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Homosporous lycophytes (Lycopodiaceae) are a deeply diverged lineage in the plant tree of life, having split from heterosporous lycophytes (Selaginella and Isoetes) ~400 Mya. Compared to the heterosporous lineage, Lycopodiaceae has markedly larger genome sizes and remains the last major plant clade for which no chromosome-level assembly has been available. Here, we present chromosomal genome assemblies for two homosporous lycophyte species, the allotetraploid Huperzia asiatica and the diploid Diphasiastrum complanatum. Remarkably, despite that the two species diverged ~350 Mya, around 30% of the genes are still in syntenic blocks. Furthermore, both genomes had undergone independent whole genome duplications, and the resulting intragenomic syntenies have likewise been preserved relatively well. Such slow genome evolution over deep time is in stark contrast to heterosporous lycophytes and is correlated with a decelerated rate of nucleotide substitution. Together, the genomes of H. asiatica and D. complanatum not only fill a crucial gap in the plant genomic landscape but also highlight a potentially meaningful genomic contrast between homosporous and heterosporous species.

SUMMARY: Acacetin, a flavonoid compound, possesses a wide range of pharmacological effects, including antimicrobial, immune regulation, and anticancer effects. Some key steps in its biosynthetic pathway were largely unknown in flowering plants. Here, we present the first haplotype‐resolved genome of Chrysanthemum indicum, whose dried flowers contain abundant flavonoids and have been utilized as traditional Chinese medicine. Various phylogenetic analyses revealed almost equal proportion of three tree topologies among three Chrysanthemum species (C. indicum, C. nankingense, and C. lavandulifolium), indicating that frequent gene flow among Chrysanthemum species or incomplete lineage sorting due to rapid speciation might contribute to conflict topologies. The expanded gene families in C. indicum were associated with oxidative functions. Through comprehensive candidate gene screening, we identified five flavonoid O‐methyltransferase (FOMT) candidates, which were highly expressed in flowers and whose expressional levels were significantly correlated with the content of acacetin. Further experiments validated two FOMTs (CI02A009970 and CI03A006662) were capable of catalyzing the conversion of apigenin into acacetin, and these two genes are possibly responsible acacetin accumulation in disc florets and young leaves, respectively. Furthermore, combined analyses of ancestral chromosome reconstruction and phylogenetic trees revealed the distinct evolutionary fates of the two validated FOMT genes. Our study provides new insights into the biosynthetic pathway of flavonoid compounds in the Asteraceae family and offers a model for tracing the origin and evolutionary routes of single genes. These findings will facilitate in vitro biosynthetic production of flavonoid compounds through cellular and metabolic engineering and expedite molecular breeding of C. indicum cultivars. [ABSTRACT FROM AUTHOR]

Summary: Metal oxide semiconductor field effect transistors (MOSFETs) are widely used in various power electronic systems, and the establishment of the electromagnetic compatibility (EMC) model for MOSFETs is crucial for EMC analysis of these systems, especially high‐frequency switching circuits. In this paper, a MOSFET EMC modeling method is proposed based on electrical characteristic measurement, simplex optimization, and particle swarm optimization (PSO), to make MOSFET models meet both functionality and EMC analysis requirements. First, systematic methods for extracting SPICE parameters based on physical MOSFETs are presented, including a proposed curve‐fitting method based on PSO for extracting the CDS‐VDS and ID‐VGS characteristic parameters. Second, parametric influence analyses are conducted on some important model parameters, and the law that these parameters affect the EMC of MOSFETs is obtained. Finally, the preliminary MOSFET model was optimized comprehensively using the simplex method. The measured and simulated results are in good agreement in both time domain and frequency domain. It proves that the established model meets the requirements for model accuracy in terms of both EMC and functionality. Therefore, the proposed EMC modeling method is feasible. [ABSTRACT FROM AUTHOR]

Summary: Printed circuit boards play an increasingly important role in modern electronic systems. Equivalent dipole moments are widely used to reconstruct the radiated fields of printed circuit boards in view of the extremely high complexity. In this paper, an improved source reconstruction method based on complex‐valued neural network is proposed to investigate the radiation properties of printed circuit boards working in microwave frequency band. Firstly, the magnetic field data obtained from the near‐field scanning are utilized to construct a matrix equation based on the source reconstruction theory. Secondly, the kernel of the complex‐valued neural network is constructed through the algorithm of complex numbers, which eventually end up with the novel neural network with the help of the principle of regression optimization. Thirdly, the data obtained from the near‐field scanning are fed into the neural network for effective training to get the equivalent dipole model. Finally, several numerical examples and available measurement results are given to validate the method. Compared with the commonly used Tikhonov regularization method, the proposed method possesses higher accuracy and better robustness in noise suppression. [ABSTRACT FROM AUTHOR]

Summary: Bipolar junction transistors (BJTs) are widely used in various electronic systems, and the establishment of the electromagnetic compatibility (EMC) model for BJTs is crucial for EMC analysis of these systems, such as high‐frequency circuits. In this paper, a BJT EMC model that satisfies both functionality and EMC analysis requirements was established based on physical characteristic measurement. First, comprehensive and systematic methods for measurement and extracting SPICE parameters based on physical BJTs are presented, including a proposed curve‐fitting calculation method for extracting barrier capacitance parameters. Second, an analysis of the impact of major BJT electrical characteristics parameters was conducted, leading to the identification of important model parameters affecting BJT functionality and EMC. Finally, the primary BJT model was optimized using the simplex method, and a method for EMC analysis and verification of the BJT model was presented. The experimental and simulation results are in good agreement, and the established model meets the accuracy requirements for both EMC and functionality. Therefore, the proposed method is feasible and suitable for the EMC modeling of BJTs. [ABSTRACT FROM AUTHOR]

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Stipa shanxiensis, a cryptic species within Stipa grandis that originated from central and western China, is described based on morphological, genomic, and ecological data from field and common garden experiments. Stipa shanxiensis morphologically resembles S. grandis, although phylogenetically it is closely related to the less morphologically similar Stipa baicalensis and Stipa krylovii. Of the eight significant morphological differences between S. shanxiensis and S. grandis, the two, cauline ligules longer than 2 cm with a filiform apex, and hairs shorter than 0.2 mm on the adaxial surface of the cauline uppermost leaves can be used to distinguish the species. Results from a common garden experiment verified that the two diagnostic characteristics were relatively stable and less morphologically plastic in response to environmental variation. Furthermore, a significant ecological divergence was found between S. shanxiensis and S. grandis, such that the former preferred warmer and more humid climates, and their predicted distribution was generally separated. Taken together, our results highlight that the integrative taxonomic approach was valuable for recognizing a new cryptic species in Stipa. In particular, we find that common garden experiments involving the effects of growth stage and characteristic position helped to morphologically diagnose cryptic species. These findings may also facilitate our understandings of ecological adaption and phenotypic plasticity in response to environmental change. [ABSTRACT FROM AUTHOR]

Tuning metal–support interactions (MSIs) to precisely control the selectivity of supported Cu catalysts toward the CO2 reduction reaction (CO2RR) is a crucial yet challenging topic. Herein, a series of CuO nanosheet/CeO2 nanorod composites with various morphologies and compositions were synthesized and used as electrocatalysts. The CO2RR product distributions of composites are experimentally verified to be dependent on the loading amounts and sizes of CuO nanosheets, with the maximum Faradaic efficiency (FE) of CH4 and C2H4 reaching 37.8 and 44.8%, respectively. The mechanism investigation supports our perspective that modulating the strength of the MSIs between CuO nanosheets and CeO2 nanorods not only influences the adsorption properties of CO2RR intermediates but also further dominates the formation of exposed facets during the CuO structural reconstruction process, thus customizing the CO2RR pathway. [ABSTRACT FROM AUTHOR]

We investigated the size distribution of 137Cs in soils in the vicinity of the Qinshan nuclear power plant. The soil samples were separated into five fractions, namely coarse sand (2000–250 μm), fine sand (250–53 μm), silt (53–20 μm and 20–2 μm), and clay (< 2 μm). The results show that 137Cs was concentrated in the clay and silt fractions. X-ray diffraction analysis of size-fractionated samples showed that micaceous minerals such as chlorite and muscovite are critical in the fixation of 137Cs in the soil. No significant relationship was observed between 137Cs concentrations and organic carbon content in the soil. [ABSTRACT FROM AUTHOR]