半间歇悬浮聚合法合成SMI树脂

采用半间歇悬浮聚合法合成了只表面出单一玻璃化转变温度（Tg)的苯乙烯－N－苯基马来酰亚胺共聚物（SMI），讨论了影响聚合反应的主要因素，当反应温度为60－75摄氏度，活性磷酸钙为悬浮剂，单体苯乙烯的配比为45－75时，用半间歇悬浮聚合法合成了组成均一，只表现出1个Tg的SMI，其收率可达99％以上。     

锗对重掺硼直拉硅中氧沉淀的影响

通过单步长时间退火(650～1150℃/64h)和低高两步退火(650℃/16h+1000℃/16h和800℃/4～128h+1000℃/16h),研究锗对重掺硼硅(HB-Si)中氧沉淀的影响.实验结果表明,经过退火后,掺锗的重掺硼硅中与氧沉淀相关的体微缺陷密度要远远低于一般的重掺硼硅,这表明锗的掺人抑制了重掺硼硅中氧沉淀的生成,并对相关的机制做了初步探讨.     

高碳CZ硅中氧沉淀的两种成核长大机制

应用红外光谱、高分辨透射电镜研究了高碳CZ硅中的氧沉淀.实验表明:高碳样品中有两种成核长大机制形成的氧沉淀,一是多碳中心的异质成核长大的氧沉淀,碳原子同时参与氧沉淀的成核和长大,红外光谱上1230cm-1处无氧沉淀的特征峰,TEM观察这种氧沉淀是10～30nm高密度的球状小沉淀;另一种氧沉淀类似于低碳样品中均匀成核长大的氧沉淀,它在红外光谱上1230cm-1处有吸收峰,TEM观察这种氧沉淀是100～300nm各种形态的大沉淀.热处理条件不同可以改变两种机制相互竞争的优势,低于900℃的热处理以异质成核为主,而只有经过1200℃高温预处理破坏异质核心后,再在900℃以上热处理时,均匀成核长大的氧沉淀才会占优势.     

煤矿安全生产可视化监控系统的设计与实现

文中从可视化管理的角度提出了基于地理信息技术实现煤矿安全和生产集中管理的思路,提出了"分散管理、集中监控"的建设思想,通过对系统总体框架、实现方法以及基本功能的描述,可为煤矿安全管理部门建立监控和生产一体化系统提供借鉴参考。     

吸收-喷射复合制冷技术的研究进展

综述了吸收－喷射复合制冷技术近年来的研究状况，分析了目前研究所取得的成果，指出今后值得深入研究方向。     

氮对直拉硅片中氧沉淀分布的影响

研究了氮在退火过程中对直拉硅片中的氧沉淀分布的影响.实验结果表明,三步退火后在掺氮硅片截面形成特殊的M形的氧沉淀密度分布,即表面形成没有氧沉淀的洁净区(DZ) ,体内靠近DZ区域形成高密度、小尺寸的氧沉淀,而在硅片的中心处形成低密度、大尺寸的氧沉淀.分析认为,由于在第一步高温退火过程中氮在硅片表面外扩散,同时在硅片体内促进氧沉淀,改变了间隙氧的分布,从而导致在随后的热处理过程中氧沉淀的特殊分布行为     

氮气氛直拉硅的本征吸杂的研究

本文利用化学腐蚀、扩展电阻探针、透射电镜和电子探针等研究了氮气氛直拉硅的本征吸杂。经高——低——高三段热处理可获得比较完整的洁净区,体内有高密度且分布均匀的氧沉淀及其诱生缺陷,它们具有吸杂能力。洁净区内有片状残余缺陷。跟氩气氛直拉硅相比,氮气氛直拉硅的氧沉淀及其诱生缺陷有些不同。体内沉淀除片状外,主要是四面体。层错中央无氧沉淀。位错环是由氧沉淀诱生位错成为F—R源增殖的。     

Adults' demonstration of underlying Euclidean concepts in relation to task context.

In studies in which Piagetian water-level (horizontality) and plumb-line (verticality) tasks are administered to young adults, females are typically less successful than males. Women may, however, have the underlying spatial competence to use horizontal and vertical axes, but they may be less likely to activate this competence because they lack adequate knowledge of the relevant physical phenomena. To evaluate this possibility, 80 male and 80 female undergraduates were given horizontality and verticality tasks in which knowledge of the physical phenomena was or was not relevant. Results show that sex differences were evident only when knowledge of the physical phenomena was needed. These data support a performance rather than a competence interpretation of adult women's difficulties in the standard Piagetian tasks. Developmental and educational implications are discussed. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term memory for pictures related to seriation, horizontality, and verticality concepts.

To evaluate Piaget and Inhelder's (1973) hypothesis that memories are related to operative levels, 82 kindergarten and 101 4th-grade children were shown pictures involving seriation, horizontality, and verticality and were asked to reproduce them 1 wk and 5 mo later. In addition, tasks to assess seriation, horizontality, and verticality concepts were given to half of the children in the fall and to all children in the spring. Although there were some significant correlations between memories and operative levels, the relations were quantitatively weak and were undermined by several serious disconfirmations. Furthermore, although long-term memory improvements did occur, these were not systematically linked to individuals' operative development, nor did they occur significantly more often than memory deteriorations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)