Random data Cauchy theory for supercritical wave equations II : A global existence result

We prove that the subquartic wave equation on the three dimensional ball $\Theta$, with Dirichlet boundary conditions admits global strong solutions for a large set of random supercritical initial data in $\cap_{s<1/2} H^s(\Theta)$. We obtain this result as a consequence of a general random data Cauchy theory for supercritical wave equations developed in our previous work \cite{BT2} and invariant measure considerations which allow us to obtain also precise large time dynamical informations on our solutions

Surface texturing of steel by femtosecond laser and accompanying structure/ phase transformations

Topography, structure, and phase composition of surface layers of AISI 321 stainless steel textured by 1030-nm 320-fs-laser pulses were studied by scanning electron microscopy and X-ray diffraction analysis. Variation in single-pulse fluence and the number of pulses was found to change the laser-produced surface texture from onedimensional quasi-periodic nanograting to microrelief of various roughnes

XPS and DFT study of pulsed Bi-implantation of bulk and thin-films of ZnO - the role of oxygen imperfections

An atomic and electronic structure of the bulk and thin-film morphologies of ZnO were modified using pulsed Bi-ion implantation (1x1017 cm-2 fluence, 70 min exposure under Bi-ion beam, EBi+ = 30 keV, pulsed ion-current density of not more than 0.8 mA/cm2 with a repetition rate of 12.5 Hz). The final samples were qualified by X-ray photoelectron core-level and valence band mapping spectroscopy applying ASTM materials science standard. The spectroscopy data obtained was discussed on the basis of DFT-models for Bi-embedding into ZnO host-matrices. It was established that in the case of direct Bi-impurities insertion into the employed ZnO-host for both studied morphologies neither the only "pure" Bi2O3-like phase nor the only "pure" Bi-metal will be preferable to appear as a secondary phase. An unfavorability of the large cluster agglomeration of Bi-impurities in ZnO-hosts has been shown and an oxygen 2s electronic states pleomorphizm was surely established.Comment: 20 pages, 8 figures, 2 tables, accepted to Appl. Surf. Sc

Residual stresses in Ti6Al4V alloy after surface texturing by femtosecond laser pulses

Surface topography and residual stresses in surface layers of α + β titanium alloy Ti6Al4V textured by 1030-nm, 320-fs-laser pulses were studied by scanning electron microscopy and X-ray diffraction analysis. It was found that multipulse laser processing leads to the formation of laser-induced periodic surface structures (LIPSS) on the surface of Ti6Al4V alloy. XRD studies showed that depending on the laser pulse fluence, both tensile and compressive residual stresses are formed in thin near-surface layer

Static Analysis Technique for Searching Natural Semantic Defects of Program Objects and Software Implementation of This Approach Based on the LLVM Compiler Infrastructure and the Clang Frontend

В статье описывается методика статического анализа для поиска функциональных дефектов программ, разработка которой обусловлена необходимостью создания качественного отечественного программного обеспечения автоматизированных систем военного назначения в условиях временных и финансовых ограничений процесса разработки. Использование статического анализа позволит автоматизировать процесс выявления дефектов и упростит их локализацию в рамках мероприятий процесса верификации, при этом приоритетным объектом проверок должно быть специальное программное обеспечение вновь создаваемых автоматизированных систем ввиду своей эксклюзивности, масштабности и логической сложности. Предлагается подход, основанный на контроле выполнения принципа размерной однородности физических уравнений, представленных в программе, для чего идентификаторам программных объектов назначается неизменный признак в виде вектора физической размерности интерпретируемой величины. Совокупность всех векторов образует семантический домен, используемый при проверке соотношений между программными объектами по аналогии с анализом зависимостей при абстрактной интерпретации. Для проверки используется внутреннее представление программы, по которому происходят вычисления производных векторов на основании операций с исходными программными объектами. Программная реализация предлагаемой методики основывается на компиляторе LLVM и фронтенде Clang для трансляции кода на языках C, C++, Objective-C. Получаемое с помощью API Clang абстрактное синтаксическое дерево модифицируется для хранения данных о векторах программных объектовThe article proposes a static analysis technique for searching functional software defects. Development is caused by the need to create high quality domestic military automated system software in conditions of temporary and financial constraints. The use of static analysis makes it possible to automate the process of error detection and it allows to localizing defects simply. The priority object of inspections should be special software for newly created automated systems because it is exclusively, scale and logical complexity. An approach based on controlling the implementation of principle of dimensional homogeneity of the physical equations presented in the software. For this purpose, program objects identifiers are assigned an invariable attribute in the form of a physical dimension vector of interpreted value. The set of all vectors forms a semantic domain used in verifying the relationships between program objects by analogy with the analysis of dependencies in the abstract interpretation. The technique uses a program internal representation for calculations of derivate vectors on the basis of operations with initial program objects. The software implementations uses the LLVM compiler and Clang frontend to translate code in C, C++, Objective-C. Clang API internal representation in the form of abstract syntax tree is modified to store data about program objects vector

Formation of the oxide coating on the titanium surface by multipulse femtosecond laser irradiation

The effect of the femtosecond laser irradiation on the formation of oxide layers on the surface of a commercially pure titanium VT1-0 was studied. The methods of X-ray analysis, scanning electron and transmission electron microscopies were used to study the structural and phase state of oxide layers. As a result of the femtosecond laser irradiation, the porous multi-phase nanocrystalline oxide coating with a thickness of 50 µm is formed on the titanium surfac