The spin-to-charge conversion of the Ag / Bi interface is studied in a device in which a spin current can be injected from either side selectively. The charge voltages generated by the two ...counterpropagating spin currents show opposite signs, that is consistent with the inverse spin Hall effect rather than the well-accepted inverse Rashba-Eldestein effect in the Ag / Bi bilayer. Femtosecond laser is further employed to generate the spin-current-induced terahertz signal in a Ag / Bi bilayer, which shows no evidence for the inverse Rashba-Eldestein effect, either. This work provides a clear-cut method to identify the spin-to-charge mechanism in a Rashba electronic state and delivers new understanding for the relevant spin-transport phenomena.
Giant-Skipper butterflies from the genus Agathymus (family Hesperiidae) are unusual as their caterpillars feed inside Agave leaves. Relationships among Agathymus taxa and their names (i.e. if they ...are species, subspecies, or synonyms) are poorly understood due to phenotypic similarity. DNA sequences are promising to clarify the taxonomic questions, but it is challenging to sequence name-bearing types that are usually old specimens with poorly preserved DNA. Using next generation sequencing, we assembled mitochondrial genomes of four Agathymus mariae group holotype specimens collected more than 55 years ago and housed pinned and dry in the American Museum of Natural History (New York, NY). We compared the holotype mitogenomes to those we obtained from fresh A. mariae specimens and the sister species Agathymus micheneri. All but A. micheneri mitogenomes were highly similar to each other (more than 99% identity), suggesting that the four names chinatiensis, lajitaensis, rindgei, and gilberti proposed by H. A. Freeman in 1964 may not refer to species-level taxa. The mitogenomes grouped eastern populations (rindgei and gilberti) together and apart from the western populations (nominal mariae, chinatiensis, and lajitaensis). Mexican A. micheneri differs by about 2.5% (about 5% in the COI barcode region) from A. mariae, and is likely to be a distinct species.
Working with spin pumping and spin-torque ferromagnetic resonance measurements, we investigate the spin-charge conversion in epitaxial Bi(√3 x √3) R30º/Ag(111) structure grown by molecular beam ...epitaxy. The results show that the sign of the spin-charge conversion in our Bi/Ag structure is opposite to that in Sánchez et al. (2013), indicating the spin-charge conversion in our Bi/Ag structure is dominated by the (inverse) spin Hall effect rather than the (inverse) Rashba–Edelstein effect.
Working with spin pumping and spin-torque ferromagnetic resonance measurements, we investigate the spin-charge conversion in epitaxial Bi(3×3) R30°/Ag(111) structure grown by molecular beam epitaxy. ...The results show that the sign of the spin-charge conversion in our Bi/Ag structure is opposite to that in Sánchez et al. (2013), indicating the spin-charge conversion in our Bi/Ag structure is dominated by the (inverse) spin Hall effect rather than the (inverse) Rashba–Edelstein effect.
•Bi(√3 ×√3) R30°/Ag(111) structure was epitaxially grown on the MgO(111) substrate.•The spin-charge conversion in Bi(√3 ×√3) R30°/Ag is investigated by SP and ST-FMR.•The spin-charge conversion sign in our Bi/Ag is opposite to that in Sánchez et al. (2013).•The spin-charge conversion in Bi(√3 ×√3) R30°/Ag is dominated by (I)SHE rather than (I)REE.
For centuries, biologists have used phenotypes to infer evolution. For decades, a handful of gene markers have given us a glimpse of the genotype to combine with phenotypic traits. Today, we can ...sequence entire genomes from hundreds of species and gain yet closer scrutiny. To illustrate the power of genomics, we have chosen skipper butterflies (Hesperiidae). The genomes of 250 representative species of skippers reveal rampant inconsistencies between their current classification and a genome-based phylogeny. We use a dated genomic tree to define tribes (six new) and subtribes (six new), to overhaul genera (nine new) and subgenera (three new), and to display convergence in wing patterns that fooled researchers for decades. We find that many skippers with similar appearance are distantly related, and several skippers with distinct morphology are close relatives. These conclusions are strongly supported by different genomic regions and are consistent with some morphological traits. Our work is a forerunner to genomic biology shaping biodiversity research.
In this work, we designed and synthesized a nanocomposite comprising an amine-functionalized metal organic framework (UiO-66-NH2), a multiwalled carbon nanotube@reduced graphene oxide nanoribbon ...(MWCNT@rGONR) and a covalent organic framework (COF) synthesized using melamine and cyanuric acidmonomers via polycondensation (represented by MCA). The UiO-66-NH2/MCA/MWCNT@rGONR nanocomposite was used as a sensitive platform for an electrochemical aptasensor to detect kanamycin (kana). Owing to the rich chemical functionality, amino-rich structure and excellent electrochemical activity, the cDNA strands with terminal amino groups can not only anchor over the UiO-66-NH2/MCA/MWCNT@rGONR surface but also penetrate into the interior of porous UiO-66-NH2/MCA/MWCNT@rGONR networks. The characterization of the UiO-66-NH2/MCA/MWCNT@rGONR nanocomposite was performed by scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). Furthermore, cyclic voltammetry (CV) and square wave voltammetry (SWV) were employed for the electrochemical performance study of this biosensor. The results indicated that the UiO-66-NH2/MCA/MWCNT@rGONR nanocomposite exhibited high bioaffinity toward the aptamer and the lowest limit of detection at 13 nM (S/N = 3) within a linearity of the kana concentration of 25–900 nM. In addition, it possessed great repeatability, stability and selectivity and obtained satisfactory recovery results in the real analysis of fish meat and milk, indicating the great potential for analytical measurements in food safety.
A novel three-component domino reaction towards benzothiophene fused pyrrolidone derivatives was developed in an environmentally benign manner. The reaction proceeded well in aqueous media, and ...delivered the desired products in high yields with excellent selectivity. Density functional calculations located a multi-step reaction pathway and identified the intramolecular nucleophilic addition step to be the rate-determining step.
A novel three-component domino reaction towards benzothiophene fused pyrrolidone derivatives was developed in an environmentally benign manner.
This article studies the Hamming distances and association schemes of orthogonal arrays. We present a general method of constructing mixed schematic saturated orthogonal arrays of strength two ...produced from saturated symmetric orthogonal arrays by using the expansive replacement method. As applications of the method, we obtain many new mixed schematic saturated orthogonal arrays. Some examples are given to illustrate this construction method.
Biologists marvel at the powers of adaptive convergence, when distantly related animals look alike. While mimetic wing patterns of butterflies have fooled predators for millennia, entomologists ...inferred that mimics were distant relatives despite similar appearance. However, the obverse question has not been frequently asked. Who are the close relatives of mimetic butterflies and what are their features? As opposed to close convergence, divergence from a non-mimetic relative would also be extreme. When closely related animals look unalike, it is challenging to pair them. Genomic analysis promises to elucidate evolutionary relationships and shed light on molecular mechanisms of divergence. We chose the firetip skipper butterfly as a model due to its phenotypic diversity and abundance of mimicry. We sequenced and analysed whole genomes of nearly 120 representative species. Genomes partitioned this subfamily Pyrrhopyginae into five tribes (1 new), 23 genera and, additionally, 22 subgenera (10 new). The largest tribe Pyrrhopygini is divided into four subtribes (three new). Surprisingly, we found five cases where a uniquely patterned butterfly was formerly placed in a genus of its own and separately from its close relatives. In several cases, extreme and rapid phenotypic divergence involved not only wing patterns but also the structure of the male genitalia. The visually striking wing pattern difference between close relatives frequently involves disappearance or suffusion of spots and colour exchange between orange and blue. These differences (in particular, a transition between unspotted black and striped wings) happen recurrently on a short evolutionary time scale, and are therefore probably achieved by a small number of mutations.
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