A longitudinal study of preschool children's (homo sapiens) sex segregation.

In this 2-year longitudinal study, we hypothesized that sex of the human child (Homo sapiens), differences in physical activity, and time of the year would interact to influence preschool children's sex segregation. We also hypothesized that activity would differentially relate to peer rejection for boys and girls. Consistent with the first hypothesis, high-activity girls started off as the most integrated group but became more segregated with time, whereas high-activity boys remained the most segregated group across the duration of the study. The second hypothesis was also supported: For girls only, activity was significantly related to peer rejection during Year 1 only, the time when high-activity girls also interacted frequently with boys. Results are discussed in terms of sexual selection theory and gender boundary violations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

奥尔特加和赫钦斯大学思想的比较分析——基于对《大学的使命》和《美国高等教育》的解读

对奥尔特加和赫钦斯著作的理解需要突破以往"条块化"的解读方式,尽量忠于原著内容及其论述逻辑。奥尔特加和赫钦斯对大学问题有类似的看法,但对何为大学的使命以及如何达成这种使命的主张有本质不同,前者力图恢复大学的文化活力,通过"文化传授"建立符合时代的"核心思想体系",后者强调大学的理智特征,希望通过"普通教育"构筑共同的知识基础,重建大学的"理性秩序"。二者的大学思想均带有保守主义的倾向,并体现出一定程度的不确定性和不彻底性;对其比较分析将有助于更加准确地把握各自的重心及相互的差异,同时为今日反思大学使命与大学改革等议题提供有益的借鉴。     

化学镀Ni-P-SiO2复合镀层的晶化行为研究（英文）

将纳米SiO2颗粒加入到化学镀液中制备出纳米SiO2颗粒强化复合镀层,并对得到的复合镀层的组织结构和晶化行为进行研究。结果表明:纳米颗粒的加入没有影响到镀层的非晶结构,复合镀层仍为非晶态,加热后镀层发生晶化,纳米颗粒降低了镀层的晶化温度,镀层的晶化激活能从254.28下降到220.30kJ/mol。     

光分组交换系统的结构研究

对光分组交换系统的几种结构进行了分类和比较研究,介绍了已研制成功的2.5Gbit/s光ATM交换实验系统的结构,给出了测试波形图,说明了工作机理。     

Mo和W在镍基单晶高温合金中的作用研究进展综述

镍基单晶高温合金因其优异的高温性能而广泛应用于航空发动机涡轮叶片的制备。经过几十年的发展,国外已发展至第六代镍基单晶高温合金,合金体系中的Re和Ru等贵重金属元素的含量也不断增加。贵重元素的添加导致合金的成本和密度上升,对合金的研制和批量商业化应用不利。Mo和W作为较低成本的强化元素,在镍基单晶高温合金中发挥了重要的作用。Mo 和W在镍基单晶高温合金中的作用已有较为广泛的研究,本文简单综述了Mo和W在镍基单晶高温合金中对微观结构,包括元素分布、γ/γ′相两相结构、组织稳定性等方面,以及高温持久性能、对凝固缺陷和抗氧化及抗热腐蚀性等的影响,并提出了未来潜在的研究方向。     

White‐Emitting Tuning and Energy Transfer in Eu2+/Mn2+‐Substituted Apatite‐Type Fluorophosphate Phosphors

Herein, a series of Eu²⁺&Mn²⁺substituted fluorophosphates Ca₆Gd₂Na₂(PO₄)₆F₂ phosphor with apatite structure have been synthesized and investigated by the powder X‐ray diffraction, photoluminescence spectra, fluorescence decay curves, thermal quenching, and chromaticity properties. Particularly, both Eu²⁺ and Mn²⁺ emissions at the two different lattice sites 4f and 6h in Ca₆Gd₂Na₂(PO₄)₆F₂ matrix have been identified and discussed. The dual energy transfer of Eu²⁺→Mn²⁺ and Gd³⁺→Mn²⁺ in Ca₆Gd₂Na₂(PO₄)₆F₂:Eu²⁺,Mn²⁺ samples have been validated and confirmed by the photoluminescence spectra. The dependence of color‐tunable on the activator concentration of Mn²⁺ was investigated to realize white light emission. By varying the doping concentration of the Mn²⁺ ion, a series of tunable colors including pure white light and candle light are obtained under the excitation of 350 nm. Moreover, the fluorescence decay curves have been fitted and analyzed using the Inokuti–Hirayama theoretical model to estimate the Eu–Mn interaction mechanism. We also investigated temperature‐dependent photoluminescence quenching characteristics according to the Arrhenius equation. Preliminary studies on the properties of the phosphor indicated that the obtained phosphors might have potential application as a single‐component white‐emitting phosphor for UV‐based white LEDs.     

余热发电运行初期的操作注意事项

<正>目前,水泥窑余热发电技术已经非常成熟,正常运行过程中问题都比较少,但在余热发电投运初期往往会问题集中暴露。本文以济源中联7.5 MW纯低温余热发电机组为例,就调试期间采取的比较典型和常见问题处理措施与大家分享。1控制锅炉换热管束壁的结露余热发电投运初期,特别是在冬季,锅炉内部温度很低,在锅炉升温的时候,锅炉的换热管束就     

不同络合剂改性活性炭的松香歧化用Pd/C催化剂性能

采用3种不同络合剂(马来酸、柠檬酸钠、水杨酸钠)对活性炭进行改性,并以未经改性的活性炭为对比,研究了络合剂改性活性炭对Pd/C催化剂的松香歧化性能的影响。傅里叶变换红外(FTIR)、X射线衍射(XRD)、X射线光电子能谱(XPS)及透射电镜(TEM)结果表明,经过马来酸、柠檬酸钠和水杨酸钠修饰改性的活性炭表面存在与Pd具有较强络合能力的配离子,这些配离子成为Pd前驱体的吸附锚定位,有利于形成粒径较小的Pd颗粒,提高了Pd的利用率。以改性后的活性炭为载体,制备得到的Pd/C催化剂活性均明显高于未经处理的活性炭的。     

管壳式甲醇合成装置增产节能改造技术

针对管壳式甲醇合成塔不易大型化、催化剂装填率低、催化剂更换周期短等缺点,对甲醇合成塔进行了改造,结果表明,增加了单塔的生产能力,提高了催化剂的更换周期;对合成装置中的甲醇分离器进行了改造,提高了甲醇的分离效率,降低了循环气中的甲醇含量,从而提高了CO的单程转化率,提高了醇净值;通过对甲醇合成塔和甲醇分离器的改造,整体单系列生产能力比原装置生产能力提高了10%以上,有效地降低了生产成本,而不影响装置的安全性和操作稳定性。     

动力作用下硬颗粒诱发裂缝弯曲和分叉机理研究

脆性材料在动荷载作用下的裂缝弯曲和分叉行为,对深入了解材料的抗拉特性和破坏模式有着重要意义。基于损伤演化原理的有限元方法,针对脆性材料中颗粒物诱发裂缝分叉的机理展开研究,通过比较无颗粒与有颗粒两种裂缝扩展模式,分析了硬颗粒对裂缝扩展模式的影响。结果显示,当颗粒物刚度较大物性较好、裂缝扩展遭遇颗粒时裂隙将沿着交界面绕行,易发生弯曲分叉,两者具有迥异的扩展模式。