Migration of indium ions in amorphous indium-gallium-zinc-oxide thin film transistors

Electromigration of In in amorphous indium-gallium-zinc-oxide thin film transistors under repeated switching operation was investigated by analyzing the distribution of component elements. During the repeated switching operations up to 300 times, threshold voltage of this device increased gradually implying alteration to the internal device structures. Energy dispersive X-ray spectroscopy revealed noticeable redistribution of metallic components, especially In, in the channel layer beneath the source electrode during switching operations by the migration of metallic ions away from the source electrode, which is attributed to electromigrations similar to those observed in organic light emitting diodes having indium tin oxide electrodes.     

Molecular Recognition in Glycolaldehyde,the Simplest Sugar: Two Isolated Hydrogen Bonds Win Over One Cooperative Pair

Carbohydrates are used in nature as molecular recognition tools. Understanding their conformational behavior upon aggregation helps in rationalizing the way in which cells and bacteria use sugars to communicate. Here, the simplest α-hydroxy carbonyl compound, glycolaldehyde, was used as a model system. It was shown to form compact polar C₂-symmetric dimers with intermolecular O–H⋅⋅⋅O=C bonds, while sacrificing the corresponding intramolecular hydrogen bonds. Supersonic jet infrared (IR) and Raman spectra combined with high-level quantum chemical calculations provide a consistent picture for the preference over more typical hydrogen bond insertion and addition patterns. Experimental evidence for at least one metastable dimer is presented. A rotational spectroscopy investigation of these dimers is encouraged, also in view of astrophysical searches. The binding motif competition of aldehydic sugars might play a role in chirality recognition phenomena of more complex derivatives in the gas phase.     

Synthesis and proton conductivity of sulfonated,multi‐phenylated poly(arylene ether)s

A series of sterically‐encumbered, sulfonated, poly(arylene ether) copolymers were synthesized and their proton conductivity examined. The series was prepared by copolymerizing a novel monomer, 2″,3″,5″,6″‐tetraphenyl‐[1,1′:4',1″:4″,1″':4″',1″″‐quinquephenyl]‐4,4″″‐diol, with 4,4'‐difluorobenzophenone and bisphenol A. Subsequent sulfonation and solution casting provided membranes possessing ion exchange capacities of 1.9 to 2.7 mmol/g and excellent mechanical properties (Young's modulus, 0.2–1.2 GPa; tensile strength, 35–70 MPa; elongation at break, 62–231%). Water uptake ranged from 34 to 98 wt% at 80 °C/100% RH. Proton conductivities ranged between 0.24 to 16 mS/cm at 80 °C/60% RH, and 3 to 167 mS/cm at 80 °C/95% RH. TEM analysis of the polymers, in the dehydrated state, revealed isolated spherical aggregates of ions, which presumably coalesce when hydrated to provide highly conductive pathways. The strategy of using highly‐encumbered polymer frameworks for the design of mechanically‐robust and dimensionally‐stable proton conducting membranes is demonstrated. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2579‐2587     

Effect of irradiation on the cryogenic mechanical characteristics of polyurethane foam

The present study investigated thermal and mechanical characteristics of irradiated polyurethane foams (PUFs) according to the irradiation does under various temperature conditions, including low/cryogenic temperatures. Fourier transform infrared analysis was performed to obtain information on the PUF molecular structure. In addition, Macro- and microstructural investigations were carried out to determine the relationship between thermal and mechanical characteristics and irradiation dose. The test results were quantitatively presented, and it was found that the irradiated PUF has potential for application in industrial structures.     

An extended chaotic-maps-based protocol with key agreement for multiserver environments

Due to the rapid development and growth of computer networks, there have been greater and greater demands for remote password authentication protocols. Recently, the focus has been on protocols for multiserver environments that run on smart cards. These protocols typically count on the nonce or timestamp to provide protection against the replay attack. However, as Tsaur et al. pointed out, these protocols have some security issues such as disturbance in clock synchronization and vulnerability to the man-in-the-middle attack. In order to solve the above problems, Tsaur et al. proposed a multiserver authentication scheme with key agreement in 2012, and they claimed that their scheme could effectively achieve password-authenticated key agreement while getting around the technical difficulty of implementing clock synchronization in multiserver environments. Unfortunately, we found out that Tsaur et al.’s protocol still has the following weaknesses: (1) inability to resist privileged insider attack, (2) inability to resist known-plaintext attack, (3) inability to provide user anonymity, and (4) lack of perfect forward secrecy. To fix these secure flaws of Tsaur et al.’s protocol, in this paper, we shall propose an improved multiserver authentication protocol with key agreement based on extended chaotic maps. We shall also offer formal proof of smooth execution of the improved authenticated key agreement protocol.     

Ferromagnetic to Paramagnetic Transition in Spherical Spin Glass

Journal of Statistical Physics - We consider the spherical spin glass model defined by a combination of the pure 2-spin spherical Sherrington–Kirkpatrick Hamiltonian and the ferromagnetic...     

High dielectric constant nickel-doped titanium oxide films prepared by liquid-phase deposition

The electrical characteristics of nickel-doped titanium oxide films prepared by liquid-phase deposition on p-type (100) silicon substrate were investigated. The aqueous solutions of ammonium hexafluorotitanate and boric acid were used as precursors for the growth of titanium oxide films and the dielectric constant is 29. The dielectric constant can be improved to 94 by nickel doping at the thermal annealing at 700 °C in nitrous oxide.