scholarly journals Dynamics of a spherical object of uniform density in an expanding universe

2013 ◽  
Vol 88 (4) ◽  
Author(s):  
Roshina Nandra ◽  
Anthony N. Lasenby ◽  
Michael P. Hobson
Keyword(s):  
Uniform Density ◽  
Expanding Universe ◽  
Spherical Object

Modeling of Shock Propagation in Non-uniform Density Media

2020 ◽  
Author(s):  
Yifeng Tian ◽  
Farhad A. Jaberi ◽  
Daniel Livescu
Keyword(s):  
Shock Propagation ◽  
Uniform Density

Spherical object recognition based on the number of contour edges extracted by fitting and convex hull processing

2020 ◽  
pp. 095440702096950
Author(s):  
Bochang Zou ◽  
Huadong Qiu ◽  
Yufeng Lu
Keyword(s):  
Convex Hull ◽  
Target Object ◽  
Identification Accuracy ◽  
Detection Accuracy ◽  
Morphological Operations ◽  
Circle Detection ◽  
Spherical Object ◽  
Single Feature ◽  
Contour Fitting ◽  
Rgb Images

The detection of spherical targets in workpiece shape clustering and fruit classification tasks is challenging. Spherical targets produce low detection accuracy in complex fields, and single-feature processing cannot accurately recognize spheres. Therefore, a novel spherical descriptor (SD) for contour fitting and convex hull processing is proposed. The SD achieves image de-noising by combining flooding processing and morphological operations. The number of polygon-fitted edges is obtained by convex hull processing based on contour extraction and fitting, and two RGB images of the same group of objects are obtained from different directions. The two fitted edges of the same target object obtained at two RGB images are extracted to form a two-dimensional array. The target object is defined as a sphere if the two values of the array are greater than a custom threshold. The first classification result is obtained by an improved K-NN algorithm. Circle detection is then performed on the results using improved Hough circle detection. We abbreviate it as a new Hough transform sphere descriptor (HSD). Experiments demonstrate that recognition of spherical objects is obtained with 98.8% accuracy. Therefore, experimental results show that our method is compared with other latest methods, HSD has higher identification accuracy than other methods.

scholarly journals China’s first step towards probing the expanding universe and the nature of gravity using a space borne gravitational wave antenna

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Keyword(s):  
Gravitational Wave ◽  
Hubble Constant ◽  
Gravitational Wave Detector ◽  
Expanding Universe ◽  
Satellite Mission ◽  
Gravitational Wave Detection ◽  
Wave Detection ◽  
Wave Detector ◽  
Wave Antenna ◽  
Gravitational Wave Antenna

AbstractIn this perspective, we outline that a space borne gravitational wave detector network combining LISA and Taiji can be used to measure the Hubble constant with an uncertainty less than 0.5% in ten years, compared with the network of the ground based gravitational wave detectors which can measure the Hubble constant within a 2% uncertainty in the next five years by the standard siren method. Taiji is a Chinese space borne gravitational wave detection mission planned for launch in the early 2030 s. The pilot satellite mission Taiji-1 has been launched in August 2019 to verify the feasibility of Taiji. The results of a few technologies tested on Taiji-1 are presented in this paper.

scholarly journals Atomic Layer Deposition of Ni-Co-O Thin-Film Electrodes for Solid-State LIBs and the Influence of Chemical Composition on Overcapacity

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 907
Author(s):  
Yury Koshtyal ◽  
Ilya Mitrofanov ◽  
Denis Nazarov ◽  
Oleg Medvedev ◽  
Artem Kim ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Atomic Layer Deposition ◽  
Nickel Oxide ◽  
Cobalt Oxide ◽  
Lithium Ion ◽  
Atomic Layer ◽  
Metallic Nickel ◽  
Uniform Density ◽  
Oxide Content ◽  
Layer Deposition

Nanostructured metal oxides (MOs) demonstrate good electrochemical properties and are regarded as promising anode materials for high-performance lithium-ion batteries (LIBs). The capacity of nickel-cobalt oxides-based materials is among the highest for binary transition metals oxide (TMOs). In the present paper, we report the investigation of Ni-Co-O (NCO) thin films obtained by atomic layer deposition (ALD) using nickel and cobalt metallocenes in a combination with oxygen plasma. The formation of NCO films with different ratios of Ni and Co was provided by ALD cycles leading to the formation of nickel oxide (a) and cobalt oxide (b) in one supercycle (linear combination of a and b cycles). The film thickness was set by the number of supercycles. The synthesized films had a uniform chemical composition over the depth with an admixture of metallic nickel and carbon up to 4 at.%. All samples were characterized by a single NixCo1-xO phase with a cubic face-centered lattice and a uniform density. The surface of the NCO films was uniform, with rare inclusions of nanoparticles 15–30 nm in diameter. The growth rates of all films on steel were higher than those on silicon substrates, and this difference increased with increasing cobalt concentration in the films. In this paper, we propose a method for processing cyclic voltammetry curves for revealing the influence of individual components (nickel oxide, cobalt oxide and solid electrolyte interface—SEI) on the electrochemical capacity. The initial capacity of NCO films was augmented with an increase of nickel oxide content.

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