Effects of Quenching Methods and Aging Processes on the Crushing Properties and Microstructure of Al–Zn–Mg Alloy Thin-Walled Square Extrusions

Hui Guo,Jin Zhang,Cheng Wang,Yun‑lai Deng 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

In this study, the effects of different (online quenching and offline quenching) quenching methods and aging processes (T6and T73) on the crashworthiness and microstructural evolution of three Al–Zn–Mg alloys (G1–G3) were studied by conductingtensile test and axial compression tests at room temperature, combined with optical metallography, electron back scattereddiffraction, and transmission electron microscopy microstructural observations. The obtained results revealed that thecrushing properties of three different Al–Zn–Mg alloys subjected to different quenching methods and aging processes weresignificantly different. Their crushing energy absorption of are ranked as follows: G1 > G3 > G2. The highest total energyabsorption gap (between T6 and T73) is the G1 alloy, and the lowest one is the G3 alloy. The largest total energy absorptiongap between the two quenching methods is the G3 alloy, and the smallest one is the G1 alloy. The G2 alloy with the largesttotal amount of Zn + Mg has the highest number density of matrix precipitates, the largest precipitate gap (between T6 andT73) and the smallest precipitate gap between the two quenching methods. The G3 alloy with the largest Zn/Mg ratio hasthe smallest number density of matrix precipitates, the minimum precipitation gap (between T6 and T73) and the maximumprecipitation gap between the two quenching methods. The G1 alloy with the lowest Zn/Mg ratio has the smallest size ofgrain boundary precipitates and PFZ width, while their largest values are obtained for the G3 alloy with the maximum Zn/Mg ratio. As a crushing resistant structural material, the crushing properties is improved without reducing the strength. Theratio of Zn/Mg should be controlled within the range of 4.57–6.15, while the total amount of Zn + Mg should be controlledwithin the range of 6.18–7.01.

漢字 性質에 대한 討論 및 中國 漢字 初等敎育의 몇 가지 문제에 관하여

岑運强,郭莉,양원석(역) 한국한문교육학회 2003 한문교육논집 Vol.21 No.-

'語言의 언어 학(language-linguistics)'과 '言語의 언어학(speech-linguistics)'의 구분을 바탕으로 하여 다음에 대해 논의한다 : 1) 漢字의 性質 - 形 ·音 ·義관계, 文字의 類型, 변화와 形體 구조 ; 2) 중국 초등교육 漢字敎學의 몇 가지 대표적인 방법의 특징과 장단점 ; 3) 漢字敎學에 있어서의 과학과 비과학의 논쟁. On the basis of the distinction between language-linguistics and speech-linguistics, topics discussed in this paper are : 1) the nature of Chinese characters, including the relations among the appearance, the sound and the meaning of them, the character type they belong to, and the developmental and the body structures of them ; 2) the traits, advantages and disadvantages of several typical teaching methods of Chinese characters in elementary schools in mainland China ; 3) the struggles between science and pseudo-science in the teaching of Chinese characters.

Research progress in preparation of electrolyte for all-vanadium redox flow battery

Yun Guo,Jie Huang,Jun-Kai Feng 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

All-vanadium redox flow battery (VRFB), as a large energy storage battery, has aroused great concern ofscholars at home and abroad. The electrolyte, as the active material of VRFB, has been the research focus. The preparation technology of electrolyte is an extremely important part of VRFB, and it is the key tocommercial application of VRFB. In this work, the preparation methods of VRFB electrolyte are reviewed,with emphasis on chemical reduction, electrolysis, solvent extraction and ion exchange resin. The principles,technological processes, advantages and disadvantages of each method are briefly described. Theeffects of different additives on high concentration electrolyte are also introduced. Finally, the developmentof vanadium electrolyte preparation technology is prospected.

Fumigaclavine C attenuates adipogenesis in 3T3-L1 adipocytes and ameliorates lipid accumulation in high-fat diet-induced obese mice

Wan-Guo Yu,Yun He,Yun-Fang Chen,Xiao-Yao Gao,Wan-E Ning,Chun-You Liu,Ting-Fan Tang,Quan Liu,Xiao-Cheng Huang 대한약리학회 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.3

Fumigaclavine C (FC), an active indole alkaloid, is obtained from endophytic Aspergillus terreus (strain No. FC118) by the root of Rhizophora stylosa (Rhizophoraceae). This study is designed to evaluate whether FC has anti-adipogenic effects in 3T3-L1 adipocytes and whether it ameliorates lipid accumulation in highfat diet (HFD)-induced obese mice. FC notably increased the levels of glycerol in the culture supernatants and markedly reduced lipid accumulation in 3T3-L1 adipocytes. FC differentially inhibited the expressions of adipogenesis-related genes, including the peroxisome proliferator-activated receptor proteins, CCAAT/enhancer-binding proteins, and sterol regulatory element-binding proteins. FC markedly reduced the expressions of lipid synthesis-related genes, such as the fatty acid binding protein, lipoprotein lipase, and fatty acid synthase. Furthermore, FC significantly increased the expressions of lipolysis-related genes, such as the hormone-sensitive lipase, Aquaporin- 7, and adipose triglyceride lipase. In HFD-induced obese mice, intraperitoneal injections of FC decreased both the body weight and visceral adipose tissue weight. FC administration significantly reduced lipid accumulation. Moreover, FC could dosedependently and differentially regulate the expressions of lipid metabolism-related transcription factors. All these data indicated that FC exhibited anti-obesity effects through modulating adipogenesis and lipolysis.

Molecular Characterization of a Thermophilic and Salt- and Alkaline-Tolerant Xylanase from Planococcus sp. SL4, a Strain Isolated from the Sediment of a Soda Lake

( Xiao Yun Huang ),( Juan Lin ),( Xiu Yun Ye ),( Guo Zeng Wang ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.5

To enrich the genetic resource of microbial xylanases with high activity and stability under alkaline conditions, a xylanase gene (xynSL4) was cloned from Planococcus sp. SL4, an alkaline xylanase-producing strain isolated from the sediment of soda lake Dabusu. Deduced XynSL4 consists of a putative signal peptide of 29 residues and a catalytic domain (30-380 residues) of glycosyl hydrolase family 10, and shares the highest identity of 77% with a hypothetical protein from Planomicrobium glaciei CHR43. Phylogenetic analysis indicated that deduced XynSL4 is closely related with thermophilic and alkaline xylanases from Geobacillus and Bacillus species. The gene xynSL4 was expressed heterologously in Escherichia coli and the recombinant enzyme showed some superior properties. Purified recombinant XynSL4 (rXynSL4) was highly active and stable over the neutral and alkaline pH range from 6 to 11, with maximum activity at pH 7 and more than 60% activity at pH 11. It had an apparent temperature optimum of 70oC and retained stable at this temperature in the presence of substrate. rXynSL4 was highly halotolerant, retaining more than 55% activity with 0.25.3.0 M NaCl and was stable at the concentration of NaCl up to 4M. The enzyme activity was significantly enhanced by β-mercaptoethanol and Ca2+ but strongly inhibited by heavy-metal ions and SDS. This thermophilic and alkaline- and salt-tolerant enzyme has great potential for basic research and industrial applications.

Effect of Collagen Peptide-Chelated Zinc Nanoparticles From Pufferfish Skin on Zinc Bioavailability in Rats

Honghui Guo,Yun-yun Chen,Zhuan Hong,Yiping Zhang,Quanling Xie,Hui Chen 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.9

Small-molecular-weight collagen peptides (CPs) with high zinc-chelating ability were extracted from pufferfish skin. Chelation of CPs with zinc was performed to prepare novel CP-chelated zinc (CP-Zn) nanoparticles. CP-Zn nanoparticles were spherical, regular, and well dispersed with an average size of ∼100 nm. The zeta potential assay was used to explore the stability of CP-Zn nanoparticles. CP-Zn nanoparticles were much more stable in the pH range of 3–8. The structural properties of CP-Zn nanoparticles were characterized by matrix-assisted laser desorption–ionization time-of-flight mass spectrometry, Fourier transform infrared spectroscopy, and 1H nuclear magnetic resonance spectroscopy. The results indicated that CPs were chelated with Zn ions through the amino nitrogen and oxygen atoms from the carboxyl groups. Furthermore, the animal experiment results showed that CP-Zn nanoparticles were more effective in improving zinc bioavailability of Zn-deficient rats than zinc gluconate and zinc sulfate. The study demonstrated that CP-Zn nanoparticles were ideal for zinc supplementation.

The basic helix–loop–helix transcription factors in the Colorado potato beetle Leptinotarsa decemlineata

Kai-Yun Fu,Qing-Wei Meng,Feng-Gong Lüa,Wen-Chao Guo,Tursun Ahmat,Guo-Qing Li 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.2

The basic helix–loop–helix (bHLH) transcription factors possess crucial functions in cell proliferation, determination, differentiation, cell cycle maintenance and homeostasis or stress response pathways. Since a few juvenile hormone analogues such as hydroprene, methoprene and pyriproxyfen targeting a bHLH member Met are already registered for pest management, there is a potential to develop more insecticides targeting various bHLHs. The identification of bHLH members is the first step. Based on the transcriptome and the genome of the Colorado potato beetle Leptinotarsa decemlineata, the most important pest in potato, 49 bHLH members were identified. All LdbHLH memberswere defined by their names and families according to various phylogenetic analyses with bHLH homologues of Drosophila melanogaster, Apis mellifera, Bombyx mori and Tribolium castaneum. Among these LdbHLHs, 17, 10, 10, 1, 10 and 1 members belonged to A, B, C, D, E and F high-order groups, respectively. The results would provide useful background information for future studies on functions of bHLH proteins in the regulation of L. decemlineata development. Moreover, the bHLHs could serve as potential insecticide targets. These proteins could be used in small molecule screen, or in the development of RNAi-based pest management methods.

Identification and sex expression profiles of olfactory-related genes in Mythimna loreyi based on antennal transcriptome analysis

Zhang Yun-Ying,Guo Jin-Meng,Wei Zhi-Qiang,Zhang Xiao-Tong,Liu Si-Ruo,Guo Hui-Fang,Dong Shuanglin 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.3

To better understand the olfactory mechanism of Mythimna loreyi, a worldwide migratory pest, we for the first time conducted a large scale identification of olfactory-related genes and investigation of their sex expression profiles by transcriptomic analysis. A total of 42,832 unigenes were obtained by transcriptome sequencing, as sembly and annotation, with an average length of 1,229 bp and N50 of 2,086 bp. In particular, 138 olfactoryrelated genes were identified by homologous blasting, including 33 odorant binding proteins (OBPs), 16 che mosensory proteins (CSPs), 63 odorant receptors (ORs), 24 ionotropic receptors (IRs) and two sensory neuron membrane proteins (SNMPs). Further, by using differential gene expression (DGE) and fragments per kilobase per million fragments (FPKM) values to compare the transcript levels between female and male antennae, we found that 22 olfactory-related genes (9 OBPs, one CSP and 12 ORs) were sex biased, with 10 genes being male biased and 12 genes female biased. In addition, sex and tissue expression profiles determined by qPCR of 15 selected genes confirmed the reliability of sex expression profiles obtained by the transcriptomic analysis, and demonstrated that most olfactory-related genes were specifically or primarily expressed in antennae, suggesting their roles in olfaction, while a few genes were highly expressed in other tissues, implying their non-olfaction functions. This study provides an important basis for further functional study of olfactory genes in M. loreyi.

Identification and sex expression profiles of olfactory-related genes in Mythimna loreyi based on antennal transcriptome analysis

Zhang Yun-Ying,Guo Jin-Meng,Wei Zhi-Qiang,Zhang Xiao-Tong,Liu Si-Ruo,Guo Hui-Fang,Dong Shuanglin 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.2

To better understand the olfactory mechanism of Mythimna loreyi, a worldwide migratory pest, we for the first time conducted a large scale identification of olfactory-related genes and investigation of their sex expression profiles by transcriptomic analysis. A total of 42,832 unigenes were obtained by transcriptome sequencing, as sembly and annotation, with an average length of 1,229 bp and N50 of 2,086 bp. In particular, 138 olfactoryrelated genes were identified by homologous blasting, including 33 odorant binding proteins (OBPs), 16 che mosensory proteins (CSPs), 63 odorant receptors (ORs), 24 ionotropic receptors (IRs) and two sensory neuron membrane proteins (SNMPs). Further, by using differential gene expression (DGE) and fragments per kilobase per million fragments (FPKM) values to compare the transcript levels between female and male antennae, we found that 22 olfactory-related genes (9 OBPs, one CSP and 12 ORs) were sex biased, with 10 genes being male biased and 12 genes female biased. In addition, sex and tissue expression profiles determined by qPCR of 15 selected genes confirmed the reliability of sex expression profiles obtained by the transcriptomic analysis, and demonstrated that most olfactory-related genes were specifically or primarily expressed in antennae, suggesting their roles in olfaction, while a few genes were highly expressed in other tissues, implying their non-olfaction functions. This study provides an important basis for further functional study of olfactory genes in M. loreyi.

An Aqueous Extract of Yunnan Baiyao Inhibits the Quorum-Sensing-Related Virulence of Pseudomonas aeruginosa

Zu-Guo Zhao,Shuang-Shuang Yan,Yun-Mei Yu,Na Mi,La-Xi Zhang,Jun Liu,Xiao-Ling Li,Fang Liu,Jun-Fa Xu,Wei-Qing Yang,Guo-Ming Li 한국미생물학회 2013 The journal of microbiology Vol.51 No.2

Yunnan Baiyao is a famous Chinese medicine that has long been directly applied to wounds to reduce bleeding, pain, and swelling without causing infection. However, little is known about its ability to prevent infection. The present study aimed to assess in vitro the anti-virulence activity of an aqueous extract of Yunnan Baiyao (YBX) using Pseudomonas aeruginosa as a pathogenic model. We found that a sub-MIC (2.5 mg/ml) of YBX can efficiently interfere with the quorum-sensing (QS) signaling circuit. Real-time polymerase chain reaction analysis showed that a sub-MIC of YBX downregulated the transcriptions of lasR, lasI, rhlR, and rhlI,which resulted in global attenuation of QS-regulated virulence activities, such as biofilm formation, and secretion of LasA protease, LasB elastase and pyocyanin. Further, YBX reduced the motility of P. aeruginosa related to QS, and impaired the formation of biofilms. These results suggest that YBX may possess global inhibitory activity against the virulence of P. aeruginosa and that YBX may also exhibit antimicrobial activity in vivo. The present study suggests that Yunnan Baiyao represents a potential source for isolating novel, safe, and efficacious antimicrobial agents.