High-Performance Fiber Compound Material to be Industrialized

Chinese top planner-State Development and Reform Commission,has decided to organize and coordinate an implementation of a special project for high tech industrialization of fiber-reinforced compound materials in 2008 up to 2009.The decision has recently been issued in its national circular(doc. 3177,Yr.2007)to call for local enterprises to apply for this special project support.

Biocompatibility of Compounds of Extracellular Matrix and Thermally Reversible Hydrogel

A new scaffold material composed of extracellular matrix （ECM） and thermal sensitive hydrogel （HG）, and evaluated its biocompatibility were investigated. We cultured bladder smooth muscle cells with this compound material, and then observed with phase contrast microscopy and scanning electron microscope （SEM） to assess the cell growth and morphology. The cell adhesion and proliferation were detected with MTT assay and cell count. Results show the ECM/HG compounds appeared as a net-like and red-stained construction with enough meshes and without any cellular fragments. 6 h after implantation, cells were observed adhere on the compounds and extend spurious along the fibers 12 h later. Under SEM even some ECM was observed to be secreted. MTT assay shows there was obvious statistic difference among 3 groups （P〈0.05）. ECM/HG compound materials show a good biocompatibility, which confirms that it would be an ideal tissue engineering scaffolds.

The structural basis of oscillation damping in plant stems-biomechanics and biomimetics

Oscillations and their damping were investigated for plant stems of Cyperus alternifolius L., Equisetum hyemale L., Equisetum fluviatile L., Juncus effuses L., Stipa gigantea Link, and Thamnocalamus spathaceus (Franch.) Soderstr. With the exception of T. spathaceus, mechanical damping of the oscillation of individual plant stems, even without side organs, leaves or inflorescences, is quite effective. Our experiments support the hypothesis that embedding stiff sclerenchymatous elements in a more compliant parenchymatous matrix provides the structural basis for the dissipation of mechanical energy in the plant stem. As an application the naturally occurring structures were mimicked in a compound material made from hemp fabrics em- bedded in polyurethane foam, cured under pressure. Like its natural model it shows plastic deformability and viscoelastic be- haviour. In particular the material is characterized by a remarkably high shock absorption capacity even for high impact loads.

Design and fabrication of one-dimensional focusing X-ray compound lens with A1 material

A method based on Fourier spectrum analysis for predicting the performances of the X-ray compound lenses is briefly introduced, the theoretical result obtained is the same as that of Fresnel-Kirchhoff approach. A kind of technique named moulding is developed for fabricating the one-dimensional (1D) compound X-ray lens with Al material and the fabrication process is presented. In addition, a two-time coating method is used to improve the numerical apertures of the compound lenses. Furthermore, the focusing performance of the Al compound X-ray lens under the high energy X-rays is measured.

A study on the minority carrier diffusion length in n-type GaN films

The minority carrier diffusion length of n-type GaN fdms grown by metalorganic chemical vapor deposition （MOCVD） has been studied by measuring the surface photovoltaic （PV） spectra. It was found that the minority carrier diffusion length of undoped n-type GaN is considerably larger than that in lightly Si-doped GaN. However, the data suggested that the dislocation and electron concentration appear not to be responsible for the minority cartier diffusion length. It is suggested that Si doping plays an important role in decreasing the minority carrier diffusion length.