聚己内酯（PCL）多孔亚微米纤维的制备

以DMF、丙酮、二氯甲烷和丙酮／二氯甲烷为溶剂,通过静电纺丝方法制备PCL亚微米纤维．通过SEM观察纤维形貌及其孔径大小,通过N2吸附一脱附曲线计算纤维的比表面积,通过拉伸实验测试纤维的力学性能．实验结果表明：以单-DMF、丙酮为溶剂制备得到表面光滑无孔亚微米纤维．而以二氯甲烷为溶剂无法制备连续的纤维．以丙酮／二氯甲烷为溶剂制备得到直径为0．86±0．14／μm、孔径大小为65．0±17．5nm,比表面积为21．15m2／g的亚微米纤维．相比较无孔纤维,多孔PCL亚微米纤维的拉伸强度和杨氏模量略有下降,而断裂伸长率有所增加,主要是因为拉伸过程中,多孔纤维发生一定程度的收缩．PCL亚微米纤维表面的多孔结构有利于细胞的黏附与生长,因而有望作为组织工程支架材料．     

排水性沥青路面上中面层层间结合状况研究

通过环氧树脂、SBS改性乳化沥青、SBS改性热沥青和H#桥面防水材料等4种粘结层材料组合试件的剪切试验,对影响排水性路面的行车荷载、温度和水等外部因素进行了研究和分析.试验结果表明,温度升高会造成层间结合能力的降低,层间剪切强度与温度之间的关系接近一条对数曲线.在实际路面中,行车荷载作用中心区域下的剪切强度较其他部位要小.冻融和饱水等水损害都明显地降低了路面抗剪强度,破坏了上中面层间的层间结合.荷载、温度和水等因素的作用会对层间结合状况产生一定的不利影响,需要通过优选粘结层材料来提高排水性路面的耐久性.     

刺榆的木材解剖学研究

刺榆为榆科植物，通过木材解剖学研究，发现其为环孔材，射线为同形单列及多列。     

Structure and Oxygen Sensing Properties of TiO2 Porous Semiconductor Thin Films

The TiO2thin films have attracted attention be-cause of their remarkable optical and electronic prop-erties[1,2]. They are used in a wide variety of applica-tions such as photocatalysts[3,4], gas sensors[5,6]andsolar cells. Titania exists mainly in three …     

多孔介质发动机详细反应动力学模型

应用Chemkin化学动力学软件包中的Senkin模块模拟了正庚烷在多孔介质发动机中的燃烧过程．通过修改Senkin程序,结合了Woschni传热模型和多孔介质换热模型,并在正庚烷详细氧化机理中加入氮氧化物的生成机理,将此程序纳入发动机燃烧的零维单区模型．对多种工况参数进行计算,讨论了运行参数对发动机性能的影响．当进气温度、压缩比增大,或过量空气系数降低时,多孔介质发动机着火时刻会明显提前．结果表明：多孔介质对混合气具有预热作用可强化发动机的点火燃烧,多孔介质的初始温度是决定压燃点火的决定性因素．     

多孔阳极氧化铝为模板电沉积制备纳米线的研究进展

多孔阳极氧化铝为模板制备纳米结构材料具有独特的优越性，颇受人们的关注，近年来获得了深入的研究．介绍了以多孔阳极氧化铝为模板采用电化学沉积方法制备各种有序纳米线阵列结构材料的最新研究进展，其中包括多孔氧化铝模板的制备和电沉积制备纳米材料的工艺及方法，同时展望了纳米线作为功能材料的应用前景．     

掺铝多孔硅光致发光谱研究

报道了多孔硅掺入杂质铝处理的一种新方法。观测了处理后多孔硅的光致发光谱，其光谱出现了4个与铝杂质能级有关的发光带。我们认为与杂质有关的发光带是由载流子在杂质深能级上复合所致。     

Postsynthetic functionalization of covalent organic frameworks

Covalent organic frameworks (COFs) have been at the forefront of porous-material research in recent years. With predictable structural compositions and controllable functionalities, the structures and properties of COFs could be controlled to achieve targeted materials. On the other hand, the predesigned structure of COFs allows fruitful postsynthetic modifications to introduce new properties and functions. In this review, the postsynthetic functionalizations of COFs are discussed and their impacts towards structural qualities and performances are comparatively elaborated on. The functionalization involves the formation of specific interactions (covalent or coordination/ionic bonds) and chemical reactions (oxidation/reduction reaction) with pendant groups, skeleton and reactive linkages of COFs. The chemical stability and performance of COFs including catalytic activity, storage, sorption and opto-electronic properties might be enhanced by specific postsynthetic functionalization. The generality of these strategies in terms of chemical reactions and the range of suitable COFs places them as a pivotal role for the development of COF-based smart materials.     

Numerical simulation of mechanical behaviors of degradable porous bioceramics with cracks

Hydroxyapatite bioceramics is simulated by using finite element method (FEM).The influences of porosity,hole shape,angle of crack and other parameters on the ceramics are analyzed.The results show that with the increase of the angle between crack and horizontal direction,the stress intensity factor KⅠdecreases gradually,but stress intensity factor K II increases at first and then it decreases.The value of K Ⅱ reaches maximum when the angle between crack and horizontal direction is 45°.KⅠ and K Ⅱ rise with the increase of porosity,and they are almost the same for the circular and hexagonal holes.For elliptical holes,KⅠand KⅡreach maximum when the long axis of ellipse is perpendicular to the loading direction and they reach minimum when the same axis is parallel to the loading direction.Moreover,with the increase of the angle between the long axis and loading direction,KⅠ and KⅡ increase gradually.