Ultra-Tough Graphene Oxide/DNA 2D Hydrogel with Intrinsic Sensing and Actuation Functions.

Hydrogel devices with mechanical toughness and tunable functionalities are highly desirable for practical long-term applications such as sensing and actuation elements for soft robotics. However, existing hydrogels have poor mechanical properties, slow rates of response, and low functionality. In this work, two-dimensional hydrogel actuators are proposed and formed on the self-assembly of graphene oxide (GO) and deoxynucleic acid (DNA).

Beyond Conventional Charge Density Wave for Strongly Enhanced 2D Superconductivity in 1H-TaS Superlattices.

Noncentrosymmetric transition metal dichalcogenide (TMD) monolayers offer a fertile platform for exploring unconventional Ising superconductivity (SC) and charge density waves (CDWs). However, the vulnerability of isolated monolayers to structural disorder and environmental oxidation often degrade their electronic coherence. Herein, an alternative approach is reported for fabricating stable and intrinsic monolayers of 1H-TaS sandwiched between SnS blocks in a (SnS)TaS van der Waals (vdW) superlattice.

Direct growth of wafer-scale highly oriented graphene on sapphire.

Direct chemical vapor deposition (CVD) growth of wafer-scale high-quality graphene on dielectrics is of paramount importance for versatile applications. Nevertheless, the synthesized graphene is typically a polycrystalline film with high density of uncontrolled defects, resulting in a low carrier mobility and high sheet resistance. Here, we report the direct growth of highly oriented monolayer graphene films on sapphire wafers.

Printable two-dimensional superconducting monolayers.

Two-dimensional superconductor (2DSC) monolayers with non-centrosymmetry exhibit unconventional Ising pair superconductivity and an enhanced upper critical field beyond the Pauli paramagnetic limit, driving intense research interest. However, they are often susceptible to structural disorder and environmental oxidation, which destroy electronic coherence and provide technical challenges in the creation of artificial van der Waals heterostructures (vdWHs) for devices. Herein, we report a general and scalable synthesis of highly crystalline 2DSC monolayers via a mild electrochemical exfoliation method using flexible organic ammonium cations solvated with neutral solvent molecules as co-intercalants.

Complex dynamics and enhanced photosensitivity in a modified Belousov-Zhabotinsky reaction.

This study presents an experimental investigation of nonlinear dynamics in a modified Belousov-Zhabotinsky (BZ) reaction, in which the addition of 1,4-benzoquinone induced various complex behaviors such as mixed-mode oscillations and consecutive period-adding bifurcations. In addition, the presence of 1,4-benzoquinone significantly enhanced the photosensitivity of the ferroin-catalyzed BZ system, in which light-induced transitions between simple and complex oscillations have been achieved. Mechanistic study suggests that the influence of benzoquinone may arise from its interactions with the metal catalyst ferroin/ferriin, where cyclic voltammograms illustrate that the presence of benzoquinone causes an increase in the redox potential of ferroin/ferriin couple, which may consequently alternate the oxidation and reduction paths of the catalyst.

Coexistence of two bifurcation regimes in a closed ferroin-catalyzed Belousov-Zhabotinsky reaction.

The ferroin-catalyzed Belousov-Zhabotinsky (BZ) reaction was studied in a batch reactor under anaerobic conditions and was found to evolve through two separated regimes of complex oscillations. Significantly, the two bifurcation regimes exhibited qualitatively different dependence on compositions of the reaction mixture, i.e.

Transient complex oscillations in a closed chemical system with coupled autocatalysis.

In this study, hydroquinone was introduced to the classic Belousov-Zhabotinsky (BZ) reaction to build up coupled autocatalytic feedbacks. Various complex dynamical behaviors including successive period-adding bifurcations, irregular oscillations, and frequency modulations were observed in the coupled reaction system. Not only the complexity of oscillations but also the time period during which complex oscillations persist were found to depend greatly on the initial concentration of hydroquinone, which was expected to manifest the coupling strength in the studied system.

[Determination of zinc in relish by derivate flame atomic absorption spectrometry with microsampling pulse nebulization].

A simple, rapid, microsampling method for the determination of zinc in relish by derivative FAAS is described. The influences of microsampling volume and other factors are discussed. The detection limit and sensitivity of the proposed method are 0.