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451.
Reliable and precise knowledge about the strain and composition effects on the electronic properties is crucial for the optimization of III-nitride based heterostructures for electronic and optoelectronic device applications. Using the nearest neighbor semi-empirical tight binding formalism, we investigated the composition effects on bandgaps and offsets in pseudomorphic InGaN/GaN and GaAsN/GaAs heterostructures with zinc-blende structures. The strain effects are incorporated afterwards in a semi-empirical way. The model should be useful in understanding the effects of composition and strain on heterostructure energy band properties. 相似文献
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454.
In this paper, we examine the pseudo-spherical curves, which are equivalent to each other under the conformal maps preserving a fixed point in the de Sitter 2-space, by using the Clifford algebra Cl 2,1. Also, we find the parametric equations of de Sitter loxodromes. 相似文献
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456.
Poly(p‐phenylene) with Poly(ethylene glycol) Chains and Amino Groups as a Functional Platform for Controlled Drug Release and Radiotherapy 下载免费PDF全文
Bahar Guler Huseyin Akbulut Firat Baris Barlas Caner Geyik Dilek Odaci Demirkol Ahmet Murat Senisik Halil Armagan Arican Hakan Coskunol Suna Timur Yusuf Yagci 《Macromolecular bioscience》2016,16(5):730-737
Conventional cancer treatments such as chemotherapy, radiotherapy, or combination of these two result in side effects, which lower the quality of life of the patients. To overcome problems with these methods, altering the drug properties by conjugating them to carrier polymers has emerged. Such polymeric carriers also hold the potential to make tumor cells more sensitive to radiation therapy. Herein, poly(p‐phenylene) (PPP) polymer with poly(ethylene glycol) (PEG) chains and primary amino groups (PPP‐NH2‐g‐PEG) is synthesized and conjugated with anticancer drug Doxorubicin (DOX). pH dependent drug release experiments are performed at pH 5.3 and pH 7.4, respectively. Cell viability studies on human cervix adenocarcinoma cells show that lower doses of DOX inhibit cell proliferation when conjugated with nontoxic doses of PPP‐NH2‐g‐PEG polymer. Additionally, PPP‐NH2‐g‐PEG/Cys/DOX bioconjugate significantly increases radiosensitive properties of DOX. It is possible to use lower doses of DOX when conjugated to PPP‐NH2‐g‐PEG in combination with radiotherapy.
457.
The role of spontaneous waves in the deflagration-to-detonation transition in submillimetre channels
Flame acceleration and transition to detonation in submillimetre two-dimensional planar and three-dimensional square channels were simulated by solving the compressible reactive Navier–Stokes equations. A simplified chemical–diffusive model was used to describe the diffusive transport and chemical reaction of a highly reactive mixture, such as stoichiometric ethylene and oxygen in 2D and 3D channels. The walls of the channels were modelled as no-slip and adiabatic. The initial flame acceleration and precursor shock formation were consistent with earlier results. Viscous dissipation in the boundary layer heats the reactants, which have been compressed by the precursor shock. The strength of the precursor shock and the amount of viscous dissipation increase until the temperature of the boundary layer is high enough to ignite the reactants. This produces a spontaneous wave, which, in most of the cases considered, initiates the detonation. The spontaneous wave first forms where the flame attaches to the wall in the planar channels, and forms at the corner where two walls meet in the square channels. In a separate study, the boundary layer also ignited in a computation for a circular tube containing a mixture hydrogen and oxygen represented by a detailed chemical reaction mechanism. The formation of spontaneous waves to the extent studied appears to be robust, and is relatively insensitive to channel geometry, fuel and oxidiser mixture, and the level of detail in the chemical–diffusive models used. 相似文献
458.
Nafion® impregnated Solupor®, microporous UHMWPE film, (N-PE), Nafion®117 (N117) and a membrane prepared using a DE2020 Nafion® dispersion (DE2020) were characterized with respect to their swelling degree (SD), methanol cross-over, proton conductivity and DMFC performance at various methanol concentrations in order to understand the effect of impregnation of an ion-conductive polymer membrane to the fuel cell performance. 相似文献
459.
Arslan H Demircan A Göktürk E 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,69(1):105-112
The IR spectra of 5-chloro-10-oxa-3-thia-tricyclo[5.2.1.0(1,5)]dec-8-ene-3,3-dioxide (COTDO) has been recorded in the region 4000-525cm(-1). The optimized molecular geometry, frequency and intensity of the vibrational bands of COTDO in the ground state has been calculated using the Hartree-Fock and density functional using Becke's three-parameter hybrid method with the Lee, Yang, and Parr correlation functional methods with 6-31G(d,p) and 6-311G(d,p) basis sets. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental IR spectra. The calculated geometrical parameters and harmonic vibrations are predicted in a very good agreement with the experimental data. The theoretical vibrational spectra of the title compound were interpreted by means of potential energy distributions (PEDs) using VEDA 4 program. With the help of this modern technique we were able to complete the assignment of the vibrational spectra of the title compound. 相似文献
460.
New electron-deficient and soluble indenofluorene-based and bisindenofluorene-based ladder-type building blocks embedding carbonyl and dicyanovinylene functionalities were synthesized, and their optical and electrochemical properties were characterized. These derivatives exhibit optical band gaps of 1.83 to 2.44 eV and low LUMO energies of -3.24 to -4.30 eV, representing a promising new building block class for n-type polymeric electronic materials. 相似文献