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Hysteresis Loop of Energy Transfer in Two-Wave Mixing from 180° Domains in BaTiO_(3):Ce

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Chinese Physics Letters 1997年第2期14卷 100-102页

作者： wu jian-lao DAI jian-hua ZHANG Hong-jun Laboratory of Optical Physics Institute of Physics&Center for Condensed Matter PhysicsChinese Academy of SciencesBeijing 100080

This paper reports an experimental observation that a hysteresis loop of energy transfer versus an external electric field is obtained in photorefractive two-wave mixing,which originates from 180°domains presented in... 详细信息

关键词： crystal. mixing hysteresis

Incoherent scatter radar (ISR) observations of high-frequency enhanced ion and plasma lines induced by X/O mode pumping around the critical altitude

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Earth and Planetary Physics 2022年第4期6卷 305-312页

作者： Jun wu jian wu IHaggstrom Tong Xu ZhengWen Xu YanLi Hu National Key Laboratory of Electromagnetic Environment China Research Institute of Radio Wave PropagationBeijing 102206China European Incoherent Scatter Scientific Association(EISCAT) KirunaSE-98192Sweden

Analysis of Incoherent Scatter Radar(ISR)data collected during an experiment involving alternating O/X mode pumping reveals that the high-frequency enhanced ion line(HFIL)and plasma line(HFPL)did not appear immediately after the onset of pumping,but were delayed by a few *** examining the initial behaviors of the ion line,plasma line,and electron temperature,as well as ionosphere conditions,we find that(1)the HFIL and HFPL were delayed not only in the X mode pumping but also in the O mode pumping and(2)the HFIL was not observed prior to enhancement of the electron *** analysis suggests that(1)leakage of the X mode to the O mode pumping may not be ignored and(2)spatiotemporal uncertainties and spatiotemporal variations in the profiles of ion mass and electron density may have played important roles in the apparent failure of the Bragg condition to apply;(3)nevertheless,the absence of parametric decay instability(PDI)cannot be ruled out,due to our inability to match conditions caused by the spatiotemporal uncertainties.

关键词： Incoherent Scatter Radar(ISR) ion line plasma line active ionosphere X/O mode

Numerical simulations of FPSO with sloshing tanks in a random freak waves

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Journal of Hydrodynamics 2022年第3期34卷 491-498页

作者： Yuan Zhuang Guo Wang De-cheng Wan jian-wei wu Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design and Research Institute of China Shanghai200011China wuhan Second Ship Design and Research Institute Wuhan430205China

This paper presents a potential-viscous coupled method to simulate a floating production storage and offloading(FPSO)with two liquefied natural gas(LNG)sloshing tanks in a random freak *** potential theory uses high-order-spectral(HOS)*** random wave is generated by HOS for 2000 s,and a freak wave is observed around 1830 *** FPSO LNG model was firstly verified in regular waves using HOS-computational fluid dynamics(CFD)coupled method and validated the HOS-CFD coupled method can solve the ship motion coupled with sloshing tanks *** FPSO with LNG tanks are then simulated in the freak wave,showed the coupling effects when the freak wave *** the existence of the sloshing tanks,the amplitude of the roll motion decreases and the period of roll motion *** breaking phenomenon can be observed when the wave crest of the freak wave encounters with the ship.

关键词： Ship motion with sloshing tank high-order-spectral-computational fluid dynamics(HOS-CFD)method naoe-FOAM-SJTU solver freak waves

Dynamics of k-essence in loop quantum cosmology

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Chinese Physics C 2021年第4期45卷 451-461页

作者： Jiali Shi jian-Pin wu College of Physical Science and Technology Bohai UniversityJinzhou 121013China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

In this paper,we study the dynamics of k-essence in loop quantum cosmology(LQC).The study indicates that the loop quantum gravity(LQG)effect plays a key role only in the early epoch of the universe and is diluted in the later *** fixed points in LQC are basically consistent with those in standard Friedmann-Robertson-Walker(FRW)*** most of the attractor solutions,the stability conditions in L Q C are in agreement with those for the standard FRW *** some special fixed points,however,tighter constraints are imposed thanks to the LQG effect.

关键词： k-essence loop quantum cosmology dynamics of dark energy

Design of task priority model and algorithm for imaging observation problem

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Journal of Systems Engineering and Electronics 2020年第2期31卷 321-334页

作者： wu jian LU Fang ZHANG Jiawei YANG Jinghui XING Lining College of Systems Engineering National University of Defense TechnologyChangsha 410073China College of Logistics and Transportation Central South University of Forestry and TechnologyChangsha 410004China College of Information and Communication National University of Defense TechnologyXi’an 710106China College of Engineering Shanghai Polytechnic UniversityShanghai 201209China

In the imaging observation system, imaging task scheduling is an important topic. Most scholars study the imaging task scheduling from the perspective of static priority, and only a few from the perspective of dynamic priority. However,the priority of the imaging task is dynamic in actual engineering. To supplement the research on imaging observation, this paper proposes the task priority model, dynamic scheduling strategy and Heuristic algorithm. At first, this paper analyzes the relevant theoretical basis of imaging observation, decomposes the task priority into four parts, including target priority, imaging task priority, track, telemetry & control(TT&C)requirement priority and data transmission requirement priority, summarizes the attribute factors that affect the above four types of priority in detail, and designs the corresponding priority model. Then, this paper takes the emergency tasks scheduling problem as the background, proposes the dynamic scheduling strategy and heuristic algorithm. Finally, the task priority model,dynamic scheduling strategy and heuristic algorithm are verified by experiments.

关键词： imaging observation system imaging task priority task priority model dynamic scheduling strategy heuristic algorithm

Research on 3D Distribution of Meandering River Sand Body Using Sedimentary Facies Method and 3D Geological Modeling

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Journal of China University of Mining and Technology 2006年第3期16卷 349-352页

作者： wu jian CAO Dai-yong Key Laboratory of Coal Resources Ministry of Education Beijing 100083 China

Sedimentary facies study is an important method in describing the property and distribution of reservoir. 3D geological modeling is a powerful tool in 3D characterization of geological bodies. By combining the sedimentary facies study with 3D geological modeling to generate 3D sedimentary facies model, the 3D geometry and distribution feature of sand bodies can be more accurately characterized, particularly in 3D view. In Liuchu oilfield of Jizhong depression, the Ed2IV formation was recognized as meandering river deposition facies and five sedimentary facies were identified, which include point bar sand, levee, channel margin, abandoned channel and floodplain. All the 24 sand body facies in Ed2IV were mapped and the 3D sedimentary facies model established based on 2D facies maps. The result shows that the 3D sedimentary facies model is well matched for the research result of sedimentary facies. Being an extension of traditional sedimentary study, the 3D sedimentary facies model can be used to describe the 3D geometry and distribution orders of a single sand body more reliably and more accurately.

关键词： sedimentary facies meandering river 3D model geostatistic simulation

Regional warming induced by urban surface expansion in Shanghai

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Atmospheric and Oceanic Science Letters 2018年第3期11卷 228-235页

作者： ZHAO De-Ming wu jian CAS Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of Sciences Department of Atmospheric Science Yunnan University

To detect the impacts of urban surface expansion on surface air temperature at 2-m（SAT） in Shanghai, China, nested numerical integrations based on satellite-derived urban data between the 1980 s and 2010 s were performed using the Weather Research and Forecasting（WRF） model. Urban surface expansion induced an annual-averaged warming of 0.31 °C from 1980 to 2016 across the whole of Shanghai, showing the greatest intensity between 2010 and 2016. The values were 0.36, 0.78, and 0.75 °C over grids that were classified as urban in both time periods（U2 U）, landuse grids that changed from non-urban to urban（N2 U）, and urban areas（including U2 U and N2 U）, respectively, and revealed weak warming over the inner-ring areas because the urban surfaces had been there since the 1980 s, whereas warming areas were coincident with the outward expansion of the urban surface. Meanwhile, marked seasonal variations could be detected, which were greater in spring and summer but less in autumn and winter. The approximately homogenously distributed SAT maximum（weaker） and heterogeneously SAT minimum（stronger） contributed to the decreased diurnal temperature range. Regional warming induced by urban surface expansion was approximately 0.12 °C per decade, which accounted for 19% of the overall warming across the whole of Shanghai. The values were 0.11 °C per decade and 0.39 °C per decade over U2 U and N2 U, which accounted for approximately 17% and 42% of the overall warming, respectively, and resulted in approximately 41% of the overall warming over urban areas.

关键词： Urban surface expansion surface air temperature regional warming nestedintegration warming trend

Survey on autonomous task scheduling technology for Earth observation satellites

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Journal of Systems Engineering and Electronics 2022年第6期33卷 1176-1189页

作者： wu jian CHEN Yuning HE Yongming XING Lining HU Yangrui College of Systems Engineering National University of Defense TechnologyChangsha 410073China

How to make use of limited onboard resources for complex and heavy space tasks has attracted much *** the continuous improvement on satellite payload capacity and the increasing complexity of observation requirements,the importance of satellite autonomous task scheduling research has gradually *** article first gives the problem description and mathematical model for the satellite autonomous task scheduling and then follows the steps of"satellite autonomous task scheduling,centralized autonomous collaborative task scheduling architecture,distributed autonomous collaborative task scheduling architecture,solution algorithm".Finally,facing the complex and changeable environment situation,this article proposes the future direction of satellite autonomous task scheduling.

关键词： satellite autonomous task scheduling centralized architecture distributed architecture

Evaluating the impacts of land use and land cover changes on surface air temperature using the WRF-mosaic approach

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Atmospheric and Oceanic Science Letters 2018年第3期11卷 262-269页

作者： ZHAO De-Ming wu jian CAs Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of Sciences Department of Atmospheric Science Yunnan University

Satellite-derived land surface data in 1980 and 2010 were used to represent land use and land cover（LULC） changes caused by the rapid economic development and human activities that have occurred over the past few decades in East Asia and China. The effects of LULC changes on the radiation budget and 2-m surface air temperature（SAT） were explored for the period using the Weather Research and Forecasting（WRF） model. The mosaic approach, which considers the N-most abundant land use types within a model grid cell（here, N = 3） and precisely describes the subgridscale LULC changes, was adopted in the integrations. The impacts of LULC changes based on two 36-year integrations showed that SAT generally decreased, with the sole exception being over eastern China, resulting in decreased SAT in China（-0.062 °C） and East Asian land areas（EAL,-0.061 °C）. The LULC changes induced changes in albedo, which influenced the radiation budget. The radiative forcings at the top of the atmosphere were-0.56 W m-2 across the whole of China, and-0.50 W m-2 over EAL. Meanwhile, the altered roughness length mainly influenced near-surface wind speeds, large-scale and upward moisture fluxes, latent heat fluxes, and cloud fractions at different altitudes. Though the impacts caused by the LULC changes were generally smaller at regional scales, the values at local scales were much stronger.

关键词： Land use and land cover change surface airtemperature albedo radiation budget numerical simulation