Is Scanning Electron Microscopy/Energy Dispersive X‐ray Spectrometry (SEM/EDS) Quantitative?

Scanning electron microscopy/energy dispersive X‐ray spectrometry (SEM/EDS) is a widely applied elemental microanalysis method capable of identifying and quantifying all elements in the periodic table except H, He, and Li. By following the “k‐ratio” (unknown/standard) measurement protocol development for electron‐excited wavelength dispersive spectrometry (WDS), SEM/EDS can achieve accuracy and precision equivalent to WDS and at substantially lower electron dose, even when severe X‐ray peak overlaps occur, provided sufficient counts are recorded. Achieving this level of performance is now much more practical with the advent of the high‐throughput silicon drift detector energy dispersive X‐ray spectrometer (SDD‐EDS). However, three measurement issues continue to diminish the impact of SEM/EDS: (1) In the qualitative analysis (i.e., element identification) that must precede quantitative analysis, at least some current and many legacy software systems are vulnerable to occasional misidentification of major constituent peaks, with the frequency of misidentifications rising significantly for minor and trace constituents. (2) The use of standardless analysis, which is subject to much broader systematic errors, leads to quantitative results that, while useful, do not have sufficient accuracy to solve critical problems, e.g. determining the formula of a compound. (3) EDS spectrometers have such a large volume of acceptance that apparently credible spectra can be obtained from specimens with complex topography that introduce uncontrolled geometric factors that modify X‐ray generation and propagation, resulting in very large systematic errors, often a factor of ten or more. SCANNING 35: 141‐168, 2013. ¹ Published 2012 Wiley Periodicals, Inc.     

Identification of indurated siltstone layers in advance of oil sands mining

Abstract

Indurated siltstone layers within both overburden and oil sands adversely affect rock handling productivity and maintenance at the Suncor mine. Drill performance monitoring and borehole geophysics have been used in the past to locate and characterize these hard layers at Suncor. The capabilities of both analog-and digital-based drill monitoring systems for the characterization of rock hardness are reviewed with reference to, Suncor and other mine studies. Particular reference is given to the alternative drilling-derived parameters to identify such zones and focuses on current studies at Suncor. This work relates to the development of diggability criteria and the subsequent ability to generate depth contour and thickness isopach plans for difficult bucket wheel and shovel digging conditions for mine planning.     

宝钢1580工作辊热变形的数值模拟与实验研究

根据现场的复杂工况，将轧辊辊身分为辊颈、辊端、辊肩、轧制区和非轧制区，综合考虑分段冷却、支撑辊、摩擦热和变形热等因素的影响，建立符合实际的边界条件，并根据热平衡原理建立了工作辊温度场数学模型。在宝钢1580热轧机上进行实验，详细分析了热凸度的瞬态变化以及热凸度在每块带钢轧制前后的变化，对热凸度间断的原因进行了分析，模型计算值和实测值吻合较好，表明模型工程实用性较强，为轧辊热变形的在线预报和控制提供了一定的依据。     

Modeling the principle physical parameters of graphite carbon foam

Graphite carbon foam, a mesophase, pitch-based material, portrays highly ordered topology structures which exhibit superior mechanical and thermal properties. Typical graphite carbon foam with dimensions 5 cm³, can have a surface area greater than 11 m², making it an excellent candidate for heat transfer applications. Accurate three dimensional modeling of carbon foams is necessary to study and predict their properties in simulation. This paper describes a computer algorithm for modeling POCO Foam® and similar carbon foams. The algorithm, written in MATLAB, captures the principle physical parameters of the carbon foam including bubble and pore diameter ranges and overall foam void percentage while retaining the random dispersal of spherical bubbles found in manufactured foams.     

Influence of client characteristics on initial counselor perceptions.

Analyzed the reactions of 30 professionally employed counselors to a role-played, videotaped intake interview with a potential client by a counselor who was not in view. The Ss assessed the probability that they would elect to counsel the person. They also rated both themselves and the client on A. Barak and M. LaCrosse's (1975) Counselor Rating Form (CRF). Results indicate that the trustworthiness dimension seemed to incorporate those characteristics that most influence initial counselor perceptions. It is suggested that the CRF can be used to obtain counselor as well as client perceptions and that the use of relativistic measures of attributes, that is, the use of scores that reflect the differences between one's own attributes and those of the other, may be a valuable methodological addition to research that uses the CRF. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

2004年世界电子业——快乐日子又来了!

2003年:半导体业重返好时光 　　iSuppli公司预计,2003年世界半导体市场销售将增长13.9%,与2002年的增长1.6%不可同日而语.……     

Sexual bias in the WAIS.

The WAIS protocols of 50 male and 50 female college students were analyzed for differential subtest performance. Although no significant differences were found for education, age, or Verbal, Performance, or Full Scale IQ, males were found to be highly superior on the Information, Arithmetic, Block Design, and Picture Arrangement subtests. Females were markedly superior on the Digit Symbol subtest. Wechsler's M-F score was calculated for each group and was found to differentiate the sexes better than any single subtest. The results suggest the presence of sexual bias in the WAIS even when age, education, IQ, and experience are held fairly constant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electromagnetism and quantum theory

Devices dependent upon such results of quantization as plasmas, semiconduction, or individual energy-level transitions now occupy a diverse and important position within the broad scope of electrical engineering. Their further development requires a thorough understanding of quantum theory on the part of device research and development engineers. To meet this need, many departments of electrical engineering may soon find it necessary to offer their own courses in quantum theory, just as they did in electromagnetic field theory after World War II.