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Asymptotic Behavior of the Lipschitz-1/2 Modulus of the PL-process for Truncated and Censored Data 被引量:1
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作者 YongZHOU GuoFuWU XueLeiJIANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2003年第4期729-738,共10页
In this paper, we give a detailed description of the local behavior of theLipschitz-1/2 modulus for cumulative hazard process and PL-process when the data are subject to lefttruncation and right censored observations.... In this paper, we give a detailed description of the local behavior of theLipschitz-1/2 modulus for cumulative hazard process and PL-process when the data are subject to lefttruncation and right censored observations. We establish laws of the iterated logarithm of theLipschitz-1/2 modulus of PL-process and cumulative hazard process. These results for the PL-processare sharper than other results found in the literature, which can be used to establish theasymptotic properties of many statistics. 展开更多
关键词 truncated and censored data oscillation modulus lipschitz-1/2 modulus PL-process cumulative hazard process law of the iterated logarithm
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2D-C/SiC高温弹性模量的预测 被引量:6
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作者 张歌 张程煜 +2 位作者 乔生儒 韩栋 李玫 《机械强度》 CAS CSCD 北大核心 2013年第1期94-99,共6页
平纹碳布(正交纤维)经过叠层得到二维纤维预制体,预制体通过化学气相渗透法沉积热解碳界面和SiC基体,得到二维编织碳纤维增强碳化硅复合材料(2D-C/SiC)。将纤维与热解碳层进行一体化考虑,把基体与孔隙进行一体化考虑,分别计算纤维的就... 平纹碳布(正交纤维)经过叠层得到二维纤维预制体,预制体通过化学气相渗透法沉积热解碳界面和SiC基体,得到二维编织碳纤维增强碳化硅复合材料(2D-C/SiC)。将纤维与热解碳层进行一体化考虑,把基体与孔隙进行一体化考虑,分别计算纤维的就位模量和基体的有效模量;考虑基体和纤维的模量随温度的变化,在混合定则的基础上,将横向纤维当作孔隙、将横向纤维当作基体和1/2混合定则对2D-C/SiC进行三种简化,预测2D-C/SiC复合材料在室温和高温下的弹性模量。与试验结果进行比较发现,利用1/2混合定则预测的2D-C/SiC在室温和高温下的弹性模量与试验值最接近。 展开更多
关键词 温度2D-C SIC复合材料 就位模量 有效模量1 2混合定则
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用作人工玻璃体的聚乙烯基吡咯烷酮水凝胶的流变性 被引量:10
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作者 谢小莉 刘新星 +2 位作者 童真 曾钫 吴水珠 《功能高分子学报》 CAS CSCD 2000年第4期415-418,共4页
合成了交联的聚乙烯基吡咯烷酮水凝胶 ,考察了凝胶在注射前和经WN12号针 (直径 1.18mm)注射后的粘弹性。注射前 ,所有试样表现出交联网络的特征 ,即G′ >G″且对ω的斜率接近零 ,并且随交联剂用量降低 ,储存模量和回弹性减小。注射... 合成了交联的聚乙烯基吡咯烷酮水凝胶 ,考察了凝胶在注射前和经WN12号针 (直径 1.18mm)注射后的粘弹性。注射前 ,所有试样表现出交联网络的特征 ,即G′ >G″且对ω的斜率接近零 ,并且随交联剂用量降低 ,储存模量和回弹性减小。注射后 ,部分试样模量急剧减小 ;未加交联剂的试样粘弹性保持不变 ;仅有样品B8注射后网络结构破坏较小 ,粘弹性变化很小且保持了注射前良好的回弹性 。 展开更多
关键词 人工玻璃体 聚乙烯基吡咯烷酮 水凝胶 流变性
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温度对硅纳米薄膜杨氏模量的影响 被引量:12
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作者 谭一云 于虹 +1 位作者 黄庆安 刘同庆 《电子器件》 CAS 2007年第3期755-758,共4页
采用分子动力学方法计算了100K、300K、400K和500K四个温度下硅纳米薄膜[110]与[110]两个方向上的杨氏模量.结果表明,[110]与[110]两个方向杨氏模量有较大差别,约为25GPa;[110]与[110]的杨氏模量随温度变化的斜率几乎一样,为-0.007Gpa/K... 采用分子动力学方法计算了100K、300K、400K和500K四个温度下硅纳米薄膜[110]与[110]两个方向上的杨氏模量.结果表明,[110]与[110]两个方向杨氏模量有较大差别,约为25GPa;[110]与[110]的杨氏模量随温度变化的斜率几乎一样,为-0.007Gpa/K.研究还表明,[110]与[110]两个方向具有几乎相等的热膨胀系数,量级在10-6/K. 展开更多
关键词 杨氏模量 硅{100}表面 (2×1)dimer重构 分子动力学
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循环荷载下粉质中液限黏土和粉煤灰土的动剪强度研究 被引量:6
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作者 魏海斌 刘寒冰 +2 位作者 高一平 方瑛 李长雨 《岩土力学》 EI CAS CSCD 北大核心 2007年第9期1927-1930,共4页
通过对路基填料粉质中液限黏土和粉煤灰土的动力循环荷载试验,分析了粉质中液限黏土和粉煤灰土1:2的动力特性,得出了动剪强度与循环荷载次数间的变化规律以及动模量与动应变的关系表达式。研究结果表明:粉煤灰土1:2动剪强度优于粉质中... 通过对路基填料粉质中液限黏土和粉煤灰土的动力循环荷载试验,分析了粉质中液限黏土和粉煤灰土1:2的动力特性,得出了动剪强度与循环荷载次数间的变化规律以及动模量与动应变的关系表达式。研究结果表明:粉煤灰土1:2动剪强度优于粉质中液限黏土,可以作为路基填料。 展开更多
关键词 粉质中液限黏土 粉煤灰土 动三轴试验 动剪强度 动模量
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Choice of an Advanced Rheological Model for Modeling the Viscoelastic Behavior of Hot Mixtures Asphalt (HMA) from S&eacute;n&eacute;gal (West Africa)
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作者 Mouhamed Lamine Ché rif Aidara +1 位作者 Makhaly Ba Alan Carter 《Open Journal of Civil Engineering》 2015年第3期289-298,共10页
The main purpose of this article is to choose among advanced rheological models used in the French rational design, one that best represents the viscoelastic behavior of asphalt mixtures mixed with aggregates of Seneg... The main purpose of this article is to choose among advanced rheological models used in the French rational design, one that best represents the viscoelastic behavior of asphalt mixtures mixed with aggregates of Senegal. The model chosen will be the basis for the development of computational tools for stress and strain for Senegal. However, the calibration of these models needs complex modulus test results. In opposition to mechanical models the complex modulus can directly characterize the viscoelastic behavior of bituminous materials. Here determination is performed in the laboratory by using several types of tests divided into two groups: homogeneous tests and non-homogeneous tests. The choice of model will be carried out by statistical analysis through the least squares method. To this end, a study was carried out to “Laboratory of Pavement and Bituminous Materials” (LCMB) with asphalt concrete mixed with aggregate from Senegal named basalt of Diack and quartzite of Bakel. In this study, the test used to measure the complex modulus is the Canadian test method LC 26-700 (Determination of the complex modulus by tension-compression). There mainly exist two viewing complex modulus planes for laboratory test results: the Cole and Cole plane and the Black space. The uniqueness of the data points in these two areas means that studied asphalt concretes are thermorheologically simple and that the principle of time-temperature superposition can be applied. This means that the master curve may be drawn and that the same modulus value can be obtained for different pairs (frequency-temperature). These master curves are fitted during the calibration process by the advanced rheological models. One of the most used software in the French rational design for the visualization of complex modulus test results and calibration of rheological models developed tools is named Visco-analysis. In this study, its use in interpreting the complex modulus test results and calibration models shows that, the studied asphalt concretes are thermorheologically simple, because they present good uniqueness of their Black and Cole and Cole and Black diagrams. They allow a good application of the principle of time temperature superposition. The statistical analysis of calibration models by the least squares method has shown that the three studied models are suitable for modeling the linear viscoelastic behavior of asphalt mixtures formulated with the basalt of Diack and the quartzite of Bakel. Indeed their calibration has very similar precision values of “Sum of Squared Deviation” (SSD) about 0.185. However, the lower precision value (0.169) is obtained with the 2S2P1D model. 展开更多
关键词 Complex and Dynamic modulus VISCOELASTIC Huet Huet-Sayegh 2S2D1P Visco-Analyse Sum of Squared Deviation
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