7自由度机器人的图谱问题

本文在分析、归纳、综合的基础上作出了7自由度机械臂的图谱.包括位置空间、奇异空间、回避障碍和回避奇异等问题.给出了一种普遍适用的方法.并介绍了该方法的使用,对7自由度机器人的结构设计和选型有一定的参考价值.

7.0Ma以来中国黄土粉尘源区的化学风化历史研究-Sr同位素比值的证据

To investigate the changes in the chemical weathering intensity of dust source region in Asia continent, ~(87)Sr/~(86)Sr ratios of acid-washed residues from the loess deposits in China and Tajikistan were analyzed, respectively. The results and conclusions are listed as below. 1. The oscillation of ~(87)Sr/~(86)Sr ratios of acid-insoluble residues in the Chinese Loess Plateau was mainly attributed to the chemical weathering intensity of the source region and the grain size. Counteracted the effect of particle size, the calibrated 87Sr/S6Sr ratio can be used as a proxy for the chemical weathering intensity of the source region. 2. The Sr/ Sr ratios of red clay-loess sequence from the Loess Plateau indicate that the chemical weathering intensity of the dust source region between 7.0 and 2.6 Ma is stronger than that in the Quaternary period. This also suggests a general decline in chemical weathering intensity of the source region from 2.6 Ma to the present. Such pattern is more remarkable since 1.0 Ma BP. 3. The ~(87)Sr/~(86)Sr ratios of the Tajik loess during 0.8-1.8 Ma is much more higher than those from 0.8 Ma to the present. This implies that the chemical weathering intensity of the source region in Central Asia is much stronger during 0.8-1.8 Ma than the period since 0.8 Ma. 4. The record of Sr isotope ratios from both sections shows an accelerating course of aridity of the Asian dust source region over the Quaternary period.

0.7～1.8 GPa,室温～1120℃条件下α-β石英相变的弹性参数

为了解高温高压条件下,α-β石英相变过程中的弹性性质,在0.7～1.8GPa,室温～1120℃条件下,利用多顶砧波速测量装置,采用脉冲反射-透射法,测量了α石英以及相变为β石英的纵波速度,弹性纵波穿过单晶α石英的方向为平行结晶轴X方向。实验结果表明,随温度升高,α石英的纵波速度开始非线性降低,之后,快速升高,这一现象是由于α-β石英相变引起的,依据晶体对称性与弹性参数的关系确定了α石英的弹性参数(C_(11)),及其随温度和压力的变化关系,同时获得了β石英的弹性参数(C_(11)),实验证实,测量α-β石英相变时的纵波速度,不仅是确定α-β石英相变温度和压力的一种方法,也是校正高压腔体温度和压力的有力手段.

从看图讲故事看4-7岁儿童创造力的发展及其入学突降现象

创造力发展的年龄特征一直是研究者非常关注的问题。很多研究者认为，只有更全面地探查儿童创造力的发展，才能充分了解创造力的本质，所以，应该在多个领域中研究创造力。本研究以文学领域中儿童比较熟悉并喜欢的讲故事的形式，采用同感评估技术（CAT），对4-7岁儿童的创造力发展趋势进行了研究，并深入探讨了经常被人们提到的出现在该阶段中的“入学突降”现象。研究共分为两个部分：研究一考察了4-7岁儿童创造力的发展趋势和创造力的“入学突降”现象；研究二探查了讲故事任务的创造力与言语能力的关系，讨论了创造力的领域特殊性。研究结果发现： 1. 4-7岁儿童的创造力随年龄的增长总体上表现出先上升后下降的趋势，并且存在性别差异。性别差异的具体表现为，女生在4-5岁的发展快于男生，且在6岁开始出现下降趋势。 2. 排除入学影响，随年龄增长，6-7岁儿童的创造力显著上升。 3. 6岁已入学儿童的创造力显著低于同年龄未入学儿童，其中女生受到的影响更大。 4. 言语能力是讲故事创造力的基础，只有达到了一定水平的言语能力才能够表现出较高水平的创造力，但是言语能力只是讲故事创造力的必要而非充分条件。 5. 研究结果部分支持了创造力领域特殊性的理论。

7-11岁正常儿童和ADHD儿童故事重述能力及策略的发展

儿童的故事重述涉及工作记忆和抽象表征能力，是与儿童的日常学业任务密切联系。儿童能否把握时间线索来组织故事重述，反映的是儿童抽象出故事事件内在时间关系的能力，因此对儿童故事重述的探查可以揭示儿童抽象思维发展的一般规律和特点。本研究在前人研究的基础上，系统探查了7－11岁儿童故事重述能力及其策略的发展过程，探讨了时间线索对儿童故事重述的影响，并对ADHD儿童和正常儿童的故事重述及策略进行了比较。 主要研究结果如下： (1)7－11岁儿童故事重述能力总体上随年龄增长而提高，按正确顺序重述的事件数量增多，重述过程中提取和使用的时间线索也增加。其中7－9岁有较快速的发展。 (2)随故事中包含的事件数量的增加，故事难度增大，儿童的故事重述成绩有所下降，故事长度对7岁和9岁儿童的影响大于对11岁儿童的影响。 (3)有、无时间线索语词会影响儿童的故事重述。故事中包含时间语词线索有助于儿童的故事重述。11岁儿童的故事重述已不受有、无时间线索的影响，他们在无时间线索的条件下，更多地主动使用表示因果关系的语词来表征事件关系。 (4)ADHD儿童的故事重述能力在9岁到11岁有较快的发展。但总体而言，ADHD儿童对含有时间线索故事的重述能力显著差于正常儿童。 (5)故事再学习对ADHD儿童和正常儿童的故事重述都存在促进作用。但ADHD儿童故事再学习效果不如正常儿童，低龄儿童中差距尤其明显，随着年龄的增加，ADHD儿童与正常儿童故事再学习效果的差距逐渐缩小。 (6)不同年龄的儿童主要采用四种策略解决问题。随年龄增长，正常儿童和ADHD儿童中使用水平较高的内容主线和逻辑关系策略的人数都有所增加。但ADHD儿童中高水平策略使用人数比例仍低于正常儿童。

3-7岁儿童对情景化习俗道义情境中社会行为的认知发展

Children’s understanding of deontic rules and theory of mind (ToM) were the two research domains for children’s social cognition. It was significant for understanding children’s social cognition to combine the researches in the two domains. Children at 3, 5 and 7years were required to answer three questions according to the stories which happened in children’s familiar context. The three questions were designed to address the three problems:⑴Development of 3-7-Year-old children’s understanding about how the deontic rules were enacted or changed.⑵ Development of 3-7-Year-old children’s understanding about that the deontic rules and the actor’s mental states could impact on his behaviors.⑶ Development of 3-7-Year-old children’s capacity to integrate the deontic rules and mental state to evaluate the actor’s behavior. The results showed that: ① The 3-7-Year-old children had known that deontic rules were established by the authority’s speech act. But there were still some irrelevant factors which influenced the children’s judgments, such as the authority’s desire. ② The children gradually recognized the relationship between actors should do something and they will do the same thing. 3-year-old children could recognize such relationship in a way, but their predictions were usually influenced by some irrelevant factors. The children at 5 and 7 years old understood this relationship more steady. ③ In deontic context, more and more children predicted the actors’ behaviors according to the actors’ mental states as they grown up. The ratio that the 3-7-Year-old children predicted the actors’ behavior according to their false belief about the deontic rules was smaller in deontic context compared with the children’s performance in traditional false belief task. This maybe indicated that the deontic context influenced the children’s inference stronger than the physical context. ④ When they could get the actors’ desires and the deontic rules, all the children could predict the actors’ behaviors according to their desires, but not the deontic rules. It meant that all the children could understand that the actors’ desire mediated between the deontic rules and their behaviors. But when the actors wanted to transgress the deontic rules, all the children’s predications became less accurate. ⑤ When they assigned criticism, more and more children could discriminate different behaviors as a result of diverse mental states although they all transgressed the deontic rules. But the most part of children overweighed the deontic rules but overlooked the actors’ mental state about the deontic rules; their criticism to behaviors which transgressed the deontic rules just differ in quantity according to diverse mental states, that is: if the actors known the rules or want to transgress the rules, then punished more, and if the actors didn’t know the rules or transgress the rules accidentally, then punished a little.

7-12岁儿童执行功能与智力的关系

The nature of individual differences among children is an important issue in the study of human intelligence. There are close relation between intelligence and executive functions. Traditional theories, which are based mainly on the factor analysis, approach the problem only from the perspective of psychometrics. However, they do not study the relation of cognition and neurobiology. Some researchers try to explore the essential differences in intelligence from the basic cognitive level, by studying the relationship between executive function and intelligence. The aim of this study was to do the followings 1) to delineate and separate the executive function in children into measurable constructs; 2) to establish the relationship between executive function and intelligence in children; 3) to find out the difference and its neural mechanism between intellectually-gifted and normal children’s executive function. The participants were 188 children aged 7-12 year old. There were 6 executive function tasks. The results were follows: 1) The latent variables analyses showed that there was no stable construct of executive function in 7-10 year old children. The executive function construct of 11-12 year old children could be separated into updating, inhibition and shifting. And they had grown to be more or less the same as adults in the executive function. There were only moderate correlations between the three types of executive function, but they were largely independent of each other. 2) The correlations between the indices of updating, inhibition, shifting and intelligence were different in 7-12 year old children. The older the age, the more the indices were related to intelligence. The updating and shifting were related to intelligence in 7-10 year old children. There were significant correlations between the updating, inhibition, shifting and intelligence in 11-12 year old children. The correlation between updating and intelligence was higher than the correlation between shifting and intelligence. Furthermore, in structural equation models controlling for the three executive functions correlations, updating was highly related to intelligence, but the relations of inhibition and shifting to intelligence were not significant. 3) Intellectually-gifted children performed better than normal children in executive function tasks. The neural mechanism differences between intellectually gifted and average children were indicated by ERP component P3. The present study helps us to understand the relationship between intelligence and executive function; and throws light on the issue of individual differences in intelligence. The present results can provide theoretical support for the development a culture-free intelligence test and a method to promote the development of intelligence. Our present study lends support to the neural efficient hypothesis.

Cultivar de trigo BRS 194 testada e indicada para cultivo nas regiões de adaptação 7 e 8 do Paraná e 9 e 10 do Mato Grosso do Sul.

2005