Rejection of Direct Blast Interference Based on Signal Phase-Matching Array Processing

In bistaic acoustic testing, there will be strong direct blast interference. An algorithm based on signal phase-matching array processing that rejects direct blast interference in bistatic acoustic testing has been studied, through which the object scattering signal is accurately extracted. Characteristics of bistatic acoustic testing and signal phase matching processing principle are fully integrated in this algorithm. Firstly, the direct blast interference is calculated from the receiving signal based on three subarrays signal phase matching processing. Secondly, the direct blast is rejected by subtraction from the receiving signal. In this way the limitations of the high signal to noise ratio that signal phase matching processing required for direct calculating the object scattering signal can be avoided. Simulation and sea trial results show that, when the ratio of signal to interference is greater than -20 dB, this algorithm of direct blast interference rejection based phase matching signal processing can accurately extract the object scattering signal.

Nanodot array deposition via single shot laser interference pattern using laser-induced forward transfer

Laser-induced forward transfer(LIFT)is a direct-writing technique capable of depositing a single dot smaller than the laser wavelength at small shot energy through the laser-induced dot transfer(LIDT)technique.To deposit a single nanodot in a single shot of laser irradiation,a liquid nanodrop is transferred from donor to receiver and finally solidified via a solid–liquid–solid(SLS)process.In conventional LIDT experiments,multi-shots with step scanning have been used to form array structures.However,interference laser processing can achieve an arrayed process and generate a periodic structure in a single shot.In this study,a femtosecond laser interference pattern was first applied to LIDT,and an array of nanodots was successfully deposited in a single shot,producing the following unit structures:a single dot,adjoining dots,and stacking dots.The diameter of the smallest nanodot was 355 nm,and the narrowest gap between two adjoining nanodots was 17.2 nm.The LIDT technique produces high-purity,catalyst-free that do not require post-cleaning or alignment processes.Given these significant advantages,LIDT can expand the usability of nanodots in a wide range of fields.

Photodetachment of H^- near a hard wall with arbitrary laser polarization direction

The photodetachment of H-near a hard wall is investigated with linear polarized laser light travelling in arbitrary direction θL with respect to the z axis. An analytical formula for the total cross section is derived using semi-classical closed orbit theory, which consists of two terms, i.e., the smooth background term and the oscillatory term with an extra factor 2(θL). This factor controls oscillations in the total photodetachment cross section. The amplitude of oscillation is maximum at θL = 0 when the laser polarization direction is perpendicular to the wall and it approaches zero at θL = π /2when the laser polarization direction is parallel to the wall. It is also observed that the total cross section depends on the source–wall distance and it reduces to a free space case when the wall is at infinite distance from the source.

A combined signal processing approach against coherent interference with pressure and particle velocity

Comparing with traditional underwater acoustic system which only utilizes pressure information, combine sensor system processes pressure together with particle velocity information of sound field. More information certainly brings nicer processing result. By using spatial directional information collected by combine sensor, the Coherent Interference Energy Suppress (CIES) technology, which can effectively suppress coherent interference and detect linear spectrum signal and wide-band continuous-spectrum signal as well, is presented. Current research has shown favorite result, and further research is going on.

Does Government’s Waiving of Court Fees Interfere in the Judicial Process?

It isn’t often that officialdom helps fi-nance a businessperson’s court fees in a lawsuit where it is the accused.But that is exactly what happened in Chenghua District Chengdu,capital of Sichuan Province,where the local government recently took the sur-prising action of assisting plaintiff and auto parts manufacturer Gu Kui in fighting a court battle to sue itself.