Environmental Controls on Multi-Scale Dynamics of Net Carbon Dioxide Exchange From an Alpine Peatland on the Eastern Qinghai-Tibet Plateau

Peatlands are characterized by their large carbon storage capacity and play an essential role in the global carbon cycle. However, the future of the carbon stored in peatland ecosystems under a changing climate remains unclear. In this study, based on the eddy covariance technique, we investigated the net ecosystem CO2 exchange (NEE) and its controlling factors of the Hongyuan peatland, which is a part of the Ruoergai peatland on the eastern Qinghai-Tibet Plateau (QTP). Our results show that the Hongyuan alpine peatland was a CO2 sink with an annual NEE of -226.61 and -185.35 g C m(-2) in 2014 and 2015, respectively. While, the non-growing season NEE was 53.35 and 75.08 g C m(-2) in 2014 and 2015, suggesting that non-growing seasons carbon emissions should not be neglected. Clear diurnal variation in NEE was observed during the observation period, with the maximum CO2 uptake appearing at 12:30 (Beijing time, UTC+8). The Q(10) value of the non-growing season in 2014 and 2015 was significantly higher than that in the growing season, which suggested that the CO2 flux in the non-growing season was more sensitive to warming than that in the growing season. We investigated the multi-scale temporal variations in NEE during the growing season using wavelet analysis. On daily timescales, photosynthetically active radiation was the primary driver of NEE. Seasonal variation in NEE was mainly driven by soil temperature. The amount of precipitation was more responsible for annual variation of NEE. The increasing number of precipitation event was associated with increasing annual carbon uptake. This study highlights the need for continuous eddy covariance measurements and time series analysis approaches to deepen our understanding of the temporal variability in NEE and multi-scale correlation between NEE and environmental factors

Perovskite and organic solar cells fabricated by inkjet printing: progress and prospects

Inkjet printing (IJP) technology, adapted from home and office printing, has proven to be an essential research tool and industrial manufacturing technique in a wide range of printed electronic technologies, including optoelectronics. Its primary advantage over other deposition methods is the low-cost and maskless on-demand patterning, which offers unmatched freedom-of-design. Additional benefits include the efficient use of materials, contactless high-resolution deposition, and scalability, enabling rapid translation of learning from small-scale, laboratory-based research into large-scale industrial roll-to-roll manufacturing. In the development of organic solar cells (OSCs), IJP has enabled the printing of many of the multiple functional layers which comprise the complete cell as part of an additive printing scheme. Although IJP is only recently employed in perovskite solar cell (PeSC) fabrication, it is already showing great promise and is anticipated to find broader application with this class of materials. As OSCs and PeSCs share many common functional materials and device architectures, this review presents a progress report on the IJP of OSCs and PeSCs in order to facilitate knowledge transfer between the two technologies, with critical analyses of the challenges and opportunities also presented

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Viscosity and thermal expansion of soda-lime-silica glass doped with Gd2O3 and Y2O3

In order to reveal the effects of rare earth elements on the rheological behavior of silicate melt, the properties of viscosity and thermal expansion of soda-lime-silica glass doped with Gd2O3 and Y2O3 were investigated by the rotating crucible viscometer and dilatometry. The results show that, introduction of Gd2O3 and Y2O3 increases the coefficient of thermal expansion and decreases viscosity of soda-lime-silica glass. When the amount of Gd2O3 and Y2O3 increases from 0 to 1.00 mol%, the coefficient of thermal expansion of soda-lime-silica glass increases firstly from 7.67 to 7.79 and 8.05, and then decreases to 7.78 and 7.66 ( x 10 -6 C-1) respectively. In the case of melting temperature, its value decreases from 1830K to 1714 K, and then elevates to 1727 K as the content of Gd2O3 up to 1.00 mol%, however, as Y2O3 content increases from 0 to 1.00 mol% the melting temperature decreases monotonously from 1830K to 1737 K. The viscosity, melting temperature and coefficient of thermal expansion of soda-lime-silica glasses codoped with Gd2O3 and Y2O3 are larger, comparing with glasses doped solely with Gd2O3 or Y2O3. The effect of co-doping with Gd2O3 and Y2O3 on thermal expansion and viscosity properties of soda-limesilica glass, which is similar with the mixed-alkali effect in silicate glasses, is also observed

Effect of Parameters of Isopipe on the Quality of Glass Sheet Produced from Overflow Fusion Process by Numerical Simulation

A numerical model for simulation of molten glass flow with semi-implicit method for pressure-linked equations (SIMPLE) and Volume of fluid (VOF) method during the overflow fusion process was carried out by using FLUENT software. The effect of the geometry parameters of the isopipe and flow rate of molten glass on the flow patterns during overflow was investigated. The results showed that the overflow trough depth only had an effect on the flow rate distribution of glass melt around the inlet point. The tilt angle at the top of the trough had a significant effect on flow rate distribution along the length of the trough, and the desired mass distribution was achieved at the tilt angle 4°∼6°. The flow rate had a large influence on the overflow of the molten glass, which had a directive significance to the overflow down draw sheet manufacturing process

Preparation and Characterization of a Stable Nano-Sized ZnxCo1 – xAl2O4 Ink for Glass Decoration by Ink-jet Printing

A stable inorganic glass ink was prepared by mechanically grinding a mixture of a blue pigment(ZnxCo1 – xAl2O4) and low-melting-point glass powders in a specific organic solvent, which possesses a lower annealing temperature compared with ceramic ink. The ZnxCo1 – xAl2O4 based pigment was synthesized by solid-state reaction and the best sintering temperature should be at 1300°C or above according to the observation of XRD. ZnxCo1 – xAl2O4 shows blue color both in a powder form and coating. The average particle size of pigments and glass powders mixture decreases with the increase of glass powders and milling time. SEM cross-sectional images of annealed coating samples illustrate that the pigments are well dispersed in the ink layer and the glass adhesive binds well on the surface of glass plate, enhancing the mechanical strength of the ink layer. All the obtained results collectively revealed that the prepared nano-sized ZnxCo1 – xAl2O4 ink can be applied in glass decoration

Preparation and Characterization of a Stable Nano-Sized ZnxCo1 – xAl2O4 Ink for Glass Decoration by Ink-jet Printing

A stable inorganic glass ink was prepared by mechanically grinding a mixture of a blue pigment(ZnxCo1 – xAl2O4) and low-melting-point glass powders in a specific organic solvent, which possesses a lower annealing temperature compared with ceramic ink. The ZnxCo1 – xAl2O4 based pigment was synthesized by solid-state reaction and the best sintering temperature should be at 1300°C or above according to the observation of XRD. ZnxCo1 – xAl2O4 shows blue color both in a powder form and coating. The average particle size of pigments and glass powders mixture decreases with the increase of glass powders and milling time. SEM cross-sectional images of annealed coating samples illustrate that the pigments are well dispersed in the ink layer and the glass adhesive binds well on the surface of glass plate, enhancing the mechanical strength of the ink layer. All the obtained results collectively revealed that the prepared nano-sized ZnxCo1 – xAl2O4 ink can be applied in glass decoration

Effect of Parameters of Isopipe on the Quality of Glass Sheet Produced from Overflow Fusion Process by Numerical Simulation

A numerical model for simulation of molten glass flow with semi-implicit method for pressure-linked equations (SIMPLE) and Volume of fluid (VOF) method during the overflow fusion process was carried out by using FLUENT software. The effect of the geometry parameters of the isopipe and flow rate of molten glass on the flow patterns during overflow was investigated. The results showed that the overflow trough depth only had an effect on the flow rate distribution of glass melt around the inlet point. The tilt angle at the top of the trough had a significant effect on flow rate distribution along the length of the trough, and the desired mass distribution was achieved at the tilt angle 4°∼6°. The flow rate had a large influence on the overflow of the molten glass, which had a directive significance to the overflow down draw sheet manufacturing process

Environmental blue CoAl2O4 pigment co-doped by Zn2+ and Mg2+: synthesis, structure and optical properties

Nano-sized blue solid solutions ZnxMg0.5−xCo0.5Al2O4 (x = 0–0.5) have been synthesised by the Pechini method. Single-phase ZnxMg0.5−xCo0.5Al2O4 with crystallite size of ∼40 nm was identified by XRD measurement. The TG-DSC results indicated that the phase formation temperature of ZnxMg0.5−xCo0.5Al2O4 increased with the substitution of Zn2+/Mg2+ → Co2+ proceeding. The UV–vis spectra illustrated that the Zn0.3Mg0.2Co0.5Al2O4 pigment displayed the most intensive blue colour with the strongest absorbance appearing within the visible region. The FT-IR spectra suggested that the inversion degree of ZnxMg0.5−xCo0.5Al2O4 pigment reduces with the increase of Zn2+ rather than Mg2+, enabling to control the pigment colour by tuning the Zn2+ content. The FE-SEM images showed an irregular shaped morphology of ZnxMg0.5−xCo0.5Al2O4 crystal, different from the cubic-like morphology of CoAl2O4 crystal. The XPS results illustrated that the inversion of pure CoAl2O4 pigment is larger than that of Zn0.3Mg0.2Co0.5Al2O4. Both Zn0.2Mg0.3Co0.5Al2O4 and Zn0.3Mg0.2Co0.5Al2O4 show commercial potential in pigments application