Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production.

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical steps for both electrolysis and fuel cell operation, especially at reduced temperatures. In this study, a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode, presenting superior electrochemical performance at 400~600 °C. More importantly, the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction, as confirmed by hydrogen permeation experiment, remarkable hydration behavior and computations

Spatial analysis of hemorrhagic fever with renal syndrome in China

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) is endemic in many provinces with high incidence in mainland China, although integrated intervention measures including rodent control, environment management and vaccination have been implemented for over ten years. In this study, we conducted a geographic information system (GIS)-based spatial analysis on distribution of HFRS cases for the whole country with an objective to inform priority areas for public health planning and resource allocation. METHODS: Annualized average incidence at a county level was calculated using HFRS cases reported during 1994–1998 in mainland China. GIS-based spatial analyses were conducted to detect spatial autocorrelation and clusters of HFRS incidence at the county level throughout the country. RESULTS: Spatial distribution of HFRS cases in mainland China from 1994 to 1998 was mapped at county level in the aspects of crude incidence, excess hazard and spatial smoothed incidence. The spatial distribution of HFRS cases was nonrandom and clustered with a Moran's I = 0.5044 (p = 0.001). Spatial cluster analyses suggested that 26 and 39 areas were at increased risks of HFRS (p < 0.01) with maximum spatial cluster sizes of ≤ 20% and ≤ 10% of the total population, respectively. CONCLUSION: The application of GIS, together with spatial statistical techniques, provide a means to quantify explicit HFRS risks and to further identify environmental factors responsible for the increasing disease risks. We demonstrate a new perspective of integrating such spatial analysis tools into the epidemiologic study and risk assessment of HFRS

Exploring the structural uniformity and integrity of protonic ceramic thin film electrolyte using wet powder spraying

Thin protonic ceramic electrolyte contributes to lower ohmic resistance and enhances electrochemical performance of protonic ceramic electrochemical cells. However, manufacturing of large-scale thin electrolyte remains a challenge. Wet powder spraying is an attractive technique to deposit \u3c10 \u3eμm thin electrolyte when advanced atomizing techniques and optimized spraying process are integrated. Here ultrasonic atomization is integrated in the wet powder spray technique to reduce the thickness of electrolyte. Moreover, a parametric study is conducted to optimize the wet powder spray process to deposit uniform and crack-free electrolyte film. It is illustrated that tuning of solid loading rates and spray passes can affect the morphology of the as-sprayed electrolyte film, enabling the structural compactness of the sintered electrolyte layer. To maintain chemical stability of the electrolyte layer during sintering, effect of sintering temperature is further investigated to produce a physically thin, structurally dense, and chemically homogeneous electrolyte layer. The protonic ceramic electrochemical cells fabricated with optimized spraying and sintering parameters demonstrate excellent performance under both fuel cell and electrolysis modes. In addition, the cells exhibit remarkable structural integrity during redox and long-term stability tests

Carbon Nanotube Supported Amorphous MoS2 via Microwave Heating Synthesis for Enhanced Performance of Hydrogen Evolution Reaction

Amorphous molybdenum disulfide (MoS2) is a promising electrochemical catalyst for hydrogen evolution reaction (HER) due to more active sites exposed on the surface compared to its crystalline counterpart. In this study, a novel fast three-minute one-pot method is proposed to prepare the single-wall carbon nanotube- (SWCNT-) supported amorphous MoS2 via a microwave heating process. Compared to traditional hydro- or solvent thermal methods to prepare MoS2 which usually consume more than 10 hours, it is more promising for fast production. An overpotential at 10 mA/cm2 of amorphous MoS2@SWCNT is 178 mV, which is 99 mV and 22 mV lower than crystalline MoS2@SWCNT and pure amorphous MoS2, respectively. After running 1000 cycles of polarization, ~2% increase in overpotential is observed, indicating its good stability. The enhanced performance results from the beneficial combination of the SWCNT substrate and the amorphous microstructures. The introduction of SWCNT increases catalyst conductivity and prevents MoS2 aggregation. The amorphous microstructures of MoS2 prepared by a microwave heating method lead to more Mo edges or active sites exposed

A novel intronic variant causing aberrant splicing identified in two deaf Chinese siblings with enlarged vestibular aqueducts

Abstract Objective We aimed to evaluate the genotype–phenotype relationship in two Chinese family members with enlarged vestibular aqueduct (EVA). Methods We collected blood samples and clinical data from each pedigree family member. Genomic DNA was isolated from peripheral leukocytes using standard methods. Targeted next‐generation sequencing and Sanger sequencing were performed to find the pathogenic mutation in this family. Minigene assays were used to verify whether the novel intronic mutation SLC26A4c.765+4A>G influenced mRNA splicing. Results Hearing loss in the patients with EVA was diagnosed using auditory tests and imaging examinations. Two pathogenic mutations, c.765+4A>G and c.919‐2A>G were detected in SLC26A4. In vitro minigene analysis confirmed that c.765+4A>G variant could cause aberrant splicing, resulting in skipping over exon 6. Conclusions The SLC26A4c.765+4A>G mutation is the causative variant in the Chinese family with EVA. Particular attention should be paid to intronic variants

Tunable LLP via Energy Transfer between Na_2–<i>y</i>(Zn_1–<i>x</i>Ga_<i>x</i>)GeO₄ Sosoloid Host and Emission Centers with the Assistance of Zn Vacancies

A series of sodium zinc gallogermanate sosoloid Na_2–<i>y</i>(Zn_1–<i>x</i>Ga_<i>x</i>)­GeO₄: <i>y</i>Tb³⁺ (<i>x</i> = 0, 0.1, 0.12, 0.15, 0.18, and 0.20; <i>y</i> = 0, 0.01, 0.02, 0.03, and 0.04) samples were successfully synthesized and their luminescence properties were investigated. It was found that Zn vacancies could be the predominant contribution to the enhancement of PL and LLP intensities when Ga³⁺ ions were introduced as solute atoms substituted the crystal sites of Zn²⁺ in Na₂ZnGeO₄ host. Zn vacancies act not only as an exciton energy-level participated in the PL process but also as trapping centers contributed to the LLP process. Furthermore, the energy transfer processes from Na₂(Zn_0.8Ga_0.2)­GeO₄ host to Tb³⁺ ions in PL and LLP were identified. Accordingly, the LLP colors changed from blue to green with increasing concentration of Tb³⁺ and the mechanism of which was proposed. Besides, after irradiation with 800 nm femtosecond pulsed laser, a blue upconversion LLP phenomenon was clearly observed in Na₂(Zn_0.8Ga_0.2)­GeO₄ for the first time. Analysis suggested that multiphoton absorption process was dominant in this upconversion luminescence, and subsequently the carriers excited into conduction band were captured by the trapping centers. Then the realization of LLP was due to the thermal stimulated recombination of holes and electrons at traps. Our results indicated that the blue-green emitting phosphor of Na₂(Zn_0.8Ga_0.2)­GeO₄: Tb³⁺ could be a new member in the family of LLP materials, which could also provide potential applications in the fabrication of optical memory

A Review on Carbon Source and Sink in Arable Land Ecosystems

Arable land ecosystems are among the most important terrestrial systems. The issues of carbon sequestration and emission reductions in arable land ecosystems have received extensive attention. Countries around the world have actively issued policies to manage arable land ecosystems. At present, more than 100 countries have made carbon neutralization target commitments. Various arable land management measures and arable land planting strategies have important impacts on the carbon storage of arable land ecosystems. Research on arable land carbon is of great significance to global climate change. This study attempts to investigate the problems and deficiencies in the current research by summarizing a number of studies, including the main methods for the quantitative research of carbon sources and sinks as well as the influencing factors in these ecosystems. In this study, it is found that due to the differences of climate patterns, soil properties and management practices in arable land ecosystems, the factors affecting carbon sources and sinks are of great heterogeneity and complexity. Generally, variations in natural factors affect the carbon balance in different regions, while human management measures, such as irrigation, fertilization and the degree of agricultural mechanization, are the leading factors causing changes to carbon sources and sinks in these ecosystems. In addition, there are still great uncertainties in the evaluation of carbon sources and sinks in these ecosystems caused by different estimation models and methods. Therefore, emphasis should be placed on model parameter acquisition and method optimization in the future. This review provides a scientific basis for understanding carbon sources and sinks in arable land ecosystems, enhancing their carbon sink capacity and guiding low-carbon agriculture on arable land