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Wellbore-heat-transfer-model-based optimization and control for cooling downhole drilling fluid

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Petroleum Science 2024年第3期21卷 1955-1968页

作者： Chao Wang He Liu Guo-Wei yu Chen yu xian-Ming Liu peng Huang Yangtze University State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) CNPC Bohai Drilling Engineering Co. Ltd Exploration Development and Construction Engineering Division of PetroChina Jidong Oilfield Company Henan University of Urban Construction

To address the two critical issues of evaluating the necessity of implementing cooling techniques and achieving real-time temperature control of drilling fluids underground in the current drilling fluid cooling technology, we first established a temperature and pressure coupled downhole heat transfer model, which can be used in both water-based and oil-based drilling fluid. Then, fourteen factors, which could affect wellbore temperature, were analyzed. Based on the standard deviation of the downhole temperature corresponding to each influencing factor, the influence of each factor was quantified. The influencing factors that can be used to guide the drilling fluid's cooling technology were drilling fluid thermal conductivity, drilling fluid heat capacity, drilling fluid density, drill strings rotation speed, pump rate, viscosity, ROP, and injection temperature. The nondominated sorting genetic algorithm was used to optimize these six parameters, but the optimization process took 182 min. Combining these eight parameters' influence rules with the nondominated sorting genetic algorithm can reduce the optimization time to 108 s. Theoretically, the downhole temperature has been demonstrated to increase with the inlet temperature increasing linearly under quasi-steady states. Combining this law and PID, the downhole temperature can be controlled, which can reduce the energy for cooling the surface drilling fluid and can ensure the downhole temperature reaches the set value as soon as possible.

关键词： Drilling Cooling Influencing factors Analysis Optimization Control

Twelve-year outcomes after revascularization for ostial/shaft lesions in unprotected left main coronary artery

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Journal of Geriatric Cardiology 2020年第6期17卷 338-343页

作者： xian-peng yu yu LI Ji-Qiang HE Ze-Ning JIN Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijingChina Department of Cardiology and Macrovascular Disease Beijing Tiantan HospitalCapital Medical UniversityBeijingChina

Objective To evaluate a very long-term clinical outcomes of patients treated with coronary artery bypass grafting(CABG) and percutaneous coronary intervention(PCI) with drug-eluting stents(DES) for ostial/shaft lesions in unprotected left main coronary artery(ULMCA). Methods & Results A total of 472 patients with isolated ostial/shaft lesions in ULMCA were enrolled, who received DES implantation or underwent CABG between January 2003 and July 2009 in Beijing Anzhen Hospital. The major endpoints of this study were death, repeat revascularization, non-procedural myocardial infarction(MI) and stroke. The median follow-up was twelve years(interquartile range: 9.4–14.0 years) in the overall patients. There were no significant differences of incidence of death(23.3% vs. 25.6%, P = 0.227), repeat revascularization(27.3% vs. 28.4%, P = 0.423), non-procedural MI(20.0% vs. 14.5%, P = 0.561), and stroke(6.1% vs. 9.3%, P = 0.255) between PCI and CABG groups before multivariate adjusting. After adjusting covariates with multivariate Cox hazard regression model, there were still no significant differences between PCI and CABG groups. Conclusions During the median follow-up of twelve years, we found that PCI with DES was as effective and safe as CABG in patients with left main ostial/shaft lesion in this observational study.

关键词： Coronary artery bypass grafting Left main ostial/shaft lesions Percutaneous coronary intervention Prognosis

Acute suppurative terminal cholangitis:Clinical characteristics of a new subtype of acute cholangitis

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Hepatobiliary & Pancreatic Diseases International 2024年第3期23卷 293-299页

作者： Rong-Tao Zhu Ye Li Chi-xian Zhang Wei-Jie Wang Ruo-peng Liang Jian Li Kai Bai yu-Ling Sun Department of Hepatobiliary and Pancreatic Surgery the First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China Zhengzhou Key Laboratory of Hepatobiliary and Pancreatic Diseases Zhengzhou 450052China Institute of Hepatobiliary and Pancreatic Diseases Zhengzhou UniversityZhengzhou 450052China Department of Pathology the First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China

Background:Acute suppurative terminal cholangitis(ASTC)is rarer than acute obstructive cholangitis and is not well *** explore this subtype of acute cholangitis,we described our clinical experience with ***:We performed a retrospective review of patients with ASTC admitted to our center from September 2014 to August *** analyzed their clinical characteristics,including etiology,clinical manifestations,imaging features,treatment and ***:A total of 32 ASTC patients were included in the *** majority of the patients had a history of biliary operations,and clinical manifestations were occult and *** positive rate of bacterial culture was 46.9%.All the patients had typical imaging features on computed tomography and magnetic resonance *** with effective antibiotics was provided as soon as diagnosis was *** treatment,most patients had a good *** levels of total bilirubin,aspartate aminotransferase,procalcitonin and gamma-glutamyltransferase were the characteristics of critically ill patients and were associated with relatively poor ***:Our results demonstrated that ASTC should be recognized as a new subtype of acute cholangitis,and that earlier diagnosis and more personalized treatments are needed.

关键词： Acute suppurative terminal cholangitis Acute cholangitis Gram-negative bacterial infections Diagnosis Treatment

Basic Survey Scheduling for the Wide Field Survey Telescope(WFST)

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Research in Astronomy and Astrophysics 2024年第1期24卷 59-69页

作者： Yan-peng Chen Ji-An Jiang Wen-Tao Luo xian-Zhong Zheng Min Fang Chao Yang yuan-yu Hong Zong-Fei Lü Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Department of Astronomy University of Science and Technology of ChinaHefei 230026China National Astronomical Observatory of Japan National Institutes of Natural Sciences2-21-1 OsawaMitakaTokyo 181-8588Japan Institute of Deep Space Sciences Deep Space Exploration LaboratoryHefei 230026China

Aiming at improving the survey efficiency of the Wide Field Survey Telescope, we have developed a basic scheduling strategy that takes into account the telescope characteristics, observing conditions, and weather conditions at the Lenghu site. The sky area is divided into rectangular regions, referred to as “tiles,” with a size of2°. 577 × 2°. 634 slightly smaller than the focal area of the mosaic CCDs. These tiles are continuously filled in annulars parallel to the equator. The brightness of the sky background, which varies with the moon phase and distance from the moon, plays a significant role in determining the accessible survey fields. Approximately 50connected tiles are grouped into one block for observation. To optimize the survey schedule, we perform simulations by taking into account the length of exposures, data readout, telescope slewing, and all relevant observing conditions. We utilize the Greedy Algorithm for scheduling optimization. Additionally, we propose a dedicated dithering pattern to cover the gaps between CCDs and the four corners of the mosaic CCD array, which are located outside of the 3° field of view. This dithering pattern helps to achieve relatively uniform exposure maps for the final survey outputs.

关键词： telescopes surveys Moon

Fourth-order phase-field modeling for brittle fracture in piezoelectric materials

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 837-856页

作者： yu TAN Fan peng Chang LIU Daiming peng xiangyu LI State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Science Chang'an UniversityXi'an 710064China Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Failure analyses of piezoelectric structures and devices are of engineering and scientific *** this paper,a fourth-order phase-field fracture model for piezoelectric solids is developed based on the Hamilton *** typical electric boundary conditions are involved in the present model to characterize the fracture behaviors in various physical situations.A staggered algorithm is used to simulate the crack *** polynomial splines over hierarchical T-meshes(PHT-splines)are adopted as the basis function,which owns the *** numerical simulations are performed to study the influence of the electric boundary conditions and the applied electric field on the fracture behaviors of piezoelectric *** electric boundary conditions may influence crack paths and fracture loads *** present research may be helpful for the reliability evaluation of the piezoelectric structure in the future applications.

关键词： isogeometric analysis(IGA) brittle fracture fourth-order phase-field model piezoelectric solid

Limit Theorems for Critical Galton-Watson Processes with Immigration Stopped at Zero

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Acta Mathematica Sinica,English Series 2024年第2期40卷 435-450页

作者： Dou Dou LI Mei ZHANG xian yu ZHANG College of Statistics and Data Science Faculty of ScienceBeijing University of TechnologyBeijing 100124P.R.China Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero *** precise estimation on the probability generating function of the n-th population are obtained,and the tail prob... 详细信息

关键词： Branching immigration critical life period limit theorems

LncRNA pol-lnc78 as a ceRNA regulates antibacterial responses via suppression of pol-miR-n199-3p-mediated SARM down-regulation in Paralichthys olivaceus

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Zoological Research 2024年第1期45卷 25-35页

作者： xian-Hui Ning Bing Han Ye peng Shao-Wu Yin College of Marine Science and Engineering Nanjing Normal UniversityNanjingJiangsu 210023China CAS Key Laboratory of Experimental Marine Biology Center for Ocean Mega-ScienceInstitute of OceanologyChinese Academy of SciencesQingdaoShandong 266071China Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province LianyungangJiangsu 222005China

Long non-coding RNAs(lncRNAs)function as key modulators in mammalian immunity,particularly due to their involvement in lncRNA-mediated competitive endogenous RNA(ceRNA)*** their recognized significance in mammals,research on lncRNAs in lower vertebrates remains *** the present study,we characterized the first immune-related lncRNA(pol-lnc78)in the teleost Japanese flounder(Paralichthys olivaceus).Results indicated that pol-lnc78 acted as a ceRNA for pol-miR-n199-3p to target the sterile alpha and armadillo motif-containing protein(SARM),the fifth discovered member of the Toll/interleukin 1(IL-1)receptor(TIR)adaptor *** ceRNA network regulated the antibacterial responses of flounder via the Toll-like receptor(TLR)signaling ***,SARM acted as a negative regulator and exacerbated bacterial infection by inhibiting the expression of inflammatory cytokines IL-1βand tumor necrosis factor-α(TNF-α).Pol-miR-n199-3p reduced SARM expression by specifically interacting with the 3’untranslated region(UTR),thereby promoting SARM-dependent inflammatory cytokine expression and protecting the host against bacterial ***,pol-lnc78 sponged pol-miR-n199-3p to ameliorate the inhibition of SARM *** infection,the negative regulators pol-lnc78 and SARM were significantly down-regulated,while pol-miR-n199-3p was significantly up-regulated,thus favoring host antibacterial *** findings provide novel insights into the mechanisms underlying fish immunity and open new horizons to better understand ceRNA crosstalk in lower vertebrates.

关键词： LncRNA SARM miRNA ceRNA Antibacterial response

Effects of cooling rate on microstructure and microhardness of directionally solidified Galvalume alloy

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China Foundry 2024年第3期21卷 213-220页

作者： Ji-peng Li De-gao Qiao Jian Li Xiao-yang Luo peng peng xian-tao Yan Xu-dong Zhang Gansu Jiu Steel Group Hongxing Iron and Steel Co. Ltd.Jiayuguan 735111GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000China

The influences of cooling rate on the phase constitution,microstructural length scale,and microhardness of directionally solidified Galvalume(Zn-55Al-1.6Si)alloy were investigated by directional solidification experiments at different withdrawal speeds(5,10,20,50,100,200,and 400μm·s^(-1)).The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites,Si-rich phase and(Zn-Al-Si)ternary eutectics at the withdrawal speed ranging from 5 to 400μm·s^(-1).As the withdrawal speed increases,the segregation of Si element intensifies,resulting in an increase in the area fraction of the Si-rich *** addition,the primary Al dendrites show significant refinement with an increase in the withdrawal *** relationship between the primary dendrite arm spacing(λ_(1))and the thermal parameters of solidification is obtained:λ_(1)=127.3V^(-0.31).Moreover,as the withdrawal speed increases from 5 to 400μm·s^(-1),the microhardness of the alloy increases from 90 HV to 151 *** is a combined effect of grain refinement and second-phase strengthening.

关键词： Galvalume alloy directional solidification microstructure length scale microhardness

Staging liver fibrosis with various diffusion-weighted magnetic resonance imaging models

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World Journal of Gastroenterology 2024年第9期30卷 1164-1176页

作者： Yan-Li Jiang Juan Li peng-Fei Zhang Feng-xian Fan Jie Zou Pin Yang peng-Fei Wang Shao-yu Wang Jing Zhang Department of Magnetic Resonance Imaging The Second Hospital&Clinical Medical SchoolLanzhou UniversityLanzhou 730030Gansu ProvinceChina Second Clinical School Lanzhou UniversityLanzhou 730030Gansu ProvinceChina Gansu Province Clinical Research Center for Functional and Molecular Imaging The Second Hospital&Clinical Medical SchoolLanzhou UniversityLanzhou 730030Gansu ProvinceChina Department of Hepatology The Second Hospital&Clinical Medical SchoolLanzhou UniversityLanzhou 730030Gansu ProvinceChina MR Scientific Marketing Siemens HealthineersXi’an 710065Shaanxi ProvinceChina

BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver ***,its diagnostic performance is inconsistent among ***,it is worth studying the diagnostic value of various diffusion models for liver fibrosis in one *** To evaluate the clinical potential of six diffusion-weighted models in liver fibrosis staging and compare their diagnostic *** This prospective study enrolled 59 patients suspected of liver disease and scheduled for liver biopsy and 17 healthy *** participants underwent multi-b value *** main DWI-derived parameters included Mono-apparent diffusion coefficient(ADC)from mono-exponential DWI,intravoxel incoherent motion model-derived true diffusion coefficient(IVIM-D),diffusion kurtosis imaging-derived apparent diffusivity(DKI-MD),stretched exponential model-derived distributed diffusion coefficient(SEM-DDC),fractional order calculus(FROC)model-derived diffusion coefficient(FROC-D)and FROC model-derived microstructural quantity(FROC-μ),and continuous-time random-walk(CTRW)model-derived anomalous diffusion coefficient(CTRW-D)and CTRW model-derived temporal diffusion heterogeneity index(CTRW-α).The correlations between DWI-derived parameters and fibrosis stages and the parameters’diagnostic efficacy in detecting significant fibrosis(SF)were assessed and *** CTRW-D(r=-0.356),CTRW-α(r=-0.297),DKI-MD(r=-0.297),FROC-D(r=-0.350),FROC-μ(r=-0.321),IVIM-D(r=-0.251),Mono-ADC(r=-0.362),and SEM-DDC(r=-0.263)were significantly correlated with fibrosis *** areas under the ROC curves(AUCs)of the combined index of the six models for distinguishing SF(0.697-0.747)were higher than each of the parameters alone(0.524-0.719).The DWI models’ability to detect SF was *** combined index of CTRW model parameters had the highest AUC(0.747).CONCLUSION The DWI models were similarly valuable in distinguishing SF in patients with liver *** combined index of CTRW paramet

关键词： Liver fibrosis Magnetic resonance imaging Diffusion-weighted magnetic resonance Liver biopsy Significant fibrosis