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Fractional Dynamics of Fluid-Conveying Pipes Made of Polymer-Like Materials

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Acta Mechanica Solida Sinica 2018年第2期31卷 243-258页

作者： Ye Tang Tianzhi Yang bo fang School of Mechanical and Automotive Engineering Anhui Polytechnic University School of Aerospace Engineering Shenyang Aerospace University Department of Mechanics Tianjin University School of Astronautics Harbin Institute of Technology

The fluid-conveying pipes made of polymer-like materials are widely applied in engineering fields. However, the fractional dynamics of fluid-solid interaction remain unknown. In this work, the fractional dynamics of the pipes subjected to the excitation of supporting foun- dation are studied. A new nonlinear, fractional-order dynamic model is presented. The method of multiple scales is adopted directly to solve the model for the case of primary resonances. Numerical results are presented to show the effects of fractional order, foundation vibration, and other physical parameters on the steady-state response and stability.

关键词： Fluid-conveying pipes Fractional dynamics Method of multiple scales Polymer- like materials

Hypersurfaces with Isotropic Para-Blaschke Tensor

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Acta Mathematica Sinica,English Series 2014年第7期30卷 1195-1209页

作者： Jian bo fang Kun ZHANG Department of Mathematics and Statistics Chuxiong Normal University

Let Mn be an n-dimensional submanifold without umbilical points in the （n ＋ 1）-dimen- sional unit sphere Sn＋l. Four basic invariants of Mn under the Moebius transformation group of Sn＋1 are a 1-form Ф called moebius form, a symmetric （0, 2） tensor A called Blaschke tensor, a symmetric （0, 2） tensor B called Moebius second fundamental form and a positive definite （0, 2） tensor g called Moebius metric. A symmetric （0,2） tensor D = A ＋ μB called para-Blaschke tensor, where μ is constant, is also an Moebius invariant. We call the para-Blaschke tensor is isotropic if there exists a function ,λ such that D = λg. One of the basic questions in Moebius geometry is to classify the hypersurfaces with isotropic para-Blaschke tensor. When λ is not constant, all hypersurfaces with isotropic para-Blaschke tensor are explicitly expressed in this paper.

关键词： Moebius geometry para-Blaschke tensor isotropic

Complete Hypersurfaces with Constant Laguerre Scalar Curvature in R^n

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Acta Mathematica Sinica,English Series 2016年第6期32卷 715-724页

作者： Jian bo fang Feng Jiang LI School of Mathematics and Statistics Chuxiong Normal University Department of Mathematics Yunnan Normal University

Let x ： M^n-1→ R^n be an umbilical free hypersurface with non-zero principal curvatures. Two basic invariants of M under the Laguerre transformation group of Rn are Laguerre form C and Laguerre tensor L. In this paper, we prove the following theorem： Let M be an （n-1）-dimensional （n 〉 3） complete hypersurface with vanishing Laguerre form and with constant Laguerre scalar curvature R in R^n, denote the trace-free Laguerre tensor by L = L -1/n-1tr（L）· Id. If supM ｜｜L｜｜=0,then M is Laguerre equivalent to a Laguerre isotropic hypersurface; and if supM ｜｜L^-｜｜≡√（n-1）（n-2）R/ （n-1）（n-2）（n-3） , M isLaguerre equivalent to the hypersurface x^- ： H^1× S^n-2 → R^n.

关键词： Laguerre isoparametric hypersurface Laguerre second fundamental form Laguerre metric Laguerre form parallel Laguerre form

Risk factors for Clostridioides difficile infection in children and adolescents with inflammatory bowel disease: a systematic review and meta-analysis

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World Journal of Pediatrics 2022年第1期18卷 27-36页

作者： Sheng-bo fang Yan-Qing Song Chun-Yan Zhang Li-bo Wang Department of Pharmacy First Hospital of Jilin UniversityChangchunChina Department of Pediatric Gastroenterology Unit First Hospital of Jilin University71 Xinmin StreetChangchun130021China

Background Risk factors and consequences associated with Clostridioides difficile infection(CDI)in children and adolescents with inflammatory bowel disease(IBD)are still *** conduct a systematic review and meta-analysis to assess risk factors and outcomes associated with CDI in children and adolescents with *** PubMed,EMBASE and Cochrane Library databases were searched from inception to 24th February,*** investigating risk factors,bowel surgery rate in pediatric IBD patients with and without CDI were ***-effects model was used for calculating summary ***–Ottawa scale(NOS)was used for quality *** Fourteen studies,comprising 17,114 patients,were *** was a significant association between 5-aminosalicylic acid(5-ASA)use and CDI[odds ratio(OR)=1.95,95%confidence interval(CI)1.26–3.03],with minimal heterogeneity(I^(2)=0.00%).Increased risk of active disease(OR=4.66,95%CI 2.16–10.07)were associated with CDI in those studies performed in high quality score(NOS>6)and significantly higher CDI rates in studies conducted outside USA(OR=2.94,95%CI 1.57–5.58).The bowel surgery rate in IBD with CDI was 3.8–57.1%,compared to that in IBD without CDI(0–21.3%).All studies were of moderate to high *** 5-ASA use and active disease might be risk factors associated with CDI in children and adolescents with *** surgery rates associated with CDI in IBD patients varied ***-scale clinical studies on CDI in children and adolescents with IBD are still needed to verify risk factors and outcomes.

关键词： Adolescent Children Clostridioides difficile infection Inflammatory bowel disease

Quantum effects on thermal vibration of single-walled carbon nanotubes conveying fluid

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Acta Mechanica Solida Sinica 2017年第5期30卷 550-556页

作者： Ye-Wei Zhang Lin Zhou bo fang Tian-Zhi Yang Department of Astronautics Shenyang Aerospace University Shenyang 110136 PR China Department of Mechanics Tianjin University Tianjin 300072 PR China

In this paper, we investigate the microfluid induced vibration of a nanotube in thermal environment. Attention is focused on a special case that the law of energy equipartition is unreliable unless the quantum effect is taken into account. A nonlocal luler-Bernoulli beam model is used to model the transverse vibration of a single-walled nanotube （SWCNT）. Results reveal that the root of mean squared （RMS） amplitude of thermal vibration of the fluid-conveying SWCNT predicted from the quantum theory is lower than that predicted from the law of energy equipartition. The quantum effect on the thermal vibration of the fluid-conveying SWCNT is more significant for the cases of higher-order modes, lower flow velocity, lower temperature, and lower fluid density.

关键词： Quantum effectsLaw of energy equipartitionFluid-conveying SWCNTEuler beam theoryRoot of mean-squared amplitude

Paleogeographical Distribution of Mesozoic Palaeontinidae (Insecta, Hemiptera) in China with Description of New Taxa

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Acta Geologica Sinica(English Edition) 2010年第1期84卷 31-37页

作者： WANG bo ZHANG Haichun fang Yan State Key Laboratory of Palaeobiology and Stratigraphy （Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences） Nanjing 210008 China

Until now, all Chinese palaeontinids have come from northern China and are more diverse than any other hemipterous insects in the Mesozoic. Most palaeontinids have been discovered from the area encompassing northern Hebei, the Ningcheng area of Inner Mongolia and western Liaoning. The difference in ubiquity of fossil records between northern and southern China is probably related to taphonomical and collecting bias. Records of Early and Late Jurassic palaeontinids are very scarce. The highest diversity of palaeontinid species occurs in the Middle Jurassic of Daohugou Lagerstfitte. Early Cretaceous palaeontinids of China are restricted to the typical distribution of Jehol Biota. Palaeontinodes sp. is described from the Lower Cretaceous Yixian Formation of Yangshuwanzi, Inner Mongolia and is the only Palaeontinodes specimen from the Cretaceous. Plachutella exculpta Zhang, 1997 from the Lower Jurassic Badaowan Formation of Karamai, Xinjiang is re-described and some previously reported species of this genus are discussed.

关键词： Palaeontinidae Hemiptera diversity paleogeographical distribution Mesozoic China

Modeling and analysis of cantilever beam with active-passive hybrid piezoelectric network

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Science China(Technological Sciences) 2013年第9期56卷 2326-2335页

作者： LI MingMing fang bo CAO DengQing HUANG WenHu School of Astronautics Harbin Institute of Technology

The active-passive hybrid piezoelectric network (APPN) is investigated to reduce the vibration of cantilever beam. Hamilton's principle with the Rayleigh-Ritz method is used to derive the equations of motion of the beam with the APPN. Only one piezoelectric actuator is bonded on the cantilever beam, so in the segment of the beam where the piezoelectric actuator is attached, the neutral axis is not the geometric center of the beam. This change on the neutral axis is considered in the process of deriving equations. Selecting RL circuit as passive shunt circuit, open-loop analysis is performed to gain insight into the passive damping features. Velocity feedback control is then employed to analyze the characteristics of the closed-loop system. Numerical results show that the APPN has a significant effect on vibration suppression, especially at narrow frequency bands. On this basis, variable RL circuit is proposed and analyzed for broadband vibration attenuation. Numerical simulations illustrate that this scheme is effective and feasible.

关键词： active-passive hybrid piezoelectric network active control passive shunt damping Hamilton's principle

Surfaces with Isotropic Blaschke Tensor in S^3

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Acta Mathematica Sinica,English Series 2015年第5期31卷 863-878页

作者： Feng Jiang LI Jian bo fang Lin LIANG Department of Mathematics Yunnan Normal University Department of Mathematics and statistics Chuxiong Normal University

Abstract Let M^2 be an umbilic-free surface in the unit sphere S^3. Four basic invariants of M^2 under the Moebius transformation group of S^3 are Moebius metric g, Blaschke tensor A, Moebius second fundamental form B and Moebius form φ. We call the Blaschke tensor is isotropic if there exists a smooth function λ such that A = λg. In this paper, We classify all surfaces with isotropic Blaschke tensor in S^3.

关键词： Moebius geometry Blaschke tensor isotropic

Unstable Ni leaching in MOF-derived PtNi-C catalyst with improved performance for alcohols fuel electro-oxidation

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Chinese Chemical Letters 2020年第9期31卷 2259-2262页

作者： bo fang Zong Liu Yufei Bao Ligang Feng School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Significance of unstable species leaching was for the first time demonstrated on MOF-derived catalysts by taking PtNi-C as an example,that was instructive for the relevant catalyst fabrication and performance ***-C catalyst was synthesized by combining Pt nanoparticles with Ni-BTC after annealing in the tube furnace and the unstable Ni species can be easily leached out in nitric acid,and the stable PtNi nanoparticles trapped in the graphite carbon layer were *** greatly improved catalytic ability for alcohol fuels oxidation was verified by comparing the fresh and acid leached catalysts in terms of the high peak current density,specific and mass activity and rapid charge transfer kinetics and high catalytic *** current work guides the importance of unstable assistant promoter removal for the MOF derived catalysts.

关键词： Methanol oxidation Fuel cells Electrocatalyst PtNi Metal-organic frameworks