Doubly-substituted methane isotopologues (13CH3D and 12CH2D2) can provide unique information to resolve the origin, transport, and conversion of environmental methane. We used a high-resolution mass spectrometer (Thermo Fisher Scientific 253...

The chromophore 2,4,6‐tri(pyridyl‐4‐(3‐sulphonatopropyl))‐1,3,5‐triazine (TPST) was used in hydrogel electrochromic devices (ECDs). The hydrogel consists of TPST, K3[Fe(CN)6]/K4[Fe(CN)6] (K3) or 1,1’‐ferrocenedimethanol (FM), and sodium carboxymethyl cellulose. The devices showed dual‐band properties, K3‐TPST exhibiting absorption in NIR region at low voltage, while absorption of ECDs blue‐shifting at −2.8 V. ECDs changed from transparent to olive green to black with a coloration efficiency of >126.74 cm2/C at 850 nm and high cycling stability. The optical contrast of FM‐TPST ECD remains 79.3 % of the first cycle contrast after 2100 cycles. TPST can change its color from transparent to black at a high voltage of −2.2 V, with relatively short switching times (FM‐TPST, 5.3 s, and K3[Fe(CN)6]/K4[Fe(CN)6]‐TPST, 3.8 s). The response was accelerated up to 5 times by introducing a sulfonyl group with comparison to our previous work. The devices using TPST with sulfonyl moiety provide a new way for the fast‐response energy‐saving smart windows.

Methane (CH4) is a matter of environmental concern; however, global methane isotopologue data remain inadequate. This is due to the challenges posed by high-resolution testing technology and the need for larger sample volumes. Here, worldwide methane clumped isotope databases (n = 465) were compiled. We compared machine-learning (ML) models and used random forest (RF) to predict new Δ12CH2D2 distributions, which cover valuable and hard-to-replicate methane clumped isotope experimental data. Our RF model yields a reliable and continuous database including ruminants, acetoclastic methane, multiple pyrolysis, and controlled experiments. We showed the effectiveness of utilizing a new data set to quantify isotopologue fractionations in biogeochemical methane processes, as well as predicting the steady-state atmospheric methane clumped isotope composition (Δ13CH3D of +2.26 ± 0.71‰ and Δ12CH2D2 of +62.06 ± 4.42‰) with notable biological contributions. Our measured summer and winter water emitted gases (n = 6) demonstrated temperature-driven seasonal microbial community evolution determined by atmospheric clumped isotope temporal variations (Δ 13CH3D ∼ −0.91 ± 0.25 ‰ and Δ12CH2D2 ∼ +3.86 ± 0.84 ‰), which in turn is relevant for future models quantifying the contribution of methane sources and sinks. Predicting clumped isotopologues translates our methane geochemical understanding into quantifiable variables for modeling that can continue to improve predictions and potentially inform global greenhouse gas emissions and mitigation policy.

The electrochromic detection of latent fingermarks on polished or unpolished, flat or curved metal surfaces is described using electrochromic material, 1,1'dibenzyl-4,4'-bipyridinium dichloride. The surface area covered by fingermarks acts as an insulating mask, causing 1,1'-dibenzyl-4,4'-bipyridinium dichloride to change color and produce inversed images of the fingermark. By changing the applied potential, the optical properties of 1,1'-dibenzyl-4,4'-bipyridinium dichloride can be continuously and reversibly adjusted to optimize the visual contrast of fingermarks, so as to realize the detection of latent fingermarks on stainless steel surface. It is demonstrated that the fabricated electrochromic devices can detect the fingermarks on these types of surfaces within twenty seconds at À 1.0 ~À 2.0 V. This work can qualify as a tangible improvement in fingermark detection of the natural fingermarks on the never-cleaned (more than 3 years) and curved surfaces of daily-used container, e. g. cup, and the handle of cleaning tool, mop.