The development of a multidimensional scale to evaluate motor vehicle dynamic qualities

Advances in motor vehicle engineering will allow greater refinement of the dynamic qualities of passenger cars in the near future. This paper describes the development and initial validation of a reliable and valid multidimensional scale to assess these parameters based upon a technique previously developed to evaluate aircraft handling qualities. The scaling methodology developed emphasizes the interaction between the vehicle's dynamic behaviour and the category of vehicle (e.g. sports car, executive saloon). This three-part study describes the initial extraction and the subsequent verification of the scale dimensions from an analysis of the opinions of circa 500 drivers, followed by an evaluation of the sensitivity and diagnosticity of the scale to distinguish between the road behaviour exhibited by vehicle types. The results suggest that the scale shows both content and construct validity, being able to distinguish both between broad categories of vehicle and different models of vehicle within a particular category in a consistent and meaningful manner.     

"Detection of overreported psychopathology with the MMPI-2 RF validity scales": Correction to Sellbom and Bagby (2010).

Reports an error in "Detection of overreported psychopathology with the MMPI-2 RF form validity scales" by Martin Sellbom and R. Michael Bagby (Psychological Assessment, 2010[Dec], Vol 22[4], 757-767). There was an error in the title. The title should have read “Detection of Overreported Psychopathology With the MMPI-2-RF Validity Scales.” (The following abstract of the original article appeared in record 2010-24850-001.) We examined the utility of the validity scales on the recently released Minnesota Multiphasic Personality Inventory–2 Restructured Form (MMPI-2 RF; Ben-Porath & Tellegen, 2008) to detect overreported psychopathology. This set of validity scales includes a newly developed scale and revised versions of the original MMPI-2 validity scales. We used an analogue, experimental simulation in which MMPI-2 RF responses (derived from archived MMPI-2 protocols) of undergraduate students instructed to overreport psychopathology (in either a coached or noncoached condition) were compared with those of psychiatric inpatients who completed the MMPI-2 under standardized instructions. The MMPI-2 RF validity scale Infrequent Psychopathology Responses best differentiated the simulation groups from the sample of patients, regardless of experimental condition. No other validity scale added consistent incremental predictive utility to Infrequent Psychopathology Responses in distinguishing the simulation groups from the sample of patients. Classification accuracy statistics confirmed the recommended cut scores in the MMPI-2 RF manual (Ben-Porath & Tellegen, 2008). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

重型炮弹自动称重技术

为解决在称重中的冲击和重心位置问题,确保称重的精度,采用一种自动机构和防爆电子秤方法。介绍专机构成和工作流程,通过找到防爆电子秤的链接和选择,找到合适的防爆电子秤进行称重。结果表明,专机机械机构对弹体定位的保证和称重机构与秤体托盘直接相连,能保证称重的精度和称得的值的准确,达到生产检验精度要求,实现重型弹体自动上弹称重。目前该技术已投入使用,效果良好。     

Comparison of oxidation behaviours among three Fe–Cr based alloys for solid oxide fuel cell interconnect

Abstract

Two metallic alloys, containing comparable amounts of Cr, underwent oxidation in hot air simulating (the solid oxide fuel cell cathode atmosphere) for various periods. The results demonstrated that the oxidation kinetics of Crofer22 APU and equivalent ZMG232 followed the parabolic rate law and oxidation rates increased with temperature. Typical oxidation rates of Crofer22 APU and ZMG232 upon annealing treatment are approximately 0·21 orders of magnitude lower than that of ZMG232. An oxide scale electron probe microanalyser, a scanning electron microscope and X-ray diffractometer were adopted to verify the applicability of Fe–Cr based alloys in the solid oxide fuel cell interconnect component. Two alloys contain comparable amount of Cr, Mn and Fe, and their surface oxides as analysed are indicated to be Cr₂O₃ and (Mn,Fe)Cr₂O₄ spinel compound. In summary, Crofer22 APU had the best oxidation resistance of any of the alloys of interest.     

Analyzing developmental processes on an individual level using nonstationary time series modeling.

Individuals change over time, often in complex ways. Generally, studies of change over time have combined individuals into groups for analysis, which is inappropriate in most, if not all, studies of development. The authors explain how to identify appropriate levels of analysis (individual vs. group) and demonstrate how to estimate changes in developmental processes over time using a multivariate nonstationary time series model. They apply this model to describe the changing relationships between a biological son and father and a stepson and stepfather at the individual level. The authors also explain how to use an extended Kalman filter with iteration and smoothing estimator to capture how dynamics change over time. Finally, they suggest further applications of the multivariate nonstationary time series model and detail the next steps in the development of statistical models used to analyze individual-level data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

萨尔公司的皮带秤安装应用指南

皮带秤使用和安装过程中需要考虑的最重要问题是如何将皮带秤安装到皮带输送机上,而安装不正确是皮带秤性能差的主要原因。本文根据美国萨尔公司的皮带秤安装应用指南的资料,介绍了皮带秤的安装位置选择和安装要点。     

Effect of component thickness on lifetime and oxidation rate of chromia forming ferritic steels in low and high pO2 environments

Abstract

Long term oxidation tests were carried out with a high-Cr ferritic steel at 800°C and 900°C in simulated cathode and anode gas of a solid oxide fuel cell (air and an Ar/H₂/H₂O mixture respectively). It was found that with decreasing sample thickness the life time of the steel decreases due to breakaway phenomena. This effect is caused by faster exhaustion of the chromium reservoir from the bulk alloy in the case of thinner components. During air exposure the oxidation rates increase with decreasing specimen thickness and this has to be taken into account in the calculation of the Cr-reservoir exhaustion. This thickness dependence is not found during the exposures in simulated anode gas. Hence, especially for thin walled components, the oxidation rates in anode gas are substantially smaller and thus the life times are longer than during air exposure. The differences in oxidation behaviour in the two environments are discussed on the basis of scale formation mechanisms involving microcrack formation in the surface oxide scale and depletion of major and minor alloying additions in the bulk alloy.     

FLUCTUATION-FLIPPING ORBITS OF FREELY-DRAINING RIGID DUMBBELLS IN CONVERGING-DIVERGING PORE FLOWS

This paper addresses the deterministic translational-rotational motion of a freely-draining rigid dumbbell that is freely suspended in pressure-driven Stokes flow through a periodically corrugated pore or channel. As is demonstrated by numerical integration of the coupled, nonlinear equations of motion within a sinusoidally corrugated, axisymmetric pore, passage of the dumbbell through successive converging and diverging local flow environments engenders rotary fluctuations relative to the local streamlines that gradually increase in amplitude, over many pore wavelengths, until it eventually flips over. Then the dumbbell slowly realigns itself with the flow, with diminishing fluctuations-whereupon the whole cycle begins again.

To analyze the cumulative effect of zero-mean rotary fluctuations, we first consider a simpler problem in which a prolate body of zero axis ratio is subjected to externally applied, harmonic rotary oscillations while immersed in steady, homogeneous shear. Two-timescale asymptotics combined with inner-outer matching yield a leading-order formula for the orientational history that agrees very closely with the numerical solution for this case. In particular, the non-oscillatory (slow) component of the behavior is asymptotically equivalent to a Jeffery orbit described by a nonzero effective axis ratio.

Subsequently the hydrodynamic mechanism responsible for moving the dumbbell (of dimensionless length 2() out of alignment with the local streamlines is analyzed for a two-dimensional, periodically corrugated channel, with accounting for (i) the leading effect of spatial inhomogeneity of the flow field, and (ii) the first two corrections in (small) angle of misalignment. For sufficiently short times following the initial condition of perfect alignment with the flow, the trajectory of the dumbbell's midpoint is effectively decoupled from the orientational history. These approximations lead to a Riccati equation, for which the coefficients are periodic functions under a subtle assumption involving the flow field. A two-scale analysis then explains the numerically observed ord ((^?;) scaling of the distance traveled between successive flips. Motivation for the required assumption, and approximations of the hydrodynamic coefficients, are obtained from lubrication theory. When a sinusoidally corrugated, two-dimensional channel is chosen to match the meridian-plane generator of the axisymmetric pore, the asymptotic orientational history for the former and the numerical solution for the latter are found to appear remarkably similar.

Our analysis is placed in context with regard to Lagrangian unsteadiness and the general dynamical-systems theory advanced in a series of papers by A. J. Szeri, S. Wiggins, W. J. Milliken and/or L. G. Leal [J. Fluid Mech., 228,207-241 (1991); 237, 33-56 (1992); 250, 143-167 (1993)] for microstructure in “complex” flows. The orientational dynamics considered here have important implications for deterministic cross-stream migration of elastic dumbbells [Nitsche, L. C, AIChE J., 42, 613-622 (1996)].     

北京农村地区合院式传统民居院落布局模拟分析

基于2012年10月～2013年6月期间对20世纪90年代以前的北京农村地区传统民居的现场调研,汇总了北京农村地区合院式传统民居的院落形式和空间尺度,给出了几种典型院落模型,并应用Airpak和Ecotect等软件对其院落风环境和日照进行模拟分析,对传统民居相关传承因素赋予了科学化解释,为合院式传统民居的改良设计提供参考.