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Effect of ground cover changes on solar radiation absorption in Three Northeastern Provinces of China

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地球环境学报 2024年第4期15卷 675-690页

作者： SHUAI Yanmin CHEN Yangyang SHAO Congying TIAN Yanjun QU Ge huang jiapeng School of Geomatics Liaoning Technical UniversityFuxin 123000China Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China CAS Research Center for Ecology and Environment of Central Asia Urumqi 830011China College of Geography and Environmental Sciences Zhejiang Normal UniversityJinhua 321004China

Background,aim,and scope Solar radiation is the main source of energy for terrestrial *** changes in the absorption of solar radiation at the ground surface can have a significant impact on the climatic *** and anthropogenic changes in ground cover are important factors affecting the absorption of solar radiation at the ground *** phenomenon is particularly pronounced in the mid and high *** order to quantify the inf luence of surface cover change on the absorption of solar radiation at the surface and to provide a scientific basis for changes in the climatic environment,this paper analyzed ground cover change,ground absorbed solar radiation change and the effect of ground cover change on ground absorbed solar radiation in the Three Northeastern Provinces of China from 2001 to *** and methods In this study,the Three Northeastern Provinces of China were used as the study ***,satellite remote sensing data were used to obtain land cover data and albedo data for Aug.1st of each year in 2001,2005,2010,2015 and *** albedo data were further used to calculate the absorbed solar radiation data at the ground ***,the land cover data were used to count the area changes and shifts of different land classes over the five-year *** land cover data were overlaid with the surface absorbed solar radiation data to obtain the mean and standard deviation of radiation absorption for different ground *** surface absorbed solar radiation data were subtracted to obtain the changes in surface absorbed solar radiation for 2001-2005,2005-2010,2010-2015 and ***,we used a combination of shifted changes in ground classes and changes in surface absorbed solar radiation data,with unchanged ground classes as a baseline and data such as slope orientation as an *** analyzed the effect of ground cover change on surface absorbed solar radiation at regional and pixel point ***(1)T

关键词： land surface cover changes surface absorption of solar radiation the Three Northeastern Provinces albedo

ICESat-2激光雷达噪声光子标识及分布特点研究

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测绘与空间地理信息 2024年第3期47卷 21-24页

作者：黄佳鹏宇洋辽宁工程技术大学测绘与地理科学学院辽宁阜新123000

利用PhotonLabeler实现对星载光子计数数据的噪声光子标识研究,并分析常见场景噪声光子分布特点,最后生成了一套光子计数噪声标识产品。本研究结果包括:太阳辐射会引起大量噪声出现;海洋区域的噪声光子会受到风浪、水深、海岸线、水中... 详细信息

利用PhotonLabeler实现对星载光子计数数据的噪声光子标识研究,并分析常见场景噪声光子分布特点,最后生成了一套光子计数噪声标识产品。本研究结果包括:太阳辐射会引起大量噪声出现;海洋区域的噪声光子会受到风浪、水深、海岸线、水中杂质等因素的影响;冰川情况下光子分布多受到积雪厚度、积雪密度、冰盖厚度、冰盖密集度及冰盖表面的粗糙程度等一些外来因素的影响;冬季情况下,噪声光子数目明显少于夏季,分析得出冠层高度及植被覆盖率等因素会引起大量噪声光子出现;多数情况下,弱光束对地表反演能力低于强光束,强光束可以捕获更多的光子点云数据。

关键词： ICESat-2 ATL03 噪声光子标识 PhotonLabeler

An Improved Extreme Learning Machine Prediction Model for Ionospheric Total Electron Content

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Journal of Geodesy and Geoinformation Science 2023年第1期6卷 1-10页

作者： Jianmin WANG jiapeng huang School of Geomatics Liaoning Technical UniversityFuxin 123000China

Earth’s ionosphere is an important medium for navigation,communication,and radio wave *** Electron Content(TEC)is a descriptive quantify for ionospheric ***,the traditional empirical model could not fully consider the changes of TEC time series,the prediction accuracy level of TEC data performed not *** this study,an improved Extreme Learning Machine(ELM)model is proposed for ionospheric TEC *** involved the use of Empirical Mode Decomposition(EMD)and a Fuzzy C-Means(FCM)clustering algorithm to pre-process data used as input to the ELM *** proposed model fully uses the TEC data characteristics and expected to perform better prediction *** measurements provided by the Centre for Orbit Determination in Europe(CODE)were used to evaluate the performance of the improved ELM model in terms of prediction accuracy,applicable latitude,and the number of required training *** results produced a Mean Relative Error(MRE)and a Root Mean Square Error(RMSE)of 8.5%and 1.39 TECU,respectively,outperforming the ELM algorithm(RMSE=2.33 TECU and MRE=17.1%).The improved ELM model exhibited particularly high prediction accuracy in mid-latitude regions,with a mean relative error of 7.6%.This value improved further as the number of available training data increased and when 20-doys data were trained,achieving a mean relative error of 4.9%.These results suggest the proposed model offers higher prediction accuracy than conventional algorithms.

关键词： ELM model EMD FCM incentive function ionospheric TEC prediction

Broadband mid-infrared supercontinuum generation in dispersion-engineered As_(2)S_(3)-silica nanospike waveguides pumped by 2.8 μm femtosecond laser

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Photonics Research 2021年第4期9卷 630-636页

作者： Pan Wang jiapeng huang Shangran Xie Johann Troles and Philip St.J.Russell Max Planck Institute for the Science of Light 91058 ErlangenGermany Universitéde Rennes I Sciences Chimiques de Rennes35042 RennesFrance Friedrich-Alexander-Universität 91058 ErlangenGermany

Broadband mid-infrared(IR)supercontinuum laser sources are essential for spectroscopy in the molecular fingerprint ***,we report generation of octave-spanning and coherent mid-IR supercontinua in As_(2)S_(3)-silica nanospike hybrid waveguides pumped by a custom-built 2.8μm femtosecond fiber *** waveguides are formed by pressure-assisted melt-filling of molten As_(2)S_(3) into silica capillaries,allowing the dispersion and nonlinearity to be precisely *** coherent spectra spanning from 1.1μm to 4.8μm(30 dB level)are observed when the waveguide is designed so that 2.8μm lies in the anomalous dispersion ***,linearly tapered millimeter-scale As_(2)S_(3)-silica waveguides are fabricated and investigated for the first time,to the best of our knowledge,showing much broader supercontinua than uniform waveguides,with improved spectral *** waveguides are demonstrated to be long-term stable and water-resistant due to the shielding of the As_(2)S_(3) by the fused silica *** offer an alternative route to generating broadband mid-IR supercontinua,with applications in frequency metrology and molecular spectroscopy,especially in humid and aqueous environments.

关键词： pumped millimeter waveguide

利用VMD-SSA-LSTM的电离层总电子含量预报研究

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导航定位学报 2024年第3期12卷 88-101页

作者：王建敏刘志鹏黄佳鹏徐迟孟祥妹赵振东辽宁工程技术大学测绘与地理科学学院辽宁阜新123000 黑龙江林业职业技术学院城市建设系黑龙江牡丹江157000

针对太阳活动影响下机器学习模型对电离层总电子含量(TEC)短期预报精度不高的问题,本文提出了一种基于变分模态分解(VMD)、麻雀搜索算法(SSA)、长短期记忆神经网络(LSTM)的组合模型(VMD-SSA-LSTM),以期提高TEC短期预报精度。利用VMD算... 详细信息

针对太阳活动影响下机器学习模型对电离层总电子含量(TEC)短期预报精度不高的问题,本文提出了一种基于变分模态分解(VMD)、麻雀搜索算法(SSA)、长短期记忆神经网络(LSTM)的组合模型(VMD-SSA-LSTM),以期提高TEC短期预报精度。利用VMD算法对不同时期太阳活动程度影响下的东、西半球TEC格网点数据分解,利用SSA优化LSTM模型,将分解的TEC样本分量及模型最优初始权值和阈值输入到LSTM模型中,将分量预测序列合并重构,得到电离层TEC预测值。实验表明:VMD-SSA-LSTM组合模型在东、西半球太阳活动强烈、适中、较弱时期的均方根误差分别为0.77、0.56、0.69;0.92、0.76、0.73个TECu,平均绝对误差平均值分别为0.69、0.47、0.56;0.79、0.65、0.58个TECu,平均相对精度分别达到94%、94%、93%;93%、91%、91%以上,残差绝对值分布在0~1个TECu的比例均值分别为75.56%、96.11%、85%;74.44%、80.55%、78.33%,较VMD-LSTM、LSTM两种模型预报精度有显著提升。

关键词：太阳活动电离层总电子含量变分模态分解麻雀优化算法长短期记忆神经网络

基于多场耦合的无线电侦扰一体主机散热特性分析

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航天器环境工程 2024年第3期41卷 325-335页

作者：刘艳欣朱乐乐沈华明杨建江黄家鹏任欣悦上海航天电子技术研究所上海201108

针对无线电侦扰一体主机因高度集成引起的高热流密度导致散热难的问题,通过分析整机的散热路径,构建传热网络图;应用传热学和流体力学理论,建立主机热−流−固耦合散热数学模型;基于ANSYS Icepak仿真平台,构建主机的三维全尺寸数值模型研... 详细信息

针对无线电侦扰一体主机因高度集成引起的高热流密度导致散热难的问题,通过分析整机的散热路径,构建传热网络图;应用传热学和流体力学理论,建立主机热−流−固耦合散热数学模型;基于ANSYS Icepak仿真平台,构建主机的三维全尺寸数值模型研究其散热特性。结果表明:当风扇风量约为56 m^(3)/h时,无线电侦扰一体主机的散热性能较好且噪声较小;当电源箱的热源同侧分布,侦扰箱和导航诱骗箱的热源异侧分布,且热源靠近进风口或出风口时,主机的散热性能好且效率高;当支架孔隙和设备间距分别为15 mm和10 mm时,主机的散热性能较好且结构强度高,同时主机质量和体积均较小;当散热器翅片的高度、厚度和间距分别为7.5 mm、1 mm和5 mm时,强化散热效果较好且主机质量小。

关键词：侦扰一体主机传热学理论散热数学模型热−流−固耦合散热特性

基于图控分离和2次分类的无人机信号识别方法

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上海大学学报（自然科学版） 2024年第3期30卷 435-450页

作者：王安平吕振彬扆梓轩沈华明黄家鹏陆文斌上海大学通信与信息工程学院上海200444 上海航天电子通讯设备研究所创新研究室上海201109

无人机(unmanned aerial vehicle, UAV)行业的快速发展给重要场所的低空空域带来安全隐患.为了对无人机实施有效管制,研制一套能够识别无人机信号的无线电侦测系统有重要意义.针对相似无人机之间识别困难的问题,提出了一种基于图控分离... 详细信息

无人机(unmanned aerial vehicle, UAV)行业的快速发展给重要场所的低空空域带来安全隐患.为了对无人机实施有效管制,研制一套能够识别无人机信号的无线电侦测系统有重要意义.针对相似无人机之间识别困难的问题,提出了一种基于图控分离和2次分类的无人机信号识别方法.该方法基于无人机图像传输信号(image transmission signal, ITS)的循环特性提取其时域参数,采用分类决策树对无人机进行初步分类识别;再通过分离无人机的图像传输信号与飞行控制信号(flight control signal, FCS)的方式分别提取其时频特征参数;最后进行了2次分类识别.实验结果表明,对于6种常见无人机的通信信号,在信噪比(signal-to-noise ratio, SNR)为0 d B时平均识别准确率可达97.4%,说明该方法可以精确识别无人机.

关键词：无线电侦测正交频分复用分段快速傅里叶变换(fast Fourier transform,FFT) 时频分析特征提取

军人心理资本在职业倦怠和军队士气的中介作用研究

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联勤军事医学 2024年第6期38卷 511-515页

作者：王雯赵富花张正华黄嘉鹏张罗鹏 95861部队保障部医院内科甘肃酒泉735018 95861部队保障部医院卫勤战救处甘肃酒泉735018 95861部队保障部医院综合保障大队甘肃酒泉735018

目的研究军人心理资本在军人职业倦怠和军队士气的中介作用,探索提升军队士气的方法,为提高军队战斗力提供参考。方法对西北某部军人采用整群抽样的方法,进行问卷调查,包括社会人口学资料、心理资本量表(psychological capital questi... 详细信息

目的研究军人心理资本在军人职业倦怠和军队士气的中介作用,探索提升军队士气的方法,为提高军队战斗力提供参考。方法对西北某部军人采用整群抽样的方法,进行问卷调查,包括社会人口学资料、心理资本量表(psychological capital questionnaire, PCQ)、军人职业倦怠量表(military burnout scale, MJBS)及军队士气量表,共发放问卷400份,回收有效问卷394份。应用SPSS 23.0软件对所得数据进行描述性统计分析、Pearson相关性分析及方差分析,采用逐步回归分析检验PCQ对军人MJBS及军队士气量表评分的中介效应,并用Bootstrap法进行验证。结果军人PCQ、MJBS及军队士气量表评分的人口学资料的单因素分析结果显示,军人PCQ评分在不同性别、民族及学历间差异均有统计学意义(P均0.05)。MJBS与军队士气量表评分呈显著负相关(r=-0.354,P<0.01),与PCQ呈显著负相关(r=-0.159,P<0.01);PCQ与军队士气量表评分呈显著正相关(r=0.514,P<0.01),并且在军人MJBS与军队士气量表评分间起部分中介效应,中介效应占总效应的21.02%(-0.115/-0.547)。结论军人职业倦怠不仅直接影响军队士气,而且通过心理资本影响军队士气,良好的心理资本可以减少军人职业倦怠的产生,有助于提升军队士气。

关键词：心理资本量表军人职业倦怠量表军队士气量表中介作用战斗力

Tuning the solubility of polysulfides for constructing practical lithium-sulfur battery

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Journal of Energy Chemistry 2024年第8期95卷 611-617,I0013页

作者： jiapeng Li Jianlong Cong Haijin Ji Ting Shi Lixia Yuan Yunhui huang State Key Laboratory of Material Processing and Die&Mold Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina

Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low ***,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li *** get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_*** introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode *** minor Se substitution compensates the decrease in kinetic due to the decreased solubility of *** this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,***,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode *** makes more sense to guide the electrolyte design for practical Li-S batteries.

关键词： Li-S batteries Lithium polysulfides Solubility Shuttle effect Interface Se doping