process trustworthiness as a capability indicator for measuring and improving software trustworthiness

Chinese Acad Sci, ISCAS Lab Internet Software Technologies

Measuring the electronic decay constant of alkanedithiols by electrochemical impedance spectroscopy

Several methods have been used for the measurement of the electronic decay constant (beta) of organic molecules. However, each of them has some disadvantages. For the first time, electrochemical impedance spectroscopy (EIS) was used to obtain the 18 value by measuring the tunneling resistance through alkanedithiols. The tunneling resistance through alkanedithiols increases exponentially with the molecular length in terms of the mechanism of coherent nonresonant tunneling. beta was 0.51 +/- 0.01 per carbon.

A new method of measuring alcohol clusters in polyimide membrane: combination of inverse gas chromatography with equilibrium swelling

A new method of measuring the mean size of solvent clusters in swollen polymer membrane is presented in this paper. This method is based on a combination of inverse gas chromatography (IGC) and equilibrium swelling. The mechanism is that weight fraction activity coefficient of solvent in swollen polymer is influenced by its clusters size. The mean clusters size of solvent in swollen polymer can be calculated as the quotient of the weight fraction activity coefficient of clustering system dividing the weigh fraction activity coefficient of non-clustering system. In this experiment, the weigh fraction activity coefficient of non-clustering system was measured with IGC. Methanol, ethanol and polyimide systems were tested with the new method at three temperatures, 20, 40, and 60degreesC. The mean clusters size of methanol in polyimide was five, four, and three at each temperature condition, respectively. Ethanol did not form clusters (the mean clusters size was one). In contrast to the inherent narrow temperature range in DSC, XRD, and FTIR methods, the temperature range in IGC and equilibrium swelling is broad. Compared with DSC. XRD. and FTIR, this new method can detect the clusters of solvent-polymer system at higher temperature.

A novel electrochemical method for simultaneously measuring diffusion coefficient and ion transference number

This paper introduces a new method to estimate the diffusion coefficient and transference number of a salt or an electroactive ion in a solution with little or no supporting electrolyte. The above two parameters can be obtained from a single potential step experiment without previous knowledge of either one. It would appear that the method could also be used in the study of ion transport in a high viscosity solvent or a solid electrolyte. (C) 1998 Elsevier Science S.A.

ON THE ANALYSIS OF THE END-NOTCHED FLEXURE SPECIMEN FOR MEASURING MODE-II FRACTURE-TOUGHNESS OF COMPOSITE-MATERIALS

This paper deals with the correction of mode II strain energy release rate, G(II), of composite laminates measured with the end-notched flexure (ENF) specimen. A derivation is given of the expressions for compliance and strain energy release rate, in whic

四坐标位姿测量仪设计研究与误差分析

四坐标位姿测量仪是针对某轻型汽车底盘前悬置横梁上四孔位姿测量而设计的新型仪器·该测量仪以六自由度并联机构作为执行机构 ,能够迅速准确地到达被测孔的实际位置 ,测量头具有对非测量参数误差的自适应和自调整能力·采用比较法实现参数测量·该机构结构新颖 ,测量效率高·系统分析研究了各因素造成的测量误差 ,指出了减小测量误差的措施 ,从而为精确设计测量仪提供了可靠依据·