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Anion-Responsive π-Conjugated Macrocycles That Form Ordered Structures
No full textIn this study, anion-responsive π-conjugated macrocycles were synthesized to demonstrate anion-binding and ion-pairing properties along with the ordered structures. Ion-pairing charge-by-charge assembly of a [1+2]-type complex of a macrocycle as a pseudo π-electronic anion and a countercation was revealed by single-crystal X-ray analysis. Further, two-dimensional (2D) arrays of the macrocycles bearing alkoxy chains, exhibiting anion-driven disordered structures, were constructed on a highly oriented pyrolytic graphite (HOPG) substrate as observed by scanning tunneling microscopy (STM). © 2025 The Author(s). Chemistry - An Asian Journal published by Wiley-VCH GmbH.journal articl
Structure Elucidation of New Kavalactone Dimers From Alpinia zerumbet Pericarps Using NMR Calculations
No full textAlpinia zerumbet (Pers.) B.L.Burtt & R.M.Sm, known as shell ginger, is an aromatic plant widely distributed in tropical and subtropical regions. In Guizhou Province of China, its mature fruits have been used by the Miao people for the treatment of cardiovascular diseases. Although the bioactivities of mature fruits of A. zerumbet are derived from phytochemicals in the seeds and pericarps of the plant, there remains a dearth of reports on the isolation of phytochemicals from the pericarp of A. zerumbet. In the present study, the pericarps of mature fruits of A. zerumbet were extracted, and two new kavalactone dimers, alpingsin E (1) and aniba dimer D (2), were isolated. Their structures were determined on the basis of extensive spectroscopic analysis and NMR calculations. Especially, density functional theory–based NMR chemical shift calculations were employed to elucidate and confirm the relative configuration of 1 and 2. © 2024 John Wiley & Sons Ltd.journal articl
Investigating the stability of flexible perovskite solar cell modules in heat and damp-heat environments
No full textStability of flexible perovskite solar cell (PSC) modules have been investigated in heat test and damp-heat test (DH-test) conditions. Heat-tests were performed at 85, 95, and 105 °C, while DH-test were at 85 °C/85 % relative humidity (RH), 95 °C/85%RH, and 99 °C/85%RH. For this purpose, the devices with a standard structure of “polyethylene terephthalate (PET)/Sn-doped In2O3/compact-TiO2/mesoporous-TiO2/CH3NH3PbI3/Spiro-OMeTAD/metal electrode” were fabricated. Consequently, the PSC modules were encapsulated by sandwiching front PET film with a barrier layer and back PET film with aluminum layer. Although the perovskite layer can be readily decomposed even at room temperature in the presence of water, it has been shown that devices’ stability can be significantly enhanced by proper encapsulation. In particular, the properties of the barrier film such as water vapor transmission rate play a crucial role to suppress the ingress and integration of water/humidity into the device. As expected, PSC modules showed better stability under heat-test over DH-test. However, damp-heat stability significantly improved for the samples with lower WVTRs. The flexible PSC module with WVTR of 0.005 g/m2/day showed improved stability in DH-test, which showed no critical failure, i.e., sudden degradation of solar cell parameters, even after 4200h of DH-test under 85 °C/85%RH. © 2025 The Authorsjournal articl
Propulsive and braking contribution of the lower limbs, trunk, and upper limbs during underwater undulatory swimming calculated from vortices distribution: A simulation study
No full textSwimmers propel their bodies forward by generating vortices around themselves, which produce fluid force during underwater undulatory swimming (UUS). This study aimed to investigate the propulsive and braking contributions of the vortices of the lower limbs, trunk, and upper limbs during UUS. The kinematic data and three-dimensional digital model were collected from nine male swimmers. Vortex generation was obtained using computational fluid dynamics, and the fluid force of six vortices was determined from the vortex circulation, swimmers' segment velocity, and length. Foot vortices contributed 96.7 % to producing braking fluid force during the first half of the downward kick. Vortices of the feet and the ventral side of the trunk contributed 69.3 % and 58.8 % to producing the propulsive fluid force during the last half of the downward kick, respectively. During the first half of the upward kick, the vortices of the feet and ventral side of the trunk contributed to producing the 87.3 % of propulsive and 93.3 % of braking fluid force, respectively. During the last half of the upward kick, 63.1 % of propulsive and 86.9% of braking fluid forces were produced by vortices on the ventral side of the trunk and feet, respectively. Small fluid forces and contributions were detected for vortices of the arms, lower legs, dorsal sides of the shoulders, and waist. These results indicate that the vortices of the feet and ventral side of the trunk mainly contribute to the increase and decrease in the horizontal UUS velocity. © 2025 The Author(s)journal articl
Abrasion experiments of mineral, rock, and meteorite particles: Simulating regolith particles abrasion on airless bodies
No full textThe shape of regolith particles on airless bodies, such as the Moon and asteroids, reflects the processes that occur on their surfaces. Recent studies have shown that particles on the asteroid Ryugu tend to be angular, whereas some particles on the asteroid Itokawa are rounded, with a larger portions of lunar particles also exhibiting a rounded shape. These differences are thought to result from abrasion, but experimental studies on particle abrasion have been lacking. In this study, we performed experiments simulating the abrasion caused by impact on airless bodies using minerals, rocks, and meteorites related to the Moon and asteroids. Aggregates of particles ranging in size from 1 to 2 mm (6.5 to10 g) were subjected to oscillation in a bead-milling apparatus to assess the amount of abrasion at different oscillation rates, varying from 100 to 3000 rpm for 0.33 to 720 min. The amount of abrasion increased with time and oscillation rate, following a power-law relationship. Once the oscillation rate exceeded a certain threshold, abrasion proceeded rapidly. At rates above 1000 rpm, particles floated and rubbed against each other due to the vertical oscillation of the container, leading to significant abrasion, whereas at rates below 300 rpm, the particles were constrained by Earth's gravity, resulting in minimal abrasion. This indicates that experiments conducted at ≥1000 rpm effectively simulated the abrasion that occurs on the Moon and asteroids. Scanning electron microscopy was used to observe the particles before and after the experiments, and X-ray microtomography was employed to track the shape changes of individual traceable particles and to measure the three-axial lengths of approximately160 particles. As abrasion progressed, some of the corners and edges of the particles were initially chipped, eventually leading to rounded corners, edges, and surfaces. This process corresponds to “adhesive wear” in tribology, which is caused by tangential relative motion between materials. In carbonaceous chondrite samples, particles tended to split along pre-existing cracks. The particles became smaller, their angularity decreased, and their sphericity increased, while the overall 3D shape of individual particles did not significantly change from their original form; however, the average three-axial ratio became more isotropic. These results indicate that the change in the average three-axial ratio of the Moon and Itokawa regolith particles can be explained by abrasion, as previously proposed. Based on the observed abrasion rates, we discuss the potential for abrasion to be caused by the impact-induced particle motion on the Moon and asteroids, considering models of regolith convection, excavation flow, and maximum acceleration. Although this discussion is rough and only semi-quantitative due to many assumptions, experimental errors, and uncertainties in the models, the results suggest that abrasion can occur on the Moon due to impact-induced particle motion, and that the abrasion observed on Itokawa particles may have occurred not on Itokawa itself, but on its parent body. Ryugu particles, in contrast, are more prone to cracking along pre-existing cracks rather than undergoing significant abrasion, and thus exhibit minimal signs of abrasion. © 2024journal articl
Can bilinguals’ procedural schema transfer be identified in high- and low-context cultures? A cross-cultural inference level comparison
No full textAccurate understanding of utterances is essential to avoid miscommunication in bilingual settings; however, little is known about bilinguals’ cognitive comprehension mechanisms. This study addresses whether procedural schema transfer is exhibited in bilinguals’ inferences in two different contexts. This study, based on dual-process theory (DPT), aimed to examine the relationship between bilinguals’ inference levels and thinking dispositions in English as a foreign language (EFL) and English as a second language (ESL) contexts or high- and low-context cultures. The participants comprised 34 Japanese EFL participants in Japan, and 16 ESL participants in the UK, including Japanese, Chinese, Mexican, Polish, and Italian. The results showed that procedural schema transfer was exhibited in inferences of Japanese EFL participants in a high-context culture but not in those of ESL participants living in a low-context culture. Unexpectedly, Japanese EFL participants’ Japanese inference level was positively correlated with interdependence, whereas their English inference level was negatively correlated. In contrast, Japanese ESL participants’ Japanese and English inference levels were both positively correlated with interdependence. This study is among the first to identify procedural schema transfer by focusing specifically on the relationship between bilinguals’ inference levels and thinking dispositions based on DPT. © 2025 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.journal articl
