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Satellite communication is widely used in fields such as encrypted communication and emergency communication. Its baseband processing algorithm is relatively complex and requires strong computing power support. Traditional FPGA and DSP platforms have a long development cycle, while GPU-based software-defined radio (SDR) solutions are convenient and have excellent performance. This paper proposes a group of baseband algorithms for satellite communication based on GPU, which realizes high-speed processing of the satellite communication downlink. Experimental results show that the GPU-based satellite communication link meets the lowest latency requirements, and the maximum baseband processing speed reaches 978Mbps. [ABSTRACT FROM AUTHOR]

Turbo Product Code (TPC) is a class of Forward Error Correction (FEC) codes that have good Bit Error Rate (BER) performance at high code rate. TPC is widely used in a variety of scenarios, such as satellite communication systems and data storage systems. This paper proposes a GPU-based parallel TPC decoder. In it, all rows or columns of the two-dimensional product code matrix can be translated at the same time. A parallel basic decoder is designed to simplify the decoding process of TPC consisting of extended Hamming code. The parallelization of test sample and effective code word calculation is realized? and the decoding delay is reduced. In order to further improve the decoding throughput? we propose a multi-channel TPC decoder. In addition, the performance of parallel decoders is measured on different GPUs. The experimental results show that the decoding delay of the GPU-based parallel decoder is significantly reduced compared with the CPU-based TPC decoder. In addition, the throughput of the GPU decoder reaches 30 Mbps on the Nvidia RTX 2080 Ti and 38 Mbps on the NVIDIA GTX Titan V, which is 44 times and 54 times the performance of the CPU-based decoder. [ABSTRACT FROM AUTHOR]

[Objective] To explore the biosynthetic pathway of ergothioneine in Naematelia aurantialba and Stereum hirsutum. [Method] The ergothioneine synthase gene Egt1 and Egt2 of N. aurantialba and S. hirsutum were cloned by PCR amplification technology, respectively, and their functions were analyzed by bioinformatics software. High performance liquid chromatography（HPLC）was used to identify the intermediate products of hercynine, ergothioneine and their contents in two species. [Result] The complete DNA sequences of Egt1 and Egt2 genes of two species were successfully cloned. The analysis using bioinformatics software revealed that Egt1 of the two species contained functional binding domains such as EgtD and SAM-dependent methyltransferase. Egt2 contained the binding sites for pyridoxal phosphate （LPL）and cysteine desulfurase. Further analysis indicated that Egt1 and Egt2 shared similar functional domains and substrate binding sites with model fungi（Schizosaccharomyces pombe and Neurospora crassa）. This result showed that Egt1 and Egt2 may have similar gene functions as these model fungi. HPLC analysis revealed the presence of hercynine and ergothioneine in N. aurantialba blastospore（JEYB）, S. hirsutum fermentum broth（ShFJY）, S. hirsutum mycelium（ShJST）and N. aurantialba fruiting bodies（JEZST）. Additionally, the ergothioneine content in the JEZST was found to be the highest at 113.19 μg/g, which was 7.45 times, 26.14 times, and 27.74 times higher than that of the JEYB, ShFJY, and ShJST, respectively. [Conclusion] The Egt1 and Egt2 genes of N. aurantialba and S. hirsutum were identified for the first time. It is hypothesized that the biosynthetic pathway of N. aurantialba and S. hirsutum are involved the catalysis of histidine by the Egt1 enzyme, resulting in the formation of hercynine. Subsequently, the Egt1 enzyme catalyzes the conversion of hercynine into hercynylcysteine sulfoxide. Finally, the Egt2 enzyme catalyzes the transformation of hercynylcysteine sulfoxide into ergothioneine. [ABSTRACT FROM AUTHOR]

Regarding to petroleum acids distribution in different fraction oils, solubility parameters of petroleum acids and solvents (alcohols, aromatics) in acid content determining standard were estimated by using the group contribution method, and mixed solvents and solutes with similar solubility parameters are the basis for improving the validity of determination. Solubility parameters theory was applied to analyze the relationship between solutes and solvents and the effect on the determination results, GB/T 258-2016, GB/T 4945-2002, GB/T 7304-2000, GB/T 18609-2011 were respectively demonstrated to determine the acid content of gasoline, diesel oil, lubricating oil and crude oil on the basis of meeting the national standards. The solvents and solutes were mutually soluble, and the end point was determined rapidly and accurately, so that determination of acid content was more scientific and effective. [ABSTRACT FROM AUTHOR]

Water clusters in metal complexes provide an effective way for the study on water in a macroscopic sense and water molecules related to protein molecules. In this paper, a supramolecular complex: [Co(2,2-bipy)2(N3)2](N3)0.5 Cl0.5·2H2 O (1, 2,2-bipy =2,2-bipyridine) containing an anion-water cluster was synthesized using 2,2-bipyridine and azide ion as ligands. Single crystal X-ray diffraction analysis reveals that complex 1 crystallizes in triclinic, P-1 space group with a =0.822 54(7) nm, b =1.175 58(9) nm, c =1.237 06(10) nm, α =91.379 0(10)°, β =92.151 0(10)°, γ =108.119 0(10)°, V =1.135 27(16) nm³, and it is composed of a mononuclear [Co(2,2-bipy)2(N3)2] + cation, two non-coordinating water molecules, 0. 5 free azide and chloride anions. The disordered azide and chloride anions have a site occupancy of 0. 5, respectively. The [Co(2,2-bipy)2(N3)2] + cations are connected to form a ribbon one-dimensional supramolecular structure through intermolecular C--H...π and π...π interactions. Two free water molecules and their crystallographically equivalent H2O molecules are connected each other to form a cyclic water tetramer by strong intermolecular hydrogen bonds, and then, a [(H2O)4 (N3)Cl]2 - anion-water cluster is obtained by the strong intermolecular hydrogen bonds between free water molecules and disordered N- 3 or Cl- ions. The quantum calculation of complex [Co(2,2-bipy)2(N3)2] + has been performed by density functional theory method. The single point energy and atomic charge were analyzed, and the oxidation state of the central metal ion was calculated. The results of the calculation are consistent with the experiments. [ABSTRACT FROM AUTHOR]