改进型ICA和SVM相结合的火山灰云遥感检测

针对独立分量分析(ICA)模型在火山灰云遥感检测中的不足,提出了一种改进型ICA即变分贝叶斯ICA (VBICA)和支持向量机(SVM)相结合的火山灰云遥感检测算法,实现了火山灰云信息的近似分离.实验结果表明,所提算法能够从中分辨率成像光谱仪(MODIS)遥感图像中检测出火山灰云目标信息,且总检测精度和Kappa系数分别达到了88.4％和0.801 1,取得了较好的检测效果.     

Transfer of Two‐Dimensional Oligonucleotide Patterns onto Stereocontrolled Plasmonic Nanostructures through DNA‐Origami‐Based Nanoimprinting Lithography

The precise functionalization of self‐assembled nanostructures with spatial and stereocontrol is a major objective of nanotechnology and holds great promise for many applications. Herein, the nanoscale addressability of DNA origami was exploited to develop a precise copy‐machine‐like platform that can transfer two‐dimensional oligonucleotide patterns onto the surface of gold nanoparticles (AuNPs) through a deliberately designed toehold‐initiated DNA displacement reaction. This strategy of DNA‐origami‐based nanoimprinting lithography (DONIL) demonstrates high precision in controlling the valence and valence angles of AuNPs. These DNA‐decorated AuNPs act as precursors in the construction of discrete AuNP clusters with desired chirality.     

Wakimoto modules for twisted multi-loop algebra of type <Emphasis Type="Italic">A</Emphasis><Subscript>1</Subscript> × <Emphasis Type="Italic">A</Emphasis><Subscript>1</Subscript>

We construct a class of modules for the twisted multi-loop algebra of type A ₁×A ₁ by applying Wakimoto free bosonic realization. We also discuss the structures and the irreducibility of the Fock space.     

Hyperfine interactions in nanocrystallized NANOPERM-type metallic glass containing Mo

NANOPERM-type alloy with chemical composition Fe₇₆Mo₈CuB₁₅ was studied by combination of ⁵⁷Fe Mössbauer spectroscopy and ⁵⁷Fe(¹⁰B, ¹¹B) nuclear magnetic resonance in order to determine distribution of hyperfine magnetic fields and evolution of relative concentration of Fe-containing crystalline phases within the surface layer and the volume of the nanocrystallized ribbons with annealing temperature. Differential scanning calorimetry revealed two crystallization stages at T_x1 ～ 510 ^°C and T_x2 ～ 640 ^°C, connected to precipitation of α-Fe and Fe(Mo,B) nanocrystals, respectively. The amorphous and partially crystalline state was obtained by annealing at several temperatures in the range 510-650 ^°C. The combination of conversion electron (CEMS) and transmission Mössbauer spectrometry (TMS) showed that annealing induces crystallization starting from both surfaces of the ribbons. For the as-quenched sample, scanning electron microscopy (SEM) and CEMS revealed significant differences in the “air” and “wheel” sides of the ribbons, crystallites were preferentially formed at the latter. While SEM micrographs of annealed samples showed various mean diameters of the crystals at opposite sides of the ribbons, the amounts of crystalline volume derived from the CEMS spectra approximately equaled. Mössbauer spectra of annealed samples contained narrow sextet ascribed to crystalline α-Fe phase, three sextets with distribution of hyperfine field assigned to the interface regions of the nanocrystals and the contribution of the amorphous phases. In-field TMS performed at 4.2 K with magnetic moments aligned by external magnetic field enabled to properly determine in particular the contribution of the amorphous phases in the samples. Resulting distributions of the hyperfine fields were compared with ⁵⁷Fe(¹⁰B, ¹¹B) nuclear magnetic resonance (NMR) spectra.     

Magnetically‐Confined Fe‐Mn Bimetallic Oxide Encapsulation as an Efficient and Recoverable Adsorbent for Arsenic(III) Removal

Synthesis of bimetallic‐oxide‐encapsulated magnetic nanoparticles is still significantly challenging and has rarely been attempted previously, due to the effects of lattice mismatch, weak chemical interactions and variances in growth rates between different components, as well as the difficulty in process control for uniform co‐deposition. In the present work, Fe‐Mn bimetallic oxide (FMBO) nanoplatelet encapsulated magnetic nanoparticles (Mag‐FeMn) are prepared by controlled engineering of the interparticle coupling of Fe₃O₄ and FMBO, with its multifunctional capabilities highlighted in terms of the potentially superior As(III) sequestration and convenient recoverability. Multiple characterization techniques are employed to examine the derived morphologies and to accurately resolve both compositionally and magnetically the hierarchical structure in detail. The synthesized magnetic composites retain highly porous structure with the main components of Fe₂O₃, FeOOH, Fe₃O₄, and Mn₃O₄. Mag‐FeMn exhibits a quite competitive high capacity for As(III) capture (56.1 mg g^–1), whereby As(III) oxidation coupled with synchronous sorption contributes to the improved performance. The unique heterostructure of FMBO encapsulation with an embedded magnetic core would be applicable to help with rational synthesis of other bimetallic oxide encapsulated magnetic nanoparticles, and definitely shows promise for the development of new nanotechnology enabled approaches for adsorption‐based water purification.     

Computational insight into asymmetric uranyl-salophen coordinated with cyclohexenone derivatives

Uranyl–salophen (U–S) complexes, as modified by unilateral benzene and coordinated with cyclohexenones substituted by methyls or fluorines in E/Z-types, were investigated using density functional theory calculations at the level of B3LYP/6–311G** basis set. The results indicated that the O of substituted cyclohexenones could coordinate with U of the asymmetric U–S complexes. When the C=C bond of cyclohexenones was located upward in the twisted salophen plane, the binding energies of the cyclohexenones to the asymmetric U–S and Wiberg bond indices (WBIs) of carbonyl oxygen to uranium (U–O) were higher than those of the C=C bonds located downward. It could be concluded that when cyclohexenones were coordinated to the asymmetric U–S, the major products would be the complexes in which the C=C bond of cyclohexenones locates upward in the configuration. Binding energies of the E-type substituted cyclohexenones to the asymmetric U–S were higher than those for the Z-type ones.