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[Display omitted] • High-quality Ga 2 O 3 heterostructures grown via LMBE with lattice/energy band matching. • Modulating APDs' voltage and dark current by adjusting MgO layer thickness. • The impact of the barrier layer on the nBn structure APDs performance was systematically studied. • The fabrication of Ga 2 O 3 -based solar-blind APDs with the current optimal performance has been achieved. Ga 2 O 3 -based solar-blind avalanche photodetectors (APDs) offer advantages such as compactness, low power consumption, and high stability. They could improve the integration and reliability of solar-blind photodetectors, and serve as a viable substitute for photomultiplier tubes (PMTs) in deep ultraviolet signal detection. We have previously demonstrated that the n-Barrier-n (nBn) structure, composed of Ga 2 O 3 /MgO/Nb:SrTiO 3 heterostructure, can efficiently reduce the dark current and enhance the reverse breakdown voltage due to the increased conduction band offsets. The barrier layer is a key factor in determining the device performance in the nBn heterostructure. Hence, we further optimize the study by varying the thickness of the barrier layer MgO to examine its effect on the devices. This modulation can affect the avalanche multiplication process, and thus enable the tuning of APDs' performance. In this paper, we present the optimized thin film growth process, and the systematic investigation of the responsivity and gain of the device with different barrier layer thicknesses. The optimal performance was achieved with 25 nm MgO thickness. We also explore the underlying mechanism to elucidate the role of the barrier layer. Our results provide insights into the influence of barrier layer thickness in the nBn structure. [ABSTRACT FROM AUTHOR]

With the continuing consumption of resources and increasingly prominent environmental issues, microalgal resource utilization has received extensive attention. In this study, based on the microalgal investigation in desert biological soil crusts (BSCs) using pyrosequencing technology, the cultivated crust microalgae were further isolated in order to obtain high quality microalgae for resource utilization. The results showed that with crust development and succession, microalgal diversity gradually decreased, including the number of operational taxonomic units (OTUs) and genus, although Microcoleus always was the dominant genera. Pyrosequencing obtained 630 OTUs of cyanobacteria, 25 OTUs of green algae and 9 OTUs of diatom; however, part of cultivated microalgae still could not yet be detected due to the DNA extraction preferences and errors caused by PCR amplification. After isolation, four strains were purified and cultivated, including two filamentous cyanobacteria Microcoleus vaginatus BSC-06 and Scytonema javanicum BSC-39, and two unicellular green algae Chlorella sp. BSC-24 and Monoraphidium dybowskii BSC-81. The two green algae grew fast (>250 mg L -1  d -1 ), and achieved high lipid productivity up to 75–85 mg L -1  d -1 , with lipid content of 28.7–39.0%, thus was considered as promising feedstock for biodiesel production. In addition, the two crust cyanobacteria could be used to construct artificial cyanobacterial soil crusts in desertification control, although their biomass accumulation was not as high as that in the green algae. Ultimately, combining biodiesel production with desertification control would not only improve desert environments, but also provide ideal places for the local microalgal resource exploitation, further promoting desert socioeconomic development. [ABSTRACT FROM AUTHOR]

In this study, based on the characteristic of lanthanide in oxygen storage capacity, a series of Pr a Ti b O x composite supports with different mole ratios of Pr to Ti and the corresponding Au catalysts were prepared - to investigate the oxidation of CO under CO 2 -rich atmosphere with lean oxygen content. A significant promotion in CO conversion rate over the catalyst with a molar ratio of Pr:Ti = 1:2 and a very high catalytic stability was also obtained. The addition of optimal Pr will make smaller gold particles, provide higher capacity in surface reactive oxygen releasing at low temperatures and weaken the deposition of carbonates in CO 2 -rich atmosphere. However, more Pr will strongly interact with gold, which leads to the majority of Au+ species in the catalysts and thus lower the catalytic activity. This study may provide a potential application of rare earth elements in sealed CO 2 -laser. [Display omitted] • The Pr a Ti b O x composites supported Au catalysts were studied for CO oxidation with CO 2 -rich feed. • The optimal catalyst was found with a molar ratio of Pr:Ti = 1:2. • Good catalytic performance correlated to the easy surface reactive oxygen releasing and weak deposition of carbonates. • The majority of Au+ species in the catalysts with higher Pr content results in worse performance. [ABSTRACT FROM AUTHOR]