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As an excellent representative of all‐inorganic perovskite materials, CsPbBr3 has been widely used in high‐energy rays or high‐energy particles detection for its outstanding high carrier mobility and long diffusion length. The great challenges and opportunities in these fields are crystal growth technology, especially the high‐quality and large‐sized CsPbBr3 single crystals. In this work, the influences of growth parameters (temperature gradient, growth rate, cooling rate) and thermal stress by the vertical Bridgman method on the quality and performance of CsPbBr3 crystals are systematically studied. The final results show that 10°C cm−1 is the optimized temperature gradient and 0.5 mm h−1 is the suitable growth rate for CsPbBr3 crystal growth. The study also shows that a cooling rate of 10°C h−1 for the general temperature interval and 1°C h−1 for the phase transition temperature interval is helpful to balance crystal growth efficiency as well as crystal quality. Crystal cracks caused by thermal stress as well as crystal adhesion on the ampoule can be effectively solved by depositing a uniform carbon film on the ampoule in advance. The optical, electrical and detection performance are also investigated. The optical characterization in the wavelength region ranging from ultraviolet to infrared indicates the crystal has a low density of deep‐level defects and good crystal quality. The resistivity over 109 Ω cm and μτ of electrons over 10−2 cm−2 V−1 proves that the electrical performance of the crystal has met the basic requirement for nuclear radiation detection. The metal–semiconductor–metal structure Ti/Ni/CsPbBr3/Ni/Ti detector fabricated from the optimized CsPbBr3 single crystal has an energy resolution of 12.85% (137Cs, 662 keV). The purpose of this work is to provide a useful guide and reference for the future exploration of repeatable and improvable CsPbBr3 crystal growth technology. [ABSTRACT FROM AUTHOR]

The essence of wind-blown sand movement is a particle movement system driven by high Reynolds number wall turbulence in the atmospheric surface layer (ASL). Understanding this phenomenon is crucial as the law and mechanism of sand movement have not been effectively revealed at present. In this study, we utilize the high-frequency time series data from the Oceano site, a renowned location for such studies, which includes streamwise wind velocity (u), wall-normal wind velocity (w), temperature (T), and total saltation mass flux (q) to delve deeper into wind-blown sand movement. The results indicate a positive correlation between T and w. Interestingly, this correlation not only escalates with height but also intensifies with the increase of the stratification stability parameters (z/L). Sand influences the intensity ratio of each quadrant to Reynolds stress without altering the time ratio. Both the ejection and sweep processes correlate well with z/L. Similarly, q also exhibits a good correlation with z/L. The buoyancy's impact on the low-frequency fluctuations of q might be through its effect on the low-frequency fluctuations of w, enhancing the sand transport capacity of w. This discovery holds profound implications for the study of two-phase flow in ASL and the precise prediction of surface sediment transport. [ABSTRACT FROM AUTHOR]

As one of the promising room temperature nuclear radiation detection materials, the all-inorganic perovskite CsPbBr3 single crystal has been receiving much attention in recent years. Even though the performance of the CsPbBr3 detector is improving continuously, the disadvantages of detection instability have not been solved fundamentally, and this instability is mainly caused by ionic migration in the CsPbBr3 single crystal itself. In this paper, a reasonable ionic migration model is proposed based on an in-depth study of the current hysteresis phenomenon and ionic migration mechanism in the Ti/CsPbBr3/Ti detector. The model shows that the ions migrate to the anode or cathode under an external electric field, and the accumulated ions subsequently form an inverted internal electric field inside the crystal and carrier transport barriers at the metal–semiconductor interface simultaneously. The photoelectric characteristic and ionic migration activation energy (E a i o n) fitting results also prove the rationality of the ionic migration model. Furthermore, the ionic migration model can also be used to explain the left-shift of the energy response peak and the decrease in the normalized charge collection efficiency in the Ti/CsPbBr3/Ti detector. This paper systematically investigates the intrinsic origin of migrated ions and the influence of ionic migration on detection stability, which will provide a potential solution to improve detection stability by suppressing ionic migration in the near future. [ABSTRACT FROM AUTHOR]

In the atmospheric surface layer (ASL), the anisotropic characteristics of turbulence become more complex due to the strong influence of heat flux and particle motion. In this paper, the effects of stratification stability and total saltation sand flux on turbulent anisotropy of ASL wall turbulence are systematically analyzed by using high-frequency 3D velocity, temperature, and saltation sand flux measured in the field. Our results show that the temperature gradient intensifies the spanwise turbulent motion and enhances the vertical motion asymmetry. Although the buoyancy-driven turbulence enhances the spanwise variation, the momentum transfer mode between the streamwise–vertical and spanwise–vertical does not change. With the increase in instability, the large-scale motions (LSM) of the spanwise velocity may be destroyed and more spanwise small-scale motions (SSM) formed. In addition, saltation increases the sharpness, randomness, and extreme frequency of spanwise velocity distribution, but does not change the momentum transfer mode. Saltation may enlarge the fluctuation range and scale of the spanwise velocity, but may not be the main factor affecting the anisotropy of SSM. These results can deepen people's understanding of wind-blown sand movement and turbulence properties in ASL, and provides empirical data and insights that can significantly contribute to the development and refinement of turbulence models, particularly those that need to account for the complex interplay between stratification stability, saltation sand flux, and turbulence anisotropy. [ABSTRACT FROM AUTHOR]

Thallium Bromide (TlBr) single crystal detector is widely recognized as an excellent semiconductor nuclear radiation detector. And its detection performance has already reached commercial level of the majority semiconductor detector. However, the long-term stability of TlBr detector always exhibited a serious polarization effect and the commercial application of TlBr detector is heavily limited. In this paper, the polarization phenomenon, polarization mechanism and the influence of polarization effect on detection performance are systematic investigated. As the metal-semiconductor interface plays an important role in detector performance, two typical metal-semiconductor-metal structure, Au/TlBr/Au and Ti/TlBr/Ti detectors are designed and fabricated in this paper. The XPS in-situ analysis results reveal that different oxidation/reduction reactions would happen at the metal-semiconductor interface of Au/TlBr/Au and Ti/TlBr/Ti detectors. The serious polarization effect in Au/TlBr/Au detectors resulted from the aggregated [AuBr 4 ]- ion at the Au/TlBr interface. Meanwhile, the relative weaken polarization effect in Ti/TlBr/Ti detectors is ascribed to the combined effects of oxidic titanium ions (Ti3+, Ti4+) and metallic Ti–Tl layer at the Ti/TlBr interface. Thus, the detector Ti/TlBr/Ti has a relative better energy resolution and long-term stability compared to detector Au/TlBr/Au. This paper systematic investigate the polarization mechanism and the influence of polarization effects on TlBr detector performance, and this will provide a potential solution to suppress the polarization problem by electrode architecture designing in the near future. • The polarization phenomenon, polarization mechanism and the influence on detection performance are systematic investigated. • Two typical MSM structure, Au/TlBr/Au and Ti/TlBr/Ti detectors are designed and fabricated in this work. • A XPS in-situ measure technology is used to study the reaction mechanism at the interface of Au/TlBr and Ti/TlBr. • The serious polarization effect in Au/TlBr/Au detectors resulted from the aggregated [AuBr 4 ]- ion at the Au/TlBr interface. • The polarization effect of Ti/TlBr/Ti detectors is ascribed to the combined effects of ions (Ti3+, Ti4+) and Ti-Tl layer. [ABSTRACT FROM AUTHOR]

• The flower globular magnesium hydroxide (FGMH) was synthesized for the first time. • The method using trisodium citrate as crystal modifier is mild and easy to operate. • The prepared materials exhibited good dispersion and high specific surface area. • FGMH particles with rough surface solve the problem of difficult filtration. • The max-adsorption capacity of the materials uptake Ni(II) ions was 287.11 mg/g. To remove toxic Ni(II) ions from wastewater, a novel flower globular magnesium hydroxide (FGMH) was prepared by a gentle method using trisodium citrate as a crystal modifier. This material exhibited a high specific surface area. The synthesized products and adsorption mechanism for Ni(II) ions were examined by diverse characterization technologies and methods. FGMH was employed to remove Ni(II) ions by the adsorption method. The effects of various parameters, viz., the amount of adsorbent, contact time, temperature and pH, on the removal rate by the adsorbent were investigated in detail. The kinetic data fitted well with a pseudo-second-order model and experimental equilibrium adsorption data conformed to a Langmuir isotherm under optimized conditions. The optimal process parameters included 30 mg of FGMH, a 50 min contact time, pH values between 6.07 and 7.71 for the Ni(II) solution, and adsorption at room temperature for 50 mL of 80 mg/L Ni(II) solution. The percentage of removal efficiency was found to be above 92.64%, and the maximum adsorption capacity of MH was 287.11 mg/g under optimum adsorption conditions. The analyses indicated that the Ni(II) ions were chemisorbed on the FGMH surface. [ABSTRACT FROM AUTHOR]