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Using first-principles calculations, we predict a new type of two-dimensional (2D) boride MB3 (M = Be, Ca, Sr), constituted by boron kagome monolayer and the metal atoms adsorbed above the center of the boron hexagons. The band structures show that the three MB3 compounds are metallic, thus the possible phonon-mediated superconductivity is explored. Based on the Eliashberg equation, for BeB3, CaB3, and SrB3, the calculated electron–phonon coupling constants λ are 0.46, 1.09, and 1.33, and the corresponding superconducting transition temperatures T c are 3.2, 22.4, and 20.9 K, respectively. To explore superconductivity with higher transition temperature, hydrogenation and charge doping are further considered. The hydrogenated CaB3, i.e., HCaB3, is stable, with the enhanced λ of 1.39 and a higher T c of 39.3 K. Moreover, with further hole doping at the concentration of 5.8 × 1011 hole/cm2, the T c of HCaB3 can be further increased to 44.2 K, exceeding the McMillan limit. The predicted MB3 and HCaB3 provide new platforms for investigating 2D superconductivity in boron kagome lattice since superconductivity based on monolayer boron kagome lattice has not been studied before.

Anti-perovskite solid-state electrolyte Li2OHCl usually exhibits orthorhombic phase and low ionic conductivity at room temperature. However, its ionic conductivity increases greatly when the temperature is up to 40 °C, while it goes through an orthorhombic-to-cubic phase transition. The cubic Li2OHCl with high ionic conductivity is stabilized at room temperature and even lower temperature about 10 °C by a simple synthesis method of wet mechanical milling. The cubic Li2OHCl prepared by this method performs an ionic conductivity of 4.27 × 10−6 S/cm at room temperature, about one order of magnitude higher than that of the orthorhombic Li2OHCl. The phase-transition temperature is decreased to around 10 °C. Moreover, it can still remain cubic phase after heat treatment at 210 °C. This work delivers a huge potential of fabricating high ionic conductivity phase anti-perovskite solid-state electrolyte materials by wet mechanical milling.

The performances such as the operating-voltage and the brightness of three types of devices: single-layer device, double-layer device and three-layer device, were examined. It is demonstrated that the I-V characteristics of single-layer device depends not on the applied voltage but instead on the electric-field strength, and the brightness increased by a factor of 50 and the operating-voltage decreased when introducing one electron transporting layer or an electron transporting layer and one hole blocking layer between the light emitting layer and the negative electrode. In fact, it is imperative to match the energy level of each layer in the electroluminescent device in order to improve its comprehensive performances.

A new method to measure an atomic wave function is discussed. It effectively solves the problem of an initially random phase of a travelling-wave laser beam. The relationship between the measured data and the atomic wave function is presented, and the wave function's reconstruction procedure is also analyzed.

The excitation spectra of the Ba 6p3/2ns (J = 1) autoionizing states with n ranging from 8 to 12 are measured using multistep laser excitation scheme. The measurements manifest that these states are strongly perturbed by the degenerate 6p1/2nl states, as the resonance profiles are structured according to the corresponding perturbing states. The experimental data are well reproduced by multichannel-quantum-defect theory, with the parameters obtained from a previous R-matrix calculation.

Whole continuous α spectra of the p-11B three-body sequential decay reaction have been measured by using a charge particle time-of-flight (TOF) spectrometer with the high-resolution passivated implanted planar silicon detector. A characteristic shape of the saddle-type distribution was obtained. The Monte Carlo calculations show that observed α spectra can be interpreted by anisotropy sequential decay process of the intermediate nucleus 8Be (1) for the p-11B reaction. In the measurement, angular distributions were obtained for proton energies at 667 and 1370 keV, respectively. Total cross-sections for the 11B(p,α)8Be(2α) reaction related to the clean fusion fuel were also reported at two bombarding energies.

A superconducting quantum interference device (squid) was made from TlBaCaCuO(TBCCO) thin film. The squid loop forms a part of the pickup loop. The squid hole is a square of about 100×100 μm. The pickup loop and the squid loop inductances are estimated to be 11 nH and 190 pH, respectively. The best value of equivalent flux noise as measured in the flux locked loop mode is 4 × 10-4 0/Hz1/2 at dc-1 Hz. The corresponding sensitivity resolution at this frequency is 9 pT/Hz1/2, about a factor 8 higher than the squid loop area.

X-ray diffraction patterns of graphite oxide (GO) are theoretically simulated as a function of the displacements of carbon atoms using the Debye—Waller factor in terms of the Warren—Bodenstein equation. The results demonstrate that GO has the turbostratically stacked structure. The high order (00l) peaks gradually disappear with the increase in atomic thermal vibrations along c-axis while the (hk0) ones weaken for the vibrations along a-axis. When the displacement deviation ua = 0.015 nm and uc = 0.100 nm the computed result is consistent with the experimental measurements.

Numerical simulations on coalescence of binary equal-sized droplets with surface tension gradients are carried out by using the front tracking method. Mixing process of the fluid from each droplet is investigated. The tangential flow caused by the Marangoni effect and the interface replacement by the fluid with small surface tension coefficient are simulated successfully. Asymmetry caused by the surface tension gradients can generate some extent of mixing within the coalesced droplet. The effects of the surface tension gradients and viscosity on the tangential velocity, replacement time of interface and mixing are investigated.

We investigate the behavior of two-dimensional atom localization in an inverted-Y system driven by one coherent field and two standing-wave fields. The position probability distribution of the atom passing through the spatial-position-dependent standing-wave fields can be determined by measuring the spontaneously emitted photon. It is found that high-precision two-dimensional atom localization can be obtained by choosing appropriate system parameters.

We investigate the dispersive and absorptive properties of an N-type four-level atomic system in three coherent fields, and consider the susceptibility mathematically. It is shown that the group velocity of the probe field exhibits sub- and super-luminal under some conditions, meanwhile the absorption coefficient keeps zero during the occurrence and transition process of sub- and super-luminal pulses.

Vibrational spectra (Raman 4000-95 cm−1 and mid-IR 4000-400 cm−1) of the atacamite-structure Ni2(OH)3Cl, including a rarely reported kind of asymmetric trimetric hydrogen bond, as a member of the geometrically frustrated material series and its deuteride Ni2(OD)3Cl are, to the best of our knowledge, reported for the first time and analyzed at room temperature. Through a comparative study of four spectra according to their crystal structural parameters, we assign OH stretching modes v(OH) in a functional group region (3700-3400 cm−1) and their deformation modes δ(NiOH/D) in the correlation peak region (900-600 cm−1) with the corresponding mode frequency ratios ωv(OD)/ωv(OH)≈73% and ωδ(NiOD)/ωδ(NiOH)≈75%, and further self-consistently suggest NiO and Ni-Cl related modes in the fingerprint region (500-200 cm−1 and 200-0 cm−1, respectively) by use of the unified six-ligand NiO5Cl and NiO4Cl2 frames. This report may contribute to the spectral analysis of other hydroxyl transition-metal halides and to the understanding of the fundamental physics of their exotic magnetic geometrical frustration property from the spectral changes around the corresponding low transition temperatures.

Feasibility of measuring stress distributions of orthotropic composite materials and structures in plane stress state by the lock-in infrared thermography technique is analyzed and stress distributions of a lap joint structure made of a kind of glass reinforced plastic composite lamination plates under tensile loadings are obtained by the lock-in infrared thermography technique. Feasibility and credibility of using this technique to measure stress distributions of orthotropic composite materials and structures in plane stress state are proved by comparing the results with the data given by the digital speckle correlation method.