Effect of heat treatment on the microstructure and mechanical properties of spray-formed 7055 aluminium alloy

7055 Al alloys samples were prepared by spray forming and hot-extrusion followed by two different aging treatment procedures. Their different distributions of GP zones, and nanoscale precipitates η′ (MgZn) and η (MgZn₂) are extensively investigated by transmission electron microscope (TEM). The mechanical properties, including tensile strength, Vickers hardness and elongation of both aged 7055 Al alloys, have also been measured and analysed. It is found that T6 and T76 aging treatment results in quite different microstructure and mechanical properties. The outstanding performance of the 7055 Al alloys after T6 aging treatment is attributed to nanoscale semi-coherent dispersion precipitates.     

Bimodal Logics with Contingency and Accident

Contingency and accident are two important notions in philosophy and philosophical logic. Their meanings are so close that they are mixed up sometimes, in both daily life and academic research. This indicates that it is necessary to study them in a unified framework. However, there has been no logical research on them together. In this paper, we propose a language of a bimodal logic with these two concepts, investigate its model-theoretical properties such as expressivity and frame definability. We axiomatize this logic over various classes of frames, whose completeness proofs are shown with the help of a crucial schema. The interactions between contingency and accident can sharpen our understanding of both notions. Then we extend the logic to a dynamic case: public announcements. By finding the required reduction axioms, we obtain a complete axiomatization, which gives us a good application to Moore sentences.

     

道教存神养生与系统科学

道教存神养生作为道教养生术的一种,由于其中混杂了一些宗教成分,长期以来受到误解.本文认为,道教存神中的所谓"身神"是指信息,而存神经典中对于身神的描述则是在设计一种信息符号,存神实际上就是人们通过自己的精神活动向自身组织器官注入信息,使其负熵化的一种养生方式.     

Intrinsic frames of reference and egocentric viewpoints in scene recognition

Three experiments investigated the roles of intrinsic directions of a scene and observer's viewing direction in recognizing the scene. Participants learned the locations of seven objects along an intrinsic direction that was different from their viewing direction and then recognized spatial arrangements of three or six of these objects from different viewpoints. The results showed that triplets with two objects along the intrinsic direction (intrinsic triplets) were easier to recognize than triplets with two objects along the study viewing direction (non-intrinsic triplets), even when the intrinsic triplets were presented at a novel test viewpoint and the non-intrinsic triplets were presented at the familiar test viewpoint. The results also showed that configurations with the same three or six objects were easier to recognize at the familiar test viewpoint than other viewpoints. These results support and develop the model of spatial memory and navigation proposed by Mou, McNamara, Valiquette, and Rump [Mou, W., McNamara, T. P., Valiquiette C. M., & Rump, B. (2004). Allocentric and egocentric updating of spatial memories. Journal of Experimental Psychology: Learning, Memory, and Cognition, 30, 142-157].     

学习惰性研究综述

学习惰性是一种普遍存在的消极心理现象,它对学生和成人的学习造成负面影响.相关的研究国外已有而国内尚无.本研究为帮助学习者克服惰性、更好地学习和发展,在文献检索和典籍查阅的基础上,界定了惰性和学习惰性的概念;探讨了学习惰性的危害、成因及其影响因素;从认知、情绪、行为和易发人群等方面辨析了学习惰性与学习倦怠的异同;建议对学习惰性与学习倦怠采取不同的评估、教育和心理干预措施;最后对如何拓宽与深化学习惰性的研究进行了思考.     

智力落后学生句子判断能力的研究

以138名智力落后学生为被试,探讨了8-18岁学生的句子判断能力.结果显示:1)智力落后学生的句子判断能力随着年龄的增长而提高,在8-10岁到11-14岁之间增长显著,发展迅速;2)11-14岁组智力落后学生对于语法及语义错误的判断存在显著差异;3)句子判断能力相对较好的智力落后学生,因果关系复句与条件关系复句的判断成绩显著优于转折关系复句的判断成绩.     

班级朋友对抑郁的影响:一项社会网络分析

采用朋友提名和Beck抑郁问卷,以73个班级3034名大学生为被试,考察班级朋友网络中不同连接步数朋友的抑郁水平对个体抑郁的影响。结果发现:(1)互选朋友数量对抑郁存在显著的负向影响;(2)在控制了互选朋友数量的影响后,互选朋友中是否存在抑郁者,对个体自身的抑郁不具有显著的预测作用;(3)提名与被提名的直接朋友和两度距离朋友中,抑郁朋友数量对个体的抑郁具有显著的正向预测作用;(4)同性抑郁朋友的数量对个体的抑郁具有显著的正向预测作用,而异性抑郁朋友的数量对个体的抑郁则不具有显著的预测作用。综合上述结果可以得出以下结论:抑郁朋友在班级朋友网络中的影响范围仅限两度距离以内(包括两度),且这种影响不受朋友关系方向的限制。随着抑郁朋友的数量增多,个体抑郁的风险也显著增加,然而抑郁朋友对个体抑郁的影响,可能更多的是受到同性抑郁朋友的影响。     

"沙盘游戏"的理论分析及其在幼儿教育中的应用研究

受荣格积极想象技术及其理论的启发 ,吸收了威尔斯 (H .G .Wells)、玛格丽特·洛温菲尔德 (MargaretLowenfeld)等人有关儿童游戏理论与操作之精要 ,多拉·卡尔夫 (DoraKallf)在 2 0世纪 6 0年代初创设了“沙盘游戏”理论。沙盘游戏作为一种有效而独特的挖掘人类潜意识的技术 ,在国外的发展非常成熟 ,应用十分广泛 ;而国内缺乏对该理论的引介与探讨 ,我们结合正在广州育才幼儿园所做的个案研究 ,概要介绍沙盘游戏的理论与操作 ,进而探索“沙盘游戏”在幼儿园教育实践中的具体应用。     

自然事物认知偏好的初步实验研究

本研究从认知心理学角度采用实验方法探索自然科学学习的影响因素。发现：1自然事物的认知偏好中存在内隐学习现象。2．自然事物认知偏好的表现非常复杂：年龄的影响并不显著,经验的影响不可忽视;3．性别差异十分明显,男生比女生的自然事物认知偏好更为肯定更为积极,很可能社会性别角色是造成自然科学学习结果差异的重要原因;4．内隐组学习坦率好奇,倾向于把自然事物看得更熟悉更容易,具有更强的探究兴趣：外显组学生矜持审慎,倾向于把自然事物看得更陌生更难以理解,探究兴趣较弱。因此,科学教育要创设情境让学生潜移默化地学以致用;要帮助学生利用经验并从中获取乐趣、增长兴趣、树立志趣;要鼓励女孩子大胆挑战科学。     

非小细胞肺癌靶向治疗的前途与困惑

靶向治疗是运用抗肿瘤药物靶向性与肿瘤的不同特异性住点结合发生作用从而抑制肿瘤细胞生长的一种治疗手段。针对恶性肿瘤中的非小细胞肺癌,其在临床中取得了一定成效。然而,其中仍存在很多问题。本文针对吉非替尼在非小细胞肺癌中的运用,及其优点和所面临的问题,阐述如何应对完善靶向治疗的挑战。