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Probabilistic seismic inversion based on physics-guided deep mixture density network

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Petroleum Science 2024年第3期21卷 1611-1631页

作者： qian-Hao Sun Zhao-Yun Zong xin Li National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina Laoshan Laboratory Qingdao266580ShandongChina CNOOC Research Institute Ltd. Beijing100028China

Deterministic inversion based on deep learning has been widely utilized in model parameters *** by logging data,seismic data,wavelet and modeling operator,deterministic inversion based on deep learning can establish nonlinear relationships between seismic data and model ***,seismic data lacks low-frequency and contains noise,which increases the non-uniqueness of the *** conventional inversion method based on deep learning can only establish the deterministic relationship between seismic data and parameters,and cannot quantify the uncertainty of *** order to quickly quantify the uncertainty,a physics-guided deep mixture density network(PG-DMDN)is established by combining the mixture density network(MDN)with the deep neural network(DNN).Compared with Bayesian neural network(BNN)and network dropout,PG-DMDN has lower computing cost and shorter training time.A low-frequency model is introduced in the training process of the network to help the network learn the nonlinear relationship between narrowband seismic data and low-frequency *** addition,the block constraints are added to the PG-DMDN framework to improve the horizontal continuity of the inversion *** illustrate the benefits of proposed method,the PG-DMDN is compared with existing semi-supervised inversion *** synthetic data examples of Marmousi II model are utilized to quantify the influence of forward modeling part,low-frequency model,noise and the pseudo-wells number on inversion results,and prove the feasibility and stability of the proposed *** addition,the robustness and generality of the proposed method are verified by the field seismic data.

关键词： Deep learning Probabilistic inversion Physics-guided Deep mixture density network

Influence of static pre-loading on the dynamic bending strength of concrete with particle element modeling

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Science China(Technological Sciences) 2015年第2期58卷 284-296页

作者： WU ming xin ZHANG Chu Han State Key Laboratory of Hydroscience and Engineering Tsinghua University

Experimental tests show that static pre-loading has a significant effect on the dynamic strength of *** on meso-scale particle element model,numerical simulations of dynamic bending tests with pre-loading are *** stress–strain relationships are then *** increase in dynamic strength is found when the pre-loadings are imposed within the elastic limit of ***,when the imposition of pre-loadings reaches the plastic or softening range,dynamic strengths may gradually decrease along with the increase in *** distribution of energy components and the failure modes are discussed to explain the mechanisms of the phenomena.

关键词： concrete static pre-loading dynamic bending strength rate effect particle element modeling

In situ strengths of matrix in a composite

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Acta Mechanica Sinica 2017年第1期33卷 120-131页

作者： Zheng-ming Huang Li-Min xin Key Laboratory of the Ministry of Education for Advanced Civil Engineering Materials School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092 China

A major obstacle to achieving reasonable strength prediction of a composite only from its constituent information is in the determination of in situ strengths of the matrix. One can measure only the original strengths of the pure matrix, on the basis of which the predicted transverse strengths of a unidirectional (UD) composite are far from reality. It is impossible to reliably measure matrix in situ strengths. This paper focuses on the correlation between in situ and original strengths. Stress concentrations in a matrix owing to the introduction of fibers are attributed to the strength variation. Once stress concentration factors (SCFs) are obtained, the matrix in situ strengths are assigned as the original counterparts divided by them. Such an SCF cannot be defined following a classical approach. All of the relevant issues associated with determining it are systematically addressed in this paper. Analytical expressions for SCFs under transverse tension, transverse compression, and transverse shear are derived. Closed-form and compact formulas for all of the uniaxial strengths of a UD composite are first presented in this paper. Their application to strength predictions of a number of typical UD composites demonstrates the correctness of these formulas.

关键词： Composites Strength formulas Micromechanics Stress concentration factor Matrix in situ strength

A rice geranylgeranyl reductase is essential for chloroplast development

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Journal of Integrative Agriculture 2021年第10期20卷 2592-2600页

作者： LIU Xi YI xin YANG Yan-rong HUANG qian-qian Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection/Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake Huaiyin Normal UniversityHuai’an 223300P.R.China

Chloroplasts are essential for plant photosynthesis and *** genes have been identified that regulate plant chloroplast ***,it is not known at a molecular level how these genes regulate chloroplast *** this study,we isolated a mutant ygl2(yellow-green leaf2)that exhibited a pigment-defective ***2 encodes a geranylgeranyl reductase,and in mutant ygl2,there was a single base change(T1361G)located in the third exon of YGL2 that resulted in a missense mutation(L454R)in the encoded *** electron microscopy revealed that chloroplast development was impaired in the ygl2 *** expression levels of plastid-encoded genes were significantly altered in the ygl2 ***,in a yeast two-hybrid assay,we found that YGL2 interacted with the RNA editing factor MORF8.

关键词： rice(Oryza sativa L.) chloroplast YGL2 geranylgeranyl reductase

气相色谱-离子迁移谱技术在食品真实性鉴别中的应用研究进展

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食品科学 2025年第1期46卷 227-236页

作者：张碧莹隋雨萌张鑫李永杰孔保华刘昊天陈倩东北农业大学食品学院黑龙江哈尔滨150030

气相色谱-离子迁移谱是一种灵敏的检测、鉴别和监测不同基质中痕量物质的分析技术,能够通过气相色谱和离子迁移谱对分析物质进行二次快速分离和高精准定性。由于气相色谱-离子迁移谱具有环保、使用便捷、操作简单及适用于工业大量连续... 详细信息

气相色谱-离子迁移谱是一种灵敏的检测、鉴别和监测不同基质中痕量物质的分析技术,能够通过气相色谱和离子迁移谱对分析物质进行二次快速分离和高精准定性。由于气相色谱-离子迁移谱具有环保、使用便捷、操作简单及适用于工业大量连续检测等优点,近年来逐渐成为食品真实性鉴别的热门分析技术。本文主要介绍气相色谱-离子迁移谱的类型、结构、工作原理和分析方法,重点综述其在食品真实性鉴别中的应用,以期为食品真实性问题的解决提供理论参考。

关键词：气相色谱-离子迁移谱真实性鉴别食品应用

Investigations of methane adsorption characteristics on marine-continental transitional shales and gas storage capacity models considering pore evolution

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Petroleum Science 2024年第4期21卷 2273-2286页

作者： Chen-Gang Lu Xian-ming Xiao Zhen-qian Xue Zhang-xin Chen Yin-Tao Dong Yue Feng Gang Li School of Energy Resources China University of Geosciences(Beijing)Beijing100083China School of Civil and Environmental Engineering Nanyang Technological University50 Nanyang Avenue639798Singapore Chemical and Petroleum Engineering University of CalgaryCalgaryAlbertaT2N 1N4Canada Eastern Institute of Technology(tentative) Ningbo315000ZhejiangChina CNOOC Research Institute Beijing100028China

Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological *** the related research of marine shales has been well-illustrated,the methane adsorption of marine-continental transitional(MCT)shales is still *** this study,a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin,*** Ono-Kondo model was used to fit the adsorption data to obtain the adsorption ***,the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon(TOC)content of 1.71%,and the effects of reservoir pressure coefficient and water saturation on GSC were *** experimental results,compared to the composition of the MCT shale,the pore structure dominates the methane adsorption,and meanwhile,the maturity mainly governs the pore ***,maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial *** two parameters,micropore pore volume and non-micropore surface area,induce a good fit for the adsorption capacity data of the *** simulation results,the depth,pressure coefficient,and water saturation of the shale all affect the *** demonstrates a promising shale gas potential of the MCT shale in a deeper block,especially with low water ***,the economic feasibility of shale gas could be a major consideration for the shale with a depth of60%in the Yushe-Wuxiang *** study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas.

关键词： High-pressure methane adsorption Marine-continental transitional shale gas Ono-Kondo model Adsorption thermodynamics Gas storage capacity model

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Communications in Theoretical Physics 2007年第3X期48卷 399-404页

作者： qian Su-Ping TIAN Li-xin Department of Mathematics Changshu Institute of Technology Changshu 215500 China Nonlinear Scientific Research Center Faculty of Science Jiangsu University Zhenjiang 212013 China

Using the direct method for a coupled KdV system, six types of the similarity reductions are obtained. The group explanation of the results is also given. It is pointed out that, in order to find all the results by nonclassical Lie approach, two additional condition equations should be satisfied at the same time together with two original equations.

关键词： coupled KdV equations direct method nonclassical Lie approach

Geochemistry,Zircon U-Pb Age and Hf Isotopic Constraints on the Petrogenesis of the Silurian Rhyolites in the Loei Fold Belt and Their Tectonic Implications

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Journal of Earth Science 2016年第3期27卷 391-402页

作者： Tianyu Zhao xin qian Qinglai Feng State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China School of Earth Sciences China University of GeosciencesWuhan 430074China

Zircon U-Pb dating, Lu-Hf isotopic and geochemical data for the Silurian rhyolites from the Loei fold belt are presented to constrain their petrogenesis and tectonic settings. The rhyolites give a weighted mean 206Pb/238 U age of 423.7±2.7 Ma, and are characterized by high SiO2, Al2O3, K2 O and low MnO, MgO and P2O5. All samples are enriched in LILEs（e.g., Ba, K, Pb） and LREEs and depleted in HFSEs（e.g., Nb, Ta, Ti） with obvious negative Eu-anomalies（δEu=0.56–0.63）. The calc-alkaline rhyolites are typical arc-related rocks. The Loei rhyolites have high A/CNK ratios（1.19–1.34） and positive εHf（t）（4.03–5.38）, which can be interpreted as partial melting of juvenile crustal materials followed by multistage melting and differentiation, similar to highly fractional I-type rocks. Combined with regional geological surveys, the Loei rhyolites should be formed in a volcanic arc environment and may be in contact with the Truong Son fold belt during the Early Paleozoic. Moreover, the Simao Block might be in contiguity with the Indochina Block during Silurian.

关键词： I-type rhyolite zircon U-Pb dating Hf isotopic composition geochemical characteristics Loei fold belt Indochina Block

Pullback Attractors for a 3D Non-autonomous Navier-Stokes-Voight Equations

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Acta Mathematicae Applicatae Sinica 2019年第4期35卷 737-752页

作者： Yu-ming QIN xin-guang YANG xin LIU Department of Applied Mathematics Donghua University Shanghai 201620 China Department of Mathematics and Information Science Henan Normal University Xinxiang 453007 China School of Information Science and Technology Donghua University Shanghai 201620 China Department of Applied Mathematics School of Statistics and Information Shanghai University of International Business and Economics Shanghai 201620 China

This paper is concerned with the existence of pullback attractors for the three dimensional nonautonomous Navier-Stokes-Voight equations for the processes generated by the weak and strong solutions. The main difficulty is how to establish the pullback asymptotic compactness via energy equation approach under suitable assumption on external force.

关键词： Navier-Stokes-Voight equations processes pullback attractor