Nitridation Kinetics of Silicon Monocrystal and Morphology of Nitride Film

Basing on TGA (thermal gravimetric analysis) of thermal nitridation at l200, l250, l300℃, respectively,analysis of high temperature kinetics for nitridation of silicon monocrystal has been carried out. According tothe theory for kinetics of reaction of vapour with solid phase a nitridation kinetic model, from which it can beshown thal the rate of nitridation reaction of silicon crystal should be controlled by three stage limiting factors,was proposed. These limiting factors are chemical reaction, chemical reaction mixed with diffusion and diffu-sion. Using this model to treat our experimental data, satisfactory correlation coefficient and apparentactivation energy of nitridation of p-type (lll) silicon crystal have been obtained. The nitride film was identi'fied to be a-Si_3N_4 (Hexagonal, a=0.7758nm,c_o=0.5623nm) by X-ray diffraction analysis. Morphology ofthe nitride films formed in different nitridation duration was observed in both planar andcross-sectional viewsby SEM (scanning electron microscope).     

采用氮保护气氛生长的功率晶体管用硅单晶的研究

本文论述在纯氮气氛中生长硅单晶技术,根据器件工艺要求,与器件厂相互配合,取得了功率晶体管成品率的大幅度提高,肯定了氮保护气氛下生长的硅单晶的优越质量。     

铁体系催化剂制备方式对催化活性的影响

研究了加料顺序,陈化方式,陈化条件,对Fe(naph)_2—Al(i—Bu)_3——CH_2=CHCl体系催化丁二烯聚合活性的影响。结果发现按Bd+Fe+Cl+Al的加料顺序配制的催化剂的活性高于其它加料顺序;陈化方法不能提高催化剂的活性。     

An investigation of thermoelectric cooling devices for small‐scale space conditioning applications in buildings

This paper presents the study of a thermoelectric cooler (TEC) designed for small‐scale space conditioning applications in buildings. A theoretical study was undertaken to find the optimum operating conditions, which were then applied in the laboratory testing work. A TEC unit was assembled and tested under laboratory conditions. Eight pieces of UltraTEC were shown to generate up to 220 W of cooling with a COP of 0.46 under the input current of 4.8 A for each module. Thermo‐economical analysis was carried out and results showed that a system with PV panel can compete with an equivalent system without a PV panel when PV costs fall down to or lower than £1.25 per Watt. For the cases without a PV panel, the system with a high level of TEC power input delivered a better performance in terms of the average cooling energy price than that system with a low level of TEC power input after critical interest rate (currently 4%). Copyright © 2009 John Wiley & Sons, Ltd.     

p型微氮直拉硅中氧施主的电学特性

研究了p型含氮以及不含氮直拉(CZ)硅中热施主(TD)以及氮氧(N-O)复合体的电学性质.硅片在350～850℃范围进行不同时间的退火后,利用四探针和通过室温傅里叶红外光谱(FTIR)分别测量其载流子浓度和间隙氧浓度的变化.实验结果表明:p型含氮直拉硅(NCZ)中热施主的电学特性基本与n型NCZ硅相同,但N-O复合体的消除温度明显低于n型NCZ硅,这是由于p型NCZ硅中硼促进了N-O复合体的消除.     

采矿权勘测定界测量精度研究

为实现采矿权勘测定界工作科学化、规范化、精准化,研究制定采矿权勘测定界技术规程已刻不容缓。本文基于矿业权“三位一体”权利结构的解析,从准入资质、国土空间管控行政权及资产物权三个维度,梳理了相关技术标准对勘测定界测量精度的规定,确定采矿权勘测定界测量精度应分级规制,不应一刀切。从物权角度探讨了采矿权勘测定界测量精度的决定因素,规定了三个等级采矿权勘测定界测量中误差分别为0.1、0.2、1.0m。最后提出了关于矿区范围拐点坐标数值只需保留两位的政策建议。     

Understanding person-space-map relations: Cartographic and developmental perspectives.

Drawing from cognitive-developmental and cartographic theory, the authors tested children's understanding of person–map–space relations. After introducing maps of the classroom, an adult moved to different positions in the room and pointed straight ahead. Five- to 12-yr-old children (N?=?259) placed colored arrow stickers on the map to show the person's location and heading, once when the map was aligned with the room and once when rotated 180°. Performance was better on the aligned condition and when headings were parallel to the nearby wall; most younger children failed to understand point of view; and sex differences favored boys. Data from 168 children given additional spatial tasks were consistent with the hypothesized importance of projective spatial concepts for mapping. Data suggest that it is geometric (spatial) rather than representational (symbolic) space–map correspondences that pose particular difficulty for older children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

反应块及其在类比推理中的应用

本文讨论了类比在问题求解中的应用问题．给出了应用反应块识别类比源以及自动生成反应块的算法．本文还给出了一种解法序列分割方法，用于类比源的获取及存储．这些思想和方法已在符号积分求解与学习系统ＩＳＬＳ（ｉｎｔｅｇｒａｔｉｏｎｓｏｌｖｉｎｇａｎｄｌｅａｒｎｉｎｇｓｙｓｔｅｍ）中实现．     

The operative basis of performance on Piagetian memory tasks: Evidence from normal and learning disabled children.

Investigated the role of operative schemes in explaining older children's superior memory on past Piagetian memory tasks. In Exp I, 60 1st–4th grade concrete operational children—half with deficits in visual memory (learning disabled, LD)—reconstructed 2 stimuli in which operative schemes were or were not relevant (a seriated array vs an arbitrary color sequence). As predicted, LD children performed significantly worse than normals on the arbitrary stimulus only. Exp II tested whether this difference resulted simply from differential task difficulty. 28 preschoolers who either could or could not seriate reconstructed both stimuli. Only seriaters performed significantly better on the operative stimulus than on the arbitrary stimulus, supporting the Piagetian position. (2 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for developmental differences in spontaneous seriation and its implications for past research on long-term memory improvement.

One possible explanation of the long-term memory improvement for seriated stimuli reported by Piaget and B. Inhelder (1973) is that there is a developmental increase in the tendency to seriate any drawing spontaneously. Results of an earlier study by R. Altemeyer et al (see record 1970-02150-001) do not support this explanation. In the present study, a total of 377 kindergarten, 1st-, 2nd-, and 3rd-grade children were tested to determine whether other developmental changes in drawings might have obscured an underlying change in the tendency to seriate. Using Altemeyer's procedure, which required children to draw pictures from a relatively vague hint, no developmental change in seriation was found. However, a significant developmental increase in the production of representational drawings did occur. This latter age difference was eliminated by using a more informative hint, and with this modification, a developmental increase in the tendency to seriate was revealed. Results are discussed in relation to previous Piagetian memory research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)