2,635 research outputs found
Differential measurement of atmospheric refraction with a telescope with double fields of view
For the sake of complete theoretical research of atmospheric refraction, the
atmospheric refraction under the condition of lower angles of elevation is
still worthy to be analyzed and explored. In some engineering applications, the
objects with larger zenith distance must be observed sometimes. Carrying out
observational research of the atmospheric refraction at lower angles of
elevation has an important significance. It has been considered difficult to
measure the atmospheric refraction at lower angles of elevation. A new idea for
determining atmospheric refraction by utilizing differential measurement with
double fields of view is proposed. Taking the observational principle of
HIPPARCOS satellite as a reference, a schematic prototype with double fields of
view was developed. In August of 2013, experimental observations were carried
out and the atmospheric refractions at lower angles of elevation can be
obtained by the schematic prototype. The measured value of the atmospheric
refraction at the zenith distance of 78.8 degree is , and the
feasibility of differential measurement of atmospheric refraction with double
fields of view was justified. The limitations of the schematic prototype such
as inadequate ability of gathering light, lack of accurate meteorological data
recording and lower automatic level of observation and data processing were
also pointed out, which need to be improved in subsequent work.Comment: 10 pages, 6 figure
Metal-on-metal joint bearings and hematopoetic malignancy.
To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field.This is a review of the hip arthroplasty era. We concentrate on new metal bearings, surface replacements, and the lessons not learned, and we highlight recent reports on malignancies and joint implants. A low incidence of blood malignancies has been found in bone marrow taken at prosthetic surgery. The incidence is increased after replacement with knee implants that release very low systemic levels of metal ions. A carcinogenic effect of the high levels of metal ions released by large metal-on-metal implants cannot be excluded. Ongoing Swedish implant registry studies going back to 1975 can serve as a basis for evaluation of this risk.Swedish Association of Local Authorities and Regions
Faculty of Medicine, Lund University
Stiftelsen for Bistand at Rorelsehindrade i Skane
Region Skan
Machine learning study of the relationship between the geometric and entropy discord
As an important resource to realize quantum information, quantum correlation
displays different behaviors, freezing phenomenon and non-localization, which
are dissimilar to the entanglement and classical correlation, respectively. In
our setup, the ordering of quantum correlation is represented for different
quantization methods by considering an open quantum system scenario. The
machine learning method (neural network method) is then adopted to train for
the construction of a bridge between the R\`{e}nyi discord () and the
geometric discord (Bures distance) for form states. Our results clearly
demonstrate that the machine learning method is useful for studying the
differences and commonalities of different quantizing methods of quantum
correlation
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