XANES/EPR Evidence of the Oxidation of Nickel(II) Quinolinylpropioamide and Its Application in Csp3−H Functionalization

An in situ generated oxidation species of nickel quinolinylpropioamide intermediate was produced. Characterization by X-ray absorption near edge structure (XANES) and EPR provides complementary insights into this oxidized nickel species. With aliphatic amides and isocyanides as substrates, a nickel-catalyzed facile synthesis of structurally diverse five-membered lactams could be achieved.     

Instabilities of soap film structures in square cuboid frame

ABSTRACT

Through the simulations performed with the Surface Evolver, we explored the T1s and the eight-fold vertex related topological changes in the square cuboid frame by changing the axial ratio λ and the liquid fraction ?. A stability diagram is provided to illustrate the instabilities encountered in any quasi-static process. Metastable film configurations are always accompanied by pre-emptive instabilities, while the instabilities of stable film configurations are not triggered until the central quadrilateral film steadily vanishes.     

Anti-resonant reflecting photonic crystal waveguide (ARRPCW): modeling and design

In this paper, we apply an antiresonant reflecting layer concept in photonic crystal based waveguides. We have proposed a thin core ARRPCW with linear waveguide carved in it and hence calculated the transmission spectra for various length of waveguide and have shown that the longer waveguides in ARRPCW yields transmission with significantly high quality factor. Comparison of the transmission characteristics of normal conventional planar ARROW-B waveguides & ARRPCW has also been reported. The 2D FDTD numerical modeling reveals improved transmission for various lengths of planar ARROW and ARRPCW with low losses in long waveguides. Transmittance and quality factor are also calculated to confirm superior performance of the proposed design of ARROW based photonic crystal waveguide.     

Effect of initial orientation on twinning in commercially pure titanium

Abstract

The effect of initial orientation on twinning micro-mechanisms during tensile deformation of commercially pure titanium has been studied using micro focus X-ray diffraction and electron back scatter diffraction (EBSD) in a scanning electron microscope. Three orientations A, B and C obtained from a rolled and annealed block of commercially pure titanium were deformed in uniaxial tension till failure and the tested specimens were characterised with regard to bulk texture, microstructure and crystal orientation mapping using EBSD. Orientation B along the transverse direction in ND-TD plane exhibits higher strength and lower strain hardening compared to orientations A and C along the rolling direction in TD-RD and ND-RD plane, respectively. This is attributed to different texture of sample B compared to samples A and C leading to dissimilar twinning micro-mechanisms and characteristic variation in nature of twinning. It is observed that limited twin nucleation and prominent lateral growth plays a dominant role in orientation B while multiple twin nucleation with significant non-Schmid behaviour is dominant for the other two orientations. It is proposed from this study that conventional factors associated with twin formation like Schmid factor play a main role in twin nucleation and propagation, however, growth or lateral thickening of the twins is explained by elastic stiffness variation across twins and their parent grains.     

Behavior of nonlinear fluid viscous dampers for control of shock vibrations

Fluid viscous dampers have been widely used for suppression of high velocity shocks. While linear fluid viscous dampers have been used for a long time, nonlinear fluid viscous dampers show considerable promise due to their superior energy dissipation characteristics and significant reduction in the damper force compared to a linear fluid viscous damper for the same peak displacement. This paper presents results from experimental study to characterize fluid viscous dampers when subjected to half-cycle sine shock excitation. The mathematical formulation and a numerical study to evaluate the relative performance of structures with fluid viscous dampers subjected to short-duration shock (impulse) loading are also discussed. The influence of damper nonlinearity (α) and the supplemental damping ratio (ξ_sd) on response has been investigated. The supplemental damping ratio of nonlinear fluid viscous dampers when subjected to shock excitation is found by equivalent linearization using the concept of equal energy dissipation. The paper also presents some design charts, which can be used for preliminary decisions on parameters of nonlinear dampers to be used in design.     

Ballistic transmission through quasi-periodic shape barrier resonant tunneling structures

A theoretical model is proposed to study the ballistic electron transport for a quasi-periodic multibarrier structure where two different barrier shapes are arranged according to the Thue–Morse sequence. Important tunneling features are revealed form such arrangements. It is noted that the tunneling band spectrum could be fragmented by tailoring the shape of the barriers in the structure. Results for the transmission coefficients and the current densities are compared with the corresponding periodic and single shape barrier arrangements. The quasi-periodic structure consisting of the rectangular and triangular barrier shapes is suggested to be more suitable for the electronic and opto-electronic devices due to its high negative differential conducting effect.     

On Markuševič decompositions of Banach spaces

пРОВЕДЕНО сИстЕМАтИ ЧЕскОЕ ИсслЕДОВАНИЕ РАжлИЧНых тИпОВ РАжлОжЕНИИ, А ИМ ЕННО, пО МАРкУшЕВИЧУ, ОБОБЩЕН Ных И РАжлОжЕНИИ пО шА УДЕРУ. УкАжАНы пРИМЕРы, ИллУ стРИРУУЩИЕ ВжАИМООтНОшЕНИь ЁтИ х тИпОВ РАжлОжЕНИИ. Ос НОВНАь цЕль ДАННОИ РАБОты — ИжУЧЕ НИЕ РАжлОжЕНИИ пО МАРкУшЕВИЧУ (M-РАжл ОжЕНИИ). ОтМЕЧАЕтсь, Чт О пОслЕДОВАтЕльНОсть пРОЕкцИИ, сВьжАННАь с ОБОБЩЕНН ыМ РАжлОжЕНИЕМ, ьВльЕ тсь ЕДИНстВЕННОИ тОгДА И тОлькО тОгДА, кОгДА ЁтОM-РАжлОжЕНИЕ. пОлУ ЧЕНА хАРАктЕРИжАцИьM-РАжлОжЕНИИ В тЕРМИН Ах Их пОДпОслЕДОВАтЕ льНОстЕИ. пОлУЧЕНА тАкжЕ хАРАк тЕРИжАцИь пО шАУДЕРУ В тЕРМИНАхM-РАжлОжЕНИИ. НАкОНЕц, пОлУЧЕНы ОтНОшЕНИь Д ВОИстВЕННОстИ МЕжДУM-РАжлОжЕНИьМИ НЕкОтО РОгО пРОстРАНстВА И НЕкОтОРыМИ РАжлОжЕ НИьМИ сОпРьжЕННОгО п РОстРАНстВА.     

Increased expression of epidermal fatty acid binding protein, cofilin, and 14-3-3-sigma (stratifin) detected by two-dimensional gel electrophoresis, mass spectrometry and microsequencing of drug-resistant human adenocarcinoma of the pancreas.

In order to study possible mechanisms leading to chemoresistance in pancreatic adenocarcinoma we examined the global protein expression of pancreatic cancer cells in vitro. We used a cell culture model derived from the adenocarcinoma of the pancreas (EPP85-181P). A classical multidrug-resistant subline, EPP85-181RDB, selected in presence of daunorubicin, and an atypical multidrug-resistant cell variant, EPP85-181RNOV, selected in presence of mitoxantrone, were analyzed using two-dimensional electrophoresis. After staining and image analysis, spots of interest were isolated using preparative two-dimensional electrophoresis and subjected to mass spectrometry and microsequencing. Three proteins, E-FABP, cofilin, and 14-3-3-sigma (stratifin), were overexpressed in chemoresistant cell lines. Cofilin was present in both multidrug in chemoresistant cell lines. Cofilin was present in both multidrug-resistant cell lines. E-FABP and 14-3-3-sigma (stratifin) was found to be overexpressed only in the mitoxantrone-selected atypical multidrug-resistant cell line. The possible significance of these findings is discussed.