3 In Situ STM Studies of Model Catalysts
... model catalyst surfaces [4-6]. Working on the compact design of the scanner probe and using high performance electronics, Frenken and coworkers [7] have recently pushed the scan rate above the video rate (",,50frame/s) on a graphite surface, with atomic resolution and an image with 256 x 256 pixels. ...
... model catalyst surfaces [4-6]. Working on the compact design of the scanner probe and using high performance electronics, Frenken and coworkers [7] have recently pushed the scan rate above the video rate (",,50frame/s) on a graphite surface, with atomic resolution and an image with 256 x 256 pixels. ...
STUDY OF THZ SURFACE WAVES (TSW)
... However, as the conductivity increases, the surface field extends so far into free space that the surface of the conductor has little confinement to the mode of surface wave. In fact, as it had been pointed out by many early researchers, in THz and the equivalent far infrared, the surface wave is di ...
... However, as the conductivity increases, the surface field extends so far into free space that the surface of the conductor has little confinement to the mode of surface wave. In fact, as it had been pointed out by many early researchers, in THz and the equivalent far infrared, the surface wave is di ...
A crucial factor in the MRS is signal to noise ratio
... discoveries concerning MRI. As the signal-to-noise ratio (SNR) and thus image resolution increases with the magnetic field strength there is a trend forward using stronger magnets. The standard clinical system is equipped with a 1.5T magnet but 3T systems also obtained an FDA approval for clinical u ...
... discoveries concerning MRI. As the signal-to-noise ratio (SNR) and thus image resolution increases with the magnetic field strength there is a trend forward using stronger magnets. The standard clinical system is equipped with a 1.5T magnet but 3T systems also obtained an FDA approval for clinical u ...
06 _chapter 2
... materials include their inherent high resistivity which results in low eddy current losses over wide frequency ranges, high magnetic permeability and stability over wide temperature ranges. For inductor cores, transformer cores and other applications where electromagnetic materials are required to o ...
... materials include their inherent high resistivity which results in low eddy current losses over wide frequency ranges, high magnetic permeability and stability over wide temperature ranges. For inductor cores, transformer cores and other applications where electromagnetic materials are required to o ...
Insulator charging by contact with metals
... of the insulator in order to be consistent with experimental results. There are, however, divergences of opinion whether the electrons are transferred only to the surface or if they penetrate into the bulk of the insulator. The surface trap theory (Bauser et. al. (1970)) and the penetration theory ( ...
... of the insulator in order to be consistent with experimental results. There are, however, divergences of opinion whether the electrons are transferred only to the surface or if they penetrate into the bulk of the insulator. The surface trap theory (Bauser et. al. (1970)) and the penetration theory ( ...
2 Ultrafast Lasers and Amplifiers
... introduced by the Ti:sapphire rod. The limiting factor on the exceptional stability of these oscillators is the pump source and here diode-pumped solid-state laser sources are rapidly replacing large expensive low-efficiency ion lasers. In parallel with improvements in oscillator technology, the tec ...
... introduced by the Ti:sapphire rod. The limiting factor on the exceptional stability of these oscillators is the pump source and here diode-pumped solid-state laser sources are rapidly replacing large expensive low-efficiency ion lasers. In parallel with improvements in oscillator technology, the tec ...
Time and Temperature Dependent Surface Tension Measurements
... by measuring the surface tension. The surface tension is measured as a function of time for different ELP concentrations from 10 nM to 50 μM and over range of temperatures from 25 to 35 ℃ using the axisymmetric drop shape analysis (ADSA). The ADSA is a method which is based on the analysis of the sh ...
... by measuring the surface tension. The surface tension is measured as a function of time for different ELP concentrations from 10 nM to 50 μM and over range of temperatures from 25 to 35 ℃ using the axisymmetric drop shape analysis (ADSA). The ADSA is a method which is based on the analysis of the sh ...
Properties of Oxide Surfaces
... to create a (110) surface (dotted lines). The stacking sequence in rutile along the (110) direction is -o-2Meo-o-o-2Meo-. one could, therefore, imagine separating the crystal to obtain a -o-2Meo, -o-2Meo-o, or -o-2Meo-o-o terminated surface. Upon those three possibilities, only a cut that yields the ...
... to create a (110) surface (dotted lines). The stacking sequence in rutile along the (110) direction is -o-2Meo-o-o-2Meo-. one could, therefore, imagine separating the crystal to obtain a -o-2Meo, -o-2Meo-o, or -o-2Meo-o-o terminated surface. Upon those three possibilities, only a cut that yields the ...
Kinetics and Diffusion Basic concepts in kinetics
... atoms of the same kind as the atoms of the crystal. Self-interstitials in most materials introduce strong deformations into the lattice and have very high formation energy, Δhfi ≈ 3Δhfv for metals. The number of equilibrium interstitials can be estimated by an equation similar to the one derived for ...
... atoms of the same kind as the atoms of the crystal. Self-interstitials in most materials introduce strong deformations into the lattice and have very high formation energy, Δhfi ≈ 3Δhfv for metals. The number of equilibrium interstitials can be estimated by an equation similar to the one derived for ...
fracture analysis of surface- and through-cracked
... is the complete elliptical integral of the second kind[l], p is the radius of the notch at point A in the Y-Z plane, and (Yis a correction factor which accounts for the influence of external boundaries. For an infinite solid (Y is equal to unity. Equation (2) is an approximate expression which fits ...
... is the complete elliptical integral of the second kind[l], p is the radius of the notch at point A in the Y-Z plane, and (Yis a correction factor which accounts for the influence of external boundaries. For an infinite solid (Y is equal to unity. Equation (2) is an approximate expression which fits ...
Mössbauer Spectrometry
... energies from the interaction between the nucleus and its neighboring electrons. The three important hyperfine interactions originate from the electron density at the nucleus (the isomer shift), the gradient of the electric field (the nuclear quadrupole splitting), and the unpaired electron density ...
... energies from the interaction between the nucleus and its neighboring electrons. The three important hyperfine interactions originate from the electron density at the nucleus (the isomer shift), the gradient of the electric field (the nuclear quadrupole splitting), and the unpaired electron density ...
Development of Holography Electron Microscope
... fields at scales in the order of tens of picometers. At this point it is essential to mention Isao Matsui, the engineer who worked in tandem with Dr. Tonomura on the development of the ultra-highvoltage holography electron microscope. Mr. Matsui, who led the development of Hitachi’s ultra-highvoltag ...
... fields at scales in the order of tens of picometers. At this point it is essential to mention Isao Matsui, the engineer who worked in tandem with Dr. Tonomura on the development of the ultra-highvoltage holography electron microscope. Mr. Matsui, who led the development of Hitachi’s ultra-highvoltag ...
Journal - AIMS Lab
... Tobermorites are a class of low calcium to silicon ratio (C/ S ! 1) calcium-silicate-hydrates (CSH), composed of pseudo-octahedrally coordinated calcium sheets sandwiched by infinite and parallel silica chains on both sides. Interlayer spacing is filled with calcium and water molecules; the amount o ...
... Tobermorites are a class of low calcium to silicon ratio (C/ S ! 1) calcium-silicate-hydrates (CSH), composed of pseudo-octahedrally coordinated calcium sheets sandwiched by infinite and parallel silica chains on both sides. Interlayer spacing is filled with calcium and water molecules; the amount o ...
The Reactivity of Colloidal Inorganic Nanoparticles
... towards an aggregated state. Although this reactivity is often undesirable (physico-chemical properties of INPs are restricted to individual particles in non-physical contact) it can be used as driving force for the formation of more complex structures either by an oriented attached mechanism or by ...
... towards an aggregated state. Although this reactivity is often undesirable (physico-chemical properties of INPs are restricted to individual particles in non-physical contact) it can be used as driving force for the formation of more complex structures either by an oriented attached mechanism or by ...
Magnetostriction of GdAg2, PrFe4As12, and GdVO3 measured with
... To determine the thermal expansion coefficient, two physical quantities (displacement and temperature) must be measured on a sample that is undergoing a thermal cycle. Three of the main techniques used for CTE measurement are dilatometry, interferometry, and thermo mechanical analysis. Optical imagi ...
... To determine the thermal expansion coefficient, two physical quantities (displacement and temperature) must be measured on a sample that is undergoing a thermal cycle. Three of the main techniques used for CTE measurement are dilatometry, interferometry, and thermo mechanical analysis. Optical imagi ...
Cao-Wang - Physical Chemistry of Solid Surfaces - Chapter 2 of Nanostrcutures and Nanomaterials.
... and the ease in getting near perfect crystal structure in nanomaterials are indicative that the impurities and defects are readily to be repelled from the interior to the surface of nanostructures and nanomaterials. At the individual nanostructure level, there are two approaches to the reduction of ...
... and the ease in getting near perfect crystal structure in nanomaterials are indicative that the impurities and defects are readily to be repelled from the interior to the surface of nanostructures and nanomaterials. At the individual nanostructure level, there are two approaches to the reduction of ...
Synthesis and characterization of pure and doped ZnO
... size of 80 nm. The increasing calcination temperature leads to the trend of increasing grain size which is believed to be affected by the promotion of crystalline phase in the powder and neck growth between particles as temperature increased. The grain size of crystallites in ZnO powders calcined at ...
... size of 80 nm. The increasing calcination temperature leads to the trend of increasing grain size which is believed to be affected by the promotion of crystalline phase in the powder and neck growth between particles as temperature increased. The grain size of crystallites in ZnO powders calcined at ...
Zeolite inclusion chemistry. Clusters, quantum dots, and polymers.
... based on rings containing 6 to 20 (in a gallophosphate) metal and oxygen atoms. Not only channels but also cage structures can be formed. There are now more than seventy different structure types known and new ones continue to emerge. Zeolites have remarkable temperature stability; survival of struc ...
... based on rings containing 6 to 20 (in a gallophosphate) metal and oxygen atoms. Not only channels but also cage structures can be formed. There are now more than seventy different structure types known and new ones continue to emerge. Zeolites have remarkable temperature stability; survival of struc ...
32. Particle detectors 1
... necessary. However, proximity-focused PMT’s, e.g. the fine-mesh types, can be used even in a high magnetic field (≥ 1 T) if the electron drift direction is parallel to the field. CMS uses custom-made vacuum phototriodes (VPT) mounted on the back face of projective lead tungstate crystals to detect s ...
... necessary. However, proximity-focused PMT’s, e.g. the fine-mesh types, can be used even in a high magnetic field (≥ 1 T) if the electron drift direction is parallel to the field. CMS uses custom-made vacuum phototriodes (VPT) mounted on the back face of projective lead tungstate crystals to detect s ...
Particle detectors
... necessary. However, proximity-focused PMT’s, e.g. the fine-mesh types, can be used even in a high magnetic field (≥ 1 T) if the electron drift direction is parallel to the field. CMS uses custom-made vacuum phototriodes (VPT) mounted on the back face of projective lead tungstate crystals to detect s ...
... necessary. However, proximity-focused PMT’s, e.g. the fine-mesh types, can be used even in a high magnetic field (≥ 1 T) if the electron drift direction is parallel to the field. CMS uses custom-made vacuum phototriodes (VPT) mounted on the back face of projective lead tungstate crystals to detect s ...
structural and luminescence properties of magnesium strontium
... time, zinc sulphide doped cobalt and copper (ZnS: Cu, Co) was considered the main phosphorescent materials. However, it has a short phosphorescence time and not stable enough during its application (Bol et al., 2002). Thus new hosts are getting much attention in order to improve the long after glow ...
... time, zinc sulphide doped cobalt and copper (ZnS: Cu, Co) was considered the main phosphorescent materials. However, it has a short phosphorescence time and not stable enough during its application (Bol et al., 2002). Thus new hosts are getting much attention in order to improve the long after glow ...
Surface Structure/Property Relationship for (001) Surface of Magnetite
... magnetic recording media.[1-6] It is also an important catalyst in ammonia synthesis, FischerTropsch synthesis, and also in high temperature water gas phase shift reactions.[7-15] In the field of geology, Fe3O4 can affect the local magnetic field as a frequently occurred magnetic material in the ear ...
... magnetic recording media.[1-6] It is also an important catalyst in ammonia synthesis, FischerTropsch synthesis, and also in high temperature water gas phase shift reactions.[7-15] In the field of geology, Fe3O4 can affect the local magnetic field as a frequently occurred magnetic material in the ear ...
Effect of external energy on atomic, crystalline and powder
... X-ray diffraction (XRD), surface area determination (BET), thermal analytical techniques such as DTA–DTG, DSC–TGA and SDTA and scanning electron microscopy (SEM). The treated powder samples exhibited remarkable changes in the powder characteristics at all structural levels starting from polycrystall ...
... X-ray diffraction (XRD), surface area determination (BET), thermal analytical techniques such as DTA–DTG, DSC–TGA and SDTA and scanning electron microscopy (SEM). The treated powder samples exhibited remarkable changes in the powder characteristics at all structural levels starting from polycrystall ...
Radiation Detection Principles and Instruments
... • Collected charge becomes independent of # of primary ionizations • Secondary ionization progresses to photoionization (photoelectric effect) • Proportionality constant no longer accurate • Not very useful range for radiation detection NET 130 ...
... • Collected charge becomes independent of # of primary ionizations • Secondary ionization progresses to photoionization (photoelectric effect) • Proportionality constant no longer accurate • Not very useful range for radiation detection NET 130 ...
An energy-based approach for estimates of the stress-strain
... notches, approximate methods were also developed, the two most used being due to the works of Neuber [3] and Glinka [4]. Both of the approaches, however, return only scalar values for stress and strain at the tip of the notch and not the stress-strain fields ahead of the notch. In many cases the str ...
... notches, approximate methods were also developed, the two most used being due to the works of Neuber [3] and Glinka [4]. Both of the approaches, however, return only scalar values for stress and strain at the tip of the notch and not the stress-strain fields ahead of the notch. In many cases the str ...
Atom probe
The atom probe was introduced at the 14th International Field Emission Symposium in 1967 by Erwin W. Müller and John Panitz. For the first time an instrument could “... determine the nature of one single atom seen on a metal surface and selected from neighboring atoms at the discretion of the observer”. Erwin Wilhelm Müller, J. A. Panitz, and S. Brooks McLane. The atom probe is closely related to the field ion microscope, the first microscopic instrument capable of atomic resolution, developed in 1951 by Erwin Wilhelm Müller.Atom probes are unlike conventional optical or electron microscopes, in that the magnification effect comes from the magnification provided by a highly curved electric field, rather than by the manipulation of radiation paths. The method is destructive in nature removing ions from a sample surface in order to image and identify them, generating magnifications sufficient to observe individual atoms as they are removed from the sample surface. Through coupling of this magnification method with time of flight mass spectrometry, ions evaporated by application of electric pulses can have their mass-to-charge ratio computed.Through successive evaporation of material, layers of atoms are removed from a specimen, allowing for probing not only of the surface, but also through the material itself. Computer methods are utilised to rebuild a three-dimensional view of the sample, prior to it being evaporated, providing atomic scale information on the structure of a sample, as well as providing the type atomic species information. The instrument allows the three-dimensional reconstruction of up to billions of atoms from a sharp tip (corresponding to specimen volumes of 10,000-10,000,000 nm3).