Very long life fatigue behaviors of 16Mn steel and welded joint

Yongjie Liu,Chao He,Chongxiang Huang,Muhammad K. Khan,Qingyuan Wang 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.5

Very long life fatigue tests were carried out on 16Mn steel base metal and its welded joint byusing the ultrasonic fatigue testing technique. Specimen shapes (round and plate) were considered for both the base metal and welded joint. The results show that the specimens present different S-N curve characteristics in the region of 105-109 cycles. The round specimens showed continuously decreasingtendency while plate specimens showed a steep decreasing step and an asymptotic horizontal one. The fatigue strength of round specimen was found higher than plate specimen. The fatigue strength of as-welded joint was 45.0% of the base material for butt joint and 40% for cruciform as-welded joint. It was found that fracture can still occur in butt joint beyond 5×106 cycles. The cruciform joint has a fatigue limit in the very long life fatigue regime (107-109 cycles). Fatigue strength of butt as-welded joint was much higher as compared to cruciform as-welded joint. Improvement in fatigue strength of welded joint was found due to UPT. The observation of fracture surface showed crack mainly initiated from welded toe at fusion areas or geometric discontinuity sites at the surface in butt joint and from welded toe in cruciform joint.

Very long life fatigue behaviors of 16Mn steel and welded joint

Liu, Yongjie,He, Chao,Huang, Chongxiang,Khan, Muhammad K.,Wang, Qingyuan Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.5

Very long life fatigue tests were carried out on 16Mn steel base metal and its welded joint by using the ultrasonic fatigue testing technique. Specimen shapes (round and plate) were considered for both the base metal and welded joint. The results show that the specimens present different S-N curve characteristics in the region of $10^5-10^9$ cycles. The round specimens showed continuously decreasing tendency while plate specimens showed a steep decreasing step and an asymptotic horizontal one. The fatigue strength of round specimen was found higher than plate specimen. The fatigue strength of as-welded joint was 45.0% of the base material for butt joint and 40% for cruciform as-welded joint. It was found that fracture can still occur in butt joint beyond $5{\times}10^6$ cycles. The cruciform joint has a fatigue limit in the very long life fatigue regime ($10^7-10^9$ cycles). Fatigue strength of butt as-welded joint was much higher as compared to cruciform as-welded joint. Improvement in fatigue strength of welded joint was found due to UPT. The observation of fracture surface showed crack mainly initiated from welded toe at fusion areas or geometric discontinuity sites at the surface in butt joint and from welded toe in cruciform joint.

Optimization of bayberry juice spray drying process using response surface methodology

Yongji Liu,Fengxia Chen,Honghui Guo 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.5

In this study, thirteen different runs according to the central composite design-response surface methodology were used to optimize the quality parameters of spray-dried bayberry juice powder. The independent variables were different levels of inlet air temperature (145.8–174.1 °C) and maltodextrin concentration (22.9–37.0%). The responses were process yield, moisture content, hygroscopicity, glass transition temperature (Tg), total color difference (ΔE), redness, retention of phenolics and anthocyanins, and antioxidant capacity. The optimum operation conditions for the highest Tg, redness, anthocyanins retention and antioxidant capacity with the lowest ΔE and hygroscopicity were obtained at inlet drying temperature of 150 °C and maltodextrin concentration of 31%. This study revealed that by applying these optimal conditions, bayberry juice powder with a 74.16% yield, 3.15% moisture content, 10.25% hygroscopicity, 41.15 °C Tg, 24.74 ΔE, 27.45 Hunter a redness, 89.55% anthocyanins retention, 77.71% phenolics retention, and 30.19 mmol Trolox equivalents/g antioxidant capacity was produced.

Low-temperature sintering of KNN with excess alkaline elements and the study of its ferroelectric domain structure

Yongjie Zhao,Rongxia Huang,Rongzheng Liu,Heping Zhou,Wei Zhao 한국물리학회 2013 Current Applied Physics Vol.13 No.9

In the present work, lead-free K0.48Na0.52NbO3 (KNN) ceramics were synthesized by conventional ceramicsprocesses. The excess 3.3 mol% Na2CO3 and 1.1 mol% K2CO3 were added to decrease the sinteringtemperature to 990 ℃ and effectively promote the densification of KNN ceramics. X-ray diffraction resultsindicated that the excess Na2CO3 and K2CO3 would induce the formation of the A-site riched secondaryphase with the sintering temperature. Compositional segregation phenomenon enhanced bydifferent sintering temperature, spurs the formation of secondary phase in KNN-AEe ceramics. Inaddition, the difference between ferroelectric domain structure of the poled and as-sintered KNN-AEesamples for 990 ℃ was investigated. Via XRD analysis and SEM observation, it was found that the domainorientation was urged during the poling process.

Cell proliferation can be modulated by receptor tyrosine kinase-like orphan receptor 2 in the silkworm, Bombyx mori

Yongjie Feng,Wei Liu,Dhiraj Kumar,Min Zhu,Renyu Xue,Guangli Cao,Xiaolong Hu,Chengliang Gong 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.4

The receptor tyrosine kinase-like orphan receptor 2 (Ror2) is involved in the Wnt/β-catenin signaling pathway which regulates cell proliferation, polarity, differentiation, migration, metabolism and survival. However, the function of Ror2 in the silkworm Bombyx mori is still undisclosed. In the present investigation, we have made an effort to clone the silkworm Ror2 gene (BmRor2). The sequence analysis showed that the open reading frame (ORF) was 1914 bp in size and encoded a protein with the conserved domains of Ror2 protein. The qRT-PCR results indicated that the BmRor2 gene expression level was the highest in the head among all identified tis sues on 3rd day of the fifth instar larvae. In the gonads of the different development stages, the BmRor2 gene expression level was highest on the 4th day of the fourth instar larvae. The immunofluorescence assay indicated that the BmRor2 protein was located at the cytomembrane. The effects of BmRor2 protein on the expression levels of genes related to TGF-β, Hippo, JAK-STAT and Notch signaling pathways were investigated by qRT-PCR. The expression levels of crumbs (crb), warts (wts), α-catenin (cat), four-jointed (fj), decapentaplegic (dpp), kibra ortholog (kibra), serrate (serr) and c-myc (myc) genes were down-regulated, whereas, suppressor of cytokine signaling 2 (socs 2) gene expression was up-regulated in the cultured BmN cells after the BmRor2 expression level was up-regulated. Further, cell proliferation was demoted and the size of cells was decreased when BmRor2 expression level was elevated. Our current finding recommended that BmRo2 can regulate TGF- β, Hippo, JAKSTAT, and Notch signaling pathways, and affect cell proliferation and size.

Separation of valuable metals from mixed cathode materials of spent lithium-ion batteries by single-stage extraction

Yongjie Li,Qiang Fu,Hongyun Qin,Kun Yang,Junnan Lv,Qicheng Zhang,Zhang Hui,Feng Liu,Xia Chen,Ming Wang 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.10

With the intensity of resource scarcities and environmental problems, the disposal and recovery of spent lithium-ion batteries, especially recovery of valuable metals, becomes vital. In this work, a method of co-extracting nickel, cobalt, manganese and being separated from lithium by single-stage solvent extraction is proposed. The extraction and separation process of D2EHPA was studied. The effects of extractant concentration, saponification percentage, extraction time and O:A on the extraction efficiency of D2EHPA were systematically studied. Nearly 100% manganese, 94% cobalt and about 90% nickel were co-extracted and separated from lithium using D2EHPA in kerosene by single-stage extraction. The maximum value of separation factors (Ni/Li, Co/Li and Mn/Li) was 13.03, 23.42 and 1904.24. The mathematical model of extraction of four ions was developed by combination of Levenberg-Marquardt method and Universal Global Optimization method. The proposed extraction model accurately fits the experimental data and helps to predict the extraction efficiency of each metal under the corresponding conditions.

Reliable Localization for Wireless Sensor Networks in Complex Environments

Xiaolei Liu,Yongji Ren,Xuguang Xin,Liping Zhang,Jixiang Chen 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10

Although localization has been widely studied for Wireless Sensor Networks (WSNs), the complex environments and the large network scale pose severe challenges and make it necessary to develop new reliable localization algorithms. In this paper, we propose a novel Multi-Hop Localization Algorithm for large-scale WSNs in complex environments. This work is based on the consideration that the localization process would encounter several kinds of adverse factors with different nature at the same time (e.g. anisotropic network characteristics, ranging uncertainty, link quality of multihop paths, etc.), which lead to obvious degradation of localization performance. Unlike most of the existing schemes, we transform the localization problem in complex environments into a hybrid constraint satisfaction problem (CSP) which is composed of three different kinds of constraints, i.e. spatial constraint, network situation constraint, and confidence constraint. Set-membership approach and interval analysis method have been utilized to deal with the CSP and determine the positions of sensor nodes. Simulation results show that our scheme is an effective and efficient approach to localization in large-scale WSNs.

Transient propagation of BmLV and dysregulation of gene expression in nontarget cells following BmLV infection

Feng Yongjie,Zhang Xing,Kumar Dhiraj,Kuang Sulan,Liu Bo,Hu Xiaolong,Zhu Min,Liang Zi,Cao Guangli,Xue Renyu,Gong Chengliang 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Bombyx mori latent virus (BmLV), a novel positive-strand RNA virus was first identified in the B. mori cultured BmN cell line. Whether the infectivity of BmLV to silkworm larvae and non-silkworm cells is connected with dysregulation of gene expression are not well understood. A complete sequence of BmLV genomic RNA was identified and revealed that a fragment with 495 nt in length was deleted from the RNA-dependent RNA poly merase (RdRp) gene in some BmLV genomic RNAs. Studies on the infectivity of BmLV to nontarget cells showed that BmLV can infect silkworm larvae, Spodoptera frugiperda Sf-9 and H1299 lung cancer cells with transient propagation. The dysregulation of gene expression of Sf-9 cells followed by BmLV infection was analyzed. Out of 743 differentially expressed genes (DEGs), 300 were upregulated and 443 were downregulated. Gene Ontology (GO) analysis indicated the DEGs were enriched into oxidoreductase activity for CH-NH 2 group donors, gluta mate biosynthetic process, response to stress and proteasome core complex. KEGG enrichment analysis showed that DEGs were mainly enriched into sulfur metabolism, RNA degradation, proteasome, pentose and glucuronate interconversions. Undesirable nutrients and temperature factors contributed to the propagation of BmLV in Sf-9 cells. Additionally, the Imd and RNAi pathways were activated by BmLV infection without stimulating Toll and JAK-STAT pathways. Therefore, it is suggested that BmLV is originated from plants, which can enter nontarget cells with transient propagation. The transient infection of BmLV may not only be regulated by Imd and RNAi immune pathways but also mediated by dysregulation of gene expression.

Integrated analysis of transcriptome and milk metagenome in subclinical mastitic and healthy cows

Zhang Jinning,Liu Xueqin,Usman Tahir,Tang Yongjie,Mi Siyuan,Li Wenlong,Yang Mengyou,Yu Ying 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.4

Objective: Abnormally increased somatic cell counts (SCCs) in milk is usually a sign of bovine subclinical mastitis. Mutual interaction between the host and its associated microbiota plays an important role in developing such diseases. The main objective of this study was to explore the difference between cows with elevated SCCs and healthy cattle from the perspective of host-microbe interplay. Methods: A total of 31 milk samples and 23 bovine peripheral blood samples were collected from Holstein dairy cattle to conduct an integrated analysis of transcriptomic and metagenomics. Results: The results showed that Ralstonia and Sphingomonas were enriched in cows with subclinical mastitis. The relative abundance of the two bacteria was positively correlated with the expression level of bovine transcobalamin 1 and uridine phosphorylase 1 encoding gene. Moreover, functional analysis revealed a distinct alternation in some important microbial biological processes. Conclusion: These results reveal the relative abundance of Ralstonia and Sphingomonas other than common mastitis-causing pathogens varied from healthy cows to those with subclinical mastitis and might be associated with elevated SCCs. Potential association was observed between bovine milk microbiota composition and the transcriptional pattern of some genes, thus providing new insights to understand homeostasis of bovine udder.

Sublethal and transgenerational effects of six insecticides on Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

Li Jianying,Liu Jin,Chi Baojie,Chen Peng,Liu Yongjie 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.2

To clarify the effects of sublethal concentration of insecticide on the growth, development and reproduction of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), the sublethal and transgenerational effects of the LC 30 of six insecticides on adults and progeny (F 1 and F 2 generations) were studied using age-stage, two-sex life tables. Exposure to six insecticides had significant negative impacts on the life-history traits of B. dorsalis and led to reduced adult longevity and fecundity in F 0 , a longer larval stage duration in F 1 , and reduced fertility and survival. The intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R 0 ) were reduced in F 1 , with the greatest reduction observed in the chlorpyrifos treatment. In the F 2 generation, the adverse effects were weakened, only the cyantraniliprole treatment had lower values than the control, and the fecundity of other treatments returned to normal. Obvious “hormesis” phenomena were not observed in any of the generations. Based on the population hazard index, chlorpyrifos had the best control effect in the early stage, and cyan traniliprole had the best control effect in the long term. These results indicate that the LC 30 of the six insecticides exert different transgenerational effects on the B. dorsalis population.