FRACTAL-LIKE SQUARE LATTICES OF AIR HOLES H. T. Hattori
... conventiona geometric objects [15]. These special geometrical forms have a so been applied to optica devices [16–19], eading to DFB asers with improved performance [18, 19]. Also, fractals have been applied to antennas to produce specially tailored radiation beams [20]. In this article, we combine f ...
... conventiona geometric objects [15]. These special geometrical forms have a so been applied to optica devices [16–19], eading to DFB asers with improved performance [18, 19]. Also, fractals have been applied to antennas to produce specially tailored radiation beams [20]. In this article, we combine f ...
A1981KY95600002
... and high contents of imino acids. Since 1955, this protein was known to have a rope-like triplehelix structure,1 but three distinct models of this type differing substantially in conformation had been proposed. Because of collagen’s complex intermolecular packing and amino acid sequence a clear choi ...
... and high contents of imino acids. Since 1955, this protein was known to have a rope-like triplehelix structure,1 but three distinct models of this type differing substantially in conformation had been proposed. Because of collagen’s complex intermolecular packing and amino acid sequence a clear choi ...
T-Shaped Molecular Building Units in the Porous Structure of Ag(4,4
... molecular building units has yielded a remarkable class of materials having diverse architecture and functions.1 These include metal-organic solids with open frameworks having zeolite-like attributes2 and others having important electronic3 and magnetic4 properties. One of the simplest strategies em ...
... molecular building units has yielded a remarkable class of materials having diverse architecture and functions.1 These include metal-organic solids with open frameworks having zeolite-like attributes2 and others having important electronic3 and magnetic4 properties. One of the simplest strategies em ...
Second Harmonic Generation in Photonic Crystals UNIVERSITAT POLITECNICA DE CATALUNYA
... the fundamental and SH beams necessary for a continuous growth of the SH intensity is provided by the bending of the dispersion curve at the boundary of the forbidden zone or Bragg reflection band. Since each crystal has a different lattice constant, it is expected that the resulting SH beam appears ...
... the fundamental and SH beams necessary for a continuous growth of the SH intensity is provided by the bending of the dispersion curve at the boundary of the forbidden zone or Bragg reflection band. Since each crystal has a different lattice constant, it is expected that the resulting SH beam appears ...
Crystallization dynamics and interface stability of strontium titanate
... constant 2 detector angle of 15 with a Dectris Mythen onedimensional photodiode array and an exposure time of 150 s, while the sample surface was inclined by an angle ! of 2.5 with respect to the incident beam. Sample heating was facilitated by an Anton Paar DHS 1100 oven with a carbon dome under ...
... constant 2 detector angle of 15 with a Dectris Mythen onedimensional photodiode array and an exposure time of 150 s, while the sample surface was inclined by an angle ! of 2.5 with respect to the incident beam. Sample heating was facilitated by an Anton Paar DHS 1100 oven with a carbon dome under ...
INERT GASES -
... is particularly interesting because it is an experimental example of a quantum mechanical harmonic oscillator in a small box. The inert gases are also of interest to the chemical biologist. For example, xenon is found to be an almost perfect anesthetic agent-in spite of its chemical inertness. This ...
... is particularly interesting because it is an experimental example of a quantum mechanical harmonic oscillator in a small box. The inert gases are also of interest to the chemical biologist. For example, xenon is found to be an almost perfect anesthetic agent-in spite of its chemical inertness. This ...
A method for determining the magnitude of the Raman scattering
... It should be pointed out that field induced infrared absorption bands associated with Raman active modes of vibration; should also occur for other crystal structures having a center of symmetry, and for impurity modes. In the case of polar crystals such as CaF2 which exhibit a first order Raman acti ...
... It should be pointed out that field induced infrared absorption bands associated with Raman active modes of vibration; should also occur for other crystal structures having a center of symmetry, and for impurity modes. In the case of polar crystals such as CaF2 which exhibit a first order Raman acti ...
Using APL format - Massachusetts Institute of Technology
... disorder, and allows the widest bandwidth for optical devices. Most structures with complete PBGs are described by a diamond structure4 or fcc lattice, or a distorted cousin such as an A7 or graphite structure,5 due to their ‘‘near-spherical’’ Brillouin zones. Although this determines the underlying ...
... disorder, and allows the widest bandwidth for optical devices. Most structures with complete PBGs are described by a diamond structure4 or fcc lattice, or a distorted cousin such as an A7 or graphite structure,5 due to their ‘‘near-spherical’’ Brillouin zones. Although this determines the underlying ...
Direct methods and protein crystallography at low
... Three sorts of quartet can be identi®ed as follows. (i) Positive quartets, in which the principal and cross-terms are large. These are strongly correlated with triplets which makes them dif®cult to use. (ii) Negative quartets, where the principal terms are large and the cross-terms are small. (iii) ...
... Three sorts of quartet can be identi®ed as follows. (i) Positive quartets, in which the principal and cross-terms are large. These are strongly correlated with triplets which makes them dif®cult to use. (ii) Negative quartets, where the principal terms are large and the cross-terms are small. (iii) ...
Dislocations
... FCC and HCP, the HCP structure is the most likely to twin. ● FCC structures will not usually twin because slip is more energetically favorable. ● Twinning occurs at low temperatures and high rates of shear loading (shock loading) conditions where there are few present slip systems (restricting the p ...
... FCC and HCP, the HCP structure is the most likely to twin. ● FCC structures will not usually twin because slip is more energetically favorable. ● Twinning occurs at low temperatures and high rates of shear loading (shock loading) conditions where there are few present slip systems (restricting the p ...
Crystal habit and tableting behavior
... measurements at different maximal punch forces. Therefore, this method is not suitable for substances that are only available in very small amounts. Many other equations (Table 1) have been proposed to support a relation between porosity and applied pressure. To compare different crystal habits of i ...
... measurements at different maximal punch forces. Therefore, this method is not suitable for substances that are only available in very small amounts. Many other equations (Table 1) have been proposed to support a relation between porosity and applied pressure. To compare different crystal habits of i ...
Basic Principles of Protein Crystallography
... Epitaxial nucleation • Epitaxial nucleation is where the regularity of the surface facilitates nucleation. • Glass although siliconised can act as an adhesion surface • The strength of interaction with the glass can be stronger that the forces that bond the crystalline lattice • Crystals or micro-c ...
... Epitaxial nucleation • Epitaxial nucleation is where the regularity of the surface facilitates nucleation. • Glass although siliconised can act as an adhesion surface • The strength of interaction with the glass can be stronger that the forces that bond the crystalline lattice • Crystals or micro-c ...
STUDY ON CRYSTALLINITY AND COMPACTIBILITY OF BINARY MIXTURE OF ANALGESIC
... undergo rearrangement then having deformation or fracture. This deformation influenced by the arrangement of molecules within the crystal lattice, intermolecular interactions which provides rigidity in the crystal lattice, and the crystal defects or damage and the crystal orientation due to compress ...
... undergo rearrangement then having deformation or fracture. This deformation influenced by the arrangement of molecules within the crystal lattice, intermolecular interactions which provides rigidity in the crystal lattice, and the crystal defects or damage and the crystal orientation due to compress ...
Characterization of the pH-Mediated Solubility of Bacillus
... Cilmmol). Using a universal buffer formulated with the same ionic strength at every pH, we determined that native crystals dissolve above pH 10 and below pH 4. At the acidic pH, the rate of solubilization was substantially slower than at the alkaline pH. Recrystallization rates for the toxin were si ...
... Cilmmol). Using a universal buffer formulated with the same ionic strength at every pH, we determined that native crystals dissolve above pH 10 and below pH 4. At the acidic pH, the rate of solubilization was substantially slower than at the alkaline pH. Recrystallization rates for the toxin were si ...
Ferroelectrics
... • In addition to the change in spontaneous polarisation, temperature affects the dielectric constant of the material, normally defined as the rate of change of dielectric displacement with electric field. • For ferroelectrics where there is a nonlinear relationship between D and P, we ...
... • In addition to the change in spontaneous polarisation, temperature affects the dielectric constant of the material, normally defined as the rate of change of dielectric displacement with electric field. • For ferroelectrics where there is a nonlinear relationship between D and P, we ...
Chapter 9
... • Definition: the form taken by a mineral as a result of its internal arrangement of atoms • Flat surfaces on crystals are called “crystal faces.” • Most crystals don’t show crystal faces because they don’t have enough room to form. ...
... • Definition: the form taken by a mineral as a result of its internal arrangement of atoms • Flat surfaces on crystals are called “crystal faces.” • Most crystals don’t show crystal faces because they don’t have enough room to form. ...
Lattice parameter determination using a curved position
... is usually not guaranteed for every diffraction pattern obtained. This can be attributed to the variations in sample size, the exact mechanical positioning of specimen holders or the instability of the radiation source. Such errors in sample displacement may lead to errors in peak positions and cons ...
... is usually not guaranteed for every diffraction pattern obtained. This can be attributed to the variations in sample size, the exact mechanical positioning of specimen holders or the instability of the radiation source. Such errors in sample displacement may lead to errors in peak positions and cons ...
Unit 5 - PLANET EARTH TOPIC 1 – MINERALS
... 1. Please write the VOCABULARY words for the following definitions. P. ...
... 1. Please write the VOCABULARY words for the following definitions. P. ...
A third blind test of crystal structure prediction
... independent referee (Professor A. L. Spek, Laboratory of Crystal and Structural Chemistry, Utrecht University) who checked that they conformed to our criteria. After considerable effort, we collected six candidates for category 1, two for category 2 and six for category 3. (Here, we make a plea to t ...
... independent referee (Professor A. L. Spek, Laboratory of Crystal and Structural Chemistry, Utrecht University) who checked that they conformed to our criteria. After considerable effort, we collected six candidates for category 1, two for category 2 and six for category 3. (Here, we make a plea to t ...
Review Article Review Article
... a lotof remaining issues that should be solved. One is the technical problems of SiC single crystal growth process. And the other is the theoretical problem based on SiC physical properties. As the example of technical issues, in this paper, the example of design optimization for SiC sublimation gro ...
... a lotof remaining issues that should be solved. One is the technical problems of SiC single crystal growth process. And the other is the theoretical problem based on SiC physical properties. As the example of technical issues, in this paper, the example of design optimization for SiC sublimation gro ...
CLAY MINERALS
... In the framework silicates all [SiO4] tetrahedra share their corners with others, generally forming rather open three-dimensional networks. If no ion substitutes for Si, the entire framework has the composition SiO2 and all valence bonds are satisfied. When Al substitutes for Si in the tetrahedra, i ...
... In the framework silicates all [SiO4] tetrahedra share their corners with others, generally forming rather open three-dimensional networks. If no ion substitutes for Si, the entire framework has the composition SiO2 and all valence bonds are satisfied. When Al substitutes for Si in the tetrahedra, i ...
Effect of potassium nitrate on the optical and structural properties
... key elements for future photonic technologies based on the fact that photons are capable of processing information with the speed of light. Due to this fact, the rapid development of optical communication systems has led to a demand for non linear optical materials of high structural and optical qua ...
... key elements for future photonic technologies based on the fact that photons are capable of processing information with the speed of light. Due to this fact, the rapid development of optical communication systems has led to a demand for non linear optical materials of high structural and optical qua ...
X04704145151
... elements for future photonic technologies based on the fact that photons are capable of processing information with the speed of light. Researchers have been searching for new and efficient NLO materials since SHG was first observed in single crystals of quartz by Franken et al in 1961[1]. In the be ...
... elements for future photonic technologies based on the fact that photons are capable of processing information with the speed of light. Researchers have been searching for new and efficient NLO materials since SHG was first observed in single crystals of quartz by Franken et al in 1961[1]. In the be ...
X-ray crystallography
X-ray crystallography is a tool used for identifying the atomic and molecular structure of a crystal, in which the crystalline atoms cause a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their disorder and various other information.Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various materials, especially minerals and alloys. The method also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystallography is still the chief method for characterizing the atomic structure of new materials and in discerning materials that appear similar by other experiments. X-ray crystal structures can also account for unusual electronic or elastic properties of a material, shed light on chemical interactions and processes, or serve as the basis for designing pharmaceuticals against diseases.In a single-crystal X-ray diffraction measurement, a crystal is mounted on a goniometer. The goniometer is used to position the crystal at selected orientations. The crystal is bombarded with a finely focused monochromatic beam of X-rays, producing a diffraction pattern of regularly spaced spots known as reflections. The two-dimensional images taken at different rotations are converted into a three-dimensional model of the density of electrons within the crystal using the mathematical method of Fourier transforms, combined with chemical data known for the sample. Poor resolution (fuzziness) or even errors may result if the crystals are too small, or not uniform enough in their internal makeup.X-ray crystallography is related to several other methods for determining atomic structures. Similar diffraction patterns can be produced by scattering electrons or neutrons, which are likewise interpreted by Fourier transformation. If single crystals of sufficient size cannot be obtained, various other X-ray methods can be applied to obtain less detailed information; such methods include fiber diffraction, powder diffraction and (if the sample is not crystallized) small-angle X-ray scattering (SAXS).If the material under investigation is only available in the form of nanocrystalline powders or suffers from poor crystallinity, the methods of electron crystallography can be applied for determining the atomic structure.For all above mentioned X-ray diffraction methods, the scattering is elastic; the scattered X-rays have the same wavelength as the incoming X-ray. By contrast, inelastic X-ray scattering methods are useful in studying excitations of the sample, rather than the distribution of its atoms.