Gamma-Ray Irradiation Stability of Zero-Dimensional Cs₃Cu₂I₅ Metal Halide Scintillator Single Crystals

Zero-dimensional Cs3Cu2I5 is one of the most promising metal halide scintillators due to its large Stokes shift, photoluminescence quantum yields, freedom from toxic elements, and excellent energy spectrum resolution. To unlock the full potential of Cs3Cu2I5 as an effective alternative to traditional scintillators for gamma-ray detection, the irradiation stability of Cs3Cu2I5 single crystals under 60Co gamma rays with a maximum accumulated dose of 800 krad was explored. Although the luminescence mechanism remained unchanged after irradiation, the optical properties of Cs3Cu2I5 single crystals demonstrated a dose-dependent change at low accumulated doses (<600 krad). However, a further increase in the accumulated dose did not lead to more severe degradation and even slight performance recovery occurred. Electron paramagnetic resonance and theoretical calculation results revealed that the irradiation-induced Cs+-related Frenkel defects contribute to performance degradation. These results shed light on the microscopic mechanism of gamma-ray irradiation damage of Cs3Cu2I5 single crystal and provide guidance to their real application

Uniform Tellurium Doping in Black Phosphorus Single Crystals by Chemical Vapor Transport

Doping has been a reliable way to improve the properties of black phosphorus (BP). However, a uniform and large amount of doping in BP remains a challenge. Herein, the synthesis of tellurium-doped black phosphorus (Te-doped BP) single crystals with high crystalline quality is achieved by the chemical vapor transport reaction method. The synthetic route enables a uniform and relatively large amount (up to 0.5% atomic ratio) of Te-doping in BP single crystals. The electrocatalytic oxygen evolution reaction (OER) properties of few-layer Te-doped BP nanosheets prepared by liquid exfoliation were also investigated for the first time. Electrochemical tests demonstrated that the OER onset-potential of undoped and Te-doped BP nanosheets was 1.63 and 1.49 V, respectively. The result implies that doping provides an effective route to enhance the electrochemical OER performance of BP

Size Dependent Mechanical Properties of Monolayer Densely Arranged Polystyrene Nanospheres

In contrast to macroscopic materials, the mechanical properties of polymer nanospheres show fascinating scientific and application values. However, the experimental measurements of individual nanospheres and quantitative analysis of theoretical mechanisms remain less well performed and understood. We provide a highly efficient and accurate method with monolayer densely arranged honeycomb polystyrene (PS) nanospheres for the quantitatively mechanical characterization of individual nanospheres on the basis of atomic force microscopy (AFM) nanoindentation. The efficiency is improved by 1–2 orders, and the accuracy is also enhanced almost by half-order. The elastic modulus measured in the experiments increases with decreasing radius to the smallest nanospheres (25–35 nm in radius). A core–shell model is introduced to predict the size dependent elasticity of PS nanospheres, and the theoretical prediction agrees reasonably well with the experimental results and also shows a peak modulus value

Confined Self-Assembly of Asymmetric Diblock Copolymers within Silica Nanobowl Arrays

The confined self-assembly of asymmetric diblock copolymer polystyrene-<i>block</i>-poly­(methyl methacrylate) (PS-<i>b</i>-PMMA) within an array of silica nanobowls prepared using a colloidal spheres templating technique is investigated. By manipulation of the nanobowl size, block copolymer (BCP) thickness, and interfacial interaction, a rich variety of ordered BCP nanostructures not accessible in the bulk system or under other confinements are obtained, resulting in hierarchically ordered nanostructures

Steady-state level of key glycolytic genes.

<p><b><i>A</i></b>, northern blot analysis of <i>HXK2</i>, <i>PFK1</i> and <i>PYK1</i> transcription levels. The nuclear encoded 25S rRNA was hybridized as an internal control. <b><i>B</i></b>, relative expression levels of these genes were calculated by three determinations. <b><i>C</i></b>, translational levels of hexokinase in each strain, tubulin was as an internal control. <b><i>D</i></b>, calculation of the relative expression level of hexokinase.</p

<i>In vivo</i> staining of the mitochondrion to measure the membrane potential by Rhodamine 123 dyes.

<p>2×10⁶ cells in 1 ml supernatant were incubated with Rhodamine 123 (5 µg/ml) for 20 min at 30°C. Cell pellets were resuspended in 20 µl PBS and visualized with Carl Zeiss 710 LSM microscopy. The relative fluorescence signal of each strain is shown in the right panel.</p

Growth activities of different yeast strains.

<p><b><i>A</i></b>, Series dilutions of each strain were spotted onto a 2% glucose medium (YPD) and the plate was incubated at 30°C for 72 hours. <b><i>B</i></b>, Growth curves analysis of yeast strains in the absence of neomycin in 20 hours. <b><i>C</i></b>, Growth activities of each strain when grown on medium containing neomycin after 72 hours incubation. <b><i>D</i></b>, Growth curves of strains cultured in YPD containing 32 µg/ml neomycin.</p

Secondary structure of small rRNA decoding sites in yeast and human mitochondria.

<p><b><i>A</i></b>, secondary structure of <i>E. coli</i> small ribosome rRNA decoding site. <b><i>B</i></b>, wild type and P^R mutant forms of yeast 15S rRNA decoding sites, and the base-pair affected by P^R mutation are indicated by arrowheads. <b><i>C</i></b>, the corresponding regions of human mitochondrial 12S rRNA are shown as the wild type version and versions containing A1555G and C1494T mutations, respectively.</p

Piezoelectric Property of a Tetragonal (Ba,Ca)(Zr,Ti)O₃ Single Crystal and Its Fine-Domain Structure

A tetragonal (Ba,Ca)­(Zr,Ti)­O₃ (BCZT) single crystal was grown by a flux method, and the piezoelectric coefficient (<i>d</i>₃₃) was characterized. The piezoelectric response was proved to be associated with polarization extension, which was successfully used to explain the variation in <i>d</i>₃₃^*. From the intrinsic aspect, the compositional effect on Landau free-energy profiles was discussed, showing an “extender” nature of the as-grown crystal and the increasing tendency of structural instability toward the morphotropic phase boundary. From the extrinsic aspect, the evolution of domain structure under various external fields (electric and temperature) was studied, revealing that the fine-domain structure of the as-grown BCZT single crystal was stable to E-field and temperature. The results manifest possibilities of further improving the piezoelectric property of the BCZT single crystal, which requires optimization of the crystal growth technique in future work

Self-Powered Ultrabroadband Photodetector Monolithically Integrated on a PMN–PT Ferroelectric Single Crystal

Photodetectors capable of detecting two or more bands simultaneously with a single system have attracted extensive attentions because of their critical applications in image sensing, communication, and so on. Here, we demonstrate a self-powered ultrabroadband photodetector monolithically integrated on a 0.72Pb­(Mg_1/3Nb_2/3)­O₃–0.28PbTiO₃ (PMN–28PT) single crystal. By combining the optothermal and pyroelectric effect, the multifunctional PMN–28PT single crystal can response to a wide wavelength range from UV to terahertz (THz). At room temperature, the photodetector could generate a pyroelectric current under the intermittent illumination of incident light in absence of external bias. A systematic study of the photoresponse was investigated. The pyroelectric current shows an almost linear relationship to illumination intensity. Benefiting from the excellent pyroelectric property of PMN–28PT single crystal and the optimized device architecture, the device exhibited a dramatic improvement in operation frequency up to 3 kHz without any obvious degradation in sensitivity. Such a self-powered photodetector with ultrabroadband response may open a window for the novel application of ferroelectric materials in optoelectronics