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Rare Metals 2021年第11期40卷 3279-3288页

作者： xin-Ping Hu Qing Wang Henry Hu Rui-xin Li yang Zhao Zhi-Ming Wang Bing-Rong Zhang School of Mechanical and Automotive Engineering Qilu University of TechnologyJinan 250353China Department of Mechanical University of WindsorAutomotive&MaterialsEngineering Windsor N9B 3P4Canada

To investigate the effect of yttrium(y) on microstructure refinement and mechanical properties of aluminum alloy A356.2,the different trace contents of y(0 wt%,0.025 wt%,0.050 wt%,0.075 wt%,or 0.100 wt%)were introduced into the liquid *** alloys were fabricated in a preheated permanent mold,and subsequently treated by a T6 heat *** results of tensile testing indicate that the yield strength(yS),the ultimate tensile strength(UTS) and the elongation(El) of the A356.2 alloy are improved by the y *** yS dependence on grain size for the test alloys follows the Hall-Petch equation,which gives yS=-354.1+2875.2 d^(-1/2) with a correlation of R^(2)=*** 0.050 wt%y is added,the optimum values of the yS,UTS and El are achieved after T6 heat *** secondary phases were identified by X-ray diffraction(XRD) which mainly consisted as Si,Mg2 Si and Al3 *** scanning electron microscope(SEM) and energy-dispersive spectrometer(EDS) analyses reveal the presence of the nano-sized Al3 y particles on the surface of the Si *** A356.2 alloy with the y addition is strengthened by the dendritic refinement,and the presence of the micron-and nano-sized Al3 y precipitates.

关键词： yttrium Microstructures Mechanical properties T6 heat treatment A356.2 alloy

Chung-type Law of the Iterated Logarithm on l^p-valued Gaussian Processes

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Acta Mathematica Sinica,English Series 2006年第2期22卷 551-560页

作者： Wen Sheng WANG Li xin ZHANG Department of Statistics East China Normal University Department of Mathematics Zhejiang University

By estimating small ball probabilities for l^P-valued Gaussian processes, a Chung-type law of the iterated logarithm of l^P-valued Gaussian processes is given.

关键词： Small ball probability Gaussian process Law of the iterated logarithm

Spatiotemporal Variations and Influencing Factors Analysis of PM_(2.5) Concentrations in Jilin Province,Northeast China

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Chinese Geographical Science 2018年第5期28卷 810-822页

作者： WEN xin ZHANG Pingyu LIU Daqian Northeast Institute of Geography and Agroecology Chinese Academy of Sciences

High PM_(2.5) concentrations and frequent air pollution episodes during late autumn and winter in Jilin Province have attracted attention in recent years. To describe the spatial and temporal variations of PM_(2.5) concentrations and identify the decisive influencing factors, a large amount of continuous daily PM_(2.5) concentration data collected from 33 monitoring stations over 2-year period from 2015 to 2016 were analyzed. Meanwhile, the relationships were investigated between PM_(2.5) concentrations and the land cover, socioeconomic and meteorological factors from the macroscopic perspective using multiple linear regressions(MLR) approach. PM_(2.5) concentrations across Jilin Province averaged 49 μg/m^3, nearly 1.5 times of the Chinese annual average standard, and exhibited seasonal patterns with generally higher levels during late autumn and over the long winter than the other seasons. Jilin Province could be divided into three kinds of sub-regions according to 2-year average PM_(2.5) concentration of each city. Most of the spatial variation in PM_(2.5) levels could be explained by forest land area, cultivated land area, urban greening rate, coal consumption and soot emissions of cement manufacturing. In addition, daily PM_(2.5) concentrations had negative correlation with daily precipitation and positive correlation with air pressure for each city, and the spread and dilution effect of wind speed on PM_(2.5) was more obvious at mountainous area in Jilin Province. These results indicated that coal consumption, cement manufacturing and straw burning were the most important emission sources for the high PM_(2.5) levels, while afforestation and urban greening could mitigate particulate air pollution. Meanwhile, the individual meteorological factors such as precipitation, air pressure, wind speed and temperature could influence local PM_(2.5) concentration indirectly.

关键词： particulate matter PM2.5 spatial variation temporal variation Jilin Province

Exploring a particle-size-reduction strategy of yAG:Ce phosphor via a chemical breakdown method

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Journal of Rare Earths 2021年第8期39卷 938-945页

作者： Hongren Chen Licheng Ju Li Zhang xin Wang Linbo Zhang xin Xu Lin Gao Kehui Qiu Liangjun yin School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China College of Materials and Chemistry&Chemical Engineering Chengdu University of TechnologyChengdu 610059China Department of Materials Science and Engineering University of Central FloridaOrlando 32816USA National Engineering Research Center of Electromagnetic Radiation Control Materials University of Electronic Science and Technology of ChinaChengdu 6U731China Laboratory of Materials for Energy Conversion Department of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China CNBM(Hefei)Powder Technology Equipment CO. Ltd.Hefei Cement Research&Design InstituteHefei 230026China

Particle size reduction of y_(3)Al_(5)O_(12):Ce(yAG:Ce) phosphor is highly needed for micro-LED display *** this work,size control of yAG:Ce phosphor particles is achieved via carbon coating and further heat treatment.A thin layer of carbon is deposited on the surface of yAG:Ce by chemical vapor *** the heat treatment,carbon reacts with oxygen element in the phosphor and escapes from phosphor *** reaction results in the phosphor breaking into smaller *** phosphors were characterized by laser light scattering for particle size distribution,scanning electron microscopy(SEM),transmission electron microscopy for morphologies,X-ray diffraction refinements for crystal structure and electron energy-loss spectroscopy for elemental *** is demonstrated that the median diameter(D_(50)) of the phosphor particle size is significantly reduced from 19.1 to 0.96 μm yet the photoluminescent properties have little *** carbon coating and further heat treatment method show potential application in size control of phosphors.

关键词： y_(3)Al_(5)O_(12):Ce phosphor Particle size reduction Carbon coating Rare earths

Exosomes from umbilical cord mesenchymal stromal cells promote the collagen production of fibroblasts from pelvic organ prolapse

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World Journal of Stem Cells 2024年第6期16卷 708-727页

作者： Lei-Mei Xu xin-xin yu Ning Zhang yi-Song Chen Department of Gynecology Obstetrics and Gynecology Hospital of Fudan UniversityShanghai 200011China Department of Gynecology Shanghai Key Laboratory of Female Reproductive Endocrine-related DiseasesShanghai 200011China

BACKGROUND Pelvic organ prolapse(POP)involves pelvic organ herniation into the vagina due to pelvic floor tissue laxity,and vaginal structure is an essential *** POP,the vaginal walls exhibit abnormal collagen distribution and decreased fibroblast levels and *** intricate etiology of POP and the prohibition of trans-vaginal meshes in pelvic reconstruction surgery present challenges in targeted therapy *** umbilical cord mesenchymal stromal cells(hucMSCs)present limitations,but their exosomes(hucMSC-Exo)are promising therapeutic tools for promoting fibroblast proliferation and extracellular matrix *** inflammation in POP group fibroblasts,stimulated primary fibroblast growth,and elevated collagen I(Col1)production in ***-throughput RNA-seq of fibroblasts treated with hucMSC-Exo and miRNA sequencing of hucMSC-Exo revealed that abundant exosomal miRNAs downregulated matrix metalloproteinase 11(MMP11)*** HucMSC-Exo normalized the growth and function of primary fibroblasts from patients with POP by promoting cell growth and Col1 expression in *** miRNAs in hucMSC-Exo targeted and downregulated MMP11 ***-Exo-based therapy may be ideal for safely and effectively treating POP.

关键词： Pelvic organ prolapse Exosomes Fibroblasts Human umbilical cord mesenchymal stromal cells Extracellular matrix Collagen I

Nonlinear enhanced mass sensor based on optomechanical system

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CHINESE PHySICS B 2024年第12期33卷 120303-120303页

作者： Man, xin-xin Sun, Jing Zhang, Wen-Zhao Luo, Lijuan Jin, Guangri Zhejiang Sci Tech Univ Key Lab Opt Field Manipulat Zhejiang Prov Hangzhou 310018 Peoples R China Zhejiang Sci Tech Univ Phys Dept Hangzhou 310018 Peoples R China Ningbo Univ Technol Dept Mat & Chem Engn Ningbo 315211 Peoples R China Ningbo Univ Sch Phys Sci & Technol Ningbo 315211 Peoples R China

A high-precision and tunable mass detection scheme based on a double-oscillator optomechanical system is proposed. By designating one of the oscillators as the detection port, tiny mass signals can be probed through the frequency shift of the output spectrum, utilizing the system's optomechanically induced transparency (OMIT) effect. By solving the output of the optical mode, we demonstrate that the system exhibits two OMIT windows due to the double-oscillator coupling, with one window being strongly dependent on the mass to be detected. Characterizing the spectrum around this window enables high magnification and precise detection of the input signal under nonlinear parameter conditions. Additionally, our scheme shows resilience to environmental temperature variations and drive strength perturbations.

关键词： optomechanically induced transparency optomechanical system mass sensor

Self-normalization:Taming a wild population in a heavy-tailed world

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Applied Mathematics(A Journal of Chinese Universities) 2017年第3期32卷 253-269页

作者： SHAO Qi-man ZHOU Wen-xin Department of Statistics The Chinese University of Hong Kong Department of Mathematics University of California

The past two decades have witnessed the active development of a rich probability theory of Studentized statistics or self-normalized processes, typified by Student’s t-statistic as introduced by W. S. Gosset more than a century ago, and their applications to statistical problems in high dimensions, including feature selection and ranking, large-scale multiple testing and sparse, high dimensional signal detection. Many of these applications rely on the robustness property of Studentization/self-normalization against heavy-tailed sampling distributions. This paper gives an overview of the salient progress of self-normalized limit theory, from Student’s t-statistic to more general Studentized nonlinear statistics. Prototypical examples include Studentized one- and two-sample U-statistics. Furthermore, we go beyond independence and glimpse some very recent advances in self-normalized moderate deviations under dependence.

关键词： Berry-Esseen inequality Hotelling’s T 2-statistic large deviation moderate deviation self-normalization Student’s t-statistic U-statistic

A variational formula for controlled backward stochastic partial differential equations and some application

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Applied Mathematics(A Journal of Chinese Universities) 2014年第3期29卷 295-306页

作者： MENG Qing-xin TANG Mao-ning Department of Mathematics Huzhou Teachers College School of Mathematical Sciences Fudan University

An optimal control problem for a controlled backward stochastic partial differential equation in the abstract evolution form with a Bolza type performance functional is considered. The control domain is not assumed to be convex, and all coefficients of the system are allowed to be random. A variational formula for the functional in a given control process direction is derived, by the Hamiltonian and associated adjoint system. As an application, a global stochastic maximum principle of Pontraygins type for the optimal controls is established.

关键词： Variational formula stochastic evolution equation backward stochastic evolution equation,stochastic maximum principle spike variation.

Geochemistry,Zircon U-Pb Age and Hf Isotopic Constraints on the Petrogenesis of the Silurian Rhyolites in the Loei Fold Belt and Their Tectonic Implications

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Journal of Earth Science 2016年第3期27卷 391-402页

作者： Tianyu Zhao xin Qian Qinglai Feng State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China School of Earth Sciences China University of GeosciencesWuhan 430074China

Zircon U-Pb dating, Lu-Hf isotopic and geochemical data for the Silurian rhyolites from the Loei fold belt are presented to constrain their petrogenesis and tectonic settings. The rhyolites give a weighted mean 206Pb/238 U age of 423.7±2.7 Ma, and are characterized by high SiO2, Al2O3, K2 O and low MnO, MgO and P2O5. All samples are enriched in LILEs（e.g., Ba, K, Pb） and LREEs and depleted in HFSEs（e.g., Nb, Ta, Ti） with obvious negative Eu-anomalies（δEu=0.56–0.63）. The calc-alkaline rhyolites are typical arc-related rocks. The Loei rhyolites have high A/CNK ratios（1.19–1.34） and positive εHf（t）（4.03–5.38）, which can be interpreted as partial melting of juvenile crustal materials followed by multistage melting and differentiation, similar to highly fractional I-type rocks. Combined with regional geological surveys, the Loei rhyolites should be formed in a volcanic arc environment and may be in contact with the Truong Son fold belt during the Early Paleozoic. Moreover, the Simao Block might be in contiguity with the Indochina Block during Silurian.

关键词： I-type rhyolite zircon U-Pb dating Hf isotopic composition geochemical characteristics Loei fold belt Indochina Block

Stability Characterizations of ε-isometries on Certain Banach Spaces

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Acta Mathematica Sinica,English Series 2019年第1期35卷 123-134页

作者： Li xin CHENG Long Fa SUN School of Mathematical Sciences Xiamen University

Suppose that X, y are two real Banach Spaces. We know that for a standard ε-isometry f : X → y, the weak stability formula holds and by applying the formula we can induce a closed subspace N of *. In this paper, by using again the weak stability formula, we further show a sufficient and necessary condition for a standard ε-isometry to be stable in assuming that N is w*-closed in y*.Making use of this result, we improve several known results including Figiel’s theorem in reflexive *** also prove that if, in addition, the space y is quasi-reflexive and hereditarily indecomposable, then L(f)≡span[f(X)] contains a complemented linear isometric copy of X;Moreover, if X =y, then for every e-isometry f: X → X, there exists a surjective linear isometry S:X → X such that f-S is uniformly bounded by 2ε on X.

关键词： ε-isometry stability hereditarily indecomposable space quasi-reflexive space Banach space