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A general climatology of categorized Martian ionospheric irregularities

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science china Earth sciences 2024年第10期67卷 3302-3325页

作者： xin WAN Jiahao ZHONG Yongqiang HAO Chao XIONG Hui WANG Yutian cao Jun CUI Yiwen LIU qiaoling LI Jiawei KUAI planetary Environmental and Astrobiological research Laboratory(pEArL) School of Atmospheric SciencesSun Yat-sen UniversityZhuhai 519082China Key Laboratory of Tropical Atmosphere-Ocean System Ministry of EducationZhuhai 519082China Department of Space physics College of Electronic InformationLuojia LaboratoryWuhan UniversityWuhan 430079China School of physics and Electronic information Shangrao Normal UniversityShangrao 334001China School of petroleum China University of Petroleum-Beijing at KaramayKaramay 834000China college of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

A climatological survey of Martian ionospheric plasma density irregularities was conducted by exploring the in-situ measurements of the Mars Atmosphere and Volatile EvolutioN(MAVEN) spacecraft. The irregularities were first classified as enhancement, depletion, and oscillation. By checking the simultaneous magnetic field fluctuation, the irregularities have been classified into two types: with or without magnetic signatures. The classified irregularities exhibit diverse global occurrence patterns, as those with magnetic signatures tend to appear near the periphery of the crustal magnetic anomaly(MA), and those without magnetic signatures prefer to appear either inside of the MA or outside of the MA, depending on the type and solar zenith angle. Under most circumstances, the irregularities have a considerable occurrence rate at altitudes above the ionospheric dynamo height(above 200 km), and the magnetization state of the ions seems irrelevant to their occurrence. In addition, the irregularities do not show dependence on magnetic field geometry, except that the enhancement without magnetic signatures favors the vertical field line, implying its equivalence to the localized bulge. Other similarities and discrepancies exist in reference to previous studies. We believe this global survey complements previous research and provides crucial research clues for future efforts to clarify the nature of the Martian ionospheric irregularities.

关键词： Mars MAVEN Ionosphere Ionospheric irregularities Crustal magnetic anomaly plasma

Quasi-Hermite插值在一重积分Wiener空间的平均误差

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内蒙古大学学报（自然科学版） 2024年第5期55卷 449-458页

作者：曹莉马海腾杨巧玲许贵桥内蒙古医科大学计算机信息学院呼和浩特010110 天津财经大学管理可计算建模协同创新中心天津300222 天津天狮学院数理部天津301700 天津师范大学数学科学学院天津300387

在一重积分Wiener空间下确定了一种Quasi-Hermite插值多项式算子列在加权L_(p)-范数逼近意义下的L_(p)-平均误差的弱渐近阶。结果显示从信息基复杂性的角度来看,如果选取Hermite数据作为可允许的信息泛函,那么这种多项式插值算子列的p-... 详细信息

在一重积分Wiener空间下确定了一种Quasi-Hermite插值多项式算子列在加权L_(p)-范数逼近意义下的L_(p)-平均误差的弱渐近阶。结果显示从信息基复杂性的角度来看,如果选取Hermite数据作为可允许的信息泛函,那么这种多项式插值算子列的p-平均误差弱等价于相应的最小非自适应信息p-平均半径。

关键词： Quasi-Hermite插值一重积分Wiener空间平均误差 L_(p)-范数

Floral biology, breeding system and pollination ecology of an endangered tree Tetracentron sinense Oliv. (Trochodendraceae)

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Floral biology, breeding system and pollination ecology of a...

复杂地形区土地利用/土地覆被分类机器学习方法比较研究

生态文明建设中的植物学：现在与未来——中国植物学会第十五届会员代表大会暨八十周年学术年会

作者： xiaohong Gan Lingling cao Xia Zhang Huaichun Li college of Life science China West Normal University Key Laboratory of Southwest china Wildlife resources Conservation (Ministry of Education) China West Normal University Library of china West normal university

In order to explore the endangered factors related to pollination, and to provide important information for its conservation, the floral biology, breeding system and pollination ecology of T. sinense in Dafengding Natural reserve were investigated. T. sinense usually flowers by the beginning of June, and the flowering period of the population is about two months, and the florescence of florets lasted for 15 to 24 days with delicate fragrance, and fruiting period for about 3 months. The flowering dynamic of a single flower could be divided into the folowing stages: flower buds with closed sepals, sepals opening, style elongating and reflexing, the elongation of bilateral stamens, the dehiscence of bilateral anthers, the elongation of upper and lower stamens, dehiscence of bilateral anthers, the termination. During anthesis, the recurved styles were gradually positioned lower than the anthers, and the stigmas have receptivity during the whole period of anthesis. The pollen/ovule ratio is 720±28, and the outcrossing index is three. Controlled pollination experiment showed that T. sinense is self-compatible, and outbreeding fertile, with no indication of agamospermy. The germination rate of seed from xenogamy and control treatment is better than that from autogamy treatment. The occurrence of natural pollination both by wind and insects indicates T. sinense isambophilous and the maintenance of ambophily in T. sinense may attribute to the decrease of population density. Insect pollinators were predominantly represented by Coleoptera, Diptera and Hymenoptera. Syrphid fly and bees were the main effective pollinators. The results suggested that T. sinense exhibits a mixed-mating system with outcrossing and self-pollination. In the natural population, the space between scattered individuals of T. sinense is usually bigger, and its flowering period is just coincident with the rainy season, which may have negative effect on the outcrossing (wind- and insect-pollination). Thus,

关键词： Floral biology Breeding system pollination Tetracentron sinense Oliv. Natural regeneration.

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遥感技术与应用 2019年第1期34卷 57-67页

作者：谷晓天高小红马慧娟史飞飞刘雪梅曹晓敏青海师范大学地理科学学院青海省自然地理与环境过程重点实验室青海西宁810008 青海省气象科学研究所青海西宁810001 青海省气象台青海西宁810001

针对高海拔复杂地形区地貌类型复杂、多样,沟壑纵横、地形破碎等特点,研究快速、有效的土地利用/土地覆被分类方法对土地利用信息获取及更新是非常重要的。以位于黄土高原向青藏高原过渡带的湟水流域为研究区域,基于Landsat 8 OLI影像... 详细信息

针对高海拔复杂地形区地貌类型复杂、多样,沟壑纵横、地形破碎等特点,研究快速、有效的土地利用/土地覆被分类方法对土地利用信息获取及更新是非常重要的。以位于黄土高原向青藏高原过渡带的湟水流域为研究区域,基于Landsat 8 OLI影像数据、DEM数据,并结合各种专题特征,在对研究区进行地理分区的基础上,采用人工神经网络、决策树、支持向量机和随机森林4种机器学习方法进行土地利用信息提取并进行精度评价,探索适合于复杂地形区最优的分类方法。研究结果表明:随机森林和决策树的分类精度明显高于支持向量机和人工神经网络。其中随机森林方法的分类精度最高,总体分类精度达85.65%,Kappa系数达0.84。在上述分类基础上,选择随机森林分类方法对Landsat 8全色与多光谱影像融合数据进行进一步的分类研究,总体分类精度达到86.49%,Kappa系数达0.85。这表明随机森林分类方法在保证分类精度的同时又能获得较高的分类效率,对于复杂地形区土地利用信息提取是非常有效的,数据融合在一定程度上提高了分类精度。

关键词：土地利用/土地覆被分类 Landsat OLI影像机器学习人工神经网络决策树支持向量机随机森林湟水流域

河北省某高校大学生健康素养水平及影响因素研究

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科技资讯 2021年第12期19卷 251-253,256页

作者：李伟光赵晓红李志慷曹子敬牛家明河北科技师范学院体育与健康学院河北秦皇岛066004 沈阳城市建设学院体育教研部辽宁沈阳110000 许昌电气职业学院公共教学部河南许昌461000

该文为探究河北省某高校大学生的健康素养水平及其影响因素,抽取了河北省某高校561名大学生进行问卷调查。结果显示:有30.48%的学生具备健康素养,41.71%的学生具备基本知识和理念素养,18.72%的学生具备健康生活方式与行为素养,29.41%的... 详细信息

该文为探究河北省某高校大学生的健康素养水平及其影响因素,抽取了河北省某高校561名大学生进行问卷调查。结果显示:有30.48%的学生具备健康素养,41.71%的学生具备基本知识和理念素养,18.72%的学生具备健康生活方式与行为素养,29.41%的学生具备基本技能素养。性别、年级、父母文化程度是大学生健康素养水平的主要影响因素。该校学生健康素养具备率有待提高,建议学校通过强化健康教育课、加强体育与健康相融合、线上教育与线下健康教育相融合等方式将健康素养的培养融入学生的日常生活学习中,提高学生的整体健康素养水平。

关键词：河北省某高校健康素养大学生影响因素