Bio-Inspired Aggregation Control of Carbon Nanotubes for Ultra-Strong Composites

High performance nanocomposites require well dispersion and high alignment of the nanometer-sized components, at a high mass or volume fraction as well. However, the road towards such composite structure is severely hindered due to the easy aggregation of these nanometer-sized components. Here we demonstrate a big step to approach the ideal composite structure for carbon nanotube (CNT) where all the CNTs were highly packed, aligned, and unaggregated, with the impregnated polymers acting as interfacial adhesions and mortars to build up the composite structure. The strategy was based on a bio-inspired aggregation control to limit the CNT aggregation to be sub 20--50 nm, a dimension determined by the CNT growth. After being stretched with full structural relaxation in a multi-step way, the CNT/polymer (bismaleimide) composite yielded super-high tensile strengths up to 6.27--6.94 GPa, more than 100% higher than those of carbon fiber/epoxy composites, and toughnesses up to 117--192 MPa. We anticipate that the present study can be generalized for developing multifunctional and smart nanocomposites where all the surfaces of nanometer-sized components can take part in shear transfer of mechanical, thermal, and electrical signals

银行业金融机构市场退出机制的缺陷及完善

本文认为在金融业全面开放背景下,部分银行业金融机构被淘汰出局将不可避免。银行业金融机构市场退出机制担负斩断金融风险传导和危机扩散之重任,关系金融体系安全乃至国家经济安全问题。然而,当前我国银行业金融机构市场退出机制建设尚存诸多缺陷,亟需加以完善。国家社会科学基金项目《公司治理法律制度研究》(批准号:06BFX030)的阶段性成

化学气相沉积SiC–B_xC涂层在高温模拟环境中的微观结构

将化学气相沉积在石墨基片上的SiC-BxC复合涂层在O2(8kPa)/H2O(14kPa)/Ar(78kPa)的模拟气氛中,分别加热到700,1000℃和1200℃处理10h。利用扫描电镜、X射线衍射、能谱分析、显微Raman和Fourier变换红外光谱仪研究其微观结构。结果表明:复合涂层中的BxC层在700～1000℃的模拟环境中会被完全氧化成B2O3和H3BO3;在1000～1200℃的模拟环境中,BxC层的氧化产物迅速挥发。经高温模拟环境处理后,复合涂层中生成了硼硅酸盐玻璃,且各氧化产物和SiC层的结晶度随处理温度的升高而下降。基于微观分析结果,对SiC-BxC复合涂层的自愈合抗氧化性能进行了分析

Dynamic Selection of Materialized Views of Multi Dimensional Data with a Multi-Users and Multi Windows Method

多维视图动态维护是数据仓库领域当前研究的一个热点 随着数据仓库的普及 ,将有越来越多的各种类型的用户使用OLAP工具满足各自特定的分析需求 现有的各种视图选择方法没有考虑不同类型用户的特点 ,从而存在一些缺陷 提出多用户多窗口方法 ,充分考虑用户的差异 ,利用单个用户在查询时的相对有规律性 ,为用户划分级别 ,并为每个用户设置相应级别的用户视图窗口 ,从而合理地利用了系统有限的资源 ,提高了查询响应速度 ,也保证了特殊用户对查询性能的特殊需求 ;给出了相关的定义和MUMW算法 ,并阐述了多用户多窗口方法的优点Dynamic selection of materialized views of multi dimensional data is one of the most researched aspects in the field of data warehouse; With the increasing use of data warehouse, there will be accordingly more and more different kinds of users making use of OLAP tools to complete their analytical work; The existing methods being used to select views do not take into account the characteristic of various kinds of users, and therefore have some defects; A multi users and multi windows method is presented here, which considers the disparity among various users and makes use of the rule of the users' queries In the method, all users are divided into three groups with different grade and each user is accordingly endowed with user view window of certain grade Such method leads to the reasonable use of the limited space resource and also speeds up the response of query, which stipulates satisfying some special needs of certain user; Some related conceptions and MUMW algorithm are also put forward here, and at the same time, the advantages of this method are described福建省自然科学基金项目 (A0 3 10 0 0 8);; 福建省高新技术研究开放计划重点项目 ( 2 0 0 3H0 43

Dynamic Selection of Materialized Views of Multi-Dimensional Data with a Multi-Users and Multi-Windows Method

多维视图动态维护是数据仓库领域当前研究的一个热点 随着数据仓库的普及 ,将有越来越多的各种类型的用户使用OLAP工具满足各自特定的分析需求 现有的各种视图选择方法没有考虑不同类型用户的特点 ,从而存在一些缺陷 提出多用户多窗口方法 ,充分考虑用户的差异 ,利用单个用户在查询时的相对有规律性 ,为用户划分级别 ,并为每个用户设置相应级别的用户视图窗口 ,从而合理地利用了系统有限的资源 ,提高了查询响应速度 ,也保证了特殊用户对查询性能的特殊需求 ;给出了相关的定义和MUMW算法 ,并阐述了多用户多窗口方法的优点。Dynamic selection of materialized views of multi-dimensional data is one of the most researched aspects in the field of data warehouse; With the increasing use of data warehouse, there will be accordingly more and more different kinds of users making use of OLAP tools to complete their analytical work; The existing met hods being used to select views do not take into ccount the characteristic of various kinds of users, and therefore have some defects; A multi-users and multi-windows method is presented here, which considerst he disparity among various users and makes use of the rule of the users’queries1 In the method,all users are divided into three group swith different grade and each user is accordingly endowed with user view window of certain grade. Such met hod leads to the reasonable use of the limited space resource and also speeds up the response of query, which stipulates satisfying some special needs of certain user; Some related conceptions and MUMW algorithm are also put forward here, and at the same time , the advantages of this method are described.福建省自然科学基金项目(A0310008);福建省高新技术研究开放计划重点项目(2003H043

闽南沿海木麻黄基干林带的防风效应

为深入认识沿海木麻黄基干林带内外风速变化规律和空间分布,从2006年11月到2007年3月在东山岛木麻黄基干林带内外多个测点进行了风速测定。结果表明:基干林带风速变化规律为:林内下降和林外上升的开口向上的抛物线状;风速空间分布为林带内下凹、林带后上升的平滑曲面,中间出现一些小的凸出或下凹的斑快。基干林带内等值线比较平直均匀,林带后比较弯曲且分布不均匀。国家“十一五”科技支撑计划项目(2006BAD03A14-01);; 福建省重大科技专项(2006NZ0001-2

福建东山木麻黄基干林内的风速变化规律

从2006年11月到2007年3月在东山岛对不同发育阶段木麻黄基干林带内多个测点进行了风速测定,以探讨基干林带内部风速变化规律和空间分布。结果表明:木麻黄基干林带内风速呈逐渐下降趋势,各发育阶段林带内5h处风速小于2m/s,10h处低于1m/s。空间分布为平滑的下降曲面,局部有凸起和下凹。等值线比较平直和均匀,没有形成闭合区域。国家“十一五”科技支撑计划项目(2006BAD03A14-01);; 福建省重大科技专项(2006NZ0001-2

闽南肝癌高发区肝细胞癌与HBV复制的相关性分析

目的分析闽南肝癌高发区乙型肝炎病毒 (HBV)复制与原发性肝细胞癌 (PHCC)的关系。方法用实时荧光定量聚合酶链反应 (PQ- PCR)技术测定 6 1例 PHCC患者、40 7例不同病程的 HBV感染者及 17例健康人血清中 HBV DNA的含量 ,对照分析 HBV标志物 (HBVM) ,同时检测 PHCC患者抗 - HCV- Ig G和 HCV RNA。结果PHCC组 HBV DNA阳性率高达 80 .3% (49/ 6 1) ,高于其他肝病组 ,差异具显著性 (P<0 .0 2 ) ,HBV DNA含量各组间差异无显著性。PHCC组抗 - HCV- Ig G和 HVC RNA阳性率为 0。结论闽南肝癌高发区 PHCC患者 HBV DNA阳性率较高 ,HBV感染并持续复制 ,可能是该地区 PHCC的主要致病因