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81.
《Canadian Metallurgical Quarterly》2001,37(6):847
This study used multinomial logistic regression to examine relationships between child-care experience (in the context of overall family functioning) and preschool attachment. Attachment behavior was assessed at 36 months with the Strange Situation, and A, B, C, and D attachment classifications were assigned using the MacArthur coding system. Maternal sensitivity was the strongest predictor of preschool attachment classification. With respect to child-care effects, as at 15 months, no child-care factors (quantity, quality, or type) predicted, in and of themselves, attachment security at 36 months. However, 1 of 3 interactions involving child care that were detected at 15 months reemerged at 36 months: When maternal sensitivity was low, more hours per week in care somewhat increased the risk of the insecure-ambivalent (C) classification. There was significant but modest stability of attachment classifications from 15 to 36 months, especially for children with A and C classifications. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
82.
83.
N. N. Pilyugin 《Combustion, Explosion, and Shock Waves》2005,41(3):295-302
This paper reports results from measurements of the electron concentration in wakes behind aluminum spherical models flying at velocities of 2–5 km/sec in air-xenon mixtures at a total pressure in the ballistic track of 20–100 torr. The heating of the models moving in the ballistic track and aluminum ablation from their surfaces were calculated. The rate constant of electron attachment to microparticles is found, and it is shown that it depends on the fraction of xenon in the mixture. The dependence of the coefficient of electron accommodation to the microparticle surface on the xenon concentration in the mixture is obtained and explained from a physical point of view.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 3, pp. 65–73, May–June, 2005. 相似文献
84.
针对立盘过滤机滤饼附液率较高的问题,主要从年心轴、分配头、扇形板及滤布选用等方面进行了深入探讨,分析了反吹风、进料分配器、滤液的排放方式等对立盘过滤机滤饼附液率的影响,提出了相应的改进措施。 相似文献
85.
Graves Franklynn C.; Wallen Kim; Maestripieri Dario 《Canadian Metallurgical Quarterly》2002,116(3):489
This study investigated the role of the endogenous opioid system in maternal and affiliative behavior of group-living rhesus macaque (Macaca mularta) mothers with a history of abusive parenting. 18 mothers received an injection of the opioid antagonist naltrexone or saline for 5 days per wk for the first 4 wks of the infant's life. After treatment, mother-infant pairs were focally observed. Naltrexone did not significantly affect infant abuse or other measures of maternal behavior. Naltrexone increased the amount of grooming received by mothers from other group members and reduced the mothers' rate of displacement activities such as scratching, yawning, and self-grooming. These results concur with previous primate studies in suggesting that opioids mediate the rewarding effects of receiving grooming and affect anxiety-related behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
Examined the relationships between adolescents' attachment, cognitive organization, and their perceptions of control and support in an academic mentoring relationship. 98 students involved in a volunteer mentoring program were interviewed using the Adult Attachment Interview (AAI). Perceptions of security and control in the mentor-student relationship and perceptions of the program effectiveness were also assessed at the end of the program and 4 mo later. Results show that both adolescents' dismissing and preoccupied strategies in the AAI were negatively associated with their interpersonal perceptions of the mentoring experience. Some of these relationships were moderated by the sex of the dyad (same-sex vs opposite-sex). These findings are discussed in light of theoretical postulates of attachment theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
介绍KYZ-B浮选柱捕收区基于"浮选柱元"理论的设计思路和基于该思路稳流栅板和分区板的结构特点。稳流栅板为锥形多孔板可强化浮选柱内气相弥散;分区板将捕收区分为若干个独立单元。通过CFD方法研究了引入分区板区及稳流栅板后各独立分区内的气液两相流的流动特征。仿真结果表明,分区内回旋流大幅减弱,柱塞流特征明显。稳流栅板对气相有导向作用,使气相在整个截面内均匀分散。基于"浮选柱元"理论设计的三种规格的KYZ-B型浮选柱在德兴铜矿工业应用取得了良好的选矿指标。 相似文献
88.
Cellulase was immobilized directly on methyl methacrylate‐glycidyl methacrylate copolymer (MMA‐co‐GMA) and methyl methacrylate‐2‐hydroxy ethyl methacrylate copolymer (MMA‐co‐HEMA) by covalent attachment and crosslinking methods. The properties of the immobilized cellulase were investigated and compared with those of the free one. For the assays carried out through crosslinking method at 25°C and pH 7, the retained activities were found to be 91.92% and 74.63%, respectively, for MMA‐co‐GMA and MMA‐co‐HEMA crosslinked with 0.1% of 1‐cyclohexyl‐3‐(2‐morpholino‐ethyl) carbodiimide metho‐p‐toluenesulfonate (CMCT), respectively. The immobilized cellulase had better stability and higher retained activities with respect to pH, temperature, and storage stability than the free one. In the repeated use experiments, the immobilized cellulase using (MMA‐co‐GMA)‐CMCT (0.1%) and (MMA‐co‐HEMA)‐CMCT (0.1%) did not change after 10 and eight times of repeated use and maintained 67% and 62% from their original activities after 25 times, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
89.
大功率白光LED封装技术对器件寿命的影响 总被引:1,自引:0,他引:1
通过功率LED器件封装工艺技术的改进来降低芯片结温,从而减缓器件光衰速率,延长其预期的工作寿命时间。对用于封装的关键原材料的选取进行了对比实验,指出了采用纳米级材料改进导热可降低热阻,论述了正确选用混胶材料和工艺,可以减缓器件光衰速率,达到在较高的环境温度条件下,器件使用寿命大于50 000 h。论述了器件芯片的结温对光、电、色性能的影响和不同结温其预期工作寿命时间也不同的关联性。 相似文献
90.
连接接头是飞机结构设计中不可缺少的连接件,用来实现不同构件间的连接、传递和载荷分配。在使用过程中,连接接头处容易产生应力集中,导致疲劳破坏。正确分析接头的整体受力特性以及应力分布特征是减小其应力集中的关键。本文根据某机型货舱门下部连接接头的结构特点及受力情况,用MSC.Patran软件进行有限元应力分析,结合全机的应力计算结果,获得货舱门下部梁A与梁B之间连接接头的应力分析边界条件,把边界条件施加于货舱门下部梁A与梁B之间连接接头的细节有限元模型中,计算各工况下所有单元的最大应力,确定该连接接头的危险部位。 相似文献