Civil Aviation University of China

About: Civil Aviation University of China is a education organization based out in Tianjin, China. It is known for research contribution in the topics: Air traffic control & Civil aviation. The organization has 5647 authors who have published 4559 publications receiving 29825 citations. The organization is also known as: Zhōngguó Mínháng Dàxué.

Determination of optical coefficients of biological tissue from a single integrating-sphere

Abstract: The detection of interactions between light and tissue can be used to characterize the optical properties of the tissue. The development is described of a method that determines optical coefficients of biological tissue from a single optical reflectance spectrum measured with an integrating-sphere. The experimental system incorporated a DH-2000 deuterium tungsten halogen light source, a USB4000-VIS-NIR miniature fiber optic spectrometer and an integrating-sphere. Fat emulsion and ink were used to mimic the scattering and absorbing properties of tissue in the tested sample. The measured optical reflectance spectrums with different scattering and absorbing properties were used to train a back-propagation neural network (BPNN). Then the neural network (BPNN) was used to determine the optical coefficients of biological tissue from a single optical reflectance spectrum measured with an integrating-sphere. Tests on tissue-simulation phantoms showed the relative errors of this technique to be 7% for the reduced ...

Accuracy analysis and synthesis of asymmetric parallel mechanism based on Sobol-QMC:

Abstract: Aiming at the aircraft composite skin grinding, a new three degree-of-freedom (DOF) parallel mechanism with asymmetrical structure (TAM) is proposed to replace manual grinding. The TAM is achieved ...

Growth mechanism and characterization of ZnO nano-tubes synthesized using the hydrothermal-etching method

Abstract: ZnO nano-tubes (ZNTs) have been successfully synthesized via a simple hydrothermal-etching method, and characterized by X-ray diffraction, field emission scanning electron microscopy and room temperature photoluminescence measurement. The as-synthesized ZNTs have a diameter of 500 nm, wall thickness of 20–30 nm, and length of 5 µm. Intensity of the plane (0002) diffraction peak, compared with that of plane (10\( \bar 1 \)0) of ZNTs, is obviously lower than that of ZnO nano-rods. This phenomenon can be caused by the smaller cross section of plane (0002) of the nano-tubes compared with that of other morphologies. On basis of the morphological analysis, the formation process of nano-tubes can be proposed in two stages: hydrothermal growth and reaction etching process.

An Empirical Study on Low-Carbon: Human Resources Performance Evaluation.

Abstract: Low-carbon logistics meets the requirements of a low-carbon economy and is the most effective operating model for logistic development to achieve sustainability by coping with severe energy consumption and global warming. Low-carbon logistics aims to reduce carbon intensity rather than simply reduce energy consumption and carbon emissions. Human resources are an important part of the great competition in the logistics market and significantly affect the operations of enterprises. Performance evaluations of human resources are particularly important for low-carbon logistics enterprises with scarce talents. Such evaluations in these enterprises are of great significance for their strategic development. This study constructed a human resource performance evaluation system to assess non-managerial employees' low-carbon job capacity, job performance, and job attitude in the low-carbon logistics sector. The case study results revealed that the investigated company enjoyed initial success after having promoted low-carbon concepts and values to its non-managerial employees, and the success was demonstrated by excellent performance in its employees' job attitude and knowledge. This study adopts the AHP method to reasonably determine an indicator system of performance evaluation and its weight to avoid certain human-caused bias. This study not only fills the gap in the related literature, but can also be applied to industrial practice.

Effect of staggered holes with multi-site damage on fatigue performance based on tests, DIC technique and numerical calculations

Abstract: The fatigue performance was investigated numerically and experimentally of 2024-T3 Al-clad sheet with staggered hole arrangement and multi-sites damage (MSD), which is mainly used in aging aircraft fuselage skin. Firstly, the influences of row spacing, column spacing and inter-crack direction on fatigue life were studied. Then, the strain nephogram and crack path were analyzed with the assistance of digital image correlation (DIC) technique. Finally, a numerical solution for the specimens with staggered holes and MSD was developed based on the combination of ABAQUS and Paris formula. The results show that with the increase of row spacing, the fatigue life of MSD specimens with fixed column spacing increases first and then decreases. In the case of fixed row spacing, the fatigue life of specimens increases with the increase of column spacing. The arrangement parameter α is introduced to reveal the crack propagation form. Meanwhile, the common form of fracture is through the upper row of hole. In addition, the distribution of rivet holes has an effect on the initiation life of fatigue cracks in the structure with MSD, especially the row spacing. The numerical solution could provide a conservative prediction of fatigue lives, and the predicted error is less than 5% for cases of HH-2g24.