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.

等离子体材料加工

就等离子喷涂及材料合成原理作简单叙述，着重介绍了等离子体材料加工技术在膜层沉积、微电子器件加工及金属熔炼等方面的应用。

波动方程反演问题的一种新的逼近方法

本文给出了一种求解波动方程反演问题的“多目标函数法”.这种方法简单、有效,并具有明确的物理意义.对于三维问题的程序化它有很强的优越性.

The effects of coil current distribution in a cylindrical electron-cyclotron-resonance reactor

Using a 2-D hybrid model, the authors have found that external currents play an important role in the plasma parameters in the reactor. The plasma density, temperature and electrostatic potential would be significantly influenced by the applied external currents.

带电胶体粒子结晶过程的实验研究

利用带电单分散聚苯乙烯胶体粒子,通过自组装机理,制备了体积百分比为4·8%的具有多晶结构的胶体晶体,并用Kossel衍射技术和紫外可见分光光度计分别对晶体的生长过程进行了监测.通过对Kossel的图像分析检测不同阶段相应的晶格结构,发现胶体结晶过程晶体结构演变顺序为由液态—随机层结构—堆无序结构—面心立方孪晶结构到面心立方结构.定量地确定了结晶过程中晶体不同晶面的晶面间距和晶体的晶格常数,通过紫外可见分光光度计测量的晶体透射谱图,计算得到111晶面的晶面间距和晶体的晶格常数,与用Kossel衍射技术得到的结果相一致,还发现随样品放置时间的延长,衰减峰变窄和加深,并向短波方向移动,对应着晶体的晶格常数减小的现象.

聚光光伏系统

随着传统化石类能源的枯竭和环境污染的日益严重,太阳能光伏发电技术倍受瞩目,但较高的发电成本及原材料的缺乏制约了其大规模发展.以高转换效率、低芯片消耗为核心的聚光光伏技术,在降低光伏发电成本方面被人们寄予厚望.文章主要介绍了聚光光伏系统发展的历史和现状,工作原理及存在的关键问题,并对其发展前景进行了展望.

力学研究所成立五十周年感言

在庆祝我的同事和朋友钱学森所创立的力学研究所成立50周年之际，我很荣幸能在此讲几句话。当然，我未能与你们中的多数人一样，在力学所成立初期，参加你们的工作．你们的这段经历令我羡慕不已但是另一方面，在钱学森回国之前，在他计划为新中国的科学和技术的发展做出贡献的时候，我就在他的身边，正是这一时期孕育了他的这些想法。

Spatial and Temporal Variation of LURR and Its Implication for the Tendency of Earthquake Occurrence in Southern California

Based on the theory of LURR and its recent development, spatial and temporal variation of Y/Y-c (value of LURR/critical value of LURR) in the Southern California region during the period from 1980 through March, 2001 was studied. According to the previous study on the fault system and stress field in Southern California, we zoned the Southern California region into 11 parts in each of which the stress field is almost uniform. With the time window of one year, time moving step of three months, space window of a circle region with a radius of 100 km and space moving step of 0.25 degree in latitude and longitude direction, the evolution of Y/Y-c were snapshot. The scanning results show that obvious Y/Y-c anomalies occurred before 5/6 of strong earthquakes considered with a magnitude of 6.5 or greater. The critical regions of Y/Y-c are near the epicenters of the strong earthquakes and the Y/Y-c anomalies occur months to years prior to the earthquakes. The tendency of earthquake occurrence in the California region is briefly discussed on the basis of the examination of Y/Y-c.

Spatio-Temporal Scanning and Statistical Test of the Accelerating Moment Release (AMR) Model Using Australian Earthquake Data

The Accelerating Moment Release (AMR) preceding earthquakes with magnitude above 5 in Australia that occurred during the last 20 years was analyzed to test the Critical Point Hypothesis. Twelve earthquakes in the catalog were chosen based on a criterion for the number of nearby events. Results show that seven sequences with numerous events recorded leading up to the main earthquake exhibited accelerating moment release. Two occurred near in time and space to other earthquakes preceded by AM R. The remaining three sequences had very few events in the catalog so the lack of AMR detected in the analysis may be related to catalog incompleteness. Spatio-temporal scanning of AMR parameters shows that 80% of the areas in which AMR occurred experienced large events. In areas of similar background seismicity with no large events, 10 out of 12 cases exhibit no AMR, and two others are false alarms where AMR was observed but no large event followed. The relationship between AMR and Load-Unload Response Ratio (LURR) was studied. Both methods predict similar critical region sizes, however, the critical point time using AMR is slightly earlier than the time of the critical point LURR anomaly.

Infrared (1.2-1.6 mu m) luminescence in Cr4+: Yb3Al5O12 single crystal with 940 nm diode pumping

Infrared (1.2-1.6 mu m) luminescence in a ytterbium aluminium garnet (YbAG) crystal, doped with Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.34 mu m and measured to be about 1.3 times with respect to Yb3+ IR luminescence (lambda = 1.03 mu m). We demonstrate that for the excitation wavelength of 940 nm Yb3+ ions act as sensitizers of the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as a high-efficient system for tunable laser (1.2-1.6 mu m) output. (c) 2004 Elsevier B.V. All rights reserved.