The mechanism of solid - state displacement reaction has been studied , the solid - state displacement reaction path has been analyzed , the mechanical properties of composites has been tested Mo - si - c三元系穩(wěn)定性化學(xué)勢(shì)相圖是定量分析mo _ 2c - si固態(tài)置換反應(yīng)反應(yīng)路徑的重要手段。
Therefore , it is impossible that the microstructure of mosi2 - sic composites prepared by solid - state displacement reaction are interpenetrating structure . 6 因此,在1200通過(guò)固態(tài)置換反應(yīng)原位制備的mosi _ 2 - sic復(fù)合材料的微觀組織不可能是內(nèi)聯(lián)型組織( interpenetratingstructure ) 。
A new type of structure of the solid - stale displacement reactions which named spiral - mtergrowth - aggregate structure was discovered in the mo2c - si diffusion couple and was considered as the result of spinodal - decomposition continuous phase - transformation 昆明理工大學(xué)博士學(xué)位論文2002 . 5摘要6 .初步發(fā)現(xiàn)了一種新的固態(tài)置換反應(yīng)形貌結(jié)構(gòu):螺旋共生束集型結(jié)構(gòu)。
4 . experimental data analysis and theoretical calculation indicated that the interface micro - structure of the solid - state displacement reaction between mo2c and si can be explained properly by the new theoretical model : rate - control - elements convergent diffusing model 實(shí)驗(yàn)數(shù)據(jù)分析和理論計(jì)算表明,本文提出的“速率控制元素非平行擴(kuò)散模型”可以很好地解釋mo _ 2c - si固態(tài)置換反應(yīng)的微觀界面結(jié)構(gòu)。
7 . the precise interface analysis shows that the growth of the parallel rod - aggregate sic is self - organiae appearance of non - equilibrium system . the precise analysis of interlace model of solid - state displacement reaction needs method of non - equilibrium thermodynamic 7 .精致界面模型分析指出,平行束集狀sic的生長(zhǎng)屬于非平衡系統(tǒng)的自組織現(xiàn)象,固態(tài)置換反應(yīng)界面模型的嚴(yán)密分析還需要引入非平衡態(tài)熱力學(xué)的概念方法。
At the same time , it brings the greater displacement reaction , lower energy - dissipation capacity and badly ductility ability etc . the unbonded partially prestressed concrete flat - beam frame structure has been used in the practice project in our country , but the aseismatic study of this structure is not perfect at present , study on theory is lagged behind the demand of engineering apply . it has important theoretic meaning and applied value to go deep into the examinational study about the prestressed concrete flat - beam frame structures 近年來(lái)國(guó)內(nèi)已經(jīng)開(kāi)始在實(shí)際工程中采用無(wú)粘結(jié)部分預(yù)應(yīng)力混凝土扁梁框架結(jié)構(gòu),但是目前對(duì)這種結(jié)構(gòu)形式的抗震研究工作還不完善,理論研究已滯后于工程應(yīng)用的需要,因此深入進(jìn)行扁梁框架結(jié)構(gòu)的研究,在經(jīng)濟(jì)合理的情況下確保該結(jié)構(gòu)的抗震安全性具有重要的理論意義和應(yīng)用價(jià)值。
Moreover , reaction path analysis was accomplished on the fundamental base of the theoretical calculation for mojsi / t phase - interface in the diffusion couple mo2c - si at 1200c . 5 . interface stability analysis of solid - state displacement reaction shows that the layered structure of solid - state displacement reaction between mo2c and si ( fig . 6 . 8 ) is not stable 利用模型進(jìn)行的1200 , mo _ 2c - si擴(kuò)散偶mo _ 4si _ 3 / t相界面的分析計(jì)算,為反應(yīng)路徑的細(xì)致分析奠定了堅(jiān)實(shí)基礎(chǔ),這也是該理論模型應(yīng)用于實(shí)際束集型結(jié)構(gòu)分析的引人注目之處。
The stabilized chemical potential diagrams combined with the equilibrium phase diagrams of mo - si - c ternary system arid the principles of thermodynamic , kinetic , mass - balance could be applied to analyzing and judging reaction paths of in situ synthesis of mosi2 - sic composites through solid - state displacement reactions theoretically . 3 該相圖結(jié)合平衡相圖和熱力學(xué)、物料平衡、動(dòng)力學(xué)原則,可以作為分析和判斷固態(tài)置換反應(yīng)原位合成mosi _ 2 - sic復(fù)合材料反應(yīng)路徑的理論依據(jù)之一,并從理論上分析了固態(tài)置換反應(yīng)原位合成mosi _ 2 - sic復(fù)合材料可能的反應(yīng)路徑。
A new interface - perturbation model of solid - state displacement reactions ternary system is suggested and the interface - stability criterion is derived in the form of chemical potential if the chemical potential of rate - control - element at frontier of tiny perturbative zone goes up less than 20 . 7 % , linear interface will grow up stablly and form layered structure ; if it goes up more than 20 . 7 % , linear interface is not stable and will form aggregate structure 通過(guò)建立界面擾動(dòng)模型,推導(dǎo)了三元固態(tài)置換反應(yīng)系界面穩(wěn)定性的化學(xué)勢(shì)梯度判據(jù)。結(jié)果表明:如果擾動(dòng)微區(qū)前沿速率控制元素的化學(xué)勢(shì)梯度升高小于20 . 7 ,平面界面穩(wěn)定長(zhǎng)大,將形成層狀結(jié)構(gòu);若大于20 . 7 ,平面界面不穩(wěn)定長(zhǎng)大,將形成束集型結(jié)構(gòu)。