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A semi-analytical pressure and rate transient analysis model for inner boundary and propped fractures exhibiting dynamic behavior under long-term production conditions

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Petroleum Science 2024年第4期21卷 2520-2535页

作者： Lin-Song Cheng Chong Cao Quan-Yu Pan Pin Jia Ren-Yi Cao Zhi-Kai Wang jun-jie shi College of Petroleum Engineering China University of Petroleum (Beijing) Sinopec Petroleum Exploration and Production Research Institute CNOOC Research Institute State Key Laboratory of Water Resources Protection and Utilization in Coal Mining

The loss of hydrocarbon production caused by the dynamic behavior of the inner boundary and propped fractures under long-term production conditions has been widely reported in recent studies. However,the quantitative relationships for the variations of the inner boundary and propped fractures have not been determined and incorporated in the semi-analytical models for the pressure and rate transient analysis. This work focuses on describing the variations of the inner boundary and propped fractures and capturing the typical characteristics from the pressure transient curves.A generalized semi-analytical model was developed to characterize the dynamic behavior of the inner boundary and propped fractures under long-term production conditions. The pressure-dependent length shrinkage coefficients, which quantify the length changes of the inner zone and propped fractures, are modified and incorporated into this multi-zone semi-analytical model. With simultaneous numerical iterations and numerical inversions in Laplace and real-time space, the transient solutions to pressure and rate behavior are determined in just a few seconds. The dynamic behavior of the inner boundary and propped fractures on transient pressure curves is divided into five periods: fracture bilinear flow(FR1),dynamic PFs flow(FR2), inner-area linear flow(FR3), dynamic inner boundary flow(FR4), and outer-area dominated linear flow(FR5). The early hump during FR2 period and a positive upward shift during FR4period are captured on the log-log pressure transient curves, reflecting the dynamic behavior of the inner boundary and propped fractures during the long-term production *** transient pressure behavior will exhibit greater positive upward trend and the flow rate will be lower with the shrinkage of the inner boundary. The pressure derivative curve will be upward earlier as the inner boundary shrinks more rapidly. The lower permeability caused by the closure of un-propped fractures in the inner zo

关键词： Semi-analytical model Length shrinkage Dynamic behavior Boundary changes Transient behavior

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Rectangling irregular videos by optimal spatio-temporal warping

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Computational Visual Media 2022年第1期8卷 93-103页

作者： Jin-Liang Wu jun-jie shi Lei Zhang The 54th Research Institute of CETC Shijiazhuang 050050China School of Computer Science Beijing Institute of TechnologyBeijing 100081China.

Image and video processing based on geometric principles typically changes the rectangular shape of video frames to an irregular shape. This paper presents a warping based approach for rectangling such irregular frame boundaries in space and time, i.e., making them rectangular again. To reduce geometric distortion in the rectangling process, we employ contentpreserving deformation of a mesh grid with line structures as constraints to warp the frames. To conform to the original inter-frame motion, we keep feature trajectory distribution as constraints during motion compensation to ensure stability after warping the frames. Such spatially and temporally optimized warps enable the output of regular rectangular boundaries for the video frames with low geometric distortion and jitter. Our experiments demonstrate that our approach can generate plausible video rectangling results in a variety of applications.

关键词： rectangling warping content-preserving

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Inclusions and solidification structures of high pure ferritic stainless steels dual stabilized by niobium and titanium

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Rare Metals 2014年第6期33卷 761-766页

作者： Hong-Po Wang Li-Feng Sun jun-jie shi Cheng-jun Liu Mao-Fa Jiang Chi Zhang Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education) Northeastern University

As the raw materials in the post process of rolling and heat treatment, ingots have great effects on the properties of the final products. Inclusions and solidification structures are the most important aspects of the quality of ingots. Niobium and titanium are usually used to react with carbon and nitrogen to improve the properties of ferritic stainless steels. In this research, combined with thermodynamic calculation, effects of niobium and titanium on the inclusions and solidification structures in three kinds of high pure ferritic stainless steels with different titanium additions were investigated by optical microscope（OM）, scanning electron microscope（SEM）, transmission electron microscope（TEM）, and energy disperse spectrometer（EDS）. Results show that Al2O3 and a few（Nb,Ti）N particles form when titanium addition is 0.01 %.Furthermore, inclusions are mainly Ti N and Al2O3–Ti Ox–Ti N duplex inclusions when titanium addition is more than0.10 %. Those two types of inclusions are in well distribution, and can afford nuclei to the solidification ***, the ratio of equiaxed zone increases with the increase of titanium addition. The ratio increases from42.1 % to 64.0 % with the titanium addition increasing from 0.01 % to 0.10 %, and it increases to 85.7 % when the titanium addition reaches 0.34 %.

关键词： High pure ferritic stainless steel Inclusion Solidification structure Equiaxed zone Stabilization element

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Large eddy simulation of cavitating flows with dynamic adaptive mesh refinement using OpenFOAM

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Journal of Hydrodynamics 2020年第2期32卷 398-409页

作者： Lin-min Li Dai-qing Hu Yu-cheng Liu Bi-tao Wang Chen shi jun-jie shi Chang Xu College of Energy and Electrical Engineering Hohai UniversityNanjing211100China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Anhui Jinzhai Pumped Storage Power Co. LtdLu’an237300China

Cavitating flows are dominated by large gradients of physical properties and quantities containing complicated interfacial structures and lots of multi-scale eddies that need to be accurately characterized using a high-resolution *** present work,within OpenFOAM,proposes an effective modeling framework using the large eddy simulation(LES)approach along with the volume of fluid(VOF)method to simulate the two-phase flow system and applies the Schnerr-Sauer model to calculate the mass-transfer rate between water and *** adaptive mesh refinement(AMR)which is a powerful tool for allocating high-resolution grids only to the region of the greatest concern is adopted for improving the solution of interfacial *** effect of grid size is firstly investigated and the time-averaged quantities are verified against the experimental data,and then simulations of cavitating flows are successfully achieved to precisely characterize the features of cavitation with automatically and dynamically refining the *** the refinement only takes place in the interfacial region,high-precision simulations can be achieved with limited computational resources,and the method shows promising prospects for modeling of the multi-scale,time-critical and computationally intensive cavitating flows.

关键词： Cavitating flows large eddy simulation(LES) multi-scale adaptive mesh refinement(AMR) OpenFOAM

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Sequential enantioselective Ugi-4CR/post-Ugi transformation strategy:a precise construction of structurally diverse azaspiro polycyclic scaffolds

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Science China Chemistry 2024年第2期67卷 576-586页

作者： Xiao-Bao Wu jun-Xiu shi Yi-Ming Ou Hua-jie Jiang Yi-jun Fang Qi-Ming Wang Quan Gao jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and ApplicationAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefei230036China

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic *** diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results(up to 99:1 e.r.,>95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(Ⅲ) complexes.

关键词： asymmetric catalysis post-Ugi transformation anionic stereogenic-at-cobalt(Ⅲ)complex azaspiro polycyclic scaffold one-pot synthesis

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De novo Synthesis of Chiral 3,4-Dihydroquinazolines via One-Pot Enantioselective Ugi-Azide/Cyclization Sequences

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Chinese Journal of Chemistry 2024年第18期42卷 2140-2146页

作者： Zu-Kui Xie jun-jun Ding Yi-Ming Ou jun-Xiu shi Meng-Lan Shen Chuan-Zhi Yao Hua-jie Jiang jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and Applicationand Anhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefeiAnhui 230036China

Background and Originality Content,3,4-Dihydroquinazoline frameworks have frequently been encountered in natural products and bioactive *** the past decades,these key structures prompted the development of creative pharmaceuticals owing to their prominent biological properties,including trypanothione reductase(TryR)inhibitor,Hepatitis B virus(HBV)inhibitive activities,anticancer activities,etc.(Scheme 1A).[1]Notably,the chirality of the C4 atom is crucial for drug *** example,the DPC-083 is a potent reverse transcriptase inhibitor for the treatment of HIV infection but the undesired enantiomers exhibit virtually no activity.[ia]Therefore,developing synthetic methods for innovative chiral 4-substituted 3,4-dihydroquinazolines is significant and essential for drug discovery.

关键词： Anionic stereogenic-at-cobalt(ll)complex De novo synthesis post-Ugi transformation One-pot sequence Asymmetric synthesis Multicomponentreactions

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Effect of electrical parameters and slag system on macrostructure of electroslag ingot

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China Foundry 2024年第1期21卷 44-50页

作者： Bing-jie Wang Yu Wang Meng-jun Wang Lei Zhao Li-zhong Chang Xiao-fang shi School of Metallurgy engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina

To investigate the influence of electric parameters and slag system on the solidification quality of electroslag ingot during electroslag remelting,different power supply modes,current strengths and remelting slag systems were used to conduct electroslag remelting experiments on 304L austenitic stainless steel,and the macrostructure of electroslag ingots was *** results indicate that the depth of the metal pool decreases with the reduction of remelting frequency in the low frequency power supply *** effects of different power supply modes,such as low-frequency,direct current straight polarity(DCSP),and direct current reverse polarity(DCRP),on reducing the depth of the metal pool increase in that *** reducing the remelting current strength in the same power supply mode,the depth of metal pool is *** compared to the binary slag system of 70%CaF2+30%Al2O3,the ternary slag system of 60%CaF2+20%Al2O3+20%CaO is more effective in reducing the depth of the metal pool during *** the 60%CaF2+20%Al2O3+20%CaO ternary slag system results in a shallower and flatter metal pool,with columnar crystal growth occurring closer to the axial *** effect is observed for both low frequency and direct current(DC)power supply modes.

关键词： electroslag remelting frequency slag system solidification quality

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Theory and test of underground explosions:Coupling rule between cratering and ground shock

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Underground Space 2024年第4期17卷 146-160页

作者： Wei Guo jie Li Benjun shi Tianhan Xu Xiaohui Xu Gan Li jie shi State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact Army Engineering University of PLANanjing 210007China

Calculating the parameters of the ground shock induced by an underground explosion is a complex energy coupling *** is difficult to establish a unified ground shock coupling law from limited test *** paper summarizes the research results obtained at home and abroad and systematically analyzes the coupling mechanism of craters formed by an underground explosion and the ground *** differences between the concepts of"closed-explosion critical depth"and"equivalent closed-explosion critical depth"are clearly *** spreading of the ground shock energy is attributed to the explosive expansion of the air cavity,revealing a linear relationship between the volume of the cavity region(or the volume of the crack region)and the ground shock energy associated with the underground *** proportionality factor is related to the mechanical properties of the medium and is independent of the magnitude of the explosion *** on this,a theoretical calculation formula and conversion method for the ground shock coupling coefficient were *** tests were conducted in clay and Plexiglass under varying burial *** test results were consistent with the theoretically calculated *** study provides a theoretical basis for the design of explosion-resistant structures in underground engineering.

关键词： Underground explosion Ground shock coupling Coupling coefficient Equivalent closed explosion Experimental study

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Subsurface multi-physical characterization of mountain excavation and city construction in loess plateau with a fiber-optic sensing system

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2935-2946页

作者： jie Liu Bin shi Kai Gu Meng-Ya Sun jun-Cheng Yao He-Ming Han School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu210023China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing210023China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China

Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial *** the subsurface evolution characteristics of the artificial land is essential,yet ***,we use an improved fiber-optic monitoring system for its subsurface multi-physical *** system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and ***’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long *** reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact ***,the filling loess exhibits a stronger creep capability compared to underlying intact *** deformation along the profile is unevenly distributed,with a positive correlation with soil *** accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant ***,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,*** refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.

关键词： Mountain excavation and city construction Fiber-optic monitoring Multi-physical characterization Compacted loess

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A modern survey method for determining live loads based on multi-source and open-access data on the Internet

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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1135-1147页

作者： Chi XU jun CHEN jie LI School of Civil Engineering Tongji UniversityShanghai 200092China The State Key Laboratory on Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

Sufficient survey data are required to describe the stochastic behaviors of live ***,due to manual and on-site operation required by traditional survey methods,traditional surveys face challenges like occupant resistance,high costs,and long implementation *** study proposes a new survey method to access live load data online and *** samples are acquired from multi-source,open-access and dynamically updated data on the *** change intervals,geometrical dimensions and object quantities are obtained from transaction information,building attributes and virtual reality models on real estate websites,*** object weights are collected from commodity information on e-commerce *** integration of the aforementioned data allows for the extraction of necessary statistics to describe a live load *** proposed method is applied to a live load survey in China,covering 20040 m^(2),with around 90000 samples acquired for object weights and load *** survey results reveal that about 70%−80%of the amplitude statistics are attributable to 1/6 of the total object types.

关键词： live load online survey method data acquisition data integration

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