检索结果-南通市图书馆

Assessing the effects of model parameter assumptions on surface-wave inversion results

Earthquake Science 2024年第6期37卷 529-545页

作者： xuezhen zhang Xiaodong Song SinoProbe Laboratory School of Earth and Space SciencesPeking UniversityBeijing 100871China Hebei Hongshan National Observatory on Thick Sediments and Seismic Hazards Beijing 100871China

Surface-wave inversion is a powerful tool for revealing the Earth's internal ***,aside from shear-wave velocity(v_(S)),other parameters can influence the inversion outcomes,yet these have not been systematically *** study investigates the influence of various parameter assumptions on the results of surface-wave inversion,including the compressional and shear velocity ratio(v_(P)/v_(S)),shear-wave attenuation(Q_(S)),density(ρ),Moho interface,and sedimentary *** constructed synthetic models to generate dispersion data and compared the obtained results with different parameter assumptions with those of the true *** results indicate that the v_(P)/v_(S) ratio,Q_(S),and density(ρ) have minimal effects on absolute velocity values and perturbation patterns in the ***,assumptions about the Moho interface and sedimentary layer significantly influenced absolute velocity values and perturbation *** an erroneous Mohointerface depth in the initial model of the inversion significantly affected the v_(S) model near that depth,while using a smooth initial model results in relatively minor *** assumption on the sedimentary layer not only affects shallow structure results but also impacts the result at greater ***-linear inversion methods outperform linear inversion methods,particularly for the assumptions of the Moho interface and sedimentary *** inversion with other data types,such as receiver functions or Rayleigh wave ellipticity,and using data from a broader period range or higher-mode surface waves,can mitigate these ***,incorporating more accurate prior information can improve inversion results.

关键词： shear-wave velocity model surface-wave inversion Moho interface sedimentary layer non-linear inversion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Crustal and uppermost mantle structure of the northeastern Qinghai-Xizang Plateau from joint inversion of surface wave dispersions and receiver functions with P velocity constraints

引用

Earthquake Science 2024年第2期37卷 93-106页

作者： Pei zhang Xiaodong Song Jiangtao Li Xingchen Wang xuezhen zhang Institute of Geophysics China Earthquake AdministrationBeijing 100081China The Second Monitoring and Application Center China Earthquake AdministrationXi'an 710054China Institute of Theoretical and Applied Geophysics School of Earth and Space SciencesPeking UniversityBeijing 100871China Department of Geophysics School of Geodesy and GeomaticsWuhan UniversityWuhan 430079China

Lithospheric structure beneath the northeastern Qinghai-Xizang Plateau is of vital significance for studying the geodynamic processes of crustal thickening and expansion of the Qinghai-Xizang Plateau. We conducted a joint inversion of receiver functions and surface wave dispersions with P-wave velocity constraints using data from the Chin Array Ⅱ temporary stations deployed across the Qinghai-Xizang Plateau. Prior to joint inversion, we applied the H-κ-c method(Li JT et al., 2019) to the receiver function data in order to correct for the back-azimuthal variations in the arrival times of Ps phases and crustal multiples caused by crustal anisotropy and dipping interfaces. High-resolution images of vS, crustal thickness, and vP/vSstructures in the Qinghai-Xizang Plateau were simultaneously derived from the joint inversion. The seismic images reveal that crustal thickness decreases outward from the Qinghai-Xizang Plateau. The stable interiors of the Ordos and Alxa blocks exhibited higher velocities and lower crustal vP/vSratios. While, lower velocities and higher vP/vSratios were observed beneath the Qilian Orogen and Songpan-Ganzi terrane(SPGZ), which are geologically active and mechanically weak, especially in the mid-lower *** or thermal erosion of the lithosphere triggered by hot asthenospheric flow contributes to the observed uppermost mantle low-velocity zones(LVZs) in the SPGZ. The crustal thickness, vS, and vP/vSratios suggest that whole lithospheric shortening is a plausible mechanism for crustal thickening in the Qinghai-Xizang Plateau, supporting the idea of coupled lithospheric-scale deformation in this region.

关键词： joint inversion receiver functions surface waves crustal thickness vP/vS ratio NE Qinghai-Xizang Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mapping cropping patterns in the North China Plain over the past 300 years and an analysis of the drivers of change

引用

Journal of Geographical Sciences 2024年第10期 2074-2088页

作者： LI Shicheng LIU Yating LI Jianrui zhang xuezhen School of Public Administration China University of Geosciences Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS College of Resources and Environment University of Chinese Academy of Sciences

It is essential to map the cropping patterns when investigating the mechanisms and impacts of climate change. However, the long-term evolution of cropping patterns remains poorly understood. This study collected hundreds of records of cropping intensity and crop combinations from local gazetteers and other relevant articles for the North China Plain(NCP)over the past 300 years. Then, we analyzed the evolutionary characteristics and drivers in terms of climate change and advances in agricultural technology. From the Qing Dynasty to the 1950s, one harvest per year(1H1Y) was the dominant pattern in the northern NCP, and three harvests in two years(3H2Y) was the dominant pattern in Henan and Shandong provinces. The 1H1Y crops were cereals and sorghum. The 3H2Y crop combinations were spring maize, winter wheat, and beans. In the 1960s and 1970s, the cropping intensity in much of the NCP was two harvests per year(2H1Y) or a mix of the 2H1Y and 3H2Y patterns. In the 1980s, the cropping intensity in the NCP was dominated by 2H1Y. Since the 1960s, the 2H1Y crop compositions have been winter wheat-summer maize in Shandong, Henan, and Hebei provinces, while winter wheat-rice dominated north of the Huaihe River. The 3H2Y summer crop changed from beans to maize/cereals over time. Climate warming was not the dominant factor driving the evolution of cropping intensity in the NCP. Advances in agricultural production conditions and reforms in production relations have promoted the rapid development of multiple cropping since the 1950s.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Mapping cropping patterns in the North China Plain over the past 300 years and an analysis of the drivers of change

引用

Journal of Geographical Sciences 2024年第10期34卷 2074-2088页

作者： LI Shicheng LIU Yating LI Jianrui zhang xuezhen School of Public Administration China University of GeosciencesWuhan 430074China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

It is essential to map the cropping patterns when investigating the mechanisms and impacts of climate ***,the long-term evolution of cropping patterns remains poorly *** study collected hundreds of records of cropping intensity and crop combinations from local gazetteers and other relevant articles for the North China Plain(NCP)over the past 300 ***,we analyzed the evolutionary characteristics and drivers in terms of climate change and advances in agricultural *** the Qing Dynasty to the 1950s,one harvest per year(1H1Y)was the dominant pattern in the northern NCP,and three harvests in two years(3H2Y)was the dominant pattern in Henan and Shandong *** 1H1Y crops were cereals and *** 3H2Y crop combinations were spring maize,winter wheat,and *** the 1960s and 1970s,the cropping intensity in much of the NCP was two harvests per year(2H1Y)or a mix of the 2H1Y and 3H2Y *** the 1980s,the cropping intensity in the NCP was dominated by *** the 1960s,the 2H1Y crop compositions have been winter wheat-summer maize in Shandong,Henan,and Hebei provinces,while winter wheat-rice dominated north of the Huaihe *** 3H2Y summer crop changed from beans to maize/cereals over *** warming was not the dominant factor driving the evolution of cropping intensity in the *** in agricultural production conditions and reforms in production relations have promoted the rapid development of multiple cropping since the 1950s.

关键词： North China Plain Qing Dynasty cropping intensity crop combinations crop harvest frequency climate change

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

预制菜C端消费者购买行为及影响因素

引用

中国农业大学学报 2024年第9期29卷 179-191页

作者：张学靕项朝阳华中农业大学经济管理学院武汉430070

为把握预制菜C端消费者真实感受和需求,探索预制菜有效对接市场的实践路径,基于810份调研数据,系统总结了预制菜C端消费者购买行为特征,进一步以消费价值理论为理论基础,构建了C端消费者预制菜购买意愿的影响因素模型。结果表明:1)预制... 详细信息

为把握预制菜C端消费者真实感受和需求,探索预制菜有效对接市场的实践路径,基于810份调研数据,系统总结了预制菜C端消费者购买行为特征,进一步以消费价值理论为理论基础,构建了C端消费者预制菜购买意愿的影响因素模型。结果表明:1)预制菜C端市场发展潜力大,主要受众为女性、在职消费者,以中青年、高知人群及忙碌群体为主;2)预制菜C端消费者购买动机、品类偏好、购买渠道、消费场景以及产品信息偏好呈现明显差异;3)感知品质价值、感知情感价值以及感知便捷价值对预制菜购买意愿具有显著正向影响,感知社会价值负向影响C端消费者的购买意愿。本研究,为预制菜企业提出拓宽产品线、实施差异化产品推广策略等营销建议。

关键词：预制菜 C端消费者结构方程模型消费价值理论预制菜购买行为特点预制菜购买意愿

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

清代以来华北平原作物熟制演变重建与驱动力分析

引用

地理学报 2024年第3期79卷 765-778页

作者：李士成刘亚婷李建蕊张学珍中国地质大学(武汉)公共管理学院武汉430074 中国科学院地理科学与资源研究所中国科学院陆地表层格局与过程重点实验室北京100101 中国科学院大学资源与环境学院北京100049

历史土地集约利用重建是深入探究气候变化机制和影响的基础。本文从地方志和期刊论文中提取了清代以来华北平原不同地区(点)、不同时段的作物熟制及种植组合信息,据此重建了清代、中华民国(1912—1949年)、20世纪50年代、20世纪60年代... 详细信息

历史土地集约利用重建是深入探究气候变化机制和影响的基础。本文从地方志和期刊论文中提取了清代以来华北平原不同地区(点)、不同时段的作物熟制及种植组合信息,据此重建了清代、中华民国(1912—1949年)、20世纪50年代、20世纪60年代、20世纪70年代、20世纪80年代以来6个时段华北平原作物熟制及主要种植组合的时空演变,并探讨了其驱动力。结果表明:(1)清代至20世纪50年代华北平原作物熟制较稳定,以一年一熟和两年三熟为主,一年一熟主要集中在平原北部,两年三熟则多分布在河南和山东省。在灌溉和农业技术的驱动下,20世纪60—70年代华北平原大部分地区作物熟制演进为一年两熟、一年两熟与两年三熟混合,20世纪80年代以来则以一年两熟为主。(2)清代至20世纪50年代华北平原作物种植组合较稳定,一年一熟主要为谷、高粱等作物春种秋收,两年三熟作物组合以春玉米、冬小麦、豆类为主。20世纪60年代以来,一年两熟制作物组成在山东、河南、河北为冬小麦—夏玉米,在淮北为冬小麦—水稻;两年三熟制作物组合中夏作物由豆类发展成玉米/谷类。(3)清代以来,华北平原始终具备发展两年三熟、一年两熟的热量条件。热量变化并不是驱动华北平原清代以来熟制演变的主导因素,1949年中华人民共和国成立以来农业生产条件的改善和生产关系的变革推动了多熟制的快速发展。

关键词：华北平原过去300 a 作物熟制种植组合时空变化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

培智学校生活数学差异教学的价值与路径探究

引用

成才之路 2024年第23期 101-104页

作者：张雪珍福建省厦门市集美区特殊教育学校福建厦门361023

在生活数学课程实施中,教师要充分考虑学生在知识基础、认知能力、学习习惯等方面存在的差异,以学生为中心,实施差异教学。培智学校生活数学采取差异教学,是尊重学生差异性的体现,有助于增强学生的学习信心,培养学生的数学思维,促进学... 详细信息

在生活数学课程实施中,教师要充分考虑学生在知识基础、认知能力、学习习惯等方面存在的差异,以学生为中心,实施差异教学。培智学校生活数学采取差异教学,是尊重学生差异性的体现,有助于增强学生的学习信心,培养学生的数学思维,促进学生全面发展。在教学实践中,教师可以生活化教学目标,满足学生的差异化学习需求,以生活化教学内容,降低知识的理解难度,以生活化的教学语言,激发学生的学习热情,以生活化的教学情境,促进学生的感官参与,以生活化的教学用具,深化学生对数学概念的理解。

关键词：培智学校生活数学差异教学教学语言教学情境教学用具

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

水中添加柠檬酸对大口黑鲈耐低氧能力的影响

引用

中国水产科学 2024年第5期31卷 576-587页

作者：刘佳林于浩东陈菲菲张学振华中农业大学水产学院长江经济带大宗水生生物产业绿色发展教育部工程研究中心湖北省池塘养殖工程实验室湖北洪山实验室

为探究在水中添加柠檬酸(citricacid,CA)对处于急性低氧胁迫下的大口黑鲈(Micropterussalmoides)耐低氧能力的影响,以平均体重(18.53±0.43)g的大口黑鲈幼鱼为研究对象,向养殖水体中添加柠檬酸至终浓度分别为0 (T0)、0.01‰(T1)、0.05‰... 详细信息

为探究在水中添加柠檬酸(citricacid,CA)对处于急性低氧胁迫下的大口黑鲈(Micropterussalmoides)耐低氧能力的影响,以平均体重(18.53±0.43)g的大口黑鲈幼鱼为研究对象,向养殖水体中添加柠檬酸至终浓度分别为0 (T0)、0.01‰(T1)、0.05‰(T2)和0.10‰(T3),在初始溶解氧浓度(DO)为7.5 mg/L的水体中停止充氧,进行2.5 h的急性低氧胁迫,每0.5h测定水中DO,对照组DO为(7.5±0.2)mg/L。胁迫结束后测定抗应激能力、机体损伤与死亡率。结果显示,与对照组相比,T0组大口黑鲈血浆中应激相关指标皮质醇(COR)与乳酸(LD)含量显著升高(P<0.05),表征机体氧化损伤的丙二醛(MDA)含量显著升高,肝脏凋亡相关基因半胱氨酸蛋白水解酶3(caspase-3)基因转录水平显著升高(P<0.05);与T0组相比,T3组死亡率显著降低,血浆中COR、LD与H2O2含量显著降低(P<0.05),肝脏中caspase-3基因转录水平显著降低(P<0.05)。综上所述,急性低氧胁迫导致大口黑鲈产生氧化应激与机体损伤,甚至大量死亡; 0.1‰CA可提高大口黑鲈抗急性低氧胁迫能力,缓解急性低氧胁迫对机体的损伤并降低死亡率。

关键词：柠檬酸缓解大口黑鲈急性低氧胁迫机体损伤死亡率

来源：

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

中式镂空清水页岩砖墙在建筑外墙装饰工程实践研究

引用

陶瓷 2024年第9期 151-154,185页

作者：谢希佳张学真中建海峡建设发展有限公司福州350000

近几年来随着国家经济水平的不断提高以及城市化建设的发展,建筑装饰项目工程的实施越来越深受社会各界的重视。随之而来的,建筑工程的外墙装饰技术系统也应该与时俱进,这样才能够全面地满足建筑工程双碳战略和新型绿色城市化建设的要... 详细信息

近几年来随着国家经济水平的不断提高以及城市化建设的发展,建筑装饰项目工程的实施越来越深受社会各界的重视。随之而来的,建筑工程的外墙装饰技术系统也应该与时俱进,这样才能够全面地满足建筑工程双碳战略和新型绿色城市化建设的要求。笔者主要通过对超高泥页岩清水砖装饰外墙的研究,发现当其高厚比超出规范规定时就会导致传统配筋构造无法保证其墙体实际的砌筑稳定,并且还会经常出现主体结构和装饰墙之间需要加强拉结等问题。为此,笔者主要从建筑墙体设置砌筑基础和压顶以及加固拉结构造等方面展开研究,并对此实施防倾覆设计;最终发现可以通过对清水页岩砖凿孔深化和穿孔钢筋连接接长深化以及排布模拟深化等方法来有效解决清水页岩砖外墙装饰相关的施工问题。

关键词：清水页岩砖外墙建筑外墙外墙装饰

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Using MaxEnt Model to Guide Marsh Conservation in the Nenjiang River Basin, Northeast China

引用

Chinese Geographical Science 2019年第6期29卷 962-973页

作者： WANG Zhiliang zhang Bai zhang xuezhen Tian Hongxu Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Science Qiqihar UniversityQiqihar 161006China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China

Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of *** how to select patches of land for conservation is still a troublesome *** this study, the MaxEnt model and irreplaceability index were applied to guide marsh conservation in the Nenjiang River Basin, Northeast *** to the high accuracy of the MaxEnt model predictions(i.e., the average AUC value = 0.933), the Wuyuer River and Zhalong marshes in the downstream reaches of Wuyuer River are the optimal habitat for the Red-crowned crane and migratory *** are 22 marsh patches selected by the patch irreplaceability index for conservation, of which 12 patches had been included in the current network of protected *** other 10 patches of marsh(amounting to 1096 km^2) far from human disturbances with high NDVI(up to 0.8) and close distance to water(less than 100 m), which are excluded from the existing network of PAs, should be implemented conservation easement programs to improve the protection efficiency of ***, the marshes at Taha, Tangchi, and Lamadian should be given priority for conservation and restoration to reintroduce migratory waterfowls, as this would lessen the current isolation state of the Zhalong National Nature Reserve.

关键词： MaxEnt model irreplaceability index marsh conservation Red-crowned crane(Grus japonensis) Nenjiang River Basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：