Na
(B
H
)
(B
H
)
, a new solid-state sodium electrolyte is shown to offer high Na
conductivity of 0.9 mS cm
at 20 °C, excellent thermal stability up to 300 °C, and a large electrochemical stability ...window of 3 V including stability towards sodium metal anodes, all essential prerequisites for a stable room-temperature 3 V all-solid-state sodium-ion battery.
The incorporation of aluminum in magnesium silicate hydrate (M-S-H) phases was investigated. Magnesium (alumino) silicate hydrate (M-(A-)S-H) with Mg/Si ratios equal to 1.1 or 1.7 and Al/Si ranging ...from 0 to 0.2 were synthetized in batch experiments and equilibrated at 20, 50 and 70 °C. pH values between 9 and 10.5 were observed and aluminum up to Al/Si ~0.15–0.18 was incorporated in M-(A-)S-H. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray pair distribution function (PDF) analysis, transmission electron microscopy (TEM), 29Si and 27Al MAS NMR data showed that the M-(A-)S-H phases formed were similar to M-S-H with limited coherent size and a comparable polymerization degree of the tetrahedral silicates. Aluminum was incorporated in both tetrahedral and octahedral sites of M-S-H, while no aluminum was present as exchangeable cation on the surface sites.
Water-redispersible, nanofibrillated cellulose (NFC) in powder form was prepared from refined, bleached beech pulp (RBP) by carboxymethylation (c) and mechanical disintegration (m). Two routes were ...examined by altering the sequence of the chemical and mechanical treatment, leading to four different products: RBP-m and RBP-mc (route 1), and RBP-c and RBP-cm (route 2). The occurrence of the carboxymethylation reaction was confirmed by FT-IR spectrometry and ¹³C solid state NMR (¹³C CP-MAS) spectroscopy with the appearance of characteristic signals for the carboxylate group at 1,595 cm⁻¹ and 180 ppm, respectively. The chemical modification reduced the crystallinity of the products, especially for those of route 2, as shown by XRD experiments. Also, TGA showed a decrease in the thermal stability of the carboxymethylated products. However, sedimentation tests revealed that carboxymethylation was critical to obtain water-redispersible powders: the products of route 2 were easier to redisperse in water and their aqueous suspensions were more stable and transparent than those from route 1. SEM images of freeze-dried suspensions from redispersed RBP powders confirmed that carboxymethylation prevented irreversible agglomeration of cellulose fibrils during drying. These results suggest that carboxymethylated and mechanically disintegrated RBP in dry form is a very attractive alternative to conventional NFC aqueous suspensions as starting material for derivatization and compounding with (bio)polymers.
This communication presents the first synthesis of nanoconfined Lithium closo-borate, Li2B12H12, using nanoporous SiO2 as scaffold. The yield of Li2B12H12 is up to 94 mol%. The as-synthesized ...nanoconfined Li2B12H12 exhibits a structural transition around 380 °C and conversion to H-deficiency Li2B12H12-x at 580 °C.
Ca(BH
4
)
2
could reversibly store 9.6 wt% hydrogen based on the overall reaction of Ca(BH
4
)
2
→ 1/3CaB
6
+ 2/3CaH
2
+ 10/3H
2
. Formation of CaB
6
instead of elemental boron and/or high boranes (
...e.g.
CaB
12
H
12
) in the dehydrogenation process is crucial for rehydrogenation. Here, we reported two experimental protocols regarding how to form CaB
6
from the decomposition of Ca(BH
4
)
2
: (1) decomposition below the melting point,
e.g.
350 °C
via
CaB
2
H
6
to CaB
6
and (2) decomposition above the melting point,
e.g.
400 °C
via
elemental boron to CaB
6
.
The formation of CaB
6
from the thermal decomposition of Ca(BH
4
)
2
goes along two distinct routes,
i.e. via
CaB
2
H
6
or elemental boron as a reaction intermediate, depending on temperature.
We assess relationships among 192 species in all 12 monocot orders and 72 of 77 families, using 602 conserved single-copy (CSC) genes and 1375 benchmarking single-copy ortholog (BUSCO) genes ...extracted from genomic and transcriptomic datasets. Phylogenomic inferences based on these data, using both coalescent-based and supermatrix analyses, are largely congruent with the most comprehensive plastome-based analysis, and nuclear-gene phylogenomic analyses with less comprehensive taxon sampling. The strongest discordance between the plastome and nuclear gene analyses is the monophyly of a clade comprising Asparagales and Liliales in our nuclear gene analyses, versus the placement of Asparagales and Liliales as successive sister clades to the commelinids in the plastome tree. Within orders, around six of 72 families shifted positions relative to the recent plastome analysis, but four of these involve poorly supported inferred relationships in the plastome-based tree. In Poales, the nuclear data place a clade comprising Ecdeiocoleaceae+Joinvilleaceae as sister to the grasses (Poaceae); Typhaceae, (rather than Bromeliaceae) are resolved as sister to all other Poales. In Commelinales, nuclear data place Philydraceae sister to all other families rather than to a clade comprising Haemodoraceae+Pontederiaceae as seen in the plastome tree. In Liliales, nuclear data place Liliaceae sister to Smilacaceae, and Melanthiaceae are placed sister to all other Liliales except Campynemataceae. Finally, in Alismatales, nuclear data strongly place Tofieldiaceae, rather than Araceae, as sister to all the other families, providing an alternative resolution of what has been the most problematic node to resolve using plastid data, outside of those involving achlorophyllous mycoheterotrophs. As seen in numerous prior studies, the placement of orders Acorales and Alismatales as successive sister lineages to all other extant monocots. Only 21.2% of BUSCO genes were demonstrably single-copy, yet phylogenomic inferences based on BUSCO and CSC genes did not differ, and overall functional annotations of the two sets were very similar. Our analyses also reveal significant gene tree-species tree discordance despite high support values, as expected given incomplete lineage sorting (ILS) related to rapid diversification. Our study advances understanding of monocot relationships and the robustness of phylogenetic inferences based on large numbers of nuclear single-copy genes that can be obtained from transcriptomes and genomes.
The chemical aging with phosphorous causes both severe physical and chemical modifications in the catalyst, while thermal aging leads to mere physical alterations. Thus, chemical aging is more ...detrimental than thermal aging for three-way catalytic efficiency. Display omitted
► Thermal aging in air at 700°C causes mere physical modifications in PdOx/Al2O3. ► Chemical aging with phosphorous leads to severe physical and chemical alterations. ► Chemical aging decreases the reducibility of PdOx species. ► Chemical aging diminishes both oxidation and reduction efficiency of the catalyst. ► Thermal aging essentially affects the oxidation efficiency of the catalyst.
Thermal and chemical aging induced physical and chemical modifications in the model three-way catalyst Pd/Al2O3 for compressed natural gas vehicles exhaust were studied. The fresh catalyst Pd/Al/F (calcined at 500°C for 4h) was subjected to either thermal (Pd/Al/700) or chemical (poisoned with phosphorous (P), XP/Pd/Al; X=1.8 or 7.5wt%) aging under air flow at 700°C for 5h. The catalysts were analyzed by N2-physisorption, CO-chemisorption, high angular annular dark-field scanning transmission electron microscopic (HAADF-STEM), X-ray diffraction (XRD), solid state 31P MAS NMR, H2-temperature programmed reduction (H2-TPR) and in situ X-ray absorption near edge structure spectroscopy (XANES) during H2-TPR. Characterization results reveal that thermal aging leads to merely physical modifications such as decreased surface area of the support and palladium (Pd) dispersion in Pd/Al/700. Whereas, chemical aging causes both severe physical and chemical modifications in XP/Pd/Al: (i) physical modifications are clogging of support pores and fouling of Pd nanoparticles with P as evident from N2-physisorption, CO-chemisorption and HAADF-STEM and (ii) chemical alterations are the conversion of support aluminum oxide into aluminum phosphate as evident from solid state 31P MAS NMR, and decreased reducibility of PdOx species as evident from H2-TPR and in situ XANES. Consequently, chemical aging is more detrimental than thermal aging for three-way catalytic (TWC) performance as evident from the activity data. Undoubtedly, P (chemical aging) profoundly decreases the TWC efficiency. On the other hand, mere thermal aging considerably decreases CO and CH4 oxidation efficiency, but interestingly improves the NO reduction efficiency.
A 49-year old man was found dead at home next to a glass containing a dried, white, crystalline substance and near a bag containing pills with the imprint XANAX, the trade name of alprazolam. A ...comprehensive screening of material collected during the autopsy revealed the presence of etizolam and caffeine in lethal concentrations (0.77 μg/mL and 190 μg/mL) but no trace of alprazolam. Benzodiazepine analogue etizolam is rarely prescribed in Germany, and as a result there are not many reports about fatal cases. It has anxiolytic, hypnotic, sedative and muscle-relaxant properties and is used for the short-term treatment of anxiety and panic attacks. The purine alkaloid caffeine, conversely, is the most widely used central nervous system stimulant. The following report outlines potentially the first reported case of a lethal combination of the downer etizolam and the upper caffeine in medical literature.
The iconic giraffe, an ecologically important browser, has shown a substantial decline in numbers across Africa since the 1990s. In Serengeti National Park, Tanzania, giraffes reached densities of ...1.5–2.6 individuals km⁻² in the 1970s coincident with a pulse of Acacia tree recruitment. However, despite continued increases in woody cover between the 1980s and the 2000s, giraffe recruitment and survival rates have declined and density has dropped to only 0.3–0.4 giraffes km⁻². We used a decision table to investigate how four extrinsic factors may have contributed to these declines: food supply, predation, parasites, and poaching, which have all been previously shown to limit Serengeti ungulate populations. Lower recruitment likely resulted from a reduction in diet quality, owing to the replacement of preferred trees with unpalatable species, while decreased adult survival resulted from illegal harvesting, which appears to have had a greater impact on giraffe populations bordering the western and northern Serengeti. The Serengeti giraffe population will likely persist at low-to-moderate densities until palatable tree species regain their former abundance. Leslie matrix models suggest that park managers should meanwhile redouble their efforts to reduce poaching, thereby improving adult survival.
This communication presents the first synthesis of nanoconfined Lithium closo-borate, Li
B
H
, using nanoporous SiO
as scaffold. The yield of Li
B
H
is up to 94 mol%. The as-synthesized nanoconfined ...Li
B
H
exhibits a structural transition around 380 °C and conversion to H-deficiency Li
B
H
at 580 °C.
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