FORMATION AND QUASI-PERIODIC BEHAVIOR OF OUTER SPIRAL RAINBANDS IN A NUMERICALLY SIMULATED TROPICAL CYCLONE

Qingqing LI,Yuqing WANG 한국기상학회 2011 한국기상학회 학술대회 논문집 Vol.2011 No.10-2

Optimal Design of Multi-DOF Deflection Type PM Motor by Response Surface Methodology

Li, Zheng,Zhang, Lu,Lun, Qingqing,Jin, Hongbo The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

This paper uses response surface methodology as the optimization method of torque of multi-DOF deflection type PM motor. Firstly, the application of Taguchi algorithm selects structural parameters affecting the motor torque largely which simplifies the optimization process greatly. Then, based on the central composite design (CCD), response surface equation numerical model is constructed by the finite element method. With the aid of experiment design and analysis software, the effects of the interaction among factors on the index are analyzed. The results show that the analytical method is efficient and reliable and the experimental results can be predicted by response surface functions.

Study on hydrodynamic performance of Heavier-than-water AUV with overlapping grid method

Li, Xiang,Zhao, Min,Zhao, Faming,Yuan, Qingqing,Ge, Tong Techno-Press 2014 Ocean systems engineering Vol.4 No.1

Hydrodynamic coefficients strongly affect the dynamic performance of autonomous underwater vehicles (AUVs). A novel kind of underwater vehicle (Heavier-than-water AUV) with higher density than water is presented, which is different from conventional ones. RANS method and overlapping grids are used to simulate the flow field around the vehicle. Lifts, drags and moments of different attack and drift angles in steady state are calculated. The hydrodynamic performances and how the forces change with the attitude are analyzed according to the flow field structure. The steady-state results using overlapping grid method are compared with those of software FLUENT and wind tunnel tests. The calculation results show that the overlapping grid method can well simulate the viscous flow field around the underwater vehicle. Overlapping grid skills have also been used to figure out the planar-motion-mechanism (PMM) problem of Heavier-than-water AUV and forecast its hydrodynamic performance, verifying its effectiveness in dealing with the dynamic problems, which would be quite helpful for design and control of Heavier-than-water AUV and other underwater vehicles.

A Simplifed Common‑Mode Voltage Suppression and Neutral‑Point Potential Control for the NPC Three‑Level Inverter

Qingqing Yuan,Jinyue Qian,An Li 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

Neutral-point potential unbalancing is an inherent disadvantage of NPC three-level inverter. Traditional control methods, e.g. the space vector PWM (SVPWM) considering balance factor or the model predictive control (MPC), usually needs large amounts of calculation and the common-mode voltage usually keeps large due to the zero vectors being involved in the modulation or the roll optimization. Aiming at above problems, this paper proposes a simplifed model predictive algorithm based on the characteristics analysis on the unbalancing and common-mode voltage. Firstly, an approximate twolevel structure containing 12 vectors is proposed by the reduced-order processing for the three-level structure, which solves the calculation complexity problem. Meanwhile, multi-constraints including switching frequency, neutral-point potential deviation and the common-mode voltage, are constructed within the roll optimization items of the MPC scheme to make common-mode voltage being restricted less than 1/6 DC voltage while the switching frequency is almost constant. Finally, experiments were carried out to verify that this method can realize a neutral-point voltage balance and a low common-mode voltage along with less execution time.

Optimal Design of Multi-DOF Deflection Type PM Motor by Response Surface Methodology

Zheng Li,Lu Zhang,Qingqing Lun,Hongbo Jin 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

This paper uses response surface methodology as the optimization method of torque of multi-DOF deflection type PM motor. Firstly, the application of Taguchi algorithm selects structural parameters affecting the motor torque largely which simplifies the optimization process greatly. Then, based on the central composite design (CCD), response surface equation numerical model is constructed by the finite element method. With the aid of experiment design and analysis software, the effects of the interaction among factors on the index are analyzed. The results show that the analytical method is efficient and reliable and the experimental results can be predicted by response surface functions.

Extratropical Transition Times of Mindulle (2004) and Yagi (2006)

Qian WANG,Qingqing LI,Gang FU 한국기상학회 2011 한국기상학회 학술대회 논문집 Vol.2011 No.10-2

Vagal Transient Receptor Potential Ankyrin 1 Mediates Stress-exacerbated Visceral Mechanonociception After Antral Cold Exposure

Xin Chen,Qingqing Luo,Xiujuan Yan,Wenting Li,Shengliang Chen 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.3

Background/AimsAbdominal pain can be evoked or exacerbated after gastrointestinal cold stimulation in some patients with diarrhea-predominantirritable bowel syndrome (IBS-D), indicating a low temperature-induced sensitization of visceral perception. We investigated the roleof vagal transient receptor potential ankyrin 1 (TRPA1, a cold-sensing ion channel) in cold-aggravated visceral mechanonociception ina stress-induced IBS animal model. MethodsTRPA1 expression was examined in antral biopsies of healthy controls and IBS-D patients. Abdominal symptoms were assessed beforeand after warm or cold water intake. The visceromotor response (VMR) to colorectal distention (CRD) following intra-antral infusionof cold saline was measured in animals undergoing sham or chronic water avoidance stress. TRPA1 expression, extracellular signalregulatedprotein kinase 1/2 (ERK1/2) phosphorylation, and neuronal calcium influx in vagal afferents were assessed. ResultsCompared to healthy controls, IBS-D patients displayed elevated antral TRPA1 expression, which was associated with symptom scoresafter cold (4°C) water intake. Intra-antral infusion of cold saline increased VMR to CRD in naive rats, an effect dependent on vagalafferents. In stressed rats, this effect was greatly enhanced. Functional blockade and gene deletion of TRPA1 abolished the cold effecton visceral nociception. TRPA1 expression in vagal (but not spinal) afferents increased after stress. Moreover, the cold-induced, TRPA1-dependent ERK1/2 activation and calcium influx in nodose neurons were more robust in stressed rats. ConclusionsStress-exaggerated visceral mechanonociception after antral cold exposure may involve up-regulation of TRPA1 expression andfunction on vagal afferents. Our findings reveal a novel mechanism for abnormal gastrointestinal cold sensing in IBS.

Colorimetric H2O2 Detection Using Ag-Nanoparticle-Decorated Silica Microspheres

Zhikun Zhang,Qingqing Liu,Yumin Liu,Ran Qi,Lilong Zhou,Zhengjie Li,Jimmy Yun,Runjing Liu,Yongqi Hu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.02

In view of the importance of convenient and rapid H2O2 detection for biological analysis, we herein propose Ag nanoparticle (NP)-decorated silica microspheres as a probe for instant and non-enzymatic on-site colorimetric detection of H2O2. The surface hydroxyl groups of silica microspheres were reacted with (3-mercaptopropyl)trimethoxysilane to afford thiolated microspheres that subsequently bind Ag NPs. The oxidation of residual –SH groups on the silica surface to –S–S– moieties in the presence of H2O2 induces the aggregation of decorated microspheres and is accompanied by a color change. Sensor response is found to be proportional to H2O2 concentration in the range from 100 nM to 1 mM, with UV–Vis and colorimetric detection limits determined as 10 -8 M and 10 -5 M, respectively. The developed platform is successfully used to detect H2O2 in simulated human urine and is, therefore, concluded to be sufficiently stable and selective for practical applications.

Elevated Expression of RIOK1 Is Correlated with Breast Cancer Hormone Receptor Status and Promotes Cancer Progression

Zhiqi Huang,Xingyu Li,Tian Xie,Changjiang Gu,Kan Ni,Qingqing Yin,Xiaolei Cao,Chunhui Zhang 대한암학회 2020 Cancer Research and Treatment Vol.52 No.4

Purpose RIOK1 has been proved to play an important role in cancer cell proliferation and migration in various types of cancers—such as colorectal and gastric cancers. However, the expression of RIOK1 in breast cancer (BC) and the relationship between RIOK1 expression and the development of BC are not well characterized. In this study, we assessed the expression of RIOK1 in BC and evaluated the mechanisms underlying its biological function in this disease context. Materials and Methods We used immunohistochemistry, western blot and quantitative real-time polymerase chain reaction to evaluate the expression of RIOK1 in BC patients. Then, knockdown or overexpression of RIOK1 were used to evaluate the effect on BC cells in vitro and in vivo. Finally, we predicted miR-204-5p could be a potential regulator of RIOK1. Results We found that the expression levels of RIOK1 were significantly higher in hormone receptor (HR)–negative BC patients and was associated with tumor grades (p=0.010) and p53 expression (p=0.008) and survival duration (p=0.011). Kaplan-Meier analysis suggested a tendency for the poor prognosis. In vitro, knockdown of RIOK1 could inhibit proliferation, invasion, and induced apoptosis in HR-negative BC cells and inhibited tumorigenesis in vivo, while overexpression of RIOK1 promoted HR-positive tumor progression. MiR-204-5p could regulate RIOK1 expression and be involved in BC progression. Conclusion These findings indicate that RIOK1 expression could be a biomarker of HR-negative BC, and it may serve as an effective prognostic indicator and promote BC progression.

Graphene Oxide/Polyester Fabric Composite by Electrostatic Self-Assembly as a New Recyclable Adsorbent for the Removal of Methylene Blue

Di Wang,Dawei Li,Pengfei Lv,Qingqing Wang,Yang Xu,Qufu Wei 한국섬유공학회 2018 Fibers and polymers Vol.19 No.8

A novel graphene oxide/polyester (GO/PET) composite fabric as a recyclable adsorbent was prepared via electrostatic self-assembly. The structure, morphology, and properties of the GO/PET composite fabrics were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and contact angle (CA), respectively. The absorption property was evaluated by the absorption amount and removal efficiency of methylene blue (MB) solution on the GO/PET composite fabric. The results indicated that the absorption amount was found to be 21.80 mg/g and the removal efficiency reached 99.93 % under the experimental conditions of GO concentration of 2 mg/ml, initial concentration of 50 mg/l, and area of 64 cm2. The experimental parameters were investigated including the concentration of GO, the initial concentration of MB solutions, and adsorbent area. Simultaneously, according to a series of dynamic analysis, the absorption process revealed that the kinetics was well-described by pseudo-second-order model. This study showed that the GO/PET composite fabric could be a recyclable, efficient adsorbent material for the environmental cleanup.