Search Results - (Author, Cooperation:M. A. Herman)

2012-04-03

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Adipocytes/metabolism ; Adipose Tissue/cytology/*metabolism/pathology ; Adiposity ; Animals ; Basic Helix-Loop-Helix Leucine Zipper Transcription ; Factors/chemistry/genetics/*metabolism ; Blood Glucose/metabolism ; Body Mass Index ; Body Weight ; Cells, Cultured ; Cohort Studies ; Cross-Sectional Studies ; Diabetes Mellitus/blood/genetics/metabolism ; Female ; Gene Expression Regulation/genetics ; Genotype ; Glucose/*metabolism/pharmacology ; Glucose Intolerance/genetics ; Glucose Transporter Type 4/biosynthesis/genetics/metabolism ; Homeostasis/genetics ; Humans ; Insulin/metabolism/pharmacology ; Insulin Resistance/genetics ; Lipogenesis ; Male ; Mice ; Mice, Knockout ; Molecular Sequence Data ; Nuclear Proteins/chemistry/deficiency/genetics/*metabolism ; Obesity/genetics/metabolism ; Promoter Regions, Genetic/genetics ; Protein Isoforms/chemistry/genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Transcription Factors/chemistry/deficiency/genetics/*metabolism

1089-7550

AIP Digital Archive

Physics

This paper presents a review devoted to the problem of how optical and structural properties of quantum-well heterostructures (QWH) can be correlated in detail, and how these properties may be connected with the parameters of the epitaxial growth process. It demonstrates how luminescence techniques, mainly photoluminescence (PL) and cathodoluminescence imaging (CLI), may be used for evaluation of the structural disorder on the atomic scale, which occurs at the growth surfaces creating the interfaces of the QWH. The physics of the excitonic luminescence in QWH (theory and experiment) is presented in detail in the first part of the review. This is followed by a comprehensive discussion of experimental aspects (hardware and software) of the luminescence techniques, as applied for studying QWH grown by molecular-beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE). The specific features of both the epitaxial growth techniques, when used for growing QWH are presented in the next part of this review. Finally, the possibilities of application of PL and CLI to studies on growth of QWH by MBE and MOVPE are demonstrated on a couple of selected examples. The review concludes with a short discussion on possible interpretation mistakes which may occur when one applies the CLI to studies of interfaces in QWH without taking into account the basic parameters of the excitonic luminescence lines creating the CL images of the relevant interfaces.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Thermal desorption experiments concerning Te deposits on GaAs (100) surfaces have been performed using quadrupole mass spectrometry. The results give evidence that near the GaAs surface two regions of different Te adsorption can be distinguished. The first region nearest to the substrate surface consists of Te adparticles, which are chemisorbed to the substrate reevaporating at temperatures above 510–520 °C. The adparticles of the second physisorbed region begin to desorb at 350–360 °C, which is still considerably higher than the desorption temperature of the bulk Te deposits. The approximate thicknesses of these two regions are 1–2 monolayers and 3–10 monolayers of Te, respectively.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

The experimental procedure and the results of in situ determination of growth temperatures, refractive indices at growth temperatures, and thicknesses of ZnTe, cubic MnTe, and CdTe thin films grown by molecular beam epitaxy (MBE) are reported. Visible laser interferometry with He-Ne laser 0.6328-μm light has been applied in the performed experiments. A 290-μm-thick plane-parallel GaP wafer polished to an optical finish on both sides has been used as a growth temperature calibration standard. The exemplary substrate temperature calibration curves, as well as the data gained at dynamic thermal conditions are presented and discussed. The following numerical values concerning refractive indices n at elevated temperatures have been evaluated from experimental data for the MBE grown films: n (286 °C)ZnTe=2.51, n (175 °C)ZnTe=2.49, n(286 °C)cubic MnTe=3.26, and the extinction coefficient k (286 °C)CdTe=0.23.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

This article presents a review of the state of the art of research and development on Hg1−xCdxTe -Hg1−yCdyTe (0≤x,y≤1) heterostructures important for applications in the modern infrared detection technique. It deals with the fundamental physical properties, epitaxial growth methods, and applications of these structures. The most important experimental results relevant to this subject are described and discussed. Following a short survey of the physical properties of Hg1−xCdxTe, the travelling heater method for growing bulk crystals of Hg1−xCdxTe has been described and compared with the epitaxial growth techniques used to prepare thin films and layered structures of this compound. Some important aspects of substrate preparation procedures related to CdTe wafers have been discussed. Then the most important problems regarding the liquid-phase, vapor-phase, and molecular-beam-epitaxy methods of Hg1−xCdxTe -Hg1−yCdyTe (0≤x,y≤1) heterostructures have been studied. A comprehensive discussion of technology and the parameters of different heterostructure photodiodes made of Hg1−xCdxTe with electrically passive and electrically active heterointerfaces has been presented. The review is concluded with an overview of research problems relevant to HgTe-CdTe superlattices and the surfaces and heterointerfaces of Hg1−xCdxTe.

Electronic Resource

1750-3841

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Process Engineering, Biotechnology, Nutrition Technology

The use of resonance Raman spectroscopy in the determination of food dyes was studied with the yellow, orange and red dyes registrated by the European Economical Community. The natural dyes studied did not exhibit a resonance Raman spectrum, but most of the artificial dyes give spectra that can be used for analytical determinations. The detection and identification limits are sufficiently low for practical use. The identification capability and its advantage over absorption spectrometric measurements are demonstrated on a commercial bubble gum sample. Quantitative measurements indicated a good accuracy for this method.

Electronic Resource

0140-1971

Psychology

1432-0630

68.55 ; 81.10 ; 85.60

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Abstract A simple selection rule for epitaxial growth techniques, which is based on morphological stability of the substrate surface is proposed. According to this rule a certain growth technique should be used for preparing a specific device structure of a three-dimensional monolithically integrated optical or electronic circuit. The formulae for morphological stability functions for LPE, MO, VPE, and MBE growth techniques are given. Calculations performed for the GaAs/Al x Ga1−x As material system by using the linear morphological stability theory of Mullins and Sekerka suggest that from the point of view of morphological stability the most suitable growth technique for fabrication of three-dimensional monolithically integrated optical and electronic device structures is the MBE technique.

Electronic Resource