Revisiting Vibrational Circular Dichroism Spectra of (S)-(+)-Carvone and (1S,2R,5S)-(+)-Menthol Using SimIR/VCD Method

The VCD spectra of (<i>S</i>)-(+)-carvone and (1<i>S</i>,2<i>R</i>,5<i>S</i>)-(+)-menthol are recalculated using the DFT method with extended conformation and configuration spaces. The calculated individual and averaged spectra are compared against observed ones using the previously reported similarity index, <i>S</i>_V. It is found that the <i>S</i>_V population forms approximately two normal distributions, depending on whether a spectrum matches the observed one or not. This statistical character can be used to estimate the error in absolute configuration (AC) assessments. To avoid erroneous AC assignments and incomplete conformation searching, it is advisible to employ a minimum |<i>S</i>_V| of 0.2 and maximize it using conformation averaging. It is demonstrated that this approach is suitable and robust for flexible chiral molecules

Efficient Removal of Anionic Radioactive Pollutant from Water Using Ordered Urea-Functionalized Mesoporous Polymeric Nanoparticle

A urea-functionalized ordered mesoporous polymeric nanoparticle for removing the perrhenate anion ReO₄^– as the surrogate of the particularly intractable anion radioactive pollutant TcO₄^– was demonstrated in the present study. This nanomaterial (denoted as urea-MPN) was produced for the first time by a surfactant-directed urea-phenol-formaldehyde resol oligomers self-assembly protocol under hydrothermal condition. The obtained urea-MPN possessed the uniform nanosized spherical morphology with a 3D interconnected ordered cubic mesoporous structure. Also, the urea functional groups were succefully embedded in the polymer framework without the alteration of the molecular configuration. Meanwhile, it exhibited excellent β radiation resistance up to 200 kGy dose. We employed the perrhenate anion ReO₄^– to test its potential for the removal of anionic radioactive pollutant TcO₄^– from water. Interestingly, the optimized urea-MPN nanocomposite achieved the high removal efficiency at a low concentration of 0.25 mM within a short contact time of 30 min. The control experimental results revealed that the short nanoscale pore channels and the hydrophobic mesopore surface facilitated the hydrogen-bonding interaction between the charge-diffuse ReO₄^– tetrahedral oxoanion and the urea moieties in the framework of urea-MPN, accounting for the rapid and effective removal performance in pure water. Importantly, it can selectively capture ReO₄^– in the presence of different competitive anions including NO₃^–, CO₃^2–, SO₄^2–, and PO₄^3–. This attractive capability of this unique nanosized mesoporous polymeric sorbent will pave the way for the diverse applications in the decontamination of nuclear wastes in a more economical and sustainable manner

Surface-Stress-Induced Phase Transformation of Ultrathin FeCo Nanowires

Ultrathin metal nanowires have attracted wide attention becau se oftheir unique anisotropy and surface-to-volume effects. In this study, we use ultrathin Au nanowires as the templating core to epitaxially grow magnetic iron–cobalt (FeCo) shell through metal-redox with the control on their thickness and stoichiometry. Large surface-stress-induced phase transformation in Au nanowires triggers and stabilizes metastable tetragonal FeCo nanostructure to enhance its magnetic anisotropy and coercivity. Meanwhile, under illumination, plasmon-induced hotspot in ultrathin Au nanowires enables the light-control on magnetic characteristics of FeCo shell. This study demonstrates the feasibility of surface-stress-induced phase transformation to stabilize and control metastable nanostructures for enhanced magnetic anisotropy, which is one of the key properties of functional magnetic materials

Comparative Analysis of Antioxidant Activity and Functional Components of the Ethanol Extract of Lotus (<i>Nelumbo nucifera</i>) from Various Growing Regions

The variations in antioxidant activity and concentration of functional components in the ethanol extracts of lotus seeds and rhizomes based on the growing region and dryness were investigated. Free radical scavenging activity, total phenolic and flavonoid content, and concentration of several specific flavonoids and alkaloids in the ethanol extracts of lotus were measured. Antioxidant activity and its correlative total phenolic content varied characteristically depending on the growing region and dryness. High-perfomance liquid chromatography analysis showed that the ethanol extracts of lotus seeds from Vietnam (Ho Chi Minh City), raw rhizomes from Korea (Siheung), and dried rhizomes from Japan (Nigata) had the greatest specific flavonoid content. The ethanol extracts of seeds from China (Hubei), raw rhizomes from Japan (Nigata), and dried rhizomes from Korea (Siheung) had the greatest specific alkaloid content. Astragaline, rutin, isoquercetin, nuciferine, dauricine, isoliensinine, and neferine were identified in lotus rhizomes for the first time in this study

Metal-Redox Synthesis of MnBi Hard Magnetic Nanoparticles

High coercivity MnBi alloy is a promising candidate as earth abundant permanent magnet for energy-critical technologies. We report here a new metal-redox method to synthesize colloidal MnBi nanoparticles, exhibiting a saturation magnetization of 49 emu/g and coercivity of 15 kOe. It is shown that the magnetic properties of the MnBi nanoalloys can be readily modified by precursor stoichiometry, temperature ramp rate, and reaction temperature, making it a versatile scalable strategy for generation of MnBi

F1-measure of different methods.

<p>F1-measure of different methods.</p

Identification precision of different categories.

<p>Identification precision of different categories.</p

Average number of extracted features.

<p>Average number of extracted features.</p

Bamboo-like Composites of V₂O₅/Polyindole and Activated Carbon Cloth as Electrodes for All-Solid-State Flexible Asymmetric Supercapacitors

A bamboo-like nanomaterial composed of V₂O₅/polyindole (V₂O₅/PIn) decorated onto the activated carbon cloth was fabricated for supercapacitors. The PIn could effectively enhance the electronic conductivity and prevent the dissolution of vanadium. And the activation of carbon cloth with functional groups is conducive to anchoring the V₂O₅ and improving surface area, which results in an enhancement of electrochemical performance and leads to a high specific capacitance of 535.5 F/g. Moreover, an asymmetric flexible supercapacitor based on V₂O₅/PIn@activate carbon cloth and reduced graphene oxide (rGO)@activate carbon cloth exhibits a high energy density (38.7 W h/kg) at a power density of 900 W/kg and good cyclic stability (capacitance retention of 91.1% after 5000 cycles). And the prepared device is shown to power the light-emitting diode bulbs efficiently

Features extracted by CFS algorithm.

<p>Features extracted by CFS algorithm.</p