Symmetric Distortion Correction in Asphere Manufacturing

2013 ◽  
Vol 552 ◽  
pp. 158-161
Author(s):  
Jian Zhang ◽  
Lei Dai
Keyword(s):  
Direct Measurement ◽  
Distortion Correction ◽  
Experimental Results ◽  
Aspheric Surface ◽  
Internal Imaging ◽  
Imaging Optics

A method of symmetric distortion correction is described and successfully applied to correct the distortion mapping errors caused by CGH as well as internal imaging optics. The aspheric surface is 160 mm in diameter and has a maximum departure of 145 μm. According to the model established by the fiducial spots on the aspheric surface, we show experimental results after direct measurement and distortion-corrected error map respectively. The results show that the method of symmetric distortion correction is useful and effective.

scholarly journals Experimental Comparison of Outdoor Baseline Measurements by Different Methods

2019 ◽  
Vol 131 ◽  
pp. 01057
Author(s):  
Youyi Gu ◽  
Li Wang ◽  
Fengzhuo Xiang ◽  
Wen Ouyang ◽  
Lixing Jiang
Keyword(s):  
Direct Measurement ◽  
High Precision ◽  
Optical Measurement ◽  
Experimental Results ◽  
Experimental Comparison ◽  
Total Station ◽  
Length Standard ◽  
Gnss Receivers ◽  
Surveying And Mapping

Outdoor baseline is the special length standard in the field of surveying and mapping, it can be used to verify the addition and multiplication constants of the total station and other photoelectric rangefinders. In order to ensure the authenticity, accuracy and reliability of verification results, conducting outdoor baseline traceability periodically is essential. At present, direct measurement by 24m invar tape or high precision electro-optical measurement is mainly used to achieve the traceability of outdoor baseline in China. Based on Shenyang baseline field, high precision rangefinder μ-base, 24m invar tape and high precision GNSS receivers are used for comparison experiments, and the experimental results are analyzed.

A Direct Measurement Method of Building’s Shunt Coefficient

2012 ◽  
Vol 241-244 ◽  
pp. 885-888
Author(s):  
Xiao Chun Zhang ◽  
Xiu Bin Sun ◽  
Xiang Yong Mou
Keyword(s):  
Direct Measurement ◽  
Measurement Method ◽  
Pulse Current ◽  
Induction Coil ◽  
Experimental Results ◽  
Current Generator ◽  
Digital Oscilloscope ◽  
Direct Measurement Method

The shunt coefficient of a model of constructions was measured by a pulse current generator, an induction coil, a digital oscilloscope. The experimental results demonstrate that the method is effective, the distribution of pulse current in a buildings can be directly measured without damage.

On-machine truing of diamond wheel and high-efficiency grinding of monocrystal silicon for aspheric surface

2016 ◽  
Vol 231 (1) ◽  
pp. 186-192 ◽  
Author(s):  
Bing Chen ◽  
Bing Guo ◽  
Qingliang Zhao
Keyword(s):  
Surface Quality ◽  
Material Removal ◽  
High Efficiency ◽  
Diamond Wheel ◽  
Experimental Results ◽  
Aspheric Surface ◽  
Removal Rates ◽  
Aspheric Surfaces ◽  
Silicon Carbon

To realize the high-efficiency grinding of the aspheric surfaces on monocrystal silicon, a novel on-machine truing method for the resin-bonded arc-shaped diamond wheels was proposed utilizing rotary green silicon carbon rod, and then the high-efficiency grinding of the aspheric surface was performed. First, the principle of mutual-wear for truing arc-shaped diamond wheel was introduced, and the truing performance was studied. The experimental results showed that the top morphology of the trued arc-shaped wheel was precise and smooth, and the run error on the top of the trued arc-shaped wheel was reduced from 41 to 10 µm after truing. Furthermore, high-efficiency grinding experiments revealed that the surface quality of the aspheric surface increased with the increase in the average material removal rates.

Distortion Correction of a Quick Response Code Image

2013 ◽  
Vol 431 ◽  
pp. 312-317
Author(s):  
Xue Min Cheng ◽  
Qun Hao ◽  
Chao Zhang ◽  
Jian She Ma
Keyword(s):  
Detailed Analysis ◽  
Distortion Correction ◽  
Experimental Results ◽  
Qr Code ◽  
Quick Response ◽  
Response Code ◽  
Cylindrical Object ◽  
Quick Response Code ◽  
Curl Distortion ◽  
Unified Method

Distortion typically occurs when images are captured from the surface of a cylindrical object. This problem is obvious in Quick Response (QR) code images, which necessitate distortion correction for subsequent information reading. Based on a detailed analysis of this distortion, we divided it into linear distortion along the generatrix direction and curl distortion perpendicular to the generatrix direction, and proposed a unified method to correct the distortion of both components. Experimental results are given to demonstrate the feasibility and applicability of the method.

THE BOUND WATER OF WHEAT-FLOUR SUSPENSIONS

1930 ◽  
Vol 3 (6) ◽  
pp. 560-578 ◽  
Author(s):  
R. Newton ◽  
W. H. Cook
Keyword(s):  
Lactic Acid ◽  
Wheat Flour ◽  
Direct Measurement ◽  
Dry Matter ◽  
Bound Water ◽  
Experimental Results ◽  
Bread Dough ◽  
Baking Quality

The bound-water method was modified for use with flour suspensions and provided a simple means for the direct measurement of the approximate hydration of the colloidal constituents in dilute lactic acid. The average hydration of the dry matter in 15% suspensions was in the region of 40 to 50%, the value being slightly higher in washed suspensions. Starch maintained a hydration close to 30%, under all conditions investigated. The prepared proteins, in dilute lactic acid, were hydrated about 85%. The calculated hydration of the proteins as they occurred in the flour was about 100% in unwashed and 200% in washed suspensions.No significant differences were found by this method in the hydration of strong and weak flours, and it is thought that such differences as may exist are too small to be of major importance as factors in baking quality. The experimental results are harmonized with the facts concerning viscosity and the behavior of bread dough by assuming micellar aggregation of the gluten.

Device and Method for Large Size Aspheric Measurement

2010 ◽  
Vol 97-101 ◽  
pp. 4324-4327
Author(s):  
Yong Lu Zhu ◽  
Yin Biao Guo ◽  
Xiao Long Ke ◽  
Lu Shuang Chen
Keyword(s):  
Control System ◽  
Measurement System ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Detection System ◽  
Experimental Results ◽  
Aspheric Surface ◽  
Large Size ◽  
And Control

In this paper, the necessary instrument and control system called the “Large Size Four-axis Measurement System” which used for measuring large size aspheric surface have been designed and established. Then the development of semi-meridian measurement method on basis of large size four-axis detection system has been reported. The measurement paths were planed and the measurement program was performed on the IPC. The method can significantly reduced the align error caused by the aspheric center which is not coincidence with the rotation platform center. With the measurement system, an aspheric surface was successfully measured; whose radius of semi-meridian was 55 mm. The experimental results show that the developed methods are simple and rapid. The measurement accuracy can satisfy requirement of aspheric surface.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

1974 ◽  
Vol 32 ◽  
pp. 390-391
Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya
Keyword(s):  
Field Emission ◽  
Phase Contrast ◽  
Image Formation ◽  
Fresnel Diffraction ◽  
Experimental Results ◽  
Electron Gun ◽  
Scanning Microscopy ◽  
Emission Electron ◽  
Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

A new dissociation mode for dislocations in silicon

1978 ◽  
Vol 36 (1) ◽  
pp. 346-347
Author(s):  
A. Ourmazd ◽  
G.R. Booker ◽  
C.J. Humphreys
Keyword(s):  
Detailed Examination ◽  
Experimental Results ◽  
Dislocation Network ◽  
Weak Beam ◽  
Phosphorus Doped

A (111) phosphorus-doped Si specimen, thinned to give a TEM foil of thickness ∼ 150nm, contained a dislocation network lying on the (111) plane. The dislocation lines were along the three <211> directions and their total Burgers vectors,ḇt, were of the type , each dislocation being of edge character. TEM examination under proper weak-beam conditions seemed initially to show the standard contrast behaviour for such dislocations, indicating some dislocation segments were undissociated (contrast A), while other segments were dissociated to give two Shockley partials separated by approximately 6nm (contrast B) . A more detailed examination, however, revealed that some segments exhibited a third and anomalous contrast behaviour (contrast C), interpreted here as being due to a new dissociation not previously reported. Experimental results obtained for a dislocation along [211] with for the six <220> type reflections using (g,5g) weak-beam conditions are summarised in the table below, together with the relevant values.

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