Variations of thermoelectric performance by electric fields in bilayer MX (M = W, Mo; X = S, Se).

A gate electrode is usually used to controllably tune the carrier concentrations, further modulating the electrical conductivity and the Seebeck coefficient to obtain the optimum thermoelectric figure of merit (ZT) in two-dimensional materials. On the other hand, it is necessary to investigate how an electric field induced by a gate voltage affects the electronic structures, further determining the thermoelectric properties. Therefore, by using density functional calculations in combination with Boltzmann theory, the thermoelectric properties of bilayer MX (M = W, Mo; X = S, Se) with or without a 1 V nm perpendicular electric field are comparatively investigated.

Thermoelectric properties of fullerene-based junctions: a first-principles study.

This study is built on density functional calculations in combination with the non-equilibrium Green's function, and we probe the thermoelectric transport mechanisms through C molecules anchored to Al nano-electrodes in three different ways, such as, the planar, pyramidal, and asymmetric surfaces. When the electrode is switched from the planar and pyramidal surfaces, the electrical conductance (σ) and electron's thermal conductance (κ) decrease almost two orders of magnitude due to the reduction of the molecule-electrode contact coupling, whereas the Seebeck coefficients (S) are reduced by ∼55%. Furthermore, the maximum electron's thermoelectric figure of merit (ZT = SσT/κ, assuming a vanishing phonon's thermal conductance) is about 0.

Strain and electric field co-modulation of electronic properties of bilayer boronitrene.

The electronic properties of bilayer strained boronitrenes are investigated under an external electric field using density functional methods. Our result is just the same as the previous conclusion: ie, that the electric field will reduce their band gaps. Except for the decrease of their band gaps, the degeneracy of π valence bands at K points will be lifted and the degenerate gap will increase with the electric field increasing.

Lipoxygenase-inhibiting phenolic glycosides and monoterpene glycosides from Paeonia lactiflora.

The EtOH extract of the roots of Paeonia lactiflora afforded a new phenolic glycoside paenoside A (1) and a new monoterpene glycoside paeonin D (2), and five known monoterpene glycosides. Their structures were elucidated on the basis of spectroscopic means and hydrolysis products. All compounds displayed inhibitory potential against enzyme lipoxygenase.

[Photostimulated luminescence and color centers research in BaCl(x)Br(2-x):Eu2+ phosphors].

Eu2+ doped BaCl(x)Br(2-x), phosphors were prepared by solid state method in the present paper. The crystal structure and luminescent properties were studied by XRD, excitation, emission, and photostimulation. The XRD patterns indicate thatthe samples are single phase of BaCl(x)Br(2-x).

[Photoelectron decay properties of doped AgCl microcrystals under chemical sensitization].

The photoelectron decay characteristic directly reflects the photographic efficiency of silver halide crystals. Measurement of the electronic decay time-resolved spectrum of silver halide microcrystals can provide important information about the photoelectron decay action in latent image formation process. In order to know the influence of shallow electron trap dopant K4 Fe (CN)6 and S+Au on photoelectron decay, the photoelectron decay time-resolved spectra of AgCl emulsion doped by K4 Fe(CN) and that doped by K4 Fe(CN) firstly and then sensitized by S+Au were detected by microwave absorption dielectric technique, which can be used to study the decay process of free photoelectrons and shallow-trapped electrons in semiconductor crystals.

[Photoelectron time-resolved spectrum and phosphor spectrum of luminescent material ZnO by microwave absorption method].

The process of decay of photo-generated electrons in the conduction band of ZnO:Zn and ZnO powder materials after excitation with a ultra-short pulse laser has been investigated in this paper by microwave absorption method. The excitation and emission spectra of ZnO:Zn were measured at room temperature. It was measured that the lifetime o photoelectrons in the materials ZnOand ZnO:Zn are 64 ns and 336 ns respectively.

[Photoelectron decay time-resolved spectrum of AgCl crystals doped with K4Ru(CN)6 complex].

Microwave absorption and film dielectric spectrum detection technology was used to study the influence of complex K4Ru (CN)6 on the photoelectron decay time-resolved spectrum of cubic AgCl crystals illuminated in this paper. The results indicate that the influence of the doping content and doping position of the complex K4Ru(CN)6 on the photoelectron decay time-resolved spectrum is evident. The photoelectron decay process of this emulsion is slowest, and the photoelectron lifetime is longest when doped with K4Ru (CN)6 of 2.

[Study on the microdischarge in dielectric barrier discharge by optical method].

The global light emission of dielectric barrier discharge with pattern mode in air was measured and compared with the global current obtained with a small resistor. The results show that the moments and the amplitudes of the pulses in light emission correspond to those in the global current, respectively. So the discharge current can be measured by optical methods.