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Joint empirical likelihood confidence regions for a finite number of quantiles under strong mixing samples

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Applied Mathematics(A Journal of Chinese Universities) 2015年第1期30卷 44-54页

作者： lei qing-zhu qin yong-song Department of Mathematics Guangxi Normal University

In this paper, we obtain the joint empirical likelihood confidence regions for a finite number of quantiles under strong mixing samples. As an application of this result, the empirical likelihood confidence intervals ... 详细信息

关键词： strong mixing sample quantile confidence region blockwise empirical likelihood.

Modified likelihood ratio test for homogeneity in normal mixtures with two samples

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Applied Mathematics(A Journal of Chinese Universities) 2008年第1期23卷 113-119页

作者： qin yong-song lei qing-zhu School of Math. Sci. Guangxi Normal Univ. Guilin 541004 China.

This paper investigates the modified likelihood ratio test（LRT） for homogeneity in normal mixtures of two samples with mixing proportions unknown. It is proved that the limit distribution of the modified likelihood ... 详细信息

关键词： mixture model likelihood ratio test asymptotic distribution.

Empirical Likelihood for Response Differences in Two Linear Regression Models with Missing Data

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Acta Mathematicae Applicatae Sinica 2015年第4期31卷 963-976页

作者： yong-song qin Tao QIU qing-zhu lei Department of Mathematics Guangxi Normal University Guilin

Oonsider two linear models Xi = U＇β ＋ ei, Yj = V1/2y ＋ ηj with response variables missing at random. In this paper, we assume that X, Y are missing at random （MAR） and use the inverse probability weighted imputation to produce ＇complete＇ data sets for X and Y. Based on these data sets, we construct an empirical likelihood （EL） statistic for the difference of X and Y （denoted as A）, and show that the EL statistic has the limiting distribution of X~, which is used to construct a confidence interval for A. Results of a simulation study on the finite sample performance of EL-based confidence intervals on A are reported.

关键词： linear model inverse probability weighted imputation empirical likelihood missing at random confidence interval

Empirical Likelihood for Quantiles Under Associated Samples

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Acta Mathematicae Applicatae Sinica 2015年第1期31卷 71-80页

作者： Ying-hua LI yong-song qin qing-zhu lei School of Mathematics and Statistics Guangxi Normal University

The construction of confidence intervals for quantiles of a population under a associated sample is studied by using the blockwise technique. It is shown that the blockwise empirical likelihood （EL） ratio statistic is asymptotically X2-type distributed, which is used to obtain EL-based confidence intervals for quantiles of a population.

关键词： quantile associated sample blockwise empirical likelihood confidence interval

Bifunctional bridging capping layer enables 24.5% efficiency of perovskite solar cells with polymer-based hole transport materials

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Science China Chemistry 2025年第1期 350-359页

作者： Can zhu Yiyang Wang lei Meng Beibei Qiu Jing Li Shucheng qin Ke Hu Xin Jiang Wenbin Lai Minchao Liu Zhe Liu Chenxing Lu Jinyuan Zhang yongfang Li Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences School of Chemical Science University of Chinese Academy of Sciences Key Laboratory of Solid State Optoelectronic Devices of Zhejiang Province College of Physics and Electronic Information Engineering Zhejiang Normal University Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of Sciences Laboratory of Advanced Optoelectronic Materials College of Chemistry Chemical Engineering and Materials ScienceSoochow University

Developing a bridge capping layer between perovskite and hole transport layer materials（HTMs） in the n-i-p perovskite solar cells（pero-SCs） is an effective approach to modify the morphology of HTMs and passivate the perovskite ***, we select the quinoxaline-based bifunctional passivation agent, quinoxalin-6-yl-methylamine hydrochloride（Qx MACl）,as the bridging layer, and a D-A copolymer PBQ12 containing the same quinoxaline unit as an HTM for the n-i-p pero-SCs. Due to the π-π stacking among the common quinoxaline units in the bridge layer and HTM, Qx MACl induces the π-π stacking of the PBQ12 film and improves the film morphology of HTMs with better conductivity. Additionally, Qx MACl can effectively passivate the perovskite surface, and PBQ12 possesses appropriate energy levels and high hole mobility. The pero-SCs based on FAPbI3with PBQ12/Qx MACl treatment showed a higher power conversion efficiency（PCE） of 24.05% and outstanding stability, maintaining 95.4% and 92.1% of its initial PCE after 750 h of storage and after over 800 h of thermal annealing at 85 °C, respectively. To further enhance the PCE of the PBQ12/Qx MACl-based devices, we developed a non-metal ion dopant for the PBQ12 HTM. Through trace doping of PBQ12 HTM by the non-metal ion dopant, the PCE of the PBQ12/Qx MACl-based devices reached 25.24%（the calibrated PCE of 24.55% by the National Institute of Metrology, China）.

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Hybrid graded element model for transient heat conduction in functionally graded materials

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Acta Mechanica Sinica 2012年第1期28卷 128-139页

作者： lei-lei Cao qing-Hua qin Ning Zhao Key Laboratory for Road Construction Technology＆ Equipment of MOE Chang＇ an University 710064 Xi＇ an China Research School of Engineering Australian National UniversityCanberra ACT 0200 Australia School of Mechatronics Northwestern Polytechnical University710072 Xi＇an China

This paper presents a hybrid graded element model for the transient heat conduction problem in functionally graded materials （FGMs）. First, a Laplace transform approach is used to handle the time variable. Then, a fundamental solution in Laplace space for FGMs is constructed. Next, a hybrid graded element is formulated based on the obtained fundamental solution and a frame field. As a result, the graded properties of FGMs are naturally reflected by using the fundamental solution to interpolate the intra-element field. Further, Stefest＇s algorithm is employed to convert the results in Laplace space back into the time-space domain. Finally, the performance of the proposed method is assessed by several benchmark examples. The results demonstrate well the efficiency and accuracy of the proposed method.

关键词： Graded element model Functionally graded materials Hybrid FEM Transient heat conduction

Torsional Response Analysis of Flexible Pipe Based on Theory and Finite Element Method

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China Ocean Engineering 2023年第2期37卷 190-203页

作者： lei qing-long zhu Xiao-hua School of Mechanical Engineering Southwest Petroleum UniversityChengdu 610500China Oil and Gas Equipment Technology Sharing and Service Platform of Sichuan Province Chengdu 610500China

As key components connecting offshore floating production platforms and subsea imports, offshore flexible pipes play significant roles in oil, natural gas, and water injection. It is found that torsional failure is one of the failure modes of flexible pipes during transportation and laying. In this paper, a theoretical model(TM) of a flexible pipe section mechanics is established, in which the carcass layer and the pressure armor layer are equivalent to the orthogonal anisotropic layers due to its complex cross-section structure. The calculation results of the TM are consistent with those of a finite element model(FEM), which can accurately describe the torsional response of the flexible ***, the TM and FEM are used to discuss the influence of boundary conditions on the torsional *** structure of the flexible pipe is stable when twisted counterclockwise. However, limiting the top axial displacement can improve the axial and radial instability of the tensile armor layer when twisted clockwise. Finally, it is recommended that the flexible pipe can be kept under top fixation during service or installation to avoid torsional failure.

关键词： flexible pipe torsional response analytical model finite element model

Effect of Ni on the corrosion resistance of bridge steel in a simulated hot and humid coastal-industrial atmosphere

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 325-338页

作者： Dong-liang Li Gui-qin Fu Miao-yong zhu qing Li Cheng-xiang Yin School of Metallurgy Northeastern University

The corrosion resistance of weathering bridge steels containing conventional contents of Ni(0.20 wt%, 0.42 wt%, 1.50 wt%) and a higher content of Ni(3.55 wt%) in a simulated hot and humid coastal-industrial atmosphere was investigated by corrosion depth loss, scanning electron microscopy–energy-dispersive X-ray spectroscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical methods. The results showed that, with increasing Ni content, the mechanical properties of the bridge steel were markedly improved, the welding parameters were satisfactory at room temperature, and the corrosion resistance was enhanced. When the Ni content was low(≤0.42 wt%), the crystallization process of the corrosion products was substantially promoted, enhancing the stability of the rust layer. When the Ni content was higher(~3.55 wt%), the corrosion reaction of the steel quickly reached a balance, because the initial rapid corrosion induced the formation of a protective rust layer in the early stage. Simultaneously, NiO and NiFe_2O_4 were generated in large quantities; they not only formed a stable, compact, and continuous oxide protective layer, but also strongly inhibited the transformation process of the corrosion products. This inhibition reduced the structural changes in the rust layer, thereby enhancing the protection. However, when the Ni content ranged from 0.42 wt% to 1.50 wt%, the corrosion resistance of the bridge steel increased only slightly.

关键词： bridge steel atmospheric corrosion corrosion resistance nickel rust anti-corrosion mechanism

Effect of orbital errors on the geosynchronous circular synthetic aperture radar imaging and interferometric processing

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第5期12卷 404-416页

作者： lei-lei KOU Xiao-qing WANG Mao-sheng XIANG Jin-song CHONG Min-hui zhu National Key Laboratory of Microwave Imaging Technology Institute of Electronics Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100190 China

The geosynchronous circular synthetic aperture radar (GEOCSAR) is an innovative SAR system,which can produce high resolution three-dimensional (3D) images and has the potential to provide 3D deformation *** an orbit altitude of approximately 36 000 km,the orbit motion and orbit disturbance effects of GEOCSAR behave differently from those of the conventional spaceborne *** this paper,we analyze the effects of orbit errors on GEOCSAR imaging and interferometric ***,we present the GEOCSAR imaging geometry and the orbit errors model based on perturbation ***,we give the GEOCSAR signal formulation based on imaging geometry,and analyze the effect of the orbit error on the output focused *** interferometric processing on the 3D reconstructed images,the relationship between satellite orbit errors and the interferometric phase is *** demonstrate the effects of orbit errors on the GEOCSAR images,interferograms,and the *** conclusions are that the required relative accuracy of orbit estimation should be at centimeter level for GEOCSAR imaging at L-band,and that millimeter-scale accuracy is needed for GEOCSAR interferometric processing.

关键词： Geosynchronous circular synthetic aperture radar (GEOCSAR) Orbit error Imaging Interferometric processing