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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

Study on a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding

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Advances in Manufacturing 2024年第2期12卷 288-299页

作者： Zhao-Qing Zhang Kai-Ning shi Yao-Yao shi Yi-Hui song Zhe He Ya-song Pu School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an710072People’s Republic of China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an710072People’s Republic of China Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an710072People’s Republic of China

Profile grinding is the most crucial method for the ultra-precision machining of special-shaped ***,profile grinding produces a unique machining profile,and many random factors in the machining process lead to complex surface *** this study,the structural and probabilistic characteristics of the profile grinding of a special-shaped surface were analyzed,and a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding was *** forming process of a GH738 blade tenon tooth surface was considered as an example to demonstrate the *** comparison results showed that the simulation results had similar surface characteristics to the measurement results,and the relative error range of the 3D roughness parameter was 0.21%–19.76%,indicating an accurate prediction and characterization of the complex special-shaped surface under the action of multiple factors.

关键词： Special-shaped surface Profile grinding Surface morphology 3D characterization

Pressure transient characteristics of non-uniform conductivity fractured wells in viscoelasticity polymer flooding based on oil-water two-phase flow

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Petroleum Science 2024年第1期21卷 343-351页

作者： Yang Wang jia Zhang shi-Long Yang Ze-Xuan Xu shi-Qing Cheng National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China

Polymer flooding in fractured wells has been extensively applied in oilfields to enhance oil *** contrast to water,polymer solution exhibits non-Newtonian and nonlinear behavior such as effects of shear thinning and shear thickening,polymer convection,diffusion,adsorption retention,inaccessible pore volume and reduced effective ***,the flux density and fracture conductivity along the hydraulic fracture are generally non-uniform due to the effects of pressure distribution,formation damage,and proppant *** this paper,we present an oil-water two-phase flow model that captures these complex non-Newtonian and nonlinear behavior,and non-uniform fracture characteristics in fractured polymer *** hydraulic fracture is firstly divided into two parts:high-conductivity fracture near the wellbore and low-conductivity fracture in the far-wellbore section.A hybrid grid system,including perpendicular bisection(PEBI)and Cartesian grid,is applied to discrete the partial differential flow equations,and the local grid refinement method is applied in the near-wellbore region to accurately calculate the pressure distribution and shear rate of polymer *** combination of polymer behavior characterizations and numerical flow simulations are applied,resulting in the calculation for the distribution of water saturation,polymer concentration and reservoir *** with the polymer flooding well with uniform fracture conductivity,this non-uniform fracture conductivity model exhibits the larger pressure difference,and the shorter bilinear flow period due to the decrease of fracture flow ability in the far-wellbore *** field case of the fall-off test demonstrates that the proposed method characterizes fracture characteristics more accurately,and yields fracture half-lengths that better match engineering reality,enabling a quantitative segmented characterization of the near-wellbore section with high fracture conductivity and th

关键词： Polymer flooding Non-Newtonian fluid Non-uniform fracture conductivity Two-phase flow Pressure transient analysis

Hierarchical multihead self-attention for time-series-based fault diagnosis

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Chinese Journal of Chemical Engineering 2024年第6期70卷 104-117页

作者： Chengtian Wang Hongbo shi Bing song Yang Tao Key Laboratory of Smart Manufacturing in Energy Chemical Process of the Ministry of Education East China University of Science and TechnologyShanghai 200237China

Fault diagnosis is important for maintaining the safety and effectiveness of chemical *** the multivariate,nonlinear,and dynamic characteristic of chemical process,many time-series-based data-driven fault diagnosis methods have been developed in recent ***,the existing methods have the problem of long-term dependency and are difficult to train due to the sequential way of *** overcome these problems,a novel fault diagnosis method based on time-series and the hierarchical multihead self-attention(HMSAN)is proposed for chemical ***,a sliding window strategy is adopted to construct the normalized time-series ***,the HMSAN is developed to extract the time-relevant features from the time-series process *** improves the basic self-attention model in both width and *** the multihead structure,the HMSAN can pay attention to different aspects of the complicated chemical process and obtain the global dynamic ***,the multiple heads in parallel lead to redundant information,which cannot improve the diagnosis *** the hierarchical structure,the redundant information is reduced and the deep local time-related features are further ***,a novel many-to-one training strategy is introduced for HMSAN to simplify the training procedure and capture the long-term ***,the effectiveness of the proposed method is demonstrated by two chemical *** experimental results show that the proposed method achieves a great performance on time-series industrial data and outperforms the state-of-the-art approaches.

关键词： Self-attention mechanism Deep learning Chemical process Time-series Fault diagnosis

Prognostic factors for lacrimal gland adenoid cystic carcinoma:a retrospective study in Chinese patients

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International Journal of Ophthalmology(English edition) 2024年第8期17卷 1423-1430页

作者： Lu-Di Yang shi-Chong jia Jie Yang Xin song Ye-Fei Wang Xian-Qun Fan Department of Ophthalmology Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai 200011China Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology Shanghai 200011China Tianjin Eye Hospital Tianjin Key Lab of Ophthalmology and Visual ScienceNankai University Affiliated Eye HospitalTianjin Eye InstituteTianjin 300074China

AIM:To explore the prognostic factors for lacrimal gland adenoid cystic carcinoma(LGACC)in Chinese ***:Clinical and histopathological data were reviewed in patients with pathologically confirmed *** recurrence,metastasis,and disease-specific death were the main outcome *** and multivariate analyses were performed by the Kaplan-Meier method and a Cox proportional hazard ***:This retrospective cohort study included 45 patients with pathologically confirmed LGACC between January 2008 and June ***(T)classification(P=0.005),nodal metastasis(N)classification(P=0.018)and positive margin(P=0.008)were independent risk factors of recurrence;T(P=0.013)and N(P=0.003)classification and the basaloid tumor type(P=0.032)were independent risk factors for metastasis;T classification(P<0.001)was an independent factor of death of *** the further analysis,the durations from first surgery to radiotherapy is correlated with metastatic risk in LGACC patients with basaloid component(P=0.022).CONCLUSION:Histological subtype should be emphasized when evaluating prognosis and guiding *** radiotherapy may reduce the risk of metastasis in patients with basaloid component.

关键词： lacrimal gland adenoid cystic carcinoma risk factors prognostic analysis histological subtypes

Regulation and application of supramolecular gel with circularly polarized luminescence

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Science China Chemistry 2024年第6期67卷 1865-1880页

作者： Shen song Yulong shi Liangliang Zhu Bingbing Yue School of Materials and Chemistry&Institute of Bismuth and Rhenium University of Shanghai for Science and TechnologyShanghai200093China State Key Laboratory of Molecular Engineering of Polymers Fudan UniversityShanghai200438China

Supermolecular gel is a three-dimensional network structure assembled by small molecules or polymers in solvents through noncovalent *** emergence of system complexity occurs spontaneously during the molecular self-assembly process.A multitude of chiral molecular self-assembly systems have been engineered,facilitating the achievement of circularly polarized luminescence(CPL)through the amalgamation of chiral entities with *** bonding,π-πstacking,and noncovalent forces,such as host-guest interactions and Van der Waals'forces,confer upon supramolecular gels the capacity to react to diverse *** to the flexibility of supramolecular assembly,the CPL properties of supramolecular gels have rich controllability and can be used in various *** this review,we summarized the examples of CPL-active supramolecular gel assembly,and further summarized the assembly environment factors and external ***,the versatility of CPL applications in supramolecular gels is demonstrated,ranging from optical devices,information encryption,biosensing and chemical sensing,and other practical *** conclusion,the study provides insights into the multicultural factors influencing CPL in supramolecular gels,describes their applications in various domains,and presents future perspectives in the field.

关键词： supramolecular gels circularly polarized luminescence self-assembly chirality stimuli-response

Influence of Heat-setting Temperature on the Microporous Structure and Properties of PP/HDPE Bilayer Microporous Membranes

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Chinese Journal of Polymer Science 2024年第8期42卷 1243-1252页

作者： Jie Xie Yong-shi Wu jia-Yi Xie Rui-Jie Xu Cai-Hong Lei Sai-Nan song Guang-Quan Li An-Ping Huang School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China Lanzhou Petrochemical Research Center Petrochemical Research InsititutePetroChinaLanzhou 730060China School of Chemistry and Civil Engineering Shaoguan CollegeShaoguan 512005China

Due to the mechanical stability of PP layer,the PP/HDPE double-layer microporous mem brane could be prepared at a higher heat-setting temperatu re than that of PE monolayer *** this work,the effects of heat-setting temperature on the pore structure and properties of PP/HDPE dou ble-layer membrane were *** the increase of heat-setting temperature from 120℃to 130℃,the length of connecting bridge crystal and crystallinity in the PE layer increase due to the melting of thin lamellae and the stability of connecting bridge structure during *** corresponding air permeability,po rosity,wetta bility of liquid electrolyte and mechanical property of the heat-set microporous membrane increase,exhibiting better electrochemical ***,when the heat-setting temperature is further increased to 140℃,higher than the melting point of PE resin,some pores are closed since the lamellae and connecting bridges melt and shrink during heat-setting,resulting in a decrease of air permeability and *** contrast,there is negligible change in the PP layer within the above heat-setting temperature *** study successfully builds the relationship between the stable pore structure and property of microporous membrane during heat-setting,which is helpful to guide the production of high-pe rformance PP/PE/PP lithium batteries separator.

关键词： PP/HDPE bilayer microporous membranes Heat-setting temperature SAXS

Combining TDLAS and multi-fusion algorithms for methane gas concentration detection

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Optoelectronics Letters 2024年第6期20卷 353-359页

作者： shi Guojun song Xinmin DONG Taiji School of Information&Electrical Engineering Heilongjiang Bayi Agricultural UniversityDaqing 163319China College of Electrical and Information Engineering Northeast Petroleum UniversityDaqing 163318China

High-precision methane gas detection is of great importance in industrial safety, energy production and environmental protection, etc. However, in the existing measurement techniques, the methane gas concentration information is susceptible to noise, which leads to its useful signal being drowned by noise. A fusion algorithm of variational modal decomposition(VMD) and improved wavelet threshold filtering is proposed, which is used in combination with tunable diode laser absorption spectroscopy(TDLAS) to implement a non-contact, high-resolution methane gas concentration detection. The fusion algorithm can perform noise reduction and further segmentation of the methane gas detection signal. And the simulation and experiment verify the effectiveness of the fusion algorithm, and the experimental results show that for the detection of air containing 10 ppm, 30 ppm, 60 ppm, 80 ppm, and 99 ppm methane, the errors are 12.75%, 8.18%, 3.37%, 2.46%, and 1.78%, respectively.

关键词： Combining TDLAS and multi-fusion algorithms for methane gas concentration detection TDLAS

AWeb Application Fingerprint Recognition Method Based on Machine Learning

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 887-906页

作者： Yanmei shi Wei Yu Yanxia Zhao Yungang jia School of Integrated Circuit Science and Engineering Tianjin University of TechnologyTianjin300382China College of International Business Zhejiang Yuexiu UniversityShaoxing312030China School of Public Administration Zhejiang Gongshang UniversityHangzhou310018China Tianjin Branch of National Computer Network Emergency Response Technical Team/Coordination Center of China Tianjin300100China

Web application fingerprint recognition is an effective security technology designed to identify and classify web applications,thereby enhancing the detection of potential threats and *** fingerprint recognition methods,which rely on preannotated feature matching,face inherent limitations due to the ever-evolving nature and diverse landscape of web *** response to these challenges,this work proposes an innovative web application fingerprint recognition method founded on clustering *** method involves extensive data collection from the Tranco List,employing adjusted feature selection built upon Wappalyzer and noise reduction through truncated SVD dimensionality *** core of the methodology lies in the application of the unsupervised OPTICS clustering algorithm,eliminating the need for preannotated *** transforming web applications into feature vectors and leveraging clustering algorithms,our approach accurately categorizes diverse web applications,providing comprehensive and precise fingerprint *** experimental results,which are obtained on a dataset featuring various web application types,affirm the efficacy of the method,demonstrating its ability to achieve high accuracy and broad *** novel approach not only distinguishes between different web application types effectively but also demonstrates superiority in terms of classification accuracy and coverage,offering a robust solution to the challenges of web application fingerprint recognition.

关键词： Web application fingerprint recognition unsupervised learning clustering algorithm feature extraction automated testing network security