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Science

Abstract The yellow-throated marten (Martes flavigula) is a medium-sized carnivore that is widely distributed across much of Asia and occupies an extensive variety of habitats. We reported a high-quality genome assembly of this organism that was generated using Oxford Nanopore and Hi-C technologies. The final genome sequences contained 215 contigs with a total size of 2,449.15 Mb and a contig N50 length of 68.60 Mb. Using Hi-C analysis, 2,419.20 Mb (98.78%) of the assembled sequences were anchored onto 21 linkage groups. Merqury evaluation suggested that the genome was 94.95% complete with a QV value of 43.75. Additionally, the genome was found to comprise approximately 39.74% repeat sequences, of which long interspersed elements (LINE) that accounted for 26.13% of the entire genome, were the most abundant. Of the 20,464 protein-coding genes, prediction and functional annotation was successfully performed for 20,322 (99.31%) genes. The high-quality, chromosome-level genome of the marten reported in this study will serve as a reference for future studies on genetic diversity, evolution, and conservation biology.

Applied sciences, Energy management, Energy storage, and Science

Summary: Batteries may degrade fast at extreme temperatures, posing a challenge in meeting the dual requirements of heat preservation at low temperatures and efficient cooling at high temperatures. To address this issue, we propose a cavity structure-based active controllable thermal switch. It has a potential switch ratio (SR) of approximately 300, with an experimental SR of 15.4. Furthermore, the thermal resistance can be actively controlled. The “OFF State” of the thermal switch increases energy discharge at low temperatures. Pre-heating with the “OFF State” consumes only 60% of the energy required in the “ON State”. By employing the “ON State” at an ambient temperature of 20°C, the battery temperature can be maintained below 35°C. And the “ON + State” keeps the maximum battery temperature remaining below 42°C under extreme conditions. These findings demonstrate that the implementation of the proposed thermal switch enhances the usability of batteries in extreme environments.

Materials of engineering and construction. Mechanics of materials and TA401-492

Abstract To prevent volcanic ash corrosion using thermal barrier coatings (TBCs), a novel method using Al2O3-modification was proposed to reduce molten CMAS wettability on TBCs surface through a lotus effect. Plasma spray-physical vapor deposition (PS-PVD), a third-generation method for TBCs fabrication, was adopted to deposit 7YSZ TBCs with a feather-like microstructure. Then, Al2O3 modification was introduced to fabricate a dense Al2O3 overlay with nano/micro-sized grains on the TBCs surface. The wetting ability of CMAS on APS/EB-PVD/PS-PVD 7YSZ TBCs was comparatively in situ observed at 1250 °C for 3600 s. The results indicated that the dense Al2O3 overlay inhibited penetration of molten CMAS. Additionally, the micro/nano dual-sized structure, which is similar to the papillary structure of a lotus leaf, reduced molten CMAS wettability on the TBCs surface. The results demonstrated that the Al2O3-modified TBCs had better CMAS corrosion resistance than the as-deposited APS/EB-PVD/PS-PVD TBCs.

Learning from demonstration, Dynamic movement primitives, 2D sphere manifold, Gaussian mixture model, Gaussian mixture regression, Quaternion-based orientation, Ocean engineering, TC1501-1800, Mechanical engineering and machinery, and TJ1-1570

Abstract Dynamic movement primitives (DMPs) as a robust and efficient framework has been studied widely for robot learning from demonstration. Classical DMPs framework mainly focuses on the movement learning in Cartesian or joint space, and can't properly represent end-effector orientation. In this paper, we present an extended DMPs framework (EDMPs) both in Cartesian space and 2-Dimensional (2D) sphere manifold for Quaternion-based orientation learning and generalization. Gaussian mixture model and Gaussian mixture regression (GMM-GMR) are adopted as the initialization phase of EDMPs to handle multi-demonstrations and obtain their mean and covariance. Additionally, some evaluation indicators including reachability and similarity are defined to characterize the learning and generalization abilities of EDMPs. Finally, a real-world experiment was conducted with human demonstrations, the endpoint poses of human arm were recorded and successfully transferred from human to the robot. The experimental results show that the absolute errors of the Cartesian and Riemannian space skills are less than 3.5 mm and 1.0°, respectively. The Pearson’s correlation coefficients of the Cartesian and Riemannian space skills are mostly greater than 0.9. The developed EDMPs exhibits superior reachability and similarity for the multi-space skills’ learning and generalization. This research proposes a fused framework with EDMPs and GMM-GMR which has sufficient capability to handle the multi-space skills in multi-demonstrations.

Rock and soil, Heat transfer, Pre-drilling thermal probe testing equipment, In-situ test, Engineering (General). Civil engineering (General), and TA1-2040

At present, the in-situ testing equipment used for measuring the thermophysical properties of rock and soil is scarce. Based on the working principle of the pressuremeter and ground heat exchanger, a pre-drilling thermal probe in-situ testing equipment is developed. This novel developed pre-drilling thermal probe in-situ testing equipment includes thermal probe, pressure control system, temperature control system, integrated conversion control device, and coaxial pressure pipe connection pipeline. A three-dimensional heat transfer model was established to simulate the heat transfer between the thermal probe and surrounding ground. Based on the principle of the temperature dissipation and numerical simulation, a calculation method for the thermal conductivity of rock and soil with pre-drilling thermal probe is proposed. Laboratory model tests of the sand under dry and saturated conditions were conducted. The deviation values for the thermal conductivities of sand under dry and saturated conditions measured by the designed pre-drilling thermal probe and thermal conductivity tester are 0.037 and 0.026 W/m·°C, respectively. Thus, the reliability of utilizing the new pre-drilling thermal probe testing equipment to measure the thermal conductivity of the soil is confirmed. The field test of utilizing this new pre-drilling thermal probe testing equipment to measure the thermal properties of the soil was performed. The results show that because the soil layers are in undisturbed state during the test process, the pre-drilling thermal probe testing equipment can truly reflect the inherent thermal properties of different soil layers.

Femtosecond laser, Superhydrophobic microchannel, Micro-nano structure, Drag-reduction, Materials of engineering and construction. Mechanics of materials, and TA401-492

The superhydrophobic silica glass microchannel with flow drag reduction performance has broad application prospects. In response to this demand, this paper proposes an integrated design and preparation method of structure and function for drag reduction microchannels on the silica glass surface. The design method of geometric parameters of stable superhydrophobic silica glass surface structures with a periodic micropillar array is studied based on the drag reduction mechanism of superhydrophobic surfaces. Combined with the plasma deposition process, the drag-reducing superhydrophobic silica glass surface is successfully prepared by femtosecond laser technology. The prepared drag-reducing superhydrophobic silica glass surface shows good composite wetting state stability under different test conditions. The drag-reducing superhydrophobic functional structure with a micropillar array is prepared at the bottom of the silica glass microchannels by femtosecond laser direct writing technology. Moreover, the effective integration of the silica glass microchannel structure and the drag-reducing functional structure is achieved. The preparation and flow performance test of microfluidic devices demonstrates that drag-reduction microchannels of silica glass can significantly reduce microfluidic flow resistance. The proposed method effectively improves the functional characteristics of ultrafast laser processing surface microchannels in silica glass and has broad application prospects in fluid flow and control.

black-billed capercaillie (Tetrao parvirostris), fecal microbiome, function prediction, high-throughput sequencing, Veterinary medicine, SF600-1100, Zoology, and QL1-991

Black-billed capercaillie (Tetrao parvirostris) was listed as a first-class state-protected animal because it was endangered in China (Category I). This study is the first to examine the diversity and composition of T. parvirostris gut microbiome in the wild. We collected fecal samples from five black-billed capercaillie flock roosting sites (each 20 km apart) in one day. Thirty fecal samples were sequenced with 16S rRNA gene amplicons on the Illumina HiSeq platform. This study is the first to analyze the fecal microbiome composition and diversity of black-billed capercaillie in the wild. At the phylum level, Camplyobacterota, Bacillota, Cyanobacteria, Actinomycetota, and Bacteroidota were the most abundant in the fecal microbiome of black-billed capercaillie. At the genus level, unidentified Chloroplast, Escherichia−Shigella, Faecalitalea, Bifidobacterium, and Halomonas were the dominant genera. Based on alpha and beta diversity analyses, we found no significant differences in the fecal microbiome between five flocks of black-billed capercaillie. Protein families: genetic information processing; protein families: signaling and cellular processes, carbohydrate metabolism; protein families: metabolism and energy metabolism are the main predicted functions of the black-billed capercaillie gut microbiome through the PICRUSt2 method. This study reveals the composition and structure of the fecal microbiome of the black-billed capercaillie under wild survival conditions, and this study provides scientific data for the comprehensive conservation of the black-billed capercaillie.

convergent evolution, gut microbiome, marine carnivores, marine habitat, Ecology, and QH540-549.5

Abstract The gut microbiome can help the host adapt to a variety of environments and is affected by many factors. Marine carnivores have unique habitats in extreme environments. The question of whether marine habitats surpass phylogeny to drive the convergent evolution of the gut microbiome in marine carnivores remains unanswered. In the present study, we compared the gut microbiomes of 16 species from different habitats. Principal component analysis (PCA) and principal coordinate analysis (PCoA) separated three groups according to their gut microbiomes: marine carnivores, terrestrial carnivores, and terrestrial herbivores. The alpha diversity and niche breadth of the gut microbiome of marine carnivores were lower than those of the gut microbiome of terrestrial carnivores and terrestrial herbivores. The gut microbiome of marine carnivores harbored many marine microbiotas, including those belonging to the phyla Planctomycetes, Cyanobacteria, and Proteobacteria, and the genus Peptoclostridium. Collectively, these results revealed that marine habitats drive the convergent evolution of the gut microbiome of marine carnivores. This study provides a new perspective on the adaptive evolution of marine carnivores.

Space vector modulation (SVM), two-phase linear synchronous motor, winding segmented permanent magnet linear synchronous motor (WS-PMLSM), mover operation across sections, optimal control method, Electrical engineering. Electronics. Nuclear engineering, and TK1-9971

This paper presents a space vector modulation (SVM) technique for a two-phase winding segmented permanent magnet linear synchronous motor (WS-PMLSM). First, the advantages of the two-phase WS-PMLSM are discussed, the parameters related to the WS-PMLSM mathematical model are analyzed, and the SVM is applied to the implementation of the WS-PMLSM two-phase sinusoidal voltage inverter. Next, a feedforward implementation method is proposed considering the regularity characteristics of the mover cross-zone operation. Finally, in order to improve the smoothness of operation, an optimal calculation of the current values of each section according to the coverage is proposed, and an optimal control method is implemented by establishing an optimal efficiency model. The experimental results prove the effectiveness of the proposed method.

evolution, low atmospheric O2 levels, mtDNA protein‐coding genes, vertebrate, Ecology, and QH540-549.5

Abstract The high‐altitude environment may drive vertebrate evolution in a certain way, and vertebrates living in different altitude environments might have different energy requirements. We hypothesized that the high‐altitude environment might impose different influences on vertebrate mitochondrial genomes (mtDNA). We used selection pressure analyses and PIC (phylogenetic independent contrasts) analysis to detect the evolutionary rate of vertebrate mtDNA protein‐coding genes (PCGs) from different altitudes. The results showed that the ratio of nonsynonymous/synonymous substitutions (dN/dS) in the mtDNA PCGs was significantly higher in high‐altitude vertebrates than in low‐altitude vertebrates. The seven rapidly evolving genes were shared by the high‐altitude vertebrates, and only one positive selection gene (ND5 gene) was detected in the high‐altitude vertebrates. Our results suggest the mtDNA evolutionary rate in high‐altitude vertebrates was higher than in low‐altitude vertebrates as their evolution requires more energy in a high‐altitude environment. Our study demonstrates the high‐altitude environment (low atmospheric O2 levels) drives vertebrate evolution in mtDNA PCGs.

gut microbiome, ungulates, phylogeny, high-altitude, convergent evolution, Microbiology, and QR1-502

Convergent evolution is an important sector of evolutionary biology. High-altitude environments are one of the extreme environments for animals, especially in the Qinghai Tibet Plateau, driving the inquiry of whether, under broader phylogeny, high-altitude factors drive the convergent evolution of Artiodactyla and Perissodactyla gut microbiomes. Therefore, we profiled the gut microbiome of Artiodactyla and Perissodactyla at high and low altitudes using 16S rRNA gene sequencing. According to cluster analyses, the gut microbiome compositions of high-altitude Artiodactyla and Perissodactyla were not grouped together and were far from those of low-altitude Artiodactyla and Perissodactyla. The Wilcoxon’s test in high-altitude ungulates showed significantly higher Sobs and Shannon indices than in low-altitude ungulates. At the phylum level, Firmicutes and Patescibacteria were significantly enriched in the gut microbiomes of high-altitude ungulates, which also displayed a higher Firmicutes/Bacteroidetes value than low-altitude ungulates. At the family level, Ruminococcaceae, Christensenellaceae, and Saccharimonadaceae were significantly enriched in the gut microbiomes of high-altitude ungulates. Our results also indicated that the OH and FH groups shared two significantly enriched genera, Christensenellaceae_R_7_group and Candidatus_Saccharimonas. These findings indicated that a high altitude cannot surpass the order level to drive the convergent evolution of ungulate gut microbiome composition but can drive the convergent evolution of alpha diversity and indicator microbiota in the gut microbiome of ungulates. Overall, this study provides a novel perspective for understanding the adaptation of ungulates to high-altitude environments.

Ag nanowires, nanocontacts, morphological characteristics, atomic configuration, MD simulation, Materials of engineering and construction. Mechanics of materials, TA401-492, Industrial engineering. Management engineering, T55.4-60.8, Physics, and QC1-999

Ag nanowires (AgNWs) have shown great application value in the field of flexible electronics due to their excellent optical and electrical properties, and the quality of its joints of AgNWs in the thin film network directly plays a key role in its performance. In order to further improve the joint quality of AgNWs under thermal excitation, the thermal welding process and atomic evolution behavior of AgNWs were investigated through a combination of in situ experimental and molecular dynamics simulations. The influence of processing time, temperature, and stress distribution due to spatial arrangement on nanojoints was systematically explored. What is more, the failure mechanisms and their atomic interface behavior of the nanojoints were also investigated.

Urology robot, Dynamic simulation, Virtual prototyping, Serial manipulator, Feedforward control, Ocean engineering, TC1501-1800, Mechanical engineering and machinery, and TJ1-1570

Abstract Prostatic hyperplasia and tumor are common diseases, and the minimally invasive surgery inserting the instruments through the urethra into the prostate is commonly conducted. Taking the robotic manipulator for such surgery into consideration, this paper analyses the workspace of the end effector, and proposes the distribution error of the fixed point and the tracking error of manipulator end effector on the cone bottom surface of the workspace as the basis for control implementation of the manipulator. The D-H coordinate system of the manipulator is established and the trajectory planning of the end effector in the Cartesian space is carried out. The digital model was established, and dynamics simulation was performed in Solidworks and Matlab/Simulink environment to guide the manipulator design. Trajectory mapping and synchronization control between virtual model and the actual manipulator are realized based on digital twin technique. The virtual manipulator can reflect the real-time state of the manipulator with data interaction by comparing the dynamics simulation results with the motor current values obtained by experiment. Experiment was carried out with PD feedback control and Newton–Euler dynamics based feedforward control to get the trajectory tracking characteristic of each motor, errors of the fixed point and tracking performance of the end effector of the manipulator. The results show that compared with PD feedback control, feed forward control implementation can achieve a reduction of 30.0% in the average error of the fixed point of the manipulator and a reduction of 33.3% in the maximum error.

Absolute magnetic encoder, Vernier decoding, ellipse parameter identification, recursive-least-squares dual second-order generalized integrator (RLS-DSOGI), winding segmented permanent magnet linear synchronous motor (WS-PMLSM), Electrical engineering. Electronics. Nuclear engineering, and TK1-9971

The winding segmented permanent magnet linear synchronous motor has restrictions on the last absolute position acquisition when the power goes from off to on, and the traditional absolute position acquisition systems depend on complex battery and calibration systems. Therefore, a true absolute magnetic encoder based on the Vernier principle with error rejection and decoding technology is studied in this paper. First, the output signal of the magnetic encoder with noise was subjected to the adaptive ellipse parameter correction algorithm with recursive least squares (RLS), and the source output signal predicted and reconstructed. Furthermore, the RLS was optimized by the speed weighting factor and the forgetting factor to reduce the computational pressure and the iterative process. Second, one improved double second-order generalized integrator(DSOGI) decoding technology was investigated by extracting and separating the symmetric-positive sequence components in the unbalanced signal, and, using the phase-locked loop technique for tracking calculation, accurate speed and angle obtained. The adaptive ellipse parameter fitting algorithm effectively reduced the problem of overshoot and steady-state error of the DSOGI, which provides a practical and theoretical basis for the future application of the magnetic encoder. This trajectory arrangement not only avoids the influence of accumulated error on the accuracy of encoder, but it also solves the contradiction between high resolution and small volume, and the advantages over the special decoding chip IC-Haus were also verified by comprehensive experimental results.

Chemistry and QD1-999

Gobiidae, evolution, mitogenome, positive selection, adaptation, Veterinary medicine, SF600-1100, Zoology, and QL1-991

The Gobiidae family occupy one of the most diverse habitat ranges of all fishes. One key reason for their successful colonization of different habitats is their ability to adapt to different energy demands. This energy requirement is related to the ability of mitochondria in cells to generate energy via oxidative phosphorylation (OXPHOS). Here, we assembled three complete mitochondrial genomes of Rhinogobius shennongensis, Rhinogobius wuyanlingensis, and Chaenogobius annularis. These mitogenomes are circular and include 13 protein-coding genes (PCGs), two rRNAs, 22 tRNAs, and one non-coding control region (CR). We used comparative mitochondrial DNA (mtDNA) genome and selection pressure analyses to explore the structure and evolutionary rates of Gobiidae mitogenomics in different environments. The CmC model showed that the ω ratios of all mtDNA PCGs were adenosine triphosphate 8 (atp8) was faster in Gobiidae than in other mitochondrial DNA PCGs. We also found evidence of positive selection for several sites of NADH dehydrogenase (nd) 6 and atp8 genes. Thus, divergent mechanisms appear to underlie the evolution of mtDNA PCGs, which might explain the ability of Gobiidae to adapt to diverse environments. Our study provides new insights on the adaptive evolution of Gobiidae mtDNA genome and molecular mechanisms of OXPHOS.

PMSM, FPGA, torque predictive control, motor drive, Mechanical engineering and machinery, and TJ1-1570

With the increasing demand for legged robots, the importance of the joint drive is increasing. The dynamic performance of the inner-most torque/current control loop conditions the capabilities of the whole joint system. In this paper, a direct torque control based on a prediction model is proposed. The motor torque is estimated by considering calculation and measurement delay; error estimation and torque tracking error are observed and compensated. The control algorithm was implemented on a Field Programmable Gate Array (FPGA) board to apply the capabilities of concurrency calculation of the FPGA. The effectiveness of the proposed control algorithm was experimentally verified. Compared with the commonly used Field Oriented Control (FOC) current controller, the presented controller can not only improve the dynamic performance of the motor but also reduce the average switching times of the inverter.

inductance, winding segmented permanent magnet linear synchronous motor, magnetomotive force, specific permeability function, Mathematics, and QA1-939

The inductance of a winding segmented permanent magnet linear synchronous motor (WS-PMLSM) is affected by winding disconnection and coupling length variation, which makes the variation of inductance more complicated, and this paper proposes incremental inductance, apparent inductance, and positional inductance to reveal this phenomenon, which gives a theoretical basis for mathematical modeling and thrust fluctuation suppression. First, an analytical approach is used to derive a fully coupled state model using the magnetomotive force and specific permeability function. Second, the domain of the specific permeability function is extended and the inductance expressions are calculated for the whole moving range. Finally, the inductance of the prototype WS-PMLSM with a two-phase winding is experimentally verified, and it is proposed that the effects of the three inductive components on the system should be considered comprehensively when implementing control of the WS-PMLSM.