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Study on the Bubble Growth and Departure with A Lattice Boltzmann Method

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China Ocean Engineering 2020年第1期34卷 69-79页

作者： CHEN Guo-qing HUANG Xiao WANG shi-ping kang You-wei College of shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China CIMC Offshore Co.Ltd Shenzhen 518000China

For the growth and departure of bubbles from an orifice, a free energy lattice Boltzmann model is adopted to deal with this complex multiphase flow phenomenon. A virtual layer is set at the boundary of the flow domain to deal with the no-slip boundary condition. Effects of the viscosity, surface tension, gas inertial force and buoyancy on the characteristics of bubbles when they grow and departure from an orifice in quiescent liquid are studied. The releasing period and departure diameter of the bubble are influenced by the residual gas at the orifice, and the interaction between bubbles is taken into consideration. The relations between the releasing period or departure diameter and the gravity acceleration show fair agreements with previous numerical and theoretical results. And the influence of the gas outflow velocity on bubble formation is discussed as well. For the bubbles growing in cross-flow field, effects of the cross-flow speed and the gas outflow velocity on the bubble formation are discussed, which is related to the application in ship resistance reduction. And optimal choice of the ship speed and gas outflow velocity is studied. Cases in this paper also prove that this high density ratio LBM model has its flexibility and effectiveness on multiphase flow simulations.

关键词： lattice Boltzmann method free energy model bubble growth and departure high density ratio

Long non-coding RNA NONMMUG014387 promotes Schwann cell proliferation after peripheral nerve injury

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Neural Regeneration Research 2017年第12期12卷 2084-2091页

作者： Bin Pan Zhong-ju shi Jia-yin Yan Jia-he Li shi-qing Feng Department of Orthopedics Tianjin Medical University General Hospital Tianjin China

Schwann cells play a critical role in peripheral nerve regeneration through dedifferentiation and proliferation. In a previous study, we performed microarray analysis of the sciatic nerve after injury. Accordingly, we predicted that long non-coding RNA NONMMUG014387 may promote Schwann cell proliferation after peripheral nerve injury, as bioinformatic analysis revealed that the target gene of NONMMUG014387 was collagen triple helix repeat containing 1（Cthrc1）. Cthrc1 may promote cell proliferation in a variety of cells by activating Wnt/PCP signaling. Nonetheless, bioinformatic analysis still needs to be verified by biological experiment. In this study, the candidate long non-coding RNA, NONMMUG014387, was overexpressed in mouse Schwann cells by recombinant adenovirus transfection. Plasmid p HBAd-MCMV-GFP-NONMMUG014387 and p HBAd-MCMV-GFP were transfected into Schwann cells. Schwann cells were divided into three groups： control（Schwann cells without intervention）, Ad-GFP（Schwann cells with GFP overexpression）, and Ad-NONMMUGO148387（Schwann cells with GFP and NONMMUGO148387 overexpression）. Cell Counting Kit-8 assay was used to evaluate proliferative capability of mouse Schwann cells after NONMMUG014387 overexpression. Polymerase chain reaction and western blot assay were performed to investigate target genes and downstream pathways of NONMMUG014387. Cell proliferation was significantly increased in Schwann cells overexpressing lnc RNA NONMMUG014387 compared with the other two groups. Further, compared with the control group, m RNA and protein levels of Cthrc1, Wnt5 a, ROR2, Rho A, Rac1, JNK, and ROCK were visibly up-regulated in the Ad-NONMMUGO148387 group. Our findings confirm that long non-coding RNA NONMMUG014387 can promote proliferation of Schwann cells surrounding the injury site through targeting Cthrc1 and activating the Wnt/PCP pathway.

关键词： nerve regeneration peripheral nerve injury Schwann cells long non-coding RNAs proliferation Wnt/PCP pathway Cell CountingKit-8 assay adenovirus overexpression sciatic nerve Cthrcl neural regeneration

Influences of different crossing types on dynamic response of underground cavern subjected to ground shock

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Defence Technology（防务技术） 2021年第4期17卷 1555-1571页

作者： Shao-liu Liu Yue-tang Zhao kang Hu shi-hao Wang State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjingJiangsu210007China

An intersecting cavern is a common structural form used in underground engineering,and its safety and stability performance directly control the service performance of the whole *** dynamic responses of the three kinds of crossing type(+-shaped,T-shaped,L-shaped)caverns subjected to ground shock were studied by numerical *** velocity plus force mode boundary setting method was proposed in the coupled static and dynamic analysis of a deep underground *** results show that,among the three types of crossing caverns,the+-shaped cavern is the most significantly affected by the dynamic action,followed by T-shaped,and then L-shaped *** vault settlement,straight wall deformation,vault peak particle velocity,effective plastic strain of surrounding rock,and maximum principal stress and strain at the bottom of the lining of the straight wall increase with the increase of cavern *** vault settlement,straight wall deformation,effective plastic strain of surrounding rock,and the maximum principal stress and strain at the bottom of lining to the straight wall decrease with the increase of lateral pressure coefficient,and the peak particle velocity at the vault *** variation is small compared with the change of cavern *** influence range of the underground cavern intersection is two cavern diameters from the intersection *** bottom of the straight wall at the intersection is the weak *** is suggested to thicken the support locally to improve the stability of the cavern.

关键词： Intersecting cavern Ground shock Initial ground stress Dynamic response

Effects of rosuvastatin on the production and activation of matrix metalloproteinase-2 and migration of cultured rat vascular smooth muscle cells induced by homocysteine

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第8期14卷 696-704页

作者： Ya-fei shi ju-fang CHI Wei-liang TANG Fu-kang XU Long-bin LIU Zheng JI Hai-tao LV Hang-yuan GUO Department of Cardiology Shaoxing People's Hospital Shaoxing Hospital of Zhejiang University Department of Cardiology Huai'an First People's Hospital Nanjing Medical University

Objective： To test the influence of homocysteine on the production and activation of matrix metalloproteinase-2 （MMP-2） and tissue inhibitors of matrix metalloproteinase-2 （TIMP-2） and on cell migration of cultured rat vascular smooth muscle cells （VSMCs）. Also, to explore whether rosuvastatin can alter the abnormal secretion and activation of MMP-2 and TIMP-2 and migration of VSMCs induced by homocysteine. Methods： Rat VSMCs were incubated with different concentrations of homocysteine （50-5000 μmol/L）. Western blotting and gelatin zymography were used to investigate the expressions and activities of MMP-2 and TIMP-2 in VSMCs in culture medium when induced with homocysteine for 24, 48, and 72 h. Transwell chambers were employed to test the migratory ability of VSMCs when incubated with homocysteine for 48 h. Different concentrations of rosuvastatin （10^-9-10^-5 mol/L） were added when VSMCs were induced with 1 000 pmol/L homocysteine. The expressions and activities of MMP-2 and TIMP-2 were examined after incubating for 24, 48, and 72 h, and the migration of VSMCs was also examined after incubating for 48 h. Results： Homocysteine （50-1000 μmol/L） increased the production and activation of MMP-2 and expression of TIMP-2 in a dose-dependent manner. However, when incubated with 5000 pmol/L homocysteine, the expression of MMP-2 was up-regulated, but its activity was down-regulated. Increased homocysteine-induced production and ac- tivation of MMP-2 were reduced by rosuvastatin in a dose-dependent manner whereas secretion of TIMP-2 was not significantly altered by rosuvastatin. Homocysteine （50-5000 μmol/L） stimulated the migration of VSMCs in a dose-dependent manner, but this effect was eliminated by rosuvastatin. Conclusions： Homocysteine （50-1000 μmol/L） significantly increased the production and activation of MMP-2, the expression of TIMP-2, and the migration of VSMCs in a dose-dependent manner. Additional extracellular rosuvastatin can decrease the excessive expressio

关键词： Matrix metalloproteinase-2 (MMP-2) Vascular smooth muscle cells (VSMCs) Migration Rosuvastatin Homocysteine

Materials discovery and design using machine learning

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Journal of Materiomics 2017年第3期3卷 159-177页

作者： Yue Liu Tianlu Zhao Wangwei ju Siqi shi School of Computer Engineering and Science Shanghai UniversityShanghai 200444China School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Materials Genome Institute Shanghai UniversityShanghai 200444China

The screening of novel materials with good performance and the modelling of quantitative structureactivity relationships(QSARs),among other issues,are hot topics in the field of materials *** experiments and computational modelling often consume tremendous time and resources and are limited by their experimental conditions and theoretical ***,it is imperative to develop a new method of accelerating the discovery and design process for novel ***,materials discovery and design using machine learning have been receiving increasing attention and have achieved great improvements in both time efficiency and prediction *** this review,we first outline the typical mode of and basic procedures for applying machine learning in materials science,and we classify and compare the main ***,the current research status is reviewed with regard to applications of machine learning in material property prediction,in new materials discovery and for other ***,we discuss problems related to machine learning in materials science,propose possible solutions,and forecast potential directions of future *** directly combining computational studies with experiments,we hope to provide insight into the parameters that affect the properties of materials,thereby enabling more efficient and target-oriented research on materials discovery and design.

关键词： New materials discovery Materials design Materials properties prediction Machine learning

Improved twin support vector machine

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Science China Mathematics 2014年第2期57卷 417-432页

作者： TIAN YingJie ju XuChan QI ZhiQuan shi Yong Research Center on Fictitious Economy and Data Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences College of Information Science and Technology University of Nebraska at Omaha

We improve the twin support vector machine(TWSVM)to be a novel nonparallel hyperplanes classifier,termed as ITSVM(improved twin support vector machine),for binary *** introducing the diferent Lagrangian functions for the primal problems in the TWSVM,we get an improved dual formulation of TWSVM,then the resulted ITSVM algorithm overcomes the common drawbacks in the TWSVMs and inherits the essence of the standard ***,ITSVM does not need to compute the large inverse matrices before training which is inevitable for the ***,diferent from the TWSVMs,kernel trick can be applied directly to ITSVM for the nonlinear case,therefore nonlinear ITSVM is superior to nonlinear TWSVM ***,ITSVM can be solved efciently by the successive overrelaxation(SOR)technique or sequential minimization optimization(SMO)method,which makes it more suitable for large scale *** also prove that the standard SVM is the special case of *** results show the efciency of our method in both computation time and classification accuracy.

关键词： support vector machine twin support vector machine nonparallel structural risk minimization classification

Central cell:the key to determine persistent pollen tube attraction or termination

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Science China(Life Sciences) 2024年第9期67卷 2030-2032页

作者： Jiang-Guo Meng shi-Zhen Li Hong-ju Li Center for Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation Integrative Science Center of Germplasm Creation Western China(Chongqing)Science CitySchool of Life SciencesSouthwest UniversityChongqing400715 China Key Laboratory of Seed Innovation Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Center for Molecular Agrobiology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China

Most eukaryotic species depend on sexual reproduction,characterized by fertilization,to produce a new *** process requires the transfer of sperm(male gamete),containing half of the genetic information,from the male to the egg cell(female gamete),which holds half of the maternal genome,within the female reproductive *** strategies have been evolved to ensure fertilization success in plants.

关键词： organs termination holds

Comprehensive impact of as-cast microstructure and ordered structures on formability of large-scale Fe-6.5 wt.%Si alloy ingots

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Journal of Iron and Steel Research International 2020年第2期27卷 180-187页

作者： Xiang-ju shi Yong-feng Liang shi-bo Wen Zhi-yi Ding Bao Zhang Wei Song Feng Ye State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

Large-scale Fe-6.5 wt.%Si ingot with excellent formability is required for a pilot line producing sheets through hot/cold *** variation of the as-cast microstructure,ordered structures and the formability of the Fe-6.5 wt.%Si alloy ingots with the cooling rate during casting was *** air-cooling condition,inhomogeneous microstructures with a low proportion of equiaxed grains were formed,but the formation of ordered structures was partially inhibited,especially *** microstructures with a high proportion of equiaxed grains were observed under the condition of furnace cooling,but the ordered structures were fully generated,and the degree of order is *** is generally believed that high degree of order is the main factor of brittleness,but the homogeneous microstructure(including grain morphology and size)of the furnace-cooled sample helps to improve the *** influence of these two aspects on formability is ***,the formability is tested through the flow stress during the compression and the microstructure after the *** results show that the furnace-cooled sample has better *** large-scale ingots,the control of as-cast microstructure becomes more significant than the control of degree of *** cooling during casting is important for the large-scale ingots to have good formability meeting the requirements of direct hot rolling.

关键词： Large-scale ingot Fe-6.5 wt.%Si alloy Cooling method Formability Ordered structure As-cast microstructure

An investigation on application potentiality of microstructure heat sinks with different flow topological morphology

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Science China(Technological Sciences) 2022年第12期65卷 2895-2909页

作者： YAO XiaoLe shi QianLei LIU Qian QIN Le ju Xing XU Chao Key Laboratory of Power Station Energy Transfer Conversion and System of MOE North China Electric Power UniversityBeijing 102206China

Microstructure heat sinks have great potential for high heat flux *** this paper,we compared microchannel(MC),micro-pin-fin(MPF),manifold microchannel(MMC),and manifold micro-pin-fin(MMPF)heat sinks to figure out the pros and *** flow and manifold unit models are used to study thermal and hydrodynamic *** heat sinks with different channel/fin sizes,manifold numbers,and porosities are discussed according to the pressure drop,temperature,thermal resistance,and coefficient of *** show that MMC and MMPF heat sinks are superior to MC and MPF heat sinks,and there are also differences between MMC and MMPF heat ***,the MMPF heat sink has lower maximum temperature,temperature non-uniformity,and total thermal resistance R_(tot).In contrast,the MMC heat sink has a lower pressure drop and higher *** the MMPF heat sink,at the nozzle width of 6.75μm and the MPF width of 70.71μm(porosity=0.167),it achieves the lowest total thermal resistance of R_(tot)=2.97×10^(-6)K m^(2)/*** 10^(3)W/cm^(2)heat flux,the maximum surface temperature rise is 29.74 K,and the maximum temperature difference of the heating surface is 3.15 *** research initially provides a clear reference on the selection of single-phase cooling microstructures for ultra-high heat flux dissipation.

关键词： heat sink topology manifold microchannel micro-pin-fin high heat flux