资源类型

期刊论文 77

年份

2023 5

2022 9

2021 5

2020 4

2019 5

2018 4

2017 5

2016 3

2015 4

2014 2

2013 1

2012 1

2011 2

2010 4

2009 1

2008 5

2007 2

2006 1

2005 3

2004 3

展开 ︾

关键词

元胞自动机模型 2

力学模型 2

岩石力学 2

性能化设计 2

爆炸力学 2

超光速 2

量子力学 2

4D打印 1

MCF-7细胞球 1

QCA);可逆逻辑;DG门;二进制减法器;量子成本 1

cellular automaton模型 1

miRNA簇 1

一般力学 1

上下行解耦;用户接入;资源划分;异构蜂窝网络;联合博弈 1

人员疏散 1

人员行为 1

仿真 1

传输安全 1

伪随机序列发生器 1

展开 ︾

检索范围:

排序: 展示方式:

Shape control of multi-cellular inflatable panels

N. KATAYAMA, K. ISHIMURA, K. MINESUGI, DANIEL J. INMAN

《机械工程前沿(英文)》 2013年 第8卷 第3期   页码 276-282 doi: 10.1007/s11465-013-0267-5

摘要:

Multi-cellular inflatable structures are ultra-light and robust against membrane damage such as pinholes caused by space debris. Due to their robustness, inflatable structures supported by inner gases can be applied as space structures. In the present study, shape control for a simple multi-cellular inflatable panel was achieved via a novel diaphragm mechanism. When the bending actuator in a center membrane bends, the inner pressures of sub-cells become different, and the diaphragm mechanism bends as a whole. Because a sliding component is not included, this deformable system is a reliable mechanism. In addition, the proposed mechanism has higher rigidity than that of a bending actuator used alone. In the present paper, we investigate the feasibility of a novel diaphragm mechanism and its characteristics using experimental and numerical results.

关键词: Membrane structures     inflatable structure     shape control     smart structures     structural mechanics     space engineering    

Applications of atomic force microscopy in immunology

Jiping Li, Yuying Liu, Yidong Yuan, Bo Huang

《医学前沿(英文)》 2021年 第15卷 第1期   页码 43-52 doi: 10.1007/s11684-020-0769-6

摘要: Cellular mechanics, a major regulating factor of cellular architecture and biological functions, responds to intrinsic stresses and extrinsic forces exerted by other cells and the extracellular matrix in the microenvironment. Cellular mechanics also acts as a fundamental mediator in complicated immune responses, such as cell migration, immune cell activation, and pathogen clearance. The principle of atomic force microscopy (AFM) and its three running modes are introduced for the mechanical characterization of living cells. The peak force tapping mode provides the most delicate and desirable virtues to collect high-resolution images of morphology and force curves. For a concrete description of AFM capabilities, three AFM applications are discussed. These applications include the dynamic progress of a neutrophil-extracellular-trap release by neutrophils, the immunological functions of macrophages, and the membrane pore formation mediated by perforin, streptolysin O, gasdermin D, or membrane attack complex.

关键词: cellular mechanics     atomic force microscopy     neutrophil extracellular trap     macrophage phagocytosis     pore formation    

Regulation of T cell immunity by cellular metabolism

null

《医学前沿(英文)》 2018年 第12卷 第4期   页码 463-472 doi: 10.1007/s11684-018-0668-2

摘要:

T cells are an important adaptive immune response arm that mediates cell-mediated immunity. T cell metabolism plays a central role in T cell activation, proliferation, differentiation, and effector function. Specific metabolic programs are tightly controlled to mediate T cell immune responses, and alterations in T cell metabolism may result in many immunological disorders. In this review, we will summarize the main T cell metabolic pathways and the important factors participating in T cell metabolic programming during T cell homeostasis, differentiation, and function.

关键词: T cell immunity     metabolic pathways     nutrient uptake     metabolic checkpoints    

Progressive failure analysis of notched composite plate by utilizing macro mechanics approach

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 623-642 doi: 10.1007/s11709-021-0726-8

摘要: In this study, gradual and sudden reduction methods were combined to simulate a progressive failure in notched composite plates using a macro mechanics approach. Using the presented method, a progressive failure is simulated based on a linear softening law prior to a catastrophic failure, and thereafter, sudden reduction methods are employed for modeling a progressive failure. This combination method significantly reduces the computational cost and is also capable of simultaneously predicting the first and last ply failures (LPFs) in composite plates. The proposed method is intended to predict the first ply failure (FPF), LPF, and dominant failure modes of carbon/epoxy and glass/epoxy notched composite plates. In addition, the effects of mechanical properties and different stacking sequences on the propagation of damage in notched composite plates were studied. The results of the presented method were compared with experimental data previously reported in the literature. By comparing the numerical and experimental data, it is revealed that the proposed method can accurately simulate the failure propagation in notched composite plates at a low computational cost.

关键词: progressive failure     notched composite plate     Hashin failure criterion     macro mechanics approach     finite element method    

航空航天技术与力学

陈士橹

《中国工程科学》 2003年 第5卷 第3期   页码 25-26

摘要:

文章论述了航空航天技术发展与力学学科发展的依存关系,讨论了力学学科间的交叉及交叉学科的产生,重点介绍了飞行力学与空气动力学、结构力学、一般力学、自动控制等学科间的关系,进而讨论了飞行力学的分支——弹性飞行器动力学。

关键词: 空气动力学     结构力学     一般力学     自动控制     飞行力学     弹性飞行器动力学    

Parametric sensitivity analysis of cellular diaphragm wall

Xi CHEN, Wei XU

《结构与土木工程前沿(英文)》 2012年 第6卷 第4期   页码 358-364 doi: 10.1007/s11709-012-0177-3

摘要: The deformation law of the cellular diaphragm wall in deep foundation pits was studied through numerical simulation. Based on the example of the dock wall in engineering, the full three-dimensional finite element model was used to simulate the excavation of the foundation pit. Interaction between the cellular diaphragm wall and the soil was also taken into account in the calculation. The results indicated that the maximum lateral displacement, which is the evaluation index of sensitivity analysis, appeared on the top of the interior longitudinal wall with an excavation depth of 10 m. The centrifuge model test was carried out to study the deformation regulation for a cellular diaphragm wall. The most sensitive factor was found by adjusting the length of the partition wall, the spacing of the partition wall and the thickness of the wall. In the end, a suggestion was proposed to optimize the cellular diaphragm by adjusting the length of the partition wall.

关键词: cellular diaphragm wall     sensitivity analysis     optimization     centrifuge model test    

Liver cell therapies: cellular sources and grafting strategies

《医学前沿(英文)》 2023年 第17卷 第3期   页码 432-457 doi: 10.1007/s11684-023-1002-1

摘要: The liver has a complex cellular composition and a remarkable regenerative capacity. The primary cell types in the liver are two parenchymal cell populations, hepatocytes and cholangiocytes, that perform most of the functions of the liver and that are helped through interactions with non-parenchymal cell types comprising stellate cells, endothelia and various hemopoietic cell populations. The regulation of the cells in the liver is mediated by an insoluble complex of proteins and carbohydrates, the extracellular matrix, working synergistically with soluble paracrine and systemic signals. In recent years, with the rapid development of genetic sequencing technologies, research on the liver’s cellular composition and its regulatory mechanisms during various conditions has been extensively explored. Meanwhile breakthroughs in strategies for cell transplantation are enabling a future in which there can be a rescue of patients with end-stage liver diseases, offering potential solutions to the chronic shortage of livers and alternatives to liver transplantation. This review will focus on the cellular mechanisms of liver homeostasis and how to select ideal sources of cells to be transplanted to achieve liver regeneration and repair. Recent advances are summarized for promoting the treatment of end-stage liver diseases by forms of cell transplantation that now include grafting strategies.

关键词: liver regeneration     hepatocytes     cholangiocytes     stem cells     organoids     regulatory mechanisms     transplantation/grafting strategies    

Optimization of Land-use Based on the Theory of Cellular Automata and Value of Ecosystem Services

Lian-fu Jiang,Guo-xian Xu,Hao Jiang

《工程管理前沿(英文)》 2014年 第1卷 第4期   页码 395-401 doi: 10.15302/J-FEM-2014058

摘要: The main objective of the study was to confirm the location and configuration of “Habitat Conservation Area” in Dongguan City. The land utilization condition in the target city was simulated using Arc GIS and Geo SOS software basing on multi-criteria decision model of Cellular Automata (CA). Both the simulation result and accuracy satisfied well the basic requirements. In addition to multi-criteria decision model, space optimization technique was used as well in simulation experiments.

关键词: Ecosystem service function     optimization of land use     Cellular Automata (CA)    

Creep life assessment of aero-engine recuperator based on continuum damage mechanics approach

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0702-6

摘要: The creep life of an aeroengine recuperator is investigated in terms of continuum damage mechanics by using finite element simulations. The effects of the manifold wall thickness and creep properties of brazing filler metal on the operating life of the recuperator are analyzed. Results show that the crack initiates from the brazing filler metal located on the outer surface of the manifold with the wall thickness of 2 mm and propagates throughout the whole region of the brazing filler metal when the creep time reaches 34900 h. The creep life of the recuperator meets the requirement of 40000 h continuous operation when the wall thickness increases to 3.5 mm, but its total weight increases by 15%. Decreasing the minimum creep strain rate with the enhancement of the creep strength of the brazing filler metal presents an obvious effect on the creep life of the recuperator. At the same stress level, the creep rupture time of the recuperator is enhanced by 13 times if the mismatch between the minimum creep rate of the filler and base metal is reduced by 20%.

关键词: creep     life assessment     brazed joint     continuum damage mechanics     aeroengine recuperator    

Study of the mechanics of progressive collapse of FPB isolated beam-pier substructures

Jingcai ZHANG; Yong DING; Xinchun GUAN

《结构与土木工程前沿(英文)》 2022年 第16卷 第6期   页码 718-728 doi: 10.1007/s11709-022-0815-3

摘要: The horizontal stiffness of the isolated layer is reduced substantially by a friction pendulum bearing (FPB) toprotectthe structure from potential damages caused by earthquakes. However, horizontal stiffness is essential to progressive collapse resistance of structures. This paper presents a simplified model to assess the progressive collapse response of beam-pier substructure isolated by FPB. Progressive collapse resistance by flexural action of the beam and additional resistance owing to the horizontal restraining force was achieved. The influences of the equivalent radius and friction coefficient of the FPB, the applied axial force on the FPB, and span-depth ratio of the beam on the additional resistance were investigated. Simulations were conducted to verify the proposed model. The results show that progressive collapse resistance provided by horizontal restraining can be reduced as large as 46% and 88% during compressive arching action (CAA) and catenary action (CA), respectively. The equivalent radius of the FPB shows limited effect on the progressive collapse response of FPB isolated structures, but friction coefficient and applied axial force, as well as depth ratio of the beam, show significant influences on the additional progressive collapse resistance capacity. Finite element method (FEM) results are in good agreement with the result obtained by the proposed method.

关键词: friction pendulum bearing     progressive collapse     horizontal stiffness     compressive arching action     catenary action    

Advances in structural mechanics of Chinese ancient architectures

YU Maohong, ODA Yoshiya, FANG Dongping, ZHAO Junhai

《结构与土木工程前沿(英文)》 2008年 第2卷 第1期   页码 1-25 doi: 10.1007/s11709-008-0002-1

摘要: Chinese ancient architectures are valuable heritage of ancient culture of China. Many historical building have been preserved up to now. The researches on the structural mechanics of ancient architectures show the different aspects of structure and mechanics. Systematical studies on the structural mechanics of ancient architectures have been carried out at Xi’an Jiaotong University since 1982. It is related with the need of repair of some national preservation relics in Xi’an. These studies include: 1) Ancient wooden structures including three national preservation relics Arrow Tower at North City Gate, City Tower at East City Gate, and Baogao Temple in Ningbao, Zhejiang province. 2) Ancient tall masonry building, the Big Goose Pagoda and Small Goose Pagoda in Xi’an. 3) Mechanical characteristics of ancient soil under foundation and city wall; the influence of caves in and under the ancient City Wall on the stability of the wall. 4) The typical Chinese ancient building at the center of city: the Bell Tower and Drum tower. 5) The behavior of Dou-Gong and Joggle joint of Chinese ancient wooden structure. 6) The mechanical behavior of ancient soils under complex stress state. A new systematical strength theory, the unified strength theory, is used to analyze the stability of ancient city wall in Xi’an and foundation of tall pagoda built in Tang dynasty. These researches also concern differential settlements of Arrow Tower and resistance to earthquake of these historical architecture heritages. Some other studies are also introduced. This paper gives a summary of these researches. Preservation and research are nowadays an essential requirement for the famous monuments, buildings, towers and others. Our society is more and more conscious of this necessity, which involves increasing activities of restoration, and then sometimes also of repair, mechanical strengthening and seismic retrofitting. Many historical buildings have in fact problems of structural strength and stability; the need for further studies on structural mechanics and materials is definitely growing.

Influence of construction-induced damage on the degradation of freeze–thawed lightweight cellular concrete

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 781-792 doi: 10.1007/s11709-021-0733-9

摘要: During the construction of lightweight cellular concrete (LCC), material damage frequently occurs, causing the degradation and deterioration of the mechanical performance, durability, and subgrade quality of LCC. The construction-induced damage can be more significant than those from the service environment of LCC, such as freeze–thaw (F–T) action in cold regions. However, the effect of construction-induced damage on LCC during F–T cycles is often ignored and the deterioration mechanisms are not yet clarified. In this study, we investigated the factors causing damage during construction using a sample preparation method established to simulate the damage in the laboratory setting. We conducted F–T cycle tests and microstructural characterization to study the effect of microstructural damage on the overall strength of LCC with different water contents under F–T actions. We established the relationship between the pore-area ratio and F–T cycle times, pore-area ratio, and strength, as well as the F–T cycle times and strength under different damage forms. The damage evolution is provided with the rationality of the damage equation, verified by comparing the measured and predicted damage variables. This study would serve as a guide for the construction and performance of LCC in cold regions.

关键词: lightweight cellular concrete     construction-induced damage     freeze-thaw action     microstructure     degradation mechanism    

广义塑性力学及其运用

郑颖人,孔亮

《中国工程科学》 2005年 第7卷 第11期   页码 21-36

摘要:

分析了经典塑性力学用于岩土类材料的问题,它采用了3个不符合岩土材料变形机制的假设。从固体力学原理直接导出广义塑性位势理论,将经典塑性力学改造为更一般的塑性力学——广义塑性力学。广义塑性力学采用了塑性力学中的分量理论,能反映应力路径转折的影响,并避免了采用正交流动法则所引起的过大剪胀等不合理现象,也不会产生当前非关联流动法则中任意假定塑性势面引起的误差。给出了广义塑性力学的屈服面理论、硬化定律和应力-应变关系,并建立了考虑应力主轴旋转的广义塑性位势理论。屈服条件是状态参数,也是试验参数,只能由试验给出。应用表明,广义塑性力学可作为岩土材料的建模理论,还可应用于诸如极限分析等土力学的诸多领域,具有广阔的应用前景。

关键词: 岩土塑性力学     广义塑性力学     塑性势     屈服面     本构模型    

A computational toolbox for molecular property prediction based on quantum mechanics and quantitative

《化学科学与工程前沿(英文)》 2022年 第16卷 第2期   页码 152-167 doi: 10.1007/s11705-021-2060-z

摘要: Chemical industry is always seeking opportunities to efficiently and economically convert raw materials to commodity chemicals and higher value-added chemical-based products. The life cycles of chemical products involve the procedures of conceptual product designs, experimental investigations, sustainable manufactures through appropriate chemical processes and waste disposals. During these periods, one of the most important keys is the molecular property prediction models associating molecular structures with product properties. In this paper, a framework combining quantum mechanics and quantitative structure-property relationship is established for fast molecular property predictions, such as activity coefficient, and so forth. The workflow of framework consists of three steps. In the first step, a database is created for collections of basic molecular information; in the second step, quantum mechanics-based calculations are performed to predict quantum mechanics-based/derived molecular properties (pseudo experimental data), which are stored in a database and further provided for the developments of quantitative structure-property relationship methods for fast predictions of properties in the third step. The whole framework has been carried out within a molecular property prediction toolbox. Two case studies highlighting different aspects of the toolbox involving the predictions of heats of reaction and solid-liquid phase equilibriums are presented.

关键词: molecular property     quantum mechanics     quantitative structure-property relationship     heat of reaction     solid-liquid phase equilibrium    

Macro-architectured cellular materials: Properties, characteristic modes, and prediction methods

Zheng-Dong MA

《机械工程前沿(英文)》 2018年 第13卷 第3期   页码 442-459 doi: 10.1007/s11465-018-0488-8

摘要:

Macro-architectured cellular (MAC) material is defined as a class of engineered materials having configurable cells of relatively large (i.e., visible) size that can be architecturally designed to achieve various desired material properties. Two types of novel MAC materials, negative Poisson’s ratio material and biomimetic tendon reinforced material, were introduced in this study. To estimate the effective material properties for structural analyses and to optimally design such materials, a set of suitable homogenization methods was developed that provided an effective means for the multiscale modeling of MAC materials. First, a strain-based homogenization method was developed using an approach that separated the strain field into a homogenized strain field and a strain variation field in the local cellular domain superposed on the homogenized strain field. The principle of virtual displacements for the relationship between the strain variation field and the homogenized strain field was then used to condense the strain variation field onto the homogenized strain field. The new method was then extended to a stress-based homogenization process based on the principle of virtual forces and further applied to address the discrete systems represented by the beam or frame structures of the aforementioned MAC materials. The characteristic modes and the stress recovery process used to predict the stress distribution inside the cellular domain and thus determine the material strengths and failures at the local level are also discussed.

关键词: architectured material     cellular materials     multi-scale modeling     homogenization method     effective material properties     computational method    

标题 作者 时间 类型 操作

Shape control of multi-cellular inflatable panels

N. KATAYAMA, K. ISHIMURA, K. MINESUGI, DANIEL J. INMAN

期刊论文

Applications of atomic force microscopy in immunology

Jiping Li, Yuying Liu, Yidong Yuan, Bo Huang

期刊论文

Regulation of T cell immunity by cellular metabolism

null

期刊论文

Progressive failure analysis of notched composite plate by utilizing macro mechanics approach

期刊论文

航空航天技术与力学

陈士橹

期刊论文

Parametric sensitivity analysis of cellular diaphragm wall

Xi CHEN, Wei XU

期刊论文

Liver cell therapies: cellular sources and grafting strategies

期刊论文

Optimization of Land-use Based on the Theory of Cellular Automata and Value of Ecosystem Services

Lian-fu Jiang,Guo-xian Xu,Hao Jiang

期刊论文

Creep life assessment of aero-engine recuperator based on continuum damage mechanics approach

期刊论文

Study of the mechanics of progressive collapse of FPB isolated beam-pier substructures

Jingcai ZHANG; Yong DING; Xinchun GUAN

期刊论文

Advances in structural mechanics of Chinese ancient architectures

YU Maohong, ODA Yoshiya, FANG Dongping, ZHAO Junhai

期刊论文

Influence of construction-induced damage on the degradation of freeze–thawed lightweight cellular concrete

期刊论文

广义塑性力学及其运用

郑颖人,孔亮

期刊论文

A computational toolbox for molecular property prediction based on quantum mechanics and quantitative

期刊论文

Macro-architectured cellular materials: Properties, characteristic modes, and prediction methods

Zheng-Dong MA

期刊论文