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地方性形成过程中结构性动力与非结构性动力的关系——以曲阜地方性塑造过程为例 被引量:16
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作者 唐顺英 周尚意 刘丰祥 《地理与地理信息科学》 CSCD 北大核心 2015年第6期120-124,共5页
地方性是指一个地方区别于其他地方的独特性。结构主义地理学者认为,结构性动力机制决定了某个地方在空间网络中的功能和地位,他们强调结构性动力机制的决定作用。然而后结构主义地理学者认为,尽管存在强大的结构力量,但是个体的能动作... 地方性是指一个地方区别于其他地方的独特性。结构主义地理学者认为,结构性动力机制决定了某个地方在空间网络中的功能和地位,他们强调结构性动力机制的决定作用。然而后结构主义地理学者认为,尽管存在强大的结构力量,但是个体的能动作用也会改变地方性。目前尚未有研究成果明确地说明个体能动性与结构性动力之间的关系,而这正是该文的探索主题。以孔子故里曲阜为研究对象,采用经验主义的文献分析法,分析在曲阜地方性塑造过程中,结构性动力和非结构性动力的内容与关系及其背后的主体。结论如下:第一,在突破原有意识形态的意义上,孔子创立儒学体现了非结构的动力,这成为后续国库资金流向曲阜的动因。第二,历朝历代国家文化空间的建设目的是满足宣传国家正统意识形态需要,这是一种结构性的力量,它决定国家文化空间建设的财力分配去向。曲阜在尊孔兴儒的朝代里,获得国库拨付的大量资金,用以兴建大型建筑群等,这背后的主体是以帝王为首的官僚群体。第三,地方文化的形成和传承主要依靠地方居民。孔氏家族及其当地居民共同塑造了曲阜的地方文化,这是非结构力量的作用。这些非结构力量创造出来的地方性是吸引结构性动力下资金流动的源泉。若要曲阜文化价值在当今得到延续和提升,须调动国家与地方、政府与民间等多方面的积极性。 展开更多
关键词 地方性塑造 结构性动力 非结构性动力 曲阜
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The height-width ratio limited value for rubber bearing isolated structure computed by uniform design method 被引量:7
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作者 王铁英 王焕定 +1 位作者 张永山 刘文光 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第1期36-40,共5页
Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, wh... Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero. 展开更多
关键词 isolation structures the uniform design method regression analysis height-width ratio limited value
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Progressive collapse resisting capacity of reinforced concrete load bearing wall structures 被引量:1
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作者 Alireza Rahai Alireza Shahin Farzad Hatami 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2730-2738,共9页
Reinforced concrete(RC) load bearing wall is widely used in high-rise and mid-rise buildings. Due to the number of walls in plan and reduction in lateral force portion, this system is not only stronger against earthqu... Reinforced concrete(RC) load bearing wall is widely used in high-rise and mid-rise buildings. Due to the number of walls in plan and reduction in lateral force portion, this system is not only stronger against earthquakes, but also more economical. The effect of progressive collapse caused by removal of load bearing elements, in various positions in plan and stories of the RC load bearing wall system was evaluated by nonlinear dynamic and static analyses. For this purpose, three-dimensional model of 10-story structure was selected. The analysis results indicated stability, strength and stiffness of the RC load-bearing wall system against progressive collapse. It was observed that the most critical condition for removal of load bearing walls was the instantaneous removal of the surrounding walls located at the corners of the building where the sections of the load bearing elements were changed. In this case, the maximum vertical displacement was limited to 6.3 mm and the structure failed after applying the load of 10 times the axial load bored by removed elements. Comparison between the results of the nonlinear dynamic and static analyses demonstrated that the "load factor" parameter was a reasonable criterion to evaluate the progressive collapse potential of the structure. 展开更多
关键词 reinforced concrete(RC) load bearing wall structure progressive collapse fiber sections nonlinear analysis load factor method
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Nonlinear dynamic response analysis of supercavitating vehicles 被引量:1
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作者 麻震宇 林明东 +1 位作者 胡凡 张为华 《Journal of Central South University》 SCIE EI CAS 2012年第9期2502-2513,共12页
A finite element model for the supercavitating underwater vehicle was developed by employing 16-node shell elements of relative degrees of freedom.The nonlinear structural dynamic response was performed by introducing... A finite element model for the supercavitating underwater vehicle was developed by employing 16-node shell elements of relative degrees of freedom.The nonlinear structural dynamic response was performed by introducing the updated Lagrangian formulation.The numerical results indicate that there exists a critical thickness for the supercavitating plain shell for the considered velocity of the vehicle.The structure fails more easily because of instability with the thickness less than the critical value,while the structure maintains dynamic stability with the thickness greater than the critical value.As the velocity of the vehicle increases,the critical thickness for the plain shell increases accordingly.For the considered structural configuration,the critical thicknesses of plain shells are 5 and 7 mm for the velocities of 300 and 400 m/s,respectively.The structural stability is enhanced by using the stiffened configuration.With the shell configuration of nine ring stiffeners,the maximal displacement and von Mises stress of the supercavitating structure decrease by 25% and 17% for the velocity of 300 m/s,respectively.Compared with ring stiffeners,longitudinal stiffeners are more significant to improve structural dynamic performance and decrease the critical value of thickness of the shell for the supercavitating vehicle. 展开更多
关键词 supercavitating vehicle shell element of relative degrees of freedom nonlinear finite element dynamic response
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Exact Solutions of Nonlinear Dynamics Equation in a New Double—Chain Model of DNA 被引量:1
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作者 QIANXian-Min LOUSen-Yue 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第4期501-505,共5页
The exact solutions of the general nonlinear dynamic system in a new double-chain model of DNA are studied by using both the Conte's Painlevé truncation expansion and the Pickering's truncation expansion.... The exact solutions of the general nonlinear dynamic system in a new double-chain model of DNA are studied by using both the Conte's Painlevé truncation expansion and the Pickering's truncation expansion. The symmetric kink-kink shape excitations can be found in both the Conte's truncation expansion and the Pickering's truncation expansion. Three types of new localized excitations, the asymmetric kink-kink excitations, the soliton-kink excitation, and the kink-soliton excitations, are found by using the Pickering's nonstandard truncation expansion. 展开更多
关键词 double chain-model of DNA truncation expansion exact solution
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Dynamic analysis and nonlinear identification of space deployable structure 被引量:1
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作者 郭宏伟 刘荣强 邓宗全 《Journal of Central South University》 SCIE EI CAS 2013年第5期1204-1213,共10页
The dynamic equivalent continuum modeling method of the mast which is based on energy equivalency principle was investigated. And three kinds of mast dynamic model were established, which were equivalent continuum mod... The dynamic equivalent continuum modeling method of the mast which is based on energy equivalency principle was investigated. And three kinds of mast dynamic model were established, which were equivalent continuum model, finite element model and simulation model, respectively. The mast frequencies and mode shapes were calculated by these models and compared with each other. The error between the equivalent continuum model and the finite element model is less than 5% when the mast length is longer. Dynamic responses of the mast with different lengths are tested, the mode frequencies and mode shapes are compared with finite element model. The mode shapes match well with each other, while the frequencies tested by experiments are lower than the results of the finite element model, which reflects the joints lower the mast stiffness. The nonlinear dynamic characteristics are presented in the dynamic responses of the mast under different excitation force levels. The joint nonlinearities in the deployable mast are identified as nonlinear hysteresis contributed by the coulomb friction which soften the mast stiffness and lower the mast frequencies. 展开更多
关键词 deployable structure finite element model equivalent continuum model NONLINEAR dynamic analysis
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Theoretical Study on Effects of Salt and Temperature on Denaturation Transition of Double-stranded DNA
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作者 DONGRui-Xin YANXun-Ling +2 位作者 PANGXiao-Feng JIANGShan LIUSheng-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第3期465-469,共5页
We investigate the statistical mechanics properties of a nonlinear dynamics model of the denaturation of the DNA double-helix and study the effects of salt concentration and temperature on denaturation transition of D... We investigate the statistical mechanics properties of a nonlinear dynamics model of the denaturation of the DNA double-helix and study the effects of salt concentration and temperature on denaturation transition of DNA. The specific heat, entropy, and denaturation temperature of the system versus salt concentration are obtained. These results show that the denaturation of DNA not only depends on the temperature but also is influenced by the salt concentration in the solution of DNA, which are in agreement with experimental measurement. 展开更多
关键词 DNA DENATURATION salt concentration
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Bifurcation control and eigenstructure assignment in continuous solution polymerization of vinyl acetate 被引量:1
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作者 张楠 邱彤 陈丙珍 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第9期1523-1529,共7页
The major difficulty in achieving good performance of industrial polymerization reactors lies in the lack of understanding of their nonlinear dynamics and the lack of well-developed techniques for the control of nonli... The major difficulty in achieving good performance of industrial polymerization reactors lies in the lack of understanding of their nonlinear dynamics and the lack of well-developed techniques for the control of nonlinear processes, which are usually accompanied with bifurcation phenomenon. This work aims at investigating the nonlinear behavior of the parameterized nonlinear system of vinyl acetate polymerization and further modifying the bifurcation characteristics of this process via a washout filter-aid controller, with all the original steady state equilibria preserved. Advantages and possible extensions of the proposed methodology are discussed to provide scientific guide for further controller design and operation improvement. 展开更多
关键词 Vinyl acetate polymerization Nonlinear dynamics Bifurcation control Eigenvalue assignment Washout filters
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Progressive Collapse Analysis of Concrete-Filled Steel Tubular Frames with Semi-rigid Connections
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作者 徐嫚 张素梅 +1 位作者 郭兰慧 王玉银 《Transactions of Tianjin University》 EI CAS 2011年第6期461-468,共8页
A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of sim... A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of simulation, which include substructure model, beam element model and solid element model. The comparison results show that the substructure model has a satisfying capability, calculation efficiency and accuracy to predict the concerned joints as well as the overall framework. Based on the substructure model and a kind of semi-rigid connection for concretefilled square hollow section steel column proposed in this paper, the nonlinear dynamic analyses are conducted by the alternate path method. It is found that the removal of the ground inner column brings high-level joint moments and comparatively low-level axial tension forces. The initial stiffness and transmitted ultimate moment of the semi-rigid connection are the main factors that influence the frame behavior, and their lower limit should be guaranteed to resist collapse. Reduced ultimate moment results in drastic displacement and axial force development, which may bring progressive collapse. The higher initial stiffness ensures that the structure has a stronger capacity to resist progressive collapse. 展开更多
关键词 substructure model concrete-filled steel tubular frame semi-rigid connection alternate path method dynamic analysis
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基于行动者网络和共享经济视角的乡村民宿发展及空间重构——以深圳官湖村为例 被引量:90
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作者 陈燕纯 杨忍 王敏 《地理科学进展》 CSSCI CSCD 北大核心 2018年第5期718-730,共13页
立足于乡村空间多元分化研究的学术背景,采用深度访谈法,结合行动者网络分析框架,对深圳市官湖村民宿集群旅游空间发展的过程和空间重构效应进行分析。结果表明:(1)民宿业主和熟人网络是官湖村民宿旅游发展的核心行动者,在其主导推动下... 立足于乡村空间多元分化研究的学术背景,采用深度访谈法,结合行动者网络分析框架,对深圳市官湖村民宿集群旅游空间发展的过程和空间重构效应进行分析。结果表明:(1)民宿业主和熟人网络是官湖村民宿旅游发展的核心行动者,在其主导推动下实现了乡村物质景观空间和社会空间的转型和重构。(2)官湖村的空间重构过程中,民宿旅游的行动者网络空间随着熟人网络的不断建构和转译而促成越来越多分散的人力资本、经济资本和社会资本集中并转化为官湖村发展的社会资源。民宿业主和熟人网络共同构成了官湖村发展的非结构性动力主体。(3)外来行动者构建的新型社会熟人网络,与官湖村传统社会熟人网络因无法完成转译过程和连通,造成官湖村民宿业主等群体和当地村民等群体的社会分化隔离与关系网络的权力斗争,进而引起动力机制从非结构性向二元动力机制转变,带来新的物质空间重构。(4)在共享经济演进过程中,官湖村形成一种基于社会熟人关系网络,线下为主并与线上相结合的商品共享和服务交易的新型共享经济模式,是一种比互联网中介更加低成本的共享方式。 展开更多
关键词 民宿发展 共享经济 行动者网络 熟人网络 社会空间 非结构性动力
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Abnormality diagnosis of cracks in the concrete dam based on dynamical structure mutation 被引量:18
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作者 GU ChongShi LI ZhanChao XU Bo 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第7期1930-1939,共10页
A method of the fuzzy cross-correlation factor exponent in dynamics is researched and proposed to diagnose abnormality of cracks in the concrete dam. Moreover, the Logistic time series changing from period-doubling bi... A method of the fuzzy cross-correlation factor exponent in dynamics is researched and proposed to diagnose abnormality of cracks in the concrete dam. Moreover, the Logistic time series changing from period-doubling bifurcation to chaos is tested first using this method. Results indicate that it can distinguish inherent dynamics of time series and can detect mutations. Considering that cracks in the concrete dam constitute an open, dissipative and complex nonlinear dynamical system, a typical crack on the downstream face of a concrete gravity arch dam is analyzed with the proposed method. Two distinct mutations are discovered to indicate that the abnormality diagnosis of cracks in the concrete dam is achieved dynamically through this method. Furthermore, because it can be directly utilized in the measured crack opening displacement series to complete abnormality diagnosis, it has a good prospect for practical applications. 展开更多
关键词 dynamical structure mutation cracks in the concrete dam method of the fuzzy cross-correlation factor exponent indynamics abnormality diagnosis of cracks
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An efficient time-integration method for nonlinear dynamic analysis of solids and structures 被引量:2
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作者 LIU TianYun LI QingBin ZHAO ChongBin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第4期798-804,共7页
This paper presents an efficient time-integration method for obtaining reliable solutions to the second-order nonlinear dynamic problems in structural engineering. This method employs both the backward-acceleration di... This paper presents an efficient time-integration method for obtaining reliable solutions to the second-order nonlinear dynamic problems in structural engineering. This method employs both the backward-acceleration differentiation formula and the trapezoidal rule, resulting in a self-starting, single step, second-order accurate algorithm. With the same computational effort as the trapezoidal rule, the proposed method remains stable in large deformation and long time range solutions even when the trapezoidal rule fails. Meanwhile, the proposed method has the following characteristics: (1) it is applicable to linear as well as general nonlinear analyses; (2) it does not involve additional variables (e.g. Lagrange multipliers) and artificial parameters; (3) it is a single-solver algorithm at the discrete time points with symmetric effective stiffness matrix and effective load vectors; and (4) it is easy to implement in an existing computational software. Some numerical results indicate that the proposed method is a powerful tool with some notable features for practical nonlinear dynamic analyses. 展开更多
关键词 two-order system conservation of energy backward differentiation formula Newmark method nonlinear dynamics unconditional stability direct time integration
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Global dynamics of a heroin epidemic model with age structure and nonlinear incidence 被引量:3
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作者 Junyuan Yang Xiaoxia Li Fengqin Zhang 《International Journal of Biomathematics》 2016年第3期1-20,共20页
A heroin model with nonlinear incidence rate and age structure is investigated. The basic reproduction number is determined whether or not a heroin epidemic breaks out. By employing the Lyapunov functionals, the drug-... A heroin model with nonlinear incidence rate and age structure is investigated. The basic reproduction number is determined whether or not a heroin epidemic breaks out. By employing the Lyapunov functionals, the drug-free equilibrium is globally asymptotically stable if R0 ≤1; while the drug spread equilibrium is also globally asymptotically stable if R0≤ 1. Our results imply that improving detected rates and drawing up the efficient prevention play more important role than increasing the treatment for drug users. 展开更多
关键词 Nonlinear incidence EQUILIBRIA global stability.
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