Fabrication of hollow porous PLGA microspheres for controlled protein release and promotion of cell compatibility

This letter reports on the fabrication of hollow,porous and non-porous poly(D,L-lactide-co-glycolide) (PLGA) microspheres(MSs) for the controlled release of protein and promotion of cell compatibility of tough hydrogels.PLGA MSs with different structures were prepared with modified double emulsion methods,using bovine serum albumin(BSA) as a porogen during emulsification.The release of the residual BSA from PLGA MSs was investigated as a function of the MS structure.The hollow PLGA MSs show a faster protein release than the porous MSs,while the non-porous MSs have the slowest protein release.Compositing the PLGA MSs with poly(vinyl alcohol)(PVA) hydrogels promoted chondrocyte adhesion and proliferation on the hydrogels.     

LaAlO3基电解质与阳极材料的化学相容性及电化学性能

采用甘氨酸-硝酸盐法(GNP)合成La_0.90Sr_0.10Al_0.97Mg_0.03O_3-δ (LSAM)粉体, 成型后经1500 °C、5 h 烧结的样品, 900 °C时其电导率为1.11×10^-2 S·cm^-1. 利用X射线衍射(XRD)、扫描电镜/X 射线能谱分析(SEM/EDX)和交流阻抗技术等表征手段研究NiO-Ce_0.9Gd_0.1O_1.95 (Ni-GDC)、Sr_0.88Y_0.08TiO₃ (SYT)和La_0.75Sr_0.25Cr_0.5Mn_0.5O₃(LSCM)三种阳极材料与LSAM电解质的化学相容性. 结果表明, SYT 和LSCM与LSAM的化学相容性欠佳,SYT中的Sr²⁺和Ti⁴⁺向LSAM晶格的扩散明显, LSCM中的Mn³⁺和Cr³⁺向LSAM晶格的扩散显著; 而Ni-GDC与LSAM具有良好的化学相容性, 在1300 °C下两材料间阳离子的相互扩散作用极小. 800 °C时Ni-GDC的比表面极化电阻(RASP)值为5.12 Ω·cm². LSAM 电解质(厚度为550 μm)支撑的Ni-GDC/GDC/LSAM/GDC/LSF(La_0.75Sr_0.25FeO₃)单电池, 在800 °C时电池的开路电压为0.925 V, 最大功率密度为19.5 mW·cm^-2.     

Compatibility Study of Blends of Acrylic Rubber (ACM), Poly(ethyleneterephalate) (PET), and Liquid Crystalline Polymer (LCP)

The ternary blends of acrylate rubber (ACM), poly(ethyleneterephalate) (PET), and liquid crystalline polymer (LCP) were prepared by varying the amount of LCP, but fixing the ratio of ACM and PET using melt mixing procedure. The compatibility behavior of these blends was investigated with infrared spectroscopy (IR), differential scanning calorimetry (DSC), and dynamic mechanical analyzer (DMA). The IR results revealed the significant interaction between the blend components. Glass transition temperature (T_g) and melting temperature (T_m) of the blends were affected depending on the LCP weight percent in the ACM/PET, respectively. This further suggests the strong interfacial interactions between the blend components. In the presence of ACM, the nucleating effect of LCP was more pronounced for the PET. The thermogravimetric (TGA) study shows the improved thermal stability of the blends.     

交换环的M-赋值与序的相容性

在有单位元的交换环上,引入了M-赋值与序之间的相容性,由此获得一些有关M-赋值与序相容的结果.结果可看作Manis赋值和形式有限V-赋值的相关结果的推广.     

机载多天线系统电磁兼容性研究

为了在有限计算机资源条件下快速解决机载平台中多天线系统的电磁兼容(EMC)问题,基于电场积分方程(EFIE),实现自动分层的多层快速多极子方法(MLFMA).针对天线问的近场耦合特性,采用任意天线间的隔离度代替传统隔离度,使得隔离度计算结果更加合理.同时采用BiCGStab(l)结合近场预条件方法进行求解,进一步提高MLFMA的综合效率.最后实例计算并分析波音747飞机模型上多根超短波天线的辐射方向图和宽频带内天线间的隔离度.数值结果表明方法准确有效.     

Blends Based on Polystyrene and Statistical Aromatic Copolycarbonates

The compatibility of polystyrene (PS) with aromatic copolycarbonates containing bisphenol A (BPA) and tetramethyl bisphenol A (TMBPA) was investigated. The simple prevision scheme developed by Sonja Krause was employed to evaluate the effect of the copolymer molecular structure on the miscibility with polystyrene. These prevision data were used to select copolycarbonates of potential interest. Statistical copolycarbonates (CPC) containing different BPA/TMBPA molar ratios were synthesised by polycondensation reaction between a mixture of the two monomers and phosgene. PS/polycarbonates blends, prepared by casting from chloroform solution, were studied with differential scanning calorimetry and optical microscopy to evaluate the components compatibility, which increases with the TMBPA copolymer content.     

高安全锂离子电池复合集流体的界面强化

面向高能量密度电池的高比容量三元正极材料的应用，使锂离子电池更容易发生热失控，这不仅降低了其安全性,也限制了锂离子电池的进一步发展。如何在提高能量密度的同时保证电池的安全性是亟待解决的问题。以绝缘高分子薄膜为支撑基材，两侧沉积金属层得到了具有夹芯结构的铝复合集流体能有效保证电池在针刺条件下的安全性，且更轻的复合集流体的使用能进一步提高电池能量密度。但高分子基材与铝金属层之间界面结合力较差，这会导致复合集流体在高温电解液浸泡中发生脱层现象，从而影响其在电池中的使用。本研究采用聚对苯二甲酸乙二醇酯(PET)作为支撑基材，通过在铝金属镀层与高分子基材之间引入氧化物中间层，有效地增强了金属与高分子基材之间的界面结合力，提升复合集流体的电解液兼容性。此外，复合集流体良好的机械性能使其能很好地兼容现有的电池制备技术，利用其制备的软包电池表现出与使用传统铝箔为集流体的电池相当的电化学性能。进一步的针刺测试表明，复合集流体能有效阻止锂电池在针刺过程中的热失控，显著改善了电池的安全性能。