Dual-circularly polarized flat-top-beam transmitarray antenna with flexible energy allocations.

To fulfill the continuously developing requirements of satellite communications and radar detection, this paper demonstrates a theoretical and experimental investigation of dual-circularly polarized (CP) transmitarray antennas (TAs) capable of generating spin-decoupled flat-top beams with customized gain differences. The constituent element for the transmitarray is a high-efficiency receiver-transmitter structure composed of a CP receiving antenna and a polarization-adjustable transmitting antenna. By rotating these two antennas jointly and modifying dimensions of transmitting patch, independent phase shifts and flexible energy allocations can be imparted to dual-CP transmitting waves, respectively.

Gradient Surface Gallium-Doped Hematite Photoelectrode for Enhanced Photoelectrochemical Water Oxidation.

Hematite is a promising material for photoelectrochemical (PEC) water oxidation, but its photocurrent is limited by bulk charge recombination and poor oxidation kinetics. In this study, we report a high-performance FeO photoanode achieved through gradient surface gallium doping, utilizing a GaO overlayer on FeOOH precursors via atomic layer deposition (ALD) and co-annealing for Ga diffusion. The Ga-doped layer passivates surface states and modifies the band structure, creating a built-in electric field that enhances the charge separation efficiency.

Design of a low-profile bi-directional radiated Fabry-Perot cavity antenna with independent forward and backward radiation based on metasurface technique.

This paper introduces a novel Fabry-Perot cavity (FPC) antenna design based on metasurface technique to achieve bi-directional radiation with independent forward and backward beam control capability and a low-profile configuration. Two pieces of partially reflective metasurface (PRMS) based on receiver-transmitter architecture with independent control of transmission and reflection phases are designed to serve as the upper and lower layers of the FPC antenna, respectively. By manipulating the transmission phase distribution of the two pieces of PRMS, designable independent multi-beam bi-directional radiation patterns can be achieved.

Semitransparent CuO Films Based on CuO Back Layer for Photoelectrochemical Water Splitting and Photovoltaic Applications.

Cuprous oxide (CuO) as an intrinsic p-type semiconductor is promising for solar energy conversion. The major challenge in fabricating CuO lies in achieving both high transparency and high performance in a tandem device. The CuO photocathodes often employ gold as the back contact layer.

Photoelectrochemical Ethylene Glycol Oxidization Coupled with Hydrogen Generation Using Metal Oxide Photoelectrodes.

Photoelectrochemical (PEC) water splitting represents a promising approach for harnessing solar energy and transforming it into storable hydrogen. However, the complicated 4-electron transfer process of water oxidation reaction imposes kinetic limitations on the overall efficiency. Herein, we proposed a strategy by substituting water oxidation with the oxidation of ethylene glycol (EG), which is a hydrolysis byproduct of polyethylene terephthalate (PET) plastic waste.

High carrier mobility along the [111] orientation in CuO photoelectrodes.

Solar fuels offer a promising approach to provide sustainable fuels by harnessing sunlight. Following a decade of advancement, CuO photocathodes are capable of delivering a performance comparable to that of photoelectrodes with established photovoltaic materials. However, considerable bulk charge carrier recombination that is poorly understood still limits further advances in performance.

Improving the photovoltage of CuO photocathodes with dual buffer layers.

Cuprous oxide (CuO) is a promising oxide material for photoelectrochemical water splitting (PEC), and increasing its photovoltage is the key to creating efficient overall PEC water-splitting devices. Previous reports are mostly focused on optimizing the energy band alignment between CuO and the n-type buffer layer to improve the photovoltage of CuO photocathodes. However, the band alignment between the n-type buffer layer and the protective layer is often ignored.

Full-space dual-helicity decoupled metasurface for a high-efficiency multi-folded reflective antenna.

The independent tailoring of electromagnetic waves with different circular-polarized (CP) wavefront in both reflection and transmission channels is of broad scientific and technical interest, offering ultimate degrees of freedom in designing advanced devices with the merits of functionality integration and spatial exploitation. However, most metasurfaces only provide dependent wavefront control of dual-helicity in a single channel, restricting their applications to limited practical scenarios. Herein, we propose a full-space dual-helicity decoupled metasurface and apply it to assemble a multi-folded reflective antenna (MFRA) in the microwave regime.

Elucidating the Role of Hypophosphite Treatment in Enhancing the Performance of BiVO Photoanode for Photoelectrochemical Water Oxidation.

Slow water oxidation kinetics and poor charge transport restrict the development of efficient BiVO photoanodes for photoelectrochemical (PEC) water splitting. Oxygen vacancy as an effective strategy can significantly enhance charge transport and improve conductivity in semiconductor photoanodes. Herein, we obtained BiVO photoanodes with appropriate oxygen vacancy by treating them with hypophosphite, which significantly improved the PEC performance.

Human airway-like multilayered tissue on 3D-TIPS printed thermoresponsive elastomer/collagen hybrid scaffolds.

Developing a biologically representative complex tissue of the respiratory airway is challenging, however, beneficial for treatment of respiratory diseases, a common medical condition representing a leading cause of death in the world. This in vitro study reports a successful development of synthetic human tracheobronchial epithelium based on interpenetrated hierarchical networks composed of a reversely 3D printed porous structure of a thermoresponsive stiffness-softening elastomer nanohybrid impregnated with collagen nanofibrous hydrogel. Human bronchial epithelial cells (hBEpiCs) were able to attach and grow into an epithelial monolayer on the hybrid scaffolds co-cultured with either human bronchial fibroblasts (hBFs) or human bone-marrow derived mesenchymal stem cells (hBM-MSCs), with substantial enhancement of mucin expression, ciliation, well-constructed intercellular tight junctions and adherens junctions.

Thermoresponsive Stiffness Softening of Hierarchically Porous Nanohybrid Membranes Promotes Niches for Mesenchymal Stem Cell Differentiation.

Despite the attention given to the development of novel responsive implants for regenerative medicine applications, the lack of integration with the surrounding tissues and the mismatch with the dynamic mechanobiological nature of native soft tissues remain in the current products. Hierarchical porous membranes based on a poly (urea-urethane) (PUU) nanohybrid have been fabricated by thermally induced phase separation (TIPS) of the polymer solution at different temperatures. Thermoresponsive stiffness softening of the membranes through phase transition from the semicrystalline phase to rubber phase and reverse self-assembly of the quasi-random nanophase structure is characterized at body temperature near the melting point of the crystalline domains of soft segments.

Development data associated with effects of stiffness softening of 3D-TIPS elastomer nanohybrid scaffolds on tissue ingrowth, vascularization and inflammation .

This DiB article contains data related to the research article entitled "Cellular responses to thermoresponsive stiffness memory elastomer nanohybrid scaffolds by 3D-TIPS" (Wu et al., 2018). Thermoresponsive poly (urea-urethane) nanohybrid elastomer (PUU-POSS) scaffolds were implanted in rats for up to 3 months.

Cellular responses to thermoresponsive stiffness memory elastomer nanohybrid scaffolds by 3D-TIPS.

Increasing evidence suggests the contribution of the dynamic mechanical properties of the extracellular matrix (ECM) to regulate tissue remodeling and regeneration. Following our recent study on a family of thermoresponsive 'stiffness memory' elastomeric nanohybrid scaffolds manufactured via an indirect 3D printing guided thermally-induced phase separation process (3D-TIPS), this work reports in vitro and in vivo cellular responses towards these scaffolds with different initial stiffness and hierarchically interconnected porous structure. The viability of mouse embryonic dermal fibroblasts in vitro and the tissue responses during the stiffness softening of the scaffolds subcutaneously implanted in rats for three months were evaluated by immunohistochemistry and histology.

Data of a stiffness softening mechanism effect on proliferation and differentiation of a human bone marrow derived mesenchymal stem cell line towards the chondrogenic and osteogenic lineages.

This article contains data related to the research article entitled "Stiffness memory of indirectly 3D-printed elastomer nanohybrid regulates chondrogenesis and osteogenesis of human mesenchymal stem cells" [1] (Wu et al., 2018). Cells respond to the local microenvironment in a context dependent fashion and a continuous challenge is to provide a living construct that can adapt to the viscoelasticity changes of surrounding tissues.

Stiffness memory of indirectly 3D-printed elastomer nanohybrid regulates chondrogenesis and osteogenesis of human mesenchymal stem cells.

The cellular microenvironment is dynamic, remodeling tissues lifelong. The biomechanical properties of the extracellular matrix (ECM) influence the function and differentiation of stem cells. While conventional artificial matrices or scaffolds for tissue engineering are primarily static models presenting well-defined stiffness, they lack the responsive changes required in dynamic physiological settings.

Stiffness memory nanohybrid scaffolds generated by indirect 3D printing for biologically responsive soft implants.

Cell and tissue stiffness is an important biomechanical signalling parameter for dynamic biological processes; responsive polymeric materials conferring responsive functionality are therefore appealing for in vivo implants. We have developed thermoresponsive poly(urea-urethane) nanohybrid scaffolds with 'stiffness memory' through a versatile 3D printing-guided thermally induced phase separation (3D-TIPS) technique. 3D-TIPS, a combination of 3D printing with phase separation, allows uniform phase-separation and phase transition of the polymer solution at a large interface of network within the printed sacrificial preform, leading to the creation of full-scale scaffolds with bespoke anatomical complex geometry.