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Microstructure and properties of LZQT600-3 HCCDIBs for plunger pump cylinder

China Foundry 2024年第2期21卷 197-204页

作者： Chun-jie Xu Yuan-ying Jin Dong Ma Zhen Zhao Jia-wei Qi Shang Sui Xiang-quan Wu Can Guo Zhong-ming Zhang Yong-hui Liu Dan Shechtman School of Materials Science and Engineering Xi'an University of TechnologyXi'an 710048China Xi'an Shechtman Nobel Prize New Materials Institute Xi'an 710048China Tongchuan Huazhu Precision Technology Co. Ltd.Tongchuan 727100ShaanxiChina Faculty of Materials Science and Engineering Technion-Israel Insititue of TechnologyHaifa 3200003Israel

It is important to improve the comprehensive performance of the ductile iron bars(DIBs)for the cylinder block of the extra high pressure hydraulic plunger pump and accelerate the industrial *** this work,the LZQT600-3 DIBs with the diameter of 145 mm were prepared by the horizontal continuous casting(HCC)process,that is,LZQT600-3 *** microstructure and room temperature tensile properties of different sections[left-edge(surface layer),left-1/2R(left half of the radius),and the center of the HCCDIBs]were *** results show that the spheroidization of LZQT600-3 HCCDIBs matrix from the left-edge,left-1/2R to the center is at nodulizing grade II and *** the cooling rate gradually decreases from surface to the center of the HCCIBs,the number of spheroidized graphite is gradually reduced,the size is gradually increased,the shape factor is decreased,and the pearlite content and lamellate spacing are *** the horizontal direction of the section,the hardness of the material is distributed symmetrically around the center of the *** the vertical direction,the hardness distribution in the center of the HCCDIBs is asymmetrical due to the gravity during the solidification ***,the microstructure in the lower part of the section solidifies relatively *** left-edge has the best tensile mechanical properties,and the ultimate tensile strength,yield tensile strength and elongation are 597.3 MPa,418.5 MPa and 9.6%,*** tensile fracture belongs to the ductile-brittle hybrid *** comprehensive performances of LZQT600-3 HCCDIBs meet the actual application requirements of ultra-high pressure hydraulic plunger pump cylinder.

关键词： horizontal continuous casting(HCC) nodular cast iron ductile iron bars microstructure mechanical properties

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Better use of experience from other reservoirs for accurate production forecasting by learn-to-learn method

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Petroleum Science 2024年第1期21卷 716-728页

作者： Hao-Chen Wang Kai Zhang Nancy Chen Wen-Sheng Zhou Chen Liu Ji-Fu Wang Li-Ming Zhang Zhi-Gang Yu Shi-Ti Cui Mei-Chun Yang China University of Petroleum(East China) 66 Changjiang West RoadQingdao West Coast New AreaQingdao266580ShandongChina University of Calgary 2500 University Dr NWCalgaryT2N 1N4AlbertaCanada Qingdao University of Technology Qingdao266071ShandongChina State Key Laboratory of Offshore Oil Exploitation Beijing100028China CNOOC Research Institute Ltd. Beijing100028China CNPC Tarim Oilfield Branch Company Korla841000XinjiangChina National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields Xi'an710000ShaanxiChina Sinopec Matrix Co. LTDQingdao266000ShandongChina

To assess whether a development strategy will be profitable enough,production forecasting is a crucial and difficult step in the *** development history of other reservoirs in the same class tends to be studied to make predictions ***,the permeability field,well patterns,and development regime must all be similar for two reservoirs to be considered in the same *** results in very few available experiences from other reservoirs even though there is a lot of historical information on numerous reservoirs because it is difficult to find such similar *** paper proposes a learn-to-learn method,which can better utilize a vast amount of historical data from various ***,the proposed method first learns how to learn samples before directly learning rules in ***,by utilizing gradients from networks with independent parameters and copied structure in each class of reservoirs,the proposed network obtains the optimal shared initial parameters which are regarded as transferable information across different *** on that,the network is able to predict future production indices for the target reservoir by only training with very limited samples collected from reservoirs in the same *** cases further demonstrate its superiority in accuracy to other widely-used network methods.

关键词： Production forecasting Multiple patterns Few-shot learning Transfer learning

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Capturing and visualizing the phase transition mediated thermal stress of thermal barrier coating materials via a cross-scale integrated computational approach

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Journal of Advanced Ceramics 2024年第4期13卷 413-428页

作者： Mengdi Gan Tianlong Lu Wei Yu Jing Feng Xiaoyu Chong Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The generation and evaluation of severely high thermal stress(σ)is known to be responsible for failure of thermal barrier coatings(TBCs)during thermal *** is crucial and challenging to capture fluctuations inσcaused by the phase transition,which has motivated us to develop a high-throughput multiscale evaluation method forσin TBCs that considers the phase transition of the top ceramic materials by coupling first-principles calculations with finite element *** method quantitatively evaluates and visualizesσof the real TBC structure under thermal cycling by multifield ***,the thermophysical properties calculated by the first-principles calculations consider the effects of temperature and phase transition,which not only reduces the cost of obtaining data but also has a more physical *** this work,rare earth tantalites(RETaO_(4))are introduced as ceramic layers,and the results demonstrate thatσundergoes a rapid escalation near the phase transition temperature(T_(t)),particularly in the TBCs_GdTaO_(4) system,where it rises from 224 to 435 *** discontinuity inσmay originate from the significant alterations in Young’s modulus(increase by 27%–78%)and thermal conductivity(increase by 53%–146%)near T_(t).The TBCs_NdTaO_(4) and TBCs_SmTaO_(4) systems exhibit noteworthy temperature drop gradients and minimalσfluctuations,which are beneficial for extending service lifetime of *** approach facilitates the prediction of failure mechanisms and provides theoretical guidance for the reverse design of TBC materials to obtain low thermal stress systems.

关键词： thermal conductivity first-principles calculations thermodynamics thermal stress thermophysical properties

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Multi-surrogate framework with an adaptive selection mechanism for production optimization

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Petroleum Science 2024年第1期21卷 366-383页

作者： Jia-Lin Wang Li-Ming Zhang Kai Zhang Jian Wang Jian-Ping Zhou Wen-Feng Peng Fa-Liang Yin Chao Zhong Xia Yan Pi-Yang Liu Hua-Qing Zhang Yong-Fei Yang Hai Sun School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Qingdao University of Technology Qingdao266580ShandongChina College of Science China University of PetroleumQingdao266580ShandongChina Zepu Oil and Gas Development Department PetroChina Tarim Oilfield CompanyKorla841000XinjiangChina Hainan Branch of CNOOC Ltd Haikou70311HainanChina

Data-driven surrogate models that assist with efficient evolutionary algorithms to find the optimal development scheme have been widely used to solve reservoir production optimization ***,existing research suggests that the effectiveness of a surrogate model can vary depending on the complexity of the design problem.A surrogate model that has demonstrated success in one scenario may not perform as well in *** the absence of prior knowledge,finding a promising surrogate model that performs well for an unknown reservoir is ***,the optimization process often relies on a single evolutionary algorithm,which can yield varying results across different *** address these limitations,this paper introduces a novel approach called the multi-surrogate framework with an adaptive selection mechanism(MSFASM)to tackle production optimization *** consists of two *** the first stage,a reduced-dimensional broad learning system(BLS)is used to adaptively select the evolutionary algorithm with the best performance during the current optimization *** the second stage,the multi-objective algorithm,non-dominated sorting genetic algorithm II(NSGA-II),is used as an optimizer to find a set of Pareto solutions with good performance on multiple surrogate models.A novel optimal point criterion is utilized in this stage to select the Pareto solutions,thereby obtaining the desired development schemes without increasing the computational load of the numerical *** two stages are combined using sequential transfer *** the two most important perspectives of an evolutionary algorithm and a surrogate model,the proposed method improves adaptability to optimization problems of various reservoir *** verify the effectiveness of the proposed method,four 100-dimensional benchmark functions and two reservoir models are tested,and the results are compared with those obtained by six other surrogate-model-based *** res

关键词： Production optimization Multi-surrogate models Multi-evolutionary algorithms Dimension reduction Broad learning system

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Study on Image Recognition Algorithm for Residual Snow and Ice on Photovoltaic Modules

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Energy Engineering 2024年第4期121卷 895-911页

作者： Yongcan Zhu JiawenWang Ye Zhang Long Zhao Botao Jiang Xinbo Huang College of Electronics and Information Xi’an Polytechnic UniversityXi’an710048China Xi’an Key Laboratory of Interconnected Sensing and Intelligent Diagnosis for Electrical Equipment Xi’an710048China

The accumulation of snow and ice on PV modules can have a detrimental impact on power generation,leading to reduced efficiency for prolonged ***,it becomes imperative to develop an intelligent system capable of accurately assessing the extent of snow and ice coverage on PV *** address this issue,the article proposes an innovative ice and snow recognition algorithm that effectively segments the ice and snow areas within the collected ***,the algorithm incorporates an analysis of the morphological characteristics of ice and snow coverage on PV modules,allowing for the establishment of a residual ice and snow recognition *** process utilizes both the external ellipse method and the pixel statistical method to refine the identification *** effectiveness of the proposed algorithm is validated through extensive testing with isolated and continuous snow area *** results demonstrate the algorithm’s accuracy and reliability in identifying and quantifying residual snow and ice on PV *** conclusion,this research presents a valuable method for accurately detecting and quantifying snow and ice coverage on PV *** breakthrough is of utmost significance for PV power plants,as it enables predictions of power generation efficiency and facilitates efficient PV maintenance during the challenging winter conditions characterized by snow and *** proactively managing snow and ice coverage,PV power plants can optimize energy production and minimize downtime,ensuring a sustainable and reliable renewable energy supply.

关键词： Photovoltaic(PV)module residual snow and ice snow detection feature extraction image processing

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Sliding behaviors of the trapezoidal roof rock block under a lateral dynamic disturbance

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 741-760页

作者： Feng Dai Wancheng Zhu Min Ren Shunchuan Wu Leilei Niu Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming650093China Center for Rock Instability and Seismicity Research Department of Mining EngineeringSchool of Resource and Civil EngineeringNortheastern UniversityShenyang110819China

The surrounding rock of underground space is always affected by external dynamic disturbance from the side position,such as blasting vibration from a stope at the same level or seismic waves from adjacent strata.A series of laboratory tests,numerical simulations and theoretical analyses were carried out in this study to disclose the sliding mechanism of roof rock blocks under lateral ***,the experiments on trapezoidal key block under various clamping loads and disturbance were conducted,followed by numerical simulations using the fast Lagrangian analysis of continua(FLAC3D).Then,based on the conventional wave propagation model and the classical shear-slip constitutive model,a theoretical model was proposed to capture the relative displacement between blocks and the sliding displacement of the key *** results indicate that the sliding displacement of the key block increased linearly with the disturbance energy and decreased exponentially with the clamping load when the key block was disturbed to slide(without instability).Meanwhile,when the key block was disturbed to fall,two types of instability process may appear as immediate type or delayed *** addition,the propagation of stress waves in the block system exhibited obvious low-velocity and lowfrequency characteristics,resulting in the friction reduction effect appearing at the contact interface,which is the essential reason for the sliding of rock *** results can be applied to practical underground engineering and provide valuable guidance for the early detection and prevention of rockfalling disasters.

关键词： Lateral dynamic disturbance Trapezoidal rock block system Low-velocity and low-frequency wave Friction reduction effect Instability mode

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Spectral Fittings of Warm Coronal Radiation with High Seed Photon Temperature: Apparent Low-temperature and Flat Soft Excess in AGNs

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Research in Astronomy and Astrophysics 2024年第7期24卷 138-147页

作者： Ze-Yuan Tang Jun-Jie Feng Jun-Hui Fan School of Mathematics and Information Science Guangzhou University Center for Astrophysics Guangzhou University Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Key Laboratory for Astronomical Observation and Technology of Guangzhou

A warm corona has been widely proposed to explain the soft excess （SE） in X-ray above the 2–10 ke V power law extrapolation in Active Galactic Nuclei （AGNs）.In actual spectral fittings,the warm coronal seed photon temperature（Ts） is usually assumed to be far away from the soft X-ray,but kTscan reach close to 0.1 ke V in the standard accretion disk *** this study,we used Monte Carlo simulations to obtain radiation spectra from a slab-like warm corona and fitted the spectra using the spherical-geometry-based routine THCOMP or a thermal *** findings reveal tha high Tscan influence the fitting results.A moderately high kTs（around 0.03 ke V） can result in an apparent low-temperature and flat SE,while an extremely high kTs（around 0.07 ke V） can even produce an unobserved blackbody-like *** conclusions indicate that,for spectral fittings of the warm coronal radiation （SE in AGNs）,kTsshould be treated as a free parameter with an upper limit,and an accurate coronal geometry is necessary when kTs>0.01 ke V.

关键词： accretion accretion disks black hole physics galaxies: active

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Effects of extracellular vesicle-derived noncoding RNAs on pre-metastatic niche and tumor progression

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Genes & Diseases 2024年第1期11卷 176-188页

作者： Zhuang Chen Qiming Wang Jinbo Liu Wenkang Wang Weitang Yuan Yang Liu Zhenqiang Sun Chengzeng Wang Department of Colorectal Surgery The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan 450052China Academy of Medical Sciences of Zhengzhou University ZhengzhouHenan 450001China Department of Internal Medicine Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenan 450008China Department of Breast Surgery The First Affliated Hospital of Zhengzhou UniversityZhengzhouHenan 450052China Department of Radiotherapy Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenan 450008China The First Affiliated Hospital of Zhengzhou University ZhengzhouHenan 450052China

A pre-metastatic niche(PMN)is a protective microenvironment that facilitates the colonization of disseminating tumor cells in future metastatic *** vesicles(EVs)play a role in intercellular communication by delivering cargoes,such as noncoding RNAs(ncRNAs).The pivotal role of extracellular vesicle-derived noncoding RNAs(EV-ncRNAs)in the PMN has attracted increasing *** this review,we summarized the effects of EV-ncRNAs on the PMN in terms of immunosuppression,vascular permeability and angiogenesis,inflammation,metabolic reprogramming,and fibroblast *** particular,we provided a comprehensive overview of the effects of EV-ncRNAs on the PMN in different ***,we discussed the promising clinical applications of EV-ncRNAs,including their potential as diagnostic and prognostic markers and therapeutic targets.

关键词： Biomarker Extracellular vesicles Noncoding RNAs

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Highly Thermally Conductive Polydimethylsiloxane Composites with Controllable 3D GO@f-CNTs Networks via Self-sacrificing Template Method

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Chinese Journal of Polymer Science 2024年第7期42卷 897-906,I0005页

作者： Shuang-Shuang Wang Dian-Ying Feng Zhi-Ming Zhang Xia Liu Kun-Peng Ruan Yong-Qiang Guo Jun-Wei Gu Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an710072China Shandong Institute of Nonmetallic Materials Jinan250031China Queen Mary University of London Engineering School Northwestern Polytechnical UniversityXi’an710072China

Constructing controllable thermal conduction networks is the key to efficiently improve thermal conductivities of polymer *** this work,graphite oxide(GO)and functionalized carbon nanotubes(f-CNTs)are combined to prepare“Line-Plane”-like hetero-structured thermally conductive GO@f-CNTs fillers,which are then performed to construct controllable 3D GO@f-CNTs thermal conduction networks via selfsacrificing template method based on oxalic ***,thermally conductive GO@f-CNTs/polydimethylsiloxane(PDMS)composites are fabricated via casting *** the size of oxalic acid is 0.24 mm and the volume fraction of GO@f-CNTs is 60 vol%,GO@f-CNTs/PDMS composites present the optimal thermal conductivity coefficient(λ,4.00 W·m^(-1)·K^(-1)),about 20 times that of theλof neat PDMS(0.20 W·m^(-1)·K^(-1)),also much higher than theλ(2.44 W·m^(-1)·K^(-1))of GO/f-CNTs/PDMS composites with the same amount of randomly dispersed ***,the obtained GO@f-CNTs/PDMS composites have excellent thermal stability,whoseλdeviation is only about 3%after 500 thermal cycles(20-200℃).

关键词： Polydimethylsiloxane Hetero-structured thermally conductive fillers Self-sacrificing template Thermal conduction networks

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Probing the Gamma-Ray Emission Region of Five TeV Flat Spectrum Radio Quasars

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Research in Astronomy and Astrophysics 2024年第6期24卷 156-169页

作者： Hu-Bing Xiao Hai-Tao Cao Rui Xue Jin-Ting Cai Ge-Ge Wang Marina Manganaro Shao-Hua Zhang Zhi-Hao Ouyang Li-Ping Fu Jun-Hui Fan Shanghai Key Lab for Astrophysics Shanghai Normal UniversityShanghai 200234China School of Information Engineering Guangzhou Panyu PolytechnicGuangzhou 511483China Department of Physics Zhejiang Normal UniversityJinhua 321004China College of Mathematics and Physics Guangxi Minzu UniversityNanning 530006China Key Laboratory of Cosmology and Astrophysics(Liaoning) College of SciencesNortheastern UniversityShenyang 110819China Department of Physics University of RijekaRijeka 51000Croatia Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Key Laboratory for Astronomical Observation and Technology of Guangzhou Guangzhou 510006China Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Guangzhou 510006China

The location ofγ-ray emission of blazars remains a contested topic,inspiring the development of numerous investigative techniques to address this *** this work,we analyzed Fermiγ-ray light curves in the GeV and MeV bands,employing the discrete cross-correlation function method to discern time lags between the two *** 4C+21.35,Ton 599,B21420+32,and PKS 1510-089,we identified a time lag spanning several days,while for PKS 1441+25,the time lag was not statistically *** results imply that the soft photons necessary for inverse Compton scattering predominantly originate from the dusty torus in the first four sources,whereas for PKS1441+25,they seem to be sourced mainly from the broad-line *** analysis of the opacity(τγγ)and the GeV spectra study supports the conclusion that the location of the dissipation region must be beyond the BLR to avoid significant ***,for PKS 1441+25,the emission region is also posited to lie outside yet proximate to the *** parameters of describing the emission region were obtained by fitting broadband spectral energy distribution with contemporaneous observation *** findings suggest that for the five TeV FSRQs,during Te V flaring events,the jet appears to maintain an equilibrium between the energy density of the magnetic field and that of the particles for all investigated sources,with the exceptions of 4C+21.35 and PKS1441+*** terms of the overall jet power,particle energy is the dominant contributor,and the observed blazar radiation cannot be solely attributed to the magnetic field,except in the case of 4C+***,magnetic reconnection is unlikely to be the primary mechanism behind particle acceleration in these systems.

关键词： galaxies:active gamma-rays:galaxies galaxies:jets

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