Fatigue life prediction model of Ti-6Al-4V alloy forgings based on forging process parameters

Xiurong Fang,Jinhui Yang,Liu Liu,Ziliang Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

Forging processing parameters have an important impact on the fatigue resistance of metal in the process of plastic forming, which directly threatens the safety and reliability of the metal’s service. Taking Ti-6Al-4V alloy as the research object, this study investigates the effect of processing parameters, including forging temperature and deformation degree on the Young's modulus, ultimate tensile strength, and reduction of fracture area on the basis of the mechanical property testing of Ti-6Al-4V alloy forgings and obtains the regression equations at the same time. Combined with the existing stress fatigue life prediction formula, the fatigue life prediction based on forging process parameters is realized. Results show that forging temperature and deformation degree have a significant effect on fatigue life. The forging processing parameters of Ti-6Al-4V alloy with optimum fatigue life are as follows: 985 °C-990 °C forging temperature and 46 %-50 % deformation degree.

Contrast of sludge toxicity variation during treatment of wastewater containing mixed chlorophenols and single chlorophenol

Xiurong Chen,Yuan Wang,Qiuyue Li,Yingying Yang,Xiao Wei,Shanshan Wang,Quanlin Lu,Xiaoli Sun 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.5

To address problems associated with the potential toxicity of sludge when it is applied in land utilization, this study investigated the variations by which activated sludge becomes toxic when fed with wastewater containing mixed chlorophenols, and compared variations in sludge toxicity due to inputs of mixed chlorophenols and single chlorophenol groups. In this study, 4-chlorophenol (4-CP), 2,4,6-trichlorophenol (2,4,6-TCP) and mixed chlorophenols which consist of both 4-CP and 2,4,6-TCP were studied in sequencing batch reactors (SBR). The results indicate that in 0-30 d, the toxicity of sludge fed with mixed chlorophenols is higher than that of sludge fed with single chlorophenol groups. During 50-100 d, the toxicity of sludge fed with mixed chlorophenols ranged between two single chlorophenol groups. EPS and protein in EPS had a significant relationship with sludge toxicity, but there was no significant relationship between polysaccharide in EPS and sludge toxicity.

Association between Delayed Lactogenesis II and Early Milk Volume among Mothers of Preterm Infants

Xiurong Yu,Jianhua Li,Xiangyun Lin,Dandan Luan 한국간호과학회 2019 Asian Nursing Research Vol.13 No.2

Purpose: This study aimed to evaluate the effect of delayed lactogenesis Ⅱ on early milk volume in mothers expressing milk for their preterm infants. Methods: 142 mothers with preterm infants participated in a longitudinal cohort study, the milk volumes over 14 days postpartum between mothers with delayed lactogenesis Ⅱ ( 72 hours) and mothers with non-delayed lactogenesis Ⅱ(< 72 hours) were compared using Wilcoxon's rank sum tests. Results: The prevalence of delayed lactogenesisⅡ among mothers of preterm infants was 36.0% (36/100). There existed negative correlations between the onset of lactogenesis Ⅱ and the daily milk volumes( rs ¼ 0.525~0.354, p ¼ .002 ~ p < .001). The milk volumes in every 24-hour of the 14 days postpartum in delayed group were significantly less than that in non-delayed group (p ¼ .002 ~ p < .001). After controlling for the covariates, pregnancy-induced hypertension syndrome, delayed expression initiation, shorter daily sleeping time were found to be the risk factors for delayed lactogenesis Ⅱ. Conclusion: Delayed lactogenesis Ⅱ was associated with lower milk volume in early postpartum period. Women who were at risk for delayed lactogenesis Ⅱ need targeted interventions and additional support during pregnancy and postpartum.

Effect of Molybdate Conversion Coating of Magnesium Alloy Reinforced by Micro-arc Oxidation

Hongda Zhu,Xuetian Li,Xiurong Guan,Zhongcai Shao 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

In order to enhance the corrosion resistance of molybdate conversion coating, the molybdate coating is subjected to micro-arcoxidation treatment in electrolyte with Na2SiO3as a main salt. The electrochemical behavior and corrosion weight loss ofdifferent coating were studied. The surface morphology, element composition, roughness and phase composition of differentcoatings were analyzed by SEM, EDS, laser confocal microscopy and XRD, the growth process of different micro-arcoxidation coatings was explored. The results shows that the arcing voltage of the molybdate coating enhanced by micro-arcoxidation is significantly reduced, the corrosion potential is shifted to the right, and the corrosion weightlessloss of thecoating is the lowest, compared with the molybdate coating and the micro-arc oxidation coating. Micro-arc oxidation on thesurface of the molybdate coating is beneficial to the formation of MgAl2O4and the production of new phase is MoSi2,whichcan better improve the corrosion resistance of the molybdate coating. The micro-arc oxide coating does not form a ceramicfilm with a pore structure at the moment of arcing. As the micro-arc oxidation time prolongs, the ceramic film is graduallyformed. When the time reaches 60 s, the ceramic film is completely formed.

Cloning and characterization of hemerythrin gene from Sipuncula Phascolosoma esculenta

Yan Liu,Chenghua Li,Xiurong Su,Mengqian Wang,Yanyan Li,Ye Li,Taiwu Li 한국유전학회 2013 Genes & Genomics Vol.35 No.1

Hemerythrin is a non-heme respiratory protein involved in oxygen storage and transport in invertebrates. In the present study, the hemerythrin cDNA was cloned from Phascolosoma esculenta (denoted as PeHr) by PCR and rapid amplification of cDNA ends approaches. The full-length PeHr consisted of 770 bp containing of a 50-terminal untranslated region (UTR) of 83 bp, a 30-terminal UTR of 327 bp, and a coding domain sequence of 360 bp encoding a polypeptide of 120 amino acids with estimated molecular mass of 13.6 kDa and theoretical isoelectric point of 5.78. The expression profiles of PeHr were evaluated by real-time RT-PCR under blood loss stress. The expression level of PeHr was significantly up-regulated from 45 to 48 h, then slightly recovered to its original level. The coding sequence of the PeHr was cloned and expressed in Escherichia coli BL21 (DE3) for antibodies preparation. Western blotting analysis conformed that the generated antibodies could specifically identify not only recombinant product, but also native protein from the total protein extraction. Our results indicated that PeHr might be involved into haemocytes regeneration, and its function roles should be further investigated by the generated antibodies.

Simulation Research and Parameter Optimization for Hypoid Gear NC Machining

Hu Hong,Zhu xiurong 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.3

The paper studied hypoid gear CNC machining theory and simulation processing. Through construct a simulation case of hypoid gear machining system, optimization processing parameters for the main aspects, verify the effectiveness of pre-correction system.

Genome-Wide Identification and Functional Analysis of Long Non-coding RNAs in Sesame Response to Salt Stress

Gong Huihui,You Jun,Zhang Xiurong,Liu Yanzhong,Zhao Fengtao,Cui Xinxiao,Zhang Yujuan 한국식물학회 2021 Journal of Plant Biology Vol.64 No.6

Long non-coding RNAs (lncRNAs) play important roles in various biological regulatory processes in which complicated mechanisms are involved, as well as stress-responsive regulation. However, the number, characteristics, sequences and possible effects of lncRNAs in sesame response to salt stress are poorly understood. In this study, a total of 2482 lncRNAs were identified from two contrasting sesame genotypes under salt stress using high-throughput RNA sequencing, of which 599 were intergenic lncRNAs, 293 were antisense lncRNAs and 786 lncRNAs may encode proteins. Expression pattern analysis showed that most lncRNAs were expressed at a low level and a total of 700 differentially expressed lncRNAs were characterized as salt responsive in sesame. A large number of potential target genes of lncRNAs were predicted, and functional annotation analysis indicated that the differentially expressed lncRNAs in salt stress may regulate protein-coding genes involved in several important pathways related to glycolysis/gluconeogenesis, flavonoid biosynthesis, monoterpenoid biosynthesis, biotin metabolism, galactose metabolism, cyanoamino acid metabolism and carotenoid biosynthesis. Integrated analysis of lncRNAs and mRNAs revealed the regulatory role of lncRNAs associated with salt resistance in sesame, and provided convincing proof of the interplay of specific candidate target genes with lncRNAs. Our results indicated that a comprehensive set of lncRNAs with potential target genes were responsive to salt stress in sesame seedlings. These findings provided important information on salinity responses and adaptation of sesame to salt stress and may constitute useful resources for more comprehensive studies on gene regulation in sesame.

Invariance problem in structural non-probabilistic reliability index

Xinzhou Qiao,Linfan Song,Peng Liu,Xiurong Fang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.11

The non-probabilistic reliability index has been extensively used to evaluate the safety degree of structures with limited experiment data. By dealing the uncertain parameters of structures with the ellipsoidal model, this paper investigates the invariance problem in the nonprobabilistic reliability index. A prerequisite of the existence of the invariance problem is first given. An investigation of whether the two non-probabilistic first order reliability methods, namely the mean-value and design-point methods, encounter the same problem is then presented. A comparison of the precision of these two methods is further conducted through three numerical examples, and based on which some significant phenomena are summarized.

NMR-based metabolomics reveals the metabolite profiles of Vibrio parahaemolyticus under ferric iron stimulation

Jun Zhou,Chenyang Lu,Dijun Zhang,Chennv Ma,Xiurong Su 한국미생물학회 2017 The journal of microbiology Vol.55 No.8

Vibrio parahaemolyticus is a halophilic bacterium endemic to coastal areas, and its pathogenicity has caused widespread seafood poisoning. In our previous research, the protein expression of V. parahaemolyticus in Fe3+ medium was determined using isobaric tags for relative and absolute quantitation (iTRAQ). Here, nuclear magnetic resonance (NMR) was used to detect changes in the V. parahaemolyticus metabolome. NMR spectra were obtained using methanol-water extracts of intracellular metabolites from V. parahaemolyticus under various culture conditions, and 62 metabolites were identified, including serine, arginine, alanine, ornithine, tryptophan, glutamine, malate, NAD+, NADP+, oxypurinol, xanthosine, dCTP, uracil, thymine, hypoxanthine, and betaine. Among these, 21 metabolites were up-regulated after the stimulation of the cells by ferric iron, and 9 metabolites were down-regulated. These metabolites are involved in amino acid and protein synthesis, energy metabolism, DNA and RNA synthesis and osmolality. Based on these results, we conclude that Fe3+ influences the metabolite profiles of V. parahaemolyticus.

Characterization of Enterobacter cloacae under Phoxim Stress by Two-dimensional Gel Electrophoresis

Dijun Zhang,Jiajie Xu,Weina He,Qianqian Tong,Liping Chen,Jun Zhou,Xiurong Su 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.3

Phoxim, an organophosphorus pesticide, was widely used in agriculture but was banned because of its associated toxic runoff, which accumulated in surrounding water outlets. Here, Enterobacter cloacae was isolated from water outlets adjacent to industrial, agricultural and residential sewage having high organic phosphorus contents. To investigate the ability of E. cloacae to respond and survive under phoxim stress, both at the proteomic and transcriptional level, two-dimensional gel electrophoresis (2-DE), matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS/MS) and quantitative real-time PCR (qPCR) were used. A 2-DE analysis showed that 12 h post phoxim exposure, 46 proteins were differentially expressed and 21 protein spots were selected for MALDI-TOF-MS/MS identification. This resulted in the successful identification of 16 spots, nine up-regulated and seven down-regulated. Of these, stress response proteins, including the chaperone protein DnaK, GroEL, F0F1 ATP synthase subunit beta, phosphoenolpyruvate carboxykinase and outer membrane channel protein, were only expressed in the phoxim-treated experimental group. To validate these findings, seven genes were selected and positively confirmed using qPCR. The results suggest that the identified expression patterns relate to E. cloacae resistance and tolerance to high phoxim concentrations.