Numerical Investigation on Effects of Rivulet and Cable Oscillation of a Stayed Cable in Rain-wind-induced Vibration

Peng Xie,Chao Ying Zhou 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.3

Rain-wind-induced vibration (RWIV) appeared on cable stayed bridges involves complicated fluid and structure interactions and its mechanism is not fully understood. It is believed that the upper-rivulet which is often seen when the RWIV occurs plays an important role. In this paper, a numerical investigation on the effects of the upper rivulet on the aerodynamic forces of the cable and the interaction between the fluid flow and the cable oscillation is carried out where the cable with the upper-rivulet is modeled by a circular cylinder with an arch attachment. The Reynolds number of 6.8×104 is selected. The large-eddy simulation (LES) method with Smagorinsky-Lilly modeling is employed to simulate the 3-D turbulent flow field, and a moving mesh method is introduced to deal with the oscillation of the cylinder. The aerodynamic forces on the cylinder and the flow patterns around the cylinder are analyzed for both steady and oscillation status of the cylinder with the rivulet attachment in different position angle ranged from 0˚ to 60˚. The results show that the aerodynamic forces on the cylinder change largely with the position angle of the rivulet attachment. In the steady cases, a uniform recirculation flow along the axial direction of the cylinder forms behind the cylinder; whereas in the oscillation cases, a 3-D periodical recirculation flow appears along the axial direction. The scales of these recirculation zones are influenced by both the position angle of the rivulet and the dynamic status of the cylinder. The results also show that there exists a rivulet position angle where the aerodynamic force on the cable and flow pattern around the cable both change dramatically. This critical position angle is found to be 45˚ for the cases studied.

Realgar transforming solution suppresses angiogenesis and tumor growth by inhibiting VEGF receptor 2 signaling in vein endothelial cells

Peng Song,Yang Hai,Xin Wang,Longhe Zhao,Baoqiang Chen,Peng Cui,Qin-Jian Xie,Lan Yu,Yang Li,Zhengrong Wu,Hong Yu Li 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.4

Realgar (As4S4), as an arsenic sulfide mineraldrug, has a good therapeutic reputation for anticancer inTraditional Chinese Medicine, and has recently beenreported to inhibit angiogenesis in tumor growth. However,considering the poor solubility and low bioavailability ofrealgar, large dose of realgar and long period of treatmentare necessary for achieving the effective blood medicineconcentration. In present study, we resolved the crucialproblem of poor solubility of realgar by using intrinsicbiotransformation in microorganism, and investigatedunderlying mechanisms of realgar transforming solution(RTS) for antiangiogenesis. Our results demonstrated thatRTS had a strong activity to inhibit HUVECs proliferation,migration, invasion, and tube formation. Moreover, RTSinhibited VEGF/bFGF-induced phosphorylation ofVEGFR2 and the downstream protein kinases includingERK, FAK, and Src. In vivo zebrafish and chickenchorioallantoic membrane model experiments showed thatRTS remarkably blocked angiogenesis. Finally, comparedwith the control, administration of 2.50 mg/kg RTSreached more than 50% inhibition against H22 tumorallografts in KM mice, but caused few toxic effects in thehost. The antiangiogenic effect was indicated by CD31immunohistochemical staining and alginate-encapsulatedtumor cell assay. In summary, our findings suggest thatRTS inhibits angiogenesis and may be a potential drugcandidate in anticancer therapy.

Robust Fault Estimation Design for Discrete-Time Nonlinear Systems via A Modified Fuzzy Fault Estimation Observer

Xie, Xiang-Peng,Yue, Dong,Park, Ju H. Elsevier 2018 ISA transactions Vol.73 No.-

<P><B>Abstract</B></P> <P>The paper provides relaxed designs of fault estimation observer for nonlinear dynamical plants in the Takagi–Sugeno form. Compared with previous theoretical achievements, a modified version of fuzzy fault estimation observer is implemented with the aid of the so-called maximum-priority-based switching law. Given each activated switching status, the appropriate group of designed matrices can be provided so as to explore certain key properties of the considered plants by means of introducing a set of matrix-valued variables. Owing to the reason that more abundant information of the considered plants can be updated in due course and effectively exploited for each time instant, the conservatism of the obtained result is less than previous theoretical achievements and thus the main defect of those existing methods can be overcome to some extent in practice. Finally, comparative simulation studies on the classical nonlinear truck-trailer model are given to certify the benefits of the theoretic achievement which is obtained in our study.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A modified fuzzy fault estimation observer is developed by the aid of a maximum-priority-based switching law. </LI> <LI> The criterion takes the form of an LMI which is computationally tractable. </LI> <LI> The obtained observer design conditions are less conservative. </LI> </UL> </P>

Heat kernel estimates for Dirichlet fractional Laplacian with gradient perturbation

Peng Chen,Renming Song,Longjie Xie,Yingchao Xie 대한수학회 2019 대한수학회지 Vol.56 No.1

We give a direct proof of the sharp two-sided estimates, recently established in \cite{C-K-S-1, P-R}, for the Dirichlet heat kernel of the fractional Laplacian with gradient perturbation in $C^{1, 1}$ open sets by using Duhamel's formula. We also obtain a gradient estimate for the Dirichlet heat kernel. Our assumption on the open set is slightly weaker in that we only require $D$ to be $C^{1,\theta}$ for some $\theta\in (\alpha/2, 1]$.

HEAT KERNEL ESTIMATES FOR DIRICHLET FRACTIONAL LAPLACIAN WITH GRADIENT PERTURBATION

Chen, Peng,Song, Renming,Xie, Longjie,Xie, Yingchao Korean Mathematical Society 2019 대한수학회지 Vol.56 No.1

We give a direct proof of the sharp two-sided estimates, recently established in [4, 9], for the Dirichlet heat kernel of the fractional Laplacian with gradient perturbation in $C^{1,1}$ open sets by using Duhamel's formula. We also obtain a gradient estimate for the Dirichlet heat kernel. Our assumption on the open set is slightly weaker in that we only require D to be $C^{1,{\theta}}$ for some ${\theta}{\in}({\alpha}/2,1]$.

Dexmedetomidine promotes the progression of hepatocellular carcinoma through hepatic stellate cell activation

Chen Peng,Luo Xiaojun,Dai Guanqi,Jiang Yuchuan,Luo Yue,Peng Shuang,Wang Hao,Xie Penghui,Qu Chen,Lin Wenyu,Hong Jian,Ning Xue,Li Aimin 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Dexmedetomidine (DEX) is an anesthetic that is widely used in the clinic, and it has been reported to exhibit paradoxical effects in the progression of multiple solid tumors. In this study, we sought to explore the mechanism by which DEX regulates hepatocellular carcinoma (HCC) progression underlying liver fibrosis. We determined the effects of DEX on tumor progression in an orthotopic HCC mouse model of fibrotic liver. A coculture system and a subcutaneous xenograft model involving coimplantation of mouse hepatoma cells (H22) and primary activated hepatic stellate cells (aHSCs) were used to study the effects of DEX on HCC progression. We found that in the preclinical mouse model of liver fibrosis, DEX treatment significantly shortened median survival time and promoted tumor growth, intrahepatic metastasis and pulmonary metastasis. The DEX receptor (ADRA2A) was mainly expressed in aHSCs but was barely detected in HCC cells. DEX dramatically reinforced HCC malignant behaviors in the presence of aHSCs in both the coculture system and the coimplantation mouse model, but DEX alone exerted no significant effects on the malignancy of HCC. Mechanistically, DEX induced IL-6 secretion from aHSCs and promoted HCC progression via STAT3 activation. Our findings provide evidence that the clinical application of DEX may cause undesirable side effects in HCC patients with liver fibrosis.

Injection molding of ultra-fine zirconia (Y-TZP) powders

Zhi-peng Xie,Zhong-zhou Yi,Bing Xiaoc, Yan Gao,Jie-sheng Luo,Jian-bao Li,Yong Huang 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.1

Injection moldings of three types of ultra-fine zirconia powder were investigated. It was demonstrated that powder characteristics involving particle size, particle size distribution, particle shape and specific surface area significantly affect the optimal compositions of binders and ceramic powders, and the properties of sintered compacts. Investigation of the injection molding variables showed that an excessive barrel-deposited value may easily lead to defects in the debound and sintered bodies. It was also demonstrated that the microstructure of a sintered body can be affected by heating rates influencing grain growth, and that suitable heating rates to the high temperature sintering stage for the three powders are different.

Research on Three Dimensional Reconstruction of Plant Root Based on spatial Geometry Structure and Morphology Architecture Parameters

Wu Peng,Wang Bao-kun,Leng Xin,Xie Peng-cheng 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.6

The root plays an important role in the ecosystem of plants. In order to solve the problem that to measure the root is difficult, this article proposes the three dimensional morphology model of plant root based on spatial geometry structure and morphology architecture parameters, and realize the three dimensional visualization of root. First, constructing three dimensional display model including root axis growing model, branch geometry model and root axis curve model; then combining topological structure of root, we confirm corresponding pixel, using morphology characteristic parameters outputted by root morphology to conduct the three dimensional reconstruction of root. Finally, we realize the visualization expression of plant root, basing on the VTK simulation software. The result of simulation, for establishing the whole visualization plant growing root further, lays technical foundation.

Deep Learning-Based Modulation Detection for NOMA Systems

( Wenwu Xie ),( Jian Xiao ),( Jinxia Yang ),( Ji Wang ),( Xin Peng ),( Chao Yu ),( Peng Zhu ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.2

Since the signal with strong power need be demodulated first for successive interference cancellation (SIC) receiver in non-orthogonal multiple access (NOMA) systems, the base station (BS) need inform the near user terminal (UT), which has allocated higher power, of the far UT’s modulation mode. To avoid unnecessary signaling overhead of control channel, a blind detection algorithm of NOMA signal modulation mode is designed in this paper. Taking the joint constellation density diagrams of NOMA signal as the detection features, the deep residual network is built for classification, so as to detect the modulation mode of NOMA signal. In view of the fact that the joint constellation diagrams are easily polluted by high intensity noise and lose their real distribution pattern, the wavelet denoising method is adopted to improve the quality of constellations. The simulation results represent that the proposed algorithm can achieve satisfactory detection accuracy in NOMA systems. In addition, the factors affecting the recognition performance are also verified and analyzed.

Mechanism underlying 2n male and female gamete formation in lemon via cytological and molecular marker analysis

Kai‑Dong Xie,Qiang‑Ming Xia,Jun Peng,Xiao‑Meng Wu,Zong‑Zhou Xie,Chun‑Li Chen,Wen‑Wu Guo 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.2

The unreduced (2n) gametes have long been used in triploid breeding of citrus. In lemon, the previously reported mechanisms for 2n megagametophyte formation were controversial, whereas that for 2n pollen production is still unknown. Herein, the frequency of and mechanism underlying 2n megagametophyte and 2n pollen formation in ‘Eureka’ lemon were investigated based on cytological observation and genotyping of the triploid hybrids between ‘Eureka’ lemon and ‘Early gold’ sweet orange. As a result, 4.79% of the viable pollens of ‘Eureka’ lemon were identified as the 2n pollen with a larger diameter (70.16 ± 3.92 μm). The 2n pollen might be resulted from the formation of parallel spindles at meiosis stage II. Among the 204 plantlets regenerated from embryo rescue following the sexual cross, 12 were triploids as identified by flow cytometry. According to the analysis of heterozygosity transmission using 13 pericentromeric single nucleotide polymorphism (SNP) markers and 20 randomly distributed simple sequence repeat (SSR) markers, 11 triploids were identified to be originated from the fertilization of 2n megagametophytes of ‘Eureka’ lemon, with a frequency of 5.39%. Among them, nine 2n megagametophytes were supposed to be arisen from the second division restitution (SDR), whereas the other two were from postmeiotic genome doubling (PMD). These results to understand the mechanism underlying 2n gamete formation in lemon are valuable for its efficient polyploid breeding.