Search

The coupling between ionic degrees of freedom and ferroelectricity has received renewed attention in recent years, given that surface electrochemical processes have been shown to be intrinsically linked to ferroelectric phase stability in ultrathin ferroelectric films. However, the coupling between bulk ionic transport and local polarization switching has received less attention, as typically the bulk ionic mobilities are low for common ferroelectrics at room temperature. Here, we use the coupled band-excitation method in conjunction with site-correlated time-of-flight secondary ion mass spectrometry, to determine the coupling between ferroelectric switching and ionic motion in single crystal KTiOPO4. The local scanning probe measurements indicate a substantial softening, as determined by resonant frequency changes, during reversal of polarization along one direction. These changes are correlated with the mass spectrometry measurements, showing a polarization-dependent accumulation of K ions at the polar surfaces, thus corroborating their role in the screening process. These studies shed light on the interplay between ionic dynamics and bulk ferroelectric switching and have implications for studies on domain wall conductivity, chemical switching, and bulk and surface-screening phenomena., Export Date: 22 October 2018; Article; Correspondence Address: Vasudevan, R.K.; Center for Nanophase Materials Sciences, Oak Ridge National LaboratoryUnited States; email: vasudevanrk@ornl.gov; Funding details: DOE, U.S. Department of Energy; Funding details: VR, Vetenskapsrådet; Funding details: SSF, Stiftelsen för Strategisk Forskning; Funding details: SC, Office of Science; Funding details: DE-AC05-00OR22725; Funding details: DMSE, Division of Materials Sciences and Engineering; Funding details: CNMS2017-066; Funding text: A portion of this work was sponsored by the U.S. Department of Energy (DOE), Office of Science, Materials Sciences and Engineering Division (R.K.V. and S.V.K.). Research was conducted at the Center for Nanophase Materials Sciences (A.I., S.J., O.S.O.), which is a DOE Office of Science User Facility, and using instrumentation within ORNL’s Materials Characterization Core provided by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. G.L. and C.C. acknowledge support and access to the Center for Nanophase Materials Sciences through the proposal CNMS2017-066. G.L. and C.C. also acknowledge support from the Swedish Foundation for Strategic Research and the Swedish Research Council (VR) through its Linné Center for Advanced Optics and Photonics (ADOPT). QC 20181112

Helium ion microscopy (HIM), enabled by a gas field ion source (GFIS), is an emerging imaging and nanofabrication technique compatible with many applications in materials science. The scanning electron microscope (SEM) has become ubiquitous in materials science for high-resolution imaging of materials. However, due to the fundamental limitation in focusing of electron beams, ion-beam microscopy is now being developed (e.g., at 20 kV the SEM beam diameter ranges from 0.5 to 1 nm, whereas the HIM offers 0.35 nm). The key technological advantage of the HIM is in its multipurpose design that excels in a variety of disciplines. The HIM offers higher resolution than the best available SEMs as well as the traditional gallium liquid-metal ion source (LMISs) focused ion beams (FIBs), and is capable of imaging untreated biological or other insulating samples with unprecedented resolution, depth of field, materials contrast, and image quality. GFIS FIBs also offer a direct path to defect engineering via ion implantation, three-dimensional direct write using gaseous and liquid precursors, and chemical-imaging options with secondary ion mass spectrometry. HIM covers a wide range of tasks that otherwise would require multiple tools or specialized sample preparation. In this article, we describe the underlying technology, present materials, relevant applications, and offer an outlook for the potential of FIB technology in processing materials.

The article shows that effective regional development is impossible without highly qualified personnel who leave the weak areas in search of application of the forces in the more advanced and developed regions. The recommendations for the establishment of regional support universities able to conduct training necessary for regional development., В статье показано, что эффективное региональное развитие невозможно без высококвалифицированных кадров, которые покидают слабые территории в поисках приложения своих сил в более перспективных и развитых регионах. Даются рекомендации по формированию региональных опорных вузов, способных вести подготовку кадров, необходимых для регионального развития.

It is traditionally considered that the scientific research work is carried out in higher education institutions only. But the development of types and ways of thinking happens much more earlier. That's why the research work should be an important part of school education. Every year students of schools of our town take part in a theoretical and practical conference where they are to present their research projects in different subjects. In this article we'll speak about the research projects in English and give a guide on what the research project is, Традиционно считается, что научно-исследовательская деятельность осуществляется в ВУЗе, но формирование типов и стилей мышления происходит значительно раньше, поэтому научно-исследовательская работа должна стать неотъемлемой частью школьного образования. Каждый год обучающиеся школ нашего города принимают участие в научно-практической конференции, на которой они должны представить научно-исследовательский проект по разным предметам. В статье мы рассматриваем, что представляет собой научно-исследовательский проект по предмету «Английский язык»

All-trans retinoic acid, controlled by cytochrome P450, family 26 (CYP26) enzymes, potentially has beneficial effects in atherosclerosis treatment. This study investigates CYP26 subfamily B, polypeptide 1 (CYP26B1) in atherosclerosis and the effects of a genetic polymorphism in CYP26B1 on retinoid catabolism. We found that CYP26B1 mRNA was induced by retinoic acid in human atherosclerotic arteries, and CYP26B1 and the macrophage marker CD68 were colocalized in human atherosclerotic lesions. In mice, Cyp26B1 mRNA was higher in atherosclerotic arteries than in normal arteries. Databases were queried for nonsynonymous CYP26B1 single nucleotide polymorphisms (SNPs) and rs2241057 selected for further studies. Constructs of the CYP26B1 variants were created and used for production of purified proteins and transfection of macrophagelike cells. The minor variant catabolized retinoic acid with significantly higher efficiency, indicating that rs2241057 is functional and suggesting reduced retinoid availability in tissues with the minor variant. rs2241057 was investigated in a Stockholm Coronary Atherosclerosis Risk Factor (SCARF) subgroup. The minor allele was associated with slightly larger lesions, as determined by angiography. In summary, this study identifies the first CYP26B1 polymorphism that alters CYP26B1 capacity to metabolize retinoic acid. CYP26B1 was expressed in macrophage-rich areas of human atherosclerotic lesions, induced by retinoic acid and increased in murine atherosclerosis. Taken together, the results indicate that CYP26B1 capacity is genetically regulated and suggest that local CYP26B1 activity may influence atherosclerosis.

Рассматривается сущность процесса развития профессиональной коммуникативной компетентности будущих учителей иностранного языка, который направлен на обеспечение студентов профессиональными коммуникативными знаниями, развитие ценностно-мотивационной сферы, формирование практических умений иноязычного межличностного и межкультурного профессионального общения. Выделяются компоненты исследуемого педагогического процесса: целевой, содержательный, организационно-деятельностный и оценочно-результативный и дается описание каждого компонента., The process of developing the communicative competence of foreign language teachers is considered. The aim of this process is to give students professional communicative knowledge, to develop their value and motivational sphere, to form practical skills of interpersonal and intercultural professional communication. Goal, content, activities-organizing and result evaluation components of the educational process under study are distinguished. Each component is described.