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Whan Gun Kim 《应用聚合物科学杂志》2008,107(6):3615-3624
New high‐heat‐resistant photoreactive polymers with cinnamate groups were synthesized by the reaction of cinnamic acid (CA) and epoxy resins. Their photocure properties were investigated with Fourier transform infrared spectroscopy, UV–visible spectroscopy, and thermogravimetric analysis (TGA). Their photocure reaction rates and the extent of reaction conversion increased with the intensity of UV irradiation. To investigate their photocure reaction kinetics, their reaction conversion rates were plotted against reaction conversion so that their photocure reactions could be analyzed in terms of an nth‐order kinetics reaction equation. The YX4000H–CA photoreactive polymer with a biphenyl moiety, which was expected to have strong molecular interactions, showed a lower reaction conversion rate and reaction constant, and the highest reaction conversion rate and reaction constant was observed in XP2030–CA with an optimum cure reaction space and a reduction of molecular interactions compared with the other photoreactive polymers. Thermal stability was studied by observation of the changes in the transmittance of the photocured polymer films upon heating and by measurement of the weight loss with temperature with TGA. These photoreactive polymers showed good thermal properties, with almost no transmittance change in the visible range even after they were heated at 250°C for 1 h, and they exhibited little weight loss up to about 250°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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近年来,公共广播系统在住宅区的建设一直没有受到足够的重视.本文阐述了系统设置的必要性,并以设计者的角度从建筑功能分析、系统设计思想、设备选择及线路敷设等方面介绍了住宅小区中公共广播系统的设计要点. 相似文献
127.
A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power
transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision
positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor
with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic
hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using
an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision
positioning system (100 mm stroke and ±10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance
is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory,
a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The
simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system
with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk
made in dSPACE. 相似文献
128.
Ajna Tóth Kateryna V. Voitko Olga Bakalinska Gennadiy P. Prykhod’ko Imre Bertóti Amelia Martínez-Alonso Juan M.D. Tascón Vladimir M. Gun’ko Krisztina László 《Carbon》2012,50(2):577-585
The poor compatibility of carbon materials with different dispersion media can be overcome by surface functionalization. In this work, multiwall carbon nanotubes (MWCNTs) were doped by oxygen and nitrogen at low concentrations. Morphological and structural changes caused by chemical treatment were monitored using nitrogen, propane and water vapor adsorption measurements. Pore size distribution (PSD) functions derived from various models are compared. The contribution of slit-shaped pores to the total surface area available for adsorbed molecules is smaller than that of cylindrical pores. Functionalities with heteroatoms (both O and N) enhance water adsorption onto MWCNTs. However, no statistical difference is observed between the water adsorption properties of O- or N-containing MWCNTs. 相似文献
129.
Hyunbok Lee Jeihyun Lee Pyungeun Jeon Kwangho Jeong Yeonjin Yi Tae Gun Kim Jeong Won Kim Jin Woo Lee 《Organic Electronics》2012,13(5):820-825
Highly enhanced electron injection is demonstrated with a thin manganese dioxide (MnO2) electron injection layer (EIL) in Alq3-based organic light-emitting diodes. Insertion of the MnO2 EIL between the Al cathode and Alq3 results in highly improved device characteristics. In situ photoelectron spectroscopy shows remarkable reduction of the electron injection barrier without significant chemical reactions between Alq3 and MnO2, which could induce Alq3 destruction. The reduction of the electron injection barrier is due to the n-type doping effect, and the lack of strong interfacial reaction is advantageous with regards to more efficient electron injection than a conventional LiF EIL. These properties render the MnO2, a potential EIL. 相似文献
130.
Sunghun Lee Jeong-Hwan Lee Kwon Hyeon Kim Seung-Jun Yoo Tae Gun Kim Jeong Won Kim Jang-Joo Kim 《Organic Electronics》2012,13(11):2346-2351
A simple method based on capacitance–voltage (C–V) measurements is reported to determine the interface energy level alignment at the junction of 15 mol% Cs2CO3 doped 4,7-diphenyl-1,10-phenanthroline (BPhen) and 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HATCN) fabricated under high vacuum. The junction properties, such as the depletion layer thickness, built-in potentials and vacuum level shift were calculated with simple Mott–Schottky and Poisson’s equations with the boundary condition of a continuous electric flux density using the information from the C–V data. The interface energy level alignment determined by this method is well matched with the one determined using the in situ ultraviolet photoemission spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS) experiments performed under ultra-high vacuum. This method can be applied to other semiconductor junctions such as the organic p–n homojunctions and heterojunctions with known energy levels, as long as the metal/semiconductor contact is Ohmic without referring to the photoemission spectroscopies. Moreover, the energy level alignment determined by the C–V measurement gives a more realistic result since the films for the measurements are formed under high vacuum which is a normal device fabrication environment rather than under ultra high vacuum. 相似文献