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Mechanical Modeling and Analysis of Stability Deterioration of Production Well During Marine Hydrate Depressurization Production

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China Ocean Engineering 2024年第2期38卷 338-351页

作者： sun Huan-zhao CHANG Yuan-jiang sun Bao-jiang WANG Kang CHEN Guo-ming LI Hao DAI yong-guo Centre for Offshore Engineering and Safety Technology China University of Petroleum(East China)Qingdao 266580China School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580China Jiangsu Shuguang Oil Tools Co. LtdTaizhou 225532China

Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate ***,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production ***,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks consideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate decomposition during *** fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well considering the effects of hydrate *** on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field coupling model of the force state of the production well considering the effect of hydrate decomposition and formation subsidence is established,and a solver is *** analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the decomposition of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability *** higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even *** work can provide a theoretical reference for the stability maintaining of the production well.

关键词： natural gas hydrate production well depressurization production formation deformation stability deterioration

Effect of annealing temperature on magnetic properties of a sintered Nd-Fe-B magnet after grain boundary diffusion with Dy_(70)Cu_(30) alloy

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Journal of Rare Earths 2024年第1期42卷 116-120,I0004页

作者： Ruipeng Qian Yuxuan Ma Fugang Chen Hui sun yong Zhao Yunlong Chen School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212003China School of Energy and Power Engineering Jiangsu University of Science and TechnologyZhenjiang212003China

Grain boundary diffusion process(GBDP)has been developed as an effective approach to increase the coercivity of sintered Nd-Fe-B magnets by regulating the compositions and phase distributions near grain *** work aims to explore how to select the optimum annealing temperature after *** this work GBDP was performed on a sintered Nd-Fe-B magnet using Dy_(70)Cu_(30) *** GBDP the low eutectic temperature of the grain boundary phases decreases from the initial 492 to 451℃.The magnetic property dependent on different annealing temperatures near the low eutectic temperature was *** magnetic properties,especially the squareness factor of demagnetization curve show a strong dependence on the annealing *** GBDP the optimal magnetic properties can be obtained after annealing just above the low eutectic temperature of the grain boundary *** mechanism is discussed based on the microstructure analysis.

关键词： Nd-Fe-B magnet Grain boundary diffusion Annealing Dy_(70)Cu_(30)alloy Rare earths

N-glycosylation of Wnt3 regulates the progression of hepatocellular carcinoma by affecting Wnt/β-catenin signal pathway

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2769-2780页

作者： Xin-Zhan Zhang Xiao-Chuan Mo Zhu-Ting Wang Rong sun Da-quan sun Department of Biochemistry and Molecular Biology&Research Center for Basic Medical Sciences Guizhou Medical UniversityGuiyang 550025Guizhou ProvinceChina

BACKGROUND Wnt/FZD-mediated signaling pathways are activated in more than 90%of hepatocellular carcinoma(HCC)cell *** a well-known secretory glycoprotein,Wnt3 can interact with FZD receptors on the cell surface,thereby activating the Wnt/β-catenin signaling ***,the N-glycosylation modification site of Wnt3 and the effect of this modification on the biological function of the protein are still *** To investigate the effect of Wnt3 N-glycosylation on the biological function of HCC *** Site-directed mutagenesis was used to verify the Wnt3 N-glycosylation sites,actinomycin D treatment was used to detect the stability of Wnt3 after site-directed mutation,the binding of the N-glycosylation site-directed mutant Wnt3 to FZD7 was observed by laser confocal microscopy,and the effects of the N-glycosylation site-directed mutation of Wnt3 on the Wnt/β-catenin signaling pathway and the progression of HCC cells were detected by western blot and cell function *** Wnt3 has two N-glycosylation-modified sites(Asn90 and Asn301);when a single site at amino acid 301 is mutated,the stability of Wnt3 is weakened;the binding ability of Wnt3 to FZD7 decreases when both sites are mutated simultaneously;and the level of proteins related to the Wnt/β-catenin signaling pathway is *** proliferation,migration and invasion are also weakened in the case of single 301 site and double-site *** These results indicate that by inhibiting the N-glycosylation of Wnt3,the proliferation,migration,invasion and colony formation abilities of liver cancer cells can be weakened,which might provide new therapeutic strategies for clinical liver cancer in the future.

关键词： Wnt3 N-glycosylation Hepatocellular carcinoma Liver cancer Wnt/β-catenin FZD7

Special Unipotent Representations of Simple Linear Lie Groups of Type A

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Acta Mathematica Sinica,English Series 2024年第3期40卷 707-716页

作者： Dan BARBASCH Jia Jun MA Bin yong sun Chen Bo ZHU Department of Mathematics Cornell UniversityIthacaNY 14853USA School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China Department of Mathematics Xiamen University Malaysia CampusSepangSelangor Darul Ehsan43900Malaysia Institute for Advanced Study in Mathematics&New Cornerstone Science Laboratory Zhejiang UniversityHangzhou 310058P.R.China Department of Mathematics National University of Singapore10 Lower Kent Ridge RoadSingapore 119076

Let G be a special linear group over the real,the complex or the quaternion,or a special unitary *** this note,we determine all special unipotent representations of G in the sense of Arthur and Barbasch-Vogan,and show... 详细信息

关键词： Special unipotent representations unitary representations coherent continuation Weyl group representations

Study on synergistic leaching of potassium and phosphorus from potassium feldspar and solid waste phosphogypsum via coupling reactions

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Chinese Journal of Chemical Engineering 2024年第1期65卷 117-129页

作者： Chao Li Shizhao Wang Yunshan Wang Xuebin An Gang Yang yong sun School of Chemical Engineering and Technology Hebei University of TechnologyTianjin 300130China National Engineering Research Center of Green Recycling for Strategic Metal Resources Chinese Academy of SciencesBeijing 100190China School of Engineering Edith Cowan University270 Joondalup DriveJoondalupWA 6027Australia Key Laboratory of Carbonaceous Wastes Processing and Process Intensification of Zhejiang Province The University of Nottingham Ningbo ChinaNingbo 315100China

To achieve the resource utilization of solid waste phosphogypsum(PG)and tackle the problem of utilizing potassium feldspar(PF),a coupled synergistic process between PG and PF is proposed in this *** study investigates the features of P and F in PG,and explores the decomposition of PF using hydrofluoric acid(HF)in the sulfuric acid system for K leaching and leaching of P and F in *** impact factors such as sulfuric acid concentration,reaction temperature,reaction time,material ratio(PG/PF),liquid–solid ratio,PF particle size,and PF calcination temperature on the leaching of P and K is systematically investigated in this *** results show that under optimal conditions,the leaching rate of K and P reach more than 93%and 96%,*** study using shrinking core model(SCM)indicates two significant stages with internal diffusion predominantly controlling the leaching of *** apparent activation energies of these two stages are 11.92 kJ·mol^(-1)and 11.55 kJ·mol^(-1),respectively.

关键词： Phosphogypsum Potassium feldspar Coupling reaction Leaching Waste treatment Kinetics

Semiparametric Additive Hazards Model with Doubly Truncated Data

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Acta Mathematica Sinica,English Series 2024年

作者： Yi Jin ZHANG Liu quan sun Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences University of Chinese Academy of Sciences

Doubly truncated data arise when the survival times of interest are observed only if they fall within certain random intervals. In this paper, we consider a semiparametric additive hazards model with doubly truncated data, and propose a weighted estimating equation approach to estimate the regression coefficients, where the weights are estimated both parametrically and *** asymptotic properties of the resulting estimators are established. Simulation studies demonstrate that the proposed estimators perform well in a finite sample. An application to Parkinson’s disease data is provided.

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Design study of charge-stripping scheme of heavy ion beams for HIAF-BRing

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Nuclear Science and Techniques 2024年第5期35卷 30-41页

作者： Jun-Jie Zhang Zhi-You Xu Jin-quan Zhang Wen-Wen Ge Liang-Ting sun Huan-Yu Zhao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Charge strippers play an essential role in heavy-ion accelerators by stripping the projectile ions to higher charge states to enhance the acceleration efficiency downstream of the *** the high-energy mode of the booster ring(BRing)of the high-intensity heavy-ion accelerator facility,the pre-accelerated ions from the iLinac will be stripped by a carbon foil to higher charge states and then injected into the *** key parameters of the stripper and stripped ions were calculated,and the influence of stripping on the beam quality was *** get high stripping efficiencies,the foil thicknesses and resultant charge state distributions for the typical ions were determined by the code *** equilibrium thickness was obtained for the U beam,while the stripper thicknesses for the Xe and Kr beams were determined based on a compromise between the stripped charge states and the stripping *** energy loss,energy straggling,and emittance growth due to stripping have a non-negligible impact on the transport of the stripped beams and the injection of the ***,these parameters were simulated by *** addition,the foil’s temperature evolution,which greatly affects the foil lifetime,was simulated by *** maximum temperature of the foil bombarded by the U and Xe beams with the nominal parameters will exceed the safe value in terms of the impact of evaporation on the foil’s *** the foil temperature constraint,the highest tolerable beam intensity and the injected ion number into the ring were derived for different beam *** results of this paper will present important reference data for the optimization design and commissioning of the beamline and injection to the BRing for the stripped ions.

关键词： High-intensity heavy-ion accelerator facility Charge stripper Energy spread Thermal analysis Emittance growth Injection turns

Nomogram model including LATS2 expression was constructed to predict the prognosis of advanced gastric cancer after surgery

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 518-528页

作者： Nan sun Bi-Bo Tan yong Li Department of Blood Transfusion The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hubei ProvinceChina Third Department of General Surgery the Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina

BACKGROUND Gastric cancer is a leading cause of cancer-related deaths *** assessments are typically based on the tumor-node-metastasis(TNM)staging system,which does not account for the molecular heterogeneity of this ***2,a tumor suppressor gene involved in the Hippo signaling pathway,has been identified as a potential prognostic biomarker in gastric *** To construct and validate a nomogram model that includes LATS2 expression to predict the survival prognosis of advanced gastric cancer patients following ra-dical surgery,and compare its predictive performance with traditional TNM *** A retrospective analysis of 245 advanced gastric cancer patients from the Fourth Hospital of Hebei Medical University was *** patients were divided into a training group(171 patients)and a validation group(74 patients)to deve-lop and test our prognostic *** performance of the model was determined using C-indices,receiver operating characteristic curves,calibration plots,and decision *** The model demonstrated a high predictive accuracy with C-indices of 0.829 in the training set and 0.862 in the validation *** under the curve values for three-year and five-year survival prediction were significantly robust,suggesting an excellent discrimination *** plots confirmed the high concordance between the predictions and actual survival *** We developed a nomogram model incorporating LATS2 expression,which significantly outperformed conven-tional TNM staging in predicting the prognosis of advanced gastric cancer patients *** model may serve as a valuable tool for individualized patient management,allowing for more accurate stratification and im-proved clinical *** validation in larger patient cohorts will be necessary to establish its generaliza-bility and clinical utility.

关键词： Gastric cancer LATS2 Column line graph Prognosis Advanced gastric cancer survival Molecular biomarkers Predictive analytics in oncology Survival analysis

Interfacial friction effects on sealing performances of elastomer packer

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Petroleum Science 2024年第3期21卷 2037-2047页

作者： Peng-Cheng Wang Ming-Hui Chen Jim Jenkinson yong-Xin Song Li sun Department of Mechanical Engineering University of HoustonHoustonTX77024USA Guren Nanomaterials Suzhou215127JiangsuChina Department of Marine Engineering Dalian Maritime UniversityDalian116026LiaoningChina

Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic *** practice sealing performances of such plugs are normally evaluated through pressure tests,and in numerical simulation studies,maximum contact stress,average contact stress and contact length data are used to determine sealing quality between a packer and *** previous studies,the impact of friction forces on sealing performance is often *** work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing *** first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac *** we compared analytical calculation results with Finite Element Analysis simulation using a simplified tubular geometry and showed the significant influences on interfacial friction on elastomer packer stress distribution,deformation,and contact stress after *** the demonstration of validity of FEA method,we conducted systematic numerical simulation studies to show how the interfacial friction coefficients can affect the maximum contact stress,average contact stress,contact stress distribution,and maximum mises stress for an actual packer used in plug *** addition,we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial *** study underscores the critical role that friction forces play in Frac plug performance and provides a new dimension for optimizing packer design by controlling interfacial interactions at the packer contact surfaces.

关键词： Elastomer seal Friction Sealing performance Contact stress