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61.
Hugh S. Fairman 《Color research and application》1995,20(1):44-49
In 1993, the American Society for Testing and Materials carried out a field test of newly calculated tristimulus weighting factors. These weighting factors had been calculated by a method proposed by Venable. the test also included a method of correction for bandpass dependence put forth by Stearns. the purpose of the trial was to assess the possible reduction in bandpass dependence introduced by each of these sets of weights. A large number of sets of spectral data were gathered from the cooperators in the field test. Results of integration by the various sets of tristimulus weighting factors were calculated. A total of 15 120 color differences were calculated and statistics were derived to test the probable error resulting from each method of correction. Errors attributable to bandpass dependence were on the order of a few tenths to as much as one CIELAB unit when uncorrected weight sets were used. These errors could be reduced to a few hundreths of a CIELAB unit, and in some cases to a few thousandths of a unit, by employing one correcting strategy or the other. an overall mix of strategies was ultimately chosen to minimize the bandpass dependence over the entire range of weight sets. Utilizing this mixed strategy, the median error introduced into 10-nm integration by bandpass dependence was only 0.004 CIELAB units. © 1995 John Wiley & Sons, Inc. 相似文献
62.
涂层材料的断裂分析(英文) 总被引:1,自引:0,他引:1
和基体厚度相比,涂层很薄,因此细观力学模型可把基体作为半无限弹性体。由于涂层和基体材料的膨胀系数及弹性系数不匹配,涂层材料中残余热应力的解析解为 E_c/(1-γ_c)·(α_s-α_c)△T。用有限元法校核,该应力和解析解吻合得好。通过对涂层产生裂纹驱动力和断裂韧性的讨论,提出了抗裂涂层厚度公式。 相似文献
63.
64.
实证分析:上市公司资本结构的影响因素 总被引:13,自引:0,他引:13
在国内外相关研究的基础上,利用我国资本市场的公开数据,对上市公司资本结构的影响因素进行实证研究,得出了若干重要结论。 相似文献
65.
Thompson Karin E.; Malow Robert M.; Corrigan Sheila A.; Sorensen James L. 《Canadian Metallurgical Quarterly》1992,6(2):67
Drug users are particularly at risk for contracting the human immunodeficiency virus and serve as a major mechanism for spreading the virus to other sectors of the population. As a result drug abuse treatment and potential behavioral change strategies are primary public health issues. The purpose of this article is to review the contributions included in this special edition, which represent an effort to describe the most current thinking in the field with a blend of theoretical, review, and empirical articles. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
在对影响体育教学质量的几种环境因素分析的基础上,提出了克服体育实践教学环境 因素的消极影响的主要措施以及正确利用这些物理因素的积极作用。 相似文献
67.
68.
Burns John W.; Kubilus Amanda; Bruehl Stephen; Harden R. Norman; Lofland Kenneth 《Canadian Metallurgical Quarterly》2003,71(1):81
Changes in maladaptive cognitions may constitute therapeutic processes of multidisciplinary pain programs. A cross-lagged panel design was used to determine whether (a) early-treatment cognitive change predicted late-treatment outcome index change, but not vice versa; and (b) these effects remained significant with depression change controlled. Ninety chronic pain patients, in a 4-week multidisciplinary program, completed measures of catastrophizing, pain helplessness, depression, pain, interference, and activity level at pre-, mid-, and posttreatment. With depression changes controlled, early-treatment catastrophizing and pain helplessness changes predicted late-treatment outcome index changes, but not vice versa; early-treatment depression changes predicted late-treatment activity changes, but not vice versa. Findings advance understanding of pain treatment process and suggest that negative cognition changes may indeed affect improvements in treatment outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
Shaw Daniel S.; Gilliom Miles; Ingoldsby Erin M.; Nagin Daniel S. 《Canadian Metallurgical Quarterly》2003,39(2):189
The present study applied a semiparametric mixture model to a sample of 284 low-income boys to model developmental trajectories of overt conduct problems from ages 2 to 8. As in research on older children, 4 developmental trajectories were identified: a persistent problem trajectory, a high-level desister trajectory, a moderate-level desister trajectory, and a persistent low trajectory. Follow-up analyses indicated that initially high and low groups were differentiated in early childhood by high child fearlessness and elevated maternal depressive symptomatology. Persistent problem and high desister trajectories were differentiated by high child fearlessness and maternal rejecting parenting. The implications of the results for early intervention research are discussed, with an emphasis on the identification of at-risk parent-child dyads. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.
弱凝胶调驱降维数值模拟方法研究 总被引:1,自引:0,他引:1
目前用于弱凝胶调驱的化学驱软件大多存在计算速度慢、数值弥散现象严重的问题,为了提高弱凝胶调驱数值模拟的速度和精度,提出了降低维数的模拟方法。利用追踪流线的方法,将弱凝胶调驱的三维渗流问题,转化为沿流线计算饱和度的一维问题,大大降低了求解饱和度方程组中方程的数目,从而提高了计算速度。利用该方法,模拟了玉门老君庙油田一个试验井区的水驱开发历史,优化了弱凝胶调驱的注入浓度、注入速度及注入体积等参数,并预测了弱凝胶调驱的动态,预测该方案可提高采收率7.6%。 相似文献