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51.
We have developed a parameterization method which linearizes the relationship between local magnetic moment and the 3d L3/L2 "white line" ratio as observed in electron energy loss spectroscopy or X-ray near edge absorption spectroscopy. We first establish that the parameterization linearizes an existing theoretical result for ratio versus moment. We then test our method on data sets for which a white line ratio has been previously published by other authors, who have studied a series of compounds using a consistent deconvolution procedure. Finally, we apply our linearization method to the observed ratios of a series of 3d transition metals, and to the Cr L edges for a Au(x)Cr(1 - x) alloy. In addition we obtain, for the first time, experimental results on the Au L3 and L2 edge white lines of this alloy system. These results are consistent with a model in which the large local moment in this system is not limited to Cr dopants, but extends into the gold matrix.  相似文献   
52.
The authors review the limits of nanometer-scale gate electrode (nano-gate) fabrication. The technology to fabricate nano-gates has become increasingly important in recent years as the scaling limits of conventional electronic devices and the quantum effects of novel devices are investigated. Consistent with the technology used to fabricate virtually all of the smallest devices to date, the emphasis is on the resolution limits of electron beam lithography and associated ultrahigh resolution resists. Recent results of directly patterning SiO2 with nanometer-scale resolution by e-beam exposure through a sacrificial layer are also presented. Because the high resistance normally associated with nanometer-scale electrodes seriously limits the performance of high-frequency devices, various techniques to reduce the gate resistance are compared  相似文献   
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A method is described for determining residues of an experimental herbicide, based on Lenacil (3-cyclo-hexyl-5,6-trimethyleneuracil) in soil and sugar beets. The procedure is based on the gas chromatographic measurement of Lenacil after extraction from the substrate with an alkaline solution and subsequently partitioned into an organic solvent. Intermediate cleanup steps are required. The sensitivity of the method is about 0·04 ppm based on a 25-g sample, with an average recovery of better than 80%.  相似文献   
55.
A new member of human beta-chemokine cDNA was isolated and named leukotactin-1 (Lkn-1). Lkn-1, along with murine macrophage inflammatory protein-related protein-1 and -2, defines a subgroup of beta-chemokines based on two conserved cysteines in addition to the four others conserved in all beta-chemokines. The putative mature Lkn-1 is composed of 92 amino acids with a calculated m.w. of 10,162. The Lkn-1 gene was mapped to human chromosome 17, region q12. Recombinant Lkn-1 was a potent chemoattractant for neutrophils, monocytes, and lymphocytes and induced calcium flux in these cells. Lkn-1 specifically induced calcium flux in CCR1- and CCR3-expressing HOS cell lines. Lkn-1 suppressed colony formation by human granulocyte-macrophage, erythroid, and multipotential progenitor cells stimulated by combinations of growth factors. Hence, we have isolated and characterized a human C6 beta-chemokine that is a potent agonist at CCR1 and CCR3 and shows broad biologic activities, including leukocyte chemoattraction.  相似文献   
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A pattern sensitivity was observed in the threshold dose rate upset response of a bipolar 16 K PROM for radiation pulse widths of 20-100 ns. For the worst case pattern, the upset threshold was a factor of three lower than for the commonly used checkerboard pattern. The mechanism or this pattern sensitivity was found to be a capacitively coupled voltage transient on a sensitive node which caused a low-to-high transition at the output. A design fix was implemented to significantly alter the ratio of the two parasitic capacitances in a capacitive divider which reduced the amplitude of the voltage transient at the sensitive node. It was demonstrated that in the redesign, the pattern sensitivity was eliminated  相似文献   
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Language resources for studying doctor–patient interaction are rare, primarily due to the ethical issues related to recording real medical consultations. Rarer still are resources that involve more than one healthcare professional in consultation with a patient, despite many chronic conditions requiring multiple areas of expertise for effective treatment. In this paper, we present the design, construction and output of the Patient Consultation Corpus, a multimodal corpus of simulated consultations between a patient portrayed by an actor, and at least two healthcare professionals with different areas of expertise. As well as the transcribed text from each consultation, the corpus also contains audio and video where for each consultation: the audio consists of individual tracks for each participant, allowing for clear identification of speakers; the video consists of two framings for each participant—upper-body and face—allowing for close analysis of behaviours and gestures. Having presented the design and construction of the corpus, we then go on to briefly describe how the multi-modal nature of the corpus allows it to be analysed from several different perspectives.

  相似文献   
60.
Radiation effects testing, part selection, and hardness assurance for application to electronic components in the natural space environment are discussed. The emphasis is on semiconductor devices, primarily silicon microcircuits, which are used in the greatest quantity and which, in most cases, are the most sensitive. After a summary of the natural space radiation environment and the effects of radiation on semiconductor devices, laboratory simulation of space radiation and extrapolation to space are covered. Radiation testing is performed to understand failure mechanisms, to characterize the radiation response of specific devices, and to provide data for lot acceptance. Part selection and hardness assurance are discussed by contrasting the traditional approach with the unique aspects of space systems. Some recommendations are made for treating the more complex aspects of space system microcircuit hardness assurance  相似文献   
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