A series
of donor–acceptor “”-shaped gridarenes
were synthesized with BT units as the crossbeam and thiophene units
as the π-bridge. The donor–acceptor gridization functional
effects on optoelectronic properties were then studied experimentally
and computationally to provide a platform to adjust the energetics
of the highest occupied molecular orbital/lowest unoccupied molecular
orbital levels. Finally, G-DTh-based two-terminal memristor
indium tin oxide/G-DTh:TBAPF6/Al successfully
realizes conventional learning processes, synaptic potentiation, and
depression plasticity which are essential for neuromorphic computation.
Mitochondrial genomes (mitogenomes) are important for understanding molecular evolution and phylogenetic relationships. The complete mitogenome of Perisesarma bidens was determined, which is 15,641 bp in length. The A + T content of P. bidens mitogenome was 74.81%. The AT skew was slightly negative (−0.021). The 22 tRNAs ranged from 65 to 73 bp and were highly A + T biased. All tRNA genes had typical cloverleaf structures, except for the trnS1 gene, which lacked a dihydrouridine (DHU) arm. The gene order within the P. bidens mitogenome was identical to the pancrustacean ground pattern, except for the translocation of the trnH. Additionally, the gene order of trnI-trnQ-trnM in pancrustacean ground pattern became trnQ-trnI-trnM in P. bidens. Phylogenetic analyses supported the inclusion of P. bidens in Sesarmidae and the promotion of Sesarminae to Sesarmidae. The results will help us to better understand the status and evolutionary history of Grapsoidea crabs.
To better understand the factors controlling the quartz luminescence sensitivity in loess deposits, samples from two loess sections in southern Tajikistan are investigated. Both pattern and amplitude in the variations of quartz luminescence sensitivity of these two sections are similar, showing higher values in pedocomplex units and lower values in the loess units. Similar trends of variation are found between the quartz luminescence sensitivity and climate proxies, including frequency-dependent magnetic susceptibility, median grain size and IRSL/[post-IR] OSL ratio. Laboratory experiments involving thermal activation and repeated bleaching/irradiation cycles reveal much larger sensitivity enhancement for samples with initial lower sensitivity from loess units than those from pedocomplex units with higher sensitivity. The observed systematic contrast in quartz luminescence sensitivity between the loess and pedocomplex units are interpreted as resulting from the differentiation of the weathering products from the source area and subsequent sensitization during the sedimentary transfer prior to deposition.
The blue king crab, Paralithodes platypus, which belongs to the family Lithodidae, is a commercially and ecologically important species. However, a high‐quality reference genome for the king crab has not yet been reported. Here, we assembled the first chromosome‐level blue king crab genome, which contains 104 chromosomes and an N50 length of 51.15 Mb. Furthermore, we determined that the large genome size can be attributed to the insertion of long interspersed nuclear elements and long tandem repeats. Genome assembly assessment showed that 96.54% of the assembled transcripts could be aligned to the assembled genome. Phylogenetic analysis showed the blue king crab to have a close relationship with the Eubrachyura crabs, from which it diverged 272.5 million years ago. Population history analyses indicated that the effective population of the blue king crab declined sharply and then gradually increased from the Cretaceous and Neogene periods, respectively. Furthermore, gene families related to developmental pathways, steroid and thyroid hormone synthesis, and inflammatory regulation were expanded in the genome, suggesting that these genes contributed substantially to the environmental adaptation and unique body plan evolution of the blue king crab. The high‐quality reference genome reported here provides a solid molecular basis for further study of the blue king crab's development and environmental adaptation.
The long-term variability of total, direct and diffuse solar radiation across China during 1958-2016 is investigated based on a ground-measured daily radiation dataset. Missing data are estimated using a 3-day average moving window and a backpropagation artificial neural network (BP network). The BP network achieves better estimates of direct (R 2 = 0.32-0.96) than diffuse radiation (R 2 = 0.00-0.81). A dimming period during 1958-1990 and a "From Dimming to Brightening" transition between 1990 and 1993 have been detected across China. The declining ratio of direct to diffuse radiation suggests a degrading air quality caused by increasing aerosols in eastern China. To study the aerosol effect on radiation, two empirical models are developed from 2000-2016 using the ground-measured total radiation, sunshine duration and satellite-retrieved total aerosol concentration. Both models perform well in the estimate of direct (R 2 = 0.71-0.89) and diffuse radiation (R 2 = 0.63-0.95). The increasing total radiation in eastern China since 2000 is mainly contributed by diffuse radiation. Besides, small anthropogenic aerosols can increase diffuse fraction, the proportion of diffuse in total radiation, whereas large natural aerosols may reduce it. The BP network and empirical models exhibit a better agreement in the estimate of direct than diffuse radiation in eastern China, which highlights the impact of aerosols on diffuse radiation in the recent decade.
K E Y W O R D S
The design and assembly of photoelectro‐active molecular channel structures is of great importance because of their advantages in charge mobility, photo‐induced electron transfer, proton conduction, and exciton transport. Herein, we report the use of racemic 9,9′‐diphenyl‐[2,2′‐bifluorene]‐9,9′‐diol (DPFOH) enantiomers to produce non‐helical 1D channel structures. Although the individual molecule does not present any molecular symmetry, two pairs of racemic DPFOH enantiomers can form a C2‐symmetric closed loop via the stereoscopic herringbone assembly. Thanks to the special symmetry derived from the enantiomer pairs, the multiple supramolecular interactions, and the padding from solvent molecules, this conventionally unstable topological structure is achieved. The etching of solvent in 1D channels leads to the formation of microtubes, which exhibit a significant lithium‐ion conductivity of 1.77×10−4 S cm, indicating the potential research value of this novel 1D channel structure.
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