Low absorptance of transition metal dechalcongenides has limited their potential applications in photon detection and light harvesting, which motivates the quest for new approaches to improve the ...absorption in these systems. Here, we demonstrate a broadband and polarization-independent metal nanosquare arrays-dielectric-metal stucture to improve the light absorption in the solar cells based on bilayer of MoS
2
/graphene. By performing three-dimensional electromagnetic simulations, it is revealed that the optical absorption in the monolayer MoS
2
can be significantly enhanced to be over 60% in a broad wavelength range due to the combined effects of localized surface plasmonic resonance (LSPR), LSPR coupling and cavity resonance. Furthermore, the short current density of the bilayer solar cell reaches a high value of 15.7 mA/cm
2
, which is about 8.3 times that of the bilayer solar cell without the metal nanosquare arrays-dielectric-metal stucture structure. These results may provide useful guidance for future photovoltaics, energy conversion, and light harvesting devices.
This paper designed a kind of automatic conveying and stamping machine, which was mainly used for drawing thin sheet metal. UGNX software was used to design the motion law of the mechanism and the ...simulation mechanism. The time displacement diagram obtained by theoretical calculation and simulation was compared to verify the correctness of theoretical analysis and the rationality of the design. The comparison shows that the device meets the requirements of theoretical calculation. The device has the characteristics of simple structure, high efficiency and easy operation, which provides a reference for the subsequent realization of conveying and stamping devices with different requirements.
A large proportion of prokaryotic microbes in marine sediments remains uncultured, hindering our understanding of their ecological functions and metabolic features. Recent environmental metagenomic ...studies suggested that many of these uncultured microbes contribute to the degradation of organic matter, accompanied by acetogenesis, but the supporting experimental evidence is limited.
Estuarine sediments were incubated with different types of organic matters under anaerobic conditions, and the increase of uncultured bacterial populations was monitored. We found that (1) lignin stimulated the increase of uncultured bacteria within the class Dehalococcoidia. Their ability to metabolize lignin was further supported by the presence of genes associated with a nearly complete degradation pathway of phenolic monomers in the Dehalococcoidia metagenome-assembled genomes (MAGs). (2) The addition of cellulose stimulated the increase of bacteria in the phylum Ca. Fermentibacterota and family Fibrobacterales, a high copy number of genes encoding extracellular endoglucanase or/and 1,4-beta-cellobiosidase for cellulose decomposition and multiple sugar transporters were present in their MAGs. (3) Uncultured lineages in the order Bacteroidales and the family Leptospiraceae were enriched by the addition of casein and oleic acid, respectively, a high copy number of genes encoding extracellular peptidases, and the complete β-oxidation pathway were found in those MAGs of Bacteroidales and Leptospiraceae, respectively. (4) The growth of unclassified bacteria of the order Clostridiales was found after the addition of both casein and cellulose. Their MAGs contained multiple copies of genes for extracellular peptidases and endoglucanase. Additionally,
C-labeled acetate was produced in the incubations when
C-labeled dissolved inorganic carbon was provided.
Our results provide new insights into the roles of microorganisms during organic carbon degradation in anaerobic estuarine sediments and suggest that these macro and single molecular organic carbons support the persistence and increase of uncultivated bacteria. Acetogenesis is an additional important microbial process alongside organic carbon degradation. Video Abstract.
Semitransparent organic solar cells (ST-OSCs) based on the gasochromism of WO3 are theoretically proposed by capping a WO3 and a Pt layer on the transparent Ag electrode of the devices. Transfer ...matrix method is used to investigate the effects of the gaschromism of the WO3 layer on the transmission, short-circuit current density (Jsc), and color of the devices. It is revealed that the gaschromism can reduce the average transmission of the device from 33.4 % to 21.5% and a reduction of 35.6% is achieved for the ST-OSC with a 270nm-thick WO3 layer. This occurs because the gaschromism can change the reflection of Ag/WO3/Pt multilayer and improve light absorption in the WO3 layer. The superposed effects of these two factors lead to reduction in light transmission of the device. Meanwhile, the effects of the gaschromism on the Jsc and color coordinates of the devices are relatively small.
Members of the archaeal phylum Bathyarchaeota are among the most abundant microorganisms on Earth. Although versatile metabolic capabilities such as acetogenesis, methanogenesis, and fermentation ...have been suggested for bathyarchaeotal members, no direct confirmation of these metabolic functions has been achieved through growth of Bathyarchaeota in the laboratory. Here we demonstrate, on the basis of gene-copy numbers and probing of archaeal lipids, the growth of Bathyarchaeota subgroup Bathy-8 in enrichments of estuarine sediments with the biopolymer lignin. Other organic substrates (casein, oleic acid, cellulose, and phenol) did not significantly stimulate growth of Bathyarchaeota. Meanwhile, putative bathyarchaeotal tetraether lipids incorporated 13C from 13C-bicarbonate only when added in concert with lignin. Our results are consistent with organoautotrophic growth of a bathyarchaeotal group with lignin as an energy source and bicarbonate as a carbon source and shed light into the cycling of one of Earth’s most abundant biopolymers in anoxic marine sediment.
Methane is a potent greenhouse gas. Continental margins contain large reservoirs of methane as solid gas hydrate and the dissolved and gaseous forms of methane. Submarine methane seeps along the ...global continental margins, including the coastal seas, have been estimated to contribute 0.01 to 0.05 Gt of carbon to the atmosphere annually, accounting for between 1% and 5% of the global methane emissions to the atmosphere. Much of this methane is exhausted via microbial anaerobic methane oxidation. Methane biotransformation in the ocean has effects on global climate change. This review mainly introduces the mechanisms of methanogenesis and methane oxidation and describes new findings that will provide information that will improve the understanding of the balance in terms of the generation, migration and consumption of methane in marine environments. Moreover, this review provides new insights into methane biogeochemical cycles and the effects of marine methane budgets on global climate.
Bathyarchaeota is believed to play a crucial role in the global carbon cycle due to its vast biomass, broad distribution, and diverse habitat. However, its physiological and metabolic features are ...hard to determine without pure culture. While metagenomic analyses have shown that Bathyarchaeota has a complete inorganic carbon fixation (Wood-Ljungdahl, WL) pathway, no direct functional confirmation has been reported. To explore the inorganic carbon fixation ability of Bathyarchaeota, we used lignin and sodium bicarbonate-
13
C (NaH
13
CO
3
) in the long-term incubation of marine sediment samples. We found that Bathyarchaeota grew continuously in the cultivation system with lignin, and its abundance increased up to 15.3 times after 10 months, increasing its fraction of all archaea from 30% to 80%. We monitored the
δ
13
C of total organic carbon to identify microbial carbon fixation in the cultivation systems, finding that it increased in the first month while NaH
13
CO
3
was present but only increased continuously afterward when lignin was also present. Furthermore, ultracentrifugation was performed on DNA extracted from samples at different cultivation stages to separate DNA of different buoyant densities, and bathyarchaeotal and bacterial 16S ribosomal RNA (rRNA) gene abundance were quantified using qPCR. Compared to bacteria, bathyarchaeotal 16S rRNA tended to be concentrated in heavy layers after 4 months of incubation with lignin and NaH
13
CO
3
, indicating that Bathyarchaeota DNA contained
13
C through proliferation based on lignin utilization and NaH
13
CO
3
assimilation, proving the carbon fixation capacity of Bathyarchaeota.
Hot electron photodetectors based on a planar structure of metal-insulator /semiconductor-metal (MIM/MSM) have attracted much attention due to the easy and cheap fabrication process and the ...possibility of detecting light with energy lower than the semiconductor band gap. For this type of device, however, hot electron photocurrent is restricted by the trade-off between the light absorption and the internal quantum efficiency (IQE) since high absorption usually occurs within thick metals and the IQE in this case is usually low. The trade-off is circumvented in this paper by proposing a new type of hot electron photodetector based on planar MIM structure and coupled dual Tamm plasmons (TPs), which has a structure of one-dimensional photonic crystals (1DPCs)/Au/TiO
2
/Au/1DPCs. The coupled modes of the dual TPs at the two 1DPCs/Au interfaces can lead to a high absorption of 98% in a 5 nm-thick Au layer. As a result, the responsivity of the conventional device with two Schottky junctions in series configuration reaches a high value of 9.78 mA/W at the wavelength of 800 nm. To further improve the device performance, devices with four Schottky junctions in parallel configuration are proposed to circumvent the hot electrons loss at the interface of the Au layer and the first TiO
2
layer of the 1DPCs. Correspondingly, the hot electrons photocurrent doubles and reaches a higher value of 21.87 mA/W. Moreover, the bandwidth of the responsivity is less than 0.4 nm, the narrowest one when compared with that for the hot electron photodetectors reported so far in the published papers.
Microcavity is an efficient approach to manufacture colorful semitransparent organic solar cells (ST-OSCs) with high color purity by tailoring the transmission spectrum to narrow peaks. However, in ...this type of colorful semitransparent devices, high power conversion efficiency (PCE) and high peak transmittance are not yet simultaneously achieved. This paper proposes a new type of microcavity structure to achieve colorful ST-OSCs with both high PCE and high peak transmittance, in which a hybrid Au/Ag electrode is used as a mirror and WO3 is used as a spacer layer. First, it is demonstrated that the hybrid Au/Ag electrode mirror brings about an improvement of 7.7 and 5.5% for PCE and peak transmittance, respectively, when compared with those of the reference devices using the Ag electrode mirror. Specifically, the PCE of the optimized devices reaches the satisfactory value of over 9%, and the peak transmittance is over 25%. This value of PCE is the highest one reported so far for the microcavity-based ST-OSCs with the same peak transmittance. Second, it is demonstrated that the second-order resonance of the microcavity can be used to improve the color purity of green ST-OSCs by narrowing the transmission peak, and the combination of the second-order and third-order resonance can be used to construct colorful ST-OSCs with mixed colors. Thus, a novel approach is developed to tune the color of ST-OSCs, which is based on high-order resonance modes of the microcavity.
Semitransparent microcavity is constructed by sandwiching an active layer between the WO3/Ag/WO3 multilayer electrode and the thin Ag electrode capped by one-dimensional photonic crystals (1DPCs) to ...simultaneously improve light absorption and transmission of the semitransparent organic solar cells (OSCs). Optical simulations demonstrate that the upper limit to power conversion efficiency (PCEmax) of the semitransparent OSCs is improved up to 8.37%, an improvement of 14.0% from that of the conventional device without the microcavity; simultaneously, the transparency of the device reaches a relatively high value of 21.7% with an improvement of 8.0%. In addition, it is revealed that PCEmax, transparency and see-through color of the devices bear strong relevance to the photonic bandgap of 1DPCs. Transparency for the semitransparent OSCs can be tuned from 2.4% to 33% and the see-through color of the semitransparent OSCs can be tuned in a broad range by tailoring the center wavelength of the photonic bandgap. Results from the paper demonstrate the semitransparent microcavity is an efficient light trapping structure for semitransparent OSCs and can find application in the design and fabrication of semitransparent OSCs with high efficiency and high transparency.
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