Nonequilibrium Thermodynamic and Dissipative Structure Mechanism of Fluidized Beds

Fluidized beds are nonlinear dynamic systems that exchange mass and energy with outside. They are governed not only byfluid dynamics, but by thermodynamics, especially the second law of thermodynamics as well. According to Prigogine's dissipative structure theory, the following have been concluded: (l) a fixed bed is on thermodynamic blanch, and bubbling, turbulent and fast beds areon the dissipatve structure branches. (2) Entropy in fluidized beds is divided into tWo parts: entropy production and entropy flux. The latter increases with gas velocity and decreases with pressure of the systems. That means the entropy of a system may reduce and the systemwith higher gas velocity behaves as dissipative structure characteristics. (3) For a giVen velocity, a fluidized bed operates stably on thewhole, but it is unstable to local gas-solid phases. The unstable phases are described by fluid dynamic equations, While the minimum ofsystem energy function assures whole stability of the system. (4) A transition criterion of a bubbling bed is derived from Prigogine's stability theory.

NONLINEAR EVOLUTION SYSTEMS AND GREEN’S FUNCTION

In this paper, we will introduce how to apply Green＇s function method to get the pointwise estimates for the solutions of Cauchy problem of nonlinear evolution equations with dissipative structure. First of all, we introduce the pointwise estimates of the time-asymptotic shape of the solutions of the isentropic Navier-Stokes equations and show to exhibit the generalized Huygen＇s principle. Then, for other nonlinear dissipative evolution equations, we will only introduce the result and give some brief explanations. Our approach is based on the detailed analysis of the Green＇s function of the linearized system and micro-local analysis, such as frequency decomposition and so on.

Study on Wave Dissipation of the Structure Combined by Baffle and Submerged Breakwater

This paper proposes a structure combined by baffle and submerged breakwater （abbreviated to SCBSB in the following texts）. Such a combined structure is conducive to the water exchange in the harbor, and has strong capability on wave dissipation. Our paper focuses on the discussion of two typical structures, i.e., the submerged baffle and rectangular breakwater combined with the upper baffle respectively, which are named as SCBSB 1 and SCBSB2 for short. The eigenfunction method corrected by experimental results is used to investigate the wave dissipation characteristics. It shows that the calculated results agree well with the experimental data and the minimum value of the wave transmission coefficient can be obtained when the distance between the front and rear structures is from 1/4 to 1/2 of the incident wave length.

Characteristics of viscous debris flow in a drainage channel with an energy dissipation structure

A new type of drainage channel with an energy dissipation structure has been proposed based on previous engineering experiences and practical requirements for hazard mitigation in earthquakeaffected areas.Experimental studies were performed to determine the characteristics of viscous debris flow in a drainage channel of this type with a slope of 15%.The velocity and depth of the viscous debris flow were measured,processed,and subsequently used to characterize the viscous debris flow in the drainage channel.Observations of this experiment showed that the surface of the viscous debris flow in a smooth drainage channel was smoother than that of a similar debris flow passing through the energy dissipation section in a channel of the new type studied here.However,the flow patterns in the two types of channels were similar at other points.These experimental results show that the depth of the viscous debris flow downstream of the energy dissipation structure increased gradually with the length of the energy dissipation structure.In addition,in the smooth channel,the viscous debris-flow velocity downstream of the energy dissipation structure decreased gradually with the length of the energy dissipation structure.Furthermore,theviscous debris-flow depth and velocity were slightly affected by variations in the width of the energy dissipation structure when the channel slope was 15%.Finally,the energy dissipation ratio increased gradually as the length and width of the energy dissipation structure increased;the maximum energy dissipation ratio observed was 62.9%(where B = 0.6m and L/w = 6.0).

Hydraulic Design Method of Wave Dissipating Structure with Partially Perforated Front Wall

Based on the matching conditions of different fluid regions, the eigenfunction expansion method is used to develop a theoretical formula for wave reflection in front of the perforated structure with a partially slit front wall. The accuracy of the solution is verified by comparing the numerical results with experimental data. In addition, a new hydraulic design method is developed by derivation of the theoretical formula with respect to the porosity of the slit wall, and the results of this design method is drafted for harbour engineers to use.

A spatially triggered dissipative resource distribution policy for SMT processors

Programs take on changing behavior at nmtime in a simultaneous multithreading （SMT） environment. How reasonably common resources are distributed among the threads significantly determines the throughput and fairness performance in SMT processors. Existing resource distribution methods either mainly rely on the front-end fetch policy, or make distribution decisions according to the limited information from the pipeline. It is difficult for them to efficiently catch the various resource requirements of the threads. This work presents a spatially triggered dissipative resource distribution （SDRD） policy for SMT processors, its two parts, the self-organization mechanism that is driven by the real-time instructions per cycle （IPC） performance and the introduction of chaos that tries to control the diversity Of trial resource distributions, work together to supply sustaining resource distribution optimization for changing program behavior. Simulation results show that SDRD with fine-grained diversity controlling is more effective than that with a coarse-grained one. And SDRD benefits much from its two well-coordinated parts, providing potential fairness gains as well as good throughput gains. Meanings and settings of important SDRD parameters are also discussed.

Ore Zoning as Self-Organization of Geochemical Dynamic Systems

Zoning in ore bodies, ore deposits and ore regions are recognized as temporal-spatial structures generated by the dynamics of ore- forming processes. Viewed from the theory of dissipative structures, ore zoning is a kind of self-organization phenomenon occurring in far from-equilibrium geochemical dynamic systems. Therefore,kinetic and dynamic approaches must be taken to reveal the mechanisms of ore zoning. Two dominant coupling processes leading to ore zoning——reaction-transport feedbacks and double-diffusive convection——are discussed.

Discussion of Dissipation Structure in a Directionally Solidified Alloy

The dissipation theory was introduced into the solidification area to describe the inherent laws of solidification from a new viewpoint. Discussion demonstrates that the solid / liquid interface in a directionally solidified alloy belongs to a kind of dissipation structure

基于耗散结构理论的公立医院组织韧性形成机制研究

借助耗散结构理论探寻公立医院组织韧性的形成机制和培育策略。首先分析耗散结构理论与公立医院组织韧性的关联性;其次从识别危机信号、适应危机变化、实现危机中反弹3个阶段分析公立医院组织韧性的形成路径,聚焦于检测性激活、适应性重构、反思性转化3项动态循环的行为,并结合耗散结构理论中熵变调节、自组织机制、涨落反馈等核心思想,提取组织韧性形成的6个关键要素,即预防正熵、增加负熵、制度适时调整、资源调配使用、反思学习、组织优化,并对每个关键要素对应的行为表现进行阐述;再者提出公立医院组织韧性的培育策略,包括培育公立医院物理韧性、制度韧性、人员技术韧性、心理韧性等,以期实现公立医院由脆弱性向韧性转变。

Dissipative structure for symmetric hyperbolic systems with memory

We study symmetric hyperbolic systems with memory-type dissipation and investigate their dissipative structures.We treat two cases:memory-type diffusion and memory-type relaxation,and observe that the dissipative structures of these two cases are essentially different.Namely,we show that the dissipative structure of the system with memory-type diffusion is of the standard type,while that of the system with memory-type relaxation is of the regularity-loss type.

Symplectic(辛)几何学与航空发动机的结构设计

Ｓｙｍｐｌｅｃｔｉｃ（辛）几何学与航空发动机的结构设计西北工业大学教授邓子辰计算结构力学与最优控制模拟理论的建立，说明这两门学科之间存在相似性。近几年的工作主要是将结构力学中的一些有效方法（如多重子结构法、能量法等）成功地引入了最优控制领域，并已取...

Antitumor effects of electrochemical treatment

Electrochemical treatment is an alternative modality for tumor treatment based on the application of a low intensity direct electric current to the tumor tissue through two or more platinum electrodes placed within the tumor zone or in the surrounding areas. This treatment is noted for its great effectiveness, minimal invasiveness and local effect. Several studies have been conducted worldwide to evaluate the anfitumoral effect of this therapy. In all these studies a variety of biochemical and physiological responses of tumors to the applied treatment have been obtained. By this reason, researchers have suggested various mechanisms to explain how direct electric current destroys tumor ceils. Although, it is generally accepted this treatment induces electrolysis, electroosmosis and electroporation in tumoral tissues. However, action mechanism of this alternative modality on the tumor tissue is not well understood. Although the principle of Electrochemical treatment is simple, a standardized method is not yet available. The mechanism by which Electrochemical treatment affects tumor growth and survival may represent more complex process. The present work analyzes the latest and most important research done on the electrochemical treatment of tumors. We conclude with our point of view about the destruction mechanism features of this alternative therapy. Also, we suggest some mechanisms and strategies from the thermodynamic point of view for this therapy. In the area of Electrochemical treatment of cancer this tool has been exploited very little and much work remains to be done. Electrochemical treatment constitutes a good therapeutic option for patients that have failed the conventional oncology methods.

Study on the stability of switched dissipative Hamiltonian systems

The hybrid Hamiltonian system is a kind of important nonlinear hybrid systems. Such a system not only plays an important role in the development of hybrid control theory, but also finds many applications in practical control designs for obtaining better control performances. This paper investigates the stability of switched dissipative Hamiltonian systems under arbitrary switching paths. Under a realistic assumption, it is shown that the Hamiltonian functions of all the subsystems can be used as the multiple-Lyapunov functions for the switched dissipative Hamiltonian system. Based on this and using the dissipative Hamiltonian structural properties, this paper then proves that the P-norm of the state of switched dissipative Hamiltonian system converges to zero with the time increasing, and presents two sufficient conditions for the asymptotical stability under arbitrary switching paths. Utilizing these new results, this paper also obtains two useful corollaries for the asymptotical stability of switched nonlinear time-invariant systems. Finally, two examples are studied by using the new results proposed in this paper, and some numerical simulations are carried out to support our new results.

NON-EQUILIBRIUM STATIONARY STATE IN CHEMICAL REACTION OF SiO_2/Fe AT INTERFACE OF SLAG/METAL AND ITS STABILITY DURING ARC WELDING

For characteristics of open and far from thermodynamic equilibrium in welding chemical reaction, a new kind of quantitative method, which is used to analyze direction and extent for chemical reaction of SiO2/Fe during quasi-steady state period, is introduced with the concept of non-equilibrium stationary state. The main idea is based on thermodynamic driving forces, which result in non-zero thermodynamic fluxes and lead to chemical reaction far away from thermodynamic equilibrium. There exists certain dynamic equilibrium relationship between rates of diffusion fluxes in liquid phase of reactants or products and the rate equation of chemical reaction when welding is in quasi-steady state. As result of this, a group of non-linear equations containing concentrations of all substances at interface of slag/liquid-metal may be established. Moreover the stability of this non-equilibrium stationary state is discussed using dissipative structure theory and it is concluded theoretically that this non-equilibrium stationary state for welding chemical reaction is of stability.

Role of Convection Flow on the Pattern Formation in the Drying Process of Colloidal Suspension

We study the macroscopic drying patterns of aqueous suspensions of colloidal silica spheres. It was found that convection strength can influence pattern formation. Uniformed films are obtained at weaker convection strength. In addition, we make clear that it is not reasonable to discuss individually the effect of temperature and humidity on the colloid self-assembly. The physical mechanism is that these factors have relationship with the evaporation rate, which can affect the convection strength.

Analysis of Venezuela's oil-oriented economy: from the perspective of entropy

To investigate the efficiency and stability of Venezuela＇s oil-oriented economy, this paper applied entropy to the analysis.Based on this method, Venezuela＇s oil-centered industry, inefficient regulatory system, and insensitive response to external changes are recognized as an increase in the country＇s entropy. According to these facts, a dissipative structure model is constructed to analyze the efficiency and stability of the Venezuela＇s economic system. The results show that financial assistants（fund flow）, policy reform（policy flow）, and advanced technology（technology flow） can perform as negative entropy inflows（NEIFs）. These NEIFs will promote a series of influence and feedback reactions, which will contribute to recovering Venezuela＇s system efficiency and stability.

Dynamic Mechanism of Migmatization in the Dabie Complex, Northeastern Hubei, China

On the basis of the detailed field work, compositions and contents of plagioclase and K - feldspar,determination of ordering degree, statistical analysis of plagioclase elongation index, mass-balance calculation and mineral spatial distribution and geochemistry, it is concluded that the migmatites in the Dabie complex are characterized by the presence of thermocenters. There are regular changes in mineral character in the migmatites from the centers outwards. The dominant genetic mechanism is anatexis and metasomatism, whose intensities decrease from the centers outwards. Finally, according to the simulated experiment on Liesegang' s rings and non-linear dynamics (dissipative structure theory), the dynamic mechanism of migmatization is profoundly expouded as consisting of the early-stage metasomatism induced by the thermal anomaly, the cardinal-stage anatexis induced by the early-stage matasomatism and finally the last-stage post-anatexis metasomatism.

Nonlinear Dynamic Characteristics of Combustion Wave in SHS Process

The characteristic of combustion wave and its change were analyzed by numerical value calculation and computer simulation, based on the combustion dynamical model of SHS process. It is shown that with the change of condition parameters in SHS process various time-space order combustion waves appear. It is concluded from non-liner dynamical mechanism analysis that the strong coupling of two non-linear dynamical processes is the dynamical mechanism causing the time-space order dissipation structures.

Dissolution Dynamics of Grossularite and Hedenbergite

The relationship between dissolution rate and pH is determined by carrying out dynamic experiments of hedenbergite and grossularite dissolution .The dissolution reaction equations are established .The dissolution processes of two minerals are simulated by using the theory of multi-phase and mufti-component chemical equilibrium . The results bring light to the mechanism of dissolution processes .Due to incongruent dissolution of two minerals when the dissolution processes reach a metastable supersaturation critical point new metastable minerals can be formed in the system .The experiments showed that dissolution of grossularite and hedenbergite consumes H+ and then makes pH value of solution high . In turn , precipitation of metastable minerals makes pH value low .Precipitation of metastable minerals has a catalytic effect for dissolution of reacting minerals in special time .Precipitation and dissolution carried out alternately in the system and it causes periodic oscillation of pH values with reacting time . This is the dissipative structure or self-organization happened in the processes of mineral dissolution.

THE EFFECT OF THE NEGATIVE ENTROPY FLOW ON THE ORGANIZATION OF ATMOSPHERIC DISSIPATIVE STRUCTURES IN NON-EQUILIBRIUM CONDITIONS

The entropy balance equation that describes the entropy budget of atmospheric systems is derived from the Gibbs relation.The distribution of the entropy flows of a west-Pacific typhoon and a Bengal-Bay cyclone is calculated and thus the dissipativity of the atmospheric systems is revealed.