Dynamic Characteristics of Complex Structure Under and Out of Water

To understand the dynamic characteristics of the whole period of a complex structure‘‘‘‘‘‘‘‘s launching out of water,on the basis of FEM formulations deduced for solving coupled fluid-structure problems with strong-coupled method,FE models used to simulate the structure surrounded with fluid domains are established.The modal ex-periment on the real structure under shallow water shows great sccordance with sinulating results.Based on this verification,dynarnic character parameters of all FE models simulating each phasc of the structure‘‘‘‘‘‘‘‘s launching out of water are abstracted with unsymmetric algorithm,which can comprehensively describe the dynamic characters of the structure in its whole working process.Conclusions drawned from these calculations are successfully applied in works of evaluating the structure‘‘‘‘‘‘‘‘s performances and reliabilities.     

Kinematic and Dynamic Characteristics Analysis of Bennett’s Linkage

Bennett’ s linkage is a spatial fourlink linkage, and has an extensive application prospect in the deployable linkages.Its kinematic and dynamic characteristics analysis has a great significance in its...     

Preparation, Fundamental Characteristics and Biosafety Evaluation of Compound rhBMP-2/CPC

To stndy the fundamental characteristics and biosafety of the compound bone morphogenetic protein （ BMP ） and rhBMP- 2/CPC , and to provide a theoretical basis for the compound biologically active artificial bone made of calcium phosphate cement （CPC） and bone morphogenetic protein, simplex CPC was taken as the control group, and the compound with the blending ratio of 1g CPC to 5mg rhBMP-2 was taken as the experimentation group to determine the setting time, compressive, strength, acute toxicological and sub acute toxicological properties. The osteogenic characteristic of compound rhBMP- 2/CPC was measured by making animal model of radio discontinuous defect. The setting time of the two groups meets the clinical requirements, and the compressive strength of the solidified body of bone cement increases along with increasing the immersion time. Compound rhBMP- 2/ CPC has a favorable ostengenic characteristic for animal model of radio discontinuous deject. The fundamental characteristics of the compound rhBMP- 2 phosphate bone cement are basically the same as that of CPC, and also have a favorable biosafety and osteogenesis.     

Preparation, Fundamental Characteristics and Biosafety Evalution of Compound rhBMP-2/CPC

1Introduction Calciumphosphatecement(CPC)isanewtypeof bonesubstituteinrecentyearswithagoodboneconduc tion,absorbability,biologicalcompatibilityandetc.The mechanicalfixationcangraduallyturnintobiologicalfixa tioninitsanaphase[1].Atthesametime,calciumphos phatecementhasbeenprovedtobeagoodcarrierofthe bonemorphogeneticprotein(BMP)[2],whichcanover cometheshortagesthatsimplexBMPwillbedilutedby enchymaanddecomposedbyproteaseafteritsimplanta tionintothehumanbody,anditseffectiveconcentration insom…     

Dynamic Factor Method of Computing Dynamic Mathematical Model for System Simulation

The computational methods of a typical dynamic mathematical model that can describe the differential element and the inertial element for the system simulation are researched. The stability of numerical solutions of the dynamic mathematical model is researched. By means of theoretical analysis, the error formulas, the error sign criteria and the error relationship criterion of the implicit Euler method and the trapezoidal method are given,the dynamic factor affecting the computational accuracy has been found, the formula and the methods of comput-ing the dynamic factor are given. The computational accuracy of the dynamic mathematical model like this can be improved by use of the dynamic factor.     

Investigation of the Dynamic Characteristics of a Rotor Bearing Assembly

ＩｎｖｅｓｔｉｇａｔｉｏｎｏｆｔｈｅＤｙｎａｍｉｃＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆａＲｏｔｏｒＢｅａｒｉｎｇＡｓｓｅｍｂｌｙ￥（刘庆明）（庞志成）ＬＩＵＱｉｎｇｍｉｎｇＰＡＮＧＺｈｉｃｈｅｎｇ（Ｄｅｐｔ．ｏｆＭｅｔｈａｎｉｃａｌＥｎｇｉｎｅｅｒｉｎ...     

Nonlinear Dynamic Characteristics of Combustion Wave in SHS Process

The characteristic of combustion wave and its change were analyzed by numerical value calcula-tion 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.     

Construction and Solution to a New Dynamic Model of Forging Hammers Damping System

ＣｏｎｓｔｒｕｃｔｉｏｎａｎｄＳｏｌｕｔｉｏｎｔｏａＮｅｗＤｙｎａｍｉｃＭｏｄｅｌｏｆＦｏｒｇｉｎｇＨａｍｍｅｒｓＤａｍｐｉｎｇＳｙｓｔｅｍ￥ＬＩＵＧａｎｇ；ＣＨＥＮＷｅｉｍｉｎ；ＣＨＥＮＷｅｉ（刘钢，陈维民，陈威）（Ｄｅｐｔ．ｏｆＭａｔｅｒｉａｌＳ...     

Characteristics of Heavy Minerals in Tertiary System of Western Qaidamu Basin

According to tectonic position and mineral inclusions, supply resource in western Qaidamu basin is divided into the front of Aerjinshan mountain and the front of Qimantageshan mountain. The former is mainly composed of zircon, garnet inclusions, indicating that its mother rocks are mainly metamorphic rocks. Gas and zircon, iron ore,carbon grain inclusions is common in the front of Qimantage mountain, indicating that its mother rock are mainly magmatite and mixed metamorphic rocks. The supply resource is abundant and tectonic movement is active in the joint of the two mountains. The western Qaidamu basin is further divided into 6 heavy mineral sub-regions according to their features of association and stable coefficient of heavy mineral. They are approximately corresponding to their sedimentary environment. Of the 6 sub-regions, the unstable region is corresponding to fluvial fan, middle stable region is corresponding to river-alluvial plain-delta, stable region is corresponding to river-alluvial plain -delta-offshore.The fragment transported distance is presumed based on stable coefficient. In vertical, stable coefficient of heavy mineral becomes small from Xiaganchai formation to Xiayoushashan formation, indicating that the supply resource became nearer and nearer.     

Study of Dynamic Robustness of Servo Control System on a Water Press

NomenclatureqLFlowrate[L/min]KqValve flowgainxvValve spool displacement[m]KcValve flow-pressure gain[m3/PaVs]PLLoad pressure[ MPa]VtTotal compression Volume[m3]βeEffective bulk modulus[Pa]A1Piston rod areaxpPiston rod displacementCepExternal leakage coefficientmtTotal movingload mass[kg]BpCylinder viscous coefficientFLLoad force[N]KceTotal flow-pressure coefficientωhSystemnatural frequencyζhHydraulic damping ratio1 IntroductionThe development of heavy equipment manufacturing t…     

Characteristics and Mechanism of Scrooping Sound of Silk

In this study a measurement instrument of scrooping sound has been develope.Thefollowing results were obtained by means of measurement and analysis for the frequencyspetrums of scrooping sound of silk : 1 The scrooping vibration is mainly composed of S- S( stick-slip vibration) ,F- V(free damping vibration) and S- C( characteristic high frequency vibration) vibrations. 2 The scrooping sound of silk mainly depends on F- V and S- S vibrations and be-longs to lower frequency sound,while the effect of S- C vibration is limited. 3 The wave and the vibration equations as well as some fromulas of relative physicalproperties have been established on the discussion about the stick- slip vibration. 4 The critical condition producing stick- slip vibration is( μs- μd)> 0.     

The Analysis of the Dynamic Equilibrium State in Linear Control System

This paper discusses not a point of equilibrium to free system,but a certain family of equilibrium state of dynami- cal system with inputs.This equilibrium state depends on the input,so it is called the dynamic equilibrium state.The expression of the dynamic equilibrium state can be given under some certain condition.With deductions and proofs in linear control system,es- tablish the expression of the dynamic equilibrium state in two cases,where the linear systems are nonsingular or singular.Also pre- sent the concept and the condition of the controllability of the dynamic equilibrium state.The controllability of the dynamic equilib- rium state is different from the controllability of the state to system,but these two are closely related.     

Comparison of Conventional and Microwave-assisted Synthesis and Characteristics of Aluminum-pillared Rectorite

The synthesis and characterization of aluminum-pillared rectorite were studied. The synthesis was conducted with both conventional heating and microwave irradiation. Microwave irradiation was found to enhanee the intercalation and ion-exchange during synthesis, and to be able to produce the rectorite with a larger d001 aad a better uniformity. The specific surface area is 180 m^2 / g and basal spacing is 3.2 nm.The texture change and thermal and hydrothermal stability of cross- linked rectorite were examined using XRD, FTIR, nitrogen-adsorption and TGA. The experimental results show that the aluminum-pillared rectorite, after calcined at 800℃ for 3 hours, can keep the basal aluminum-silicate texture and would not disperse in water at room or an elevated temperature. The alumimum-pillared rectorite shows a high specific surface area, good thermal and hydrothermal stability, and is promising in applications as catalyst carriers and adsorbents for waste treatment.     

Analysis of Physical and Chemical Characteristics and Influence Factors of UCG

Based on the UCG (underground coal gasification) theory, the “three zones“ which are oxidization zone,reduction zone, and drying zone, were divided; physical and chemical properties of each zone were analyzed. Factors, such as temperature, rate of water pouring, quanzity of air blast, thickness of coal seam, and the operation pressure were discussed. Among the influencing factors, the temperature is the most important one.     

Dynamic Load Flow Used for Electric Power System State and Tendency Analysis

Dynamic load flow technology can simulate actual frequency and load flow change when a load naturally varies and generator units adjust their power output by an adjustment system during a certain time. Dynamic load flow is a basic part of power system state and tendency analysis. In this paper, a dynamic load flow model and its solution method are first presented and discussed. Then, the application of dynamic load flow to a real power system is given as a demonstration.     

Synthesis of Ni/Al System Intermetallic Compound Under the Influence of Pulsating Electric Current

1　IntroductionBecauseofitshighmeltingpoint(16 38℃ ) ,lowden sity(5 .9g cm3 ) ,goodthermalconductivity(4 - 8timestoNi basedthermalloy) ,satisfactoryoxidationresistance ,uniquehigh temperatureproperty (yieldstrengthgrowswithrisingtemperatureinsometemperaturerange) ,NiAlintermetalliccompoundisattractiveasapotentialmaterialforhightemperatureapplications .Theseapplicationsin cludeitsuseinturbinebladesinaircraftenginesorinstationarygasturbines .Self propagatingHigh temperatureSynthesis(SHS)hass…     

Synthesis and Characteristics of Organic Bentonite Gel

1 IntroductionBentonite is composed of hydrous aluminosilicateminerals,the staple of which is montmorillonite . Mont-morillonite is a kind of layered mineral composed of twolayers of Si -Otetrahedron with alayer of Al -Ooctahe-dral in between,whose interlayeris permeated withinter-layer water and exchangeable cations .Byinsertingthe or-ganic long-chain quaternary ammoniumintothe sial inter-layer of montmorillonite ,the organic modified bentonite issynthesized. Then by the reaction between th…     

On Concept of Dynamic Economic System With After－Effects─Research on Dynamic Economic System with After－Effects （Ⅰ）

ＯｎＣｏｎｃｅｐｔｏｆＤｙｎａｍｉｃＥｃｏｎｏｍｉｃＳｙｓｔｅｍＷｉｔｈＡｆｔｅｒ－Ｅｆｆｅｃｔｓ─ＲｅｓｅａｒｃｈｏｎＤｙｎａｍｉｃＥｃｏｎｏｍｉｃＳｙｓｔｅｍ　ｗｉｔｈＡｆｔｅｒ－Ｅｆｆｅｃｔｓ（Ⅰ）ＳＨＡＪｕｚｈｅｎ（沙聚桢）（Ｄｅｐｔ．ｏｆＳ...