bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microhardness of single crystals of the calomel family
Authors: Barta Č. , Barta Č. , Brožek V. , Hájek B. 
Published: July 2007

AbstractMicrohardness of Hg2Cl2, Hg2Br2 and Hg2I2 single crystals has been measured on (001) and (110) faces using the indenter after Vickers. It has been found that the microhardness of the first two homologues differs only slightly whereas the iodide is considerably softer: by about 20% on the (001) face and by about 30% on the (110) face. The average microhardness value, calculated from the values obtained on gradually rotating the indenter over 360° on the (001) face, is for Hg2Cl2 and Hg2Br2 practically equal to the microhardness of NaCl (20.3 and 19.4 compared to 19.6 · 107 Pa). The average microhardness of the (110) face is for Hg2Cl2 and Hg2Br2 about 2 × lower and for Hg2I2 about 2.6 × lower than that of the (001) face. In the case of Hg2Cl2 the microhardness of the (001) face has been also calculated from crystallochemical parameters and the results have been found to be in good agreement with the value obtained experimentally for the orientation of the indenter's diagonal parallel to the [100] direction, where the data is the least influenced by the elasticity of the sample (16.6 compared to 18.6 · 107 Pa).
Electron optical identification of precipitations in silicon semiconductor devices
Authors: Pasemann M. , Barna Á. , Werner P. , Hagel H.‐J. 
Published: July 2007

AbstractIn silicon MOS semiconductor devices precipitations were observed by TEM in the boron‐diffused regions. They were identified by using selected area diffraction, high resolution lattice plane imaging, Auger spectroscopy and microanalysis of X‐rays. The results lead to the conclusion that these particles consist of polycrystalline silicon and that oxygen and nitrogen, probably carbon too are concentrated inside the particles. The formation of these precipitations is only due to the technological process of the device manufactoring and does not depend on the silicon starting material.
Wave mechanism of the effect of external fields on crystallization
Authors: Kuznetsov D. A. , Hodorowicz S. , Krymova W. G. 
Published: July 2007

AbstractOver the region of the electric double layer of the system solution‐crystal, electroacoustic waves are generated by thermal movements of molecules and ions. Electrostatic field of the waves picks out crystal‐forming particles affecting thereby the rate of their deposition. The effect is controlled by the ratio of the frequency of the waves to that of vibrations of molecules in the crystal lattice. When an external variable electric field and a static magnetic field are applied to the system, the latter brings about anisotropy of generation of the electrostatic wave (in the field direction only) and appearance of another wave, transverse to the field, of the frequency higher than that of the longitudinal wave. As a result, asymmetry is produced in the growth rate of orthogonal faces of a crystal.
On the Quantum Theoretical Calculation of Activation Energies for the Self‐Diffusion of Single Atoms and the Diffusion of Adatoms on Metal Surfaces (I)
Authors: Winzer A. 
Published: July 2007

AbstractBy application and modification of the equation given by A. Einstein for calculating the internal oscillation energy of crystals, the activation energies for the self‐diffusion of single atoms on the metal surfaces of Rh, Pt, and for the surfaces diffusion of adatoms on metal surfaces were calculated on the basis of quantum theory from the surface Debye frequency and the bulk Debye frequency, neglecting the frequency distribution.A comparison of the activation energies calculated by quantum theory with the experimental values of the literature obtained by the field‐ion microscope shows a relatively good agreement for the single crystal surfaces and temperature ranges. The calculation showed a strong increase of the activation energies for the self‐diffusion at higher temperatures and a relatively great dependence on the respective crystal surface of the metal. Analogous results were also obtained for the surface diffusion of adatoms on the metals.
Structural Changes during Post‐Ageing of an Al‐Zn (15 at.%) Alloy between 125 °C and 215 °C
Authors: Löffler H. , Kroggel R. , Kabisch O. 
Published: July 2007

AbstractThe structural changes going on in an AlZn (15 at.%) alloy postaged between 125 °C and 215 °C after pre‐ageing between 20 °C and 90 °C (till start rs = (20…︁ 55) Å are obtained) were followed by means of XSAS‐investigations. The main results are the following:

An increase of rs does not favour the growth of the precipitates during the reversion treatment.
At later reversion times the happening is obviously independent of the pre‐history of the samples.
The integral intensity is decreasing with increase of Trev, but the mean distance (d)‐size (rG) relation between the precipitates is not changed remarkably up to Trev ≈ 200 °C in the early reversion stage.
Conclusions from this behaviour are drawn.
Possibilities for In‐situ Observation of Basic Deformation Processes and of Other Dynamic Processes
Authors: Imura T. 
Published: July 2007

AbstractThe purposes of this paper are to discuss the possibilities of HVEM in‐situ observation for deriving meaningful results on basic deformation processes by illustrating some examples which have been obtained so far and to assess the capabilities of this method to investigate crystal deformation as well as other dynamic processes. First, the experimental procedures developed by our group in Nagoya to study the dynamic behaviour of dislocations are introduced. Research subjects which have been studied effectively by this method so far are illustrated. The lower safety limit of specimen thickness for deriving information typical of bulk materials, the effects of size and free surfaces of a specimen and the effects of electron irradiation etc. are to be discussed to assess the validity of in situ observation of dislocation behaviours. Some prospects on new applications and extensions of in‐situ HVEM for physical and materials research are to be presented, including possibilities for in‐situ observation of other subjects such as diffusion, environmental effects, interface reaction, chemical reaction, defect formation during growing or processing of semi‐conductors, surface treatment and micro fabrication by electron beam etc.
Image Recording by TV Technique
Authors: Herrmann K.‐H. , Krahl D. , Rust H.‐P. 
Published: July 2007

AbstractFernseh‐Bildverstärkeranlagen mit Speichergeräten lassen sich für die Auslesung und Verarbeitung von EM‐Bildern in Echtzeit einsetzen. Anhand des Einzelelektronensignals und der Detection Quantum Efficiency (DQE) werden die Dimensionierungsgrundsätze für den Aufbau derartiger Anlagen erläutert und für verschiedene spezielle Systeme geprüft. Während bei hohen Endbildstromdichten ein vom Dynamikumfang der Kameraröhre abhängiger Abfall der DQE in Kauf genommen werden muß, können mit ausreichender optoelektronischer Vorverstärkung bei mittleren Stromdichten Werte von mehr als 0.80 erzielt werden. Der Idealdetektor (DQE = 1) wird bei kleinen Stromdichten mit digitaler Verarbeitung und Speicherung erreicht.
In‐situ HVEM Investigation of Processes Leading to Fracture in Metals
Authors: Wilsdorf H. G. F. 
Published: July 2007

AbstractThe unique features of in‐situ straining to fracture in high voltage electron microscopes have been outlined. Phenomena pertinent to the ductile fracture of metals have been reviewed as they relate to the study of rupture in the microstructural regime. Experimental observations on pure single crystals of silver, α‐iron, and beryllium during fracture have been reported and analyzed. The fracture mechanism can be subdivided into the sequence microvoid initiation, void growth, and void coalescense. It is proposed to distinguish between a primary and a secondary sequence. The latter is applicable to ligament fracture which constitutes the final separation. It was concluded that dislocation cell walls and other boundaries are the initiation sites for microcracks in pure metals and alloys.
Reduction and Oxidation Effects in Metal Oxide Catalysts
Authors: Gai P. L. , Goringe M. J. 
Published: July 2007

AbstractThe behaviour of metal oxide catalysts in a variety of atmospheres is described. In particular the defect structures found in MoO3 under reducing, reoxidising and mixed atmospheres are detailed. Surface relaxation defects (∼ 80 °C), surface domains (120 – 350 °C) and crystallographic shear planes (∼ 380 °C) all occur under reducing atmospheres, being differently resistant to reoxidant to reoxidation. In propylene‐oxygen mixtures the CSPs appear to be unstable.
Submicroscopic Defects in Metals and their Influence on HVEM In‐situ Experiments
Authors: Kiritani M. , Urban K. 
Published: July 2007

AbstractRecent high‐voltage electron microscopy has provided evidence that substantial submicroscopic changes may occur in specimens examined in the HVEM under conditions where no visible radiation damage occurs. These are the introduction of vacancies by plastic deformation, rapid accumulation of invisible vacancy clusters by electron irradiation, and radiation‐induced contamination and refining of materials. These processes are analysed in terms of defect interactions and the consequences for in‐situ experiments are discussed.
Dielectric reorientation of smectic C, F and I phases
Authors: Pelzl G. 
Published: July 2007

AbstractAs shown for 4 liquid crystalline substances also smectic F and smectic I phases may be reoriented by an electric field similar to a smectic C phase. The threshold voltage of the effect was determined approximately. For one substance the tilt angle of the smectic C and I phase could be measured by means of the dielectric reorientation.
On the chemical transport of molybdenum dioxide with tellurtetrahalogens (I). The Transport System MoO2/TeBr4
Authors: Ritschel M. , Oppermann H. 
Published: July 2007

AbstractA report is given on the transport behaviour of MoO2 with TeBr4. The fundamentals for the calculation of the gaseous phase composition above a solid phase are explained in the system Mo/O/Te/X. The calculated transport behaviour is compared with the experimental results, and the crystal habit of the obtained MoO2 monocrystals is described.
Generation of dislocations on polished surfaces of dislocation free silicon wafers
Authors: Fischer W. , Heymann G. 
Published: July 2007

AbstractThis paper describes investigations into the influence of wafer defects (surface defects) on the generation of process induced crystal defects in dislocation‐free n‐type silicon material of both Czochralski and zone‐floating techniques. The surface defects are artificial defects, which were produced by scratching with definite forces. The behaviour of scratched silicon surfaces as well as that of scratched and polished silicon surfaces was studied at room temperature and after heat treatment. The experimental results are discussed.
Stability of dislocations in MgO single crystals at high temperatures
Authors: Moriyoshi Y. , Ikegami T. , Matsuda Sh. , Sekikawa Y. , Shirasaki Sh. 
Published: July 2007

AbstractThe dislocation structures of MgO single crystals annealed at 1900 °C for 3 hrs and at 2000°C for 1 hr were observed electron microscopically, and it was found that the following reactions took place at high temperatures: a/2 〈110〉 + a/2 [110], = a [100], a/2 [110] + a/2 〈1101〉 = a/2 [011]. The resultant dislocations were sessile. Their interaction with impurities would make the subgrain boundaries stable.
Structure and morphology of oxide deposition on SiO2 (I) correlations between parameters of layer formation and structure
Authors: Bräuer K. , Meyer K. , Müller B. , Müller E. 
Published: July 2007

AbstractThe oxides of Ge, Sn and Ti were produced by reaction of the adequate metal tetrachlorides in dependence on reaction parameters (pressure, temperature, time) on crystalline and non‐crystalline SiO2 substrates. Structure and morphology of the formed oxides were investigated by electron diffraction and electron microscopy. In dependence on the reaction conditions results on the degree of crystallisation and on the particle size distribution could be received. On the basis of the obtained results of investigations conceptions for the mechanism of layer formation were derived.
Investigation of dislocation kinetics in α‐Fe monocrystals with the help of etching technique
Authors: Reinhold Ch. , Wuttke W. 
Published: July 2007

AbstractResults of the etching technique concerning dislocation arrangements in regions near the surface are introduced after tribomechanical loading on (001) surfaces of α‐Fe‐monocrystals. Moreover, the load stress field related to the critical shear stress is calculated and discussed. For the etching of grown in and newly developed dislocations a solution of 2% nital was used.
Kinetics of FCC and diamond type binary crystal growth (I) lattice model and kinetic equations
Authors: Cherepanova T. A. 
Published: July 2007

AbstractThe lattice model is presented for describing the growth kinetics of binary crystals with various symmetry of crystallographic lattices (for example, ‐fcc, ‐bcc, simple cubic, diamond type). The system of kinetic equations of growth of binary crystal faces for different crystallographic face orientations is obtained. The discussion is given concerning applicability of the interphase model “with overhangs” and “without overhangs”.
The detection of impurities on metallic surfaces by means of the electron energy loss spectroscopy
Authors: Heyroth W. 
Published: July 2007

AbstractThe energy analysis of backscattered low‐energy monochromatic electrons is used to investigate the appearances on crystal surfaces in the vacuum during thermal treatment. Up to 500 K hydrocarbons can be detected by electronic excitation. In the interval from 600 K to 1100 K the presence of a carbon‐contamination layer follows from the excitations of plasmons. The thickness of the layer influences the ratio of the elastically and inelastically backscattered electrons. The material analysis of the clean surfaces due to temperatures above 1200 K is performed by the excitations of the upper inner atomic shells.
Study of the Raman Polarization Spectra of the Single Crystal Phillipsite
Authors: Pechar František 
Published: July 2007

AbstractThe Raman polarization spectra of a single crystal of natural phillipsite in the wave number region 50–4000 cm−1 were measured at laboratory temperature. The vibrations observed in analysis of the measured polarization spectra can basically be divided into 4 groups: a) H2O‐vibrations, b) Internal vibrations of bonds within the (Al, Si)O4 tetrahedra, c) External vibrations between tetrahedra, d) Optical translational modes of the crystal lattice.
Growth of gallium antimonide epitaxial layers on indium arsenide substrates
Authors: Pramatarova L. D. , Tretjakov D. N. 
Published: July 2007

AbstractIn the present work the possibility is demonstrated of growing gallium antimonide epitaxial layers on indium arsenide substrates using the liquid phase epitaxial (LPE) method.The influence is nivestigated of the growth conditions on the morphology of the surface and interface of the epitaxial structures InAsGaSb. The optimum technological regimes for growth of heterostructures in the system InAsGaSb are found.
Evaluation of the predictive performance of biased regression estimators
Authors: Friedman David J. , Montgomery Douglas C. 
Published: July 2007

AbstractRegression models are widely used in forecasting, either directly as prediction equations, or indirectly as the basis of other procedures. The predictive performance of a regression model can be adversely affected by both multicollinearity and high‐leverage data points. Although biased estimation procedures have been proposed as an alternative to least squares, there has been little analysis of the predictive performance of the resulting equations. This paper discusses the predictive performance of various biased estimators, emphasizing the concept that the predictive region, as well as the strength of the multicollinearity, dictates the choice of appropriate coefficient estimators.
Linear constraints and the efficiency of combined forecasts
Authors: Clemen Robert T. 
Published: July 2007

AbstractStudies of combined forecasts have typically constrained the combining weights to sum to one and have not included a constant term in the combination. In a recent paper, Granger and Ramanathan (1984) have argued in favour of an unrestricted linear combination, including a constant term. This paper shows that for the purpose of prediction it may make sense to impose restrictions on the combining model because of potential increases in forecasting efficiency. Empirical results show that small gains in forecasting efficiency can be obtained by restricting the linear combination of GNP forecasts from four econometric models.
Time series forecasts and extra‐model information
Authors: Pankratz Alan 
Published: July 2007

AbstractOften a forecaster has supplementary information (e.g. field reports or forecasts from another source) that cannot be included directly in a time series model. Especially interesting are cases where this information is given at time intervals that are different from those of the time series model forecasts. Previous authors have considered a numerical and a model‐based statistical method for combining extra‐model information of this type with ARIMA model forecasts. This paper extends both methods to vector ARMA model forecasts and dynamic regression (transfer function) model forecasts. It is also shown that a Lagrange multiplier numerical procedure arises as a special case of the model‐based procedure. An empirical example is given.
Uncertainty, identifiability and the propagation of prediction errors: A case study of lake ontario
Authors: Beck M. B. , Halfon E. 
Published: July 2007

AbstractMost models of environmental systems can be expected to suffer, to a varying extent, from a lack of identifiability. Overparameterization seems both intrinsic and an intractable problem. As a result, interpretation of past observed behaviour through a model is ambiguous, and this will have obvious implications for any predictions of future behaviour. There has been much study of this issue of uncertainty in environmental modelling, yet very limited investigation of its consequences in the use of larger‐scale models. The paper examines some of these consequences for a model of the carbon and phosphorus cycles in Lake Ontario having 24 state variables and thirteen parameters. Filtering theory is used to provide both the conceptual framework for the analysis and a specific, recursive algorithm for the propagation of a variance‐covariance matrix of state prediction errors. Special attention is given to examining the ambiguities that may arise in the making of predictions, and the possibility of generating contradictory statements about future behaviour is introduced. It is found that with this relatively large model the propagation of prediction error variances is insensitive to the degree of correlation among the parameter‐estimation errors and to changes of the nominal estimated values of small subsets of parameters.
Accommodating structural change in environmental systems: The approach of qualitative simulation
Authors: Seixas M. Julia F. , Camara Antonio , Antunes Maria Paula , Pinheiro Manuel 
Published: July 2007

AbstractIn environmental systems forecasting is particularly relevant if one is concerned with structural changes in the system. The term 'structure refers to how the components of a system are arranged together (Kuipers, 1985b). Each component has an associated behaviour and the behaviour of the system as a whole results from the interaction between these components through specified connections. The structure of the system is defined by a range of values for its components. If at least one component exceeds some value that bounds this component's range, a new structure is achieved. Environmental systems are prone to structural change, due to endogenous and usually exogenous agents. This paper introduces a method for considering structural change in the framework of dynamic qualitative simulation. Forecasting of structural change can, in principle, be accommodated by using learning mechanisms. An application to an environmental system is presented for illustrative purposes.
Forecasting with generalized bayesian vector auto regressions
Authors: Rao Kadiyala K. , Karlsson Sune 
Published: July 2007

AbstractThe effects of using different distributions to parameterize the prior beliefs in a Bayesian analysis of vector autoregressions are studied. The well‐known Minnesota prior of Litterman as well as four less restrictive distributions are considered. Two of these prior distributions are new to vector autoregressive models. When the forecasting performance of the different parameterizations of the prior beliefs are compared it is found that the prior distributions that allow for dependencies between the equations of the VAR give rise to better forecasts.
A new parallel algorithm for the n‐Job, m‐machine flow‐shop scheduling problem
Authors: Okamoto Shusuke , Watanabe Ichie , Iizuka Hajime 
Published: July 2007

AbstractThis paper describes a new parallel algorithm for solving the m‐machines, n‐jobs flow‐shop scheduling problem as well as its implementation on a distributed memory multiprocessor. The algorithm is basically a parallelization of the usual branch‐and‐bound method. It also takes advantage of the all‐search method to keep the efficiency of parallel processing reasonably high when subproblems become smaller than a certain size. The performance evaluation is done by comparing the parallel execution of this algorithm on the nCUBE2 multiprocessor and the sequential execution of the branch‐and‐bound with depth‐first search algorithm. The result shows that the mean speedup ratio for some conditions of the problem is more than the number of processors, and the mean speedup ratio for the conditions on which the sequential executions complete quickly is not smaller than 1.
A high‐speed MRI simulator using the transition matrix method and periodicity of magnetization
Authors: Taniguchi Yo , Nakaya Chitose , Bito Yoshitaka , Yamamoto Etsuji 
Published: July 2007

AbstractAn MRI simulator is a tool for understanding MR phenomena and developing new pulse sequences, which determine picture quality and information included in MR signals. Conventional simulators calculate the Bloch equations approximately to reduce the computation time. This paper presents a technique for solving the equations exactly at high speed and for creating images. The processing time is made practical by using the transition matrix method and the periodicity of the magnetization.
Novice program recognition/diagnosis system based on goal/plan concepts
Authors: Kaijiri Kenji 
Published: July 2007

AbstractStudies on program understanding/recognition have been conducted from various points of view, including debugging. However, the target, the range and the kind of recognition, differ according to objectives. A new problem description method and a new recognition method whose objective is to help novices learn program design and debugging is proposed here. This method has the following characteristics:

It uses the algorithm level problem description. It is called the problem solution tree.
The problem solution tree has positional information regarding goals.
It uses a variety of matching methods to enable matching with many erroneous student programs.
It uses a partial recognition strategy to diagnose programs with which full matching failed.
The system recognized that approximately 85 percent of the novice samples are not well formed.