中国北方风成堆积的风化作用与环境变迁—U-Th、~(10)Be及元素地球化学的研究

The surface of the Earth is continuously undergoing changes as a result of weathering-erosion, plate tectonics and volcanic processes. Continental weathering-erosion with its complex rock-water interactions is the central process of global biochemical cycling of elements, and affects the long-term ocean atmosphere budget of carbon dioxide both through the consumption of carbonic acid during silicate weathering and through changes in the weathering and burial rates of organic carbon. Rates of the weathering-erosion depend on a variety of factors, in particular rock properties and chemical composition, climate (especially rainfall), structure, and elevation. They are quite variable on a regional scale. Thus, environmental changes in a region could be indicated by the history of weathering-erosion in the region. Recent attention has focused on increased silicate weathering of tectonically uplifted areas in the India-Asia collision zone as a possible cause for falling atmospheric CO_2 levels in the Cenozoic era. The wind blown dust deposits in the Loess Plateau is derived from the arid and semiarid regions in northwestern China, in turn, where the deposits have been derived from the Qinghai-Xizang Plateau and the high mountains around. Therefore, geochemistry of the wind blown loess-paleosol and red clay sequences may provide insight both to paleoenvironmental changes on the Loess Plateau, and to the uplift and weathering-erosion histories of the Qinghai-Xizang Plateau. In this paper, uranium-thorium series nuclides and cosmogenic ~(10)Be have been employed as tracers of weathering intensities and histories of the dust sediments in the Loess Plateau. Major elements, such as Na, Al, Fe etc., are also used to estimate degree of chemical alteration of the dust sediments and to rebuild the history of weathering on the Loess Plateau. First of all, using a low-level HPGe γ-ray detector, we measured U and Th series nuclides in 170 loess and paleosol samples from five sites in the Loess Plateau, going back 2.6 Ma. The results show that ~(238)U activities are disequilibrium with its daughter nuclide ~(230)Th in young loess-paleosol sequence, indicating that weathering was happened both in dust deposition site and in dust source regions. Using concentrations of ~(238)U and ~(232)Th in the samples, we estimated the amounts of ~(238)U leached out of from paleosols due to weathering. Further, based on analyses of ~(230)Th in paleosols deposited in the past ca. 140 ka, we determined when the paleosols weathered in the source regions. We conclude that most of the weathering in the dust-source regions may have occurred during the interglacials before dust deposition.

应用解析水平理论考察时间距离对决策的影响

Construal Level Theory is a kind of social cognitive theory, with the main conclusion of that the more time distance is, the more people use high level construal and the more high level construal affect in judging, decision making and such of these cognitive processes, and the low level construal has the mirror process as well. In these ten years, construal level theory is developing very fast and some of the researches of consumer behavior has concerned this developed trend very much. In 2007’s Journal of Consumer psychology, half of the papers focused on construal topics and ask for more researches about these topics. So our research mainly focused on such topics, the application of construal level theory in consumer behavior research. The first part is contained 3 experiments which mean to discuss the questions from reviewing the prior literatures. The research methods, manipulated definition, construal level factors VS construal level events are the goal of first part of this study. The results showed that construal level’s effect might be a consecutive variable and has a consecutive trend when time goes by. Time distance might not be a semantic cognitive effect to construal level but a internal ones for when there’s no verbal information of time distance the results would have the same one as well. The second part of the study is focus on a simplified model of decision-making, which contained two times decision-making, to detect whether and how would the prior decision making affect the next decision making. The study conducted the time distance in first decision making with the situation for the decision and conducted the second time distance in the time distance between the two decision situations. Although we couldn’t get the detail of the weight changes in construal level factors limited by our research, we can have a logical hypothesis based on “one-down- the other-up”. The results showed that the level of construal factors can affect the memory and the more the factors affected, the bigger the error would be. The first time distance and second time distance could effect the second decision in a interaction-way, and support the hypothesis. The whole research is mean to explore the application of construal level theory in consumer behavior research. The conclusion suggests that the periods of products and the consuming may need different marketing strategies in a long-term perspective and time distance should be control are detected in marketing analysis even there’s no time information on the paper.

颜色在自然场景知觉中的作用

Color has an unresolved role in the rapid process of natural scene. The temporal changes of the color effect might partly account for the debates. Besides, the distinction of localized and unlocalized information has not been addressed directly in these color studies. Here we present two experiments that investigate whether color contributes to categorization in a briefly flashed natural image and also whether it is mediated by time and low-level information. By controlling the interval between target and mask stimuli, Experiment 1 tested the hypothesis that colors could facilitate in the early stage of scene perception and the effect would decay in later processing. Experiment 2 examined how the randomization of local phase information influenced the color’s advantage over gray. Together, the results suggest that color does enhance natural scene categorization at short exposure time. Furthermore, results imply that effect of color is stable between 12 and120ms, and is not accounted by showing the structures organized by localized information. Therefore，we concluded that color always make effect in the process of rapid scene categorization, and do not depend on localized information. Thus, the present study is an attempt to fill the gap in previous research; its results is an contribution to deeper understanding of the role of color in natural scene perception.

相同知识背景下技能之间迁移机制的研究

Since the middle of 1980's, the mechanisms of transfer of training between cognitive subskills rest on the same body of declarative knowledge has been highly concerned. The dominant theory is theory of common element (Singley & Anderson, 1989) which predict that there will be little or no transfer between subskills within the same domain when knowledge is used in different ways, even though the subskills might rest on a common body of declarative knowledge. This idea is termed as "principle of use specificity of knowledge" (Anderson, 1987). Although this principle has gained some empirical evidence from different domains such as elementary geometry (Neves & Anderson, 1981) and computer programming (McKendree & Anderson, 1987), it is challenged by some research (Pennington et al., 1991; 1995) in which substantially larger amounts of transfer of training was found between substills that rest on a shared declarative knowledge but share little procedures (production rules). Pennington et al. (1995) provided evidence that this larger amounts of transfer are due to the elaboration of declarative knowledge. Our research provide a test of these two different explanation, by considering transfer between two subskills within the domain of elementary geometry and elementary algebra respectively, and the inference of learning method ("learning from examples" and "learning from declarative-text") and subject ability (high, middle, low) on the amounts of transfer. Within the domain of elementary geometry, the two subskills of generating proofs" (GP) and "explaining proofs" (EP) which are rest on the declarative knowledge of "theorems on the characters of parallelogram" share little procedures. Within the domain of elementary algebra, the two subskills of "calculation" (C) and "simplification" (S) which are rest on the declarative knowledge of "multiplication of radical" share some more procedures. The results demonstrate that: 1. Within the domain of elementary geometry, although little transfer was found between the two subskills of GP and EP within the total subjects, different results occurred when considering the factor of subject's ability. Within the high level subjects, significant positive transfer was found from EP to GP, while little transfer was found on the opposite direction (i. e. from GP to EP). Within the low level subjects, significant positive transfer was found from EP to GP, while significant negative transfer was found on the opposite direction. For the middle level subject, little transfer was found between the two subskills. 2. Within the domain of elementary algebra, significant positive transfer was found from S to C, while significant negative transfer was found on the opposite direction (i. e. from C to S), when considering the total subjects. The same pattern of transfer occurred within the middle level subjects and low level subject. Within the high level subjects, no transfer was found between the two subskills. 3. Within theses two domains, different learning methods yield little influence on transfer of training between subskills. Apparently, these results can not be attributed to either common procedures or elaboration of declarative knowledge. A kind of synthetic inspection is essential to construct a reasonable explanation of these results which should take into account the following three elements: (1) relations between the procedures of subskills; (2) elaboration of declarative knowledge; (3) elaboration of procedural knowledge. 排Excluding the factor of subject, transfer of training between subskills can be predicted and explained by analyzing the relations between the procedures of two subskills. However, when considering some certain subjects, the explanation of transfer of training between subskills must include subjects' elaboration of declarative knowledge and procedural knowledge, especially the influence of the elaboration on performing the other subskill. The fact that different learning methods yield little influence on transfer of training between subskills can be explained by the fact that these two methods did not effect the level of declarative knowledge. Protocol analysis provided evidence to support these hypothesis. From this research, we conclude that in order to expound the mechanisms of transfer of training between cognitive subskills rest on the same body of declarative knowledge, three elements must be considered synthetically which include: (1) relations between the procedures of subskills; (2) elaboration of declarative knowledge; (3) elaboration of procedural knowledge.

通过对心理学期刊的几项统计分析看我国十年来儿童发展教育心理学研究状况与动向

In this study, bibliometric method was usded in the investigation of 2274 papers concerning child developmental and educational psychology, which were published during the ten years of 1979-1988, in 14 psychological journals and 97 other scientific journals. According to the quantitative and qualitative analyses, the results are as follows: 1979-1988 saw the rapid development and prosperous period in China's child developmental and educational psychology, During which more papers were published and more fields couched than in the psvious thirty years. The number of literature publications increased and went to the peak in 1983 and 1984, and came down since 1985. The trend was found to result from the decrease in popular science introductions of psychology, which reflected that a heat of psychology had appeared in 1983 and started to cool in 1985. At the mean time, the number of research reports had been holding a steady increase by 1987 and decreased obviously in 1988, especially in the fields of cognitive and social development. There could be several possible explanations of this phenonemon: Piagetian studies are becoming fewer and the eakening of Piaget's influence might predict a period of standstill in the field of developmental psychology in China; As researches become more and more difficult, researchers have turned to be more cautious in lay out their reports; the cutdown of fees and staff could also be one of reasons for less publication in 1988. As the factors mentioned above still exist and their influences last, the number of papers are not expected to increase in the near future. The field of thinking and menory is closely connected with that of artificial intelligence. The downhill situations in these two fileds should be taken seriously. 2. The types of research work are divided on the bases of their problem raising. The trends show that the deepening studies, which represent a comaratively higher level of exploration, are waving fewer, while repeated studies and creative studies are becoming more as the years go along. This fact is worth being further analysed. Big progress could be seen from research methods. The methods currently used are mainly experiment, psychological measurement and assessment, and theoretical reasoning. There is a rapid increase of research by using scales. Wechsler Intelligence Scale for Children, Binet Scale and Baley Scale have been revised andstandardized. Chinese researchers have also developed several good scales of their own, some of which are valuable and need to be standardized. In the papers investigated, the amount of citation is significantly lower than the world average level as well as the average citation number of whole China's scientific literature. Among the papers cited, most are of Chinese and English languages, and only a small rate were published in resently five years. The renewal of literature cited seems to stay at a low level in the ten years. Tremendous work could be reflected by the number of subjects used the research work in those ten years: 362665. A lot of studies piled on the period of 4-16 year olds. Compared with the previous thirty years, the age range was much enlarged and there were quite a few studies about preschool, school and adolescent periods. The study of newborn of 0-3 has been a weak point so far and it is a field to which chinese developmental psychologists should pay more attention. The progress in using statistics is one of the most obvious part in the development in the research work of child developmental and educational psychology. The one tendency that should be awared and avoid is to put the cart before the horse: seeking for more sophisticated statistic method while neglecting the meanings of research problems. 3. Citation analysis was used in selecting scholars who had great influence in the field of child developmental and educational psychology. Among the often cited and famous scholars, 31 are Chinese researchers and 12 are Western psychologists. The authoritative journal for child developmental psychology and educational psychology is Acta Psychologica Sinica.

CO hydrogenation to light alkenes over Mn/Fe catalysts prepared by coprecipitation and sol-gel methods

CO hydrogenation to light alkenes was carried out on manganese promoted iron catalysts prepared by coprecipitation and sol-gel techniques. Addition of manganese in the range of 1-4 mol.% by means of coprecipitation could improve notably the percentage of C-2 (=) similar to C-4 (=) in the products, but it was not so efficient when the sol-gel method was employed. XRD and H-2-TPR measurements showed that the catalyst samples giving high C-2 (=) similar to C-4 (=) yields possessed ultra. ne particles in the form of pure alpha-(Fe1-xMnx)(2)O-3, and high quality in lowering the reduction temperature of the iron oxide. Furthermore, these samples displayed deep extent of carburization and different surface procedures to the others in the tests of Temperature Programmed Surface Carburization (TPSC). The different surface procedures of these samples were considered to have close relationship with the evolving of surface oxygen. It was also suggested that for the catalysts with high C-2 (=) similar to C-4 (=) yields, the turnover rate of the active site could be kept at a relatively high level due to the improved reducing and carburizing capabilities. Consequently, there would be a large number of sites for CO adsorption/dissociation and an enhanced carburization environment on the catalyst surface, so that the process of hydrogenation could be suppressed relatively to a low level. As a result, the percentage of the light alkenes in the products could be raised.