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1.
Nitrogen addition to iron powder by mechanical alloying 总被引:3,自引:0,他引:3
Nitrogen was alloyed into iron (a) by mechanical processing in a nitrogen gas environment, and (b) by mechanically alloying with iron-nitride powders to characterize resulting nano-structure and nitrogen distribution. Although the infused nitrogen concentration was significantly greater than the thermodynamic equilibrium solubility of iron, no nitrides formed, even for nitrogen concentrations as high as 4.1 wt.% However, a bctFe phase did form. Lattice expansion calculations indicate that the sum of the interstitial bcc-Fe and bctFe nitrogen concentrations was significantly less than the total measured nitrogen concentration. A considerable portion of the mechanically infused nitrogen was determined to be associated with nanograin boundaries. 相似文献
2.
The rat's willingness to ingest glucose after an initial intraoral intake test was probed by beginning a 2nd intraoral intake test at variable durations (1–220 min). In Exp 1, after an initial meal of 12.5% glucose solution averaging 26.9?±?1.7 ml, the size of the 2nd (probe) meal of the same stimulus increased linearly from 4.0?±?0.9 ml after a 1-min delay to 15.4?±?2.7 ml after a 120-min delay. In Exp 2, intraoral intake of a more concentrated (37.5%) glucose solution rose more slowly as a function of delay from 2.4?±?2.7 ml to 4.9?±?0.6 ml. For each glucose concentration, the linear recovery function and a slope that depends on stimulus concentration are consistent with a role for gastric emptying during the delay in intake recovery. In Exp 3, rats ingested 12.5% or 37.5% glucose to satiety in an initial test and received, after a variable delay, either the same or the other concentration as the probe stimulus. The same volumes were ingested at each delay whether the glucose concentration of the probe stimulus was the same or was switched from that presented in the initial test. This result shows that the taste and caloric properties of the probe stimulus played no role in determining how much of it would be ingested… (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Examined features of an intergroup context that can affect people's preferred responses to a situation of social injustice. 90 undergraduates were randomly assigned to 1 of 3 conditions of group permeability (open, token, or closed) and 1 of 2 conditions of social identity salience (not salient or salient). It was predicted on the basis of social identity theory that individualistic responses would be preferred to a collective response when group boundaries were more open but not when they were closed. It was also expected that under conditions of group impermeability, collective behavior would be preferred to a greater extent by individuals for whom social identity was salient than by individuals for whom it was not salient. The results, which generally supported these hypotheses, are discussed in terms of social psychological theories of intergroup relations and also with regard to their potential practical implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
Glasgow's revival of the "imagery debate" in computational terms provides a renewed opportunity to review the role of logical reasoning in general problem solving. Of special interest is the long-standing distinction between analogical or depictive problem representations, and the more abstract linguistic forms typified by traditional formal logic syntax.
In our brief statement, we recall that logical reasoning rests on semantics not syntax, and that the concepts of soundness, completeness, and consistency are manifest in both depictive and linguistic representations. We emerge with two conclusions: (1) enduring confusion regarding computational aspects of the "imagery debate" arise from long-standing confusion regarding key logical concepts, and related notions such as epistemological versus heuristic adequacy, logical versus probabilistic independence, and direct versus indirect representations; (2) the desire for depictive reasoning methods is ultimately motivated by human needs, not computational needs. 相似文献
In our brief statement, we recall that logical reasoning rests on semantics not syntax, and that the concepts of soundness, completeness, and consistency are manifest in both depictive and linguistic representations. We emerge with two conclusions: (1) enduring confusion regarding computational aspects of the "imagery debate" arise from long-standing confusion regarding key logical concepts, and related notions such as epistemological versus heuristic adequacy, logical versus probabilistic independence, and direct versus indirect representations; (2) the desire for depictive reasoning methods is ultimately motivated by human needs, not computational needs. 相似文献
5.
Object-oriented design is an approach to systems development that proposes the use of system objects to build new systems and rebuild old ones. An important goal of object-oriented development is to change the nature of traditional software development from designing and writing models from scratch to building systems through the assembly of reusable software objects. This article discusses the productivity potential as well as the limitations of object-oriented systems development and makes recommendations for its use. 相似文献
6.
Randy L. Hackbarth Audris Mockus John Douglas Palframan David M. Weiss 《Empirical Software Engineering》2010,15(3):219-249
To be relevant to the goals of an enterprise, an industrial software engineering research organization must identify problems
of interest to, and find solutions that have an impact on, the software development organizations within the company. Using
a systematic measurement program both to identify the problems and assess the impact of solutions is key to satisfying this
need. Avaya has had such a program in place for about seven years. Every year we produce an annual report known as the State
of Software in Avaya that describes software development trends throughout the company and that contains prioritized recommendations
for improving Avaya’s software development capabilities. We start by identifying the goals of the enterprise and use the goal-question-metric
approach to identify the measures to compute. The result is insight into the enterprise’s problems in software development,
recommendations for improving the development process, and problems that require research to solve. We will illustrate the
process with examples from the Software Technology Research Department in Avaya Labs whose purpose is to improve the state
of software development and know it. “Know it” means that improvement should be subjectively evident and objectively quantifiable.
“Know it” also means that one must be skilled at identifying the data sources, performing the appropriate analyses to answer
the questions of interest, and validating that the data are accurate and appropriate for the purpose. Examples will include
how and why we developed a measure of software quality that appeals to customers, how and why we are studying the effectiveness
of distributed software development, and how and why we are helping development organizations to adopt iterative development
methods. We will also discuss how we keep the company and the department apprised of the current strengths and weaknesses
of software development in Avaya through the publication of the annual State of Software in Avaya Report. Our purpose is both
to provide a model for assessment that others may emulate, based on seven years of experience, and to spotlight analyses and
conclusions that we feel are common to software development today. 相似文献
7.
Validity of the emotional Stroop task hinges on equivalence between the emotion and the control words in terms of lexical features related to word recognition. The authors evaluated the lexical features of 1,033 words used in 32 published emotional Stroop studies. Emotion words were significantly lower in frequency of use, longer in length, and had smaller orthographic neighborhoods than words used as controls. These lexical features contribute to slower word recognition and hence are likely to contribute to delayed latencies in color naming. The often-replicated slowdown in color naming of emotion words may be due, in part, to lexical differences between the emotion and control words used in the majority of such studies to date. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
This paper presents a vision-based collision avoidance technique for small and miniature air vehicles (MAVs) using local-level frame mapping and path planning. Using computer vision algorithms, a depth map that represents the range and bearing to obstacles is obtained. Based on the depth map, we estimate the range, azimuth to, and height of obstacles using an extended Kalman filter that takes into account the correlations between obstacles. We then construct maps in the local-level frame using cylindrical coordinates for three dimensional path planning and plan Dubins paths using the rapidly-exploring random tree algorithm. The behavior of our approach is analyzed and the characteristics of the environments where the local path planning technique guarantees collision-free paths and maneuvers the MAV to a specific goal region are described. Numerical results show the proposed technique is successful in solving path planning and multiple obstacle avoidance problems for fixed wing MAVs. 相似文献
9.
10.
Dowdy Erin; Twyford Jennifer M.; Chin Jenna K.; DiStefano Christine A.; Kamphaus Randy W.; Mays Kristen L. 《Canadian Metallurgical Quarterly》2011,23(2):387
Reports an error in Factor structure of the BASC–2 Behavioral and Emotional Screening System Student Form by E. Dowdy, et al. (Psychological Assessment. np). There was an omission in the author note. The author note should have included a disclosure as follows, “Randy W. Kamphaus wishes to disclose a potential conflict of interest in that he receives a portion of royalties on net sales of BESS.” (The following abstract of the original article appeared in record 2011-04578-001.) The BASC–2 Behavioral and Emotional Screening System (BESS) Student Form (Kamphaus & Reynolds, 2007) is a recently developed youth self-report rating scale designed to identify students at risk for behavioral and emotional problems. The BESS Student Form was derived from the Behavior Assessment System for Children—Second Edition Self-Report of Personality (BASC–2 SRP; Reynolds & Kamphaus, 2004) using principal component analytic procedures and theoretical considerations. Using 3 samples, the authors conducted exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) to understand the underlying factor structure of the BESS Student Form. The results of the EFA suggested that the SRP contained a 4-factor (i.e., Personal Adjustment, Inattention/Hyperactivity, Internalizing, School Problems) emergent structure, which was supported by CFA in 2 additional samples. Practical and research implications are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献