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Traditional scenic route planning only considers the shortest path, which ignores the information of scenic road conditions. As the most effective direct search method to solve the shortest path in static road network, A* algorithm can plan the optimal scenic route by comprehensively evaluating the weights of each expanded node in the gridded scenic area. However, A* algorithm has the problem of traversing more nodes and ignoring the cost of road in the route planning. In order to bring better travel experience to the travelers, the above factors are taken into account. This paper presents a path planning method based on the improved A* algorithm. Firstly, the heuristic function of the A* algorithm is weighted by exponential decay to improve the calculation efficiency of the algorithm. Secondly, in order to increase the practicality of the A* algorithm, the impact factors that road conditions is introduced to the evaluation function. Finally, the feasibility of the improved A* algorithm is verified through simulation experiments. Experimental results show that the improved A* algorithm can effectively reduce the calculation time and road cost.

The development of cost-effective hydroxide exchange membrane fuel cells is limited by the lack of high-performance and low-cost anode hydrogen oxidation reaction catalysts. Here we report a Pt-free catalyst Ru 7 Ni 3 /C, which exhibits excellent hydrogen oxidation reaction activity in both rotating disk electrode and membrane electrode assembly measurements. The hydrogen oxidation reaction mass activity and specific activity of Ru 7 Ni 3 /C, as measured in rotating disk experiments, is about 21 and 25 times that of Pt/C, and 3 and 5 times that of PtRu/C, respectively. The hydroxide exchange membrane fuel cell with Ru 7 Ni 3 /C anode can deliver a high peak power density of 2.03 W cm −2 in H 2 /O 2 and 1.23 W cm −2 in H 2 /air (CO 2 -free) at 95 °C, surpassing that using PtRu/C anode catalyst, and good durability with less than 5% voltage loss over 100 h of operation. The weakened hydrogen binding of Ru by alloying with Ni and enhanced water adsorption by the presence of surface Ni oxides lead to the high hydrogen oxidation reaction activity of Ru 7 Ni 3 /C. By using the Ru 7 Ni 3 /C catalyst, the anode cost can be reduced by 85% of the current state-of-the-art PtRu/C, making it highly promising in economical hydroxide exchange membrane fuel cells. Development of hydroxide exchange membrane fuel cells (HEMFCs) requires high-performance and low-cost catalysts for hydrogen oxidation reaction at the anode. Here the authors report Ru 7 Ni 3 /C as anode catalysts, delivering high power density and good durability in alkaline media for HEMFCs.

Boron (B)- and sulfur (S)-doped polycyclic aromatic hydrocarbons (PAHs) are developed as a novel kind of multiple resonance emitters for ultrapure blue thermally activated delayed fluorescence (TADF) polymers with narrowband electroluminescence. The combination of electron-deficient B atom and electron-rich S atom in PAH can form an intramolecular push-pull electronic system in a rigid aromatic framework, leading to reduced singlet-triplet energy splitting and limited structure relaxation of excited states. The critical roles of S atom in determining emission properties with respect to the oxygen analogues are in two aspects: (i) reducing energy bandgap to shift emission from human-eye-insensitive ultraviolet zone to blue region, and (ii) promoting reverse intersystem crossing process by heavy-atom effect to activate TADF effect. The resulting polymer containing B,S-doped PAH as emitter and acridan as host exhibits efficient blue electroluminescence at 458 nm with small full-width at half-maximum of 31 nm, representing the first example for ultrapure TADF polymer with narrowband electroluminescence.

High-performance platinum-group-metal-free alkaline hydrogen oxidation reaction catalysts are essential for the hydroxide exchange membrane fuel cells, which generally require high Pt loadings on the anode. Herein, we report a highly active hydrogen oxidation reaction catalyst, NiCuCr, indicated by the hydroxide exchange membrane fuel cell with a high peak power density of 577 mW cm −2 (18 times as high as the Ni/C anode) and a stability of more than 150 h (a degradation rate slower by 7 times than the Ni/C anode). The spectroscopies demonstrate that the alloy effect from Cu weakens the hydrogen binding, and the surface Cr 2 O 3 species enhance the interfacial water binding. Both effects bring an optimized apparent hydrogen binding energy and thus lead to the high hydrogen oxidation reaction performance of NiCuCr. These results suggest that the apparent hydrogen binding energy determines the hydrogen oxidation reaction performance and that its tuning is beneficial toward high electrocatalytic performance. Nickel-based electrocatalysts for the hydrogen oxidation reaction in hydroxide exchange membrane fuel cells show promise, but their activity requires further enhancement. Here, the authors report NiCuCr alloy with high activity, owing to the efficient tuning of both hydrogen and water binding on Ni sites by alloying with Cu and Cr.

Hydroxide exchange membrane fuel cells (HEMFCs) have the advantages of using cost-effective materials, but hindered by the sluggish anodic hydrogen oxidation reaction (HOR) kinetics. Here, we report an atomically dispersed Ir on Mo 2 C nanoparticles supported on carbon (Ir SA -Mo 2 C/C) as highly active and stable HOR catalysts. The specific exchange current density of Ir SA -Mo 2 C/C is 4.1 mA cm −2 ECSA , which is 10 times that of Ir/C. Negligible decay is observed after 30,000-cycle accelerated stability test. Theoretical calculations suggest the high HOR activity is attributed to the unique Mo 2 C substrate, which makes the Ir sites with optimized H binding and also provides enhanced OH binding sites. By using a low loading (0.05 mg Ir cm −2 ) of Ir SA -Mo 2 C/C as anode, the fabricated HEMFC can deliver a high peak power density of 1.64 W cm −2 . This work illustrates that atomically dispersed precious metal on carbides may be a promising strategy for high performance HEMFCs. High-performance hydroxide exchange membrane fuel cells rely on the anode loading of platinum-group metals. Here, the authors report a highly active hydrogen oxidation electrocatalyst which contains atomically dispersed Ir on Mo2C nanoparticles supported on a carbon substrate.

Efficient and effective radar emitter recognition is critical for electronic support measurement (ESM) systems. However, in complex electromagnetic environments, intercepted pulse trains generally contain substantial data noise, including spurious and missing pulses. Currently, radar emitter recognition methods utilizing traditional artificial neural networks (ANNs) like CNNs and RNNs are susceptible to data noise and require intensive computations, posing challenges to meeting the performance demands of modern ESM systems. Spiking neural networks (SNNs) exhibit stronger representational capabilities compared to traditional ANNs due to the temporal dynamics of spiking neurons and richer information encoded in precise spike timing. Furthermore, SNNs achieve higher computational efficiency by performing event-driven sparse addition calculations. In this paper, a lightweight spiking neural network is proposed by combining direct coding, leaky integrate-and-fire (LIF) neurons, and surrogate gradients to recognize radar emitters. Additionally, an improved SNN for radar emitter recognition is proposed, leveraging the local timing structure of pulses to enhance adaptability to data noise. Simulation results demonstrate the superior performance of the proposed method over existing methods.

Three kinds of through-space charge transfer (TSCT) blue polymers containing non-conjugated polystyrene backbone together with spatially-separated acridan donor and oxygen-bridged triphenylboron acceptors having different substituents of tert -butyl, hydrogen and fluorine are designed and synthesized. The designed TSCT blue polymers possess photoluminescence quantum yields up to 70% in solid-state film, single-triplet energy splitting below 0.1 eV, and typical thermally activated delayed fluorescence (TADF) effect. Meanwhile, the resulting polymers exhibit aggregation-induced emission (AIE) effect with emission intensity increased by up to ~27 folds from solution to aggregation state. By changing the substituent of acceptors to tune the charge transfer strength, blue emission with peaks from 444 to 480 nm can be realized for the resulting polymers. Solution-processed organic light-emitting diodes based on the polymers exhibit excellent device performance with Commission Internationale de L’Eclairage (CIE) coordinates of (0.16, 0.27), together with the maximum luminous efficiency of 30.7 cd A -1 and maximum external quantum efficiency of 15.0%, which is the best device efficiency for blue TADF polymers.

The changes in the Antarctic sea ice area are directly related to the changes in the atmosphere and oceans. Determining the Antarctic sea ice distribution is of great significance to the global climate change analysis. The ant colony algorithm adopts a positive feedback mechanism to continuously converge the search process and ultimately approaches the optimal solution, making it easy to find the optimal segmentation threshold for detecting the sea ice distribution. However, the ant colony algorithm has the problems of high computational complexity and easy getting stuck in local optima. In order to better apply the ant colony algorithm to sea ice distribution detection, an improved ant colony algorithm was proposed, which improves the selection of initial clustering centers and the update of pheromone volatilization factors in the ant colony algorithm. We compared the improved ant colony algorithm with iterative algorithm, maximum entropy algorithm, and basic global threshold algorithm, and the results showed that the proposed algorithm is feasible. To further validate the accuracy of the improved ant colony algorithm, we compared the results obtained from MODIS data with the improved ant colony algorithm, iterative algorithm, maximum entropy algorithm, and basic global threshold algorithm for sea ice detection, and the results showed that the accuracy of the proposed algorithm was 4.99%, 3.66%, and 5.46% higher than the other three algorithms, respectively.

Background and aim Mitochondrial genome has aseries of characteristics such as simple structure, no recombination, maternalinheritance, stable structure, fast evolution rate, and high copy number. Moreover, it is easy to be sequenced,contains high-resolution phylogenetic information, and exists in a wide rangeof taxa. Therefore, it is widely used in the study of biological phylogeny. Atpresent, phylogenetic studies focus mainly on D-loop region, cytochrome b gene,and protein-coding sequence. Phylogenetic studies using the mitochondrialcomplete sequence are rarely reported in yak. Therefore, the present studyaimed to construct phylogenetic tree using yak mitochondrial complete sequenceand compare the subsequent results with previous findings obtained usingpartial sequences. Results Complete mitochondrial sequences of five yakpopulations from Qinghai and Xinjiang were obtained. The mitotype diversity ofthe five populations was Xueduo yak (0.992 ± 0.015), Pamir yak (0.990 ± 0.014),Yushu yak (0.963 ± 0.033), Qilian yak (0.948 ± 0.036), and Huanhu yak (0.905 ±0.048), which showed a higher mitotype diversity compared with other breeds fromthe previous reports, including Jiulong yak, Maiwa yak, Zhongdian yak, andTianzhu yak. A total of 78 mitotypes were obtained from 111 individuals. Amongthese, Yushu yak, Huanhu yak, Xueduo yak, and Qilian yak all shared mitotypes,but the Pamir yak did not share mitotypes with these four populations.Phylogenetic analysis showed that yak populations were separable into threedistinct branches. The analysis identified a new phylogenetic branch containingboth wild and domestic yaks. The 155 mitotypes found in 206 individuals weredivided into 3 haplogroups by mitotype clustering. Thehaplogroup was not associated with the geographical distribution of yaks. Theyaks in the same population or the same ecological environment were distributedin different haplogroups. Among the threehaplogroups, haplogroup A and haplogroup B showed a star-shaped distribution ofmitotypes. The central mitotypes were widely distributed and had a highfrequency. Conclusions Thegenetic diversity of yaks in Qinghai was high. Both domestic and wild yaks clusteredinto three branches.

Background The Testis is an important reproductive organ in male mammals and the site for spermatogenesis, androgen synthesis, and secretion. Non-coding RNAs (ncRNAs) play an important regulatory role in various biological processes. However, the regulatory role of ncRNAs in the development of yak testes and spermatogenesis remains largely unclear. Result In this study, we compared the expression profiles of circular RNAs (circRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs) in yak testicular tissue samples collected at 6 months (Y6M), 18 months (Y18M), and 4 years (Y4Y). Using RNA sequencing (RNA-Seq), we observed a significant difference in the expression patterns of ncRNAs in the samples collected at different testicular development stages. Twenty-two differentially expressed (DE) circRNAs, 69 DE miRNAs, and 64 DE mRNAs were detected in Y6M, Y18M, and Y4Y testicular samples, respectively. The results of gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the source genes of DE circRNAs, predicted target genes of DE miRNAs, and DE mRNAs were specifically associated with signaling pathways and GO terms that were related to sperm synthesis, sperm vitality, and testicular development, such as cell cycle, Wnt signaling pathway, MAPK signaling pathway, GnRH signaling pathway, and spermatogenesis. The analysis of the circRNA-miRNA-mRNA network revealed that some DE ncRNAs, including miR-574, miR-449a, CDC42 , and CYP11A1 , among others, may be involved in testicular spermatogenesis. Concurrently, various circRNA-miRNA interaction pairs were observed. Conclusion Our findings provide a database of circRNAs, miRNAs, and mRNAs expression profiles in testicular tissue of yaks at different developmental stages and a detailed understanding of the regulatory network of ncRNAs in yak testicular development and provide data that can help elucidate the molecular mechanisms underlying yak testicular development.