New matrix method for response analysis of circumferentially stiffened non-circular cylindrical shells under harmonic pressure

Based on the governing equation of vibration of a kind of cylindrical shells written in a matrix differential equation of the first order, a new matrix method is presented for steady-state vibration analysis of a noncircular cylindrical shell simply sup- ported at two ends and circumferentially stiffened by rings under harmonic pressure. Its difference from the existing works by Yamada and Irie is that the matrix differential equation is solved by using the extended homogeneous capacity precision integration＇ approach other than the Runge-Kutta-Gill integration method. The transfer matrix can easily be determined by a high precision integration scheme. In addition, besides the normal interacting forces, which were commonly adopted by researchers earlier, the tangential interacting forces between the cylindrical shell and the rings are considered at the same time by means of the Dirac-δ function. The effects of the exciting frequencies on displacements and stresses responses have been investigated. Numerical results show that the proposed method is more efficient than the aforementioned method.

Monolithic homogeneous integrated miniaturized triboelectric nanogenerator with an inner air cavity for energy harvesting

To realize the high-efficiency acquisition of environmental mechanical energy,traditional triboelectric nanogenerators(TENGs)based on contact-separation consist of two separate triboelectric layers.Their large contact-separation gap increases the overall volume of the device,making it difficult to realize miniaturization and flexibility.This work,therefore,presents a fully enclosed all-in-one-shaped flexible TENG(FEAST)with an air cavity using rubber mixing and high-temperature vulcanization.The air pressure inside the enclosed air cavity facilitates effective contact-separation of the FEAST.The homogeneous integration between the triboelectric layer and the electrode layer enhances structural firmness without using extra spacer materials.The developed FEAST presents excellent mechanical durability even after 10000 cycles.By increasing the active contact area between the triboelectric materials,a maximum peak-peak output voltage,current,and power density of 130 V,1.1μA,and277 m W/m^(2),respectively,were obtained with an effective stress area of 1 cm2.Moreover,the fully enclosed structure ensures that the output performance is not affected by the external environment.The FEAST was fixed onto the sole of a shoe to demonstrate its applicability in harvesting mechanical energy from human motions.Overall,the developed method provides a simple approach for optimizing the structure of TENGs and is compatible with large-scale manufacturing.

Compactness of the commutators of homogeneous singular integral operators

Let TΩ be the singular integral operator with kernel Ω（x）/｜x｜n where is homogeneous of degree zero, integrable and has mean value zero on the unit sphere Sn-1. In this paper, by Fourier transform estimates, Littlewood-Paley theory and approximation, the authors prove that if Ω∈（lnL）2 （Sn- 1）, then the commutator generated by TΩ and CMO（Rn） function, and the corresponding discrete maximal operator, are compact on LP（Rn, ｜s｜γp） for p∈ （1, ∞） and γp ∈ （-1, p-l）

Geometry and Hardy spaces on spaces of homogeneous type in the sense of Coifman and Weiss

It is known that the space of homogeneous type introduced by Coifman and Weiss(1971) provides a very natural setting for establishing a theory of Hardy spaces. This paper concentrates on how the geometrical conditions of the space of homogeneous type play a crucial role in building a theory of Hardy spaces via the Littlewood-Paley functions.

On-chip optical interconnect using visible light

We propose and fabricate a monolithic optical interconnect on a GaN-on-silicon platform using a wafer-level technique. Because the InGaN/GaN mukiple-quantum-well diodes （MQWDs） can achieve light emission and detection simultaneously, the emitter and collector sharing identical MQW structure are produced using the same process. Suspended waveguides interconnect the emitter with the collector to form in-plane light coupling. Monolithic optical interconnect chip integrates the emitter, waveguide, base, and collector into a multi-component system with a common base. Output states superposition and 1 × 2 in-piane light communication are experimentally demonstrated. The proposed monolithic optical interconnect opens a promising way toward the diverse applications from in-plane visible light communication to light-induced imaging, and optical sensing. artificial synaptic devices, intelligent display, on-chip

Singular and fractional integral operators on preduals of Campanato spaces with variable growth condition

We investigate the boundedness of singular and fractional integral operators on generalized Hardy spaces defined on spaces of homogeneous type, which are preduals of Campanato spaces with variable growth condition. To do this we introduce molecules with variable growth condition. Our results are new even for R^n case.