Towards a reliable prediction of the infrared spectra of cosmic fullerenes and their derivatives in the JWST era

Fullerenes, including C60, C70, and C60+, are widespread in space through their characteristic infrared vibrational features (C60+ also reveals its presence in the interstellar medium through its electronic transitions) and offer great insights into the carbon chemistry and stellar evolution. The potential existence of fullerene-related species in space has long been speculated and recently put forward by a set of laboratory experiments of C60+, C60H+, C60O+, C60OH+, C70H+, and [C60-Metal]+ complexes. The advent of the James Webb Space Telescope (JWST) provides a unique opportunity to search for these fullerene-related species in space. To facilitate JWST search, analysis, and interpretation, an accurate knowledge of their vibrational properties is essential. Here, we compile a VibFullerene database and conduct a systematic theoretical study on those species. We derive a set of range-specific scaling factors for vibrational frequencies, to account for the deficiency of density functional theory calculations in predicting the accurate frequencies. Scaling factors with low root-mean-square and median errors for the frequencies are obtained, and their performance is evaluated, from which the best-performing methods are recommended for calculating the infrared spectra of fullerene derivatives which balance the accuracy and computational cost. Finally, the recommended vibrational frequencies and intensities of fullerene derivatives are presented for future JWST detection.Comment: 19 pages, 8 figures, 5 tables. Accepted for publication in MNRA

Observational Evidence for an Age Dependence of Halo Bias

We study the dependence of the cross-correlation between galaxies and galaxy groups on group properties. Confirming previous results, we find that the correlation strength is stronger for more massive groups, in good agreement with the expected mass dependence of halo bias. We also find, however, that for groups of the same mass, the correlation strength depends on the star formation rate (SFR) of the central galaxy: at fixed mass, the bias of galaxy groups decreases as the SFR of the central galaxy increases. We discuss these findings in light of the recent findings by Gao et al (2005) that halo bias depends on halo formation time, in that halos that assemble earlier are more strongly biased. We also discuss the implication for galaxy formation, and address a possible link to galaxy conformity, the observed correlation between the properties of satellite galaxies and those of their central galaxy.Comment: 4 pages, 4 figures, Accepted for publication in ApJ Letters. Figures 3 and 4 replaced. The bias dependence on the central galaxy luminosity is omitted due to its sensitivity to the mass mode

Evaluation of Biogas and Solar Energy Coupling on Phase-Change Energy-Storage Heating Systems: Optimization of Supply and Demand Coordination

Biogas heating plays a crucial role in the transition to clean energy and the mitigation of agricultural pollution. To address the issue of low biogas production during winter, the implementation of a multi-energy complementary system has become essential for ensuring heating stability. To guarantee the economy, stability, and energy-saving operation of the heating system, this study proposes coupling biogas and solar energy with a phase-change energy-storage heating system. The mathematical model of the heating system was developed, taking an office building in Xilin Hot, Inner Mongolia (43.96000° N, 116.03000° E) as a case study. Additionally, the Sparrow Search Algorithm (SSA) was employed to determine equipment selection and optimize the dynamic operation strategy, considering the minimum cost and the balance between the supply and demand of the building load. The operating economy was evaluated using metrics such as payback period, load ratio, and daily rate of return. The results demonstrate that the multi-energy complementary heating system, with a balanced supply and demand, yields significant economic benefits compared to the central heating system, with a payback period of 4.15 years and a daily return rate of 32.97% under the most unfavorable working conditions. Moreover, the development of a daily optimization strategy holds practical engineering significance, and the optimal scheduling of the multi-energy complementary system, with a balance of supply and demand, is realized

Probing regulon of ArcA in Shewanella oneidensis MR-1 by integrated genomic analyses

<p>Abstract</p> <p>Background</p> <p>The Arc two-component system is a global regulator controlling many genes involved in aerobic/anaerobic respiration and fermentative metabolism in <it>Escherichia coli</it>. <it>Shewanella oneidensis </it>MR-1 contains a gene encoding a putative ArcA homolog with ~81% amino acid sequence identity to the <it>E. coli </it>ArcA protein but not a full-length <it>arcB </it>gene.</p> <p>Results</p> <p>To understand the role of ArcA in <it>S. oneidensis</it>, an <it>arcA </it>deletion strain was constructed and subjected to both physiological characterization and microarray analysis. Compared to the wild-type MR-1, the mutant exhibited impaired aerobic growth and a defect in utilizing DMSO in the absence of O₂. Microarray analyses on cells grown aerobically and anaerobically on fumarate revealed that expression of 1009 genes was significantly affected (<it>p </it>< 0.05) by the mutation. In contrast to <it>E. coli </it>ArcA, the protein appears to be dispensable in regulation of the TCA cycle in <it>S. oneidensis</it>. To further determine genes regulated by the Arc system, an ArcA recognition weight matrix from DNA-binding data and bioinformatics analysis was generated and used to produce an ArcA sequence affinity map. By combining both techniques, we identified an ArcA regulon of at least 50 operons, of which only 6 were found to be directly controlled by ArcA in <it>E. coli</it>.</p> <p>Conclusion</p> <p>These results indicate that the Arc system in <it>S. oneidensis </it>differs from that in <it>E. coli </it>substantially in terms of its physiological function and regulon while their binding motif are strikingly similar.</p