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Microstructural evolution of titanium matrix composite coatings reinforced by in situ synthesized TiB and TiC by laser cladding

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International Journal of Minerals,Metallurgy and Materials 2010年第4期17卷 481-488页

作者： Jun li Zhi-shui Yu Hui-ping Wang Man-ping li School of Materials Engineering Shanghai University of Engineering Science Shanghai 201620 China

Titanium-based composite coatings reinforced by in situ synthesized TiB and TiC particles were successfully fabricated on Ti6Al4V by laser cladding using Ti-B_4C-Al or Ti-B_4C-C-Al powders as the precursor *** microstructural and metallographic analyses were made by X-ray diffraction（XRD）,optical microscope（OM）,scanning electron microscopy（SEM）,and electron probe microanalysis （EPMA）.The results show that the coatings are mainly composed ofα-Ti cellular dendrites and a eutectic transformation product in which a large number of coarse and fine needle-shaped TiB and a few equiaxial TiC particles are homogeneously embedded.A thin dilution zone with a thickness of about 100μm is present at the interface,and it consists of a few TiB and TiC reinforcements and a large number of lamella grains growing parallel to the heat flux direction in which a thin needle-shaped microstructure exists due to the martensitic transformation. The microstructural evolution can be divided into four stages：precipitation and growth of primaryβ-Ti phase,formation of the binary eutecticumβ-Ti＋TiB,formation of the ternary eutecticumβ-Ti＋TiB＋TiC,and solid transformation fromβ-Ti toα-Ti.

关键词： coating laser cladding in-situ synthesis microstructure

Nonlinear Branching Processes with Immigration

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Acta Mathematica Sinica,English Series 2017年第8期33卷 1021-1038页

作者： Pei-Sen li School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

The nonlinear branching process with immigration is constructed as the pathwise unique solution of a stochastic integral equation driven by Poisson random measures. Some criteria for the regularity, recurrence, ergodi... 详细信息

关键词： Nonlinear branching process immigration stochastic integral equation regularity recurrence ergodicity strong ergodicity

Understanding and optimizing the gasification of biomass waste with machine learning

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Green Chemical Engineering 2023年第1期4卷 123-133,F0004页

作者： Jie li Lanyu li Yen Wah Tong Xiaonan Wang Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore117585Singapore Department of Chemical Engineering Tsinghua UniversityBeijing100084China

Gasification is a sustainable approach for biomass waste treatment with simultaneous combustible H2-syngas ***,this thermochemical process was quite complicated with multi-phase products *** product distribution and composition also highly depend on the feedstock information and gasification *** present,it is still challenging to fully understand and optimize this *** this context,four datadriven machine learning(ML)methods were applied to model the biomass waste gasification process for product prediction and process interpretation and *** results indicated that the Gradient Boosting Regression(GBR)model showed good performance for predicting three-phase products and syngas compositions with test R^(2)of 0.82–*** GBR model-based interpretation suggested that both feed and gasification condition(including the contents of feedstock ash,carbon,nitrogen,oxygen,and gasification temperature)were important factors influencing the distribution of char,tar,and ***,it was found that a feedstock with higher carbon(>48%),lower nitrogen(<0.5%),and ash(1%–5%)contents under a temperature over 800℃could achieve a higher yield of H_(2)-rich *** was shown that the optimal conditions suggested by the model could achieve an output containing 60%–62%syngas and achieve an H_(2)yield of 44.34 mol/*** valuable insights provided from the model-based interpretation could aid the understanding and optimization of biomass gasification to guide the production of H_(2)-rich syngas.

关键词： Biomass to energy Gasification Data-driven Hydrogen Tar reduction

Some Delay Gronwall Type Inequalities on Time Scales

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Acta Mathematicae Applicatae Sinica 2015年第4期31卷 1103-1114页

作者： Wei-Nian li Department of Mathematics Binzhou University

In this paper, we investigate some delay Cronwall type inequalities on time scales by using Cron- wall＇s inequality. Our results unify and extend some delay integral inequalities and their corresponding discrete analogues. The inequalities given here can be used as handy tools in the qualitative theory of certain classes of delay dynamic equations on time scales.

关键词： time scale Cronwall's inequality delay integral inequality discrete inequality dynamic equation

Effects of dietary macronutrients and body composition on glucose homeostasis in mice

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National Science Review 2021年第1期8卷 19-29页

作者： Sumei Hu Jacques Togo Lu Wang Yingga Wu Dengbao Yang Yanchao Xu li li Baoguo li Min li Jianbo li Guanlin Wang Xueying Zhang Chaoqun Niu Mohsen Mazidi Alex Douglas John R.Speakman State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Institute of Biological and Environmental Sciences University of Aberdeen Key Laboratory of Molecular Pharmacology and Drug Evaluation (Ministry of Education of China) School of Pharmacy Yantai University School of Basic Medical Sciences University of Dali University of Chinese Academy of Sciences CAS Center for Excellence in Animal Evolution and Genetics (CCEAEG)

As a major health issue, obesity is linked with elevated risk of type 2 diabetes. However, whether disrupted glucose homeostasis is due to altered body composition alone, or whether dietary macronutrients play an additional role, independent of their impact on body composition, remains unclear. We investigated the associations between macronutrients, body composition, blood hormones and glucose homeostasis. We fed C57BL/6N mice 29 different diets with variable macronutrients for 12 weeks. After 10 weeks,intraperitoneal glucose tolerance tests were performed. Generalized linear models were generated to evaluate the impacts of macronutrients, body composition and blood hormones on glucose *** area under the glucose curve (AUC) was strongly associated with body fat mass, but not dietary macronutrients. AUC was significantly associated with fasting insulin levels. Six genes from transcriptomic analysis of epididymal white adipose tissue and subcutaneous white adipose tissue were significantly associated with AUC. These genes may encode secreted proteins that play important previously unanticipated roles in glucose homeostasis.

关键词： dietary macronutrients body fat mass fasting blood glucose glucose tolerance mice

MXenes/CNTs-based hybrids:Fabrications,mechanisms,and modification strategies for energy and environmental applications

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Nano Research 2024年第5期17卷 3429-3454页

作者： Jizhou Jiang Fangyi li Lei Ding Chengxun Zhang Arramel Xin li School of Environmental Ecology and Biological Engineering School of Chemistry and Environmental EngineeringKey Laboratory of Green Chemical Engineering Process of Ministry of EducationEngineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationNovel Catalytic Materials of Hubei Engineering Research CenterWuhan Institute of TechnologyWuhan 430205China Nano Center Indonesia Jl.PUSPIPTEK Tangerang SelatanBanten 15314Indonesia Institute of Biomass Engineering Key Laboratory of Energy Plants Resource and UtilizationMinistry of Agriculture and Rural AffairsSouth China Agricultural UniversityGuangzhou 510642China

Emerging two-dimensional(2D)layered metal carbide and nitride materials,commonly termed MXenes,are increasingly recognized for their applications across diverse fields such as energy,environment,and *** the past few years,MXenes/carbon nanotubes(CNTs)-based hybrids have attracted extensive attention as an important catalyst in energy and environmental fields,due to their superior multifunctions and mechanical *** review aims to address the fabrication strategies,the identification of the enhancement mechanisms,and recent progress regarding the design and modification of MXenes/CNTs-based hybrids.A myriad of fabrication techniques have been systematically summarized,including mechanical mixing,spray drying,three-dimensional(3D)printing,self-assembly/in-situ growth,freeze drying,templating,hydrothermal methods,chemical vapor deposition(CVD),and ***,the identification of the enhancement mechanisms was thoroughly discussed from the two dimensions of theoretical simulations and in-situ ***,the recent advancements in profound applications of MXenes/CNTs-based hybrids have also been carefully revealed,including energy storage devices,sensors,water purification systems,and microwave *** also underscore anticipated challenges related to their fabrication,structure,underlying mechanisms,modification approaches,and emergent ***,this review offers insights into prospective directions and the future trajectory for these promising *** is expected that this review can inspire new ideas or provide new research methods for future studies.

关键词： MXenes/carbon nanotubes(CNTs)-based hybrids fabrication applications modification strategies

The new RS CVn binary V1034 Her revisited and the orbital period—activity relation of short-period RS CVn binaries using photometric distortion amplitude

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Research in Astronomy and Astrophysics 2012年第4期12卷 433-442页

作者： li-Yun Zhang College of Science/Department of Physics&NAOC-GZU-Sponsored Center for Astronomy Research Guizhou UniversityGuiyang 550025China

This paper presents new CCD BV RI light curves of the newly discovered RS CVn eclipsing binary V1034 Her in 2009 and 2010, the shapes of which are different from previously published results. They show an asymmetric outside eclipse, and we try to use a spot model to explain the phenomenon. Using the Wilson-Devinney program with a one-spot or two-spot model, photometric solutions of the system and starspot parameters were derived. Comparing the two results shows that the case of two spots is more successful in reproducing light-curve distortions. Looking at all the spot longitudes, the trend is towards active longitude belts and each active longitude belt may switch. Comparing the light curves from 2009 and 2010, we can see that the light curve changes over the long time scale of a year, especially in phase 0.25. In addition, we also collected the values of the maximum amplitudes of photometric distortion of the short-period RS CVn binary. We found for the first time that there is a trend of increasing activity with decreasing orbital period. Finally, fitting all available light minimum times including our newly obtained ones with a polynomial function confirmed that the orbital period of V1034 Her increased.

关键词： stars: binaries: late-type — stars: binaries: eclipsing — stars: individuals (V1034 Her) — stars: spots

A Dispersal and Vicariance Analysis of the Genus Caragana Fabr.

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Journal of Integrative Plant Biology 2005年第8期47卷 897-904页

作者： Ming-li ZHANG Institute of Botany the Chinese Academy of Sciences Beijing 100093 China

The genus Caragana Fabr., consisting of approximately 70 species, has a temperate Asian distribution and occurs mainly in the drought and cold regions of the northwestern and southwestern Tibetan Plateau of China. The distribution pattern of the genus was investigated using dispersal-vicariance analysis （DIVA）, The results indicate that vicariance versus dispersal plays a major role in the evolution of the genus and that short-distance dispersal also exists. There is no fossil record of this genus. Therefore, Caragana is inferred as an advanced taxon in terms of its limited temperate Asian distribution. Based on the morphological variation and ecological adaptation in Caragana, the generic speciation is postulated to be related to the uplifting of the Tibetan Plateau and to the increasing arid conditions of Central Asian lands since the Neogene. The Mongolian Plateau and the Tibetan Plateau are hypothesized as the barriers of vicariance between East Asia and western Central Asia.

关键词： Caragana dispersal distribution pattern vicariance.

Precise Asymptotics in Chung's Law of the Iterated Logarithm

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Acta Mathematica Sinica,English Series 2008年第4期24卷 631-646页

作者： li Xin ZHANG Department of Mathematics Zhejiang University Hangzhou 310027 P. R. China

Let X, X1, X2,... be i.i.d, random variables with mean zero and positive, finite variance σ^2, and set Sn = X1 ＋... ＋ Xn, n≥1. The author proves that, if EX^2I{｜X｜≥t} = 0（（log log t）^-1） as t→∞, then for any a〉-1 and b〉 -1,lim ε↑1/√1＋a（1/√1＋a-ε）b＋1 ∑n=1^∞（logn）^a（loglogn）^b/nP{max κ≤n｜Sκ｜≤√σ^2π^2n/8loglogn（ε＋an）}=4/π（1/2（1＋a）^3/2）^b＋1 Г（b＋1）,whenever an = o（1/log log n）. The author obtains the sufficient and necessary conditions for this kind of results to hold.

关键词： the law of the iterated logarithm Chung's law of the iterated logarithm small deviation,i.i.d random variables