农村声望地位的阶层确认研究——基于“结构——互动”视角的解读

基于东部农村的实地调查发现,阶层分化背景下富人阶层凭借经济地位实现了对声望地位的确认,亦即声望地位与经济地位之间存在选择性亲和。声望地位阶层确认的实践机制为富人借助于经济资源以私促公以及以私助私,具体而言公的层面包括富人阶层为其他阶层提供生存型与发展型公共品,私的层面包括富人对其他阶层的日常性的礼物赠予与扶危济困,由此形成了其他阶层对富人资源的依赖。人际交往的互惠原则,即施报平衡,在富人阶层无需其他阶层以有形资源回馈背景下推动了其他阶层让渡对富人阶层的服从与尊敬,以此富人阶层获得较高声望。上层富人对声望地位的阶层确认实践离不开社会结构支撑,高度熟悉与信息对称的熟人社会为富人阶层获得声望地位提供空间基础,地方性规范的软约制保障了富人阶层对其他阶层自愿让渡尊敬与信任,以及村庄的归属与价值共同体意涵构成了富人追求声望地位的动力。上层富人对声望地位的阶层确认实践重塑着社会结构,体现在村民间熟悉与信任度下降以及村落共同体意涵弱化,熟人社会走向半熟人化。

Eco-spatial Structure of Urban Agglomeration

In terms of ecological theory, this paper makes a comprehensive analysis of the mutualism and co- evolutionary mechanism between the eco-spatial structure and socio-economic development of the urban agglomeration, and maps out optimized modes of the eco-spatial structure of the urban agglomeration. The analysis is a case study of the urban agglomeration on different levels of global, national, provincial and local scales, on the basis of those conclusions are drawn: 1) Within the scope of the urban agglomeration, the cities should be reasonably sized and appropriately densified; the spatial combination of the urban agglomeration ought to be orderly, and its eco-spatial structure ought to be optimized and efficient; the relationship between the economic society and eco-spatial environment ought to be that of mutual benefit and co-evolution. 2) “The mode of corridor group network” is a certain trend evoked from the spatial structure of urban agglomeration. 3) The eco-spatial structure of urban agglomeration under “the mode of corridor group network” can further increase the environmental capacity of urban agglomeration, and is in favor of the harmonious relationship between man and nature.

Dynamic Interaction of Soil-Isolated Structure:A Systematic Review

Isolation technique of ground structure is a hot topic in the field of earthquake engineering and structure dynamics.Since soil-isolated structure dynamic interaction study is of great significance to enhance seismic performance of isolated structures and revision of relevant isolation specifications,research on dynamic interaction of soil-isolated structure has attracted more and more attention.Based on the basic theory of soil-structure dynamic interaction,we summarize and analyze the research status quo of soil-isolated structure dynamic interaction by means of theoretical analysis,numerical simulation,model test,prototype observation and seismic performance.After reviewing the results of previous research,we reveal that some key issues,which can be used to uncover dynamic interaction mechanism and seismic response characteristics of soil-isolated structures interaction system,should not be neglected.Based on the concept of seismic performance design and the latest research of soil-isolated structure dynamic interaction,we predict the future development of soil-isolated structure dynamic interaction by elastoplastic time history analysis method,seismic performance level and practical analysis method based on energy.

A CFD Based Investigation of the Unsteady Hydrodynamic Coefficients of 3-D Fins in Viscous Flow

The motion of the fins and control surfaces of underwater vehicles in a fluid is an interesting and challenging research subject.Typically the effect of fin oscillations on the fluid flow around such a body is highly unsteady, generating vortices and requiring detailed analysis of fluid-structure interactions.An understanding of the complexities of such flows is of interest to engineers developing vehicles capable of high dynamic performance in their propulsion and maneuvering.In the present study, a CFD based RANS simulation of a 3-D fin body moving in a viscous fluid was developed.It investigated hydrodynamic performance by evaluating the hydrodynamic coefficients (lift, drag and moment) at two different oscillating frequencies.A parametric analysis of the factors that affect the hydrodynamic performance of the fin body was done, along with a comparison of results from experiments.The results of the simulation were found in close agreement with experimental results and this validated the simulation as an effective tool for evaluation of the unsteady hydrodynamic coefficients of 3-D fins.This work can be further be used for analysis of the stability and maneuverability of fin actuated underwater vehicles.

Theoretical Study of Hydration Effects on the Selectivity of 18-Crown-6 Between K~＋ and Na~＋

A combination of molecular dynamics （MD） and density functional theory （DFT） calculations were used to study the hydration structures of K＋ and Na＋ ions under the confinement of 18-crown-6 in order to identify the role of water in the selectivity of 18-crown-6 towards K＋.The radial distribution functions,coordination num-bers,orientation structures and interaction energies were analyzed to investigate the hydration of K＋ and Na＋ in 18-crown-6/cation complexes.All calculations of K＋ and Na＋ in bulk water were also conducted for comparison.The simulation results show that the orientation distributions of the water molecules in the first coordination shell of K＋ are more sensitive to the confinement of 18-crown-6 than those of Na＋.It is more favorable to confine a K＋ in 18-crown-6 than a Na＋ in terms of interaction energy.Good agreement is obtained between MD results and DFT results.

Interaction Between Large-scale Vortex Structure and Dispersed Particles in a Three Dimensional Mixing Layer

In order to understand the interaction between large-scale vortex structure and particles, a two-way coupling temporal mixing layer laden with particles at a Stokes number of 5 with different mass loading planted initially in the upper half region is numerically studied. The pseudospectral method is used for the flow fluid and the Lagrangian approach is employed to trace particles. The momentum coupling effect introduced by a particle is approximated to a point force. The simulation results show that the coherent structures are still dominant in the mixing layer, but the large-scale vortex structure and particle dispersion are modulated. The length of large-scale vortex structure is shortened and the pairing is delayed. At the same time, the particles are distributed more evenly in the whole flow field as the mass loading is increased, but the particle dispersion along the transverse direction differs from that along the spanwise direction, which indicates that the effect by the addition of particle on the spanwise large-scale vortex structure is different from the streamwise counterpart.

DYNAMIC FINITE LAYER-ELEMENT ANALYSIS OF SOIL-STRUOTURE INTERACTION FOR NEW-TYPE OFFSHORE PLATFORM

In this paper, a new method called dynamic finite layer--element method (DFLEM) is used to analyse the soil--structure interaction of new type offshore platforms. Some valuable results have been obtained. The results show that the DFLEM is a new effective method to analyse dynamic soil--structure interaction and can be applied widely in practice.

Vibration Analysis of Frame Structure with Soil-Structure Interaction

A common design practice for dynamic loading assumes the frame fixed at their bases. In reality, the supporting soil medium allows movement to some extent due to its property to deform. This may decrease the overall stiffness of the structural system and may increase the natural period of the system. The effect of soil flexibility is suggested to be accounted through consideration of springs which have specified stiffness and soil half space. Results show that the dynamic response of frame structure to vibrations is due to applied dynamic load and is highly dependent on the soil type and the method of modeling soil structure interaction. The response of frame structure under dynamic load is higher in case of linear discrete independent spring as comparing with perfect bond cases. Except the response of frame in case of piles embedded in soft clay, half space are higher than frame with piles and linear elastic spring due to the interaction between the frequencies of applied load and frequencies of frame structure. Also, result showed that it is important to include the soil-structure interaction in the analysis of the system in order to correctly simulate the dynamic problem for controlling on the resonance phenomena.

Dominance hierarchy and social relationships in a group of Captive black-and-white snub-nosed monkeys (Rhinopithecus bietl)

Different types of dominance hierarchies reflect different social relationships in primates. In this study, we clarified the hierarchy and social relationships in a one-male unit of captive Rhinopithecus bieti observed between August 1998 and March 1999. Mean frequency of agonistic behaviour among adult females was 0.13 interactions per hour. Adult females exhibited a linear hierarchy with a reversal of 10.9%, indicating an unstable relationship; therefore, R. bieti appears to be a relaxed/tolerant species. The lack of a relationship between the agonistic ratio of the adult male towards adult females and their ranks indicated that males did not show increased aggression towards low-ranking females. Differentiated female affiliative relationships were loosely formed in terms of the male, and to some extent influenced by female estrus, implying that relationships between the male and females is influenced by estrus and not rank alone. A positive correlation between the agonistic ratio of adult females and their ranks showed that the degree to which one female negatively impacted others decreased with reduction in rank. Similarly, a positive correlation between the agonistic ratio of females and differences in rank suggests that a female had fewer negative effects on closely ranked individuals than distantly ranked ones. These data indicate that rank may influence relationships between females. A steeper slope of regression between the agonistic ratio and inter-female rank differences indicated that the extent of the power difference in high-ranking females exerting negative effects on low-ranking ones was larger during the mating season than the birth season, suggesting that rank may influence the mating success of females.

基层治理中的问责乱象如何精准纠治?——基于“结构—行动”互动视角的考察

问责制是国家治理体系中的一项重要制度设计,一旦问责制失灵对治理体系的危害是巨大的。聚焦基层问责乱象,以吉登斯的结构化理论为基础,可以建构“结构—行动”互动的分析框架,提出问责行为受到问责体系的内在行动者因素和外在结构性条件的双重约束,问责乱象的生成与结构层面的责任化倾向和行动层面的认知偏差有关。并据此,将问责乱象划分为情绪式问责、运动式问责、加码式问责和机械式问责等四类具有代表性的情境。相较于控制路径的问责,信任路径的问责更匹配建立在人民信任关系基础上的治理体系。围绕问责的四种异化形态,能够有针对性地提出认知治理、规范治理、精细治理、期望治理等四条差别化的纠治路径,以期问责行动能够回归最本质需求,维护良好政治秩序。

Elastodynamic Infinite Elements with Modified Bessel Shape Functions for Dynamic Soil-Structure Interaction

The paper is devoted to formulations of decay and mapped elastodynamic infinite elements, based on modified Bessel shape functions. These elements are appropriate for Soil-Structure Interaction （SSI） problems, solved in time or frequency domain and can be treated as a new form of the recently proposed Elastodynamic Infinite Elements with United Shape Functions （EIEUSF） infinite elements. The formulation of 2D Horizontal type Infinite Elements （HIE） is demonstrated here, but by similar techniques 2D Vertical （VIE） and 2D Comer （CIE） Infinite Elements can also be formulated. Using elastodynamic infinite elements is the easier and appropriate way to achieve an adequate simulation including basic aspects of Soil-Structure Interaction. Continuity along the artificial boundary （the line between finite and infinite elements） is discussed as well and the application of the proposed elastodynamic infinite elements in the Finite Element Method （FEM） is explained in brief. Finally, a numerical example shows the computational efficiency of the proposed infinite elements.

Changes in Coupled Vibration Frequencies and Modes of Wall-Cavity Systems Induced by Stiffness Variation in the Structure

Problems of fluid structure interactions are governed by a set of fundamental parameters. This work aims at showing through simple examples the changes in natural vibration frequencies and mode shapes for wall-cavity systems when the structural rigidity is modified. Numerical results are constructed using ANSYS software with triangular finite elements for both the fluid （2D acoustic elements） and the solid （plane stress） domains. These former results are compared to proposed analytical expressions, showing an alternative benchmark tool for the analyst. Very rigid wall structures imply in frequencies and mode shapes almost identical to those achieved for an acoustic cavity with Neumann boundary condition at the interface. In this case, the wall behaves as rigid and fluid-structure system mode shapes are similar to those achieved for the uncoupled reservoir case.

Hydroelastic Analysis of a Very Large Floating Structure Edged with a Pair of Submerged Horizontal Plates

This paper is concerned with the hydroelastic problem of a very large pontoon-type floating structure(VLFS) edged with a pair of submerged horizontal plates, which is a combination of perforated and non-perforated plates attached to the for-end and back-end of the VLFS. For the hydroelastic analysis, the fluid is assumed to be ideal and its motion is irrotational so that a velocity potential exists. The VLFS is modeled as an elastic plate according to the classical thin plate theory. The fluid-structure interaction problem is separated into conventional hydrodynamics and structure dynamics by using modal expansion method in the frequency-domain. It involves, firstly, the deflection of the VLFS, which is expressed by a superposition of modal functions and corresponding modal amplitudes. Then the boundary element method is used to solve the integral equations of diffraction and radiation on the body surface for the velocity potential, whereas the vibration equation is solved by the Galerkin's method for modal amplitudes, and then the deflection is obtained by the sum of multiplying modal functions with modal amplitudes. This study examines the effects of the width and location of the non-perforated horizontal plates on the hydroelastic response of the VLFS, then the performance of perforated plates is investigated to reduce the motion near the fore-end of the VLFS. Considering the advantages and disadvantages of submerged plates without and with cylindrical holes, we propose a simple anti-motion device, which is a combination of a pair of perforated and non-perforated plates attached to the for-end and back-end of the VLFS. The effectiveness of this device in reducing the deformation and bending moment of the VLFS has been confirmed, and is compared with the results in cases without and with the submerged horizontal plates by the analysis in this paper.

Relative Contributions of Spatial and Environmental Processes and Biotic Interactions in a Soil Collembolan Community

Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communities on a small scale. To evaluate the relative roles of biotic interactions and environmental and spatial processes in a soil collembolan community, a field experiment was carried out on a small scale(50 m) in the farmland ecosystem of the Sanjiang Plain, Northeast China. In August and October, 2011, we took 100 samples each month in a 50 m × 50 m plot using a spatially delimited sampling design. Variation partitioning was used to quantify the relative contributions of the spatial and environmental variables. A null model was selected to test for the non-randomness pattern of species co-occurrence and body size in assemblages of collembolans and to test whether the pattern observed was the result of environmental or biotic processes that structured the community on a small scale. The results showed that large variance was accounted for by spatial variables(18.99% in August and 21.83% in October, both were significant). There were relatively lower effects of environmental variation(3.56% in August and 1.45% in October, neither was significant), while the soil water content, soil p H and soybean height explained a significant portion of the variance that was observed in the spatial pattern of the collembolan community. Furthermore, the null model revealed more co-occurrence than expected by chance, suggesting that collembolan communities had a non-random co-occurrence pattern in both August and October. Additionally, environmental niche overlap and the body size ratio of co-occurrence showed that interspecific competition was not influential in collembolan community structuring. Considering all of the results together, the contributions of spatial and environmental processes were stronger than biotic interactions in the small-scale structuring of a soil collembolan community.

Using FEM to predict tree motion in a wind field

In this paper we propose a finite element(FE) simulation method to predict tree motion in a wind field. Two FE tree models were investigated:One model was generated based on a realistic nature-looking geometric tree model,and the other was a symmetric model to investigate the influence of asymmetric material properties on tree motion. The vortex-induced vibration(VIV) theory is introduced to estimate the fluctuating wind force being exerted on tree stems and the fluid-structure interaction(FSI) analysis is also included in the simulation. The results indicate that asymmetric material properties result in the crosswind displacement of the investigated node and the main swaying direction deviation. The simulation reveals that under wind loading,a tree with leaves has much larger swaying amplitude along the wind direction and longer swaying period than a tree without leaves. However,the crosswind swaying amplitude is mainly due to branch interaction. The numerical simulation proved that the inter-action of tree branches can prevent dangerous swaying motion developing.

Progressive failure processes of reinforced slopes based on general particle dynamic method

In order to resolve grid distortions in finite element method(FEM), the meshless numerical method which is called general particle dynamics(GPD) was presented to simulate the large deformation and failure of geomaterials. The Mohr-Coulomb strength criterion was implemented into the code to describe the elasto-brittle behaviours of geomaterials while the solid-structure(reinforcing pile) interaction was simulated as an elasto-brittle material. The Weibull statistical approach was applied to describing the heterogeneity of geomaterials. As an application of general particle dynamics to slopes, the interaction between the slopes and the reinforcing pile was modelled. The contact between the geomaterials and the reinforcing pile was modelled by using the coupling condition associated with a Lennard-Jones repulsive force. The safety factor, corresponding to the minimum shear strength reduction factor "R", was obtained, and the slip surface of the slope was determined. The numerical results are in good agreement with those obtained from limit equilibrium method and finite element method. It indicates that the proposed geomaterial-structure interaction algorithm works well in the GPD framework.

Seismic Response of a Structure under Various Subsoi Models

Three types of the soil-structure interaction are used for structure analysis loaded by seismic effects. An example of the real RC building is used to demonstrate differences in the dynamic response results in the calculation of internal forces and displacements. Variant three options of the soil models were used as a building supporting structure. In the case of soil model A, the soil was modelled by using of equivalent stiffness values, stemming from the theory of a rigid circular disc on an elastic homogeneous half-space. Non-uniformly modelled vertical stiffness of the soil according to the Boussinesq model was used for model B. Both models A and B are characterised by the ＂averaged＂ soil model on the bases of spring constants. Model C was used for the soil better corresponding to its actual composition by the Winkler-Pasternak theory. Model C, where the actual layered soil is considered, is modelled more accurately than for the ＂averaged＂ soil of models A and B. The dynamic response of models operating with ＂averaged＂ values of rigid and soft soil layers is markedly shifted to the conservative smaller values of internal forces. The building response tbr model C in dynamic displacements is significantly higher than for the both models A and B.

Coupling simulation of fluid structure interaction in the stirred vessel with a pitched blade turbine

The interaction between fluid and a down-pumping pitched blade turbine fixed with a flexible shaft in the stirred vessel, as a typical fluid structure interaction phenomenon, was simulated by coupling the Computational Fluid Dynamics and Computational Structural Dynamics. Based on the verification of the simulated impeller torque and dimensionless shaft bending moment with experimental result, the dimensionless shaft bending moment and various loads acting on impeller(including lateral force, axial force and bending moment) were discussed in detail. By separating and extracting the fluid and structural components from those loads, the results show that the shaft bending moment mainly results from the lateral force on impeller although the axial force on impeller is much larger. The impeller mass imbalance increases the shaft bending moment and the lateral force on impeller, but has little influence on the axial force and bending moment acting on impeller. The dominant frequencies of impeller forces are macro-frequency, speed frequency and blade passing frequency, and are associated with the impeller mass imbalance.

Aeroelastic Simulation for Symmetric Manoeuvre of 123 Manager Light Plane

Expansion of computer technologies allow using numerical simulation in the early stages of aircraft design more and more often. The role of both wind tunnels and initial test flights used to verify the validity of solutions seems to be diminishing. Big systems for three-dimensional simulations of Fluid-Structure Interactions （FSI） constitute highly specialized and costly software. Most of the codes are based on many simplifications. In this paper fluid-structure interaction, taking into account the symetric manoeuvre of ultra light plane, is concerned. This phenomenon has important influence in many aeronautical applications. The method and developed system is demonstrated on ultra light I23 plane. For the first flow the comparison with experiment made in Institute of Aviation Warsaw is presented. Finally, aeroelastic simulation of full 123 aircraft configuration presents the capability of used numerical codes to analyze largescale complex geometries for manoeuvre. All computations were carried out in parallel environment for CFD mesh of order of millions tetrahedral elements.

A Numerical Modeling of the Vortex-induced Vibration of Cascade in Turbomachinery using Immersed Boundary Method

Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate system.The numerical method is applied to the simulation of the flow passing an oscillating circular cylinder which is forced to move in X direction under prescribed motions in water at rest at low Keulegan-Carpenter numbers.Then vor-tex-induced vibration of a cylinder with two degrees of freedom which oscillates in in-line direction and transverse direction is simulated using this method.The results are in good agreement with the previous research.Then the method is extended to the oscillating cascade simulation of making various comparisons.It is found that the IBPA(inter blade phase angle) will change as the time goes on,because of the non-uniformity of the flow in the circumferential direction,until the oscillating cascade goes to a stable situation.The reduced velocity and the number of blades are chosen to investigate the effects of them on IBPA.The results indicate that both the reduced velocity and the number of blades are the main factors which influence IBPA.It is worth noting that the coupling process is not necessary to generate any body-fitting grids,which makes it much faster in computational process for such a complicated fluid-structure interaction problem.