| 1. | Numerical simulation of surface crack propagation considering the crack closure effects and the three - dimensional stress constraints
考虑闭合效应和三维应力约束的表面裂纹扩展模拟 |
| 2. | More obvious crack - closing effect on am50 is thought as the key reason for am50 ' s higher fatigue life ( n ) , compared with az91
裂纹闭合效应比az91好被认为是am50试样比az91疲劳寿命高的根本原因。 |
| 3. | During the course of the fatigue crack propagation , there lies crack - closing effect in both two alloys and the main crack - closing mechanic is plasticity - induced one
裂纹扩展过程当中，两种合金均存在着裂纹闭合效应；塑性诱发的裂纹闭合是镁合金的主要裂纹闭合机制。 |
| 4. | ( 3 ) the finite element model , in which the contact between the crack lines is considered , is more accurate than traditional fe model to simulate the crack growth and crack closure
( 3 )建立了考虑裂纹面接触的有限元模型，较传统不考虑裂纹面接触的方法更适于模拟裂纹扩展和裂纹闭合效应。 |
| 5. | ( 3 ) both oxide - induced closure and embrittlement of grain boundaries take place for 2 - cr1mo and 2 - cr1mov at high temperature . the change of fatigue crack growth rates with temperature is not so evident as 316land 16mnr
裂纹表面氧化引进的闭合效应和晶界脆化相对比较均衡，裂纹扩展速率随着温度升高的变化没有铁素体和奥氏体材料明显。 |
| 6. | Based on the theory of compositional data analysis proposed by aitchison in 1982 , a multiple nonlinear statistical method originating from the " logratios " approach to the statistical analysis of compositional data is put forward in this paper
从分析基因多态性数据的分布和结构特徵入手，文中指出了基因多态性分布具有“闭合数据”的特点，分析了由于“闭合效应”的影响，经典多元线性方法用于群体遗传结构分析所面临的困难。 |
| 7. | The distribution and structure of the allelic polymorphism data are analyzed and it is pointed out that the distribution of allelic polymorphism data reveals the characteristic of closed data ( also named as compositional data or data of constant sum ) it is interpreted that the correlation structure of the allelic polymorphism data contains null correlations introduced by " closure " and the statistical distribution of the data is not normal because of its constant row sum , which resulted in great difficulties in analyzing the data with traditional multiple linear statistical methods such as principal component analysis , factor analysis , cluster analysis and canonical correlation analysis
摘要长期以来，对于多维基因多态性数据的多元统计分析，如计算遗传距离时所用的聚类分析、分析群体遗传结构时所用的主成分分析、因子分析和典型相关分析等，一直应用为无约束条件数据而设计的经典多元线性分析方法，并没有注意基因多态性数据的“闭合效应”所带来的问题。 |
| 8. | ( 1 ) oxidation on the crack surface of 16mnr increase with temperature . oxidation mainly takes place on the crack surfaces at 150 ~ 300 , which it is serious both on the crack surfaces and in the grain boundaries at 425 . oxide - induced closure at 150 ~ 300 results in the drop of crack growth rates
铁素体材料16mnr疲劳裂纹表面的氧化随温度升高而增大，在150和300时裂纹表面氧化引进的闭合效应要比晶界氧化脆化更明显，引起在这个温度范围内的试验疲劳裂纹扩展速率下降。 |
