Substrate bias effects on subband separation and interband scattering in Si (110) p-channel mosfets

Light and heavy hole subband splitting as a function of substrate bias is characterized and found to increase with increasing depletion charge. Oscillatory interband scattering is reported.     

Efficient cu-catalyzed asymmetric conjugate additions of alkylzincs to trisubstituted cyclic enones

The first examples of efficient catalytic asymmetric conjugate addition (ACA) of alkylzincs to trisubstituted cyclic enones is disclosed. These Cu-catalyzed reactions proceed efficiently with five- and seven-membered ring substrates to afford the desired products in >/=95% ee. Intermediate enolates can be trapped with alkyl halides to generate a quaternary stereogenic center. The requisite chiral ligand is prepared from commercially available materials and can be used in situ without further purification in the presence of commercial grade (CuOTf)2.PhMe.     

Internuclear distance determination of S = 1, I = 1/2 spin pairs using REAPDOR NMR

A universal function is proposed to describe REAPDOR dephasing curves of an observed spin-1/2 nucleus dipole-recoupled to a spin-1 quadrupolar nucleus ((2)H or (14)N). Previous work had shown that, in contrast to REDOR, the shape of the dephasing curve depends on a large number of parameters including the quadrupolar coupling constant and asymmetry parameter, the sample rotation speed, the RF amplitude, and the relative orientations of the quadrupole tensor and the internuclear vector. Here we demonstrate by numerical simulations that the actual dispersion of REAPDOR dephasing curves is quite small, provided the rotation speed and the RF amplitude applied to the quadrupolar nucleus satisfy an adiabaticity condition. The condition is easily met for (2)H and is also practically achievable for virtually any (14)N-containing compound. This allows the REAPDOR curves to be approximated by a simple universal gaussian-type function, comparison of which with experimental data yields internuclear distances with less than 4% error. The spin dynamics of the recoupling mechanism is discussed. The critical importance of a stable spinning speed for optimizing the signal-to-noise ratio of the (13)C echoes is demonstrated and practical suggestions for achieving high stability are presented. Examples of applications of the universal curve are given for (2)H/(13)C and (14)N/(13)C REAPDOR in alanine.     

Faster algorithms for string matching with k mismatches

The string matching with mismatches problem is that of finding the number of mismatches between a pattern P of length m and every length m substring of the text T. Currently, the fastest algorithms for this problem are the following. The Galil–Giancarlo algorithm finds all locations where the pattern has at most k errors (where k is part of the input) in time O(nk). The Abrahamson algorithm finds the number of mismatches at every location in time . We present an algorithm that is faster than both. Our algorithm finds all locations where the pattern has at most k errors in time . We also show an algorithm that solves the above problem in time O((n+(nk³)/m)logk).     

Venous cavernoma at 8 Tesla MRI

Cavernous angiomas or cavernomas are vascular malformations, which may be associated with risk of bleeding episodes. We present a case report comparing high resolution 8 Tesla gradient echo (GE) imaging with routine fast spin echo (FSE) at 1.5 Tesla in a patient with venous cavernoma. A 55-year-old male with a history of hemorrhagic stroke was studied using high-resolution 8 Tesla magnetic resonance imaging (MRI) system, which revealed venous cavernoma (9 x 8.6 mm) in the left parietal region and visualized adjacent microvascular supply. Signal loss was prominent in the cavernoma region compared to surrounding brain tissue, and signal intensity declined by factor 7.3 +/- 2.4 (679 +/- 62%) on GE images at 8 Tesla. Cavernoma was not apparent on routine T(2)-weighted FSE images at 1.5 Tesla MRI. This case report indicates that GE images at 8 Tesla can be useful for evaluation of vascular pathologies and microvasculature.     

Limiting Dynamics for Spherical Models of Spin Glasses at High Temperature

We analyze the coupled non-linear integro-differential equations whose solution is the thermodynamical limit of the empirical correlation and response functions in the Langevin dynamics for spherical p−spin disordered mean-field models. We provide a mathematically rigorous derivation of their FDT solution (for the high temperature regime) and of certain key properties of this solution, which are in agreement with earlier derivations based on physical grounds. AMS (2000) Subject Classification: Primary: 82C44, Secondery: 82C31, 60H10, 60F15, 60K35     

Alkylidene and metalacyclic complexes of tungsten that contain a chiral biphenoxide ligand. synthesis,asymmetric ring-closing metathesis,and mechanistic investigations

Two complexes that contain the racemic or enantiomerically pure (S) form of the 3,3'-di-tert-butyl-5,5',6,6'-tetramethyl-1,1'-biphenyl-2,2'-diolate (Biphen(2-)) ligand, W(NAr)(CHCMe(2)Ph)(Biphen) (2a) and W(NAr')(CHCMe(2)Ph)(Biphen) (2b) (Ar = 2,6-i-Pr(2)C(6)H(3); Ar' = 2,6-Me(2)C(6)H(3)), were prepared and shown to be viable catalysts for several representative ring-closing reactions to give products in good yields in most cases and high % ee in asymmetric reactions. Exploration of the reaction between 2a and a stoichiometric amount of one desymmetrization substrate allowed two intermediate tungstacyclobutane complexes to be observed, in addition to the final and quite stable tungstacyclobutane complex formed in a reaction between the ring-closed product and a tungsten methylene complex. Reactions involving (13)C labeled ethylene allowed for the observation of an unsubstituted tungstacyclobutane complex, an ethylene complex, an unsubstituted tungstacyclopentane complex, and a heterochiral dimeric form of a methylene complex. The tungstacyclopentane complex was found to catalyze the dimerization of ethylene to 1-butene slowly.     

Sentiment Analysis of Persian Movie Reviews Using Deep Learning

Sentiment analysis aims to automatically classify the subject’s sentiment (e.g., positive, negative, or neutral) towards a particular aspect such as a topic, product, movie, news, etc. Deep learning has recently emerged as a powerful machine learning technique to tackle the growing demand for accurate sentiment analysis. However, the majority of research efforts are devoted to English-language only, while information of great importance is also available in other languages. This paper presents a novel, context-aware, deep-learning-driven, Persian sentiment analysis approach. Specifically, the proposed deep-learning-driven automated feature-engineering approach classifies Persian movie reviews as having positive or negative sentiments. Two deep learning algorithms, convolutional neural networks (CNN) and long-short-term memory (LSTM), are applied and compared with our previously proposed manual-feature-engineering-driven, SVM-based approach. Simulation results demonstrate that LSTM obtained a better performance as compared to multilayer perceptron (MLP), autoencoder, support vector machine (SVM), logistic regression and CNN algorithms.     

Spectral Analysis of Large Scale Structures in Fully Developed Turbulent Pipe Flow

The present work focuses on spectral analysis of the streamwise velocity fluctuations obtained, utilizing the Cottbus Large Pipe (CoLaPipe) test facility for R⁺ ≤ 3500, where R⁺ is the Reynolds number based on the wall friction velocity, u_τ, and the pipe radius, R. Measurements of the streamwise spectra have been conducted using a single hot-wire probe. Few runs have been also performed using Particle Image Velocimetry (PIV) as a structure visualization evidence and for spatial correlation purposes. The spectral analysis is being carried out to reveal few insights into pipe flow structure, allowing to follow the foot prints of such structures as well as providing estimates of their energy contents. The cumulative energy is examined as a function of the streamwise wavelength, describing the most energetic motions found in spectral data at various wall normal locations. For the current Reynolds number range, the Very Large Scale Motions (VLSM) and the Large Scale Motions (LSM) were evident as localized peaks in pre-multiplied spectra, having mean wavelengths approximately of 12R, and 3R, respectively. (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Erratum to: Chemical and electrochemical grafting of polythiophene onto poly(vinyl chloride): synthesis,characterization, and materials properties

Journal of Solid State Electrochemistry -