Thermodynamics of some ZrO_2-containing ceramics

1IntroductionZrO2-containing ceramics receive extensive attentionbecause of their great i mportance in science and tech-nology[1,2].Zirconia doped with divalent or trivalentoxides has been proved to be an i mportant solid elec-trolyte,finding wide usage in oxygen sensors and fuelcells.It is also well known that Y2O3-stabilized tetra-gonal ZrO2polycrystals(Y-TZP)possess excellent me-chanical properties at roomtemperature,combining astrength higher than1000MPa and a toughness be-tween6MPa·…     

超声波检测非金属材料的研究与开发

该文阐述了开展非金属材料无损评价的必要性，提出了研究非金属材料超声检测的设想，以及混凝土结构抗冻性的超声检测方法，可供有关研究人员参考。     

教学督导:提高教育教学质量的重要手段

教学质量是学校发展的生命线,教学督导是学校加强教学管理、规范教学过程、深化教学改革、提高教学质量的重要措施和手段。为了更好地发挥督导在教学工作中的作用,需坚持六个原则,处理好四个关系,实现以高尚的师德建构督导形象,以严格的纪律营造和谐督导,以教学规章作为督导尺度。     

利用高阶偏导数对二元函数极值的判定

用二阶偏导数来判定函数f(x,y)在其驻点(x,y_0)处的极值,有时可能有判别式f_(xy)~2(x_0,y_0)-f_(xx)(X_0,y)·f_y(x,y_0)等于零的情况.这时,原来的判别法失效,从而需要作出进一步的考察.为此,本文特给出一种利用一般的高阶偏导数的判别方法.设函数f(x,y)在点(x,y_0)处可展开成n阶泰勒公式,并将其写成△f=P(h,k)+ε.式中P_n(h,k)=sum from m=1 to n(1/(m+1)!)(h((?)/(?)x)+(k(?)/(?)y))~(m 1)f(x,y_0);当ρ趋于零时ε趋于零.同时还设函数f(x,y)在点(x,y_0)处所有阶数不大于某个正整数N的偏导数都等于零,或在点(x,y_0)的某个邻域内所有阶数大于N+1的偏导数都恒等于零.那末,二元函数极值的高阶偏导数判别法可简单地归结为:若P_N(h,k)恒正或恒负,则f(x,y)在点(x_0,y_0)取得极值;若P_N(h,k)有正有负,则f(x,y)在点(x_0,y_0)处不取极值.     

关于多元函数的一致可微性

本文主要研究了多元函数一致可微与偏导数一致连续的一个关系,即偏导数均一致连续,则函数一致可微.并且给出了函数在无界区域上的一个特征.     

二次无理数的连分数

给出了以下几个结果：1.给出了√n（1/2）的连分数展式的简便算法.2.证明了√n（1/2）连分数循环节结构的中心对称性.3.给出了一般二次无理数（a＋√n（1/2））/b的连分数算法.     

广义PC方程的孤立波解

为了进一步研究Pochha mmer-Chree方程孤立波解的特性,考虑了Pochhammer-Chree方程广义形式的孤立波解的存在性．运用双曲函数法和指数函数法求出广义Pochhammer-Chree方程的孤立波解,并给出此方程多个新的显式精确孤立波解,表明广义Pochhammer-Chree方程的孤立波解是存在的,也说明双曲函数法和指数函数法是求方程孤立波解的有效工具．     

预成低位中空赝复体的制作

上颌骨因肿瘤切除后，常会造成牙列缺损和部分上颌骨缺损，严重影响患者的语言，吞咽，咀嚼等生理功参。术后采用低位中空阻塞器的预成赝复体可以保护创面及防止感染，减少软组织的挛缩，恢复吞咽功能，防止发音改变，及时恢复外形和对患者心理起安慰作用。     

Organization of knowledge ecosystems: Prefigurative and partial forms

This paper provides a unique perspective on knowledge ecosystems by studying their organization. Grounded in empirical evidence, we propose that knowledge ecosystems consist of users and producers of knowledge that are organized around a joint knowledge search. A distinction is drawn between knowledge ecosystems searching for a knowledge domain and those searching within an identified knowledge domain, respectively characterized as prefigurative and partial forms of organizing. In a knowledge ecosystem organized in prefigurative form (to identify a knowledge domain), actors whose participation is affiliated, self-resourced, and unobliged probe that domain to identify and establish shared knowledge as a basis for collective actorhood, with no formal rules or coordination mechanisms. In a knowledge ecosystem organized in partial form (where a knowledge domain has already been identified), actors search and reveal problem- and solution-related knowledge, participating though formal membership and access to resources, and their contributions are monitored. The present study contributes to the literature by 1) specifying the distinct types of joint search performed by knowledge ecosystems; 2) considering how the nature of joint search affects how knowledge ecosystems are organized; and 3) distinguishing two forms of organizing knowledge ecosystems, with a focus on participation and coordination.     

Learning from and Reacting to School Inspection – Two Swedish Case Narratives

Throughout Europe, school inspection has become a visible means of governing education. This education and inspection policy is mediated, brokered, interpreted, and learned through networked activities where the global/European meet the national/local, giving national and local “uptake” a variety of characteristics. We explore the local features of this “uptake” as processes of learning in the interaction between schools and inspectors in Sweden. Drawing theoretically on Jacobsson’s notion of governing as increasingly done through meditative activities and on Leontiev’s activity theory, we suggest that school actors learn compliance through diverse emotions provoked by inspection processes in different local settings. Based on observations of inspections, interviews with teachers, head teachers and inspectors, documents, reports, and decisions, we portray how governing education is done through inspection processes in two Swedish schools. The case narratives underscore the importance of local context in these governing and learning processes.