Metal deficient AlB2_{2}-type (Ti0.2_{0.2}Zr0.2_{0.2}Hf0.2_{0.2}Nb0.2_{0.2}Ta0.2_{0.2})1−δ_{1-\delta}B2_{2} high-entropy diborides with high hardness

We report the synthesis and characterization of metal deficient (Ti$_{0.2}$Zr$_{0.2}$Hf$_{0.2}$Nb$_{0.2}$Ta$_{0.2}$)$_{1-\delta}$B$_{2}$ high-entropy diborides (HEBs). A single homogeneous AlB$_{2}$-type phase is successfully obtained over the $\delta$ range of 0.03 $\leq$ $\delta$ $\leq$ 0.18. With increasing $\delta$, the unit-cell volume exhibits a nonmonotonic variation with a maximum at $\delta$ = 0.07. These metal-deficient HEBs possess high Vickers hardness of 16.6-18.9 GPa at a load of 9.8 N and their phase stability is attributed to the increased mixing entropy. Our results not only present the first series of metal-deficient AlB$_{2}$-type HEBs, but also suggest the existence of similar multicomponent diborides.Comment: 7 pages, 4 figure

Roadmap on energy harvesting materials

Ambient energy harvesting has great potential to contribute to sustainable development and address growing environmental challenges. Converting waste energy from energy-intensive processes and systems (e.g. combustion engines and furnaces) is crucial to reducing their environmental impact and achieving net-zero emissions. Compact energy harvesters will also be key to powering the exponentially growing smart devices ecosystem that is part of the Internet of Things, thus enabling futuristic applications that can improve our quality of life (e.g. smart homes, smart cities, smart manufacturing, and smart healthcare). To achieve these goals, innovative materials are needed to efficiently convert ambient energy into electricity through various physical mechanisms, such as the photovoltaic effect, thermoelectricity, piezoelectricity, triboelectricity, and radiofrequency wireless power transfer. By bringing together the perspectives of experts in various types of energy harvesting materials, this Roadmap provides extensive insights into recent advances and present challenges in the field. Additionally, the Roadmap analyses the key performance metrics of these technologies in relation to their ultimate energy conversion limits. Building on these insights, the Roadmap outlines promising directions for future research to fully harness the potential of energy harvesting materials for green energy anytime, anywhere

Effects of temperature parameters on thermal-optical analysis of organic and elemental carbon in aerosol

Il contributo si sofferma sull\u2019uso delle opere di Sabino nella giurisprudenza antoniniana, prendendo in considerazione, in particolare, la produzione scientifica di Giuliano, Pomponio, Venuleio, Gaio, Marcello e Scevola. Tutte le citazioni dei giuristi di et\ue0 antoniniana concernenti la produzione di Sabino sono prive di indicazioni relative al luogo in cui le opinioni tramandate sono state espresse, e, pertanto, inserite da Otto Lenel in un Index locorum, quibus non indicato libro aut Sabinus aut Sabiniani laudantur. Dall\u2019analisi delle fonti, emerge che i giuristi di et\ue0 antoniniana davano conto delle opinioni espresse da Sabino, non solo attingendo direttamente alla sua produzione, ma anche attraverso le opere dei suoi auditores, Gaio Cassio Longino, Minicio, Fufidio, Urseio Feroce.Der Beitrag befasst sich mit der Verwendung der Werke des Sabinus in der Zeit der Antoninen, wobei insbesondere auf die wissenschaftlichen Schriften von Julianus, Pomponius, Venuleius, Gaius, Marcellus und Scaevola eingegangen wird. Keines der die wissenschaftlichen Schriften des Sabinus betreffenden Zitate in der Zeit der Antoninen enth\ue4lt einen Hinweis darauf, wo die u\u308berlieferten Meinungen zum Ausdruck gebracht worden sind; sie wurden daher von Otto Lenel vorsichtshalber in einen Index locorum, quibus non indicato libro aut Sabinus aut Sabiniani laudantur eingetragen. Die Analyse der Quellen zeigt, dass die Juristen im Zeitalter der Antoninen die Meinungen Sabinus nicht nur direkt seinen Werken entnommen haben, sondern auch den Werken seiner auditores, Gaius Cassius Longinus, Minicius, Fufidius, Urseius Ferox

Effects of temperature parameters on thermal-optical analysis of organic and elemental carbon in aerosol

Thermal-optical analysis (TOA) is a popular method to determine aerosol elemental carbon (EC) and organic carbon (OC) collected on quartz fiber filter. However, temperature protocol adopted in TOA has great effects on OC and EC results. The purpose of this study is to investigate and quantify the effects of maximum temperature (T (max) ) and residence time (RT) for each step in helium stage on ECOC measurements. Fourteen typical source samples and 20 ambient samples were collected and six temperature programs were designed for this study. It was found that EC value decreases regularly as T (max) ascends, i.e., EC results from T (max) of 650A degrees C, 750A degrees C and 850A degrees C are 0.89 +/- 0.06, 0.76 +/- 0.10, 0.62 +/- 0.13 times EC value from T (max) of 550A degrees C, respectively, and the magnitude of EC drop (EC (d) , percent) is significantly correlated with OC abundance in total carbon (R (OC/TC) ), expressed as EC (d) = 66.8R (OC/TC) - 14.4 (r = 0.87); pyrolized OC (POC) values are also sensitive to T (max) , but there are various trends for samples with different OC constituents. On average of the samples studied here, prolonged RT reduces EC values by only 3%, almost negligible compared to the effect of T (max) , and reduces POC by 9%, much less than that by previous report