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Investigation of stress corro-sion-enhanced plastic deformation using atomic force microscope

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Chinese Science Bulletin 2002年第12期47卷 1053-1056页

作者： liang, S Qiao, LJ chu, WY Univ Sci & Technol Beijing Dept Mat Phys Beijing 100083 Peoples R China

Atomic force microscope (AFM) was used to study in situ the change in slip bands during stress corrosion of brass in the ammonia solution prior to initiation of stress corrosion crack. The result showed that additive slip bands appeared ahead of a loaded notch tip during stress corrosion prior to initiation of stress corrosion crack after the constant deflection specimen was precrept for 48 h and then polished. The average height and spacing of slip bands generated during stress corrosion were about three times less or larger, respectively, than those during loading in air.

关键词： brass stress corrosion atomic force microscope.

Reservoir of human immunodeficiency virus in the brain:New insights into the role of T cells

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BIOCELL 2023年第12期47卷 2591-2595页

作者： YINGDONG ZHANG ming chu HONGZHOU LU Department of Neurosurgery The Second Affiliated HospitalSchool of MedicineSouthern University of Science and TechnologyShenzhen518055China School of Medicine The Second Affiliated HospitalShenzhen518000China Department of Infectious Diseases National Clinical Research Center for Infectious DiseasesShenzhen Third People’s HospitalShenzhen518000China

Human immunodeficiency virus(HIV)infection of the central nervous system(CNS)has attracted significant attention because it contributes to severe complications of acquired immunodeficiency syndrome(AIDS)and seriously impairs the life quality of infected *** this review,we briefly describe the latent infection of HIV in CNS and focus on the role of the important immune cells,such as T cells,in the formation and maintenance of the HIV reservoir in *** review explores the mechanisms by which T cells enter CNS and establish latent infection of HIV in the *** conclusion,we summarize the role of these cells in the interaction between HIV and *** our better understanding of the underlying mechanisms,we propose future directions for the development of novel strategies to eliminate HIV reservoirs in the CNS based on cellular components.

关键词： Human immunodeficiency virus Central nervous system Reservoir Latent infection T cells

Sharp power mean bounds for Seiffert mean

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Applied Mathematics(A Journal of Chinese Universities) 2014年第1期29卷 101-107页

作者： LI Yong-min WANG Miao-kun chu Yu-ming School of Mathematics and Computation Science Hunan City University

In this paper, we find the greatest value p = log 2/（log Tr - log 2） = 1.53.- and the least value q -- 5/3 - 1.66.. such that the double inequality Mp（a,b）〈 T（a,b）〈 Mq（a,b） holds for all a, b 〉 0 with a # b. Here, Mp（a, b） and T（a, b） are the p-th power and Seiffertmeans of two positive numbers a and b, respectively.

关键词： power mean Seiffert mean inequality

A New Method for Determining Fluid Compositions in the H_2O-NaClCaCl_2 System with Cryogenic Raman Spectroscopy

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Acta Geologica Sinica(English Edition) 2014年第4期88卷 1169-1182页

作者： CHI Guoxiang chu Haixia Ryan SCOTT CHOU I-ming Department of Geology University of Regina Laboratory for Experimental Study Under Deep-sea Extreme Conditions Sanya Institute of Deep-sea Science and EngineeringChinese Academy of Sciences

Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.

关键词： cryogenic Raman H20-NaCl-CaCl2 XNaCI fluid inclusion

Estimation of peak relative velocity and peak absolute acceleration of linear SDOF systems

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Earthquake Engineering and Engineering Vibration 2007年第2期6卷 1-10页

作者： Jianwei Song Yi-Lun chu Zach liang George C. Lee Department of Civil Structural and Environmental Engineering University at Buffalo State University of New York USA

In the seismic analysis and design of structures, the true velocity and absolute acceleration are usually approximated by their corresponding pseudo-values. This approach is simple and works well for structures with small damping （say, less than 15%）. When the damping of a structure is enhanced for the purpose of response reduction, it may result in large analysis and design errors. Based on theory of random vibration and the established mechanism of seismic response spectra analysis, a method is developed （1） to predict the relative velocity spectra with any damping ratio level directly from the 5% standard pseudo-acceleration spectrum; and （2） to estimate the peak absolute acceleration. The accuracy of both is validated by using two selected ensembles of ground motion records.

关键词： damping device velocity spectrum absolute acceleration spectrum response spectrum analysis

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A multi-class large margin classifier

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 253-262页

作者： liang TANG Qi XUAN Rong XIONG Tie-jun WU Jian chu Institute of Cyber-Systems and Control Zhejiang University Hangzhou 310027 China

Currently there are two approaches for a multi-class support vector classifier(SVC). One is to construct and combine several binary classifiers while the other is to directly consider all classes of data in one optimization formulation. For a K-class problem(K>2),the first approach has to construct at least K classifiers,and the second approach has to solve a much larger op-timization problem proportional to K by the algorithms developed so far. In this paper,following the second approach,we present a novel multi-class large margin classifier(MLMC). This new machine can solve K-class problems in one optimization formula-tion without increasing the size of the quadratic programming(QP) problem proportional to K. This property allows us to construct just one classifier with as few variables in the QP problem as possible to classify multi-class data,and we can gain the advantage of speed from it especially when K is large. Our experiments indicate that MLMC almost works as well as(sometimes better than) many other multi-class SVCs for some benchmark data classification problems,and obtains a reasonable performance in face recognition application on the AR face database.

关键词： Multi-classification Support vector machine (SVM) Quadratic programming (QP) problem Large margin

Novel Model of Proton Exchange Membrane Fuel Cell with Predictive Control Using Hildreth Algorithm Based on Fractional-order Dynamic Model

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China Petroleum Processing & Petrochemical Technology 2024年第3期26卷 122-135页

作者： chu Kaihui Qi Zhidong Qin Hao Shan liang School of Automation Nanjing University of Science and TechnologyNanjing 210094China

Considering the multivariable and fractional-order characteristics of proton exchange membrane fuel cells(PEMFCs),a fractional-order subspace identification method(FOSIM)is proposed in this paper to establish a fractionalorder state space(FOSS)model,which can be expressed as a multivariable configuration with two inputs,hydrogenflow rate and stack current,and two outputs,cell voltage and *** on this model,a novel constrained optimal control law named the Hildreth model predictive control(H-MPC)strategy is created,which employs a Hildreth quadratic programming algorithm to adjust the output power of fuel cells through adaptively regulating hydrogen flow and stack *** semi-physical simulation results demonstrate that,compared with proportional-integral-derivative and quadratic programming MPC(QP-MPC),the proposed H-MPC exhibits better tracking ability and strong robustness against variations of PEMFC power.

关键词： PEMFC fractional-order subspace identification method fractional-order state space H-MPC

New Computation of Unified Bounds via a More General Fractional Operator Using Generalized Mittag-Leffler Function in the Kernel

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Computer Modeling in Engineering & Sciences 2021年第1期126卷 359-378页

作者： Saima Rashid Zakia Hammouch Rehana Ashraf Yu-ming chu Department of Mathematics Government College UniversityFaisalabadPakistan Division of Applied mathematics Thu Dau Mot UniversityThu Dau Mot CityVietnam Department of Mathematics Lahore CollegeWomen UniversityJhangh CampusLahorePakistan Department of Mathematics Huzhou UniversityHuzhouChina

In the present case,we propose the novel generalized fractional integral operator describing Mittag-Leffler function in their kernel with respect to another function Φ.The proposed technique is to use graceful amalgamations of the Riemann-Liouville(RL)fractional integral operator and several other fractional ***,several generalizations are considered in order to demonstrate the novel variants involving a family of positive functions n(n∈N)for the proposed fractional *** order to confirm and demonstrate the proficiency of the characterized strategy,we analyze existing fractional integral operators in terms of classical fractional ***,some special cases are apprehended and the new outcomes are also *** obtained consequences illuminate that future research is easy to implement,profoundly efficient,viable,and exceptionally precise in its investigation of the behavior of non-linear differential equations of fractional order that emerge in the associated areas of science and engineering.

关键词： Integral inequality generalized fractional integral with respect to another function increasing and decreasing functions Mittag-Leffler function

Peak earthquake response of structures under multi-component excitations

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Earthquake Engineering and Engineering Vibration 2007年第4期6卷 357-370页

作者： Jianwei Song Zach liang Yi-Lun chu George C. Lee Department of Civil Structural and Environmental Engineering State University of New York at Buffalo USA

Accurate estimation of the peak seismic responses of structures is important in earthquake resistant design. The internal force distributions and the seismic responses of structures are quite complex, since ground motions are multidirectional. One key issue is the uncertainty of the incident angle between the directions of ground motion and the reference axes of the structure. Different assumed seismic incidences can result in different peak values within the scope of design spectrum analysis for a given structure and earthquake ground motion record combination. Using time history analysis to determine the maximum structural responses excited by a given earthquake record requires repetitive calculations to determine the critical incident angle. This paper presents a transformation approach for relatively accurate and rapid determination of the maximum peak responses of a linear structure subjected to three-dimensional excitations within all possible seismic incident angles. The responses can be deformations, internal forces, strains and so on. An irregular building structure model is established using SAP2000 program. Several typical earthquake records and an artificial white noise are applied to the structure model to illustrate the variation of the maximum structural responses for different incident angles. Numerical results show that for many structural parameters, the variation can be greater than 100%. This method can be directly applied to time history analysis of structures using existing computer software to determine the peak responses without carrying out the analyses for all possible incident angles. It can also be used to verify and/or modify aseismic designs by using response spectrum analysis.

关键词： multi-component ground motion time history analysis peak structural response axis rotation