Search

CdZnTe (CZT) is a new type of compound semiconductor that has emerged in recent years. Compared to other semiconductor materials, it possesses an ideal bandgap, high density, and high electron mobility, rendering it an excellent room-temperature composite semiconductor material for X-ray and γ-ray detectors. Due to the exceptional performance of CZT material, detectors manufactured using it exhibit high energy resolution, spatial resolution, and detection efficiency. They also have the advantage of operating at room temperature. CZT array detectors, furthermore, demonstrate outstanding spatial detection and three-dimensional imaging capabilities. Researchers worldwide have conducted extensive studies on this subject. This paper, building upon this foundation, provides a comprehensive analysis of CZT crystals and CZT array detectors and summarizes existing research to offer valuable insights for envisioning new detector methodologies. [ABSTRACT FROM AUTHOR]

Based on the panel data in Chinese provinces from 2000 to 2017, this paper first uses the parameterized quadratic function of the directional distance function to estimate carbon abatement costs of 30 provinces in China, and further studies its long-term evolutionary characteristics. Second, this paper studies the spatial distribution pattern of carbon abatement cost. The results show that the carbon abatement cost has increased as a whole during the study period. Moreover, the spatial distribution of carbon abatement costs in China shows a geographical clustering feature, and the positive spatial agglomeration is significant after 2008.

Low-carbon innovation plays an essential role in carbon reduction worldwide. This study investigates the nexus between low-carbon innovation, economic growth, and carbon emissions by the dynamic spatial Durbin model from 2007 to 2020. First, the Moran index results verify the provincial spatial agglomeration of carbon emissions. High-emission provinces concentrate in major economic zones and energy extraction areas. Second, the effect decomposition results show that long-term and short-term effects are consistent. Low-carbon innovation has a significant mitigation effect on carbon emissions in local regions, which effect, however, is not significant in the adjacent areas. The environmental Kuznets curve hypothesis is validated locally, but all provinces and cities have not reached the inflection point of the environmental Kuznets curve, and the linkage effect in adjacent regions remains insignificant. The above results have been tested to be robust. Third, the results of the mechanism analysis show that environmental policies, absorptive capacity, and financial development play a moderating role in the relationship between low-carbon innovation and carbon emissions. Finally, the heterogeneity test showed significant differences between Eastern, Central, and Western. The direct effect of low-carbon innovation exists in Eastern and central regions; the spillover effect of low-carbon innovation is only in the eastern region. In addition, corresponding measures are proposed based on the conclusions. [ABSTRACT FROM AUTHOR]

This study first attempts to use the parameterized quadratic directional distance function (DDF) approach to calculate China's provincial carbon abatement cost and carbon reduction potential (CRP) under different scenarios from 2000 to 2017. Afterward, considering three different scenarios, we analyze the spatio-temporal characteristics and the dynamic evolution pattern of CRP. We also employ spatial Durbin model (SDM) to investigate the influencing factors of CRP. The results are obtained as follows: (1) CRP across the three scenarios varies considerably across provinces and different-located groups. CRP higher areas are mainly located in the economically developed eastern coastal regions, while most provinces with low CRP are concentrated in the western region. (2) Provinces with a similar CRP showed a significant geographic agglomeration, and the agglomeration effect was strengthened first and then weakened. Simultaneously, the local spatial distribution of moderation carbon reduction potential (MCRP), fairness carbon reduction potential (FCRP), and efficiency carbon reduction potential (ECRP) shows a slight spatial polarization feature. (3) Through the SDM analysis and spillover effect decomposition, we find that improvement of regional CRP not only depends on economic development, industrial structure adjustment, and energy efficiency elevation, but also involves energy structure optimization, low-carbon innovation, and population. The low-carbon innovation provides critical support for local CRP under the efficiency scenario but restrains the local CRP under the fairness scenario. Therefore, the central government should emphasize local conditions and the ex-ante scenario assessment, strengthen regional interactive governance, optimize energy efficiency, and promote the application of clean energy to enhance CRP. [ABSTRACT FROM AUTHOR]

Rare-earth ions doped fiber lasers at 2 µm can supply various applications in daily life. In this paper, Ho3+/Yb3+ co-doped tellurite glasses were prepared by the high temperature melting method to obtain a strong 2 µm mid-infrared fluorescence emission. The characterization results of the X-ray diffraction (XRD) and differential scanning calorimeter (DSC) show that this glass possesses good crystallization resistance and thermal stability, and its ΔT is 136 °C, which can be successfully drawn. Under the 980 nm LD excitation, strong green (550 nm) and red (660 nm) up-conversion emission were obtained, meanwhile, intensive 2 µm mid-infrared emission was also achieved, and the emission intensity was significantly improved with the increase of Yb3+ concentration, when the Yb3+ content was 2.0, the 2 µm mid-infrared emission intensity was increased by about 28% compared with the content of 0.5, it should be noted that the concentration of Yb3+ is required to be strictly controlled to prevent concentration quenching. In addition, the luminescence process of Ho3+ was further elaborated through the energy transfer mechanism. All results indicate that the Ho3+/Yb3+ co-doped tellurite glass can be an attractive candidate for up-conversion and mid-infrared fiber laser materials. [ABSTRACT FROM AUTHOR]

Yb3 + / Ho3 + co-doped silicate-germanate glasses with excellent thermal properties and optical properties were prepared by a high temperature melting method. The measured parameter ΔT (134°C) >120 ° C indicates that compared with Yb3 + / Ho3 + co-doped germanate glass and Er3 + doped tellurite glass, there is a better crystallization resistance and thermal performance in Yb3 + / Ho3 + co-doped silicate-germanate glass. A 2.0-μm emission with the full-width at half-maximum of 203 nm was successfully obtained when excited by a 980-nm laser diode. Moreover, the results show that doping with an appropriate amount of Yb3 + ions can enhance the 2.0-μm emission intensity significantly. In addition, the underlying mechanism was based on fluorescence spectra. Therefore, the desirable thermal properties and 2.0-μm emission indicate that the Yb3 + / Ho3 + co-doped silicate-germanate glass is a promising candidate for mid-infrared fiber and laser material applications. [ABSTRACT FROM AUTHOR]

Fluorotellurite glasses tri-doped with Tm3+, Er3+ and Bi ions were investigated. The measured parameter ΔT (116 °C) confirmed that the prepared glasses had good stability. An ultra-broadband fluorescence emission (950–1670 nm) was observed with a full-width at half-maximum (FWHM) of 560 nm, which covered the entire bands of O, E, S, C, L and U. The 1800 nm fluorescence intensity of Tm3+/Er3+ co-doped and Tm3+/Er3+/Bi tri-doped glasses was enhanced compared to Tm3+ doped glass, which indicates that there is energy transfer between Tm3+, Er3+ and Bi ions. The maximum fluorescence lifetime of the prepared glasses was 7.39 ms, indicating the excellent fluorescence performance at 1800 nm. Additionally, the maximum absorption cross section (σ abs = 1.77 × 10−20 cm−2) and emission cross section (σ em = 7.61 × 10−20 cm−2) suggest that the Tm3+/Er3+/Bi tri-doped glasses have good optical absorption properties and high gain fluorescence emission. The above results indicate that the Tm3+/Er3+/Bi tri-doped fluorotellurite glasses have good application prospects in the field of fiber amplifiers and near-infrared lasers. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM 2.5 ) can damage airway epithelial barriers. The anion transport system plays a crucial role in airway epithelial barriers. However, the detrimental effect and mechanism of PM 2.5 on the anion transport system are still unclear. In this study, airway epithelial cells and ovalbumin (OVA)-induced asthmatic mice were used. In transwell model, the adenosine triphosphate (ATP)-induced transepithelial anion short-circuit current (I sc ) and airway surface liquid (ASL) significantly decreased after PM 2.5 exposure. In addition, PM 2.5 exposure decreased the expression levels of P2Y2R, CFTR and cytoplasmic free-calcium, but ATP can increase the expressions of these proteins. PM 2.5 exposure increased the levels of Th2-related cytokines of bronchoalveolar lavage fluid, lung inflammation, collagen deposition and hyperplasisa of goblet cells. Interestingly, the administration of ATP showed an inhibitory effect on lung inflammation induced by PM 2.5 . Together, our study reveals that PM 2.5 impairs the ATP-induced transepithelial anion I sc through downregulating P2Y2R/CFTR pathway, and this process may participate in aggravating airway hyperresponsiveness and airway inflammation. These findings may provide important insights on PM 2.5 -mediated airway epithelial injury., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)