关于形式系统(L)*的强完备性

进一步讨论了形式系统L^*中的一般演绎推理及强完备性问题。对于任意的公式集Γ,引入一种新的代数结构—R0(Γ)代数,利用子代数结构,代数滤子理论及次直积分解理论等代数工具,证明了系统L^*的强完备性定理。     

Fredholm模与四元数Cauchy奇异积分算子

运用四元数Cauchy核奇异积分算子理论和C*代数理论,建立了一个Fredholm模结构.     

C~*-代数中方程x+a~*x~(-1)a=1的正定解

应用压缩映射原理证明了 C* -代数中方程 x +a* x-1 a=1的正定解的存在唯一性并给出了正定解的递归叙列及误差估计     

S—空间及Radon空间的表示

本文证明了在扩大的非标准模型中S-空间可完全表示Radon空间。本文还给出一个有限Borel测度空间为Radon空阅的充要条件,另外本文还讨论了S-空间的若干性质,最后本文证明了Radon空间的一个*-有限表示定理。     

有界Heyting代数的模糊LI-理想

理想是研究逻辑代数结构特征的重要工具性概念之一.本文综合运用代数学与模糊集的方法和原理,在有界Heyting代数中引入模糊LI-理想概念并研究其性质.进而讨论了模糊LI-理想与模糊格理想之间的关系,并给出了由一个模糊集生成的模糊LI-理想的表示定理,最后证明了一个给定有界Heyting代数的全体模糊LI-理想之集在模糊集合包含序下构成一个完备Heyting代数.     

有界可换BCK-代数与MV-代数

在有界可换 BCK-代数〈X;*,0〉中定义 x′=N x,x + y =y*Nx,x× y =N ( Ny*x) ,1 MV=0 ,则 ( X,+ ,× ,′,0 MV,1 MV)是一个 MV-代数 ;而在 MV-代数 ( X,+ ,× ,′,0 MV,1 MV)中定义 x*y =x + y′,0 =1 MV,则〈X;*,0〉是一个有界可换 BCK-代数。     

L^＊-Lindenbaum代数的结构与L^＊公理系统的简化形式

证明了L^*-Lindenbaum代数[F]是具有逆序对台对应的有界分配格．得出了L^*中的公理系统的一种简化形式．     

环Z_(pq)上逻辑函数的分解及其应用

为克服一般剩余类环上合数值逻辑函数无统一多项式表示给函数研究工作带来的困难,本文利用中国剩余定理对环Z_(pq)(pq且均为素数)上的pq值随机变量进行了分解;并由此对pq值逻辑函数及其变元进行了CRT-分解,给出了pq值逻辑函数的分解函数的代数标准型,据此可得pq值逻辑函数在CRT-分解意义下的代数标准型;又讨论了pq值相关免疫逻辑函数在CRT-分解意义下的等价判别条件,给出了利用分解函数的代数标准型构造pq值相关免疫逻辑函数的一种方法。     

BR0-代数的无序表示形式及WBR0-代数性质

对BR0-逻辑代数进行了进一步研究,得到了BR0-逻辑代数的一种无序表示形式,使得BR0-代数中的序关系蕴涵于BR0-代数的基本运算⊕和→之中,并根据BR0-代数的无序表示形式提出了WBR0-代数理论,初步地讨论了其中的性质.     

关于代数体函数亏量的椭园定理的推广

文[3]讨论了n值代数体函数的亏量,得出代数体函数的亏量椭园定理。本文将[3]的结果推广到亏小函数。     

R0代数的注记

讨论了R0代数与MV代数的关系，给出了R0代数的一种根。     

R0-代数与BL-代数中的素滤子定理

R1-代数与BL-代数在模糊逻辑的研究中有重要作用,这与布尔代数在经典逻辑中的作用类似。本文通过一个特殊集x^-1F分别给出Ro-代数及BL-代数素滤子的一个等价条件,并给出BL-代数的一个新性质。应用这些结果分别得到Ro-代数与BL-代数的素滤子定理。     

Recent determinations of R/sub H/ in terms of Omega /sub 69-BI/

A system based on a cryogenic current comparator is used to measure the quantized Hall resistance R/sub H/ in terms of Omega /sub 69-BI/, the Bureau International des Poids et Mesures (BIPM) representation of the ohm, with an uncertainty of 1.5*10/sup -8/. This measurement system and the former potentiometric one are in good agreement within their combined uncertainties (5.1*10/sup -8/).<>     

Effect of stress dependent creep ductility on creep crack growth behaviour of steels for wide range of C*

Abstract

In this work, the effect of stress dependent creep ductility on the creep crack growth (CCG) behaviour of steels has been investigated by finite element simulations based on ductility exhaustion damage model. The relationship between the transition region of creep ductility and the transition behaviour of CCG rate on da/dt-C* curves has been examined and the CCG life assessments of components and CCG resistance of materials for a wide range of C* were discussed. The results show that with increasing the transition region size of creep ductility, the transition C* region size on da/dt-C* curves increases. With moving transition region position of creep ductility to high stress region (increasing transition stress levels), the transition C* region on the da/dt-C* curves also moves to high C* region. Decreasing transition stress levels and transition region sizes of creep ductility and increasing the lower shelf and upper shelf creep ductility values can improve the CCG resistance of materials. If the extrapolation CCG rate data from the high C* region or from the transition C* region are used in life assessments of the components at low C* region, the non-conservative or excessive conservative results may be produced. Therefore, the CCG rate data should be obtained for a wide range of C* by long term laboratory tests or numerical predictions using the stress dependent creep ductility and model.     

Effect of CYP2C9 genetic polymorphism on the metabolism of flurbiprofen in vitro

CYP2C9 is an important member of the cytochrome P450 enzyme superfamily, and 57 cytochrome P450 2C9 alleles have been previously reported. To examine the enzymatic activity of the CYP2C9 alleles, kinetic parameters for 4′-hydroxyflurbiprofen were determined using recombinant human P450s CYP2C9 microsomes from insect cells Sf21 carrying wild-type CYP2C9*1 and other variants. The results showed that the enzyme activity of most of the variants decreased comparing with the wild type as the previous studies reported, while the enzyme activity of some of them increased, which were not in accordance with the previous researches. Of the 36 tested CYP2C9 allelic isoforms, two variants (CYP2C9*53 and CYP2C9*56) showed a higher intrinsic clearance value than the wild-type protein, especially for CYP2C9*56, exhibited much higher intrinsic clearance (197.3%) relative to wild-type CYP2C9*1, while the remaining 33 CYP2C9 allelic isoforms exhibited significantly decreased clearance values (from 0.6 to 83.8%) compared to CYP2C9*1. This study provided the most comprehensive data on the enzymatic activities of all reported CYP2C9 variants in the Chinese population with regard to the commonly used non-steroidal anti-inflammatory drug, flurbiprofen (FP). The results indicated that most of the tested rare alleles decreased the catalytic activity of CYP2C9 variants toward FP hydroxylation in vitro. This is the first report of all these rare alleles for FP metabolism providing fundamental data for further clinical studies on CYP2C9 alleles for FP metabolism in vivo.     

Theoretisch-numerische Untersuchungen zu Experimenten mit Kriechrißwachstum

Theoretical-Numerical Investigations of Experiments with Creep Crack Growth Numerical results are presented to calculate the C* -integral that is path independent only in the long-time range. The crack tip modelling – elastic or elastic-plastic – is of minor influence on C* – whereas values of C* depend strongly on the material constants describing the creep law. The agreement between numerically and experimentally determined C* data is rather satisfactory in the secondary creep regime. A line integral R* is proposed that is path independent in the whole time domain.     

嵌有纳米碳颗粒凝胶玻璃的制备及其发光特性

以磷酸三乙酯、硝酸铝和正硅酸乙酯为原料,通过它们的水解制备了ｘＡｌ_２Ｏ_３·ｘＰ_２Ｏ₅·１００ＳｉＯ_２（ｘ＝０．２５～３）凝胶．在６００℃对凝胶进行热处理,使其中的有机基团炭化,从而制备出了镶嵌有碳纳米颗粒的ｘＡｌ_２Ｏ_３·ｘＰ_２Ｏ_５·１００ＳｉＯ_２（ｘ＝０．２５,０．５）凝胶玻璃．在室温下以５３２ｎｍ激光（Ｎｄ：ＹＡＧ）激发,在 ６３０ｎｍ处有一强的发光峰,该发光现象是由镶嵌在凝胶玻璃中的纳米碳颗粒产生的．     

Application of the T-integral and S criteria in finite element analysis of impact damage at fastener holes in graphite/epoxy laminates under compression

This paper illustrates the application of two fracture criteria, Atluri's T^*-integral and Sih's strain energy density factor S for estimating the residual strength of an impact damaged fastener hole in a composite laminate. Finite element analyses are performed, and the magnitude and distribution of T^* and S are determined around the delamination. It is found that the profiles of these distributions are extremely complex and sensitive to the modelling of the stress fields close to the delamination. The effects of local closure, shear moduli and cracktip singularity are investigated. It is also shown that the representation of the stress singularity in the finite element model has a strong effect on the distribution of T^* and S. The distribution of both T^* and S is such that three local maxima occur and are situated at the same locations around the delamination. These locations approximately coincide with the points of maximum growth as revealed by ultrasonic C-scan of the damage growth of several specimens. The T^*-integral is shown to be more sensitive to the values of interlaminar shear moduli than S. The results of the analyses suggest that both the T^*-integral and S criteria may be successfully employed in the prediction of residual strength. However, S is better at predicting the direction of damage growth provided the stress fields near the delamination can be accurately modelled.     

Boundary element analysis of ductile crack growth using the traction-free fundamental solution

A new boundary element formulation in two-dimensional rate-independent plasticity is given. This new formulation uses a so-called traction-free fundamental solution so that the resulting boundary integral equation converges in the normal sense, and more important, a formal differentiation of the boundary integral equation leads to a valid integral representation for the in-plane stress component on the boundary. No finite difference approximation is needed to construct the stress recovery routine. The new boundary element method is then used to solve the problem of quasi-static ductile crack growth. Numerical simulations based on a set of experimental data have been carried out to evaluate a new path-independent integral,T* _M . TheT* _M ,-integral is a modified version of Atluri'sT*-integral. This modified version has an advantage of having a less singular domain integral near the crack flank so that it is numericaly preferable toT*.     

Life assessment of HK40 reformer tube by fracture mechanics

Creep crack growth measurements have been made at 871°C (design temperature) on HK40 steel which was taken from a reformer tube in service for 81000 h. The path-independent integral C* is a proper parameter correlating creep crack growth rates of different specimen geometries. The residual life of the reformer tube was calculated by the equation da/dt with C* and Webster's model. It has been shown that the results by the two methods are consistent.