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数字经济发展如何影响城市碳排放?——来自中国283个地级市的经验数据

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生态经济 2024年第2期40卷 39-51页

作者：曹建飞韩延玲刘慧龙新疆财经大学统计与数据科学学院新疆乌鲁木齐830012 中国人民银行乌鲁木齐中心支行新疆乌鲁木齐830012

为探讨数字经济对城市碳排放的影响,基于2011—2020年中国283个地级以上城市的面板数据,构建综合评价指标体系测算数字经济指数,核算各城市碳排放量,采用SBM模型测算城市碳排放效率,并以产业结构高级化和合理化指数来刻画城市的产业结... 详细信息

为探讨数字经济对城市碳排放的影响,基于2011—2020年中国283个地级以上城市的面板数据,构建综合评价指标体系测算数字经济指数,核算各城市碳排放量,采用SBM模型测算城市碳排放效率,并以产业结构高级化和合理化指数来刻画城市的产业结构升级,在此基础上进行计量分析。结果发现:数字经济发展能够提升碳排放效率,二者呈现出“U”型关系,数字经济发展能够降低碳排放强度和减少碳排放量,均呈现出倒“U”型关系;数字经济能够通过技术创新或产业结构升级影响碳排放,且技术创新和产业结构升级在数字经济与碳排放之间存在链式中介效应;数字经济、技术创新和产业结构升级对城市碳排放存在门槛效应,数字经济和技术创新在门槛值前后对碳排放效率的影响均呈现“先抑后扬”,对碳排放量的影响为“先扬后抑”,对碳排放强度跨越门槛后有显著的抑制作用,产业结构高级化和合理化指数跨越门槛值后能够提高碳排放效率、减少碳排放量,但对碳排放强度不产生影响。最后,基于实证结论提出了相应的政策建议。

关键词：数字经济碳排放面板门槛回归链式中介效应

基于机器学习模型FY⁃3D MWRI海面风速反演

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上海航天（中英文） 2024年第4期41卷 120-132,172页

作者：张云韩天辉孟婉婷杨树瑚周绍辉韩彦岭上海海洋大学信息学院上海201306 上海市海洋智能信息与导航遥感工程技术研究中心上海201306 上海航天电子技术研究所上海201109 上海航天空间技术有限公司上海201109

风云三号D星(FY-3D)微波成像仪(MWRI)L1级亮温数据可用于全球海面风速反演,本文讨论了在晴空区和云区使用多元线性统计回归模型和机器学习模型反演海面风速的情况,在晴空区将4 d测试集分别放入多元线性统计回归模型,采用随机森林(RF),... 详细信息

风云三号D星(FY-3D)微波成像仪(MWRI)L1级亮温数据可用于全球海面风速反演,本文讨论了在晴空区和云区使用多元线性统计回归模型和机器学习模型反演海面风速的情况,在晴空区将4 d测试集分别放入多元线性统计回归模型,采用随机森林(RF),支持向量回归(SVR),卷积神经网络(CNN)和Stacking融合(SF)模型对海面风速进行反演,最优的均方根误差(RMSE)分别为1.56、1.31、1.24、1.29和1.27 m/s;在云区2 d测试集上的最优RMSE分别为2.12、1.98、1.87、1.89和1.89 m/s。为了进一步验证晴空区海面风速反演的可靠性,选取美国国家浮标数据中心(NDBC)实测的浮标风速对海面反演风速进行验证,CNN反演风速与NDBC实测风速的RMSE为0.74 m/s,决定系数(R2)为0.80;SF反演风速与NDBC实测风速的RMSE为0.85 m/s,R2为0.74。结果证实了通过机器学习模型能够很好地完成FY-3D MWRI亮温反演全球海面风速的任务。

关键词：风云三号D星(FY-3D) 微波成像仪(MWRI) 海面风速反演机器学习 Stacking融合(SF)模型

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星载GNSS-R检测太湖水华可行性分析

北京航空航天大学学报 2024年第3期50卷 695-705页

作者：张云王雨周绍辉孟婉婷韩彦岭杨树瑚上海海洋大学信息学院上海201306 上海海洋智能信息与导航遥感工程技术研究中心上海201306 上海航天空间技术有限公司上海201109 上海航天电子技术研究所上海201109

星载全球导航卫星系统反射信号(GNSS-R)属于被动遥感技术,具有数据重访周期高、全天时、全天候、信号源丰富等优势。基于此,研究星载GNSS-R检测太湖水华的可行性。星载GNSS-R可以有效检测反射面的粗糙程度,通过使用相干反射表征反射面... 详细信息

星载全球导航卫星系统反射信号(GNSS-R)属于被动遥感技术,具有数据重访周期高、全天时、全天候、信号源丰富等优势。基于此,研究星载GNSS-R检测太湖水华的可行性。星载GNSS-R可以有效检测反射面的粗糙程度,通过使用相干反射表征反射面的粗糙度,研究不同风速区间内相干反射与蓝藻水华的关系。利用2020年4—8月美国气旋全球导航卫星系统(CYGNSS)数据,计算CYGNSS镜面反射点的时延多普勒图(DDM)功率比。以“哨兵-3”卫星水色遥感仪器(OLCI)影像最大特征峰高度(MPH)算法反演出的太湖叶绿素浓度作为参照,与欧洲中期天气预报中心(ECMWF)的风速产品进行时空间线性匹配,分析发现,在1~2.5 m/s风速区间内,叶绿素浓度达到0.1 mg/L以上时,极易引起镜面反射点发生相干反射,且功率比与叶绿素浓度的相关系数为0.84,具有良好的相关性。实验结果证明了利用星载GNSS-R的功率比及相关特性实现太湖水华检测的可行性。

关键词：气旋全球导航卫星系统全球导航卫星系统反射信号功率比水色遥感仪器最大特征峰高度算法

2005-2022年济南市急性出血性结膜炎流行特征分析

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社区医学杂志 2024年第11期22卷 373-377页

作者：王加坤郑文华韩燕玲济南市疾病预防控制中心药械管理部山东济南250021

目的分析2005-2022年济南市急性出血性结膜炎(AHC)流行特征,为制定监测和预防控制措施提供科学依据。方法通过中国疾病预防控制信息系统收集2005-2022年济南市AHC疫情数据,采用描述性流行病学方法分析流行特征。结果2005-2022年济南市... 详细信息

目的分析2005-2022年济南市急性出血性结膜炎(AHC)流行特征,为制定监测和预防控制措施提供科学依据。方法通过中国疾病预防控制信息系统收集2005-2022年济南市AHC疫情数据,采用描述性流行病学方法分析流行特征。结果2005-2022年济南市共报告AHC为835例,年均发病率0.65/10万,分别在2010和2019年出现2个发病高峰,其余时间保持在较低发病水平;中心城区年均发病率显著高于非中心城区,差异有统计学意义,χ^(2)=58.16,P<0.001;发病主要集中在8-10月,9月份发病最多,占25.27%;男性年均发病率显著高于女性,差异有统计学意义,χ^(2)=29.81,P<0.001;50岁以下病例占79.04%,21~30岁年龄组发病最多占20.24%;职业以农民、学生、工人、幼托儿童和散居儿童为主,学生发病数和占比逐年下降(χ^(2)_(趋势)=84.15,P<0.001),农民发病数和占比逐年上升,χ^(2)_(趋势)=173.90,P<0.001;76.05%的病例能在3 d内诊断,散居儿童诊断及时性显著低于学生、农民、工人、幼托儿童,差异有统计学意义,χ^(2)=32.29,P=0.001。结论2005-2022年济南市AHC疫情总体处于较低发病水平,未出现每隔几年发生一次大流行的情况,应及时开展流行病学和病原学主动监测,强化预防措施,防止聚集性疫情发生。

关键词：急性出血性结膜炎流行特征发病率济南市

Certain Curvature Conditions on P-Sasakian Manifolds Admitting a Quater-Symmetric Metric Connection

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Chinese Annals of Mathematics,Series B 2020年第1期41卷 133-146页

作者： Uday Chand DE Peibiao ZHAO Krishanu MANDAL yanling han Department of Pure Mathematics University of Calcutta35 Ballygunge Circular RoadKol-700019West BengalIndia Department of Mathematics Nanjing University of Science and TechnologyNanjing 210094China School of Mathematics and Statistics Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China

The authors consider a quarter-symmetric metric connection in a P-Sasakian manifold and study the second order parallel tensor in a P-Sasakian manifold with respect to the quarter-symmetric metric connection. Then Ricci semisymmetric P-Sasakian manifold with respect to the quarter-symmetric metric connection is considered. Next the authors study ξ-concircularly flat P-Sasakian manifolds and concircularly semisymmetric P-Sasakian manifolds with respect to the quarter-symmetric metric connection. Furthermore, the authors study P-Sasakian manifolds satisfying the condition Z(ξ,Y)·S=0,where Z,S are the concircular curvature tensor and Ricci tensor respectively with respect to the quarter-symmetric metric connection. Finally, an example of a 5-dimensional P-Sasakian manifold admitting quarter-symmetric metric connection is constructed.

关键词： Quarter-symmetric metric connection P-Sasakian manifold Ricci semisymmetric manifold ξ-Concircularly flat Concircularly semisymmetric

Theoretical probe into universal tetrad effect for complexation discrepancy between lanthanide elements and organophosphoric extractant diethyl phosphoric acid

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Journal of Rare Earths 2024年第6期42卷 1142-1148,I0006页

作者： Haifeng Zheng yanling Li Xuyi Zhang Jinglu han Songsong Li Guolong Wu Qingshi Liu Xiaojuan Liu Wuping Liao State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China University of Science and Technology of China Hefei230026China School of Chemistry and Chemical Engineering Nanchang UniversityNanchang330031China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341000China

The deep understanding of 4f-correlated electron motion behavior is experimentally limited due to similar physicochemical properties of rare earth elements(REEs).While the solvent extraction behavior originating from the continuous occupation of 4f electrons along the lanthanide family provides a particular platform to probe the 4f electrons motion behavior and its correlations to their versatile ***,the complexation between REEs and the prototypical extractant of diethyl phosphoric acid(DEP)was substantially studied based on quantum mechanical *** results firstly show that the average bond lengths between Ln and six coordinated oxygen atoms are consistent with lanthanide contraction phenomenon,and gadolinium break effect is also obviously ***,the"tetrad effect"is figured out based on the subtle discrepancy of 4f electrons occupation,namely La-Nd,Sm-Eu,Gd-Dy and ***,the main composition is 4f5d6p for La-Nd,while the discrepancy is due to the increasing electrons in the 5d shell,while it is 4f5d for *** Gd-Dy,their 4f orbitals accept little electrons and the donating electrons flow into 6s5d subshells due to the half-filled stability and the enhancement of shielding *** electrons donate into 5d6p subshells due to multiply electrons occupation of 4f orbitals for *** detailed analyses obviously clarify the"tetrad effect"along the lanthanide family due to the different variation of 4f orbital *** is expected that these microscopic understandings provide important guidance for the separation of REEs and the design of new extractants.

关键词： Theoretical calculation Rare earths 4f electron Tetrad effect Gadolinium break

Excitation of localized modes and mechanism of random lasing forming in random media

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Chinese Science Bulletin 2006年第18期51卷 2178-2182页

作者： WANG Hong LIU Jinsong WANG Kejia han yanling State Key Laboratory of Laser Technology Huazhong University of Science and Teelmology Wuhan 430074 China

Laser phenomena in random media have been studied based on the localized theory for lightwave in random media. The relationship between random lasing modes and localized modes has been investigated by directly solving Maxwell equations numerically via the finite difference time domain method. The spatial distribution and the spectra of localized modes are obtained for both passive and active random media. The results show that random lasing modes directly originate from the localized modes inside the random medium. In the presence of gain, any one of the localized modes can be amplified and can serve as random lasing mode.

关键词：激光物理学光学性能激光作用随机媒质

Automatic sub-pixel coastline extraction based on spectral mixture analysis using EO-1 Hyperion data

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Frontiers of Earth Science 2019年第3期13卷 478-494页

作者： Zhonghua HONG Xuesu LI yanling han Yun ZhanG Jing WANG Ruyan ZHOU Kening HU College of Information Technology Shanghai Ocean UniversityShanghai 201306China Key Laboratory of Fisheries Information Ministry of AgricultureShanghai 201306China

Many megacities (such as Shanghai) are located in coastal areas, therefore, coastline monitoring is critical for urban security and urban development sustainability. A shoreline is defined as the intersection between coastal land and a water surface and features seawater edge movements as tides rise and fall. Remote sensing techniques have increasingly been used for coastline extraction;however, traditional hard classification methods are performed only at the pixel-level and extracting subpixel accuracy using soft classification methods is both challenging and time consuming due to the complex features in coastal regions. This paper presents an automatic sub-pixel coastline extraction method (ASPCE) from high-spectral satellite imaging that performs coastline extraction based on spectral mixture analysis and, thus, achieves higher accuracy. The ASPCE method consists of three main components: 1) A Water-Vegetation-Impervious-Soil (W-V-I-S) model is first presented to detect mixed W-V-I-S pixels and determine the endmember spectra in coastal regions;2) The linear spectral mixture unmixing technique based on Fully Constrained Least Squares (FCLS) is applied to the mixed W-V-I-S pixels to estimate seawater abundance;and 3) The spatial attraction model is used to extract the coastline. We tested this new method using EO-1 images from three coastal regions in China: the South China Sea, the East China Sea, and the Bohai Sea. The results showed that the method is accurate and robust. Root mean square error (RMSE) was utilized to evaluate the accuracy by calculating the distance differences between the extracted coastline and the digitized coastline. The classifier’s performance was compared with that of the Multiple Endmember Spectral Mixture Analysis (MESMA), Mixture Tuned Matched Filtering (MTMF), Sequential Maximum Angle Convex Cone (SMACC), Constrained Energy Minimization (CEM), and one classical Normalized Difference Water Index (NDWI). The results from the three tes

关键词： coastline fully constrained least squares spatial attraction algorithm urban development EO-1 data

Effectiveness of Frequent Viral Load Testing Plus Additional Interventions to Prevent HIV Transmission in Heterosexual,Serodiscordant Couples—Yunnan Province,China,2019-2021

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China CDC weekly 2024年第27期6卷 658-664,I0001-I0004页

作者： Jing han Jian Li Yuhua Shi Chunpeng Zang Zhimin Yang Yu han yanling Ma Qiongli Duan Yuhua Hu Zikuang Bai Cuiyun Yang Gabriella Bulloch Yurong Mao Houlin Tang Zunyou Wu Yufen Liu National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Yunnan Provincial Center for Disease Control and Prevention Kunming CityYunnan ProvinceChina Honghe Prefectural Center for Disease Control and Prevention Honghe CityYunnan ProvinceChina Wenshan Prefectural Center for Disease Control and Prevention Wenshan CityYunnan ProvinceChina Zhaotong Prefectural Center for Disease Control and Prevention Zhaotong CityYunnan ProvinceChina Lincang Prefectural Center for Disease Control and Prevention Lincang CityYunnan ProvinceChina Faculty of Medicine Dentistry and Health SciencesUniversity of MelbourneMelbourneVICAustralia

Summary What is already known about this topic?HIV transmission among serodiscordant couples remains a persistent issue in ***,the practice of combining counseling with antiretroviral therapies(ART)to enhance ART adhe... 详细信息

关键词： China. ant discord