1,Z.Z.Gong~3 1.School of Earth and Space Science,Peking University,Beijing 100871,China. 2.Geophysical Laboratory,Carnegie Institution of Washington,5251 Broad Branch Road,NW,DC 20015,USA 3.Institute of Spacecraft Environment Engineering,Beijing 100094,China

The presence of light element(s)in the Earth’s core is necessary in order to explain the observed density and velocity discrepancy for the core(Anderson and Ahrens,1994).O,Si,S,C and H were suggested as potential candidates based on cosmochemical considerations(Stevenson,1981).High-pressure experiment results,in conjunction with theoretical and cosmochemical evidences,argued that it is difficult for any one of them to account for the core

关键词： sulfur-carbon-iron high pressure melting planetary core

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The Effectiveness of Model Rocketry to Teach Science and Quantitative Content to Students in a Non-Science Majors Course at the College Level: An Example from a planetary Geology Course

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Open Journal of Statistics 2020年第1期10卷 139-153页

作者： Nicholas P. Lang Department of Geology Mercyhurst University Erie PA USA

Engaging non-science majors in a college-level science course can prove challenging. In turn, this can make it difficult to effectively teach science and math content. However, topics related to planetary exploration have a unique way of capturing one’s imagination and may serve to robustly engage non-science majors. In this contribution, I 1) describe a model rocketry lab module,?I have created and implemented into an introductory-level planetary geology course and 2) quantify student learning gains as a result of this module. This module builds on model rocketry lesson plans for science and math coursework at the K-12 level (e.g., [1]?[2])?and involves students working in groups to 1) design and build model rockets to carry out a theoretical mission that addresses a science question the students have developed, 2) launch their rockets and collect related data, 3) synthesize and evaluate their data, and 4) report their results in both oral and written forms. The tasks of building and launching the model rocket serve as a vehicle that allows students to employ the scientific process while learning about planetary mission design and applying geologic and quantitative skills useful to answering a science-related question. Quantification of student learning gains shows that through this lab module, students significantly improved their quantitative and scientific reasoning skills. Results from student questionnaires showed a significant increase in student interest and confidence in addressing scientific questions as well as an understanding of how planetary missions are designed and conducted.

关键词： Introductory Geology Non-Science Major planetary Geology Model Rocketry

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