The Flow Behavior and Forming Limit Modeling of an Al- Cu-Mg Aluminum Alloy Sheet Considering the Effects of Pre-Strain and Solution Heat Treatment

Xiao-Qiang Li,Gui-Qiang Guo,Hong-Zhi Gao,Nan Song,Dong-Sheng Li 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

Al-Cu-Mg aluminum alloy sheet is widely used for aircraft skin. Multi-stage forming combined with Solution Heat Treatment (SHT) is necessary for some geometrically complex productions in aircraft skin components. However, the effects of pre-strain and natural ageing time on the formability of Al-Cu-Mg aluminum alloy sheet are not fully understood. In this study, the deformation responses of an Al-Cu-Mg aluminum alloy sheet, over a range of pre-strain levels (0% to 6%) and natural ageing time levels (0 h to 2 h) were investigated. A modified Hollomon constitutive model coupling with pre-strain and natural ageing time was proposed to characterize the deformation responses of the Al-Cu-Mg aluminum alloy sheet. The hemispherical dome tests were performed at natural ageing time levels ranging from 0.25 h to 1.5 h. Marciniak and Kuczynski (M-K) theory was used to obtain the forming limit prediction model which takes pre-strain and natural ageing time into account. The theoretical Forming Limit Curves (FLCs) were compared with the experimental results.

Antioxidant, Antimutagenic, and In vivo Buccal Mucosa Cancer Preventive Effects of Fructus Malvae

Gui-Jie Li,Qiang Wang,Yu Qian,Xin Zhao 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.4

Fructus Malvae is functional food known forantioxidant, anti-mutagenic, and in vivo anticancer effects. Fructus Malvae extracts demonstrated high antioxidantactivities in DPPH and hydroxyl radical scavenging activityassays. In an Ames mutagenicity test, Fructus Malvaeexhibited antimutagenicty in association with MNNG (Nmethyl-N'-nitro-N-nitrosoguanidine) in Salmonella TyphimuriumTA100 cells. U14 squamous carcinoma cells were injectedinto the buccal mucosa of KM (Kunming) mice. Thewound at the injection site was smeared with a FructusMalvae solution, which was also administered to mice bygavage. Tumor volumes were reduced and tissue sectionanalysis of buccal mucosa cancer and cervical lymph nodetissues showed anti-cancer effects in Fructus Malvaetreated groups. Fructus Malvae possesses good antioxidantand antimutagenic activities and exerts a preventive effectagainst buccal mucosa cancer in vivo.

United Electromagnetic Characteristics and Online Monitoring Method of Static Air-gap Eccentricity of Turbo-Generator

Gui-Ji Tang,Meng-Qiang Ke,Yu-Ling He,Fa-Lin Wang 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

The purpose of this paper is to investigate the united Electromagnetic characteristics for the effective monitoring on the static air-gap eccentricity (SAGE) of turbo-generator. Different from other studies, this paper not only studies on the unbalanced magnetic pull (UMP) and the vibration characteristics of the stator and the rotor, but also investigates the harmonic features of the magnetic flux density and the circulating current inside the parallel branches (CCPB). The theoretical calculation, together with the finite-element-method (FEM) simulation and the experiment verification, is taken for a SDF-9 type non-salient generator. It is shown that, when SAGE occurs, apparent doublefrequency UMP and vibrations will be produced both on the stator and the rotor, while the CCPB will have an obvious increment at the 1<SUP>st</SUP> harmonic component. In addition, the amplitude of the magnetic flux density will be of cosine distribution in the circumferential position of the air-gap, while in normal condition it is a constant. Moreover, the pass-band amplitude, together with the 1<SUP>st</SUP> harmonic of the magnetic flux density, will be enlarged as well. These united electromagnetic characteristics can be used as the diagnosis and monitoring criterion for SAGE.

Three-Dimensional Seismic Isolation Study of Single-Layer Reticulated Domes by Parameter Analysis

Gui-Bo Nie,Dong-fang Li,Xudong Zhi,Qiang Chen,Fuyang Wang 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.6

Spatial structures, represented by reticulated domes, have developed rapidly in the last several decades due to their reasonable mechanical properties and beautiful structural shape. However, several spatial structure collapses have occurred during the recent frequent earthquakes in China, especially the 2013 Lushan earthquake. These collapses have altered the traditional understanding that the spatial structure has good seismic performance. Real seismic damage cases reveal that a spatial structure in a severe earthquake zone with unreasonable seismic design cannot maintain its functional characteristics; therefore, there is an urgent need for improvements to enhance the seismic performance of spatial structures. This paper proposes a new three-dimensional isolation spring support (TISS). To study the mechanical properties of this support, corresponding experiments were performed, and the constitutive relation of this support was investigated. A simplifi ed fi nite element model of the new TISS was defi ned in ABAQUS to conduct a seismic isolation study of single-layer reticulated domes. And then the infl uence of diff erent parameters on the seismic isolation performance of the TISS was analysed. The parameter analysis results indicated that friction plays an important role in the mechanical properties of the support and thus causes diff erent seismic isolation eff ects under small earthquakes and severe earthquakes. At the same time, because of the design concept of the support, a non-linear relation exists between the seismic isolation eff ect and stiff ness such that under severe earthquakes. On the other hand, the TISS also has preferable isolation performance on the defective reticulated domes. Therefore, the three-dimensional isolation support presented in this paper has preferable application prospects and potential economic benefi ts that could be applied extensively in the three-dimensional isolation area of spatial structures. In addition, the numerical analysis procedure based on ABAQUS can be used to accurately analyse the isolation property and to lay the foundation for the practical function of isolation supports and the seismic design of structures.

Prevalence and Genotype Distribution of Human Papillomavirus Infections in Women Attending Hospitals in Chaozhou of Guangdong Province

Chen, Qiang,Luo, Zhao-Yun,Lin, Min,Lin, Qi-Li,Chen, Chan-Yu,Yang, Chun,Xie, Long-Xu,Li, Hui,Zheng, Jia-Kun,Yang, Li-Ye,Ju, Gui-Zhi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Background: Human papillomavirus (HPV) infection is the main cause of cervical cancer. Limited epidemiologic data of HPV prevalence are available for women attending hospitals in southern China. This study aimed to evaluate the profiles of HPV infection and cytology status in gynecological outpatients in Chaozhou City. Methods: A total of 2833 eligible women were enrolled. The HPV GenoArray test was used for HPV detection and genotyping. Nearly one half of the HPV positive women received liquid-based cytology test. Logistic regression analysis was performed to assess the predictable effects of age and genotype for categories of abnormal cytology. Results: The prevalence of overall, high-risk, and low-risk HPV infection were 24.5%, 19.5% and 8.4%, respectively. A U-shaped age-specific prevalence curve was observed in overall HPV and high-risk HPV, but not in low-risk HPV, which declined with age increasing. The 6 most common high-risk HPV type in descending order, were types 52, 16, 58, 18, 68, and 33. Age and HPV genotype were both important determinants of abnormal cytology incidence, the older women (>45 years) and those infected with HPV type 16 and/or 18 having the highest risk for abnormal cytology. Conclusion: Our findings support the hypothesis that second-generation HPV prophylactic vaccines including HPV-52 and -58 may offer higher protection for women residing in Chaozhou and neighboring cities in Guangdong.

United Electromagnetic Characteristics and Online Monitoring Method of Static Air-gap Eccentricity of Turbo-Generator

Tang, Gui-Ji,Ke, Meng-Qiang,He, Yu-Ling,Wang, Fa-Lin The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

The purpose of this paper is to investigate the united Electromagnetic characteristics for the effective monitoring on the static air-gap eccentricity (SAGE) of turbo-generator. Different from other studies, this paper not only studies on the unbalanced magnetic pull (UMP) and the vibration characteristics of the stator and the rotor, but also investigates the harmonic features of the magnetic flux density and the circulating current inside the parallel branches (CCPB). The theoretical calculation, together with the finite-element-method (FEM) simulation and the experiment verification, is taken for a SDF-9 type non-salient generator. It is shown that, when SAGE occurs, apparent double-frequency UMP and vibrations will be produced both on the stator and the rotor, while the CCPB will have an obvious increment at the $1^{st}$ harmonic component. In addition, the amplitude of the magnetic flux density will be of cosine distribution in the circumferential position of the air-gap, while in normal condition it is a constant. Moreover, the pass-band amplitude, together with the $1^{st}$ harmonic of the magnetic flux density, will be enlarged as well. These united electromagnetic characteristics can be used as the diagnosis and monitoring criterion for SAGE.

Immunization of BALB/c mice with Brucella abortus 2308DwbkA confers protection against wild-type infection

Zhi-qiang Li,Dan Gui,Zhi-hua Sun,Jun-bo Zhang,Wen-zhi Zhang,Hui Zhang,Fei Guo,Chuangfu Chen 대한수의학회 2015 Journal of Veterinary Science Vol.16 No.4

Brucellosis is a zoonotic disease that causes animal and human diseases. Vaccination is a major measure for prevention of brucellosis, but it is currently not possible to distinguish vaccinated animals from those that have been naturally infected. Therefore, in this study, we constructed the Brucella (B.) abortus 2380 wbkA mutant (2308DwbkA) and evaluated its virulence. The survival of 2308DwbkA was attenuated in murine macrophage (RAW 264.7) and BALB/c mice, and it induced high protective immunity in mice. The wbkA mutant elicited an anti-Brucella-specific immunoglobulin G response and induced the secretion of gamma interferon. Antibodies to 2308DwbkA could be detected in sera from mice, implying the potential for use of this protein as a diagnostic antigen. The WbkA antigen would allow serological differentiation between infected and vaccinated animals. These results suggest that 2308DwbkA is a potential attenuated vaccine against 16M. This vaccine will be further evaluated in sheep.

Toward Full Spectrum Speciation of Silver Nanoparticles and Ionic Silver by On-Line Coupling of Hollow Fiber Flow Field-Flow Fractionation and Minicolumn Concentration with Multiple Detectors

Tan, Zhi-Qiang,Liu, Jing-Fu,Guo, Xiao-Ru,Yin, Yong-Guang,Byeon, Seul Kee,Moon, Myeong Hee,Jiang, Gui-Bin American Chemical Society 2015 ANALYTICAL CHEMISTRY - Vol.87 No.16

<P>The intertransformation of silver nanoparticles (AgNPs) and ionic silver (Ag(I)) in the environment determines their transport, uptake, and toxicity, demanding methods to simultaneously separate and quantify AgNPs and Ag(I). For the first time, hollow fiber flow field-flow fractionation (HF5) and minicolumn concentration were on-line coupled together with multiple detectors (including UV–vis spectrometry, dynamic light scattering, and inductively coupled plasma mass spectrometry) for full spectrum separation, characterization, and quantification of various Ag(I) species (<I>i.e</I>., free Ag(I), weak and strong Ag(I) complexes) and differently sized AgNPs. While HF5 was employed for filtration and fractionation of AgNPs (>2 nm), the minicolumn packed with Amberlite IR120 resin functioned to trap free Ag(I) or weak Ag(I) complexes coming from the radial flow of HF5 together with the strong Ag(I) complexes and tiny AgNPs (<2 nm), which were further discriminated in a second run of focusing by oxidizing >90% of tiny AgNPs to free Ag(I) and trapped in the minicolumn. The excellent performance was verified by the good agreement of the characterization results of AgNPs determined by this method with that by transmission electron microscopy, and the satisfactory recoveries (70.7–108%) for seven Ag species, including Ag(I), the adduct of Ag(I) and cysteine, and five AgNPs with nominal diameters of 1.4 nm, 10 nm, 20 nm, 40 nm, and 60 nm in surface water samples.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2015/ancham.2015.87.issue-16/acs.analchem.5b01827/production/images/medium/ac-2015-01827q_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac5b01827'>ACS Electronic Supporting Info</A></P>

Expression of Connexin 43 and E-cadherin Protein and mRNA in Non-small Cell Lung Cancers in Chinese Patients

Zhao, Jun-Qiang,Sun, Fang-Jie,Liu, Shan-Shan,Yang, Jun,Wu, Yu-Quan,Li, Gui-Shan,Chen, Qing-Yong,Wang, Jia-Xiang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Aim: Connexin 43 (Cx43) and E-cadherin are important biomarkers related with cancer. Their expression at protein and mRNA levels was here investigated in 50 primary lung carcinoma tissues and 20 samples of adjacent normal tissue of Chinese patients with non-small cell lung cancer (NSCLC). Methods: Protein and mRNA expression were evaluated by ABC immunohistochemistry and RT-PCR. Results: (1) The positive expression rates of Cx43 and E-cadherin protein were higher in the adjacent normal tissues than those in the primary lung carcinoma tissues; (2) the positive expression rates of Cx43 and E-cadherin protein decreased with NSCLC progression; (3) the expression of E-cadherin protein was not related with the pathological type of NSCLC; and (4) the relative quantity of the Cx43 or E-cadherin mRNA expression was correlated with the the histological type, clinical stage, cancer cell differentiation and the lymph node metastasis. Conclusion: The data suggested that the Cx43 and E-cadherin are reduced with NSCLC progression, and might be important biomarkers for judging the metastasis and prognosis.

Effect of 5-aza-2'-deoxycytidine on Cell Proliferation of Non-small Cell Lung Cancer Cell Line A549 Cells and Expression of the TFPI-2 Gene

Dong, Yong-Qiang,Liang, Jiang-Shui,Zhu, Shui-Bo,Zhang, Xiao-Ming,Ji, Tao,Xu, Jia-Hang,Yin, Gui-Lin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

Objective: The present study employed 5-aza-2'-deoxycytidine (5-Aza-CdR) to treat non-small cell lung cancer (NSCLC) cell line A549 to investigate the effects on proliferation and expression of the TFPI-2 gene. Methods: Proliferation was assessed by MTT assay after A549 cells were treated with 0, 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR, a specific demethylating agent, for 24, 48 and 72h. At the last time point cells were also analyzed by flow cytometry (FCM) to identify any change in their cell cycle profiles. Methylation-specific polymerase chain reaction (MSPCR), real time polymerase chain reaction(real-time PCR) and western blotting were carried out to determine TFPI-2 gene methylation status, mRNA expression and protein expression. Results: MTT assay showed that the growth of A549 cells which were treated with 5-Aza-CdR was significantly suppressed as compared with the control group (0 ${\mu}mol/L$ 5-Aza-CdR). After treatment with 0, 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR for 72h, FCM showed their proportion in G0/G1 was $69.7{\pm}0.99%$, $76.1{\pm}0.83%$, $83.8{\pm}0.35%$, $95.5{\pm}0.55%$ respectively (P<0.05), and the proportion in S was $29.8{\pm}0.43%$, $23.7{\pm}0.96%$, $15.7{\pm}0.75%$, $1.73{\pm}0.45%$, respectively (P<0.05), suggesting 5-Aza-CdR treatment induced G0/G1 phase arrest. MSPCR showed that hypermethylation in the promoter region of TFPI-2 gene was detected in control group (0 ${\mu}mol/L$ 5-Aza-CdR), and demethylation appeared after treatment with 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR for 72h. Real-time PCR showed that the expression levels of TFPI-2 gene mRNA were $1{\pm}0$, $1.49{\pm}0.14$, $1.86{\pm}0.09$ and $5.80{\pm}0.15$ (P<0.05) respectively. Western blotting analysis showed the relative expression levels of TFPI-2 protein were $0.12{\pm}0.01$, $0.23{\pm}0.02$, $0.31{\pm}0.02$, $0.62{\pm}0.03$ (P<0.05). TFPI-2 protein expression in A549 cells was gradually increased significantly with increase in the 5-Aza-CdR concentration. Conclusions: TFPI-2 gene promoter methylation results in the loss of TFPI-2 mRNA and protein expression in the non-small cell lung cancer cell line A549, and 5-Aza-CdR treatment could induce the demethylation of TFPI-2 gene promoter and restore TFPI-2 gene expression. These findings provide theoretic evidence for clinical treatment of advanced non-small cell lung cancer with the demethylation agent 5-Aza-CdR. TFPI-2 may be one molecular marker for effective treatment of advanced non-small cell lung cancer with 5-Aza-CdR.