Phonon-assisted intersubband transitions in wurtziteGaN/InxGal_xN quantum wells

A detailed numerical calculation on the phonon-assisted intersubband transition rates of electrons in wurtzite GaN/In x Ga 1 x N quantum wells is presented. The quantum-confined Stark effect, induced by the built-in electric field, and the ternary mixed crystal effect are considered. The electron states are obtained by iteratively solving the coupled Schrdinger and Poisson equations. The dispersion properties of each type of phonon modes are considered in the derivation of Fermi’s golden rule to evaluate the transition rates. It is indicated that the interface and half-space phonon scattering play an important role in the process of 1-2 radiative transition. The transition rate is also greatly reduced by the built-in electric field. This work can be helpful for the structural design and simulation of new semiconductor lasers.     

Preparation of hydrogenated natural rubber with nanomatrix structure

Hydrogenated deproteinized natural rubber (HDPNR) with nanomatrix structure was prepared through graft‐copolymerization of acrylonitrile and styrene onto HDPNR particle in latex stage. Structural characterization of the resulting materials through nuclear magnetic resonance and Fourier‐transform infrared spectroscopy confirmed that acrylonitrile and styrene were grafted onto HDPNR. The weather resistance, thermal properties, mechanical properties, storage modulus, and morphology of the resulting materials were investigated in comparison with those of HDPNR. The obtained result indicated that the graft‐copolymerization of HDPNR with hydrogenation conversion of 60 mol% attained the highest grafting efficiency. Thermal resistance and storage modulus of HDPNR‐graft‐poly (styrene‐co‐acrylonitrile) (HDPNR‐g‐SAN) were superior compared with those of HDPNR and deproteinized natural rubber. This was attributed to the nanomatrix formed in HDPNR‐g‐SAN, which was confirmed through a transmission electron microscope. Ribbed smoked sheet natural rubber exhibited the outstanding mechanical properties and weather resistance when it was mixed with HDPNR‐g‐SAN.     

Uniqueness Theorem for Holomorphic Mappings on Annuli Sharing Few Hyperplanes

Ukrainian Mathematical Journal - We prove a uniqueness theorem for linearly nondegenerate holomorphic mappings from an annulus to a complex projective space ℙn(ℂ) with different...     

Spanning trees whose reducible stems have a few branch vertices

Czechoslovak Mathematical Journal - Let T be a tree. Then a vertex of T with degree one is a leaf of T and a vertex of degree at least three is a branch vertex of T. The set of leaves of T is...     

DNA thin film coated optical fiber biosensor

We present a simple but highly sensitive biotinylated DNA double crossover thin film coated fiber optic reflectance biosensor (DTF FORS) for the detection of streptavidin aerosols as a building block towards sensing bio-aerosols. The DNA double crossover lattice with biotin was dropped on the polymer optical fiber end face to prepare DNA Thin Film. The streptavidin aerosols were prepared using conventional aerosol technology. The DTF FORS response to streptavidin aerosol was few seconds and the sensor repeatability for air and streptavidin aerosol was found to be excellent. The presented FORS sensing approach, where the film can be changed on the end face of the optical fiber, is expected to detect atmospheric bio-aerosols with great sensitivity and effective specificity.     

玄武岩/Kevlar纤维布填充防护结构撞击极限及损伤特性

为了研究玄武岩/Kevlar纤维布填充防护结构的撞击极限和损伤特性,采用非火药驱动二级轻气炮进行超高速撞击实验,拟合撞击极限曲线,并与Nextel/Kevlar填充防护结构及三层铝防护结构进行比较。结果表明:玄武岩/Kevlar填充防护结构具有和Nextel/Kevlar填充防护结构类似的防护效果,防护性能优于三层铝防护结构。进一步研究填充防护结构铝合金防护屏、纤维布填充层及铝合金舱壁的损伤形式,分析了造成防护屏、填充层与舱壁不同损伤形貌的原因,探索了玄武岩/Kevlar纤维布填充防护结构的防护机理,得出玄武岩纤维布填充层使弹丸碎化,而Kevlar填充层消耗、吸收和分散弹丸或碎片云的能量。     

智能水凝胶双抗癌药物控释体系

近年来,基于联合用药策略的双药物控释体系的研究为降低抗癌药物毒性和提高疗效提供了有效途径。水凝胶作为一类高临床应用价值的药物载体,在药物控释方面具有广泛的应用前景。癌症是危害人类健康和生命的疾病之一,当人体内正常细胞发生癌变后,癌变细胞周围会发生一些显著的变化。因此,根据肿瘤细胞与正常细胞在体内环境及体外环境的差异,发展了多种智能型水凝胶双抗癌药物控释载体。它能够在感知外界因素的刺激下发生内部结构的变化,从而实现对药物的可控释放。与此同时,随着新的治疗手段的兴起和更多抗癌作用靶点的发现,水凝胶载体也成功实现了化学药物和生物治疗因子的同时负载和可控释放。本文将从不同智能型水凝胶载体如何负载、控释双抗癌药物及水凝胶药物载体中药物的组合方式两方面综述智能型水凝胶双抗癌药物控释体系最新研究进展,并展望其发展前景。