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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 back-to-back connection of two three-to-single-phase matrix converters (MCs) through a high-frequency transformer to create the so called MC-based solid state transformer (SST) for interactive grid interfacing is proposed in this paper. The solution provides single-stage bidirectional ac–ac power conversion. There are advantages of no lifetime-limited storage capacitors, light weight, and compact volume. The conventional modulation methods of this MC-SST system require additional control design for power management. Besides, space vector modulation contains sophisticated voltage and current vectors computation and duty cycle composition, considering the two back-to-back connected three-to-single-phase MCs. In this paper, a model predictive control (MPC) is proposed for this MC-SST linking different ac grids. The proposed MPC predicts the state variables based on the discrete model of MC-SST system and the present circuit variables, and then selects an optimal switching state that ensures the smallest value of a cost function, for the next sampling time. Simulation and experimental studies are carried out to demonstrate effectiveness and simplicity of the proposed MPC for such MC-SST grid-interfacing system.

The existing single-phase, quasi-Z-source inverter (qZSI), photovoltaic (PV) power system with integrated battery energy storage (BES), abbreviated as BES-qZSI-PV power system, has several well-known advantages, but cannot operate at night because there is no PV power input. In this study, a solution to overcome this issue is proposed. First, the power circuit of the conventional BES-qZSI-PV topology is modified to allow its operation at both day and night. Then, the system model for the night-operation mode is built and a qZS network parameters’ design method to limit the double-line frequency harmonic at the dc side is developed. A control strategy to ensure the high-performance operation of the system at all times, is proposed. Based on an experimental platform of single-phase BES-qZSI-PV power system, three groups of experimental tests with different qZS network parameters and battery voltages are carried out to verify the model and parameters design method by means of comparing the experimental, circuit-based simulated, and model-based calculated results. The proposed BES-qZSI-PV system performance is experimentally evaluated in steady-state operation and day-to-night transit operation, as well as by the power efficiency curves in day- and night-modes.

A common mode voltage (CMV) reduction method is proposed for the active power filter (APF) integrated single-phase quasi-Z-source inverter (qZSI) based photovoltaic (PV) power system. The APF integrated qZSI completely compensates the dc-side double-line-frequency (2ω) ripple through the APF capacitor, while maintaining low qZS inductance and capacitance. The proposed method reduces the CMV amplitude to half of that using the traditional sinusoidal pulse width modulation (SPWM). The switching and conduction power losses are analyzed. Simulation and experimental results demonstrate the proposed method reduces CMV without comprising performance and efficiency of the APF integrated single-phase qZSI.

The life history of the Chinese mitten crab (Eriocheir japonica sinensis) includes two migrations: a feeding migration and a reproductive migration. Ambient salinity is one of the most critical factors during migration. In this study, the salinity adaptation mechanism of Chinese mitten crabs was simulated using continuous salinity changes. The expression of six key genes [Na+/K+-ATPase α subunit (NAK-α), V-type H+-ATPase subunit A (VHA-A), Zinc transporter (ZnT), Cl- channel protein 2 (CLCN2), ubiquitin/ribosomal S27 fusionprotein (S27), and glutathione S-transferase (GST)] and the activities of three enzymes [Na+/K+-ATPase (NAK), V-type H+-ATPase (VHA), and glutathione S-transferase (GST)] were evaluated in ten groups exposed to a range of salinity changes during mariculture based on the transcriptome data obtained from short term salinity-induced crabs (ES) compared to control group in freshwater crabs (EF). The results revealed that different genes exhibited different roles in physiological regulation. In total, 3,599 unigenes were significantly and differentially expressed in a comparison between the EF and ES treatments. A novel modulation of gene expression and the corresponding enzyme activity of NAK and VHA exhibited similar patterns. As genes related to osmoregulation, NAK and VHA showed similar patterns of both gene expression and enzyme activity in mariculture. During the gradual change in salinity from 0‰ to 25‰ and back to 0‰, the gene expression and enzyme activities of NAK and VHA initially increased (0‰ → 10‰), weakened (10‰ → 20‰) and then increased again (20‰ → 25‰ → 0‰). S27 could serve as a reference gene in the expression analysis of Chinese mitten crabs under salinity stress. ZnT and CLCN2 were involved in osmoregulation as functional proteins. Our findings provide insights into the regulation mechanisms employed during the migration of the Chinese mitten crab.

Background The swimming crab, Portunus trituberculatus, is an important commercial species in China and is widely distributed in the coastal waters of Asia-Pacific countries. Despite increasing interest in swimming crab research, a high-quality chromosome-level genome is still lacking. Findings Here, we assembled the first chromosome-level reference genome of P. trituberculatus by combining the short reads, Nanopore long reads, and Hi-C data. The genome assembly size was 1.00 Gb with a contig N50 length of 4.12 Mb. In addition, BUSCO assessment indicated that 94.7% of core eukaryotic genes were present in the genome assembly. Approximately 54.52% of the genome was identified as repetitive sequences, with a total of 16,796 annotated protein-coding genes. In addition, we anchored contigs into chromosomes and identified 50 chromosomes with an N50 length of 21.80 Mb by Hi-C technology. Conclusions We anticipate that this chromosome-level assembly of the P. trituberculatus genome will not only promote study of basic development and evolution but also provide important resources for swimming crab reproduction.

Crop production has negative effect on the biodiversity in farmlands because of less crop varieties and intensive soil disturbance. Macrofauna are important components of the belowground biodiversity, and contribute to the soil ecosystem functions and soil processes. The response of soil macrofauna to cropping pattern is crucial for understanding the soil ecological dynamics and biodiversity conservation. Herein, we established an experiment of rice (Oryza sativa L.)-based double cropping system in Jiangsu Province, China since 2016 to evaluate the effects of rotation regimes on soil properties and soil macrofauna communities. The rice-based double cropping system included rice–wheat (Triticum aestivum L.), rice-oilseed rape (Brassica campestris L.), rice-tiny vetch (Vicia hirsuta L.), rice-broad bean (Vicia faba L.), and rice-fallow. After 3-year rotations, soil macrofaunal biodiversity and trophic structure varied significantly with soil properties. The higher biodiversity indices were found in the tiny vetch (used as green manure in situ) and fallow fields. In addition, soil organic carbon (SOC), the main factor for shaping the soil environment and regulating the soil macrofaunal communities, was improved. While soil water content and pH were selected to predict each trophic richness and density in most of the optimal regression models, changes in soil macrofaunal communities should also be considered as comprehensive responses to the soil environments (food resources, microhabitats etc.) co-varying rotation regimes. Crop rotation with lower intensity of land use increased the complexity of soil macrofaunal trophic structure. Green manure fields or fallow after rice plantation promoted soil macrofaunal biodiversity in the rice-based cropping system.

A dc-link voltage balancing control strategy for quasi-Z-source cascaded H-bridge (qZS-CHB) inverter photovoltaic (PV) power system is proposed by using multidimensional pulse-width modulation (MD-PWM) technique. The qZS-CHB PV system usually employs proportional-integral (PI) regulators based closed-loop control methods to balance dc-link voltages, combining with distributed maximum power point tracking and grid-tie power control. These require significant control computations and hardware resources for multiple modules based qZS-CHB system. The proposed MD-PWM for the qZS-CHB inverter performs shoot-through behavior based on geometric representation of the output voltage ranges of each H-bridge in coordinate axes. All possible switching sequences of the qZS-CHB inverter are taken into account to choose the most suitable sequence that can balance dc-link voltages of qZS modules in the qZS-CHB PV power system. When compared with the state-of-the-art of voltage balancing control methods, the proposed control strategy has advantages: 1) The computation is low because there is no PI controller, while the stability of the whole system is improved; and 2) there is a reliable balancing capability with fast regulation of dc-link voltages, owing to no extra controller parameters and handling the voltage balance in each control cycle. Simulation and experimental results of qZS-CHB inverter based grid-tie PV power system verify the proposed dc-link voltage balancing control technique.

Quasi-Z source indirect matrix converter (QZS-IMC) has been proved to have abilities of voltage boost, current filtering, variable voltage, and variable frequency. The voltage gain of QZS-IMC depends on QZS network shoot-through duty ratio D , rectifier modulation ratio $m_{i}$ , and inverter modulation ratio $m_{o}$ . Their multiple combinations are able to achieve the same voltage gain, but determining which is the optimal has not been addressed. In addition, the size of D is associated with the duration of shoot-through events of the QZS network, voltage and current stresses of power devices, and the system power losse. This paper proposes to find the optimal operation curve of D based on the constrained optimization theory. Simulation and experimental results validate theoretical analysis, the proposed optimal control, and the power loss reduction of the QZS-IMC.

A quasi-Z-source three-to-single-phase matrix converter is proposed with low-frequency ripple power compensation. The employed impedance network between the source grid and the matrix converter extends the voltage gain; meanwhile, it has filtering function. Therefore, voltage step-up devices and an additional input filter are avoided. In addition, for a conventional three-to-single-phase matrix converter, input current of the source grid contains high harmonic components because of double-line-frequency pulsating power produced in single-phase side. A model predictive control-based ripple power compensation system is proposed in this paper to eliminate the low-order harmonic components from the three-phase input currents and voltages. Thus, the impedance parameters could be small in size and value. Simulation and experimental results verify the analysis and control of the proposed topology.

The battery energy-stored quasi-Z-source (BES-qZS)-based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. However, the second-harmonic ( ${\text{2}}\omega $ ) power ripple degrades the system's performance and affects the system's design. An accurate model to analyze the ${\text{2}}\omega $ ripple is very important. The existing models did not consider the battery, or assumed a symmetric qZS network with $L_{{1}}= L_{{2}}$ and $C_{{1}}= C_{{2}}$ , which limits the design freedom and causes oversized impedance parameters. This paper proposes a comprehensive model for the single-phase BES-qZS-PV inverter system, where the battery is considered and there is no restriction of $L_{{1}}= L_{{2}}$ and $C_{{1}}= C_{{2}}$ . Based on the built model, a BES-qZS impedance design method is proposed to mitigate the ${\text{2}}\omega $ ripple with asymmetric qZS network. Simulation and experimental results verify the proposed ${\text{2}}\omega $ ripple model and impedance design method.

A battery-energy-stored quasi-Z-source cascaded multilevel inverter (qZS-CMI)-based photovoltaic (PV) power generation system combines advantages of a qZS inverter, a CMI, and a battery energy storage system. However, unbalanced battery state of charge (SOC) between cascaded H-bridge inverter modules will degrade an entire system's performance and shorten battery lifespan. This paper proposes a control method to balance battery SOCs of all modules, no matter the intermittent states of each module's PV power. The method is on the basis of battery SOCs, SOC limits of each module, and the total power injected into the power grid. Simulation and experimental results verify the proposed control method that ensures identical SOCs for the battery-energy-stored qZS-CMI PV system.

The pulse-width amplitude modulation (PWAM) method was proposed for the single-phase quasi-Z-source inverter (qZSI)-based photovoltaic (PV) power system to reduce quasi-Z-source (qZS) impedance values while improving efficiency. The method modified sinusoidal pulse-width modulation (SPWM) of the qZSI by combining pulse-amplitude modulation (PAM) and a varied dc-link voltage envelope was produced. The SPWM worked at low dc-link voltage, lowering voltage stress and avoiding shoot-through switching. The PAM worked at the varied dc-link voltage, reducing the number of switching events. As a result, the power dissipation decreased compared to working at the constant dc-link voltage. This study further investigates the PWAM-based single-phase qZS PV inverter system. An improved topology with control strategy is proposed for its grid-connected and standalone operation. Design method of impedance parameters is detailed. The performance in boost and buck operation is discussed when the single-phase qZSI using SPWM and PWAM. Simulation and experimental results verify outstanding features of the PWAM for single-phase qZSI, and the proposed approach for dual-mode operation of the PWAM-based single-phase qZS PV power system.

Double-line frequency ripple power is inherent in single-phase rectifiers and inverters, and, if not managed properly, it can be adverse to system performance at both the ac and dc sides. Therefore, numerous active power-decoupling techniques have been introduced to decouple the double-line frequency ripple power. However, no comprehensive comparisons are available on the permitted minimum capacitance for power decoupling, dc voltage utilization, current stress, modulation complexity, and even application evaluations, except for power rating and component counts. All of these aspects are critical when choosing appropriate power-decoupling techniques for different applications. In this article, the minimum capacitance to decouple the ripple power and the current stress of power devices in the main circuit are derived in light of different voltages across energy storage capacitors. By considering the ripple power paths, we investigate the dc voltage utilization of both the main circuit and power-decoupling circuit. Combined with other features, including component counts and modulation complexity, the overall characteristics of different power-decoupling techniques are compared and summarized to effectively evaluate their performance in different applications.

WRKY proteins are a large family of plant transcription factors, which play an important role in many biological processes such as plant development, metabolism, and responses to biotic and abiotic stresses. This study aimed to develop a complete overview of the WRKY family by using the potato genome. Based on the genome-wide analysis, a total of 82 StWRKY proteins were characterized and classified into three groups (I, II, and III) and five subgroups (IIa, IIb, IIc, IId, and IIe) according to the sequence similarity, motif varieties, and their phylogenetic relationships. By using multiple sequence alignment, a novel motif, WRKYGQR, was identified from StWRKY076 along with three variations of the WRKYGQK heptapeptide (WRKYGMK, WHKCGQK, and WRKYGKK) that might execute new biological functions. Chromosomal location analysis showed that the 82 StWRKY proteins were located in 11 of the 12 chromosomes, excluding chromosome 11. Phylogenetic analyses also showed that the 82 StWRKY proteins could be clustered into three large groups and five subgroups which shared typical characters of WRKY. The results provide fundamental information to inform further analysis and understanding of WRKY gene functions in potato.