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排序方式: 共有5027条查询结果,搜索用时 390 毫秒
41.
Bruce P. Johnston John M. Sullivan Andrew Kwasnik 《International journal for numerical methods in engineering》1991,31(1):67-84
A method is presented for the fully automatic conversion of a general finite element mesh containing triangular elements into a mesh composed of exclusively quadrilateral elements. The initial mesh may be constructed of entirely triangular elements or may consist of a mixture of triangular and quadrilateral elements. The technique used employs heuristic procedures and criteria to selectively combine adjacent triangular elements into quadrilaterals based on preestablished criteria for element quality. Additional procedures are included to eliminate isolated triangles. The methods operates completely without user intervention once the nodal co-ordinates and element connectivity of the original mesh are supplied. 相似文献
42.
43.
Judge Timothy A.; Jackson Christine L.; Shaw John C.; Scott Brent A.; Rich Bruce L. 《Canadian Metallurgical Quarterly》2007,92(1):107
The present study estimated the unique contribution of self-efficacy to work-related performance controlling for personality (the Big 5 traits), intelligence or general mental ability, and job or task experience. Results, based on a meta-analysis of the relevant literatures, revealed that overall, across all studies and moderator conditions, the contribution of self-efficacy relative to purportedly more distal variables is relatively small. Within moderator categories, there were several cases in which self-efficacy made unique contributions to work-related performance. For example, self-efficacy predicted performance in jobs or tasks of low complexity but not those of medium or high complexity, and self-efficacy predicted performance for task but not job performance. Overall, results suggest that the predictive validity of self-efficacy is attenuated in the presence of individual differences, though this attenuation does depend on the context. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
44.
非洲油气勘探区战略选择建议 总被引:8,自引:5,他引:3
非洲不同类型的沉积盆地主要可归纳为:古、中生代挠曲盆地,中、新生代大陆边缘断陷盆地,板内裂谷盆地和大陆边缘进积三角洲盆地。通过盆地油气成藏条件地质综合评价、不同勘探阶段的类比和最终勘探潜力分析,对非洲的沉积盆地进行了划分,在此基础上,总结出非洲油气勘探区选择应遵循的原则。对于油气勘探长期战略选区,原则上,优选低成本油气远景区,即使存在高风险,但亦可获得高回报;对于油气勘探中期发展策略选区,应该寻找地质条件好的油气资源区,投资中短期高利润项目;对于油气勘探中短期发展策略选区,一般应优选中低成本、低风险、低利润且短期能获得油气发现和勘探突破的有利油气勘探区。图1表3参5 相似文献
45.
Braver Sanford L.; Wolchik Sharlene A.; Sandler Irwin N.; Sheets Virgil L.; Fogas Bruce; Bay R. Curtis 《Canadian Metallurgical Quarterly》1993,7(1):9
Reports the results of a 3-wave longitudinal study of a sizable, regionally representative sample of both noncustodial and custodial parents interviewed initially before their divorce was final. A model was tested that predicted the noncustodial parent's postdivorce contact with the child and the payment of child support from a series of factors related to a social exchange orientation. This orientation highlights the noncustodial parent's implicit calculation of the rewards vs the costs of continuing involvement and support of the child. It was found that noninvolvement was, in general, well-predicted, both cross-sectionally and longitudinally, by the model. The most powerful factor in the model was the noncustodial parent's perception that he or she had some control over the child's upbringing. Among fully employed noncustodial parents who reported high perceived control, there was an excellent record of involvement and child support payment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
46.
M.R.X. de Barros G. Nykolak D.J. DiGiovanni A. Bruce W.H. Grodkiewicz P.C. Becker 《Photonics Technology Letters, IEEE》1996,8(6):761-763
We report the gain, noise figure, output saturation power, and conversion efficiency of a highly concentrated Er/sup 3+/-doped alumino silicate fiber amplifier. We obtain a gain per unit length of 1.0 dB/cm, which corresponds to the highest gain per unit length obtained in an Er/sup 3+/-doped fiber amplifier. The pump power threshold ranges from 2 to 5 mW, depending on the fiber length. 相似文献
47.
Given integers m and n, we study the probability that structures of size n have all components of size at most m. The results
are given in term of a generalized Dickman function of n/m. 相似文献
48.
LONG TERM STORAGE STABILITY OF MIDDLE DISTILLATE FUELS FROM A CHEMICAL MECHANISTIC POINT OF VIEW. PART 2. 总被引:1,自引:0,他引:1
Bruce Beaver 《Petroleum Science and Technology》1992,10(1):1-37
The objective of this review is to (i) articulate the current level of understanding of the types of “reactive molecules” intimately involved in the long term oxidative storage instability of middle distillates, (11) review the types of chemical reaction mechanisms most likely involved in the “oxidative phase” of insoluble formation, (iii) review the postulated chemical mechanisms of stabilizer (additive) operation, and (iv) discuss future research areas that must be explored if a greater understanding and control of middle distillate instability is to be realized. 相似文献
49.
Avants S. Kelly; Margolin Arthur; Kosten Thomas R.; Rounsaville Bruce J.; Schottenfeld Richard S. 《Canadian Metallurgical Quarterly》1998,66(6):924
In response to a need to match drug users to the most appropriate and cost-effective level of care, it was hypothesized that socially anxious methadone-maintained patients would attain greater benefit from coping skills training provided in the context of a low-intensity enhanced standard methadone maintenance intervention (E-STD) than in the context of a high-intensity, socially demanding day treatment program (DTP). Social anxiety was assessed in 307 methadone-maintained patients using the Social Anxiety and Distress Scale prior to randomization to either E-STD or DTP. The hypothesis was supported: Socially anxious patients were drug free longer during treatment, were more likely to be abstinent at treatment completion, and had greater reductions in HIV risk behaviors if assigned to the lower intensity intervention, which was provided at ? the cost of the DTP. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
Philippe Meunier Robert Bruce Findler Paul Steckler Mitchell Wand 《Higher-Order and Symbolic Computation》2005,18(3-4):245-269
A set-based program analysis establishes constraints between sets of abstract values for all expressions in a program. Solving
the system of constraints produces a conservative approximation to the program's runtime flow of values.
Some practical set-based analyses use explicit selectors to extract the relevant values from an approximation set. For example,
if the analysis needs to determine the possible return values of a procedure, it uses the appropriate selector to extract
the relevant component from the abstract representation of the procedure.
In this paper, we show that this selector-based approach complicates the constraint solving phase of the analysis too much
and thus fails to scale up to realistic programming languages. We demonstrate this claim with a full-fledged value flow analysis
for case-lambda, a multi-branched version of lambda. We show how both the theoretical underpinnings and the practical implementation become
too complex. In response, we present a variant of set-based closure analysis that computes equivalent results in a much more
efficient manner. 相似文献