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Numerical well test for well with finite conductivity vertical fracture in coalbed

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Applied Mathematics and Mechanics(English Edition) 2014年第6期35卷 729-740页

作者：刘曰武欧阳伟平赵培华鹿倩方惠军 Institute of Mechanics Chinese Academy of Sciences PetroChina Coalbed Methane Company Limited Well Test Department of Geermu Oil Factory of Qinghai Oil Field

A new well test model is developed for the hydraulic fractured well in coalbed by considering the following aspects： methane desorption phenomena, finite conductivity vertical fractures, and asymmetry of the fracture about the well. A new parameter is introduced to describe the storage of the fracture, which is named as a combined fracture storage. Another new concept called the fracture asymmetry coefficient is used to define the asymmetry of the fracture about the well. Finite element method （FEM） is used to solve the new mathematical model. The well test type curves and pressure fields are obtained and analyzed. The effects of the combined fracture storage, desorption factor, fracture conductivity, and fracture asymmetry coefficient on the well test type curves are discussed in detail. In order to verify the new model, a set of field well test data is analyzed.

关键词： combed fractured well numerical method finite element method (FEM) finite conductivity

Dynamic process simulation with a Savage-Hutter type model for the intrusion of landslide into river

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Journal of Mountain Science 2016年第7期13卷 1265-1274页

作者： LIU wei He Si-ming ou yang Chao-jun Key laboratory of Mountain Hazards and Surface Process Chinese Academy of Science Institute of Mountain Hazards and Environment Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences

Natural damming of rivers by mass movements is a very common and potentially dangerous phenomena which has been documented all over the world. In this paper, a two-layer model of Savage-Hutter type is presented to simulate the dynamic procedure for the intrusion of landslide into rivers. The two-layer shallow water system is derived by depth averaging the incompressible Navier-Stokes equations with the hydrostatic assumption. A high order accuracy scheme based on the finite volume method is proposed to solve the presented model equations. Several numerical tests are performed to verify the realiability and feasibility of the proposed model. The numerical results indicate that the proposed method can be competent for simulating the dynamic process of landslide intrusion into the river. The interaction effect between both layers has a significant impact on the landslide movement, water fluctuation and wave propagation.

关键词： Landslide Two-layer model Savage Hutter type Numerical simulation

A Video Captioning Method by Semantic Topic-Guided Generation

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Computers, Materials & Continua 2024年第1期78卷 1071-1093页

作者： ou Ye Xinli wei Zhenhua Yu Yan Fu Ying yang College of Computer Science and Technology Xi’an University of Science and TechnologyXi’an710054China

In the video captioning methods based on an encoder-decoder,limited visual features are extracted by an encoder,and a natural sentence of the video content is generated using a ***,this kind ofmethod is dependent on a single video input source and few visual labels,and there is a problem with semantic alignment between video contents and generated natural sentences,which are not suitable for accurately comprehending and describing the video *** address this issue,this paper proposes a video captioning method by semantic topic-guided ***,a 3D convolutional neural network is utilized to extract the spatiotemporal features of videos during the ***,the semantic topics of video data are extracted using the visual labels retrieved from similar video *** the decoding,a decoder is constructed by combining a novel Enhance-TopK sampling algorithm with a Generative Pre-trained Transformer-2 deep neural network,which decreases the influence of“deviation”in the semantic mapping process between videos and texts by jointly decoding a baseline and semantic topics of video *** this process,the designed Enhance-TopK sampling algorithm can alleviate a long-tail problem by dynamically adjusting the probability distribution of the predicted ***,the experiments are conducted on two publicly used Microsoft Research Video Description andMicrosoft Research-Video to Text *** experimental results demonstrate that the proposed method outperforms several state-of-art ***,the performance indicators Bilingual Evaluation Understudy,Metric for Evaluation of Translation with Explicit Ordering,Recall Oriented Understudy for Gisting Evaluation-longest common subsequence,and Consensus-based Image Description Evaluation of the proposed method are improved by 1.2%,0.1%,0.3%,and 2.4% on the Microsoft Research Video Description dataset,and 0.1%,1.0%,0.1%,and 2.8% on the Microsoft Research-Video to Text dataset

关键词： Video captioning encoder-decoder semantic topic jointly decoding Enhance-TopK sampling

A new method for early detection of myocardial ischemia:cardiodynamicsgram(CDG)

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Science China(Information Sciences) 2016年第1期59卷 95-105页

作者： Cong WANG Xunde DONG Shanxing ou wei WANG Junmin HU Feifei yang College of Automation Science and Engineering South China University of Technology Department of Radiology General Hospital of Guangzhou Military Command Department 5 of Gerontology General Hospital of Guangzhou Military Command

Early detection of myocardial ischemia via electrocardiographic methods is important and challenging. In the study, based on the standard 12-lead electrocardiography(ECG), a new method called cardiodynamicsgram(CDG) is proposed for early detection of myocardial ischemia. Using a recently proposed deterministic learning algorithm, the cardiodynamics information is extracted from the ST-T segments of standard 12-lead ECG. The CDG is generated by plotting the three-dimensional cardiodynamics information. By analyzing CDG morphology, it is found that significant correlations exist between CDG and ischemia. By evaluating ischemia patients and healthy controls from the Physikalisch-Technische Bundesanstalt(PTB) database and the General Hospital of Guangzhou Military Command, the CDG method achieves a mean sensitivity of 90.3% and a mean specificity of 87.8%, which are higher than those of both the standard 12-lead ECG and the exercise ECG. As it is noninvasive, convenient, and inexpensive, it is hopeful that CDG may become a cost-effective screening method for early detection of ischemic heart diseases.

关键词： early detection myocardial ischemia cardiodynamicsgram(CDG) ECG deterministic learning cardiodynamics

Amides as surrogates of aldehydes for C–C bond formation:amide-based direct Knoevenagel-type condensation reaction and related reactions

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Science China Chemistry 2020年第1期63卷 11-15页

作者： wei ou Pei-Qiang Huang Department of Chemistry Fujian Provincial Key Laboratory of Chemical Biology College of Chemistry and Chemical Engineering Xiamen University

Aldehydes are perhaps the most versatile compounds that enable many C-C bond forming reactions,which are not amenable for other subclasses of carbonyl *** report the first use of amides as surrogates of aldehydes for C-C bond formation,namely,the direct Knoevenagel-type condensation based on *** one-pot method consists of controlled reduction of an amide with LDBIPA[LiAlH(iBu)2(OiPr)],Lewis acid-mediated release of a reactive iminium ion intermediate,nucleophilic addition,and in situ elimination of *** reaction shows good functional group *** also demonstrated that the Schwartz reagent could be used as an alternative of *** employment of nitromethane and a silyl enol ether as the nucleophiles opens an avenue for the unprecedented amide-based nitro-aldol condensation reaction and aldol condensation reaction,respectively.

关键词： amides Knoevenagel condensation C–C bond formation one-pot reaction amide transformation

Exploring drivers of the aggravated surface O_(3) over North China Plain in summer of 2015–2019: Aerosols, precursors, and meteorology

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Journal of Environmental Sciences 2023年第5期127卷 453-464页

作者： Shengju ou wei wei Shuiyuan Cheng Bin Cai Key Laboratory of Beijing on Regional Air Pollution Control Faculty of Environment and LifeBeijing University of TechnologyBeijing 100124China

Continuous aggravated surface O_(3) over North China Plain(NCP)has attracted widely public ***,we evaluated the effects of changes in aerosols,precursor emissions,and meteorology on O_(3) in summer(June)of 2015–2019 over NCP via 8 scenarios with WRF-Chem *** simulated mean MDA8 O_(3) in urban areas of 13 major cities in NCP increased by 17.1%∼34.8%,which matched well with the observations(10.8%∼33.1%).Meanwhile,the model could faithfully reproduce the changes in aerosol loads,precursors,and meteorological conditions.A relatively-even O_(3) increase(+1.2%∼+3.9%for 24-h O_(3) and+1.0%∼+3.8%for MDA8 O_(3))was induced by PM_(2.5) dropping,which was consistent with the geographic distribution of regional PM_(2.5) ***,the NO_(2) reduction coupled with a nearconstant VOCs led to the elevated VOCs/NOx ratios,and then caused O_(3) rising in the areas under VOCs-limited ***,the pronounced increases occurred in Handan,Xingtai,Shijiazhuang,Tangshan,and Langfang(+10.7%∼+13.6%for 24-h O_(3) and+10.2%∼+12.2%forMDA8 O_(3));while the increases in other citieswere 5.7%∼10.5%for 24-h O_(3) and 4.9%∼9.2%for MDA8 O_(3).Besides,the meteorological fluctuations brought about the more noticeable O_(3) increases in northern parts(+12.5%∼+13.5%for 24-h O_(3) and+11.2%∼+12.4%for MDA8 O_(3))than those in southern and central parts(+3.2%∼+9.3%for 24-h O_(3) and+3.7%∼+8.8%for MDA8 O_(3)).The sum of the impacts of the three drivers reached 16.7%∼21.9%,which were comparable to the changes of the observed O_(3).Therefore,exploring reasonable emissionsreduction strategies is essential for the ozone pollution mitigation over this region.

关键词： Surface ozone Driving force Aerosols Precursors Meteorology WRF-Chem model

The integration of dinitropyrazole and 1,3,4-oxadiazole:A novel hybrid heterocyclic skeleton for balancing energy and stability

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Defence Technology（防务技术） 2023年第6期24卷 122-128页

作者： Xiao-xiao Zheng Ting-ou Yan Lei Qian Hong-wei yang Guang-bin Cheng School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing210094China

In this study,a new energetic hybrid skeleton was constructed through the integration of nitropyrazole and 1,3,4-oxadiazole skeletons in a ***,the energetic precursor(2),the azo-bridged compound(3),the neutral nitramine(4)and the corresponding energetic salts(5-7)were *** physicochemical and energetic properties we re experimentally and theo retically *** the developed compounds,the azo-bridged compound(3)and dihydroxylammoinium(6)display high detonation performances(3,D_(v)=8904 m/s,P=34.47 GPa;6,D_(v)=9025 m/s,P=34.66 GPa),moderate sensitivities(3,IS=16 J,FS=120 N;6,IS=20 J,FS=312 N)and good densities(3,1.87 g/cm^(3);6,1.81 g/cm^(3)),which indicates that they have the potential to replace the traditional high-energy explosive *** results show that the integration of different energetic skeletons can achieve a good balance between energy and sensitivity.

关键词： Heterocycle Azo-bridged Hybrid skeletons Energetic materials

Online Magnetic Flux Leakage Detection System for Sucker Rod Defects Based on LabVIEW Programming

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Computers, Materials & Continua 2019年第2期58卷 529-544页

作者： ou Zhang Xueye wei School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing100044China

Aiming at the detection of the sucker rod defects,a real-time detection system is designed using the non-destructive testing technology of magnetic flux leakage(MFL).An MFL measurement system consists of many parts,and this study focuses on the signal acquisition and processing *** of all,this paper introduces the hardware part of the acquisition system in detail,including the selection of the Hall-effect sensor,the design of the signal conditioning circuit,and the working process of the single chip computer(SCM)control serial *** on LabVIEW,a graphical programming software,the software part of the acquisition system is written,including serial port parameter configuration,detection signal recognition,original signal filtering,real-time display,data storage and ***,an experimental platform for the MFL detection is set up,and the MFL measurement is carried out on the transverse and longitudinal defects of the sucker rod *** experimental result shows that the designed acquisition and processing system has good detection performance,simple design and high flexibility.

关键词： flux leakage testing real-time detection sucker rod LabVIEW acquisition and processing

Recent Progress on Flexible Room-Temperature Gas Sensors Based on Metal Oxide Semiconductor

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Nano-Micro Letters 2022年第12期14卷 310-351页

作者： Lang-Xi ou Meng-yang Liu Li-Yuan Zhu David wei Zhang Hong-Liang Lu State Key Laboratory of ASIC and System Shanghai Institute of Intelligent Electronics&SystemsSchool of MicroelectronicsFudan UniversityShanghai 200433People’s Republic of China Yiwu Research Institute of Fudan University Chengbei RoadYiwu City 322000ZhejiangPeople’s Republic of China

With the rapid development of the Internet of Things,there is a great demand for portable gas *** oxide semiconductors(MOS)are one of the most traditional and well-studied gas sensing materials and have been widely used to prepare various commercial gas ***,it is limited by high operating *** current research works are directed towards fabricating high-performance flexible room-temperature(FRT)gas sensors,which are effective in simplifying the structure of MOS-based sensors,reducing power consumption,and expanding the application of portable *** article presents the recent research progress of MOS-based FRT gas sensors in terms of sensing mechanism,performance,flexibility characteristics,and *** review comprehensively summarizes and discusses five types of MOS-based FRT gas sensors,including pristine MOS,noble metal nanoparticles modified MOS,organic polymers modified MOS,carbon-based materials(carbon nanotubes and graphene derivatives)modified MOS,and two-dimensional transition metal dichalcogenides materials modified *** effect of light-illuminated to improve gas sensing performance is further ***,the applications and future perspectives of FRT gas sensors are also discussed.

关键词： Metal oxide semiconductor Flexible gas sensor Room temperature Nanomaterials