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Retrieval of high spatial resolution mountainous land surface temperature considering topographic and adjacency effects

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Science China Earth Sciences 2024年第11期67卷 3610-3625页

作者： zhiwei he Bohui TANG Zhaoliang LI Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Plateau Remote Sensing Department of Education of Yunnan ProvinceKunming 650093China State Key Lab of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Key Laboratory of Agricultural Remote Sensing Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China

Land surface temperature(LST) is a key parameter reflecting the interaction between land and atmosphere. Currently,thermal infrared(TIR) quantitative remote sensing technology is the only means to obtain large-scale, high spatial resolution LST. Accurately retrieving high spatial resolution mountainous LST(MLST) plays an important role in the study of mountain climate change. The complex terrain and strong spatial heterogeneity in mountainous areas change the geometric relationship between the surface and satellite sensors, affecting the radiation received by the sensors, and rendering the assumption of planar parallelism invalid. In this study, considering the influence of complex terrain in mountainous areas on atmospheric downward radiation and the thermal radiation contribution of adjacent pixels, a mountainous TIR radiative transfer model based on the sky view factor was developed. Combining with the atmospheric radiative transfer model MODTRAN 5.2, a nonlinear generalized split-window algorithm suitable for high spatial resolution MLST retrieval was constructed and applied to Landsat-9 TIRS-2satellite TIR remote sensing data. The analysis results indicate that neglecting the topographic and adjacency effects would lead to significant discrepancies in LST retrieval, with simulated data showing LST differences of up to 2.5 K. Furthermore, due to the lack of measured MLST in the field, the MLST accuracy obtained by this retrieval method was indirectly validated using the currently recognized highest-accuracy forward 3D radiative transfer model DART. The MLST and emissivity were input into the DART model to simulate the brightness temperature at the top of the atmosphere(TOA) of Landsat-9 band 10, and compared with the brightness temperature at TOA of Landsat-9 band 10. The RMSE(Root Mean Square Error) for the two subregions was0.50 and 0.61 K, respectively, indicating that the method proposed can retrieve high-precision MLST.

关键词： Mountainous land surface temperature Topographic and adjacency effects Nonlinear generalized split-window algorithm Landsat-9 data DART model

The Contribution of Mesoscale Convective Systems to Intense Hourly Precipitation Events during the Warm Seasons over Central East China

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Advances in Atmospheric Sciences 2016年第11期33卷 1233-1239页

作者： zhiwei he Qinghong ZHANG Jun SUN Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking University National Meteorological Center China Meteorological Administration

Central East China is an area where both intense hourly precipitation（IHP） events and mesoscale convection systems（MCSs） occur frequently in the warm seasons. Based on mosaics of composite Doppler radar reflectivity and hourly precipitation data during the warm seasons（May to September） from 1 July 2007 to 30 June 2011, the contribution of MCSs to IHP events exceeding 20 mm h^-1 over central East China was evaluated. An MCS was defined as a continuous or quasicontinuous band of 40d BZ reflectivity that extended for at least 100 km in at least one direction and lasted for at least 3h. It was found that the contribution of MCSs to IHP events was 45% on average over central East China. The largest contribution,more than 80%, was observed along the lower reaches of the Yellow River and in the Yangtze River–Huaihe River *** regions were the source regions of MCSs, or along the frequent tracks of MCSs. There were two daily peaks in the numbers of IHP events： one in the late afternoon and one in the early morning. These peaks were more pronounced in July than in other months. MCSs contributed more to the early-morning IHP event peaks than to the late-afternoon peaks. The contributions of MCSs to IHP events with different intensities exhibited no significant difference, which fluctuated around 50% on average over central East China.

关键词： afternoon morning reflectivity Precipitation contributions Yangtze convection mesoscale Events exceeding

Nonlinear spectral-like schemes for hybrid schemes

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Science China(Physics,Mechanics & Astronomy) 2014年第4期57卷 753-763页

作者： he zhiwei LI XinLiang LIANG Xian China North Vehicle Research Institute State Key Laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences

In spectral-like resolution-WENO hybrid schemes,if the switch function takes more grid points as discontinuity points,the WENO scheme is often turned on,and the numerical solutions may be too ***,if the switch function takes less grid points as discontinuity points,the hybrid schemes usually are found to produce oscillatory solutions or just to be *** if the switch function takes less grid points as discontinuity points,the final hybrid scheme is inclined to be more stable,provided the spectral-like resolution scheme in the hybrid scheme has moderate shock-capturing *** this idea,we propose nonlinear spectral-like schemes named weighted group velocity control(WGVC)*** schemes show not only high-resolution for short waves but also moderate shock capturing *** a new class of hybrid schemes is designed in which the WGVC scheme is used in smooth regions and the WENO scheme is used to capture *** hybrid schemes show good resolution for small-scales structures and fine shock-capturing capabilities while the switch function takes less grid points as discontinuity *** seven-order WGVC-WENO scheme has also been applied successfully to the direct numerical simulation of oblique shock wave-turbulent boundary layer interaction.

关键词： group velocity control hybrid WENO shockwave-turbulent boundary layer interaction direct numerical simulation

甲酸铵含量对现场混装乳胶基质流变及热分解性能的影响

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高压物理学报 2025年第1期39卷 53-63页

作者：何志伟岳嘉伟黄振祎胡前浩周圣涛安徽理工大学化工与爆破学院安徽淮南232001

为提高现场混装乳化炸药的耐高温性能,制备了4种不同甲酸铵含量的现场混装乳化炸药基质样品。采用旋转流变仪和同步热分析仪研究了4种样品的流动性、黏弹性、黏温及其热分解性能。结果表明:加入甲酸铵可以提高现场混装乳胶基质的黏度,... 详细信息

为提高现场混装乳化炸药的耐高温性能,制备了4种不同甲酸铵含量的现场混装乳化炸药基质样品。采用旋转流变仪和同步热分析仪研究了4种样品的流动性、黏弹性、黏温及其热分解性能。结果表明:加入甲酸铵可以提高现场混装乳胶基质的黏度,且随着甲酸铵质量分数的增加,样品的黏度出现先增大后减小的趋势;与未添加甲酸铵的样品相比,加入甲酸铵的样品的弹性模量增大,稳定性增强;当甲酸铵的质量分数不大于9%时,在50℃左右的温度下,乳胶基质的黏度均能够满足泵送要求;甲酸铵的加入对乳胶基质的热分解过程没有明显影响;随着甲酸铵质量分数的增加,其外推起始分解温度、活化能、热爆炸临界温度和自加速分解温度均有所增加,现场混装乳胶基质的热稳定性和热安全性得到提升。

关键词：现场混装乳化炸药基质甲酸铵流变性能热分解性能

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A 5th order monotonicity-preserving upwind compact difference scheme

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Science China(Physics,Mechanics & Astronomy) 2011年第3期54卷 511-522页

作者： he zhiwei LI XinLiang FU DeXun MA YanWen The Key Laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China The State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

Based on an upwind compact difference scheme and the idea of monotonicity-preserving, a 5th order monotonicity-preserving upwind compact difference scheme （m-UCD5） is proposed. The new difference scheme not only retains the advantage of good resolution of high wave number but also avoids the Gibbs phenomenon of the original upwind compact difference scheme. Compared with the classical 5th order WENO difference scheme, the new difference scheme is simpler and small in diffusion and computation load. By employing the component-wise and characteristic-wise methods, two forms of the new difference scheme are proposed to solve the N-S/Euler equation. Through the Sod problem, the Shu-Osher problem and tbe two-dimensional Double Mach Reflection problem, numerical solutions have demonstrated this new scheme does have a good resolution of high wave number and a robust ability of capturing shock waves, leading to a conclusion that the new difference scheme may be used to simulate complex flows containing shock waves.

关键词： upwind compact scheme monotonicity-preserving compressible flows shock capturing scheme

Constructing backbone network by using tinker algorithm

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Frontiers of physics 2017年第6期12卷 63-77页

作者： zhiwei he Meng Zhan Jianxiong Wang Chenggui Yao Department of Mathematics Shaoxing University Shaoxing 312000 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China College of Science Hubei University of Technology Wuhan 430068 China

Revealing how a biological network is organized to realize its function is one of the main topics in systems biology. Tile functional backbone network, defined as the primary structure of the biological network, is of great importance in maintaining the main function of the biological network. We propose a new algorithm, the tinker algorithm, to determine this core structure and apply it in the cell-cycle system. With this algorithm, the backbone network of the cell-cycle network can be determined accurately and efficiently in various models such as the Boolean model, stochastic model, and ordinary differential equation model. Results show that our algorithm is more efficient than that used in the previous research. We hope this method can be put into practical use in relevant future studies.

关键词： biological network backbone network tinker algorithm mathematical model

Optimal configuration for vibration frequencies in a ring of harmonic oscillators： The nonidentical mass effect

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Frontiers of physics 2015年第3期10卷 89-100页

作者： Shuai Liu Guo-Yong Zhang zhiwei he Meng Zhan College of Science Northwest A&F University Yangling 712100 China Wuhan Center for Magnetic Resonance State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 China College of Computer Science and Technology Hubei Normal University Huangshi 435002 China University of the Chinese Academy of Sciences Beijing 100049 China

The parameter diversity effect in coupled nonidentical elements has attracted persistent interest in nonlinear dynamics. Of fundamental importance is the so-called optimal configuration problem for how the spatial position of elements with different parameters precisely determines the dynamics of the whole system. In this work, we study the optimal configuration problem for the vibration spectra in the classical mass-spring model with a ring configuration, paying particular attention to how the configuration of different masses affects the second smallest vibration frequency （ω2） and the largest one （ωN）. For the extreme values of ω2 and ωN, namely, （ω2）min, （ω2）max, （ωN）min, and （ωN）max, we find some explicit organization rules for the optimal configurations and some approximation rules when the explicit organization rules are not available. The different distributions of ω2 and ωN are compared. These findings are interesting and valuable for uncovering the underlying mechanism of the parameter diversity effect in more general cases.

关键词： synchronization vibration frequencies normal modes complex systems

Enhanced vibrational resonance in a single neuron with chemical autapse for signal detection

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Chinese Physics B 2020年第12期29卷 556-563页

作者： zhiwei he Chenggui Yao Jianwei Shuai Tadashi Nakano Department of Mathematics Shaoxing UniversityShaoxing 312000China College of Mathematics Physics and Information EngineeringJiaxing UniversityJiaxing 314000China Department of Physics State Key Laboratory of Cellular Stress BiologyInnovation Center for Cell Signaling NetworkXiamen UniversityXiamen 361102China Graduate School of Frontier Biosciences Osaka University5408570Japan

Many animals can detect the multi-frequency signals from their external *** understanding for underlying mechanism of signal detection can apply the theory of vibrational resonance,in which the moderate high frequency driving can maximize the nonlinear system's response to the low frequency subthreshold *** this work,we study the roles of chemical autapse on the vibrational resonance in a single neuron for signal *** reveal that the vibrational resonance is strengthened significantly by the inhibitory autapse in the neuron,while it is weakened typically by the excitatory *** is generally believed that the inhibitory synapse has a suppressive effect in neuronal ***,we find that the detection of the neuron to the low frequency subthreshold signal can be improved greatly by the inhibitory *** finding indicates that the inhibitory synapse may act constructively on the detection of weak signal in the brain and neuronal system.

关键词： neuronal dynamics autapse vibrational resonance synchronization time delay

Time-series variation and attribution analysis of downward shortwave radiation over the Yunnan-Kweichow plateau from 1984 to 2018

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International Journal of Digital Earth 2023年第1期16卷 337-354页

作者： Lijia Cheng Bo-Hui Tang zhiwei he Zhitao Fu Menghua Li Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunmingPeople’s Republic of China State Key Laboratory of Resources and Environment Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China

The downward shortwave radiation(DSR)is a key input parameter for land surface models and climate *** on the daily averaged Global Land Surface Satellite downward shortwave radiation(GLASS-DSR)dataset over the Yunnan-Kweichow Plateau(YKP)from 1984 to 2018,this paper analyzes variation trend and breakpoints of *** results show that:annual averaged DSR decreases at a decreasing rate of-1.84 W·m^(-2)·decade^(-1) over the YKP from 1984 to 2018;the overall distribution of interannual averaged DSR shows higher in the mid-west,and gradually decreasing from west to northeast over the YKP;the estimated averaged DSR is larger in spring than in summer due to the influence of the monsoon;monthly averaged DSR reaches its maximum in May and its minimum in December;breakpoints are found in the seasonal and trend components of daily averaged *** driving factors are examined for their effects on DSR variation,including annual average temperature,precipitation,10 m wind speed,aerosol optical thickness(AOT),total cloud cover,elevation,slope,aspect,longitude,latitude,and climate *** to thefindings,AOT predominates in the spatio-temporal distribution of DSR over the *** study will contribute to studies related to climate change and highland radiation.

关键词： Yunnan-Kweichow plateau downward shortwave radiation time-series analysis breakpoints detection attribution analysis