The glacial phase, with an apparently glassy structure, can be formed by a first-order transition in some molecular-glass-forming supercooled liquids. Here we report the formation of metallic glacial ...glass (MGG) from the precursor of a rare-earth-element-based metallic glass via the first-order phase transition in its supercooled liquid. The excellent glass-forming ability of the precursor ensures the MGG to be successfully fabricated into bulk samples (with a minimal critical diameter exceeding 3 mm). Distinct enthalpy, structure, and property changes are detected between MGG and metallic glass, and the reversed “melting-like” transition from the glacial phase to the supercooled liquid is observed in fast differential scanning calorimetry. The kinetics of MGG formation is reflected by a continuous heating transformation diagram, with the phase transition pathways measured at different heating rates taken into account. The finding supports the scenario of liquid–liquid transition in metallic-glass-forming liquids.
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•Advanced oxidation of municipal wastewater by UV/H2O2, UV/PDS and UV/Chlorine.•Oxidation performance followed the order of UV/Chlorine > UV/H2O2 ≈ UV/PDS.•UV absorbance (UVA), total ...fluorescence (TF) revealed highest R2 values with TOrCs.
UV-based advanced oxidation processes (AOPs) have been widely explored to remove organic contaminants from water streams. In this lab-scale study, the removal of 17 trace organic chemicals (TOrCs) by UV/H2O2, UV/PDS and UV/Chlorine was investigated at equimolar radical promoter concentrations in municipal wastewater. Direct comparison of the UV-AOPs was conducted with eight TOrCs being resistant to direct oxidation by H2O2, PDS and chlorine and revealed a general oxidation performance following the order of UV/Chlorine > UV/H2O2 ≈ UV/PDS while UV/PDS and UV/Chlorine exhibited higher compound selectivity than UV/H2O2. However, although oxidation performance of UV/Chlorine is outstanding in comparison of the three UV-AOPs, it has to be noted that oxidation by-product (OBP) formation potential might be substantially higher during both UV/PDS and UV/Chlorine compared to UV/H2O2 which was not investigated in this study. Evaluating potential optical surrogates to predict trace organic chemical (TOrCs) removal in UV-AOPs, nine parameters were selected representing chromophore and fluorophore features of DOM including components derived by parallel factor analysis (PARAFAC) of excitation-emission matrices. UV absorbance (UVA), total fluorescence (TF) and the selected fluorescence peak P_IV revealed highest linear correlation coefficients and were therefore identified as surrogates representing underlying mechanistic reactions of each UV-AOP. As none of the surrogates directly reacted with UV irradiation, slopes of surrogate-indicator correlations for photo-susceptible TOrCs decreased towards higher oxidant dosages. Correlations for these compounds should therefore only be determined for a limited range of oxidant dosage.
By designing a structured gas density profile between the dual-stage gas jets to manipulate electron seeding and energy chirp reversal for compressing the energy spread, we have experimentally ...produced high-brightness high-energy electron beams from a cascaded laser wakefield accelerator with peak energies in the range of 200-600 MeV, 0.4%-1.2% rms energy spread, 10-80 pC charge, and ∼0.2 mrad rms divergence. The maximum six-dimensional brightness B_{6D,n} is estimated as ∼6.5×10^{15} A/m^{2}/0.1%, which is very close to the typical brightness of e beams from state-of-the-art linac drivers. These high-brightness high-energy e beams may lead to the realization of compact monoenergetic gamma-ray and intense coherent x-ray radiation sources.
HUBS: Hot Universe Baryon Surveyor Cui, W.; Chen, L.-B.; Gao, B. ...
Journal of low temperature physics,
04/2020, Letnik:
199, Številka:
1-2
Journal Article
Recenzirano
Hot Universe Baryon Surveyor (HUBS) is proposed in China as a major X-ray mission for the next decade. It is designed to be highly focused scientifically, with two primary objectives: (1) detecting ...X-ray emission from hot baryons in intergalactic medium and circumgalactic medium (CGM), and characterizing their physical and chemical properties; (2) studying, based on the observations, the accretion and feedback processes that are thought to be highly relevant to the heating and chemical enrichment of the baryons in the CGM. Because of very low densities, the signal is expected to be very weak and thus technically difficult to detect. On the other hand, the spectrum of the emission is expected to be line rich, so it would be effective for detecting the hot baryons in bright emission lines. For that, an instrument with high spectral resolution, large effective area and large field of view (FoV) would be required. HUBS will couple a TES-based X-ray imaging spectrometer to a large FoV X-ray telescope to satisfy these requirements. A preliminary design of HUBS is presented.
Summary
Sarcopenia was reported to be significantly associated with osteoporosis. In this study, we reported for the first time that sarcopenia was an independent risk predictor of osteoporotic ...vertebral compression refractures (OVCRFs). Other risk factors of OVCRFs are low bone mass density T-scores, female sex, and advanced age.
Introduction
The purpose of this study was to investigate the association between osteoporotic vertebral compression refractures (OVCRFs) and sarcopenia, and to identify other risk factors of OVCRFs.
Methods
We evaluated 237 patients with osteoporotic vertebral compression fracture who underwent percutaneous kyphoplasty (PKP) in our hospital from August 2016 to December 2017. To diagnose sarcopenia, a cross-sectional computed tomography (CT) image at the inferior aspect of the third lumbar vertebra (L3) was selected for estimating muscle mass. Grip strength was used to assess muscle strength. Possible risk factors, such as age, sex, body mass index (BMI), bone mineral density (BMD), location of the treated vertebra, anterior-posterior ratio (AP ratio) of the fractured vertebra, cement leakage, and vacuum clefts, were assessed. The multivariable analysis was used to determine the risk factors of OVCRFs.
Results
During the follow-up period, OVCRFs occurred in 64 (27.0%) patients. Sarcopenia was present in 48 patients (20.3%), including 21 OVCRFs and 27 non-OVCRFs patients. Sarcopenia was significantly correlated with advanced age, lower BMI, lower BMD, and hypoalbuminemia. Compared with non-sarcopenic patients, sarcopenic patients had higher OVCRFs risk. In univariate analysis, sarcopenia (
p
= 0.003), female (
p
= 0.024), advanced age (≥ 75 years;
p
< 0.001), lower BMD (
p
< 0.001), lower BMI (
p
= 0.01), TL junction (vertebral levels at the thoracolumbar junction) (
p
= 0.01), cardiopulmonary comorbidity (
p
= 0.042), and hypoalbuminemia (
p
= 0.003) were associated with OVCRFs. Multivariable analysis revealed that sarcopenia (OR 2.271; 95% CI 1.069–4.824,
p
= 0.033), lower BMD (OR 1.968; 95% CI 1.350–2.868,
p
< 0.001), advanced age (≥ 75 years; OR 2.431; 95% CI 1.246–4.744,
p
= 0.009), and female sex (OR 4.666; 95% CI 1.400–15.552,
p
= 0.012) were independent risk predictors of OVCRFs.
Conclusions
Sarcopenia is an independent risk predictor of osteoporotic vertebral compression refractures. Other factors affecting OVCRFs are low BMD T-scores, female sex, and advanced age.
To evaluate the cardiovascular damage of patients with COVID-19, and determine the correlation of serum N-terminal pro B-type natriuretic peptide (NT-proBNP） and cardiac troponin-I (cTnI） with the ...severity of COVID-19, and the impact of concomitant cardiovascular disease on severity of COVID-19 was also evaluated.
A cross-sectional study was designed on 150 consecutive patients with COVID-19 in the fever clinic of Tongji Hospital in Wuhan from January 19 to February 13 in 2020, including 126 mild cases and 24 cases in critical care. Both univariate and multivariate logistic regression were used to analyze the correlation of past medical history including hypertension, diabetes and coronary heart disease (CHD）, as well as the levels of serum NT-proBNP and cTnI to the disease severity of COVID-19 patients.
Age, hypersensitive C-reactive protein(hs-CRP) and serum creatinine levels of the patients were higher in critical care cases than in mild cases(all
<0.05). Prevalence of male, elevated NT-proBNP and cTnI, hy
We use correlated confocal and wide-field fluorescence microscopy to probe the interplay between local variations in charge carrier recombination and charge carrier transport in methylammonium lead ...triiodide perovskite thin films. We find that local photoluminescence variations present in confocal imaging are also observed in wide-field imaging, while intensity-dependent confocal measurements show that the heterogeneity in nonradiative losses observed at low excitation powers becomes less pronounced at higher excitation powers. Both confocal and wide-field images show that carriers undergo anisotropic diffusion due to differences in intergrain connectivity. These data are all qualitatively consistent with trap-dominated variations in local photoluminescence intensity and with grain boundaries that exhibit varying degrees of opacity to carrier transport. We use a two-dimensional kinetic model to simulate and compare confocal time-resolved photoluminescence decay traces with experimental data. The simulations further support the assignment of local variations in nonradiative recombination as the primary cause of photoluminescence heterogeneity in the films studied herein. These results point to surface passivation and intergrain connectivity as areas that could yield improvements in perovskite solar cells and optoelectronic device performance.
Bulk metallic glasses (BMGs) are of current interest worldwide in materials science and engineering because of their unique properties. Exploring BMGs materials becomes one of the hottest topics in ...the materials science field. To date, there is very active worldwide development of new BMGs, and extensive efforts have been carried out to understand and improve the glass-forming ability of metallic materials supported by large government and industry programs in North America, Asia, and Europe. Minor addition or microalloying technique, which has been widely used in other metallurgical fields, plays effective and important roles in formation, crystallization, thermal stability and property improvement of BMGs. This simple approach provides a powerful tool for the BMG-forming alloys development and design. In this paper, we present a comprehensive review of the history and the recent developments of this technique in the field of BMGs. The roles of the minor addition in the formation and the properties of the BMGs and the BMG-based composites will be discussed and summarized within the framework of thermodynamics, kinetics and microstructure. The empirical criteria, or the principles and guidelines for the applications of the technique in BMG field are outlined.
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