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It is commonly recognized that in radio frequency capacitive discharges, a higher excitation frequency can yield an enhanced electron heating rate and ion flux. Here, we reveal the low-frequency dependence of the plasma density and ion energy/angular distribution in a low-pressure (2 Pa), dual-frequency (DF) capacitively coupled argon plasma based on a combination of experiments and kinetic particle simulations. As the low frequency (LF, f L ) is decreased from 6.8 MHz to 40 kHz, the plasma density undergoes a moderate decline initially, followed by an increase, reaching a maximum at f L = 400 kHz. The enhanced plasma density is attributed to a combined effect of (i) an attenuated modulation effect of the LF source on the high-frequency electron heating and (ii) enhanced emission of electron-induced secondary electrons. At a lower f L , the ion transit time across the sheath, τ ion , gets comparable to or shorter than the LF period, τ LF , resulting in a higher ion energy with a narrower angular spread. The enhanced ion flux and ion energy in DF discharges operated at low frequencies in the range of hundreds of kHz are beneficial for the high-aspect-ratio plasma etching extensively used in the semiconductor industry. [ABSTRACT FROM AUTHOR]

Similarity laws (SLs) for low-pressure capacitive radio-frequency plasmas are generalized from one- to two-dimensional (2D) frameworks based on kinetic particle-in-cell simulations. Fundamental discharge parameters, such as the 2D distributions of electron densities and electric fields, are examined to assess the applicability of SLs to such discharges. The discharge characteristics are found to remain invariant when external control parameters are changed according to SLs. Even under conditions where nonlinear electron resonance heating caused by the self-excitation of the plasma series resonance due to the geometric reactor asymmetry plays an important role, the electron kinetics are shown to be invariant. Moreover, the validity of SLs for the ion dynamics is demonstrated. The results advance the applicability of SLs to a 2D cylindrical reactor geometry with azimuthal symmetry, indicating broad application prospects in practice. [ABSTRACT FROM AUTHOR]

Accurate quantum chemical studies at the CCSD(T)/CBS//CCSD/cc-pVTZ level predicted the depletion reaction of C3O by both singlet and triplet O-atoms to be barrierless, leading to the astrophysically very abundant CO plus triplet CCO. The barrierless nature of the reaction fully complied with the long conjecture, whereas the product differed significantly. Our kinetic calculations indicated that the reaction possesses significant negative temperature effect below 30 K. The calculations should be useful for understanding the astrophysical recycling for both the carbon and oxygen species. [ABSTRACT FROM AUTHOR]

Summary: Changes in carbohydrates and organic acids largely determine the palatability of edible tissues of horticulture crops. Elucidating the potential molecular mechanisms involved in the change in carbohydrates and organic acids, and their temporal and spatial crosstalk are key steps in understanding fruit developmental processes. Here, we used apple (Malus domestica Borkh.) as research materials and found that MdbHLH3, a basic helix–loop–helix transcription factor (bHLH TF), modulates the accumulation of malate and carbohydrates. Biochemical analyses demonstrated that MdbHLH3 directly binds to the promoter of MdcyMDH that encodes an apple cytosolic NAD‐dependent malate dehydrogenase, activating its transcriptional expression, thereby promoting malate accumulation in apple fruits. Additionally, MdbHLH3 overexpression increased the photosynthetic capacity and carbohydrate levels in apple leaves and also enhanced the carbohydrate accumulation in fruits by adjusting carbohydrate allocation from sources to sinks. Overall, our findings provide new insights into the mechanism of how the bHLH TF MdbHLH3 modulates the fruit quality. It directly regulates the expression of cytosolic malate dehydrogenase MdcyMDH to coordinate carbohydrate allocation and malate accumulation in apple. [ABSTRACT FROM AUTHOR]

Based on the seismic profiles, drilling, tomographic images and other geological data, we use the I2VIS code to program the Mesozoic finite‐difference numerical model in the southern part of the East China Sea Continental Shelf Basin (ECSCSB). We try to model the basin evolutionary process by setting up different boundaries to the 2‐D models. After analysing the simulation results of low‐speed and high‐speed stretching models, we found that under the condition of preliminary tensile value, the magma could not be generated in both rapid and slow stretching cases. This means that the regional extension of the Mesozoic ECSCSB is not the only dominant factor for basin evolution. Based on the analysis of the regional geological features and the modelling results, we suggest that the low‐velocity lithosphere mantle in the study area may be due to the melting of the mantle caused by the subduction and dehydration of the Izawa Nasaki Plate. The evolutionary process of the Mesozoic basins in the ECSCSB is closely related to regional extension and the magma upwelling caused by subduction and dehydration of the Izawa Nasaki Plate during the Mesozoic Era. The magma upwelling led to large‐scale magmatic events. It is likely to act in the Minjiang Sag, which resulted in the further rise of the Minjiang Sag and the formation of the present slope zone. [ABSTRACT FROM AUTHOR]

Key message: The divergence patterns of NBS - LRR genes in soybean Rsv3 locus were deciphered and several divergent alleles ( NBS_C, NBS_D and Columbia NBS_E ) were identified as the likely functional candidates of Rsv3. Abstract: The soybean Rsv3 locus, which confers resistance to the soybean mosaic virus (SMV), has been previously mapped to a region containing five nucleotide binding site-leucine-rich repeats ( NBS- LRR) genes (referred to as nbs_A- E) in Williams 82. In resistant cultivars, however, the number of NBS- LRR genes in this region and their divergence from susceptible alleles remain unclear. In the present study, we constructed and screened a bacterial artificial chromosome (BAC) library for an Rsv3-possessing cultivar, Zaoshu 18. Sequencing two positive BAC inserts on the Rsv3 locus revealed that Zaoshu 18 possesses the same gene content and order as Williams 82, but two of the NBS- LRR genes, NBS_C and NBS_D, exhibit distinct features that were not observed in the Williams 82 alleles. Obtaining these NBS-LRR genes from eight additional cultivars demonstrated that the NBS_A- D genes diverged into two different alleles: the nbs_A- D alleles were associated with the rsv3-type cultivars, whereas the NBS_A- D alleles were associated with the Rsv3-possessing cultivars. For the NBS_E gene, the cultivar Columbia possesses an allele ( NBS_E) that differed from that in Zaoshu 18 and rsv3-type cultivars ( nbs_E). Exchanged fragments were further detected on alleles of the NBS_C- E genes, suggesting that recombination is a major force responsible for allele divergence. Also, the LRR domains of the NBS_C- E genes exhibited extremely strong signals of positive selection. Overall, the divergence patterns of the NBS- LRR genes in Rsv3 locus elucidated by this study indicate that not only NBS_C but also NBS_D and Columbia NBS_E are likely functional alleles that confer resistance to SMV. [ABSTRACT FROM AUTHOR]

A small quantity of organic montmorillonite (OMMT) was introduced into an immiscible poly( l -lactide)/poly(ethylene vinyl acetate) (PLLA/EVA) blend. The selective location state of OMMT, the blend morphologies and the microstructure of the blend composites were systematically investigated. The theoretical calculation based on interfacial tensions and experimental observations showed that OMMT selectively located in the rigid PLLA component. Apparent morphological changes were observed for the blend composites. Rheological measurements showed that OMMT at relatively high content formed the percolated network structure in the blend composites. Tensile measurements showed that OMMT exhibited excellent reinforcement effect for the immiscible PLLA/EVA blends. Furthermore, tensile creep behavior measurements showed that incorporating OMMT into the immiscible PLLA/EVA blends facilitated the apparent enhancement of creep stability. The microstructure-performance relationship of the blend composites was then analyzed. [ABSTRACT FROM AUTHOR]