Absorbing properties of three dimensional honeycomb-structured absorbing materials

2012 ◽  
Author(s):  
Lujun Wu ◽  
Qun Wang ◽  
Zhanghong Tang
Keyword(s):  
Three Dimensional ◽  
Absorbing Materials

scholarly journals Evaluating the Tire/Pavement Noise and Surface Texture of Low-Noise Micro-Surface Using 3D Digital Image Technology

2021 ◽  
Vol 8 ◽  
Author(s):  
Wang Chen ◽  
Mulian Zheng ◽  
Haiyang Wang
Keyword(s):  
Noise Reduction ◽  
Digital Image ◽  
Surface Texture ◽  
Three Dimensional ◽  
Low Noise ◽  
Road Noise ◽  
Texture Model ◽  
Promising Tool ◽  
Absorbing Materials ◽  
Reduction Effect

As a common preventive maintenance technique for asphalt pavement, micro-surface (MS) has the advantages of waterproofing and crack sealing. However, issues such as the fact that the conventional MS generates large noise and the evaluation of the indexes of tire-road noise are relatively less studied. The traditional surface texture index cannot reveal the range and distribution of pavement surface texture, thus hindering research of low-noise MS. To study the mechanism of tire-road noise generated by MS, and propose the tire-road noise and surface texture indicators for MS. In this study, the mechanism of five low-noise MS was systematically analyzed and compared through surface texture and noise tests. Then, a three-dimensional digital texture model (3D-DTM) of MS surface texture was constructed using a series of digital image processing techniques, including grayscale identification, binary conversion, and noise reduction. The results show that optimizing the gradation, adding sound-absorbing materials, and improving the workability of construction can improve the noise reduction performance of MS, it is worth mentioning that the MS prepared with sound-absorbing materials and low-noise gradation has the greatest noise reduction effect, with a maximum reduction of 6.3 dB(A). In addition, it was also found that the 3D-DTM can well reflect the surface texture characteristics of MS. The probability of convex peak distribution (PCD) and the proportion of convex peak area (PCA) with peak heights greater than 0.25 mm (Kh ≥ 0.25), which are extracted from the 3D-DTM, can well reflect the surface texture, tire-road noise, respectively. The results show that the 3D-DTM is a promising tool to optimize the design of low-noise MS.

Three-dimensional perovskite modulated by two-dimensional homologue as light-absorbing materials for efficient solar cells

2019 ◽  
Vol 74 ◽  
pp. 126-134 ◽  
Author(s):  
Can Gao ◽  
Ziyang Hu ◽  
Cheng Yang ◽  
Haoyuan Xu ◽  
Yanyan Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Absorbing Materials

Morphology-dependent electromagnetic wave absorbing properties of iron-based absorbers: one-dimensional, two-dimensional, and three-dimensional classification

2019 ◽  
Vol 87 (2) ◽  
pp. 20901 ◽  
Author(s):  
Zehao Zhao ◽  
Zirui Jia ◽  
Hongjing Wu ◽  
Zhenguo Gao ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Interference ◽  
High Performance ◽  
Low Cost ◽  
Impedance Matching ◽  
Three Dimensional ◽  
Microwave Absorbing Materials ◽  
Dimensional Classification ◽  
Absorbing Materials ◽  
Microwave Absorbing

Owing to the fast development of wireless techniques at the high-frequency range, the electromagnetic interference problem has been of increasing significance and attracting global attention. It is urgent to develop efficient microwave absorbing materials to attenuate the harmful electromagnetic wave. Iron and Fe-based composites are advantageous in the low-cost and attractive magnetic properties, so they have been widely studied in microwave absorption. This review focuses on the latest advances in nanostructured Fe-based materials including nanostructured iron, Fe/C (carbon nanotubes, nanofibers, nanocapsules, etc.), Fe/semiconductor (TiO2, MnO2, ZnO, SiO2, MoS2, etc.), Fe/polymer (polyaniline and polypyrrole), FeCo alloy, etc. However, most of these Fe-based materials suffer from the poor impedance matching and oxidation, which seriously impede their implementation as high-performance microwave absorbing materials. In this review, the main synthesis and modification methods, as well as the practical performance of Fe-based microwave absorbing materials are discussed. Moreover, challenges and perspectives of Fe-based composites for further development in microwave absorbing materials are proposed.

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

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