Enhancement of Ultrasonic Transducer Bandwidth by Acoustic Impedance Gradient Matching Layer.

High-performance broadband ultrasound transducers provide superior imaging quality in biomedical ultrasound imaging. However, a matching design that perfectly transmits the acoustic energy between the active piezoelectric element and the target medium over the operating spectrum is still lacking. In this work, an anisotropic gradient acoustic impedance composite material as the matching layer of an ultrasonic transducer was designed and fabricated; it is a non-uniform material with the continuous decline of acoustic impedance along the direction of ultrasonic propagation in a sub-wavelength range.

Increasing Performances of 1-3 Piezocomposite Ultrasonic Transducer by Alternating Current Poling Method.

Ultrasonic transducers are the basic core component of diagnostic imaging devices, wherein the piezoelectric materials are the active element of transducers. Recent studies showed that the alternating current poling (ACP) method could develop the properties of piezocomposites, which had great potential to improve transducer performance. Herein, transducers ( = 3 MHz) made of DCP and ACP 1-3 piezocomposites (prepared by PZT-5H ceramics and PMN-PT single crystals) were fabricated.

Phase-field simulation on the interaction of oxygen vacancies with charged and neutral domain walls in hexagonal YMnO.

A three-dimensional model of the interaction between the charged or neutral domain walls and oxygen vacancies in the hexagonal manganite YMnOwas proposed, and simulated using Landau-Ginzburg-Devonshire (LGD) theory, dynamic diffusion equation and Maxwell's equation. The calculation proves that stiffness anisotropic factors can adjust the domain wall state and ultimately affect the distribution of oxygen vacancies. The head-to-head domain wall corresponds to low oxygen vacancy density, and the tail-to-tail domain wall corresponds to high oxygen vacancy density.

Enhancing the Temperature Stability of 0.42PNN-0.21PZ-0.37PT Ceramics through Texture Engineering.

Although the MPB composition 0.42PNN-0.21PZ-0.

Highly sensitive optical ratiometric thermometry by exciting Eu/Tb's unusual absorption lines.

A guideline for designing sensitive thermometry is proposed. It reveals that using two emission bands that possess the opposite change tendencies against temperature makes it easier to achieve a larger relative sensitivity. Based on the guidelines, a highly sensitive strategy for optical thermal detection that depends on the Tb3+-to-Eu3+ emission ratio is designed by exciting Eu3+/Tb3+'s unusual absorption lines.

Green synthesis of benzonitrile using ionic liquid with multiple roles as the recycling agent.

Preparation of benzonitrile from benzaldehyde and hydroxylamine hydrochloride is one of the most advantageous approaches. Nevertheless, it suffers from various constraints such as longer reaction time, corrosion and recovery of hydrochloric acid, the use of metal salt catalysts and their separation. For these reasons, a novel green benzonitrile synthetic route was proposed with ionic liquid as the recycling agent in this study.

Electromechanical properties of orthorhombic 0.24Pb(InNb)O-0.43Pb(MgNb)O-0.33PbTiO single-domain crystal.

Single-domain structure with orthorhombic symmetry has been achieved in morphotropic phase boundary composition 0.24Pb(InNb)O -0.43Pb(MgNb)O-0.

Optimization of electrooptic and pieozoelectric coupling effects in tetragonal relaxor-PT ferroelectric single crystals.

The electrooptic and piezoelectric coupling effects in tetragonal relaxor-based ferroelectric 0.62Pb(MgNb)O-0.38PbTiO (PMN-0.

A novel hydroxylamine ionic liquid salt resulting from the stabilization of NH2OH by a SO3H-functionalized ionic liquid.

A SO3H-functionalized ionic liquid was used as an alternative to conventional inorganic acids in hydroxylamine stabilization, leading to the formation of a novel hydroxylamine ionic liquid salt that exhibits improved thermal stability and reactivity in the one-step, solvent-free synthesis of caprolactam in comparison with hydroxylamine hydrochloride and hydroxylamine sulfate.

Landfill leachate production, quality and recirculation treatment in northeast China.

Landfill leachate recirculation treatment process is a promising and economic way in northeast China due to the distinct season variation. In order to study the impact of recirculation on leachate production and its quality, two simulated sanitary landfill reactors, one with leachate recirculation and the other without, were placed outdoor in Harbin. The two-year experimental results indicated that leachate production was reduced by 86% with leachate recirculation and less or no facility for leachate treatment required.

[Prediction of landfill leachate production in cold area conversion].

Leachate production is evidently discontinuous in the chilly northeast areas because of the distinct 4-seasons conversion and long frozen time. In order to investigate into the leachate production variability and the impact of leachate recirculation on sanitary landfill, two simulated landfill reactors were constructed outdoors, which were filled with the same municipal solid waste. One reactor was provided with leachate recirculation and the other without as a control.