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Bayesian machine learning-based method for prediction of slope failure time

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1188-1199页

作者： Jie Zhang Zipeng Wang Jinzheng Hu Shihao Xiao wenyu shang Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education Tongji UniversityShanghai200092China Department of Geotechnical Engineering Tongji UniversityShanghai200092China Natural Science College Michigan State UniversityMI48825USA

The data-driven phenomenological models based on deformation measurements have been widely utilized to predict the slope failure time(SFT).The observational and model uncertainties could lead the predicted SFT calculated from the phenomenological models to deviate from the actual ***,very limited study has been conducted on how to evaluate the effect of such uncertainties on SFT *** this paper,a comprehensive slope failure database was compiled.A Bayesian machine learning(BML)-based method was developed to learn the model and observational uncertainties involved in SFT prediction,through which the probabilistic distribution of the SFT can be *** method was illustrated in detail with an *** studies show that the BML-based method is superior to the traditional inverse velocity method(INVM)and the maximum likelihood method for predicting *** proposed method in this study provides an effective tool for SFT prediction.

关键词： Slope failure time(SFT) Bayesian machine learning(BML) Inverse velocity method(INVM)

Elevational distribution of forests and its spatiotemporal dynamics in subtropical China from 2000 to 2019

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Science China Earth Sciences 2024年第8期67卷 2563-2582页

作者： Zhencan ZHENG Liuwen ZHUANG Guofang MIAO Han LIU Zhiqiang CHENG wenyu LI Rong shang Peng GONG Jing Ming CHEN Institute of Geography Fujian Normal University Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education) Fujian Normal University School of Geographical Sciences Fujian Normal University National Land Consolidation Center Ministry of Natural Resources Key Laboratory of Land Consolidation and Rehabilitation Ministry of Natural Resources Key Laboratory of Digital Mapping and Land Information Application Ministry of Natural Resources Department of Geography & Planning University of Toronto Department of Geography The University of Hong Kong

The subtropical region of China possesses abundant forest resources and features a mountainous *** the implementation of policies such as natural forest protection,the Grain for Green Project,and other initiatives since the beginning of the 21st century,coupled with climate change,the forest resources in this region have undergone significant changes compared to historical *** addition,forest resources distributing mainly in mountainous areas also implies that these changes may vary significantly with *** explore the spatiotemporal dynamics of forest distribution in subtropical China since 2000,especially the trend of changes with elevation,we analyzed the data from two land cover products focusing on forest cover and forest *** used a hierarchical approach,in which coarse-classification forest cover data with relatively small uncertainties impose constraints on forest type data with larger uncertainties,to achieve a reasonable balance between obtaining more details and reducing data *** first divided the forest cover data into‘unchanged'and‘changed'*** the constraints by the forest cover results,we further analyzed the‘unchanged'and‘changed'forest *** results indicated that,since the implementation of ecological engineering and management policies,54%of the area in the subtropical region had maintained unchanged forest cover attributes over the past 20 years,which implied the good state of ecological *** results also showed that dynamic conversions existed in the long term between forests and lands for essential production needs like *** elevational variations of forest cover suggested that the dominant changes came from the conversion between forests and croplands in low-elevation regions below 700 m,the conversion between forests and shrublands in mid-elevation regions of 700–1500 m,and the conversion between forests and grasslands in high-elevation regions above 2000 *** the regio

关键词： Subtropical China Land cover Forest cover Forest type Elevational distribution

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连续梁桥影响线识别与承载能力快速评估试验研究

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振动与冲击 2024年第7期43卷 334-344页

作者：周宇尚稳齐狄生奎郑旭贺文宇安徽建筑大学土木工程学院合肥230601 安徽建筑大学建筑健康监测与灾害预防技术国家地方联合工程实验室合肥230601 兰州交通大学土木工程学院兰州730070 大连理工大学土木工程学院大连116023 合肥工业大学土木与水利工程学院合肥230009

针对桥梁静载试验过程存在的重载静置、交通阻误等问题,利用桥梁影响线具有完整反映结构各截面抗弯刚度的优势,提出一种基于影响线的桥梁承载能力快速评估方法。该方法仅利用单辆重车移动加载获取包含桥梁影响线信息、结构动力成分和车... 详细信息

针对桥梁静载试验过程存在的重载静置、交通阻误等问题,利用桥梁影响线具有完整反映结构各截面抗弯刚度的优势,提出一种基于影响线的桥梁承载能力快速评估方法。该方法仅利用单辆重车移动加载获取包含桥梁影响线信息、结构动力成分和车辆多轴效应的桥梁时程响应,首先采用变分模态分解剥离桥梁时程响应中的动力成分;其次根据采样频率及车辆轴距构建桥梁影响线识别数学模型,从而剔除桥梁时程响应中的车辆多轴效应,利用Tikhonov正则化解得桥梁影响线的稳定解;然后通过在桥梁影响线上开展虚拟加载,重构桥梁虚拟静力响应,并采用传统校验系数法评价桥梁承载能力。通过三跨变截面连续梁桥数值算例验证影响线识别方法的有效性,建立误差指标定量评价影响线识别结果的准确性,从而对某三跨连续钢混组合梁桥开展静载试验与承载能力快速评估试验研究,在预设车道实施车辆移动加载,识别桥梁中跨跨中截面挠度、应变影响线,进而开展虚拟加载研究,进一步验证所提承载能力快速评估方法的可行性与实用性,为桥梁承载能力“轻量化”快速筛检提供方法支撑与案例借鉴。

关键词：连续梁桥影响线识别变分模态分解(VMD) 承载能力快速评估

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气液法合成文石型碳酸钙晶须的研究

西安交通大学学报 1999年第10期33卷 10-13页

作者：尚文宇刘庆峰陈寿田西安交通大学西安710049

研究了用气液法制备文石型ＣａＣＯ２晶须时，温度、初始ｐＨ值、结晶促进剂等工艺因素对晶须生长的影响，利用Ｘ射线衍射分析了试样中文石型ＣａＣＯ３的质量分数．通过实验发现，在Ｈ３ＰＯ４或可溶性磷酸盐的作用下，Ｃａ（ＯＨ... 详细信息

研究了用气液法制备文石型ＣａＣＯ２晶须时，温度、初始ｐＨ值、结晶促进剂等工艺因素对晶须生长的影响，利用Ｘ射线衍射分析了试样中文石型ＣａＣＯ３的质量分数．通过实验发现，在Ｈ３ＰＯ４或可溶性磷酸盐的作用下，Ｃａ（ＯＨ）２悬浊液具有类似的碳酸化过程，但采用Ｈ３ＰＯ４或酸性磷酸盐时，反应的渗流效应比采用碱性磷酸盐显著，所得产物中文石质量分数也较高．适宜于文石型ＣａＣＯ３生长的温度范围为２５～７５ ℃；初始酸度值范围为８－６～１２－４．通过对比Ｃａ３（ＰＯ４）２和ＣａＨＰＯ４对晶须生长的影响，发现可以作为文石型ＣａＣＯ３晶核的成份为ＣａＨＰＯ４而非Ｃａ３（ＰＯ４）２．

关键词：晶须气液法合成碳酸钙文石型

Seasonal temperature variability during the past 1600 years recorded in historical documents and varved lake sediment profiles from northeastern China

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Seasonal temperature variability during the past 1600 years ...

Minor element variations during the past 1 300 years in the varved sediments of Lake Xiaolongwan,north-eastern China

中国科学院地质与地球物理研究所2012年度（第12届）...

作者： Guoqiang Chu Qing Sun Xiaohua Wang Meimei Liu Yuan Lin Manman Xie wenyu shang Jiaqi Liu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of Sciences National Research Center of Geoanalysis China University of Geosciences Shanxi Experimental Institute of Geology and Mineral resources

Seasonal temperature variability over longer timescales could offer new insights into understanding different forcing factors and response processes in the climate *** we report an alkenone-based temperature reconstruction for growing season over the past 1600 years from the varved sediment in Lake Sihailongwan,northeastern *** most notable cold spells occurred during the periods ad 480—860,ad 1260-1300,ad 1510—1570 and ad 1800—1900 with a temperature decrease of about I℃compared with the 20th *** on the historical evidence such as ’snow or frost in the summertime’ and ’no ice during the wintertime’,we compile extreme cold summer events and warm winter events over the past 1600 *** ’Little Ice Age’ time period experienced more extreme cold summer/warm winter events,while the ’Medieval Warm Period’ had milder ***, the natural proxy data show a general similar pattern with historical documents at decadal time scales,except for between ad 1620 and *** results show multidecadal to centennial variations in seasonal temperature,possibly caused by interactions of external natural forcing and atmosphere—ocean circulations.

关键词： alkenone unsaturation index atmosphere-ocean circulations historical documents seasonal temperature extreme varved sediments

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Minor element variations during the past 1 300 years in the ...

地方法人金融机构同业业务快速发展的风险及对策

中国科学院地质与地球物理研究所2013年度（第13届）...

作者： GUOQIANG CHU QING SUN SHENGQIANG LI YUAN LIN XIAOHUA WANG MANMAN XIE wenyu shang AIGUO LI KE YANG Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of Sciences National Research Center of Geoanalysis Institute of Earthquake Science CEA shanghai Synchrotron Radiation Facility Shanghai Institute of Applied PhysicsChinese Academy of Sciences

Synchrotron radiation X-ray fluorescence measurement provides a nondestructive in situ analysis of *** present a high-resolution minor element dataset covering the past 1300 years from the varved sediments in Lake *** variations of lithogenic elements(Rb,Sr,Ti,Zn, As and Fe) in the lake sediment show distinct decadal to centennial features during the past 1300 years. The Medieval Warm Period has a low value of lithogenic *** contrast,the Little Ice Age may be a period with stronger physical weathering and a higher value of lithogenic *** components analysis of our geochemical dataset suggests a link between high Rb/Sr ratio and Zr abundance in the sediment that could be related with both chemical weathering process and dust input. The variations of biogenic bromine(factor-3) show a pattern similar to the decadal drought index in *** conditions favor bromine accumulation in lake sediment because high precipitation may transport more bromine from forest soil and increase plankton production in the *** analysis of factor-3 yields notable periodicities of 2.6,3.5,53-55,87-89 and 105-110 years,implying that precipitation variability for the past 1400 years could be associated with E1 Nino-Southern Oscillation and solar activity.

关键词： varved sediment Lake Xiaolongwan synchrotron radiation X-ray fluorescence bromine

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西部金融 2014年第6期 62-63页

作者：商文瑜中国人民银行西安分行营业管理部陕西西安710002

同业业务是金融机构调整资产负债结构、减少资本占用、增加经营收益的重要工具。地方法人金融机构同业业务快速发展的同时也对银行流动性管理、系统性风险防范、金融业宏观调控提出挑战。本文对防范同业业务风险的具体做法进行总结,并... 详细信息

同业业务是金融机构调整资产负债结构、减少资本占用、增加经营收益的重要工具。地方法人金融机构同业业务快速发展的同时也对银行流动性管理、系统性风险防范、金融业宏观调控提出挑战。本文对防范同业业务风险的具体做法进行总结,并提出相关建议。

关键词：商业银行同业业务风险管理

中国东北干旱-半干旱地区湖泊沉积物木质素酚类化合物特征及其气候指示意义

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岩矿测试 2023年第2期42卷 346-360页

作者：尚文郁孙青谢曼曼战楠自然资源部生态地球化学重点实验室国家地质实验测试中心北京100037

木质素广泛分布于维管植物,经分解生成的酚类化合物可示踪有机质来源、评估木质素降解程度,进而用于反演古环境与古气候变化。采用合适的分析方法有效地分解木质素是推断母源植物类型、降解程度的技术基础,常规方法是木质素经碱(或酸)解... 详细信息

木质素广泛分布于维管植物,经分解生成的酚类化合物可示踪有机质来源、评估木质素降解程度,进而用于反演古环境与古气候变化。采用合适的分析方法有效地分解木质素是推断母源植物类型、降解程度的技术基础,常规方法是木质素经碱(或酸)解后,利用气相色谱-质谱法(GC-MS)分析酚类单体化合物,但分解、提取过程复杂、易引入杂质。热裂解技术可在高温下快速分解有机质,裂解产物可通过GC-MS进行在线分析,具有用样量少、有机质提取比例高、重现性好、操作便捷的特点。本文选择地处亚洲夏季风影响区域的边缘的内蒙伊和沙日乌苏湖,采用热裂解GC-MS(Py-GC/MS)技术,对湖泊沉积物进行裂解分析,在对裂解温度(450℃、550℃和650℃)进行了优化的基础上,识别了21种酚类化合物,包括:4-甲基苯酚、2-乙基苯酚等9种烷基酚类(PHs),4-乙基-2-甲氧基苯酚、4-乙烯基-2,6-二甲氧基苯酚等9种烷基酚类(PHs)和12种甲氧基酚类(LGs)。结合沉积岩心样品AMS 14 C年龄的分析结果,6.7 ka以来沉积物中酚类化合物总量、PHs和LGs的变化趋势总体一致,呈现出6.7~4.0ka相对含量较高、4.0ka以来相对含量较低的特征。不同于PHs中邻(o-)-PHs、间(m-)-PHs、对(p-)-PHs的变化趋势与总量一致;但不同取代特征的LGs相对含量变化趋势存在差异,p-LGs在5.4ka前后就出现含量显著下降,3.8ka以来维持较低水平。根据微生物对木质素的“去甲基/去甲氧基”氧化反应途径,对位取代酚类化合物比值(p-PHs/p-LGs)可作为陆生高等植物降解指标,该值越大微生物降解作用越强。将p-PHs/p-LGs指标应用于伊和沙日乌苏沉积物样品结果显示,6.7ka以来p-PHs/p-LGs与正构烷烃单体碳同位素δ^(13) C_(27-33)变化趋势一致(R=-0.77),间接地指示了有效降水变化。即6.7ka以来气候整体转湿,区内陆生高等植物占据优势,充足的水分和有机质为微生物提供了适宜的生存环境和相对稳定的营养来源,降解作用整体呈增强趋势;6.3~5.5ka和4.1~3.6ka期间有效湿度降低,微生物对木质素的降解作用相对减弱。p-PHs/p-LGs指标对应了呼伦贝尔地区湿度变化特征,揭示了干旱-半干旱地区微生物降解与有效湿度变化的相关性,为探讨陆地生态系统对东亚季风北部边缘区气候变化的响应提供科学依据。

关键词：热裂解-气相色谱-质谱法伊和沙日乌苏湖木质素酚类单体化合物微生物降解古气候

维普期刊数据库博看期刊

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社区银行发展现状及对策建议

西部金融 2014年第10期 71-73页

作者：商文瑜中国人民银行西安分行营业管理部陕西西安710002

随着我国金融体制改革的逐步深入,金融机构正在逐渐调整以求适应改革的进程。近年来,我国银行零售领域变革最引人注目的是中小商业银行的社区银行探索,社区银行是我国金融市场化发展的必然产物,对满足中小企业和社区居民金融消费需求,... 详细信息

随着我国金融体制改革的逐步深入,金融机构正在逐渐调整以求适应改革的进程。近年来,我国银行零售领域变革最引人注目的是中小商业银行的社区银行探索,社区银行是我国金融市场化发展的必然产物,对满足中小企业和社区居民金融消费需求,促进区域经济发展具有重要意义,本文对西安市社区银行发展现状进行总结,分析其中存在问题,并提出相关建议。

关键词：金融体制改革金融市场社区银行