By combining the strong and light carbon fibers （CFs） with polymers, composite materials with extraordinary mechanical properties are achieved. However, the mechanical properties of the as-prepared CF-reinforced pol...By combining the strong and light carbon fibers （CFs） with polymers, composite materials with extraordinary mechanical properties are achieved. However, the mechanical properties of the as-prepared CF-reinforced polymer composites can not satisfy the applications in certain fields, especially for the poor interactions between CFs and the polymers. To enhance the mechanical properties of composite materials, a solid phase grafting method has been developed to improve the adhesion forces between CFs and the polymer, by modifying the surfaces of CFs. The effects of the reaction temperature, reaction time, as well as the dosage of the initiator and maleic anhydride （MAH） on the grafting efficiency have been investigated systematically. The structure and the surface chemistry of functionalized CFs have been characterized by Fourier Transform Infrared （FT-IR）, Scanning Electron Microscope （SEM）, X-ray Photoelectron Spectroscopy （XPS）, Thermogravimetric （TG）, and contact angle test. All of these results demonstrate that MAH is grafted onto the surface of CFs successfully by the solid phase grafting method. The MAH grafted CFs significantly improve its wettability, which further improves the interfacial adhesion between CFs and the polymeric matrix. The optimal reaction conditions are determined, such as the MAH/CF molar ratio, the dosage of initiator, the reaction temperature and the reaction time to be 3/1, 2%, 90℃ and 4 h, respectively. These attractive interracial characteristics of modified CFs suggest that the method proposed herein is a novel and efficient approach to develop CF-reinforced polymer composites with outstanding mechanical properties for cutting-edge industrial applications.展开更多
International factoring is an alternative method of international settlement and financing provided by factors to exporters or importers. In terms of its particular advantages, international factoring is now widely us...International factoring is an alternative method of international settlement and financing provided by factors to exporters or importers. In terms of its particular advantages, international factoring is now widely used in effectively improving cash flow, avoiding bad debts, reducing operation expenses and increasing financing capital. This article starts with the background of international factoring, then goes deep into the meaning and relative merits of it. Finally, it is attempting to stress the significant use of international factoring again.展开更多
In this work we are presenting a modified Coulomb potential function to describe the interaction between two micro-scopic electric charges. In particular, concerning the interaction between the proton and the electron...In this work we are presenting a modified Coulomb potential function to describe the interaction between two micro-scopic electric charges. In particular, concerning the interaction between the proton and the electron in the hydrogen atom. The modified potential function is the product of the classical Coulomb potential and an oscillatory function dependent on a quantized phase factor. The oscillatory function picks up only selected points along the Coulomb potential, creating potential wells and barriers around the nucleus of the atom. The new potential reveals us new features of the hydrogen atom. Searching for a manner to determine the phase factor, we are using the concept of the de Broglie particle wavelike behavior and the quantum analogue of the virial theorem for describing the bound motion of a particle in a central force field. This procedure is a kind of feedback action, where we are making use of well established concepts of the quantum mechanics aiming to determine the phase factor of the new interaction potential.展开更多
基金Supported by the Science and Technology Plan Projects of Fujian Province(No.2012H6008)
文摘By combining the strong and light carbon fibers （CFs） with polymers, composite materials with extraordinary mechanical properties are achieved. However, the mechanical properties of the as-prepared CF-reinforced polymer composites can not satisfy the applications in certain fields, especially for the poor interactions between CFs and the polymers. To enhance the mechanical properties of composite materials, a solid phase grafting method has been developed to improve the adhesion forces between CFs and the polymer, by modifying the surfaces of CFs. The effects of the reaction temperature, reaction time, as well as the dosage of the initiator and maleic anhydride （MAH） on the grafting efficiency have been investigated systematically. The structure and the surface chemistry of functionalized CFs have been characterized by Fourier Transform Infrared （FT-IR）, Scanning Electron Microscope （SEM）, X-ray Photoelectron Spectroscopy （XPS）, Thermogravimetric （TG）, and contact angle test. All of these results demonstrate that MAH is grafted onto the surface of CFs successfully by the solid phase grafting method. The MAH grafted CFs significantly improve its wettability, which further improves the interfacial adhesion between CFs and the polymeric matrix. The optimal reaction conditions are determined, such as the MAH/CF molar ratio, the dosage of initiator, the reaction temperature and the reaction time to be 3/1, 2%, 90℃ and 4 h, respectively. These attractive interracial characteristics of modified CFs suggest that the method proposed herein is a novel and efficient approach to develop CF-reinforced polymer composites with outstanding mechanical properties for cutting-edge industrial applications.
文摘International factoring is an alternative method of international settlement and financing provided by factors to exporters or importers. In terms of its particular advantages, international factoring is now widely used in effectively improving cash flow, avoiding bad debts, reducing operation expenses and increasing financing capital. This article starts with the background of international factoring, then goes deep into the meaning and relative merits of it. Finally, it is attempting to stress the significant use of international factoring again.
文摘In this work we are presenting a modified Coulomb potential function to describe the interaction between two micro-scopic electric charges. In particular, concerning the interaction between the proton and the electron in the hydrogen atom. The modified potential function is the product of the classical Coulomb potential and an oscillatory function dependent on a quantized phase factor. The oscillatory function picks up only selected points along the Coulomb potential, creating potential wells and barriers around the nucleus of the atom. The new potential reveals us new features of the hydrogen atom. Searching for a manner to determine the phase factor, we are using the concept of the de Broglie particle wavelike behavior and the quantum analogue of the virial theorem for describing the bound motion of a particle in a central force field. This procedure is a kind of feedback action, where we are making use of well established concepts of the quantum mechanics aiming to determine the phase factor of the new interaction potential.
