Structure Design and Analysis for the Spacecraft On-Orbit Replacement Unit (ORU)

2013 ◽  
Vol 437 ◽  
pp. 449-453 ◽  
Author(s):  
Xi Zhai ◽  
Xin Hong Li ◽  
Si Yin Zhou
Keyword(s):  
Complex Structure ◽  
Structure Design ◽  
Module Structure ◽  
Assembly Technology ◽  
Universal Structure ◽  
Module Structures

By using on-orbit replacement and assembly technology, some fresh ideas and methods for the design, produce and application of spacecraft were put forward. Universal structure is one of the most basic requirements of On-Orbit replacement, assembly. Module structure must obey the rules of the Operationally Responsive Space (ORS). According to the degree of spacecraft module division, two module structures were proposed, and the complex structure was analyzed to verify the correctness of it.

A high-sensitivity dual-sample synchronous detection photonic crystal fiber sensor

2021 ◽  
pp. 2150306
Author(s):  
Pibin Bing ◽  
Guifang Wu ◽  
Zhongyang Li ◽  
Sheng Yuan ◽  
Hongtao Zhang ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Complex Structure ◽  
High Sensitivity ◽  
Structure Design ◽  
Synchronous Detection ◽  
Crystal Fiber ◽  
The Core ◽  
Wavelength Sensitivity ◽  
Air Hole

The photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR) technology has flexibility in birefringence, negative dispersion, effective area and nonlinearity and has become a widely studied new fiber. However, there are many problems in the practical application of the sensor, such as complex structure design, not easy to prepare, the low sensitivity of sensing detection, narrow range of refractive index detection of analytes, which greatly limits the application range and functions of PCF sensors. To solve the above problems, this paper adopts a structure with a longer vertical distance between the D-shaped large air hole channel and the core. The energy of the core conduction mode is better limited by the cladding to transmit in the core, and the plasma mode is enhanced, which can effectively increase the wavelength sensitivity. In this paper, the hexagonal double-clad air hole structure and the D-type structure are combined to ensure a simple structure and facilitate manufacturing and production, while the wavelength sensitivity is also greatly improved. The wavelength sensitivity of the dual sample channel can reach up to 16200 nm/RIU and 15800 nm/RIU, which has broad application prospects in the field of high-sensitivity detection.

Using a cluster approach in the regional agro-industrial complex' structure design

2021 ◽  
Vol 19 (8) ◽  
pp. 1420-1456
Author(s):  
Lyudmila I. PRONYAEVA ◽  
Ol'ga A. FEDOTENKOVA ◽  
Anna V. PAVLOVA
Keyword(s):  
Complex Structure ◽  
Industrial Clusters ◽  
Original Method ◽  
Structure Design ◽  
Comprehensive Approach ◽  
Industrial Complex ◽  
Cluster Approach ◽  
Agricultural Economy ◽  
Foreign Countries ◽  
Organizational Work

Subject. This article studies the processes of clustering of the agro-industrial complex of the Orel Oblast. Objectives. The article aims to develop an improved methodology for identifying regional agro-industrial clusters. Methods. For the study, we used the methods of generalization, localization, formal characterization, and the point-rating and cartographic methods. Results. The article defines modern trends in the clustering of the agricultural economy in foreign countries and Russia, and offers an original method to identify regional agro-industrial clusters. Conclusions. The developed comprehensive approach to the identification of agro-industrial clusters can help systematically arrange organizational work to create them.

scholarly journals Design and Fabrication Technology of Metal Mirrors Based on Additive Manufacturing: A Review

2021 ◽  
Vol 11 (22) ◽  
pp. 10630
Author(s):  
Kai Zhang ◽  
Hemeng Qu ◽  
Haijun Guan ◽  
Jizhen Zhang ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Complex Structure ◽  
Glass Ceramics ◽  
Fused Silica ◽  
Structure Design ◽  
Design Methods ◽  
Powder Materials ◽  
Fabrication Technology ◽  
The Common ◽  
New Generation

In recent years, much progress has been made on the development of metal mirrors based on additive manufacturing (AM). The sandwich mirror is well known for its excellent mechanical properties and challenging machining. Now, AM can be used to fabricate this complex structure and reduce the processing time and cost. In addition, with the aid of some new design methods for additive manufacturing, such as lattice, topology optimization (TO), and Voronoi, the freedom of mirror structure design is enormously improved. The common materials of mirrors include ceramics (SiC), glasses (glass ceramics, fused silica), and metals (aluminum, beryllium). Among them, the AM technology of metals is the most mature and widely used. Researchers have recently extensively developed the new-generation metal mirror to improve performance and lightweight rate. This review focuses on the following topics: (1) AM technologies and powder materials for metal mirrors, (2) recent advances in optomechanical design methods for AM metal mirrors, (3) challenges faced by AM metal mirrors in fabricating, and (4) future trends in AM metal mirrors.

Tip Leakage Behavior and Large Coherent Perturbation Analysis of an Axial-radial Combined Compressor with Outlet Distortion

2021 ◽  
Author(s):  
Li Fu ◽  
Ce Yang ◽  
Chenxing Hu ◽  
Xin Shi
Keyword(s):  
Transient Flow ◽  
Flow Instability ◽  
Complex Structure ◽  
Potential Effect ◽  
Structure Design ◽  
Mean Flow ◽  
Tip Leakage Flow ◽  
Compact Structure ◽  
Tip Leakage ◽  
Flow Unsteadiness

Abstract Increasing performance requirements and compact structure design promote the generation of axial-radial combined compressors. However, its complex structure and asymmetrical outlet boundary cause difficulty to get an in-depth comprehension of the flow unsteadiness associated with spike-stall. In this work, unsteady full-annular simulations of an axial-radial combined compressor coupled with performance experiment validations were carried out. Based on the overall understanding of outlet distortion on each component, the general feature of tip leakage flow with asymmetrical outlet boundary was extracted. The temporal and spatial development of large coherent perturbations was revealed by the decomposition and reconstruction of the transient flow data with the DMD approach. The results demonstrate that the outlet distortion can propagate reversely to the compressor inlet and the degree of distortion decreases gradually, which leads to the highest possibility for radial rotor to suffer from flow unsteadiness. In the circumferential location with distortion affected, the leakage momentum of the adjacent blade LE is enhanced by the secondary leakage, inducing the expansion of TLV and causing flow instability. Besides organized perturbation structures related to mean flow and BPF, two large low-frequency stall perturbations approximately one-third and three-fourth RF was captured by the DMD method, which is caused by volute potential effect and stator/rotor interference, respectively. The former occurs in the radial rotor and decays during its propagation, while the latter always exists owing to the multiple rotor/stator or stator/rotor interference in the axial-radial combined compressor.

Mesh Mapping of Large Deployable Reflector in Mechanical - Electromagnetic Analyses

2012 ◽  
Vol 460 ◽  
pp. 43-47 ◽  
Author(s):  
Mei Chen ◽  
Fei Zheng ◽  
Na Li
Keyword(s):  
Complex Structure ◽  
Mapping Method ◽  
Structure Design ◽  
Space Applications ◽  
Lightweight Structures ◽  
Electromagnetic Model ◽  
Mechanical Deformations ◽  
The Relationship ◽  
Deployable Reflector ◽  
Mesh Mapping

Ultra lightweight large deployable reflector antenna is gradually used nowadays in space applications. Both lightweight structures and materials are used. The relationship between the structure design and the electromagnetic performances is much tighter than other ground electric devices. This paper presents a mesh mapping method of large deployable reflector in mechanical - electromagnetic analyses. By using this method, the mechanical deformations can be precisely transformed on the electromagnetic model. It can be used to understand the relationship between the mechanical deformations and the electromagnetic performances on such a huge, complex structure.

scholarly journals FACTOR EQUIVALENCE OF GALOIS MODULES AND REGULATOR CONSTANTS

2014 ◽  
Vol 10 (01) ◽  
pp. 1-12
Author(s):  
ALEX BARTEL
Keyword(s):  
Number Fields ◽  
The Other ◽  
Module Structure ◽  
Integral Group ◽  
Galois Module ◽  
Group Representations ◽  
Galois Modules ◽  
Rings Of Integers ◽  
The One ◽  
Module Structures

We compare two approaches to the study of Galois module structures: on the one hand, factor equivalence, a technique that has been used by Fröhlich and others to investigate the Galois module structure of rings of integers of number fields and of their unit groups, and on the other hand, regulator constants, a set of invariants attached to integral group representations by Dokchitser and Dokchitser, and used by the author, among others, to study Galois module structures. We show that the two approaches are in fact closely related, and interpret results arising from these two approaches in terms of each other. We then use this comparison to derive a factorizability result on higher K-groups of rings of integers, which is a direct analogue of a theorem of de Smit on S-units.

Research Progress of Extended-Reach Well Antifriction Technology

2013 ◽  
Vol 868 ◽  
pp. 638-644
Author(s):  
Hui Zeng Zhang ◽  
Zhi Chuan Guan ◽  
Yu Qiang Xu ◽  
Qian Deng Li ◽  
Ling Chao Xuan
Keyword(s):  
Large Deviation ◽  
Complex Structure ◽  
Drill Pipe ◽  
Drill String ◽  
Field Application ◽  
Structure Design ◽  
Research Progress ◽  
Working Principle ◽  
The Common ◽  
Extended Reach Well

There is a remarkable friction between drill string and borehole in extended-reach wells and horizontal wells due to large deviation angle, contact between drill string and borehole, non-rotation of drill string. The large friction and torque will induce blocked bit weight, low ROP, constrained drill string extension. This article summarizes the common used antifriction methods and tools in extended-reach wells, focusing on Non-Rotation Drill Pipe Protector (NRDPP), roller antifriction tools and vibration antifriction tools. The working principle, structure design, performance and field application of which are introduced. With the increasing numbering of complex structure wells which include extended-reach well and horizontal well, antifriction technology has broad prospects for development.

The Ribosome: A biochemist's mechano set

1985 ◽  
Vol 63 (5) ◽  
pp. 313-318 ◽  
Author(s):  
Ross N. Nazar
Keyword(s):  
Protein Synthesis ◽  
Complex Structure ◽  
Higher Order ◽  
Order Structure ◽  
Ribosomal Rnas ◽  
Experimental Approaches ◽  
Universal Structure ◽  
Order Structures

A ribosome, the cellular site for protein synthesis, is a very complex organelle composed of a myriad of macromolecular substructures. As models for this complex structure, we have been examining the structures and interactions of eukaryotic 5S and 5.8S rRNAs using adaptations of rapid RNA gel sequencing techniques. Estimates for their higher order structures have been proposed or evaluated, sites of interaction with other ribosomal components have been delineated, and the topography of these RNAs within the intact ribosome or 60S subunit have been examined. The results indicate that a universal structure for the ribosomal RNAs may only be present within the ribosome, that these molecules are probably present, at least in part, within the ribosomal interface, and that the bases for interactions with other ribosomal components are strongly dependent on their higher order structure. The experimental approaches which underlie these studies are considered in this review and the significance of the results with respect to the function and evolution of the ribosome are briefly discussed.

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