A new method of highly accurate orientation of single crystals on a standard powder diffractometer

1994 ◽  
Vol 27 (5) ◽  
pp. 703-709 ◽  
Author(s):  
E. Michalski
Keyword(s):  
Single Crystals ◽  
Crystal Orientation ◽  
Frequency Control ◽  
Atomic Plane ◽  
High Accuracy ◽  
New Method ◽  
General Measure ◽  
Annual Symposium ◽  
Standard Powder ◽  
Plate Face

A new method of obtaining high accuracy in a diffractometer refinement of a single-crystal orientation is presented in this paper. The primary errors in goniometer orientations are caused by the fact that, whereas the measurement required is the angle between the atomic plane and the plate face, goniometers in general measure the angle between the atomic plane and a plane defined by the goniometer, which is not necessarily parallel to the plate face. The methods of correcting for these inaccuracies associated with the goniometer orientations that have been used and cited so far are based on the laser-assisted system described by Vig [Proc. 29th Annual Symposium on Frequency Control (1975), pp. 240–247]. The method described in this paper allows one to eliminate these errors by a specially invented method of measurements and calculations without a laser-assisted system or any other additional instruments.

scholarly journals Stellar magnetic imaging from spectropolarimetric data

1996 ◽  
Vol 176 ◽  
pp. 53-60 ◽  
Author(s):  
J.-F. Donati
Keyword(s):  
Small Amplitude ◽  
High Accuracy ◽  
Spectral Lines ◽  
New Method ◽  
Doppler Imaging ◽  
Magnetic Imaging ◽  
Active Stars ◽  
Surface Fields ◽  
Very High

In this paper, I will review the capabilities of magnetic imaging (also called Zeeman-Doppler imaging) to reconstruct spot distributions of surface fields from sets of rotationnally modulated Zeeman signatures in circularly polarised spectral lines. I will then outline a new method to measure small amplitude magnetic signals (typically 0.1% for cool active stars) with very high accuracy. Finally, I will present and comment new magnetic images reconstructed from data collected in 1993 December at the Anglo-Australian Telescope (AAT).

A Design of High-Accuracy Displacement Measurement Instrument from Principles of Optics

2012 ◽  
Vol 170-173 ◽  
pp. 2924-2928
Author(s):  
Sheng Biao Chen ◽  
Yun Zhi Tan
Keyword(s):  
Measurement Instrument ◽  
High Accuracy ◽  
Mechanical Tests ◽  
Total Reflection ◽  
Displacement Measurement ◽  
New Method ◽  
Water Volume ◽  
Water Drainage ◽  
Accuracy Of Measurement ◽  
Better Than

In order to measure the water drainage volume in soil mechanical tests accurately, it develop a new method which is based on principles of optics. And from both physical and mathematic aspects, it deduces the mathematic relationship between micro change in displacement and the increment projected on screen. The result shows that total reflection condition is better than refraction condition. What’s more, the screen could show the water volume micro variation clearly, so it can improve the accuracy of measurement.

scholarly journals Barycentric prolate interpolation and pseudospectral differentiation

2021 ◽  
Author(s):  
Yan Tian
Keyword(s):  
Boundary Value Problem ◽  
Convergence Rates ◽  
Boundary Value ◽  
High Accuracy ◽  
Second Order ◽  
New Method ◽  
Numerical Examples ◽  
Helmholtz Problem ◽  
Collocation Scheme

AbstractIn this paper, we provide further illustrations of prolate interpolation and pseudospectral differentiation based on the barycentric perspectives. The convergence rates of the barycentric prolate interpolation and pseudospectral differentiation are derived. Furthermore, we propose the new preconditioner, which leads to the well-conditioned prolate collocation scheme. Numerical examples are included to show the high accuracy of the new method. We apply this approach to solve the second-order boundary value problem and Helmholtz problem.

A New Method for Aggregate Proportion Design of Mixture

2012 ◽  
Vol 178-181 ◽  
pp. 1250-1253
Author(s):  
Yu Hua Li ◽  
Kai Huang ◽  
Ying Zhen Gao
Keyword(s):  
Iterative Algorithm ◽  
Accurate Result ◽  
High Accuracy ◽  
New Method ◽  
Equation Method ◽  
Normal Equation ◽  
Improved Method ◽  
Mixture Ratio ◽  
Target Value ◽  
Initial Target

When we make design of mixture ratio, we always use normal equation method (NEM), but the solution value of that method may doesn’t meet our demand. When we use the new method that proposed in this paper, we can solve the problem. The new method makes an improvement for NEM. By iterative algorithm, the new method uses the gradation data calculated by NEM as initial target value, canceling the relevant aggregate if the result of proportion is negative, and setting the gradation to the boundary value if the target value goes beyond limits. According to the adjusted object value, using NEM again, the new aggregate proportion can be solved. Then the new gradation of mixture will come into being the next target value. Finally, the accurate result will meet our need. The new improved method has good engineering applicability and high accuracy

Adaptive Verspannung von Zahnstange-Ritzel-Antrieben*/Adaptive preloading for rack-and-pinion-drives

2019 ◽  
Vol 109 (05) ◽  
pp. 312-318
Author(s):  
T. Engelberth ◽  
A. Verl
Keyword(s):  
Machine Tools ◽  
Energy Demand ◽  
High Accuracy ◽  
Drive System ◽  
New Method ◽  
Large Machine ◽  
Production Facilities

Zahnstange-Ritzel-Antriebe werden vorwiegend in großen Werkzeugmaschinen eingesetzt. Um die hohen Genauigkeitsanforderungen moderner Produktionsanlagen zu erreichen, werden diese Antriebe elektrisch verspannt. Die Verspannung ist konstant. Dieser Beitrag beschreibt eine neuartige Methode, die sogenannte adaptive Verspannung. Ziel ist es, den Energiebedarf und die Belastung des Antriebssystems durch Anpassung der Verspannung während des Betriebs zu reduzieren, ohne die Genauigkeit zu beeinflussen.   Rack-and-pinion-drives are mostly used in large machine tools. To achieve the high accuracy specifications of modern production facilities, these drives are electrically preloaded. The preload is constant. This article describes a new method of so-called adaptive preloading. The aim is to reduce energy demand and wear of the drive system by adjusting the preload during operation without affecting the accuracy.

Lattice-constant and stress measurement in single crystals: a new method

2005 ◽  
Vol 38 (4) ◽  
pp. 678-684 ◽  
Author(s):  
Balder Ortner
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Lattice Constant ◽  
Stress Measurement ◽  
New Method ◽  
Lattice Plane ◽  
X Ray ◽  
Advantages And Disadvantages

A method for the X-ray determination of lattice-plane distances is given. Similar to Bond's method, it is based on the measurement of rocking curves, with some advantages and disadvantages compared with the former method. The new method is especially designed for single-crystal stress measurement. Its usefulness is demonstrated in two examples of lattice-constant and stress measurement.

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