40 research outputs found
Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide.
Conversion of carbon monoxide to high value-added ethylene with high selectivity by traditional syngas conversion process is challenging because of the limitation of Anderson-Schulz-Flory distribution. Herein we report a direct electrocatalytic process for highly selective ethylene production from CO reduction with water over Cu catalysts at room temperature and ambient pressure. An unprecedented 52.7 % Faradaic efficiency of ethylene formation is achieved through optimization of cathode structure to facilitate CO diffusion at the surface of the electrode and Cu catalysts to enhance the C-C bond coupling. The highly selective ethylene production is almost without other carbon-based byproducts (e.g. C1 -C4 hydrocarbons and CO2 ) and avoids the drawbacks of the traditional Fischer-Tropsch process that always delivers undesired products. This study provides a new and promising strategy for highly selective production of ethylene from the abundant industrial CO
The functional head of the Cambrian radiodontan (stem-group Euarthropoda) Amplectobelua symbrachiata
© The Author(s). 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article
A Cambrian crown annelid reconciles phylogenomics and the fossil record
Annelids are among the most disparate animal phyla, encompassing ambush predators, suspension feeders and terrestrial earthworms1. Early annelid evolution remains obscure or controversial2,3 , partly due to discordance between molecular phylogenies and fossils2,4. Cambrian annelid fossils have morphologies indicating epibenthic lifestyles, whereas phylogenomics recovers sessile, infaunal and tubicolous taxa as an early diverging grade5. Magelonidae and Oweniidae (Palaeoannelida1 28) are the sister group of all other annelids but contrast with Cambrian taxa in both lifestyle and gross
morphology2,6. We describe a new fossil polychaete, Dannychaeta tucolus, from the early Cambrian Canglangpu Formation7, preserved within delicate, originally organic dwelling tubes. The head has a well-defined spade-shaped prostomium with elongate ventrolateral palps. The body has a wide, stout thorax and elongate abdomen with biramous parapodia with parapodial lamellae. This character combination is shared with extant Magelonidae, and phylogenetic analyses recover Dannychaeta within Palaeoannelida. Dannychaeta is the oldest polychaete unambiguously belonging inside crown annelids, providing a constraint on the tempo of annelid evolution and revealing unrecognised ecological and morphological diversity in ancient annelids
A chancelloriid-like metazoan from the early Cambrian Chengjiang Lagerstätte, China
Nidelric pugio gen. et sp. nov. from the Cambrian Series 2 Heilinpu Formation, Chengjiang Lagerstätte, Yunnan Province, China, is an ovoid, sac-like metazoan that bears single-element spines on its surface. N. pugio shows no trace of a gut, coelom, anterior differentiation, appendages, or internal organs that would suggest a bilateral body plan. Instead, the sac-like morphology invites comparison with the radially symmetrical chancelloriids. However, the single-element spines of N. pugio are atypical of the complex multi-element spine rosettes borne by most chancelloriids and N. pugio may signal the ancestral chancelloriid state, in which the spines had not yet fused. Alternatively, N. pugio may represent a group of radial metazoans that are discrete from chancelloriids. Whatever its precise phylogenetic position, N. pugio expands the known disparity of Cambrian scleritome-bearing animals, and provides a new model for reconstructing scleritomes from isolated microfossils
A chancellorid-like metazoan from the early Cambrian Chengjiang Lagersttäte, China
Nidelric pugio gen. et sp. nov. from the Cambrian Series 2 Heilinpu Formation, Chengjiang Lagerstatte, Yunnan Province, China, is an ovoid, sac-like metazoan that bears single-element spines on its surface. N. pugio shows no trace of a gut, coelom, anterior differentiation, appendages, or internal organs that would
suggest a bilateral body plan. Instead, the sac-like morphology invites comparison with the radially symmetrical chancelloriids. However, the single-element spines of N. pugio are atypical of the complex multi-element spine rosettes borne by most chancelloriids and N. pugio may signal the ancestral chancelloriid state, in which the spines had not yet fused. Alternatively, N. pugio may represent a group of radial metazoans that are discrete from chancelloriids. Whatever its precise phylogenetic position, N. pugio expands the known disparity of Cambrian scleritome-bearing animals, and provides a new model for reconstructing scleritomes from isolated microfossils
A chancelloriid-like metazoan from the early Cambrian Chengjiang Lagerstätte, China
Nidelric pugiogen. et sp. nov.
from the Cambrian
Series 2 Heilinpu Formation,
Chengjiang Lagerstätte, Yunnan Province, China,
is an ovoid, sac-like metazoan that
bears
single-element
spines
on its surface.
N. pugio shows no trace of a gut, coelom,
anterior differentiation, appendages,
or internal organs that would suggest a bilateral
body plan. Instead,
the
sac-like
morphology
invites
comparison with
the radially
symmetrical
chancelloriids. However, the
single-element spines of
N. pugio
are
atypical
of the
complex multi-element spine
rosettes
borne by
most
chancelloriids
and
N. pugio
may signal the ancestral chancelloriid state, in which the spines had not yet fused.
Alternatively,
N. pugio
may represent a group of
radial
metazoans that are discrete
from
chancelloriids.
Whatever its precise phylogenetic position,
N. pugio
expands the
known disparity of Cambrian scleritome-bearing animals, and provides a new model
for reconstructing scleritomes from isolated microfossils