壳聚糖/SiO2复合材料制备及质子传导性能研究

采用浸渍法在二氧化硅多孔材料中负载壳聚糖制备壳聚糖/SiO2复合材料,通过X射线衍射、扫描电子显微镜、傅立叶变换红外光谱等方法对所制备材料的组成与结构进行了表征,采用热重-差示扫描量热法研究了复合材料的热稳定性,采用电流中断法测定所制备材料的电导率来衡量其质子传导性能,并考察了壳聚糖溶液浓度对壳聚糖/SiO2复合材料导电性能的影响。结果表明,壳聚糖/SiO2复合材料具有较高的热稳定性,复合材料的电导率随着壳聚糖乙酸溶液浓度的增加而增加,当壳聚糖乙酸溶液质量百分比浓度为2.5%时,电导率可达1.82 S/cm。     

Behavior of slender steel concrete composite columns in eccentric loading

Ten slender steel reinforced cencrete (SRC) composite columns are tested under eccentric loading conditions.Effects of concrete strength, slenderness of columns and eccentricity of the axial load are studied. The load-carrying capacity is reduced with increased slenderness ratio and eccentricity. Concrete strength has no obvious influence on eccentrically loaded columns. Then, a nonlinear numerical method of pin-ended slender columns is also presented. This method is applicable for determining the material failure load or buckling failure load of a slender steel reinforced concrete composite column. In this method both material and geometric nonlinearities are taken into account. The results of numerical analysis accord well with the test results. The test results are also compared with the results predicted by ACI318-05 and the China Specifications.     

硒-高分子复合微球的微凝胶模板法制备研究

采用反相悬浮聚合法合成了聚丙烯酰胺(PAM)高分子微凝胶,以其为模板,在室温条件下,以硒代硫酸钠(Na2SeSO3)作为硒源,制备得到了Se-PAM无机-有机复合微球材料,利用扫描电子显微镜(SEM)、X射线衍射(XRD)等手段对复合微球的形貌、无机物硒晶形结构等进行了表征。     

外包钢-混凝土连续组合梁的负弯矩极限承载力(英文)

对2根外包钢-混凝土连续梁试件进行了静力加载实验研究与承栽力分析.测量并分析了试件的荷栽-挠度及荷载-应变关系曲线.结果表明:外包钢-混凝土组合梁负弯矩区钢筋和外包钢梁通过抗剪连接措施能有效地共同工作,整体工作性能良好.在承栽能力极限状态,负弯矩和正弯矩最大截面的塑性应变均充分发展,并形成比较理想的塑性铰.随着配筋率的提高,组合梁受弯承栽力明显提高,而延性和转动能力相应降低.在试验数据基础上,给出了外包钢-混凝土组合梁在负弯矩区极限受弯承载力的计算公式,计算结果与实验结果吻合良好.     

煤巷锚索支护机理分析及其应用

结合高地应力、复合顶板等复杂地质条件,研究深井条件下煤巷锚索采用小孔径、施加高预应力的结构形式和施工工艺,工程实践表明,该技术是解决深井高应力软岩巷道、大断面交岔点等支护难题的有效途径。     

Preparation and characterization of TiO2/expanded graphite

In order to obtain anatase TiO2/expanded graphite with high expansion volume, titania gel was introduced to expandable graphite surface by sol-gel process, and then the composite was expanded and calcined at high temperature. The samples were analysed by using scanning electron microscope (SEM), X-ray diffraction(XRD), energy disperse spectroscopy(EDS), and differential scanning calorimetry(DSC). The optimal conditions for preparation are as follows: the molar ratio of tetrabutyl orthotitanate to triethanolamine is 1∶0.4, and the calcination and expansion temperature is in the range of 650-750 °C. Under such conditions, the expansion volume of composites could reach 98 mL/g, and the mass loss ratio is less than 5%. The analysis shows that lower temperature and smaller particle size of graphite are helpful to the formation of anatase-type of TiO2, but larger particle size will lead to lower mass loss ratio, and higher temperature and larger particle size will lead to higher expansion volume.     

二氧化硅增强石英纤维复合材料高温电性能温度特性

运用静电学理论,建立计算二氧化硅增强石英纤维复合材料介电参数的经验模型,实现材料高温介电性能的温度特性模拟,并对材料介电性能的变化规律作出预测.模拟结果与实际结果基本相符,为材料改性提供依据.     

CCId对国内数字出版产业调整的影响及策略研究

从国内数字出版业呈现出一些新的特点及其一些发展中的问题入手,介绍新闻出版总署提出的数字复合出版工程,这是我国出版产业的重组、整合、调整的新战略。这其中中文内容唯一标识符(CCId)是在整个数字复合出版整个流程中的关键因素,论文从
经营模式、内部管理模式、盈利模式等方面讨论CCID对国内数字出版具有重要影响,最后从出版源头、在线支付中的版权转移、规模化与多元化经营、专家审稿与读者在线评论、内容加工颗粒度变小而带来的新的利润模式等角度为数字出版产业调整提供一些策略。     

科研机构总量评价指标的改进研究——基于规模、质量、均衡的视角

为更加客观全面地对科研机构进行评价,从规模、质量、均衡的视角提出一种新的总量指标数据预处理方法--总量指标复合法,其思路是首先根据总量指标计算出人均指标和均衡指标,然后再将三者加权汇总成为一个复合指标,最后进行科研机构的评价。以地区科研产出评价为例,采用层次分析法进行实证,比较该方法与传统方法评价结果的区别,认为总量指标复合法应该和相对指标选取结合使用,还对总量指标复合法的适用条件进行讨论。     

Morphology evolution of two-phase Cu-Ag alloys under different conditions

Cu-Ag filamentary microcomposites with different Ag contents were prepared by cold drawing and intermediate heat treatments. The microstructure characterization and filamentary distribution were observed for two-phase alloys under different conditions. The effect of heavy drawing strain on the microstructure evolution of Cu-Ag alloys was investigated. The results show that the microstructure components consist of Cu dendrites, eutectic colonies and secondary Ag precipitates in the alloys containing 6%-24% （mass fraction） Ag. With the increase in Ag content, the eutectic colonies in the microstructure increase and gradually change into a continuous net-like distribution. The Cu dendrites, eutectic colonies and secondary Ag precipitates are elongated in an axial direction and developed into the composite filamentary structure during cold drawing deformation. The eutectic colonies tend to evolve into filamentary bundles. The filamentary diameters decrease with the increase in drawing strain degree for the two-phase alloys, in particular for the alloys with low Ag content. The reduction in filamentary diameters becomes slow once the drawing strain has exceeded a certain level.