Collaborative non-local topology optimization of gradient acoustic metasurfaces for broadband extreme reflection modulation.

To control the complex energy flow between neighboring microstructures for realizing the extreme acoustic functionality using a large-scale non-local metamaterial, here this paper shows that a collaborative non-local topology-optimization methodology is developed to construct gradient acoustic metasurfaces with smooth boundaries for the broadband large-angle reflection. An inverse-designed non-local acoustic metasurface is numerically and experimentally validated to support the large reflection angles within the low-frequency broadband range while maintaining high efficiency greater than 98.9%.

Adjustable Phase-Amplitude-Phase Acoustic Metasurface for the Implementation of Arbitrary Impedance Matrices.

Impedance metasurfaces enable accurate regulation of acoustic fields. However, they can hardly supply a flexible response as such perfect operation is accompanied by stringent requirements on the design of unit cells. Actually, an arbitrary lossless and passive target impedance matrix requires the tuning of 3 independent real parameters.

Dynamic Acoustic Beamshaping with Coupling-Immune Moiré Metasurfaces.

Moiré effects arising from mutually twisted metasurfaces have showcased remarkable wave manipulation capabilities, unveiling tantalizing emerging phenomena such as acoustic moiré flat bands and topological phase transitions. However, the pursuit of strong near-field coupling in layers has necessitated acoustic moiré metasurfaces to be tightly stacked at narrow distances in the subwavelength range. Here, moiré effects beyond near-field interlayer coupling in acoustics are reported and the concept of coupling-immune moiré metasurfaces is proposed.

[Risk factors for delayed bleeding after intestinal polypectomy in children].

Objectives: To investigate the clinical characteristics and risk factors of delayed bleeding after intestinal polypectomy in children, and to provide a theoretical basis for clinical surgical intervention of intestinal polyps.

Methods: A retrospective analysis was conducted on the clinical data of 2 456 children with intestinal polyps who underwent endoscopic high-frequency electrocoagulation loop resection in the Endoscopy Center of Children's Hospital Affiliated to Zhengzhou University from January 2014 to December 2021. According to the presence or absence of delayed bleeding after surgery, they were divided into bleeding group with 79 children and non-bleeding group with 2 377 children.

Hybrid Metasurfaces for Perfect Transmission and Customized Manipulation of Sound Across Water-Air Interface.

Extreme impedance mismatch causes sound insulation at water-air interfaces, limiting numerous cross-media applications such as ocean-air wireless acoustic communication. Although quarter-wave impedance transformers can improve transmission, they are not readily available for acoustics and are restricted by the fixed phase shift at full transmission. Here, this limitation is broken through impedance-matched hybrid metasurfaces assisted by topology optimization.

Achromatic metasurfaces by dispersion customization for ultra-broadband acoustic beam engineering.

Metasurfaces, the ultra-thin media with extraordinary wavefront modulation ability, have shown great promise for many potential applications. However, most of the existing metasurfaces are limited by narrow-band and strong dispersive modulation, which complicates their real-world applications and, therefore require strict customized dispersion. To address this issue, we report a general methodology for generating ultra-broadband achromatic metasurfaces with prescribed ultra-broadband achromatic properties in a bottom-up inverse-design paradigm.

Nano-gold micelles loaded Dox and Elacridar for reversing drug resistance of breast cancer.

The aim of this study was to provide a new effective carrier for rescuing the sensitivity of drug-resistant in breast cancer cells. Nano-gold micelles loaded with Dox and Elacridar (FP-ssD@A-E) were chemically synthesised. With the increase in the amount of Dox and Elacridar, the encapsulation rate of FP-ssD@A-E gradually increased, and the drug loading rate gradually decreased.

A Nonlinear Magnetoelastic Energy Model and Its Application in Domain Wall Velocity Prediction.

In this letter, we propose a nonlinear Magnetoelastic Energy (ME) with a material parameter related to electron interactions. An attenuating term is contained in the formula of the proposed nonlinear ME, which can predict the variation in the anisotropic magneto-crystalline constants induced by external stress more accurately than the classical linear ME. The domain wall velocity under stress and magnetic field can be predicted accurately based on the nonlinear ME.

Photoactive nanomaterials enabled integrated photo-rechargeable batteries.

The research interest in energy storage systems ( batteries and capacitors) has been increasing over the last years. The rising need for electricity storage and overcoming the intermittent nature of renewable energy sources have been potent drivers of this increase. Solar energy is the most abundant renewable energy source.

Broadband square cloak in elastic wave metamaterial plate with active control.

Cloaking invisibility is a novel technique that prevents the object from being detected in the background field. The development of new artificial materials and structures promotes the emergence of new achievements in cloaking research. In this work, a broadband square cloaking configuration of elastic wave metamaterial plate is designed and fabricated by the external active control system.

Electro-mechanical coupling diode of elastic wave in nonlinear piezoelectric metamaterials.

In this investigation, the bandgaps and nonreciprocal transmission of the nonlinear piezoelectric phononic crystal and elastic wave metamaterial are studied. Analytical solutions for the wave motion equations with the electro-mechanical coupling are obtained. According to the continuous conditions, the stop bands and transmission coefficients of both fundamental wave and second harmonic are derived by the stiffness matrix method.

Active control on topological immunity of elastic wave metamaterials.

The topology concept in the condensed physics and acoustics is introduced into the elastic wave metamaterial plate, which can show the topological property of the flexural wave. The elastic wave metamaterial plate consists of the hexagonal array which is connected by the piezoelectric shunting circuits. The Dirac point is found by adjusting the size of the unit cell and numerical simulations are illustrated to show the topological immunity.

Comparison of Bioelectrical Impedance Analysis and Dual Energy X-ray Absorptiometry for Total and Segmental Bone Mineral Content with a Three-Compartment Model.

Modern bioelectrical impedance analysis (BIA) provides a wide range of body composition estimates such as fat mass (FM), lean body mass (LBM), and body water, using specific algorithms. Assuming that the fat free mass (FFM) and LBM can be accurately estimated by the 8-electrode BIA analyzer (BIA; InBody230, Biospace), the bone mineral content (BMC) may be calculated by subtracting the LBM from the FFM estimates based on the three-compartment (3C) model. In this cross-sectional study, 239 healthy Taiwanese adults (106 male and 133 female) aged 20-45 years were recruited for BIA and dual-energy X-ray absorptiometry (DXA) measurements of the whole body and body segments, with DXA as the reference.

[Application of quality constant method in grade evaluation of Aurantii Fructus Immaturus pieces].

The grade classification of Chinese herbal medicines and their decoction pieces has always been a hot issue in the industry. In the trading history of Chinese herbal medicine,buyers and sellers often determine the price according to quality,so the naturally formed specifications and grades are changing with the change of technology and the increasing demand of the public for medical care.The planting,processing and circulation methods of Chinese medicinal materials have also changed greatly.

Does a spinal implant alter dual energy X-ray absorptiometry body composition measurements?

Background: Most manufacturer manuals do not verify the use of dual energy X-ray absorptiometry for body composition analysis in subjects with a metal implant. This study aimed to quantify the effects of a spinal implant on body composition, and to determine whether unadjusted lean mass estimates are valid for patients with a spinal implant.

Methods: A total of 30 healthy subjects were recruited.

Solitary waves in a granular chain of elastic spheres: Multiple solitary solutions and their stabilities.

A granular chain of elastic spheres via Hertzian contact incorporates a classical nonlinear force model describing dynamical elastic solitary wave propagation. In this paper, the multiple solitary waves and their dynamic behaviors and stability in such a system are considered. An approximate KdV equation with the standard form is derived under the long-wavelength approximation and small deformation.