Dislocation Density-Based Constitutive Model and Processing Map for T2 Copper During Isothermal and Time-Variant Deformation

Gang Chen,Yu Jin,Jing Wang,Cheng Zhang,Qiang Chen,Hongming Zhang,Xingjian Zhao,Zhiyong Li,Changhai Xie,Zhiming Du 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

Isothermal compression tests were carried out to study the hot deformation behavior of T2 copper under various conditions. The deformation parameters, such as temperature and strain rate, have strong influence on flow stress and microstructureevolution of the alloy. A unified dislocation density-based model considering dynamic recovery and recrystallization wasestablished. And material parameters of the developed model were optimized by genetic algorithm. Comparisons betweenthe experimental and model data demonstrates that the developed model can precisely describe the flow behavior at quitewide range of deformation conditions. Meanwhile, the designed iterative procedure allows the model to be applied in timevariantdeformation conditions. Processing map and microstructure examination were constructed to optimize the processingwindow of the studied alloy. According to the processing maps, flow instability mainly appeared at low temperatures of500–650 °C and strain rates higher than 0.1 s−1. The optimum deformation parameters of T2 copper was concluded as thetemperature range of 700–800 °C and the strain rate of 0.1–1 s−1.

Adaptive Fixed Time Parameter Estimation and Synchronization Control for Multiple Robotic Manipulators

Qiang Chen,Miaomiao Gao,Liang Tao,Yurong Nan 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.9

In this paper, an adaptive fixed time parameter estimation and synchronization control scheme is proposedfor multiple robotic manipulators with unknown parameters and lumped disturbances. A mean coupling synchronization error is defined by averaging all the tracking errors of multiple robotic manipulators, and an adaptive fixed time synchronization control scheme is proposed to guarantee that both the tracking error and the synchronization error can simultaneously converge to zero within a fixed time, which means that the upper bound of the settling time is independent of the initial conditions. Moreover, an adaptive parameter estimation law is developed through constructing auxiliary filtered variables to achieve the accurate estimation of the unknown system parameters. Comparative simulations are provided to validate the effectiveness of the proposed scheme.

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.

Inhibitory Effects of α-Pinene on Hepatoma Carcinoma Cell Proliferation

Chen, Wei-Qiang,Xu, Bin,Mao, Jian-Wen,Wei, Feng-Xiang,Li, Ming,Liu, Tao,Jin, Xiao-Bao,Zhang, Li-Rong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

Background: Pine needle oil from crude extract of pine needles has anti-tumor effects, but the effective component is not known. Methods: In the present study, compounds from a steam distillation extract of pine needles were isolated and characterized. Alpha-pinene was identified as an active anti-proliferative compound on hepatoma carcinoma BEL-7402 cells using the MTT assay. Results: Further experiments showed that ${\alpha}$-pinene inhibited BEL-7402 cells by arresting cell growth in the G2/M phase of the cell cycle, downregulating Cdc25C mRNA and protein expression, and reducing cycle dependence on kinase 1(CDK1) activity. Conclusion: Taken together, these findings indicate that ${\alpha}$-pinene may be useful as a potential anti-tumor drug.

Detection of Methanol in Power Transformer Oil Using Spectroscopy

Qiang Fu,Lei Peng,Li Li,Musong Lin,Yaohong Zhao,Shengli Li,Chen Chen 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.2

Oil-paper insulation in transformers plays an important role in the operation of power grid. At present, the aging (life assessment) of transformers are mainly conducted based upon the degree of polymerization, concentration of furfural, and the gas analysis of CO and CO 2 in the transformer oil. However, these techniques lack sensitive response, especially in the early aging of oil-paper insulation. Methanol as a new indicator to evaluate the aging of insulating paper, is getting more and more attention. An evaluation method based on the measurement of methanol concentration using ultraviolet–visible spectrometer was proposed in this work. After the extraction from transformer oils, the methanol was oxidized using potassium permanganate. Then, chromotropic acid was used to react with the oxidation products (formaldehyde) to form a mauve clathrate, fi nally, the methanol content was measured using the spectroscopy. Diff erent from traditional spectroscopy which calculate only by absorbance at the characteristic wavelength, this paper use the partial least squares method, obtain the relationship between the absorbance at selected regions and the concentration of methanol. The minimum detection limit for the proposed method was 10 ppb, whereas the correlation coeffi cient for the relationship between the absorbance and the concentration of methanol was as high as 0.99.

MULTIPLE SOLUTIONS FOR A CLASS OF QUASILINEAR SCHRÖDINGER SYSTEM IN ℝ^N

Chen, Caisheng,Chen, Qiang Korean Mathematical Society 2016 대한수학회보 Vol.53 No.6

This paper is concerned with the quasilinear $Schr{\ddot{o}}dinger$ system $$(0.1)\;\{-{\Delta}u+a(x)u-{\Delta}(u^2)u=Fu(u,v)+h(x)\;x{\in}{\mathbb{R}}^N,\\-{\Delta}v+b(x)v-{\Delta}(v^2)v=Fv(u,v)+g(x)\;x{\in}{\mathbb{R}}^N,$$ where $N{\geq}3$. The potential functions $a(x),b(x){\in}L^{\infty}({\mathbb{R}}^N)$ are bounded in ${\mathbb{R}}^N$. By using mountain pass theorem and the Ekeland variational principle, we prove that there are at least two solutions to system (0.1).

Protein target identification of ginsenosides in skeletal muscle tissues: discovery of natural small-molecule activators of muscle-type creatine kinase

Chen, Feiyan,Zhu, Kexuan,Chen, Lin,Ouyang, Liufeng,Chen, Cuihua,Gu, Ling,Jiang, Yucui,Wang, Zhongli,Lin, Zixuan,Zhang, Qiang,Shao, Xiao,Dai, Jianguo,Zhao, Yunan The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.3

Background: Ginseng effectively reduces fatigue in both animal models and clinical trials. However, the mechanism of action is not completely understood, and its molecular targets remain largely unknown. Methods: By screening for proteins that interact with the primary components of ginseng (ginsenosides) in an affinity chromatography assay, we have identified muscle-type creatine kinase (CK-MM) as a potential target in skeletal muscle tissues. Results: Biolayer interferometry analysis showed that ginsenoside metabolites, instead of parent ginsenosides, had direct interaction with recombinant human CK-MM. Subsequently, 20(S)-protopanaxadiol (PPD), which is a ginsenoside metabolite and displayed the strongest interaction with CK-MM in the study, was selected as a representative to confirm direct binding and its biological importance. Biolayer interferometry kinetics analysis and isothermal titration calorimetry assay demonstrated that PPD specifically bound to human CK-MM. Moreover, the mutation of key amino acids predicted by molecular docking decreased the affinity between PPD and CK-MM. The direct binding activated CK-MM activity in vitro and in vivo, which increased the levels of tissue phosphocreatine and strengthened the function of the creatine kinase/phosphocreatine system in skeletal muscle, thus buffering cellular ATP, delaying exercise-induced lactate accumulation, and improving exercise performance in mice. Conclusion: Our results suggest a cellular target and an initiating molecular event by which ginseng reduces fatigue. All these findings indicate PPD as a small molecular activator of CK-MM, which can help in further developing better CK-MM activators based on the dammarane-type triterpenoid structure.

Design of Switching System Based on FC-AE-1553 Bus

CHEN Jin-qiang,ZHANG Shan-cong 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.4

As 1553B bus system is also widely used in modern avionics system, so in the new bus system development, not only the quality improvement on the performance is needed, but also should be required to be compatible with the original avionics equipment complying with 1553Bbus protocol , maximum reducing avionics system upgrade difficulty. Based on this consideration, the American National Standards Committee has developed the upper mapping of FC protocol—FC-AE-1553 agreement. FC-AE-155 agreement takes full advantages of the fibre channel and also gives full consideration to the requirement of being compatible with the original 1553B equipment, so the system upgrade can be easily realized. Conduct the fibre bus study based on FC-AE-1553, raise the hardware and software design methods and complete the control system demonstration verification based on fibre-optic bus. At the same time, conduct the bridging technology of FC-AE-1553 and MIL-STD-1553B, construct two types of demonstration verification system for bus bridging, breaking the hardware and software technology of FC-AE-1553 and MIL-STD-1553B bridging and establish the hybrid structure of the high and low speed bus, to meet the needs of the actual model, which plays a very important significance for the further development of China’s aerospace business.

An Exploration of the Coverage of People’s Daily on the “Belt and Road” Initiative-related Issues in Pakistan from a Perspective of Moral Concern and Balance of Interests

Qiang Jin(Qiang Jin),Haibao Yang(Haibao Yang),JinXiao Chen(JinXiao Chen) 아시아사회과학학회 2023 Jornal of Asia Social Science Vol.10 No.1

China-Pakistan relations have been renewed for a long time, especially after the “Belt and Road” initiative and the “China-Pakistan Economic Corridor” were put forward, the cooperation between the two countries has continued to deepen and become more solid. “People's Daily” is best at grasping the situation at home and abroad, and it can also reflect the will of the country, constantly weighing between “morality” and “interest”. Its reports on Pakistan are representative among domestic media. Reports show an irregular trend, with fluctuations and declines. There are various types of reports, but they are mainly news, with the layout at the front. The length is relatively long, and the sources of news are more authoritative. In terms of content, the main body of the report is clear, and the leader’s news accounts for a large proportion. China-Pakistan economic cooperation and the China-Pakistan Economic Corridor are the main ones, and positive reports are mainly used. There are more neutral and negative reports in social news. In the cultural field, education exchanges and Youth exchanges are the main focus, and the military field is mainly military cooperation and counter-terrorism. Relevant reporting can also increase the amount of in-depth reporting, provide diversity information, and focus more on cultural reporting.

Characterization of proteolysis in muscle tissues of sea cucumber Stichopus japonicus

Chen-Chen Zhao,Yang Yang,Hai-tao Wu,Zhi-Mo Zhu,Yue Tang,Cui-Ping Yu,Na Sun,Qiang Lv,Jia-Run Han,Ao-Ting Li,Jia-Nan Yan,Yue Cha 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.6

The proteolysis in muscle tissues of sea cucumber Stichopus japonicus (sjMTs) was characterized. The proteins from sjMTs were primarily myosin heavy chains (MHCs), paramyosin (Pm), and actin (Ac) having a molecular mass of approximately 200, 98, and 42 kDa, respectively. Based on SDS-PAGE analysis and quantification of trichloroacetic acid (TCA)-soluble peptides released, degradation of muscle proteins from sjMTs was favorable at pH 5 and 50°C. Proteolysis of MHCs was mostly inhibited by cysteine protease inhibitors, including trans-epoxysuccinyl-L-leucyl-amido (4- guanidino) butane (E-64) and antipain (AP). E-64 and AP completely inhibited the degradation of Pm and Ac, while iodoacetic acid showed a partially inhibitory effect. These results indicated that the proteolysis of sjMTs was mainly attributed to cysteine proteases. Avoidance of setting the tissues at 40–50oC and slightly acidic condition and inhibition of cysteine proteases are helpful for decreasing sea cucumber autolysis.