[en] Measurement of shock temperature under high temperature and high pressure is an essential part of equations of state(EOS) research. This paper introduces a temperature diagnosis system for laser-driven shock wave experiment on the basis of SG-Ⅱ high-power laser facility. The system comprised the streaked optical pyrometer (SOP) which is high time-resolved and the spectral resolved SOP (SSOP). The VISAR system was added to measure emissivity. The on-line calibration system of temperature measurement was established simultaneously using a NIST traceable standard lamp. High time-resolved signal images of the high temperature radiation spectrum were obtained through experiments driven by high power laser on aluminum using the diagnosis system. The shock temperature of aluminum was obtained according to gray body radiation theoretical model. The measured temperature was 2.95 eV, which was close to Hugoniot temperature in SESAME library at the same shock wave velocity. The experiment result indicates that the temperature measurement system used in the experiment can diagnose the shock temperature of metallic materials effectively. (authors)

[en] Liquid hydrogen and deuterium have abundant electrical and optical properties at high pressure. A simple model to calculate the conductivity of low-Z materials was constructed. Combining the model with experiment, this paper introduces the study of the ionization and conductivity of liquid deuterium at around 70 GPa. The results show that, deuterium at this range of pressure has an ionization about 0.067%, conductivity about 2.87 × 10⁵(W·m)^-1, which means the shocked deuterium reaches a conducting state with characteristic of metallic fluid. Apparently, the transition from the insulating molecular state to metallic state of deuterium begins at a lower pressure. (authors)

[en] The mid-infrared (mid-IR) nonlinear optical (NLO) capabilities of Mg–IV–V₂ (IV = Si, Ge, Sn; V = P, As) are systematically assessed by the first-principles calculation. The results show that the compounds in this group except MgSiP₂ and MgSnP₂ have moderate birefringence values to fulfill the phase-matching conditions. In particular, MgGeP₂ and MgSiAs₂ possess relatively large band gaps and almost three to four times larger static SHG coefficients than the benchmark material AgGaSe₂, exhibiting good potential for mid-IR NLO application. According to the detailed analysis of the electronic structures, it is found that the dominant SHG contributions are from the orbitals of the asymmetry anionic unit [IV–V₂]²⁻. Moreover, the further evaluation reveals that MgSiAs₂, MgGeAs₂, MgSnP₂ and MgSnAs₂ are not thermodynamically stable and the new synthesis strategy (i.e. synthesis under non-equilibrium conditions) should be considered. (paper)

[en] Lead iodide single crystal was grown by physical vapor transport method. Two radiation detectors with different configurations were fabricated from the as-grown crystal. The electrical and γ-ray response properties at room temperature of the both detectors were investigated. It is found that the dark resistivity of the detectors are respectively 3 × 10¹⁰ Ω·cm for bias electric field parallel to crystal c-axis (E//c) and 2 × 10⁸ Ω·cm for perpendicular to crystal c-axis (Eperpendicularc). The energy spectrum response measurement shows that both detectors were sensitive to ²⁴¹Am 59.5 keV γ-rays, and achieved a good energy resolution of 16.8% for the E perpendicular c-axis configuration detector with a full width at half maximum of 9.996 keV. (semiconductor materials)

[en] The effect of bromine methanol (BM) etching and NH₄F/H₂O₂ passivation on the Schottky barrier height between Au contact and semi-insulated (SI) p-Cd_1-xZn_xTe (x ∼ 0.09-0.18) was studied through current-voltage (I-V) and capacitance-voltage (C-V) measurements. Near-infrared (NIR) spectroscopy technique was utilized to determine the Zn concentration. X-ray photoelectron spectroscopy (XPS) for surface composition analysis showed that BM etched sample surface left a Te⁰-rich layer, however, which was oxidized to TeO₂ and the surface [Te]/([Cd] + [Zn]) ratio restored near-stoichiometry after NH₄F/H₂O₂ passivation. According to I-V measurement, barrier height was 0.80 ± 0.02-0.85 ± 0.02 eV for Au/p-Cd_1-xZn_xTe with BM etching, however, it increased to 0.89 ± 0.02-0.93 ± 0.02 eV with NH₄F/H₂O₂ passivation. Correspondingly, it was about 1.34 ± 0.02-1.43 ± 0.02 eV and 1.41 ± 0.02-1.51 ± 0.02 eV by C-V method

[en] Highlights: • The development of MDR bacteria and prevalence of BRIs have resulted in increased morbidity and mortality. • AMPs-based nano-formulation can be considered as the promising antimicrobial strategy in combating MDR bacteria and BRIs. • Nanotechnology promotes the clinical translation of AMPs as the next generation of antimicrobial agents. The rapid development of multidrug-resistant (MDR) bacteria due to the improper and overuse of antibiotics and the ineffective performance of antibiotics against the difficult-to-treat biofilm-related infections (BRIs) have urgently called for alternative antimicrobial agents and strategies in combating bacterial infections. Antimicrobial peptides (AMPs), owing to their compelling antimicrobial activity against MDR bacteria and BRIs without causing bacteria resistance, have attracted extensive attention in the research field. With the development of nanomaterial-based drug delivery strategies, AMPs-based nano-formulations have significantly improved the therapeutic effects of AMPs by ameliorating their hydrolytic stability, half-life in vivo, and solubility as well as reducing the cytotoxicity and hemolysis, etc. This review has comprehensively summarized the application AMPs-based nano-formulation in various bacterial infections models, including bloodstream infections (specifically sepsis), pulmonary infections, chronic wound infections, gastrointestinal infections, among others. The design of the nanomaterial-based drug delivery systems and the therapeutic effects of the AMPs-based nano-formulations in literature have been categorized and in details discussed. Overall, this review provides insights into the advantages and disadvantages of the current developed AMPs-based nano-formulations in literature for the treatment of bacterial infections, bringing inspirations and suggestions for their future design in the way towards clinical translation.

[en] Highlights: • AgGaGe₅Se₁₂ polycrystalline materials have been synthesized. • AgGaGe₅Se₁₂ single crystals with Φ30 mm × 50 mm have been obtained. • We have discussed the relationship between structure and physicochemical. • The absorptions at 3.4 and 7 µm have been eliminated after annealing. -- Abstract: AgGaGe₅Se₁₂ is a new quaternary nonlinear optical crystal which is applied to laser frequency conversion, especially converting 1.064 µm light to mid-IR range. In this work, we have synthesized the AgGaGe₅Se₁₂ polycrystal by the two-zones temperature method. By the modified Bridgman method, we have grown high-quality AgGaGe₅Se₁₂ single crystal 30 mm in diameter and 50 mm in length. The structure refinement was carried out by the Rietveld method. Besides, the XRS results were analyzed by comparing with AgGaGeS₄ and AgGaGe₅S₁₂. In addition, the non-polarized Raman spectra were recorded and the intense peaks were observed at 200 and 232 cm⁻¹. The peaks were attributed to corner-sharing (CS) and edge-sharing (ES) clusters. At last, the crystal was characterized by a high transparency in the 0.6–15 µm spectral range and the absorptions at 3.4 and 7 µm, observed in the as-grown crystal, have been eliminated after annealing. Thus, AgGaGe₅Se₁₂ is appropriate for further optical experiments and more comprehensive applications.

[en] We performed the first principle calculations on phase transitions, band structures, electronic and elastic properties for ternary compounds ZnXP₂ (X = Si, Ge, Sn) under pressure conditions. In the frame of density function theory, we used Ultrasoft pseudo-potentials and generalized gradient approximation method in our calculations. The optimized structural parameters are well consistent with available experimental and theoretical data. The enthalpy calculations show the first-order structural phase transitions (from chalcopyrite to rock-salt) happen at 46.8 GPa, 44.2 GPa, and 32.5 GPa for ZnSiP_2, ZnGeP₂ and ZnSnP₂, respectively, along with the volume collapsing and bond length decreasing. The calculations of pressure-effects on band structures, electronic properties and bonding natures show the energy gaps decrease with increased pressure and disappear at the transition pressures. This effect is related to the evolution of bonding from the mixture of covalent-ionic to mainly ionic character in the chalcopyrite and rock-salt phases, respectively. The elastic parameters are discussed in detail under pressure conditions, such as elastic constants C _ij, bulk modulus B, shear modulus G, Young’s modulus E, Poisson ratio ν and Zener anisotropy factor A. Our results indicate the tetragonal chalcopyrite is easier to be compressed than to be sheared and structural anisotropy becomes obvious under hydrostatic pressure condition. It directly leads to micro-cracks and produces mechanical variations in crystal structure, resulting in the occurrence of structure transition. Finally, we obtained the Debye temperature for chalcopyrite ZnXP₂ at ambient condition. (paper)

[en] We present an ab initio theoretical study of the electronic, linear and nonlinear optical properties of CdGeAs₂ using a pseudopotential plane-wave method. Specifically, we evaluate the band structure, density of states, charge density, the dielectric function ε(ω) and the second harmonic generation response susceptibility χ₃₁₂⁽²⁾(−2ω;ω,ω) over a large frequency range. As LDA underestimates the band gap, we have applied the GW approximation method to calculate the quasiparticle band structure and obtain an energy band gap in agreement with experiment. In this case the opening of the gap due to the GW correction can be used as scissor shift to calculate the linear and nonlinear optical properties. The intra- and inter-band contributions to the imaginary part of χ₃₁₂⁽²⁾(−2ω;ω,ω) are presented over a broad energy range. It is found that the small energy gap semiconductor CdGeAs₂ has larger values of ε₁(0) and χ₃₁₂⁽²⁾(0) than other chalcopyrite structures. - Graphical abstract: Calculated total imaginary part of χ₃₁₂⁽²⁾(−2ω;ω,ω) spectra along with the intra-(2ω)/(1ω) and inter-(2ω)/(1ω) band contributions. Highlights: ► We find that the charge density around the cation Cd of CdGeAs₂ is spherical. ► We do not have to rely on experimental gap to determine the self-energy. ► It is the first time we have calculated the SHG susceptibility using pseudopotential plane-wave. ► The SHG susceptibility beyond zero frequency was calculated.

[en] Large and heavily Ho"3"+-doped BaY_2F_8 single crystals were grown by the Czochralski method. X-ray powder diffraction was applied to analyze the phase of the crystal samples. Simultaneously, metallographic microscope, scanning electron microscopy and energy dispersive spectrometer were employed to observe and investigate defects in the as grown crystals. Two significant kinds of defects, namely cracking and impurities were discovered in the samples of Ho"3"+:BaY_2F_8 single crystals. Theoretical analyses suggested that mechanisms concerning the formation of the impurities such as bubbles and inclusions were considered to be closely related to the growth temperature and atmosphere while the former defect was primarily brought by the lattice distortion relating to the thermal stress and the impurities. Based on the results of experiments and theoretical analyses, the parameters of growth process were optimized and a crack free 20 mol% Ho"3"+:BaY_2F_8single crystal has been successfully obtained. Furthermore, the UV–Vis-IR (0.2–10 μm) absorption spectra of BaY_2F_8 single crystal and the crystal heavily doped with Ho"3"+ ions (20 mol%) have been investigated at room temperature. - Highlights: • Main reason of cleavages is the crystal lattice distortion caused by the impurities. • Lattice distortion was caused by carbon phases derived from the graphite crucible. • High quality crystal can be obtained by using CF_4 and high purity graphite crucibles. • The crystal exhibits the broader absorption band and larger absorption cross section