A qualitative analysis method for multi-component gas mixtures terahertz rotational spectroscopy.

Terahertz rotational spectroscopy is one of the most effective methods of gas sensing. However, the rich and dense spectral peaks of multi-component gas mixtures in the terahertz band increase the difficulty of gas identification. A novel qualitative analysis method is proposed based on the collision broadening mechanism coupled with terahertz spectroscopy technology.

Deep-subwavelength gap modes in all-dielectric metasurfaces for high-efficiency and large-angle wavefront bending.

All-dielectric, phase-gradient metasurfaces manipulate light via a judiciously designed planar distribution of high and low refractive indices. In the established design approaches, the high-index elements play a dominant role, while the electromagnetic field existing between these elements is routinely viewed as either an incidental by-product or detrimental crosstalk. Here we propose an alternative approach that concentrates on exploring the low-index materials for wavefront shaping.

A quantitative analysis method based on collision broadening for trace gas using terahertz heterodyne spectrometer.

Quantitative analysis of trace gases is an important research field in analytical chemistry. The terahertz electronic spectrometer is one of the most powerful tools for detecting trace gas. Here, a terahertz spectrometer based on frequency multiplier chain and heterodyne detection was presented.

Directional conversion of a THz propagating wave into surface waves in deformable metagratings.

Controllable conversion between propagating light waves and surface waves (SWs) has recently attracted significant research interests. This paper demonstrates, via numerical simulation, for the first time all-dielectric SW converters that possess a tunable and directional SW conversion efficiency. The SW converters contain multiple metagratings of Si pillars embedded in a deformable substrate.

Confocal terahertz SAR imaging of hidden objects through rough-surface scattering.

Terahertz (THz) radar imaging has gained great interests in various applications due to its capability of deep penetration in some specific contents such as plastic and non-conductive materials without water. However, the image quality would be highly degraded by the scattering of the rough surfaces, which remains a challenge in the area. Here, we propose a confocal terahertz synthetic aperture radar (SAR) to alleviate the scattering issues with both improved signal-to-noise ratio (SNR) and resolution.

Structural and magnetic properties of FeGe (n = 3-12) clusters: Mass-selected anion photoelectron spectroscopy and density functional theory calculations.

The structural, electronic, and magnetic properties of FeGe (n = 3-12) clusters were investigated by using anion photoelectron spectroscopy in combination with density functional theory calculations. For both anionic and neutral FeGe (n = 3-12) clusters with n ≤ 7, the dominant structures are exohedral. The FeGe clusters have half-encapsulated boat-shaped structures, and the opening of the boat-shaped structure is gradually covered by the additional Ge atoms to form Ge cage from n = 9 to 11.

Photoelectron spectroscopy and density functional calculations of C(n)S(m)(-) (n = 2-7; m = 1, 2) clusters.

CnSm(-) (n = 2-7; m = 1, 2) clusters were investigated by using photoelectron spectroscopy combined with density functional theory calculations. We found that the vertical detachment energies of both CnS(-) and CnS2(-) (n = 2-7) clusters exhibit a strong odd-even alternation with an increasing number of carbon atoms: the VDEs of even-n clusters are higher than those of adjacent odd-n clusters. The most stable structures of the anionic and neutral CnS (n = 2-7) clusters are linear with the S atom locating at one end of the carbon chain except that the structure of C3S(-) is slightly bent.

Structural and magnetic properties of CoGe(n)- (n=2-11) clusters: photoelectron spectroscopy and density functional calculations.

A series of cobalt-doped germanium clusters, CoGe(n)(-/0) (n=2-11), are investigated by using anion photoelectron spectroscopy combined with density functional theory calculations. For both anionic and neutral CoGe(n) (n=2-11) clusters, the critical size of the transition from exo- to endohedral structures is n=9. Natural population analysis shows that there is electron transfer from the Ge(n) framework to the Co atom at n=7-11 for both anionic and neutral CoGe(n) clusters.

Photoelectron spectroscopy and ab initio calculations of small SinSm⁻ (n = 1,2; m = 1-4) clusters.

Binary cluster anions composed of silicon and sulfur elements, SinSm(-) (n = 1,2; m = 1-4), were investigated by using photoelectron spectroscopy and ab initio calculations. The vertical detachment energies and the adiabatic detachment energies of these clusters were obtained from their photoelectron spectra. The electron affinity of SiS molecule is determined to be 0.

Thermal methane activation by La(6)O(10)(-) cluster anions.

The first example of a metal oxide cluster anion, La6 O10 (-) that can activate methane under ambient conditions is reported. This reaction is facilitated by the oxygen-centered radical (O(-⋅) ) and follows the hydrogen atom transfer mechanism. The La6 O10 (-) has a high vertical electron detachment energy (VDE=4.

Smallest fullerene-like silicon cage stabilized by a V(2) unit.

We conducted a combined anion photoelectron spectroscopy and density functional theory study on V2Si20 cluster. Our results show that the V2Si20 cluster has an elongated dodecahedron cage structure with a V2 unit encapsulated inside the cage. It is the smallest fullerene-like silicon cage and can be used as building block to make cluster-assembled materials, such as pearl-chain style nanowires.

Photoelectron spectroscopy and density functional calculations of AgSi(n)- (n = 3-12) clusters.

We investigated the structural evolution and electronic properties of AgSi(n)(-) (n = 3-12) clusters using anion photoelectron spectroscopy and density functional theory calculations. The vertical detachment energies and adiabatic detachment energies of AgSi(n)(-) (n = 3-12) clusters were estimated from their photoelectron spectra. The structures of the AgSi(n)(-) (n = 3-12) clusters were tentatively assigned based on the comparison of theoretical calculations and experimental measurements.

The adsorption properties of Pb(II) and Cd(II) on functionalized graphene prepared by electrolysis method.

The functionalized graphene (GNS(PF6)) was fabricated by simple and fast method of electrolysis with potassium hexafluorophosphate solution as electrolyte under the static potential of 15 V. The characterization results of transmission electron microscopy, atom force microscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction, Raman spectroscopy and thermogravimetric analysis indicate that graphite rod was completely exfoliated to graphene layer containing 30 wt.% PF(6)- with the average thickness ca.