Complex Adaptive Structures最新文献_第3页

Comments on the physical basis of the active materials concept 活性物质概念的物理基础

Complex Adaptive Structures Pub Date : 2001-10-23 DOI: 10.1117/12.446780

P. Gobin, M. Salvia, L. David, M. Morin

引用次数: 0

Porphodimethenes/porphyrins: redox-switchable tetrapyrrolic macrocycles 卟二甲基/卟啉:氧化还原可切换的四吡啶大环

Complex Adaptive Structures Pub Date : 2001-10-23 DOI: 10.1117/12.446774

H. Gill, M. Harmjanz, M. J. Scott

引用次数: 0

Emergent system identification using particle swarm optimization 基于粒子群优化的紧急系统辨识

Complex Adaptive Structures Pub Date : 2001-10-23 DOI: 10.1117/12.446767

M. S. Voss, X. Feng

引用次数: 16

Finite element modeling of bone tissue stress adaptation 骨组织应力适应的有限元建模

Complex Adaptive Structures Pub Date : 2001-10-23 DOI: 10.1117/12.446772

T. Keller

{"title":"Finite element modeling of bone tissue stress adaptation","authors":"T. Keller","doi":"10.1117/12.446772","DOIUrl":"https://doi.org/10.1117/12.446772","url":null,"abstract":"The design or architecture of bone is quite complex and diverse, ranging from a very porous cellular solid (trabecular bone) to a very dense solid (cortical bone). Significant adaptations to cortical and trabecular bone mass and architecture have been observed in response to changes in stresses acting on the tissue. The purpose of this paper is to examine bone stress-adaptation schemes, including so- called self-optimization theories of bone, within two- dimensional (2D) and three-dimensional (3D) finite element modeling (FEM) domains. Stress-adaptive FEM simulations are implemented using Matlab and involve analysis of stresses and strains, followed by successive iterations with the goal to globally minimize stress-strain objective functions (strain energy density, von Mises, maximum shear) without imposing constraints other than bounds on the relative density. Both isotropic and anisotropic material properties are considered while applying time-independent loading conditions for simple geometry domains with isoparametric elements. Application of a uniform tension/shear loading to 2D rectangular domains produced heterogeneous material, complex lattice structures that were qualitatively similar to trabecular bone. Three-dimensional cantilever beam analyses using isotropic and anisotropic material properties produced density-optimized, but not necessarily stiffness and strength optimized, structures. Finite element analysis simulations can assist in understanding complex adaptive structures, including bone.","PeriodicalId":341144,"journal":{"name":"Complex Adaptive Structures","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132116000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Evolutionary computational techniques for complex adaptive structures 复杂自适应结构的进化计算技术

Complex Adaptive Structures Pub Date : 2001-10-23 DOI: 10.1117/12.446763

W. Spillman

引用次数: 0

Synthesis and characterization of novel acid-sensitive tert-butyl methacrylate and isobutyl methacrylate containing star-shaped polymers 新型星形聚合物甲基丙烯酸叔丁酯和甲基丙烯酸异丁酯的合成与表征

Complex Adaptive Structures Pub Date : 2001-10-23 DOI: 10.1117/12.446778

T. Long, L. Kilian, Zhen-he Wang, A. Esker

{"title":"Synthesis and characterization of novel acid-sensitive tert-butyl methacrylate and isobutyl methacrylate containing star-shaped polymers","authors":"T. Long, L. Kilian, Zhen-he Wang, A. Esker","doi":"10.1117/12.446778","DOIUrl":"https://doi.org/10.1117/12.446778","url":null,"abstract":"Star-shaped polymers containing poly(isobutyl methacrylate) (iBMA) and poly(tert-butyl methacrylate) (t-BMA) arms coupled to a 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA) core were synthesized using arm-first living anionic polymerization. Gel permeation chromatography (GPC) indicated that coupling efficiencies were high and coupled products exhibited a monomodal molecular weight distribution. The star-shaped polymer number--average molecular weights were 8-10 times higher than the precursor arm molecular weights. The ratio of coupling reagent to living chain end concentration controlled the molecular weight of the star-shaped polymer and the number of coupled arms. The molecular weight distributions of the star-shaped polymers ranged from 1.5-2.0. Due to the labile tertiary- butyl esters contained in the DHDMA cores, these star-shaped polymers were readily hydrolyzed in the presence of acid catalysts. For example, poly(iBMA) star-shaped polymers were hydrolytically stable at 25 degree(s)C and hydrolyzed readily at 65 degree(s)C in the presence of hydrochloric acid. In addition, the poly(t-BMA) containing star--shaped polymers degraded under similar conditions. The degradation process for the iBMA and t-BMA containing star-shaped polymers was confirmed using 1H NMR spectroscopy, and poly(iBMA)-block- poly(methacrylic acid) and poly(methacrylic acid) were obtained, respectively.","PeriodicalId":341144,"journal":{"name":"Complex Adaptive Structures","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129291917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

DNA binding of supramolecular mixed-metal complexes 超分子混合金属配合物的DNA结合

Complex Adaptive Structures Pub Date : 2001-10-23 DOI: 10.1117/12.446779

S. Swavey, Rodd Lee Williams, Z. Fang, M. Milkevitch, K. Brewer

引用次数: 1