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A novel relationship between elastic modulus and void ratio associated with principal stress for coral calcareous sand

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1033-1048页

作者： ran gao Jianhong Ye State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Elastic moduli,*** modulus G and bulk modulus K,are important parameters of geotechnical materials,which are not only the indices for the evaluation of the deformation ability of soils but also the important basic parameters for the development of the constitutive models of geotechnical *** this study,a series of triaxial loading-unloading-reloading shear tests and isotropic loading-unloadingreloading tests are conducted to study several typical mechanical properties of coral calcareous sand(CCS),and the void ratio evolution during loading,unloading and *** test results show that the stress-strain curves during multiple unloading processes are almost parallel,and their slopes are much greater than the deformation modulus at the initial stage of *** relationship between the confining pressure and the volumetric strain can be defined approximately by a hyperbolic equation under the condition of monotonic loading of confining *** the condition of confining pressure unloading,the evolution of void ratio is linear in the e-lnp0 plane,and these lines are a series of almost parallel lines if there are multiple processes of *** on the experimental results,it is found that the modified Hardin formulae for the elastic modulus estimation have a significant deviation from the tested values for *** on the experimental results,it is proposed that the elastic modulus of soils should be determined by the intersection line of two spatial surfaces in the G/K-e-p’/pa space(pa:atmosphere pressure).“Ye formulation”is further proposed for the estimation of the elastic modulus of *** new estimation formulation for soil elastic modulus would provide a new method to accurately describe the mechanical behavior of granular soils.

关键词： Coral calcareous sand(CCS) Elastic shear modulus Elastic bulk modulus Triaxial test Estimation formulation Ye formulation

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Optimization study of spherical tuyere based on BP neural network and new evaluation index

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Building Simulation 2024年第2期17卷 223-234页

作者： Mengchao Liu ran gao Yi Wang Angui Li School of Building Services Science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China

The energy consumption of heating,ventilation,and air conditioning(HVAC)systems holds a significant position in building energy usage,accounting for about 65%of the total energy ***,with the advancement of building automation,the energy consumption of ventilation systems continues to *** study focuses on improving the performance of spherical tuyeres in HVAC *** primarily utilizes neural networks and multi-island genetic algorithms(MIGA)for multi-parameter *** employing methods such as structural parameterization,accurate and fast computational fluid dynamics(CFD)simulations,a minimized sample space,and a rational optimization strategy,the time cycle of the optimization process is ***,a new comprehensive evaluation index is proposed in this research to describe the performance of spherical tuyeres,which can be used to more accurately assess spherical tuyeres with different *** results show that by establishing a neural network prediction model and combining it with the multi-island genetic algorithm,a novel spherical tuyere design was successfully *** optimized novel spherical tuyeres achieved a 27.05%reduction in the spherical tuyeres effective index(STEI)compared to the traditional spherical ***,the resistance decreased by 15.68%,and the jet length increased by 7.57%.The experimental results demonstrate that our proposed optimization method exhibits high accuracy,good generalization capability,and excellent agreement at different Reynolds numbers.

关键词： spherical tuyeres STEI CFD ventilation

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A novel model to evaluate spatial structure in thinned conifer-broadleaved mixed natural forests

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Journal of Forestry Research 2023年第6期34卷 1881-1898页

作者： Hui Liu Xibin Dong Yuan Meng Tong gao Liangliang Mao ran gao Key Laboratory of Sustainable Forest Management and Environmental Microorganism Engineering of Heilongjiang Province Northeast Forestry UniversityHarbin 150040People’s Republic of China

In order to ensure the effective analysis and reconstruction of forests,it is key to ensure the quantitative description of their spatial *** this paper,a distance model for the optimal stand spatial structure based on weighted Voronoi diagrams is *** particular,we provide a novel methodological model for the comprehensive evaluation of the spatial structure of forest stands in natural mixed conifer-broadleaved forests and the formulation of management decision *** applicability of the rank evaluation and the optimal solution distance model are compared and assessed for different standard sample plots of natural mixed conifer-broadleaved *** effect of crown width on the spatial structure unit of the trees is observed to be higher than that of the diameter at breast ***,the influence of crown length is greater than that of tree *** are nine possible spatial structure units determined by the weighted Voronoi diagram for the number of neighboring trees in the central tree,with an average intersection of neighboring crowns reaching 80%.The rank rating of natural forest sample plots is correlated with the optimal solution distance model,and their results are generally consistent for natural ***,the rank rating is not able to provide a quantitative *** optimal solution distance model is observed to be more comprehensive than traditional methods for the evaluation of the spatial structure of forest *** can effectively reflect the trends in realistic stand spatial structure factors close to or far from the ideal structure point,and accurately assesses the forest spatial *** proposed optimal solution distance model improves the integrated evaluation of the spatial structure of forest stands and provides solid theoretical and technical support for sustainable forest management.

关键词： Weighted Voronoi diagram Optimal distance model Spatial structure quantifi cation Thinning intensity Conifer-broadleaved mixed natural forests

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Existence,Uniqueness and Asymptotic Behavior for the Vlasov–Poisson System with Radiation Damping

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Acta Mathematica Sinica,English Series 2017年第5期33卷 635-656页

作者： Jing CHEN Xian Wen ZHANG ran gao College of Science Zhongyuan University of Technology School of Mathematics and Statistics Huazhong University of Science and Technology

We investigate the Cauchy problem for the Vlasov–Poisson system with radiation *** virtue of energy estimate and a refined velocity average lemma, we establish the global existence of nonnegative weak solution and asymptotic behavior under the condition that initial data have finite mass and energy. Furthermore, by building a Gronwall inequality about the distance between the Lagrangian flows associated to the weak solutions, we can prove the uniqueness of weak solution when the initial data have a higher order velocity moment.

关键词： Vlasov–Poisson system radiation damping velocity averages weak solution uniqueness

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Caryophyllene-type sesquiterpenoids and α-furanones from the plant endophytic fungus Pestalotiopsis theae

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Chinese Journal of Natural Medicines 2020年第4期18卷 261-267页

作者： GUO Long-Fang LIU gao-ran LIU Ling State Key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100039China

Two new caryophyllene-type sesquiterpenoids, pestathenols A(1) and B(2) and one new α-furanone, pestatheranone A(6), along with five known compounds(3–5, 7 and 8) have been isolated from the crude extract of the plant endophytic fungus Pestalotiopsis theae. Their structures were unambiguously established by extensive spectroscopic analyses. The absolute configuration of the 5,6-diol moiety in 1 was assigned using Snatzke’s method. Compounds 1 and 2 showed weak cytotoxicity against HeLa cell line.

关键词： Structure elucidation Sesquiterpenoids Pestalotiopsis theae Cytotoxicity

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Eff ects of thinning on ecosystem carbon storage and tree-shrub-herb diversity of a low-quality secondary forest in NE China

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Journal of Forestry Research 2023年第4期34卷 977-991页

作者： Baoshan Zhang Xibin Dong Hangfeng Qu ran gao Liangliang Mao Key Laboratory of Sustainable Forest Management and Environmental Microorganism Engineering of Heilongjiang Province Northeast Forestry UniversityHarbin 150040People’s Republic of China

Thinning is a widely used forest management tool but systematic research has not been carried out to verify its eff ects on carbon storage and plant diversity at the ecosystem *** this study,the eff ect of thinning was assessed across seven thinning intensities(0,10,15,20,25,30 and 35%)in a low-quality secondary forest in NE China over a ten-year *** aff ected the carbon storage of trees,and shrub,herb,and soil layers(P<0.05).It fi rst increased and then decreased as thinning intensity increased,reaching its maximum at 30%*** storage of the soil accounted for more than 64%of the total carbon stored in the *** was highest in the upper 20-cm soil *** increased tree species diversity while decreasing shrub and herb diversities(P<0.05).Redundancy analysis and a correlation heat map showed that carbon storage of tree and shrub layers was positively correlated with tree diversity but negatively with herb diversity,indicating that the increase in tree diversity increased the carbon storage of natural forest *** thinning decreased shrub and herb diversities,it increased the carbon storage of the overall ecosystem and tree species diversity of secondary *** carbon storage and the highest tree diversity were observed at a thinning intensity of 30%.This study provides evidence for the ecological management of natural and secondary forests and improvement of ecosystem carbon sinks and biodiversity.

关键词： Thinning Carbon storage Plant diversity Forest management NE China

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Cellular and molecular characteristics of the premetastatic niches

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Animal Models and Experimental Medicine 2023年第5期6卷 399-408页

作者： Hongfei Liu Guoxin Zhang ran gao Department of Otolaryngology Head and Neck SurgeryBeijing Tongren HospitalCapital Medical UniversityBeijingChina National Human Diseases Animal Model Resource Center The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijingChina NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingChina Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases BeijingChina

The premetastatic niches(PMN)formed by primary tumor-derived molecules regulate distant organs and tissues to further favor tumor *** PMN therapy may prevent tumor metastasis in the early stages,which is becoming increasingly *** present,there is a lack of in-depth understanding of the cellular and molecular characteristics of the ***,we summarize current research advances on the cellular and molecular characteristics of the *** emphasize that PMN intervention is a potential therapeutic strategy for early prevention of tumor metastasis,which provides a promising basis for future research and clinical application.

关键词： extracellular vesicles immunosuppression premetastatic niches tumor metastasis

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An enhanced treatment of boundary conditions in implicit smoothed particle hydrodynamics

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Acta Mechanica Sinica 2014年第1期30卷 37-49页

作者： Ya-Wei Han Hong-Fu Qiang Hu Liu Wei-ran gao Xi’an Research Inst.of Hi-Tech.

In this work, an enhanced treatment of the solid boundaries is proposed for smoothed particle hydrodynamics with implicit time integration scheme （Implicit SPH）. Three types of virtual particles, i.e., boundary particles, image particles and mirror particles, are used to impose boundary conditions. Boundary particles are fixed on the solid boundary, and each boundary particle is associated with two fixed image particles inside the fluid domain and two fixed mirror particles outside the fluid domain. The image particles take the flow properties through fluid particles with moving least squares （MLS） interpolation and the properties of mirror particles can be obtained by the corresponding image particles. A repulsive force is also applied for boundary particles to prevent fluid particles from unphysical penetra- tion through solid boundaries. The new boundary treatment method has been validated with five numerical examples. All the numerical results show that Implicit SPH with this new boundary-treatment method can obtain accurate results for non-Newtonian fluids as well as Newtonian fluids, and this method is suitable for complex solid boundaries and can be easily extended to 3D problems.

关键词： Implicit SPH. Boundary conditions. Power-law model Repulsive force MLS interpolation

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Research on optimization and design methods for air distribution system based on target values

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Building Simulation 2021年第3期14卷 721-735页

作者： ran gao Hengchun Zhang Angui Li Shihao Wen Wuyi Du Baoshun Deng School of Building Services Science and Engineering Xi'an University of Architecture and TechnologyXi'an 710055China School of Thermal Engineering Shandong Jianzhu UniversityJinan 250101ShandongChina China Railway First Survey&Design Institute Group Xi'an 710043China

To achieve sufficient air conditioning of large buildings,reasonable air distribution in indoor spaces is an effective method for creating stratified air ***,optimizing the air distribution in large buildings is extremely *** this paper,we expound on a new method for air distribution design and optimization based on target value evaluation and summarize the relevant design processes based on an orthogonal test and by decoupling the effects of the size of the tuyere,airflow temperature,air-supply angle and velocity on air ***,we present a design *** optimize the distribution of a lateral air supply in winter,the deflection angle,velocity and temperature of the air supply can be determined in *** the large and tall building types addressed in this paper,the optimal air-supply angle is 2°,the optimal air-supply velocity is 8 m/s,and the optimal air-supply temperature is 19℃.

关键词： air distribution target value indicator optimization

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Research progress on the structure and function of endomucin

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Animal Models and Experimental Medicine 2020年第4期3卷 325-329页

作者： Guoxin Zhang Xingjiu Yang ran gao Key Laboratory of Human Disease Comparative Medicine(National Health and Family Planning Commission) Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences(CAMS)&Comparative Medicine CentrePeking Union Medical Collage(PUMC)BeijingPR China

Endomucin is a type I integral membrane glycoprotein,which is expressed in venous and capillary endothelial *** consists of 261 amino acids with an extracellular domain that is highly O-glycosylated at serine and threonine residues and has several potential N-glycosylation *** plays an important role in biological processes such as cell interaction,molecular cell signaling,angiogenesis and cell migration,and in recent years it has also been identified as an anti-adhesion molecule and a marker of endothelial *** it has been shown to be involved in a number of physiological and pathological mechanisms,many of its functions remain unknown,and further study is *** article reviews research progress on the function of endomucin to date,in order to provide guidance for future studies.

关键词： angiogenesis endomucin endothelial cells related markers

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