Structure initiale et propriétés de liquéfaction statique d'un sableInitial structure and static liquefaction properties of sand.

Based on the use of two different preparation procedures for reconstituting triaxial samples of sand, i.e. wet tamping and dry pluviation, significant differences in associated mechanical behaviour are observed on a reference sand with respect to the phenomenon of ‘static’ liquefaction. Wet tamping favours the initiation of liquefaction instability, whereas dry pluviation favours a more stable behaviour, less susceptible to liquefaction. Microscopic observation of corresponding sand specimens allows us to identify two well differentiated structures, i.e., for wet tamping, an irregular structure with predominance of aggregates (aggregated grains) and macropores, very contractant and unstable and, for dry pluviation, a more regular structure, without macropores, more dilatant and more stable. These observations show the importance of further characterization, based on the introduction of appropriate parameters, of the initial structure of sandy materials, strongly dependant upon their mode of formation (natural or artificial). To cite this article: N. Benahmed et al., C. R. Mecanique 332 (2004).     

一种多波长激光晶体消光比测试仪的研究

介绍一种三波长的激光晶体消光比测试仪。该测试仪具有全自动，多波长的特点，其系统消光比优于５０ｄＢ，不确定度小于２％，具有很好的重复性。     

闪光有效光强测定仪研究

论述闪光光源有效光强的测量方法及原理，并详细介绍我所自行研制的闪光有效光强测定仪。文中对仪器的工作原理，结构特点，技术性能和用途给予比较全面的论述，并给出了实测曲线。     

A bootstrap approach to model checking for linear models under length-biased data

In this paper, we propose two bootstrap-based model checking tests for a parametric linear model when data are affected by length-bias. These tests are based on the measure of the discrepancy between nonparametric and parametric estimators for the regression function when the data are drawn under a length-biased mechanism. We consider two different discrepancy measures: the supremum and the integral of the quadratic difference between the parametric and nonparametric estimators.     

A Nonparametric Sequential Test with Power 1 for the Mean of Lévy-stable Laws with Infinite Variance

A nonparametric sequential test with power one for the mean of Lévy-stable laws with infinite variance is given. Our considerations are based on a law of the iterated logarithm for Peng’s estimator [Peng, Stat. Probab. Lett., 52:255–264, 2001] of the mean of heavy-tailed distributions. Our main motivation comes from applications to financial data, and in particular to sequential control of daily asset returns.      

Quality test of a mechanical switching valve for two-dimensional open tubular gas chromatography

A commercially available mechanical micro switching valve has been tested for inertness. The test mixtures used were a modified Grob test and a solution consisting of eight typical aroma compounds, both at the 2-ng level. Cryogenic focusing of the sample after chromatography including one passage through the valve revealed that irreversible interaction of some test substances with valve components was rather small. A composite main peak of a chromatogram from a fruit juice aroma exhibiting a “mixed odor” was selectively transferred (heart-cutting) to a second column and resolved into three peaks. GC-GC/sniffing assigned a minor peak to a substance formerly hidden under the composite peak. Separate heating of the valve during temperature programming of the column was found to be unnecessary.     

关于拟合优度检验的EDF统计量的若干评注(英语)

拟合优度检验是建立统计模型的一个重要手段,很多检验统计量用一个理想样本能达到它们自己的极值,但EDF统计量做不到,这无疑会影响检验的势。在本文中,我们将提出某些调整型EDF统计量,它们具有这些性质,并改进了EDF检验,蒙得卡罗模拟表明,调整型EDF统计量在很多场合要必EDF具有更高的势,特别对重尾的备选分布更是这样,我们还考察了检验的形态与它们的极值点之间的关系。     

Testing whether survival function is harmonic new better than used in expectation

Summary Statistical procedures to test that a life distribution is exponential against the alternative that it is harmonic new better than used in expectation (HNBUE) are considered.     

Historical review on research of kinetics in thermal analysis and thermal endurance of electrical insulating materials

In 1925 a paper on kinetic analysis of data obtained with thermobalances for isothermal mass loss of some natural products for electrical insulation was published. This is the first theoretical and experimental approach to accelerated test of electrical insulating materials and also to kinetic analysis of thermal analysis data at isoconversional points. In succeeeding papers, change in chemical composition and kinetics under temperature change were dealt with. A historical review of these two topics is described in this review article, especially on the basic concept commonly induced for these two fields.     

GeSi／Si应变超晶格探测器的制作

介绍ＧｅＳｉ／Ｓｉ应变新材料探测器的制作方法，它不仅与Ｓｉ微电子工艺相兼容，而且还可调节Ｇｅ含量使其禁带宽度满足现代光纤通信器件的要求。