Search

We consider approximate, exact, and numerical solutions to the cylindrical Korteweg-de Vries equation. We show that there are different types of solitary waves and obtain the dependence of their parameters on distance. Then, we study the interaction of solitary waves of different types., Comment: 18 pages, 9 figures

Compared with the lever-type amplifier, the rhombus-type amplifier has attracted more attention by virtue of large displacement amplification ratio, compact structure, and linear output displacement. In this paper, a novel electromagnetic force balance sensor (EFBS) based on the rhombus-type amplifier is presented to measure the mass with high precision. First, the structure and operating principle of the EFBS are described, and the requirements for the design and manufacture of the amplifier are put forward. Then, the analytical models of the two-stage rhombus-type amplifier are given out, and two guiding mechanisms are analyzed and modeled. Furthermore, the validity of the established model is verified by finite element analysis (FEA). Thanks to the theoretical guidance, an electromagnetic force balance sensor based on the two-stage rhombus-type amplifier and double parallelogram flexure mechanism is designed and tested. The experimental results demonstrate that the developed EFBS can measure the mass of the objects with high precision, and also verifies the correctness of the analytical model. This provides a new concept for the structural design of the EFBS.

All-organic polyimide (PI)/poly(vinylidene fluoride) (PVDF) composite materials with high dielectric constant and low dielectric loss were fabricated via solution blending followed by the chemical imidization of polyamic acid (PAA, precursor of PI) at a low temperature. The dielectric and thermal properties of the PI/PVDF composites were investigated. Results indicated that the dielectric properties of the composites were significantly increased due to the incorporation of PVDF, and the composites exhibited excellent thermal stability. The dielectric constant of the composites was sharply increased to 7.745 at 1 kHz, which was approximately 2.1 times higher than that of pure PI. The dielectric loss was only 0.0898 when PVDF content was as high as 50 wt.%. Moreover, the dependence of the dielectric constant and dielectric loss on frequency was studied. Within the testing frequency range of 100 Hz–1 MHz, the dielectric constant of the composites slightly decreased and the dielectric loss was less than 0.12. The results demonstrated that the PI/PVDF composites were promising dielectric materials for modern electronic applications.