跨通道情境下双任务范式与计时中断范式中的效应比较*

为了探讨跨通道情境下同一种刺激序列中双任务范式与计时中断范式中位置效应和间断效应的异同,研究设计了实验1和实验2。实验1以2500 ms和4500 ms为目标时距,采用相同的刺激序列(视觉呈现时距信号,听觉呈现干扰信号或中断信号),要求3组被试分别在控制、干扰及中断条件下完成相应任务,结果发现不管2500 ms或4500 ms时,中断条件较干扰条件和控制条件的间断效应更明显;同时发现在2500 ms时,不管控制、干扰还是中断条件下均发现了位置效应,而4500 ms时仅在中断条件下出现了位置效应,这可能由于实验1的控制及干扰任务中的4500 ms时的“晚”位置的时间确定性较高,以致掩盖了位置效应。为了降低“晚”位置出现的确定性,更好地对比两种范式中的效应,实验2将目标时距设置为1500 ms和2500 ms,结果发现在1500 ms或2500 ms时,不管控制、干扰还是中断条件下均发现了位置效应,且中断条件较干扰条件和控制条件下间断效应更明显。上述结果意味着跨通道情境下同一种刺激序列中双任务范式与计时中断范式中位置效应是否相同局限在一定时间范畴;计时中断范式中的中断效应对计时的消弱较双任务范式干扰效应更显著。     

TEM study of defects generated in 4H-SiC by microindentations on the prismatic plane

The deformation microstructure of single crystals of 4H-SiC resulting from microindentations on a prismatic surface was investigated by TEM. Indentations were performed at 400 and 675°C, i.e. below the brittle to ductile transition temperature of 4H-SiC (temperature close to 1100°C). TEM analysis reveals dissociated dislocations as well as extended stacking faults in the basal plane. In addition, perfect edge dislocations are observed on prismatic planes. From the observations, it is assumed that perfect dislocations are nucleated in the prismatic plane and cross-slip on the basal one where they dissociate.     

肿瘤干细胞分离方法研究现状

肿瘤干细胞理论能够解释肿瘤的发生、发展和转移等生物学行为,使人们对恶性肿瘤有一个全新的认识,为临床治疗展现全新视角,使肿瘤靶向治疗找到了新靶点,改变目前药物针对全部癌细胞的治疗策略。本文就肿瘤干细胞分离方法做一简要综述。     

The Expansion and Restructuring of Intellectual Property and Its Implications for the Developing World

In this paper we begin with a reference to the work of Hernando de Soto The Mystery of Capital: Why Capitalism Triumphs in the West and Fails Everywhere Else, and his characterization of the Western institution of formal property . We note the linkages that he sees between the institution and successful capitalist enterprise. Therefore, given the appropriateness of his analysis, it would appear to be worthwhile for developing and less developed countries to adjust their systems of ownership to conform more closely to the Western system of formal property. However, we go on to point out that property relationships within the Western system have become subject to redefinition through the expansion of Intellectual Property (IP) rights in ways that ultimately work to the disadvantage of the developing and less developed countries. We point out that this restructuring has been given global application through the implementation of the TRIPS agreement by the WTO. In the final section of the paper I suggest ways in which IP rights and relevant institutions can be reformed in order to avoid the disadvantages to the developing and less developed countries.

Circle graphs and monadic second-order logic

This article is part of a project consisting in expressing, whenever possible, graph properties and graph transformations in monadic second-order logic or in its extensions using modulo p cardinality set predicates or auxiliary linear orders. A circle graph is the intersection graph of a set of chords of a circle. Such a set is called a chord diagram. It can also be described by a word with two occurrences of each letter, called a double occurrence word. If a circle graph is prime for the split (or join) decomposition defined by Cunnigham, it has a unique representation by a chord diagram, and this diagram can be defined by monadic second-order formulas with the even cardinality set predicate. By using the (canonical) split decomposition of a circle graph, we define in monadic second-order logic with auxiliary linear orders all its chord diagrams. This construction uses the fact that the canonical split decomposition of a graph can be constructed in monadic second-order logic with help of an arbitrary linear order. We prove that the order of first occurrences of the letters in a double occurrence word w that represents a connected circle graph determines this word in a unique way. The word w can be defined by a monadic second-order formula from the word of first occurrences of letters. We also prove that a set of circle graphs has bounded clique-width if and only if all the associated chord diagrams have bounded tree-width.     

短时距标量计时模型的建构研究

采用预期式研究范式,创造性地使用单任务研究程序,从心理物理学的视角,通过六个实验系统地考查了影响被试短时距(6s至24s)估计的标量特性和物理、心理和生理的信息源因素.深入探讨了注意、激活、间断和间断期望效应因素对时间估计行为的影响及时序信息的动态加工过程.在此基础上,包含时钟、累加、记忆和比较四个动态加工过程的短时距标量计时模型得以建构.     

Plato the Democrat？ Some Thoughts on the Politics of the Laws

In the Laws （which Plato calls his ＂second-best society＂） Plato asserts that the best attainable form of society will combine the better features of autocracy and democracy. The democracy will be one where aidos （＂respect＂） will be a prominent feature, as will be the rule of laws underpinned by the belief that God, not man, is the measure of all things. Unlike in the Republic, the accumulation of wealth and property will be the right of all citizens, including rulers. But it will operate under strict limits： a maximum of four quanta of property will be allowed by any citizen, while a minimum of one （which will provide a good life though perhaps not a rich one） will be guaranteed. The affinity of such a view with that of John Rawls is striking. The article ends with a brief interview between the reader and Plato, in which some of the above issues are discussed.     

道德的法律强制探析

由于存在着道德仅靠自身力量所无法解决的问题 ,而这些问题因其对社会秩序和社会生活的重要性又必须获得解决 ,使得道德的法律强制成为必要。多元背景下道德共识的存在 ,道德与法律共同的问题域以及现代社会的立法民主化机制 ,为道德的法律强制提供了可能。道德法律强制的合理性 ,只有通过对于应当予以法律强制的道德的性质、可强制的道德的范围以及道德法律强制的立法和司法程序的学理分析 ,方可予以证成。     

Algebraic Aspects of Cut Elimination

We will give here a purely algebraic proof of the cut elimination theorem for various sequent systems. Our basic idea is to introduce mathematical structures, called Gentzen structures, for a given sequent system without cut, and then to show the completeness of the sequent system without cut with respect to the class of algebras for the sequent system with cut, by using the quasi-completion of these Gentzen structures. It is shown that the quasi-completion is a generalization of the MacNeille completion. Moreover, the finite model property is obtained for many cases, by modifying our completeness proof. This is an algebraic presentation of the proof of the finite model property discussed by Lafont [12] and Okada-Terui [17].     

大脑两半球与整体和局部性质的选择性加工

研究大脑两半球在加工整体和局部性质中的优势以及两半球能否同时分别选择两个复合刺激的整体和局部性质。实验中把一个复合字母随机呈现在左视野或右视野,或者把两个复合字母同时分别呈现在左视野和右视野。实验一发现,在单侧呈现条件下,被试检测左右视野的整体或局部靶目标的反应时没有显著差别,但在双侧同时呈现条件下,检测右视野局部靶目标比检测左视野局部靶目标时的反应时短。实验二要求被试检测同时呈现在左右视野的整体或局部靶目标,发现当两个视野的靶目标处于同一水平时(整体或局部)反应时较短,两个视野的靶目标处于不同水平时(一侧处于整体水平而另一侧处于局部水平)反应时较长。这些结果提示,当两个复合刺激同时呈现在左右视野时,大脑左半球在选择性加工局部性质时具有优势;左右两半球更容易选择两个复合刺激同一个水平的性质,分别选择两个复合刺激不同水平的性质比较困难。