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A continuous and long-term in-situ stress measuring method based on fiber optic. Part I: Theory of inverse differential strain analysis

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Petroleum Science 2024年第2期21卷 1171-1189页

作者： Kun-Peng zhang Mian Chen Chang-jun Zhao Su Wang yong-Dong fan State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China MOE Key Laboratory of Petroleum Engineering in China University of Petroleum Beijing102249China Beijing International Center for Gas Hydrate School of Earth and Space SciencesPeking UniversityBeijing100871China

A method for in-situ stress measurement via fiber optics was proposed. The method utilizes the relationship between rock mass elastic parameters and in-situ stress. The approach offers the advantage of long-term stress measurements with high spatial resolution and frequency, significantly enhancing the ability to measure in-situ stress. The sensing casing, spirally wrapped with fiber optic, is cemented into the formation to establish a formation sensing nerve. Injecting fluid into the casing generates strain disturbance, establishing the relationship between rock mass properties and treatment ***, an optimization algorithm is established to invert the elastic parameters of formation via fiber optic strains. In the first part of this paper series, we established the theoretical basis for the inverse differential strain analysis method for in-situ stress measurement, which was subsequently verified using an analytical model. This paper is the fundamental basis for the inverse differential strain analysis method.

关键词： In-situ stress Fiber optic Orthotropic elastic Differential evolution ABAQUS

Asymptotic Inference in the Random Coefficient Autoregressive Model with Time-functional Variance Noises

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 320-346页

作者： En-wen ZHU Zi-wei DENG Han-jun zhang jun CAO Xiao-hui LIU Department of Mathematics and Statistics Changsha University of Science and TechnologyChangsha 410114China School of Mathematics and Computational Science Xiangtan UniversityXiangtan 411105China School of Statistics and Data Science and Key Laboratory of Data Science in Finance and EconomicsJiangxi University of Finance and EconomicsNanchang 330013China

This paper considers the random coefficient autoregressive model with time-functional variance noises,hereafter the RCA-TFV *** first establish the consistency and asymptotic normality of the conditional least squares estimator for the constant *** semiparametric least squares estimator for the variance of the random coefficient and the nonparametric estimator for the variance function are constructed,and their asymptotic results are reported.A simulation study is presented along with an analysis of real data to assess the performance of our method in finite samples.

关键词： random coefficient autoregressive model time-functional variance conditional least squares semiparametric least squares

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 135-144页

作者： Ze-Yuan Tang jun-Jie Feng jun-hui fan School of Mathematics and Information Science Guangzhou UniversityGuangzhou 510006China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Guangzhou 510006China Key Laboratory for Astronomical Observation and Technology of Guangzhou Guangzhou 510006China

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(T_s)is usually assumed to be far away from the soft X-ray,but kT_scan 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 T_scan influence the fitting results.A moderately high kT_s(around 0.03 ke V)can result in an apparent low-temperature and flat SE,while an extremely high kT_s(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),kT_sshould be treated as a free parameter with an upper limit,and an accurate coronal geometry is necessary when kT_s>0.01 ke V.

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

Tumor microenvironment-responsive arsenic-loaded layered double hydroxides film with synergistic anticancer and bactericidal activity

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Rare Metals 2024年第3期43卷 1207-1221页

作者： Shun Xing Dong-hui Wang Hai-Feng zhang Li-Dan Liu Cheng-Ce Li Chao wei jun-Yu Liu Nai-Jian Ge Xuan-yong Liu State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China Intervention Center Eastern Hepatobiliary Surgery HospitalThe Third Affiliated Hospital of Naval Medical UniversityShanghai200438China School of Health Sciences and Biomedical Engineering Hebei University of TechnologyTianjin300130China

Malignant obstruction makes gallbladder cancer have a high mortality ***-titanium alloy(nitinol)stents are commonly used as a local intervention to maximize patient survival time,but the stents lack antitumor and antibacterial capacity and are vulnerable to secondary ***-based drugs show good therapeutic promise against gallbladder *** meet clinical *** layered double hydroxides(LDHs)film is constructed on the nitinol,whose arsenite loading amounts rose by 60%after simple heat treatment compared with the conventional anion-exchange *** addition,calcination promotes the dissolution of nickel ions from the LDHs lattice,resulting in a powerful synergistic killing effect on tumor cells together with the released *** importantly,the calcined arsenic-loaded LDHs are sensitive to the acidic microenvironment of tumor tissues,which presents a much lower arsenic and nickel release amount in the normal tissues,guaranteeing its ***,the vertically sharp LDHs nanosheets can synergize with arsenic to achieve effective physical cleavage and chemical killing of adherent and planktonic *** short,we attempt to use arsenic drugs for local interventions and reasonably avoid their toxic side effects,which provides a new design idea for nitinol stents applied in the treatment of gallbladder cancer.

关键词： Nitinol Layered double hydroxides Arsenic Gallbladder cancer

Optimization of the co-closing law of guide vanes and blades for bulb turbines based on CFD

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Journal of Hydrodynamics 2024年第2期36卷 363-377页

作者： hui Liu Yun-fa Lin yong-guang Cheng Song Xue Mao-jia Tang Jian zhang Jia-yi fan State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Dongfang Electric Machinery Co. Ltd.Deyang618000China

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations,and determining appropriate closing laws of guide vanes(GVs)and runner blades(RBs)for this process is of *** this study,we proposed a procedure to optimize the co-closing law of GVs and RBs by using computational fluid dynamics(CFD),combined with the design of experiment(DOE)method,approximation model,and genetic optimization *** sensitivity of closing law parameters on the histories of head,speed,and thrust was analyzed,and a two-stage GVs’closing law associating with a linear RBs’closing law was *** results show that GVs dominate the transient characteristics by controlling the change of *** GVs’first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure;slowing GVs’second-stage closing speed is conducive to controlling the maximum reverse axial *** directly affect the runner *** RBs’closing speed can further reduce the rotational speed and the maximum reverse axial *** safety margin of each control parameter,flow patterns,and pressure pulsations of a practical hydropower station were all improved after optimization,demonstrating the effectiveness of this method.

关键词： Bulb turbine load rejection transient process double regulation closing law optimization computational fluid dynamics(CFD)

Directly predicting N2 electroreduction reaction free energy using interpretable machine learning with non-DFT calculated features

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Journal of Energy Chemistry 2024年第10期97卷 139-148页

作者： Yaqin zhang Yuhang Wang Ninggui Ma jun fan Department of Materials Science and Engineering City University of Hong Kong Center for Advanced Nuclear Safety and Sustainable Development City University of Hong Kong Department of Mechanical Engineering City University of Hong Kong

Electrocatalytic nitrogen reduction to ammonia has garnered significant attention with the blooming of single-atom catalysts（SACs）,showcasing their potential for sustainable and energy-efficient ammonia ***,cost-effectively designing and screening efficient electrocatalysts remains a *** this study,we have successfully established interpretable machine learning（ML） models to evaluate the catalytic activity of SACs by directly and accurately predicting reaction Gibbs free *** models were trained using non-density functional theory（DFT） calculated features from a dataset comprising 90 graphene-supported *** results underscore the superior prediction accuracy of the gradient boosting regression（GBR） model for both Δg（N2→NNH） and ΔG（NH2→NH3）,boasting coefficient of determination（R2） score of 0.972 and 0.984,along with root mean square error（RMSE） of 0.051 and 0.085 eV,***,feature importance analysis elucidates that the high accuracy of GBR model stems from its adept capture of characteristics pertinent to the active center and coordination environment,unveilling the significance of elementary descriptors,with the colvalent radius playing a dominant ***,Shapley additive explanations（SHAP） analysis provides global and local interpretation of the working mechanism of the GBR *** analysis identifies that a pyrrole-type coordination（flag=0）,d-orbitals with a moderate occupation（Nd=5）,and a moderate difference in covalent radius(rTM-avenear 140 pm) are conducive to achieving high ***,we extend the prediction of activity to more catalysts without additional DFT calculations,validating the reliability of our feature engineering,model training,and design *** findings not only highlight new opportunity for accelerating catalyst design using non-DFT calculated features,but also shed light on the working mechanism of "black box" ML ***,the model provides valuable guidanc

关键词： Graphene Interpretable machine learning Nitrogen reduction Non-DFT features Single-atom catalyst

Data complexity-based batch sanitization method against poison in distributed learning

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Digital Communications and Networks 2024年第2期10卷 416-428页

作者： Silv Wang Kai fan Kuan zhang hui Li Yintang Yang State Key Laboratory of Integrated Service Networks Xidian UniversityXi'an710126China Department of Electrical and Computer Engineering University of Nebraska-LincolnLincolnNE68588USA Key Lab.of the Minist.of Educ.for Wide Bandgap Semiconductor Materials and Devices Xidian UniversityXi'an710071China

The security of Federated Learning(FL)/Distributed Machine Learning(DML)is gravely threatened by data poisoning attacks,which destroy the usability of the model by contaminating training samples,so such attacks are called causative availability indiscriminate *** the problem that existing data sanitization methods are hard to apply to real-time applications due to their tedious process and heavy computations,we propose a new supervised batch detection method for poison,which can fleetly sanitize the training dataset before the local model *** design a training dataset generation method that helps to enhance accuracy and uses data complexity features to train a detection model,which will be used in an efficient batch hierarchical detection *** model stockpiles knowledge about poison,which can be expanded by retraining to adapt to new *** neither attack-specific nor scenario-specific,our method is applicable to FL/DML or other online or offline scenarios.

关键词： Distributed machine learning security Federated learning Data poisoning attacks Data sanitization Batch detection Data complexity

Unsupervised Multi-Expert Learning Model for Underwater Image Enhancement

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 708-722页

作者： Hongmin Liu Qi zhang Yufan Hu hui Zeng Bin fan the School of Intelligence Science and Technology and the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China the School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China IEEE

Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded *** methods feed the whole image directly into the model for ***,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the *** address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color ***,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater *** on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater ***,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,*** addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced *** experiments on public datasets demonstrate that our method achieves more pleasing results in vision *** metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.

关键词： Multi-expert learning underwater image enhancement unsupervised learning

Evaluation of dry eye disease symptomatology and mental health status among patients with different COVID-19 statuses

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 822-830页

作者： fang Ruan Wen-jun Kong Qian fan Hong-wei Dong wei zhang Wen-Bin wei Ying Jie Department of Ophthalmology Beijing You’an HospitalCapital Medical UniversityBeijing Infectious Eye Disease Diagnosis and Treatment CenterBeijing 100069China Beijing Tongren Eye Center Beijing Tongren HospitalCapital Medical UniversityBeijing Institute of OphthalmologyBeijing Ophthalmology and Visual Sciences Key LabBeijing 100730China Tianjin Eye Hospital Tianjin Key Lab of Ophthalmology and Visual ScienceTianjin Eye InstituteNankai University Affiliated Eye HospitalNankai University Eye InstituteNankai UniversityClinical College of OphthalmologyTianjin Medical UniversityTianjin 300020China

AIM:To evaluate dry eye disease(DED)symptomatology and mental health status in different COVID-19 ***:A cross-sectional observational design was *** 123 eligible adults(46.34%of men,age range,18-59y)with COVID-19 included in the study from August to November,*** Surface Disease Index(OSDI),Five-item Dry Eye Questionnaire(DEQ-5),Hospital Anxiety and Depression Scale(HADS),and Pittsburgh Sleep Quality Index(PSQI)were used in this ***:OSDI scores were 6.82(1.25,15.91)in asymptomatic carriers,7.35(2.50,18.38)in mild cases,and 16.67(4.43,28.04)in recurrent cases,with 30.00%,35.56%,and 57.89%,respectively evaluated as having DED symptoms(χ2=7.049,P=0.029).DEQ-5 score varied from 2.00(0,6.00)in asymptomatic carriers,3.00(0,8.00)in mild cases,and 8.00(5.00,10.00)in recurrent cases,with 27.50%,33.33%,and 55.26%,respectively assessed as having DED symptoms(χ2=8.532,P=0.014).The prevalence of clinical anxiety(50.00%)and depression(47.37%)symptoms were also significantly higher in patients with recurrent infection(χ2=24.541,P<0.001;χ2=30.871,P<0.001).Recurrent infection was a risk factor for high OSDI scores[odds ratio,2.562;95%confidence interval(CI),1.631-7.979;P=0.033]and DEQ-5 scores(odds ratio,3.353;95%CI,1.038-8.834;P=0.043),whereas having a fixed occupation was a protective factor for OSDI scores(odds ratio,0.088;95%CI,0.022-0.360;P=0.001)and DEQ-5 scores(odds ratio,0.126;95%CI,0.039-0.405;P=0.001).CONCLUSION:Patients with recurrent COVID-19 have more severe symptoms of DED,anxiety,and depression.

关键词： COVID-19 dry eye disease recurrent infection mental health