The article describes the layered model of physical network and information security, and the establishment of the mobile Internet’s security framework based on its network architecture. The mobile Internet has three...The article describes the layered model of physical network and information security, and the establishment of the mobile Internet’s security framework based on its network architecture. The mobile Internet has three parts, i.e. terminal, network and service system, each of which can be studied in four layers of the network and information security, namely, the equipment/environment security layer, the service and application security layer, the information security layer and the information content security layer.展开更多
以对苯二甲酸(H_2BDC)为配体、乙酸钴为Co源、水作溶剂,通过共沉淀法合成了金属有机框架材料(Co-BDC M OFs);以其为前驱体分别在乙炔和氩气氛下采用化学气相沉积法制备了核壳结构Co@C催化剂。结合XRD、氮吸附、SEM、TEM、XPS、TGA和Rama...以对苯二甲酸(H_2BDC)为配体、乙酸钴为Co源、水作溶剂,通过共沉淀法合成了金属有机框架材料(Co-BDC M OFs);以其为前驱体分别在乙炔和氩气氛下采用化学气相沉积法制备了核壳结构Co@C催化剂。结合XRD、氮吸附、SEM、TEM、XPS、TGA和Raman光谱等手段对Co@C催化剂的结构和组成进行了表征,考察了该催化剂在费托合成反应中的活性及稳定性。结果表明,炭化气氛对炭层结构的石墨化程度有较大影响,而对金属Co核的物相结构和粒径影响较小;乙炔气氛有助于形成多孔的石墨炭壳,从而促进烃链的生长,Co@C-C_2H_2催化剂上的C_(5+)烃产物选择性高达82. 66%,反应过程中催化剂物相由单相金属Co转变为金属Co与Co_2C的混合相,且无失活现象发生,表明Co_2C具有较高的费托反应催化活性。展开更多
基金supported by the National HighTechnology Research and Development Programof China ("863" Program) under Grant No.2008AA01A204
文摘The article describes the layered model of physical network and information security, and the establishment of the mobile Internet’s security framework based on its network architecture. The mobile Internet has three parts, i.e. terminal, network and service system, each of which can be studied in four layers of the network and information security, namely, the equipment/environment security layer, the service and application security layer, the information security layer and the information content security layer.
文摘以对苯二甲酸(H_2BDC)为配体、乙酸钴为Co源、水作溶剂,通过共沉淀法合成了金属有机框架材料(Co-BDC M OFs);以其为前驱体分别在乙炔和氩气氛下采用化学气相沉积法制备了核壳结构Co@C催化剂。结合XRD、氮吸附、SEM、TEM、XPS、TGA和Raman光谱等手段对Co@C催化剂的结构和组成进行了表征,考察了该催化剂在费托合成反应中的活性及稳定性。结果表明,炭化气氛对炭层结构的石墨化程度有较大影响,而对金属Co核的物相结构和粒径影响较小;乙炔气氛有助于形成多孔的石墨炭壳,从而促进烃链的生长,Co@C-C_2H_2催化剂上的C_(5+)烃产物选择性高达82. 66%,反应过程中催化剂物相由单相金属Co转变为金属Co与Co_2C的混合相,且无失活现象发生,表明Co_2C具有较高的费托反应催化活性。
