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Redevelopment of liftoff rates of saltating sand grains based on a simple optimization model

Science China Earth Sciences 2010年第4期53卷 568-574页

作者： CHENG Hong & ZOU XueYong State Key Laboratory of Earth Surface Processes and Resource Ecology,beijing normal university,beijing 100875,China {2.,beijing normal university,beijing 100875,China Key Laboratory of Environmental Change and Natural Disaster of the Ministry of Education of China,beijing normal university,beijing 100875,China 1. State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Beijing 100875 China2. MOE Engineering Center of Desertification and Blown-sand Control Beijing Normal University Beijing 100875 China3. Key Laboratory of Environmental Change and Natural Disaster of the Ministry of Education of China Beijing Normal University Beijing 100875 China

This paper is a redevelopment result of liftoff rates of saltating sand grains based on our previous *** sand flow is a complex multi-phase flow because of a special two-phase gas-solid flow near ground *** extensive research on the movement of blowing sand,no model fully characterizes aeolian sand flow,and large differences often exist between simulations of aeolian sand movement and field *** key problem is a few of sufficient research on liftoff rates of saltating sand grains(also called the number of liftoff sand grains per unit time and per unit bed area).It is necessary to re-search in advance liftoff rates of saltating sand *** redeveloped liftoff rates of saltating sand grains by establishing an optimization model based on the flux of aeolian sand flow at different heights of the sampler in wind tunnel and the simulated capture of saltating sand grains by different heights of the sampler that are from different liftoff position(distance from the sampler) in order to revise previous inversion condition of liftoff rates of saltating sand *** rates increased rapidly with increasing wind *** frictional wind velocities of u=0.67,0.77,0.82.0.83,and 0.87 m s-1,liftoff rates were 3840,954502.52.5114,5499407,and 76962.1 sand grain s-1 m-2.*** rates could be expressed as the square of the instantaneous frictional wind velocity and a constant(0.663) that differs from the critical(threshold) frictional wind velocity at which saltation *** our results require additional experimental validation and the simple optimization model must be improved,they nonetheless provide a strong basis for future research.

关键词： liftoff rates of saltating sand grains optimization model wind tunnel two-phase gas-solid flow

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Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

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Science China(Physics,Mechanics & Astronomy) 2005年第6期48卷 706-715页

作者： ZHANG Jingfu1, XIE Jingyi2. WANG Chuan1, DENG Zhiwei3, LU Zhiheng4, & LONG Guilu1,5 1. Key Laboratory For Quantum Information and Measurements of moe, Department of Physics, Tsinghua university, {2. 100084,China 2. Department of Materials Science and {2., beijing normal university, beijing 100875, China 3. Testing and Analytical center, beijing normal university, beijing 100875,China 4. Department of Physics, beijing normal university, beijing 100875, China 5. Key Laboratory For atomic and Molecular Nanosciences, Tsinghua university, {2. 100084,China 1. Key Laboratory For Quantum Information and Measurements of moe Department of Physics Tsinghua University 100084 Beijing China 2. Department of Materials science and engineering Beijing Normal University 100875 Beijing China 3. Testing and Analytical center Beijing Normal University 100875 Beijing China 4. Department of Physics Beijing Normal University 100875 Beijing China 5. Key Laboratory For Atomic and Molecular Nanosciences Tsinghua University 100084 Beijing China

A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2.+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

关键词： quantum dense coding, multiple round, nuclear magnetic resorance

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Multiparty quantum secret sharing of classical and quantum messages

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Progress in Natural Science:Materials International 2007年第1期17卷 26-31页

作者： CHEN Pan, DENG Fuguo and LONG Guilu ( Key Laboratory for Quantum Information and Measurements, and Department of Physics, Tsinghua university, beijing 100084, China Key Laboratory of Beam Technology and Material Modification, {2., Institute of Low Energy Nuclear Physics, and Department of Material Science and {2., beijing normal university, beijing 100875, China beijing Radiation center, beijing 100875, China Key Laboratory for Atomic and Molecular Nano-Sciences, Tsinghua university, beijing 100084, China) [a]Key Laboratory for Quantum Information and Measurements and Department of Physics Tsinghua University Beijing China [b]Key Laboratory of Beam Technology and Material Modification MOE Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing China [c]beijing Radiation center Beijing China [d]Key Laboratory for Atomic and Molecular Nano-Sciences Tsinghua University Beijing China

A scheme for multiparty quantum secret sharing of classical and quantum messages is proposed by using entanglement swapping. This scheme can distribute not only the classical information but also the quantum informati... 详细信息

关键词： quantum secret sharing classical message quantum message EPR pair.

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基于遥感信息和WOFOST模型参数同化的冬小麦单产估算方法研究

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麦类作物学报 2018年第9期38卷 1127-1136页

作者：陈艳玲顾晓鹤宫阿都胡圣武北京师范大学环境遥感与数字城市北京市重点实验室北京100875 北京师范大学环境演变与自然灾害教育部重点实验室北京100875 北京师范大学地理科学学部北京100875 国家农业信息化工程技术研究中心北京100097 河南理工大学测绘与国土信息工程学院河南焦作454000

为探讨遥感信息和作物生长模型在作物估产方面的优势互补特性,选取河北省藁城市冬小麦作为研究对象,采集多个关键生育时期的生理生化、农田环境、气象等数据,并获取准同步的环境减灾小卫星HJ-CCD影像数据,采用植被指数反演冬小麦叶面积... 详细信息

为探讨遥感信息和作物生长模型在作物估产方面的优势互补特性,选取河北省藁城市冬小麦作为研究对象,采集多个关键生育时期的生理生化、农田环境、气象等数据,并获取准同步的环境减灾小卫星HJ-CCD影像数据,采用植被指数反演冬小麦叶面积指数(LAI),基于扩展傅里叶振幅灵敏度检验法(EFAST)对WOFOST作物模型的2.个初始参数进行全局敏感性分析,筛选敏感性参数,调整WOFOST模型的核心参数,利用查找表优化算法构建基于WOFOST模型和遥感LAI数据同化的区域尺度冬小麦单产预测模型,并定量预测区域冬小麦单产水平。结果表明,增强型植被指数(EVI)是遥感反演LAI的最佳植被指数(开花期建模r^2.0.913,RMSE=0.410,灌浆期建模r^2.0.798,RMSE=0.470),预测能力最强(开花期r^2.0.858,RMSE=0.531,灌浆期r2.0.861,RMSE=0.42.);筛选出6个待优化参数,即TSUM1、SLATB1、SLATB2.SPAN、EFFTB3和TMPF4;产量预测精度r^2.0.914,RMSE=2.3.67kg·hm^(-2.,找到了待优化参数的最佳取值,最终完成了单产模拟。

关键词：冬小麦估产叶面积指数 WOFOST模型同化

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