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The Asymptotic Distributions of the Largest Entries of Sample Correlation Matrices under an α-mixing Assumption

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Acta Mathematica Sinica,English Series 2022年第11期38卷 2039-2056页

作者： hao zhu Zhao Yong ZHANG School of Mathematics Jilin UniversityChangchun 130012P.R.China

Let{Xk,i;k≥1,i≥1}be an array of random variables,{Xk;k≥1}be a strictly stationaryα-mixing sequence,where Xk=(Xk,1,Xk,2,...).Let{pn;n≥1}be a sequence of positive integers such that c1≤p n n≤c2,where c1,c2>*** th... 详细信息

关键词： Sample correlation matrices α-mixing sequence Chen-Stein method

Developing Soft Sensors for Polymer Melt Index in an Industrial Polymerization Process Using Deep Belief Networks

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International Journal of Automation and computing 2020年第1期17卷 44-54页

作者： Chang-hao zhu Jie Zhang School of Engineering Merz Court Newcastle University

This paper presents developing soft sensors for polymer melt index in an industrial polymerization process by using deep belief network(DBN).The important quality variable melt index of polypropylene is hard to measure in industrial *** of online measurement instruments becomes a problem in polymer quality *** effective solution is to use soft sensors to estimate the quality variables from process *** recent years,deep learning has achieved many successful applications in image classification and speech *** as one novel technique has strong generalization capability to model complex dynamic processes due to its deep *** can meet the demand of modelling accuracy when applied to actual *** to the conventional neural networks,the training of DBN contains a supervised training phase and an unsupervised training *** mine the valuable information from process data,DBN can be trained by the process data without existing labels in an unsupervised training phase to improve the performance of *** of DBN structure is investigated in the *** modelling results achieved by DBN and feedforward neural networks are compared in this *** is shown that the DBN models give very accurate estimations of the polymer melt index.

关键词： Polymer melt index soft sensor deep learning deep belief network(DBN) unsupervised training

Aerodynamic Characteristics of Projectile with Exotic Wraparound Wings Configuration

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Journal of Harbin Institute of Technology(New Series) 2014年第3期21卷 30-37页

作者： Fu Zhang Wen-Jun Ruan hao Wang Chen-Guang zhu Meng-hua Zhang School of Energy and Power Engineering Nanjing University of Science and Technology

A projectile with exotic wraparound wings( WAW) configuration is designed to improve the finstabilized projectile shooting quality. Two fin-stabilized projectiles with the same body with and without exotic WAW configuration are simulated numerically by applying the Roe scheme. The shear-stress transport turbulence models and the lower-upper symmetric Gauss-Seidel implicit method are used to solve 3D Reynoldsaveraged Navier—Stokes equations. The differences in aerodynamic coefficients and aerodynamic characteristics of the projectiles when the Mach number varies from 0. 35 to 0. 95 are obtained,and the cause of these differences is analyzed. The calculation results indicate that the lift-to-drag ratio of the projectile significantly increases,the rolling moment decreases,and the position of the pressure center of the projectile shows relatively small changes when the exotic WAW configuration is used. Therefore,this projectile can obviously reduce rolling effect,enlarge range and improve flying stability.

关键词： exotic WAW configuration aerodynamic characteristic hybrid structure-unstructured grid overlapping grid

bmo _ρ(ω) Spaces and Riesz transforms associated to Schrdinger operators

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Science China Mathematics 2016年第10期59卷 1995-2018页

作者： zhu hua ZHANG Qian School of General Education Beijing International Studies UniversityBeijing 100024China School of Mathematical Sciences Peking UniversityBeijing 100871China

We introduce the BMO-type space bmo ρ（w） and establish the duality between h^1ρ（ω） and bmo ρ（ω）,where ω∈A1^ρ∞（R^n） and ω＇s locally behave as Muckenhoupt＇s weights but actually include them. We also give the Fefferman-Stein type decomposition of bmop（ω） with respect to Riesz transforms associated to Schrodinger operator L,where L=-△＋V is a SchrSdinger operator on R^2 （n≥3） and V is a non-negative function satisfying the reverse HSlder inequality.

关键词： bmo ρ(ω) spaces Riesz transforms Schrodinger operator

Study of DDT and its derivatives DDD, DDE adsorption and degradation over Fe-SBA-15 at low temperature

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Journal of Environmental Sciences 2012年第3期24卷 536-540页

作者： Hailin Wang hua Tian Zhengping hao Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190China

Mesoporous SBA-15 with different Fe2O3 loading were synthesized by an in-situ coating progress for removals of dichlorodiphenyl- trichloroethane （DDT） and its derivatives, i.e., 1,1-dichloro-2,2-bis-（p-chlorophenyl）ethane （DDD） and 1,1-dichloro-2,2-bis-（4-chloro -phenyl） ethane （DDE）. The results from XRD （X-ray diffractometer）, TEM （transmission electron microscopy） indicated that the iron could be well dispersed on SBA-15 within 6 wt.% Fe2O3 loading. Nitrogen adsorption-desorption tests indicated that the synthesized materials were characterized by ordered meso-structure, high surface area and large pore volume. DDTs were removed from aqueous media in 12-hr treatment and high removal efficiency of DDTs was achieved at over 94%. DDTs could be completely degraded at 350°C under the existence of SBA-15 with 4 wt.% Fe2O3 loading. The final degradation products of DDT were dichlorobenzophenone （DCB） and bis-（4-chloro-phenyl） methane （DDM）, suggesting a complete dechlorination from trichloromethyl.

关键词： DDTs SBA-15 iron adsorption catalytic dechlorination

Hybrid uncertainty-based design optimization and its application to hybrid rocket motors for manned lunar landing

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Chinese Journal of Aeronautics 2017年第2期30卷 719-725页

作者： zhu hao Tian Hui Cai Guobiao School of Aeronautics Science and Engineering Beihang University Beijing 100083 China

Design reliability and robustness are getting increasingly important for the general design of aerospace systems with many inherently uncertain design *** paper presents a hybrid uncertainty-based design optimization（UDO） method developed from probability theory and interval *** of the uncertain design parameters which have sufficient information or experimental data are classified as random variables using probability theory,while the others are defined as interval variables with interval *** a hybrid uncertainty analysis method based on Monte Carlo simulation and Taylor series interval analysis is developed to obtain the uncertainty propagation from the design parameters to system *** design optimization strategies,including deterministic design optimization（DDO）,probabilistic UDO and hybrid UDO,are applied to the conceptual design of a hybrid rocket motor（HRM） used as the ascent propulsion system in Apollo lunar *** comparison,the hybrid UDO is a feasible method and can be effectively applied to the general design of aerospace systems.

关键词： Hybrid rocket motor Hybrid uncertainty-based design optimization Manned lunar landing Uncertainty analysis

Metal-organic frameworks derived flower-like Co_3O_4/nitrogen doped graphite carbon hybrid for high-performance sodium-ion batteries

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Journal of Materials Science & Technology 2019年第1期35卷 100-108页

作者： Haifeng Xu Guang zhu Baoming hao School of Mechanical and Electronic Engineering Suzhou University Key Laboratory of Spin Electron and Nanomaterials of Anhui Higher Education Institutes Suzhou University

In this work, a novel flower-like cobalt-based metal organic frameworks(MOFs) self-assembled by Co^(2+) and nicotinic acid have been designed and synthesized. After a simple annealing treatment, Co_3O_4 nanoparticles in-situ decorating on nitrogen doped graphite carbon-sheet(Co_3O_4/NC) were obtained. The resultant Co_3O_4/NC hybrid with unique flower-like structure and ration combination of Co_3O_4 nanoparticles and nitrogen doped graphite carbon, endowing the hybrid with enhanced electrical conductivity,short ion diffusion pathways and rich porosity to the materials, which can largely alleviate the problems of Co_3O_4 such as inferior intrinsic electrical conductivity, sluggish ion kinetics and large volume change upon cycling. When evaluated as anode material for sodium-ion batteries(SIBs), the Co_3O_4/NC hybrid exhibits satisfied reversible capacity(213.9 mAh g^(-1) after 100 cycles at 0.1 A g^(-1) ), excellent rate capability(145.4 m Ah g^(-1) at 2 A g^(-1) and 130.1 mAh g^(-1) at 4 A g^(-1) ) and robust long-term cycling stability(120.1 m Ah g^(-1) after 2000 cycles at 0.5 A g^(-1) ), showing great potential for high-performance SIBs.

关键词： Co3O4/NC hybrid Metal-organic frameworks Sodium-ion batteries High-performance

Comparison of the Photo-thermal Energy Conversion Behavior of Polar Bear Hair and Wool of Sheep

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Journal of Bionic Engineering 2017年第4期14卷 616-621页

作者： hao Jia Jiansheng Guo Jingjing zhu Key Laboratory of Textile Science and Technology Ministry of Education College of Textiles Donghua University Shanghai 201620 China

The unique photo-thermal energy conversion property of polar bear hairs has long been regarded as an essential element to enable this creature to survive in extremely cold conditions. However, the relevant research was ineffectual to provide sufficient evidence of its solar energy harvesting property. In this paper, the properties of polar bear hairs were analyzed and compared systematically with those of domestic sheep wool through the measurements in the aspects of photo-thermal conversion effi- ciency, scanning electron microscope, fluorescence spectral and transmission of UV-visible spectra. Moreover, this study was much more focused on exploring ultraviolet utilization property of polar bear hair than previous research. The research results demonstrated that the photo-thermal property of polar bear hair was superior to those of wool fiber, especially in harvesting ultraviolet part. The potential benefits of this research lie in the development of bionic solar energy collective devices, especially in artificial solar energy collection fibers and textile products.

关键词： photo-thermal conversion efficiency polar bear hair sheep wool fiber ultraviolet utilization fluorescence spectra

Lower Bounds for Moments of Quadratic Twisted Self-dual GL(3)Central L-values

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Acta Mathematica Sinica,English Series 2023年第11期39卷 2139-2148页

作者： Sheng hao hua Bing Rong huaNG Data Science Institute and School of Mathematics Shandong UniversityJi’nan 250100P.R.China

In this paper,we prove the conjectured order lower bound for the k-th moment of central values of quadratic twisted self-dual GL(3)L-functions for all k≥1,based on our recent work on the twisted first moment of centr... 详细信息

关键词： GL(3)cusp form lower bound quadratic twist central value L-function