Mechanical metamaterials have attracted extensive attention. This paper reports a metamaterial with tunable elastic wave bandgaps based on bistable buckling structure. First, we find that deformation of two symmetric buckling shells is intrinsically asymmetric, which blocks the realisation of robust tunability. Based on an analytical model, we clarify that the mechanisms for this intrinsic asymmetricity are the bifurcations on force–deformation curves. Then we propose a superposition method of buckling shells, which can realise the symmetric deformation for robust tunable stiffness. Using this variable-stiffness oscillator, we design a metamaterial sandwich beam, and numerically and experimentally demonstrate its tunable bandgap for vibration suppression. This paper presents the unusual deformation process of buckling elements widely used for constructing metamaterials, and provides a robust way to realise metamaterials with tunable vibration bandgaps.

As a major approach for controlling electromagnetic (EM) waves, metamaterials have experienced an abundant and rapid development in the 21st century. They have provided flexible and powerful techniques for controlling EM waves and brought many unique applications that are difficult to realise with natural materials. With increasing demands on dynamic controls of the EM waves, many innovations have been conducted in both three-dimensional metamaterials and two-dimensional metasurfaces, in which the meta-atom has been gradually evolved from passive to active. In 2014, coding and digital mechanisms were initially introduced to the metamaterials, further advancing the appearance of digitally programmable metamaterials. The programmable metamaterials have shown great potentials in not only real-time manipulations of the EM waves, but also direct information processing on the EM wave level. In this article, we present an in-depth review of the programmable EM metamaterials and metasurfaces, focusing on the programmable features including theoretical concepts, implementing methods and applications in EM controls. We first give a short retrospect of traditional metamaterials and metasurfaces, followed by the concepts and detailed discussions of digital coding and field-programmable metamaterials. Then, we introduce space-domain, time-domain and space–time-domain programmable metamaterials and metasurfaces, mainly focusing on their theories, functionalities, experimental implementations, and system-level applications. Finally, we conclude the current advances of the programmable metamaterials and metasurfaces, and give a prospect for the future developments.

X-ray powder diffraction data, including unit cell parameters and space group assignment, for the ESP15228 species of C19H34O5 formula, are here reported [a = 6.0434(6), b = 12.2543(6), c = 14.0285(8) Å, α = 86.584(3), β = 85.707(10), γ = 78.801(5)°, V = 1015.2(1) Å3, Z = 2, ρcalc = 1.152 g cm−3, and space group P-1]. All measured lines were indexed and no detectable impurities were observed.

The crystal structure of butenafine hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Butenafine hydrochloride crystallizes in space group P21 (#4) with a = 13.94807(5), b = 9.10722(2), c = 16.46676(6) Å, β = 93.9663(5)°, V = 2086.733(8) Å3, and Z = 4. Butenafine hydrochloride occurs as a racemic co-crystal of R and S enantiomers of the cation. The crystal structure is characterized by parallel stacks of aromatic rings along the b-axis. Each cation forms a strong discrete N–H⋯Cl hydrogen bond. The chloride anions also act as acceptors in several C–H⋯Cl hydrogen bonds from methylene, methyl, and aromatic groups. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

In deception research, little consideration is given to how the framing of the question might impact the decision-making process used to reach a veracity judgment. People use terms such as “sure” to describe their uncertainty about an event (i.e., aleatory) and terms such as “chance” to describe their uncertainty about the world (i.e., epistemic). Presently, the effect of such uncertainty framing on veracity judgments was considered. By manipulating the veracity question wording the effect of uncertainty framing on deception detection was measured. The data show no difference in veracity judgments between the two uncertainty framing conditions, suggesting that these may operate on a robust and invariant cognitive process.

A theoretical and experimental framework for novel metamaterial with programmable damping properties is presented. This material system is able to switch between elastic-dominated and damping-dominated regimes with different overall stiffness under dynamic loading depending on the external stimulus. The unit cell combines an auxetic and a bellow-like layer separated by an interface through which the amount of media flow can be tuned depending on the lateral strain. A simplified analytical model is derived to analyse the programmable damping effect. The model is further extended with a fluid-dynamics approach to link the effective damping properties with geometrical parameters to aid with the practical design of the metamaterial. Afterward, experiments are conducted on a macroscopic level using laser-sintered unit cells to validate the functionality of the concept both with air and water as media within the unit cells. To conclude the work, initial results on microscopic-level unit cells fabricated by two-photon lithography are introduced to showcase the scalability of the concept. This work provides an experimentally validated theoretical framework for future investigations to design unit cells with programmable damping on different length scales for applications requiring tailored dynamic energy dissipation.

Shape memory polymers (SMPs) are atype of programmable materials capable of transforming their shapes in a pre-programmed way upon the application of an external stimulus. These materials have been tested for various potential applications particularly in the biomedical field for polymers with general and specific requirements. This review focuses on the recent advances in biomedical applications, including self-tightening sutures, pressure bandages, self-expansion stents, tissue engineering scaffolds, artificial muscles, drug delivery, and orthodontic archwires, after a brief description of the concepts, classifications, programming procedures, and material requirements of SMPs.

The U.S. National Committee for Crystallography (USNC/Cr) of the National Academies of Sciences, Engineering, and Medicine provided an online workshop series for researchers on the use, development, and maintenance of crystallographic and structural databases in the Spring of 2022. Encompassing macromolecular, small molecule, and powder diffraction information, the series included 11 modules each meeting for 1 or 2 days. Graduate students, postdoctoral fellows, faculty members and researchers in any of the crystallographic, diffraction, and imaging sciences affiliated with the International Union of Crystallography (IUCr) were encouraged to register and participate in the training sessions that interest them.

The crystal structure of encorafenib, C22H27ClFN7O4S, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Encorafenib crystallizes in space group P21 (#4) with a = 16.17355(25), b = 9.52334(11), c = 17.12368(19) Å, β = 89.9928(22)°, V = 2637.50(4) Å3, and Z = 4. The crystal structure consists of alternating layers of stacked halogenated phenyl rings and the other parts of the molecules perpendicular to the a-axis. One molecule participates in two strong N–H⋯N hydrogen bonds (one intra- and the other intermolecular), which are not present for the other molecule. The intermolecular hydrogen bonds link molecule 2 into a spiral chain along the b-axis. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

X-ray fluorescence (XRF) is frequently used to measure layer thickness in the micrometer range. But also X-ray diffraction (XRD) can be used in a comparable way and offers the benefit to differentiate coating layers by their crystal structure. Thus, the thickness of different oxide layers of the same element can be determined, e.g., FeO, Fe3O4, and Fe2O3 on Fe-substrate. An approach for such measurement is discussed. Furthermore, with a suitable sample stage, a spatially resolved coating thickness map can be measured in a nondestructive way. Applications and validations of the presented XRD method for the measurement of the thickness of zinc coatings on steel are given and compared with results from XRF, glow-discharge optical emission spectroscopy, and optical micrographs. In addition, the methodology was tested and validated using XRF reference standards and iron nitride and iron oxide layers.

Ageism has become a social problem in an aged society. This study re-examines an ageism affirmation strategy; the designs and plans for this study were pre-registered. Participants were randomly assigned to either an experimental group (in which they read an explanatory text about the stereotype embodiment theory and related empirical findings) or a control group (in which they read an irrelevant text). The hypothesis was that negative attitudes toward older adults are reduced in the experimental group compared with the control group. Bayesian analysis was used for hypothesis testing. The results showed that negative attitudes toward older adults were reduced in the experimental group. These findings contribute to the development of psychological and gerontological interventions aimed at affirming ageism. In addition, continued efforts to reduce questionable research practices and the spread of Bayesian analysis in psychological research are expected.

Dimethyl carbonate (DMC) is an important industrial solvent but is additionally a common component of liquid lithium-ion battery electrolytes. Pure DMC has a melting point of 277 K, so encountering solidification under outdoor climatic conditions is very likely in many locations around the globe. Even eutectic, ethylene carbonate:dimethyl carbonate commercial LiPF6 salt electrolyte formulations can start to solidify at temperatures around 260 K with obvious consequences for their performance. No structures for crystalline DMC are currently available which could be a hindrance for in situ battery studies at reduced temperatures. A time-of-flight neutron powder diffraction study of the phase behavior and crystal structures of deuterated DMC was undertaken to help fill this knowledge gap. Three different orthorhombic crystalline phases were found with a previously unreported low-temperature phase transition around 50–55 K. The progression of Pbca → Pbcm → Ibam space groups follow a sequence of group–subgroup relationships with the final Ibam structure being disordered around the central carbon atom.

When two waves interact within a rock sample, the interaction strength depends strongly on the sample’s microstructural properties, including the orientation of the sample layering. The study that established this dependence on layering speculated that the differences were caused by cracks aligned with the layers in the sample. To test this, we applied a uniaxial load to similar samples of Crab Orchard Sandstone and measured the nonlinear interaction as a function of the applied load and layer orientation. We show that the dependence of the nonlinear signal changes on applied load is exponential, with a characteristic load of 11.4–12.5 MPa that is independent of sample orientation and probe wavetype (P or S); this value agrees with results from the literature, but does not support the cracks hypothesis.