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Margins模型及其在流行病学交互作用分析中的应用
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作者 殷国桓 董子钰 +2 位作者 阿木吉力特 叶泓 许群 《环境卫生学杂志》 2025年第9期786-791,共6页
边际效应(margins)模型作为一种基于回归的边际效应估计方法,近年来在环境健康研究中展现出独特的交互作用识别能力,尤其适用于揭示复杂暴露组合下多元交互结构的方向与强度。本文系统梳理了margins模型在环境流行病学领域的理论基础与... 边际效应(margins)模型作为一种基于回归的边际效应估计方法,近年来在环境健康研究中展现出独特的交互作用识别能力,尤其适用于揭示复杂暴露组合下多元交互结构的方向与强度。本文系统梳理了margins模型在环境流行病学领域的理论基础与实际应用,结合多种重金属混合暴露研究案例,探讨其在不同健康结局中的适用性、建模策略及解释优势。与传统交互项回归相比,margins模型可在控制协变量基础上定量刻画三元及以上交互结构,并提供明确的方向性判断;相较贝叶斯核机器回归、加权分位数和回归等非参数模型,其在高阶交互构建与亚群体分层解释方面具备良好扩展性。尽管该方法在非线性建模、高维变量选择与可视化表达方面仍存在一定局限,但其与贝叶斯方法、惩罚回归与机器学习技术的融合正在拓展其理论边界与应用前景。本文认为,margins模型有望在未来多暴露-多结局的研究框架中成为识别关键交互结构、支持因果推断与风险分层的核心工具。 展开更多
关键词 边际效应模型 多元交互作用 环境流行病学 混合暴露 流行病学
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Geochemical characteristics and genetic model of dolomite reservoirs in the eastern margin of the Pre-Caspian Basin 被引量:13
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作者 Wang Shuqin Zhao Lun +2 位作者 Cheng Xubin Fan Zifei He Ling 《Petroleum Science》 SCIE CAS CSCD 2012年第2期161-169,共9页
The widespread Carboniferous KT-I dolomite in the eastern margin of the Pre-Caspian Basin is an important hydrocarbon reservoir. The dolomite lithology is dominated by crystalline dolomite. The δ18O values range from... The widespread Carboniferous KT-I dolomite in the eastern margin of the Pre-Caspian Basin is an important hydrocarbon reservoir. The dolomite lithology is dominated by crystalline dolomite. The δ18O values range from -6.71‰ to 2.45‰, and average 0.063‰, obviously larger than -2.5‰, indicating low-temperature dolomite of evaporation origin. Stable strontium isotope ratios (87Sr/86Sr) range from 0.70829 to 0.70875 and average 0.708365, very consistent with 87Sr/86Sr ratios in Carboniferous seawater. Chemical analysis of Ca and Mg elements shows that the dolomite has 9.1 mole% excess Ca or even higher before stabilization. The degree of order of dolomite is medium–slightly poor, varying in a range of 0.336-0.504 and averaging 0.417. It suggests that the dolomite formed under near-surface conditions. There are two models for the origin of the Carboniferous KT-I dolomite reservoir. These are 1) the evaporation concentration – weathering crust model and 2) the shoal facies – seepage reflux model. The former is mainly developed in restricted platforms – evaporate platforms of restricted marine deposition environments with a representation of dolomite associated with gypsum and mudstone. The latter mainly formed in platform edge shoals and intra-platform shoals and is controlled by dolomitization due to high salinity sea water influx from adjacent restricted sea or evaporate platform. 展开更多
关键词 ISOTOPE DOLOMITE CARBONIFEROUS genetic model eastern margin of Pre-Caspian Basin
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Patterns and Dynamics of Rifting on Passive Continental Margin from Shelf to Slope of the Northern South China Sea:Evidence from 3D Analogue Modeling 被引量:14
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作者 孙珍 周蒂 +4 位作者 吴世敏 钟志洪 Myra Keep 姜建群 樊浩 《Journal of China University of Geosciences》 SCIE CSCD 2009年第1期136-146,共11页
Affected by thermal perturbation due to mantle uprising, the rheological structure of the lithosphere could be modified, which could lead to different rifting patterns from shelf to slope in a passive continental marg... Affected by thermal perturbation due to mantle uprising, the rheological structure of the lithosphere could be modified, which could lead to different rifting patterns from shelf to slope in a passive continental margin. From the observed deformation style on the northern South China Sea and analogue modeling experiments, we find that the rift zone located on the shelf is characterized by half grabens or simple grabens controlled mainly by long faults with large vertical offset, supposed to be formed with normal lithosphere extension. On the slope, where the lithosphere is very hot due to mantle upweUing and heating, composite grabens composed of symmetric grabens developed. The boundary and inner faults are all short with small vertical offset. Between the zones with very hot and normal lithosphere, composite half grabens composed of half grabens or asymmetric grabens formed, whose boundary faults are long with large vertical offset, while the inner faults are relatively short. Along with the thickness decrease of the brittle upper crust due to high temperature, the deformation becomes more sensitive to the shape of a pre-existing weakness zone and shows orientation variation along strike. When there was a bend in the pre-existing weakness zone, and the basal plate was pulled by a clockwise rotating stress, the strongest deformation always occurs along the middle segment and at the transition area from the middle to the eastern segments, which contributes to a hotter lithosphere in the middle segment, where the Baiyun (白云) sag formed. 展开更多
关键词 passive continental margin rifting pattern 3D analogue modeling South China Sea.
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Zero Truncated Bivariate Poisson Model: Marginal-Conditional Modeling Approach with an Application to Traffic Accident Data
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作者 Rafiqul I. Chowdhury M. Ataharul Islam 《Applied Mathematics》 2016年第14期1589-1598,共11页
A new covariate dependent zero-truncated bivariate Poisson model is proposed in this paper employing generalized linear model. A marginal-conditional approach is used to show the bivariate model. The proposed model wi... A new covariate dependent zero-truncated bivariate Poisson model is proposed in this paper employing generalized linear model. A marginal-conditional approach is used to show the bivariate model. The proposed model with estimation procedure and tests for goodness-of-fit and under (or over) dispersion are shown and applied to road safety data. Two correlated outcome variables considered in this study are number of cars involved in an accident and number of casualties for given number of cars. 展开更多
关键词 Bivariate Poisson Conditional model Generalized Linear model marginal model Road Safety Data Zero-Truncated
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Causal inference with marginal structural modeling for longitudinal data in laparoscopic surgery: A technical note
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作者 Zhongheng Zhang Peng Jin +7 位作者 Menglin Feng Jie Yang Jiajie Huang Lin Chen Ping Xu Jian Sun Caibao Hu Yucai Hong 《Laparoscopic, Endoscopic and Robotic Surgery》 2022年第4期146-152,共7页
Causal inference prevails in the field of laparoscopic surgery.Once the causality between an intervention and outcome is established,the intervention can be applied to a target population to improve clinical outcomes.... Causal inference prevails in the field of laparoscopic surgery.Once the causality between an intervention and outcome is established,the intervention can be applied to a target population to improve clinical outcomes.In many clinical scenarios,interventions are applied longitudinally in response to patients’conditions.Such longitudinal data comprise static variables,such as age,gender,and comorbidities;and dynamic variables,such as the treatment regime,laboratory variables,and vital signs.Some dynamic variables can act as both the confounder and mediator for the effect of an intervention on the outcome;in such cases,simple adjustment with a conventional regression model will bias the effect sizes.To address this,numerous statistical methods are being developed for causal inference;these include,but are not limited to,the structural marginal Cox regression model,dynamic treatment regime,and Cox regression model with time-varying covariates.This technical note provides a gentle introduction to such models and illustrates their use with an example in the field of laparoscopic surgery. 展开更多
关键词 Causal inference Laparoscopic surgery Machine learning marginal structural modeling
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Marginalized cubature Kalman filtering algorithm based on linear/nonlinear mixed-Gaussian model
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作者 Hu Yumei Hu Zhentao Jin Yong 《High Technology Letters》 EI CAS 2018年第4期362-368,共7页
Aiming at improving the estimation accuracy and real-time of nonlinear system with linear Gaussian sub-structure,a novel marginalized cubature Kalman filter is proposed in Bayesian estimation framework. Firstly,the ma... Aiming at improving the estimation accuracy and real-time of nonlinear system with linear Gaussian sub-structure,a novel marginalized cubature Kalman filter is proposed in Bayesian estimation framework. Firstly,the marginalized technique is adopted to model the target system dynamics with nonlinear state and linear state separately,and the two parts are estimated by cubature Kalman filter and standard Kalman filter respectively. Therefore,the linear part avoids the generation and propagation process of cubature points. Accordingly,the computational complexity is reduced.Meanwhile,the accuracy of state estimation is improved by taking the difference of nonlinear state estimation as the measurement of linear state. Furthermore,the computational complexity of marginalized cubature Kalman filter is discussed by calculating the number of floating-point operation. Finally,simulation experiments and analysis show that the proposed algorithm can improve the performance of filtering precision and real-time effectively in target tracking system. 展开更多
关键词 state estimation marginalized modeling mixed-Gaussian model CUBATURE KALMAN FILTER
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Numerical modeling of the development of southeastern Red Sea continental margin
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作者 Sunil Kumar Dwivedi Daigoro Hayashi 《Earthquake Science》 CSCD 2009年第3期239-249,共11页
The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has been studied through geological and geophysical observations primarily in regard to the evolu... The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has been studied through geological and geophysical observations primarily in regard to the evolution of Red Sea rift. This margin is characterized by occurrence of thin sediments, significant onshore uplift, tectonic subsidence of the offshore sedimentary basin, active faulting and seismicity. Studies indicate that sedimentary sequences of the margin are deformed by faults and folds resulting from at least two phases of extension and a phase of uplift. During the two phases of extension due to regional plate stress the sequence was cut by set of extensional faults. While during the phase of uplift the sequence was deformed by folding and faulting. The present paper aims to clear the structural development of RSCM during these tectonic episodes, taken as particular tectonic event, by two-dimensional finite element modeling on plane strain condition. Elastic theology is assumed for the oceanic, continental and transitional crust along with syntectonic deposits. Stress field, shear stress and fault distribution suggests that mantle plume weakened the crust following rifting due to regional stress and developed the margin. These results are well consistent with those from present seismicity, active faulting and neotectonic studies. 展开更多
关键词 Red Sea rift continental margin numerical modeling SEISMICITY NEOTECTONICS
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Stratigraphic Architecture and Computer Modelling of Carbonate Platform Margin,Late Ordovician Lianglitage Formation,Central Tarim Basin 被引量:2
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作者 李浩 林畅松 +3 位作者 张燕梅 张荣茜 芮志峰 黄理力 《Journal of Earth Science》 SCIE CAS CSCD 2012年第4期627-638,共12页
According to the different geometries and reflected characteristics in the seismic sections, the carbonate platform margin of the northern slope can be summarized as three basic depositional architectures in the Late ... According to the different geometries and reflected characteristics in the seismic sections, the carbonate platform margin of the northern slope can be summarized as three basic depositional architectures in the Late Ordovician Lianglitage (良里塔格) Formation of the Tazhong (塔中) uplift. The type one mainly located in the west of the carbonate platform margin, and it showed obvious imbricate progradation from the interior to the margin of the platform. The type two was in the middle of the carbonate platform margin, which showed retrogradational stacking pattern in the same transgres- sive systems tract period, and the slope strata of the platform margin showed progradational sequence in the highstand systems tract period. The type three located in the east of the carbonate platform margin, and it showed the parallel aggradational architecture. The crossing well section along the northern slope of the Tazhong carbonate platform showed that the depositional thickness became thinner from the east to the west. The thickest belt located in the east of the platform margin, and became thinner rapidly towards the basin and the platform interior. These indicated that the paleogeomorphology ofthe Tazhong uplift was probably high in the west and low in the east during the period of the Late Ordovician Lianglitage Formation. According to the interpretation of seismic profiles and the computer modelling result, the depositional architectures of sequence O31-2 showed aggradation, retrogradation and progradation from the east to the west of the carbonate platform margin during the transgression period. This meant that the accommodation became smaller gradually from the east to the west along the northern carbonate platform margin of the Tazhong uplift.The difference of the accommodation was probably caused by the difference of tectonic subsidence. Also, computer-aided modelling can be used to deeply understand the importance of various control parameters on the carbonate platform depositional architectures and processes. 展开更多
关键词 carbonate platform margin depositional architecture tectonic subsidence accommo-dation modelling.
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Modeling Water Quality Impacts of Growing Corn, Switchgrass, and <i>Miscanthus</i>on Marginal Soils 被引量:1
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作者 Mark A. Thomas Laurent M. Ahiablame +1 位作者 Bernard A. Engel Indrajeet Chaubey 《Journal of Water Resource and Protection》 2014年第14期1352-1368,共17页
The goal of the study was to model water quality impacts of growing perennial grasses on marginal soils. The GLEAMS-NAPRA and RUSLE models were used to simulate long-term surface runoff, percolation, erosion, total ph... The goal of the study was to model water quality impacts of growing perennial grasses on marginal soils. The GLEAMS-NAPRA and RUSLE models were used to simulate long-term surface runoff, percolation, erosion, total phosphorus (TP), and nitrate (NO3-N) losses associated with the production of corn-based bioenergy systems (i.e. conventional tillage corn and corn grain plus stover removal), switchgrass and Miscanthus on three marginal quality soils and one good quality soil in Indiana. Simulations showed that switchgrass and Miscanthus had no effect on annual runoff, but decreased percolation by at least 17%. Results also suggested a potential for reduction in erosion for Miscanthus across the soil types examined when compared to corn-based bioenergy production. The production of switchgrass and Miscanthus did not have significant effects on the simulated TP and NO3-N losses in runoff compared to corn production systems. Nitrates leached from fertilized Miscanthus production were approximately 90% lower than NO3-N leached from the production of fertilized switchgrass and corn systems. Additional studies are needed to better understand the hydrology, erosion and nutrient responses of Miscanthus and switchgrass production to meet bioenergy demands. 展开更多
关键词 Water Quality modelING Perennial Grass Runoff Biofuels marginAL Lands GLEAMS-NAPRA
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Marginal Conceptual Predictive Statistic for Mixed Model Selection
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作者 Cheng Wenren Junfeng Shang Juming Pan 《Open Journal of Statistics》 2016年第2期239-253,共15页
We focus on the development of model selection criteria in linear mixed models. In particular, we propose the model selection criteria following the Mallows’ Conceptual Predictive Statistic (Cp) [1] [2] in linear mix... We focus on the development of model selection criteria in linear mixed models. In particular, we propose the model selection criteria following the Mallows’ Conceptual Predictive Statistic (Cp) [1] [2] in linear mixed models. When correlation exists between the observations in data, the normal Gauss discrepancy in univariate case is not appropriate to measure the distance between the true model and a candidate model. Instead, we define a marginal Gauss discrepancy which takes the correlation into account in the mixed models. The model selection criterion, marginal Cp, called MCp, serves as an asymptotically unbiased estimator of the expected marginal Gauss discrepancy. An improvement of MCp, called IMCp, is then derived and proved to be a more accurate estimator of the expected marginal Gauss discrepancy than MCp. The performance of the proposed criteria is investigated in a simulation study. The simulation results show that in small samples, the proposed criteria outperform the Akaike Information Criteria (AIC) [3] [4] and Bayesian Information Criterion (BIC) [5] in selecting the correct model;in large samples, their performance is competitive. Further, the proposed criteria perform significantly better for highly correlated response data than for weakly correlated data. 展开更多
关键词 Mixed model Selection marginal Cp Improved marginal Cp marginal Gauss Discrepancy Linear Mixed model
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Gravity Modeling for the Rifted Crust at the Arabian Shield Margin – Further Insight into Red Sea Spreading
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作者 Saad Mogren Manoj Mukhopadhyay 《Open Journal of Geology》 2013年第2期28-33,共6页
A large variation in elevation and gravity anomaly prevails from the Red Sea coast to the interior of the Arabian Shield (AS) across the Asir Igneous Province (AIP);The Asir Mountain (AM) is developed on AIP. Here the... A large variation in elevation and gravity anomaly prevails from the Red Sea coast to the interior of the Arabian Shield (AS) across the Asir Igneous Province (AIP);The Asir Mountain (AM) is developed on AIP. Here the elevation varies from 45 - 2700 m, corresponding changes in F.A. are from –30 to + 220 mgal and B.A. from +22 to –175 mgal. Regression relationships between elevation and gravity anomalies demonstrate significant changes in trend at about 400 m threshold of elevation across the pediment west of AM, at about 45 km inland of the shoreline, flanking the Hizaz-Asir Escarpment (HAE). Gravity anomaly variation along a traverse taken across HAE and AIP is interpreted here in terms of anomalous masses in crust as well as due to deeper crustal configuration. 2D gravity interpretation is, in part, constrained by surface geology, available geologic cross-sections for crust, interpretations from the IRIS Deep-Seismic Refraction Line, and to a lesser extent by the available gross results from shear-wave splitting and receiver function analysis. The gravity model provides probable solutions for the first time on geometric configuration and geophysical identification: a) for the seaward margin of the mid-Tertiary Mafic Crust (TMC) below sediment cover of the Asir pediment that coincides with the 400 m threshold elevation. This signifies an anomalous uplift at the rifting phase. Moho below TMC extends from 10 - 22 km depth across HAE and west margin of AIP, b). Thinned continental crust below the Asir margin whose upper layer coincides with a seismic reflector is at about 22 km depth, c). Rift-margin characteristic detachment fault associated with basaltic flows on top surface of TMC at its inner margin, d). Two geologically mapped low-angle normal faults dipping to the east developed between the basic rocks intruding the AIP and e). felsic pluton farther east within AS. Large scale igneous activity followed by intense deformation affecting AIP clearly owes their origin to the rifting architecture of the AS at the Red Sea extensional margin. 展开更多
关键词 Shield-margin MAFIC CRUST Asir IGNEOUS Province Seismic MOHO 2D Gravity CRUSTAL model Red Sea Ex-tensional margin
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跟网型直驱风机惯量控制下系统频率响应聚合建模 被引量:1
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作者 姜超 杨冬锋 +3 位作者 郭书嘉 刘晓军 周书宇 曹志冲 《电力系统自动化》 北大核心 2025年第10期39-48,共10页
跟网型直驱风机惯量控制深刻影响系统受扰后频率响应形态。然而,目前研究并未清晰刻画出直驱风机参与频率调节主导响应环节,同时存在建模过于复杂而难以适用于频率特性分析的问题。因此,根据空气动力学方程、发电机模型、功率控制环节... 跟网型直驱风机惯量控制深刻影响系统受扰后频率响应形态。然而,目前研究并未清晰刻画出直驱风机参与频率调节主导响应环节,同时存在建模过于复杂而难以适用于频率特性分析的问题。因此,根据空气动力学方程、发电机模型、功率控制环节及其控制电路结构,文中针对两种典型直驱风机,分别推导其惯量控制的线性化模型,认识了电流控制-升压电路/定子电压动态回路的快速物理过程并对其进行合理忽略,发现两种类型直驱风机存在通用的频率响应机制,均可被描述为转速外环-风机转子运动方程的级联作用。进一步地,结合同步机组的频率响应模型,构建了含跟网型直驱风机惯量控制的系统频率分析聚合模型。同时,为适用于频率极值的解析计算,采用平衡截断法将聚合模型降阶为二阶模型。通过MATLAB/Simulink仿真验证了聚合模型及其降阶模型的准确性和适用性,并分析了控制参数和系统状态对频率动态特性和稳定裕度的影响。 展开更多
关键词 跟网型 直驱风机 惯量控制 频率响应 聚合模型 稳定裕度
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中国农村交通基础设施与农民外出务工收入 被引量:1
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作者 刘生龙 李萌 《中国经济问题》 北大核心 2025年第1期137-152,共16页
本文利用2009—2017年中国农村固定观察点微观入户数据,在广义罗伊模型框架下,估计了交通基础设施改善对农村劳动力外出务工的影响。研究发现,连通交通主干线增加了农民外出务工收入。进一步的研究表明农村交通基础设施改善对农民外出... 本文利用2009—2017年中国农村固定观察点微观入户数据,在广义罗伊模型框架下,估计了交通基础设施改善对农村劳动力外出务工的影响。研究发现,连通交通主干线增加了农民外出务工收入。进一步的研究表明农村交通基础设施改善对农民外出务工的影响存在根本的异质性,更容易连接交通主干线的农村地区,连接交通主干线对外出务工收入的影响是负的,而对于交通基础设施可及性越差的农村居民,连通交通主干线会显著增加他们的外出务工收入。通过对未来农村交通基础设施进一步改善的效应进行模拟,发现落后农村地区在连接交通主干线之后外出务工收入会明显增加。 展开更多
关键词 农村基础设施 收入差距 边际处理效应 广义罗伊模型 根本的异质性
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An accurate analytical I-V model for sub-90-nm MOSFETs and its application to read static noise margin modeling
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作者 Behrouz AFZAL Behzad EBRAHIMI +1 位作者 Ali AFZALI-KUSHA Massoud PEDRAM 《Journal of Zhejiang University-Science C(Computers and Electronics)》 SCIE EI 2012年第1期58-70,共13页
We propose an accurate model to describe the I-V characteristics of a sub-90-nm metal-oxide-semiconductor field-effect transistor(MOSFET) in the linear and saturation regions for fast analytical calculation of the cur... We propose an accurate model to describe the I-V characteristics of a sub-90-nm metal-oxide-semiconductor field-effect transistor(MOSFET) in the linear and saturation regions for fast analytical calculation of the current.The model is based on the BSIM3v3 model.Instead of using constant threshold voltage and early voltage,as is assumed in the BSIM3v3 model,we define these voltages as functions of the gate-source voltage.The accuracy of the model is verified by comparison with HSPICE for the 90-,65-,45-,and 32-nm CMOS technologies.The model shows better accuracy than the nth-power and BSIM3v3 models.Then,we use the proposed I-V model to calculate the read static noise margin(SNM) of nano-scale conventional 6T static random-access memory(SRAM) cells with high accuracy.We calculate the read SNM by approximating the inverter transfer voltage characteristic of the cell in the regions where vertices of the maximum square of the butterfly curves are placed.The results for the SNM are also in excellent agreement with those of the HSPICE simulation for 90-,65-,45-,and 32-nm technologies.Verification in the presence of process variations and negative bias temperature instability(NBTI) shows that the model can accurately predict the minimum supply voltage required for a target yield. 展开更多
关键词 modelING NANO-SCALE Process variation Read static noise margin(SNM) SRAM
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考虑源荷随机性及市场机制的省内电力平衡裕度快速评估
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作者 朱柳 唐俊杰 +4 位作者 黄国栋 孙青 王德林 常江 王海云 《电力系统自动化》 北大核心 2025年第9期73-83,共11页
省间电力现货市场在电力余缺互济等方面发挥了重要作用,然而,源荷功率的随机性给其正常运行带来一系列挑战。省内电力平衡裕度作为源荷随机性传递到省间电力现货市场的指标载体及省间市场交易的基本信息,如何对其精确、快速评估成为应... 省间电力现货市场在电力余缺互济等方面发挥了重要作用,然而,源荷功率的随机性给其正常运行带来一系列挑战。省内电力平衡裕度作为源荷随机性传递到省间电力现货市场的指标载体及省间市场交易的基本信息,如何对其精确、快速评估成为应对这些挑战的关键。对此,提出一种考虑源荷随机性及市场机制的省内电力平衡裕度快速评估方法。首先,建立服从任意分布且含相关性的源荷双侧随机性模型;然后,基于预出清机制提出了一种省内电力平衡裕度评估模型,并引入维自适应稀疏混沌多项式展开法以提高其计算效率;最后,通过改进的IEEE RTS-96系统算例验证该方法的有效性。结果表明,相比于传统预出清模型,所提方法可以根据联络线节点组合分配下的省内阻塞风险情况,择优选取交易节点的划分方式,实现最优划分方式下省内电力平衡裕度的准确、快速评估。 展开更多
关键词 电力平衡裕度 随机性 出清 概率建模 维自适应稀疏混沌多项式展开 电力市场
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早期食管癌ESD后水平切缘阳性的列线图预测模型构建及验证
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作者 周娇 师正燕 +2 位作者 朱坤 李俊涛 崔雅清 《检验医学与临床》 2025年第20期2786-2792,共7页
目的基于早期食管癌(EC)内镜黏膜下剥离术(ESD)后水平切缘阳性的独立影响因素构建列线图预测模型,并对其效能进行验证。方法选取2021年4月至2023年4月在该院接受ESD的191例早期EC患者作为研究对象,共201处水平切缘病灶。根据术后病理学... 目的基于早期食管癌(EC)内镜黏膜下剥离术(ESD)后水平切缘阳性的独立影响因素构建列线图预测模型,并对其效能进行验证。方法选取2021年4月至2023年4月在该院接受ESD的191例早期EC患者作为研究对象,共201处水平切缘病灶。根据术后病理学评估结果,将ESD后水平侧切缘阳性的纳入水平切缘阳性组,阴性的纳入水平切缘阴性组。比较2组患者术后病理结果;采用多因素Logistic回归分析早期EC患者术后水平切缘阳性的影响因素,并构建列线图预测模型;绘制受试者工作特征(ROC)曲线、校准曲线和决策分析曲线(DCA)评估列线图预测模型的预测效能、校准度以及临床收益。结果病理结果显示,水平切缘阳性组有39处,水平切缘阴性组有162处;在水平切缘阳性组中,水平切缘为低级别上皮内瘤变累及病灶25处,水平切缘为高级别上皮内瘤变累及病灶12处,水平切缘为癌累及病灶2处。多因素Logistic回归分析结果显示,病变浸润深度为黏膜下层深层(SM2)、病变累及管周≥3/4均为水平切缘阳性的独立危险因素(P<0.05),术中标记前有碘染为水平切缘阳性的独立保护因素(P<0.05)。基于上述影响因素构建列线图预测模型,ROC曲线分析结果显示,列线图预测模型预测早期EC患者ESD后水平切缘阳性的曲线下面积为0.996(95%CI:0.928~1.000)。校正曲线分析结果显示,模型拟合度良好(Hosmer-Lemeshowχ^(2)=5.428,P=0.321)。DCA结果显示,该模型具有良好的阈值概率和临床净收益。结论基于病变浸润深度、病变累及管周范围、术中标记前是否碘染构建的早期EC患者ESD后水平切缘阳性的列线图预测模型具备较高的预测效果和实用价值,可能成为评估EC患者ESD术后水平切缘阳性的有效诊断工具,为制订患者个性化的治疗方案提供一定的参考。 展开更多
关键词 早期食管癌 内镜黏膜下剥离术 水平切缘阳性 列线图预测模型 验证
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青藏高原东南缘营盘金顶北衙盘龙剖面地壳结构与化学成分 被引量:1
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作者 赵志丹 雷杭山 +6 位作者 白志明 刘栋 王珍珍 许博 苗壮 侯增谦 莫宣学 《地学前缘》 北大核心 2025年第6期256-275,共20页
大陆地壳的结构、组成和演化是地球区别于其他星球的独一无二的重要特征和现今地球科学中最重要的科学问题之一。大陆地壳在地球系统各圈层中扮演着极为重要的角色,是岩石圈与地表圈层相互作用的纽带,也是揭示壳幔物质与能量交换、岩浆... 大陆地壳的结构、组成和演化是地球区别于其他星球的独一无二的重要特征和现今地球科学中最重要的科学问题之一。大陆地壳在地球系统各圈层中扮演着极为重要的角色,是岩石圈与地表圈层相互作用的纽带,也是揭示壳幔物质与能量交换、岩浆作用和成矿作用等地质过程的重要场所。研究地壳结构、组成和演化的方法主要包括深部物理探测、岩浆携带的深源包体、古老变质岩基底和岩浆作用反演等方法。本文选择青藏高原东南缘呈北西南东向横穿西南三江造山带扬子克拉通西缘的主要地质单元,西起云南兰坪县营盘,经过兰坪县金顶、鹤庆县北衙,东至昆明盘龙的地壳剖面(简称营盘盘龙),开展了剖面宽度50 km走廊带及其邻区的地壳结构和化学成分研究。从构造上穿越了兰坪思茅地块,横跨金顶矿区、北衙矿区,东至扬子地台西缘。本文基于已有地球物理测深剖面、古老变质岩系、岩浆岩及深源地壳包体和沉积岩盖层的地球化学和年代学数据,应用地球物理、实验岩石学和岩石地球化学资料的联合限制,尝试建立了营盘—盘龙走廊带内各构造单元的地壳岩石组成模型,估算了上、中和下地壳的元素地球化学成分,并探讨了走廊带和邻区各构造单元的地壳演化、构造岩浆成矿作用过程。 展开更多
关键词 地壳结构 岩石组成模型 化学成分 地壳演化 扬子克拉通西缘 青藏高原东南缘
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低碳发展和能源安全边际约束下的黄河流域地区碳达峰分析
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作者 冯宗宪 于珺 《北京工业大学学报(社会科学版)》 北大核心 2025年第6期77-100,共24页
黄河流域地区是中国重要的综合能源基地,在碳达峰过程中,如何在保障国家能源安全前提下实现流域地区低碳发展,具有十分重要的战略意义。引入能源安全边际概念,构建协同分析能源安全保障和低碳发展的理论框架,阐述流域地区保障国家能源... 黄河流域地区是中国重要的综合能源基地,在碳达峰过程中,如何在保障国家能源安全前提下实现流域地区低碳发展,具有十分重要的战略意义。引入能源安全边际概念,构建协同分析能源安全保障和低碳发展的理论框架,阐述流域地区保障国家能源安全和实现低碳发展的现状,代入包含能源安全边际率等变量在内的扩展的STIRPAT模型,探讨流域地区向碳达峰过渡的发展时序问题。结果表明:(1)向碳达峰过渡期内,本地化石能源产出及其安全边际率的提高会增加流域地区CO_(2)排放;随着化石能源结构变动、非化石能源规模替代利用及其安全边际率的快速提高,CO_(2)排放的攀升速度将减缓且峰值会降低;(2)碳达峰向碳中和过渡期内,由于技术进步等因素的影响,流域地区化石能源安全边际与CO_(2)排放之间会逐渐由正相关转向负相关,非化石能源安全边际的大幅度提高会降低CO_(2)排放;(3)流域各省区因CO_(2)排放水平及效率、资源禀赋和经济发展水平等的差异较大,可划分为不同类型,并展现出不同的脱钩特点;(4)基于国家综合能源安全兜底考虑和基准情景下,流域不同省份将分别于2028—2033年先后达峰,并形成不同的达峰路径。通过能源结构的多元化和清洁化,加快能源技术创新和政策引导,促进电力市场化改革,黄河流域地区有望兼顾保障国家能源安全和实现自身低碳发展的双重任务。 展开更多
关键词 黄河流域地区 能源安全边际 碳达峰 扩展的STIRPAT模型 情景分析
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基于相似性分析的爆炸箔起爆器飞片速度模型研究
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作者 雷凡 赵胜超 +3 位作者 王强 朴俊宇 付秋菠 韩冬冬 《火工品》 北大核心 2025年第5期62-69,共8页
为准确预测爆炸箔起爆器(EFI)的飞片速度,解决现有模型缺乏对EFI设计参数的全面考虑,且难以预测相邻参数域中的连续变化,无法支撑裕量建模中的性能敏感度分析和不确定性传递分析问题,本研究基于量纲分析和相似性原理,并结合试验数据,提... 为准确预测爆炸箔起爆器(EFI)的飞片速度,解决现有模型缺乏对EFI设计参数的全面考虑,且难以预测相邻参数域中的连续变化,无法支撑裕量建模中的性能敏感度分析和不确定性传递分析问题,本研究基于量纲分析和相似性原理,并结合试验数据,提出了一种新型的飞片速度模型,该模型将飞片速度特征参量与EFI的设计参量(如炮筒直径、飞片厚度、爆炸箔厚度和宽度等)关联起来。同时,进行了改变爆炸箔参数、飞片参数、炮筒参数以及起爆装置参数等验证试验,结果表明模型预测的飞片速度曲线与试验结果高度一致。本研究提出的飞片速度模型不仅能够服务于裕量建模,还为EFI的设计和优化提供了重要的理论依据。 展开更多
关键词 爆炸箔起爆器 飞片速度 量纲分析 裕量建模
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南海西南次海盆陆缘演化与幕式扩张的岩浆-构造-地层记录 被引量:1
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作者 杨天一 唐勇 +1 位作者 任建业 巢鹏 《地球科学》 北大核心 2025年第1期195-216,共22页
目前对于边缘海背景下被动大陆边缘的形成演化机制仍存在争议,特别是对洋陆转换带的构造特征与形成过程的认识存在明显不足.为了深入探索边缘海背景下南海陆缘与洋陆转换带构造结构与形成演化特征,通过对横跨西南次海盆V型尖端地震剖面... 目前对于边缘海背景下被动大陆边缘的形成演化机制仍存在争议,特别是对洋陆转换带的构造特征与形成过程的认识存在明显不足.为了深入探索边缘海背景下南海陆缘与洋陆转换带构造结构与形成演化特征,通过对横跨西南次海盆V型尖端地震剖面的解释与研究,识别出莫霍面(Moho)、基底和海底3个一级陆缘界面,划分出细颈化域、超伸展域、原洋域等构造单元;进一步精细解释了共轭陆缘盆地充填层序和多期断裂系统,识别出破裂不整合界面Bi,将陆缘盆地同裂陷期层序(Tg-Bi)划分为S1-S5五个层序,建立了西南次海盆V型尖端区域共轭陆缘的构造-地层格架.构造-地层格架中S3/S4层序之间的界面CBi、S4/S5之间的界面POBi分别与陆壳破裂和原洋洋壳Ⅰ的破裂对应,记录了西南次海盆共轭陆缘岩石圈伸展破裂过程中发生的重要构造事件.结合断裂活动性和盆地原型的分析,将西南次海盆共轭陆缘同裂陷期的演化划分为伸展、细颈化、超伸展和原洋洋壳四个阶段,建立了西南次海盆共轭陆缘演化模式.还建立了西南次海盆V型尖端共轭陆缘地壳的“鳄鱼嘴”结构,识别出总宽度达231 km的两期原洋洋壳.结合外缘高地和同破裂层序(S4-S5)研究,提出两期原洋洋壳的发育与西南次海盆的两幕扩张过程相对应,由原洋洋壳构成了同期洋盆的洋陆转换带.揭示了西南次海盆张开过程中岩石圈的伸展破裂机制与洋脊传播过程中幕式扩张作用对陆缘构造、地层和岩浆作用的影响,对于深入研究南海岩石圈的伸展破裂过程、洋陆转换带的成因以及南海被动陆缘形成的动力学机制具有重要意义. 展开更多
关键词 南海 西南次海盆 陆缘演化模式 幕式扩张 原洋洋壳 洋陆转换带 岩浆-构造-地层记录 海洋地质学
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