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Science China Mathematics 2023年第3期66卷 601-626页

作者： Mian huang yue huang Weixin Yao School of Statistics and Management Shanghai University of Finance and EconomicsShanghai 200433China Department of Statistics University of CaliforniaRiversideRiversideCA 92521USA

In this paper, we propose a new estimation method for a nonparametric hidden Markov model(HMM), in which both the emission model and the transition matrix are nonparametric, and a semiparametric HMM, in which the transition matrix is parametric while emission models are nonparametric. The estimation is based on a novel composite likelihood method, where the pairs of consecutive observations are treated as independent bivariate random variables. Therefore, the model is transformed into a mixture model, and a modified expectation-maximization(EM) algorithm is developed to compute the maximum composite *** systematically study asymptotic properties for both the nonparametric HMM and the semiparametric HMM. We also propose a generalized likelihood ratio test to choose between the nonparametric HMM and the semiparametric HMM. We derive the asymptotic distribution and prove the Wilk’s phenomenon of the proposed test statistics. Simulation studies and an application in volatility clustering analysis of the volatility index in the Chicago Board Options Exchange(CBOE) are conducted to demonstrate the effectiveness of the proposed methods.

关键词： nonparametric HMM nonhomogeneous HMM semiparametric estimate composite likelihood generalized likelihood ratio test

Hamilton-Souplet-Zhang's gradient estimates for two weighted nonlinear parabolic equations

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Applied Mathematics(A Journal of Chinese Universities) 2017年第3期32卷 353-364页

作者： MA Bing-qing huang Guang-yue Department of Mathematics Henan Normal University Xinxiang 453007 China

In this paper, we consider gradient estimates for positive solutions to the following weighted nonlinear parabolic equations on a complete smooth metric measure space with only Bakry-Émery Ricci tensor bounded below: One is $${u_t} = {\Delta _f}u + au\log u + bu$$ with a, b two real constants, and another is $${u_t} = {\Delta _f}u + \lambda {u^\alpha }$$ with λ, α two real constants. We obtain local Hamilton-Souplet-Zhang type gradient estimates for the above two nonlinear parabolic equations. In particular, our estimates do not depend on any assumption on f.

关键词： Hamilton’s gradient estimate Souplet-Zhang’s gradient estimate weighted nonlinear parabolic equation Bakry-Émery Ricci tensor

Maximum two-dimensional (u×v,4,1,3)-OOCs

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Applied Mathematics(A Journal of Chinese Universities) 2013年第3期28卷 279-289页

作者： huang yue-mei CHANG Yan-xun Institute of Mathematics Beijing Jiaotong University Mathematics Science college Inner Mongolia Normal University

Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.

关键词： maximum two-dimensional optical orthogonal code orbit.

Reliability Simulation and Design Optimization for Mechanical Maintenance

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Chinese Journal of Mechanical Engineering 2009年第4期22卷 594-601页

作者： LIU Deshun huang Liangpei yue Wenhui XU Xiaoyan Hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment Hunan University of Science and Technology Xiangtan 411201 China

Reliability model of a mechanical product system will be newly reconstructed and maintenance cost will increase because failed parts can be replaced with new components during service, which should be accounted for in system design. In this paper, a reliability model and reliability-based design optimization methodology for maintenance are presented. First, based on the time-to-failure density function of the part of the system, the age distributions of all parts of the system during service are investigated, a reliability model of the mechanical system for maintenance is developed. Then, reliability simulations of the systems with WeibuU probability density functions are performed, the system minimum reliability and steady reliability for maintenance are defined based on reliability simulation during the life cycle of the system. Thirdly, a maintenance cost model is developed based on replacement rates of the parts, a reliability-based design optimization model for maintenance is presented, in which total life cycle cost is considered as design objective and system reliability as design constrain. Finally, the reliability-based design optimization methodology for maintenance is used to design of a link ring for the chain conveyor, which shows that optimal design with the lowest maintenance cost can be obtained, and minimum reliability and steady reliability of the system can satisfy requirement of system reliability during service of the chain conveyor.

关键词： maintenance reliability simulation design optimization

Nanoencapsulation of hexavalent chromium with nanoscale zero-valent iron:High resolution chemical mapping of the passivation layer

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Journal of Environmental Sciences 2018年第5期30卷 4-13页

作者： Xiao-yue huang Lan Ling Wei-xian Zhang State Key Laboratory for Pollution Control College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Solid phase reactions of Cr（Ⅵ） with Fe（0） were investigated with spherical-aberration-corrected scanning transmission electron microscopy（Cs-STEM） integrated with X-ray energy-dispersive spectroscopy（XEDS）. Near-atomic resolution elemental mappings of Cr（Ⅵ）–Fe（0） reactions were acquired. Experimental results show that rate and extent of Cr（Ⅵ） encapsulation are strongly dependent on the initial concentration of Cr（Ⅵ） in solution. Low Cr loading in nZⅥ（〈1.0 wt%） promotes the electrochemical oxidation and continuous corrosion of n ZⅥ while high Cr loading（〉1.0 wt%） can quickly shut down the Cr uptake. With the progress of iron oxidation and dissolution, elements of Cr and O counter-diffuse into the nanoparticles and accumulate in the core region at low levels of Cr（Ⅵ）（e.g., 〈 10 mg/L）. Whereas the reacted n ZⅥ is quickly coated with a newly-formed layer of 2–4 nm in the presence of concentrated Cr（Ⅵ）（e.g., 〉 100 mg/L）. The passivation structure is stable over a wide range of pH unless pH is low enough to dissolve the passivation layer. X-ray photoelectron spectroscopy（XPS） depth profiling reconfirms that the composition of the newly-formed surface layer consists of Fe（Ⅲ）–Cr（Ⅲ）（oxy）hydroxides with Cr（Ⅵ） adsorbed on the outside surface. The insoluble and insulating Fe（Ⅲ）–Cr（Ⅲ）（oxy）hydroxide layer can completely cover the n ZⅥ surface above the critical Cr loading and shield the electron transfer. Thus, the fast passivation of nZⅥ in high Cr（Ⅵ） solution is detrimental to the performance of nZⅥ for Cr（Ⅵ） treatment and remediation.

关键词： Nanoscale zero-valent iron (nZVI) Hexavalent chromium Solid phase reaction Passivation Spherical-aberration-correctedscanning transmission electronmicroscopy (Cs-STEM)

Genotoxins exaggerate the stressed state of aneuploid embryonic stem cells via activation of autophagy

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Science China(Life Sciences) 2020年第7期63卷 1026-1036页

作者： Meili Zhang Rong Xiao Guang Liu yue huang State Key Laboratory of Medical Molecular Biology Institute of Basic Medical SciencesChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100005China Department of Medical Genetics Institute of Basic Medical SciencesChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100005China

The cellular consequences of aneuploidy are largely dependent on the cell types examined. Aneuploid yeasts and mouse embryonic fibroblasts exhibit cell proliferation defects and can be selectively inhibited by compounds that cause proteotoxic or energy stress. By contrast, most aneuploid pluripotent stem cells proliferate rapidly and reach higher saturation densities. The responses of aneuploid pluripotent stem cells to the stress-inducing compounds remain uncharacterized. Here, we tested the response of aneuploid embryonic stem cells to several compounds that caused proteotoxic, energy and genotoxic stress using previously established mouse embryonic stem cell lines trisomic for chromosome 6, 8, 11, or 15. Not all trisomic embryonic stem cells were selectively inhibited by compounds that cause proteotoxic or energy stress. However, most of these cells exhibited increased sensitivity to genotoxins. They displayed elevated DNA damage response as characterized by increased γH2A.X foci under genotoxic stress. Further investigations indicated that elevated autophagy levels might contribute to the increased cytotoxic effects of genotoxins on trisomic embryonic stem cells. Our study laid the foundation for eliminating aneuploidy that might be an effective approach for controlling cancer progression.

关键词： aneuploidy embryonic stem cells genotoxins autophagy

Counterion-Mediated Hydrogen Bonding Making Strong Polyelectrolytes pH-Responsive:Current Understanding and Perspectives

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Chinese Journal of Polymer Science 2024年第9期42卷 1270-1277,I0005页

作者： yue huang Guang-Tao Mei Zan Hua Guang-Ming Liu Hefei National Research Center for Physical Sciences at the Microscale Department of Chemical PhysicsKey Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesUniversity of Science and Technology of ChinaHefei230026China The Key Laboratory of Functional Molecular Solids Ministry of Educationand Department of Materials ChemistrySchool of Chemistry and Materials ScienceAnhui Normal UniversityWuhu214002China

The counterion-mediated hydrogen bonding(CMHB)is related to the hydrogen bonding between bound counterions and polyelectrolyte chains in polyelectrolyte systems,where the counterions can both electrostatically bind to the charged groups of polyelectrolyte chains and act as hydrogen bond donors or acceptors to form hydrogen bonds with the hydrogen bond sites associated with polyelectrolyte chains simultaneously.A large number of literatures illustrate that strong polyelectrolytes(SPs)are insensitive to pH,which severely limmits the applications of SPs as smart ***,our studies have demonstrated that the CMHB makes SPs *** perspective discusses the mechanism of pH responsiveness of SPs and the pH-tunable properties of SPs,based on the pH-controlled CMHB *** future research directions on the pH responsiveness of SPs are also discussed *** is anticipated that the study of the pH responsiveness of SPs not only will provide a new understanding of the fundamental properties of SPs,but also will greatly expand the applications of SPs in the field of smart materials.

关键词： Counterion binding Hydrogen bond Polyelectrolyte brush Polyelectrolyte complexation

The protective effect of zeaxanthin on human limbal and conjunctival epithelial cells against UV-induced cell death and oxidative stress

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International Journal of Ophthalmology(English edition) 2019年第3期12卷 369-374页

作者： yue huang Chun Shi Jing Li Department of Ophthalmology Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Department of Ophthalmology Xinhua Hospital Chong Ming Branch Shanghai Jiao Tong University School of Medicine Department of Ophthalmology Jiangwan Hospital of Hongkou District

AIM: To explore the protective effect of zeaxanthin on human limbal and conjunctival epithelial cells against UVradiation and excessive oxidative ***: Human limbal and conjunctival epithelial cells were isolated from cadaver and cultured in vitro. They were challenged with UVB radiation and H2 O2 with and without zeaxanthin pretreatment. Cell viability, p38 and c-JUN NH(2)-terminal kinase(JNK) phosphorylation, IL-6, IL-8 and MCP-1 secretion and malondialdehyde(MDA) content were ***: Zeaxanthin had no measurable cytotoxicity on limbal or conjunctival epithelial cells when used at concentrations of 5 μg/mL and below. At 30 mJ/cm2 UVB, the pretreatment of zeaxanthin increased the percentage of live cells from 50% to 69%(P=0.01) and from 66% to 75%(P=0.05) for limbal and conjunctival epithelial cells, respectively. The concentrations of IL-6, IL-8 and MCP-1 in the culture medium reduced to 66%(for IL-6 and MCP-1)and 56%(for IL-8) of the levels without zeaxanthin. This was accompanied by reduced p38 and JNK protein phosphorylation. Pretreatment of zeaxanthin also reduced intracellular MDA content caused by H2 O2 stimulation from 0.86 μmol/L to 0.52 μmol/L(P=0.02) in limbal epithelial cells and from 0.96 μmol/L to 0.56 μmol/L in conjunctival epithelial cells(P=0.03). However, zeaxanthin did nothave significant effect on H2 O2-induced cell death in limbal or conjunctival epithelial ***: Zeaxanthin is an effective reagent in reducing the detrimental effect of UV-radiation and oxidative stress on ocular surface epithelial cells.

关键词： zeaxanthin UV-radiation oxidative stress malondialdehyde limbal epithelial cells conjunctival epithelial cells

An integrated model for structure optimization and technology screening of urban wastewater systems

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Frontiers of Environmental Science & Engineering 2015年第6期9卷 1036-1048页

作者： yue huang Xin DONG Siyu ZENG Jining CHEN School of Environment Tsinghua University Beijing 100084 China

The conventional approach to wastewater system design and planning considers each component separately and does not provide the optimum performance of the entire system. However, the growing concern for environmental protection, economic efficiency, and sus- tainability of urban wastewater systems requires an integrated modeling of subsystems and a synthetic evaluation of multiple objectives. In this study, a multi- objective optimization model of an integrated urban wastewater system was developed. The model encom- passes subsystems, such as a sewer system, stormwater management, municipal wastewater treatment, and a wastewater reclamation system. The non-dominated sort- ing genetic algorithm （NSGA-II） was used to generate a range of system design possibilities to optimize conflicting environmental and economic objectives. Information from a knowledge base, which included rules for generating treatment trains as well as the performance characteristics of commonly used water pollution control measures, was utilized. The trade-off relationships between the objec- tives, total water pollution loads to the environment, and life cycle costs （which consist of investment as well as operation and maintenance costs）, can be illustrated using Pareto charts. The developed model can be used to assist decision makers in the preliminary planning of system structure. A benchmark city was constructed to illustrate the methods of multi-objective controls, highlight cost- effective water pollution control measures, and identify the main pressures on urban water environment.

关键词： urban wastewater system integrated model-ing multi-objective optimization non-dominated sortinggenetic algorithm (NSGA-I1)

Randomized,double-blind,parallel-controlled clinical trial on correspondence of prescriptions and Traditional Chinese Medicine syndrome of ischemic stroke

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Journal of Traditional Chinese Medicine 2012年第3期32卷 335-342页

作者： Ying Gao Haizhen Zhong Bin Ma yue huang Department of Neurology Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine Beijing 100700 China National Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal University Beijing100700 China

OBJECTIVE:To investigate the effect of correspondence of prescriptions and the traditional Chinese medicine(TCM) syndrome of ischemic ***:Based on standard syndrome diagnosis and a series of effective formulas,a randomized,double-blind,parallel-controlled clinical trial on correspondence of prescriptions and the TCM syndrome of ischemic stroke was *** formulas were dynamically changed according to the patient's TCM ***:The treatment was composed of a series of formulas changed daily according to the TCM *** which were composed of a series of formulas had similar short-term(1 month after onset) effects in improving mild and moderate neurological deficits compared with treatments composed of only one ***,patients treated with a series of formulas showed improved subjective symptoms in the short-term and a decreased risk of stroke recurrence within three months after ***:Complete(series of formulas) and incomplete(only one formula) correspondence of prescriptions and TCM syndrome have similar effects on the central clinical manifestation of ischemic stroke,such as neurological deficit and activities in daily ***,they have significant differences regarding individual dysfunctions,such as subjective symptoms.

关键词： Stroke Classical prescriptions Symptom complex Multicenter study