Research on Braking Process of High-speed Train with Aerodynamic Brake

Yonghua Zhu,Weilie Shang,Xia Zhang,Hongjie Yan,Pin Wu 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12

The speed is higher, the kinetic energy is greater. In order to ensure the safety of a new generation train running in a high speed, it is necessary to research on its braking performance. In this paper, the braking force, running resistance, braking time, braking distance and the deceleration generated by the train with two kinds of braking wings were analyzed while the high-speed train was doing deceleration movement. And the results were compared and analyzed between the train with and without braking wing, and between the two kinds of braking wings. The results showed that the high speed train with braking wings made much contribution to the acceleration in the braking process, especially the train is in high speed.

Phospholipid and Fatty Acid Composition in Leaves and Roots of Ten Autumn Chrysanthemum Cultivars Grown at Low Temperature

Yan Li,Yonghua Li,Pan Yang,Hua’ao Zhang,Dan He 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.4

The objective of this study was to evaluate the relationship between cold hardiness and phospholipid andfatty acid content in leaves and roots of chrysanthemum, and to explore cold resistance mechanisms of chrysanthemumin order to provide a theoretical basis for selecting and breeding a new cold-resistant cultivar. We analyzed thephospholipid and fatty acid components in leaves and roots of 10 autumn chrysanthemum cultivars including sixearly-flowering cultivars and four late-flowering cultivars. We determined the content of phosphatidyl ethanolamine(PE), phosphatidyl choline (PC), phosphatidyl serine (PS), phosphatidyl glycerol (PG), myristic acid (C14:0), palmiticacid (C16:0), stearic acid (C18:0), docosanoic acid (C22:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid(C18:3) in leaves and roots of chrysanthemum seedlings grown at 16C and 5C. The cultivars had different responsesto low temperature that included changes in the cell membrane composition in leaves and roots. The main phospholipidin leaves and roots of chrysanthemum was PE, and the main saturated fatty acid was palmitic acid. Amongunsaturated fatty acids, linolenic acid was found in leaves, whereas oleic acid and linoleic acid were present in theroots. Based on the unsaturated fatty acid content and the ratio of unsaturated to saturated fatty acids in leaves, theearly-flowering cultivars ‘Tan Xiang Shi Zi’ and ‘Tong Que Chun Shen’ and the late-flowering cultivars ‘Guan DongXin Xia’ and ‘Yun Long Feng Wu’ were classified as strongly cold tolerant, while the early-flowering cultivar ‘JinFeng Ling’ and the late-flowering cultivar ‘Mo Bao’ were weakly cold tolerant.

Tunable green-yellow-red light properties of NaY(WO4 )2:Mn2+, Dy3+, Eu3+ phosphors excited with 365 nm LED

Yonghua Wu,Fugui Yang,Hao Zhang,Fengpo Yan,Ruijuan Zuo 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.4

By the solid-state reaction method, the NaY(WO4)2 : Mn2+, Dy3+, Eu3+ phosphors are synthesized successfully. The sample’sphase-structure and morphology have been characterized by XRD and EDS. The concentrations of Mn2+, Dy3+, Eu3+, Y3+ andW6+ are measured by ICP, The result implies that the doped process of Mn2+, Dy3+ and Eu3+ is very easy in host NaY(WO4)2. The absorption and excited spectra are presented, The absorption spectrum of Mn2+ is always broad, but the Dy3+, Eu3+hasrelatively sharp absorption peaks.Using the commercial LED of 365 nm wavelength as the excitation light, the emission spectrawith different doped concentrations ratios of Mn2+ are obtained. The Mn2 + doping reduces the emission intensity of Dy3+,alsoit has meaningful influence on the tunable green-yellow-red LED.The high doped concentration of Mn2+ can guarantee theemission intensity of 546 nm enough.

Research on Feature Extraction based on Deep Learning

Wu Pin,Yan Hongjie,Shang Weilie,Zhu Yonghua,Gao Honghao 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.11

With the development of deep learning, it has achieved impressive results in feature extraction field. This paper drives research in feature extraction based on deep learning. First, this paper gives a brief introduction on the world's research status on deep learning and principle of Restricted Boltzmann machine (RBM). Then this paper conducts reducing experiment based on RBM for handwritten digits. According to the analysis based on the results of the experiments, this paper tries to get a proper dimension which handwritten digits reduced to achieve better performance. Finally, this paper finds that it reach the goal when handwritten digits is reduced to half dimensional raw digits. This is an important foundation of deep learning layering and offers help to researchers in feature extraction based on deep learning.

LES investigation into the generation of momentum deficits in the supersonic wake of a micro-ramp

Xiao Wang,Yonghua Yan,Zhengzhong Sun,Chaoqun Liu 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.4

Implicitly implemented large eddy simulation (LES) with a fifth-order WENO scheme was conducted in this study. Based on Navier- Stokes equations, this LES was carried out to explore the origin of momentum deficit caused by a supersonic micro-ramp at flow conditions of Ma = 2.5 and Reθ = 5760. The numerical results were validated through qualitative and quantitative comparisons with existing experimental data. After describing the aerodynamic properties of the supersonic wake, such as the deficit and the streamwise vortices, the momentum deficit was later detected to originate from the lower portion of the upstream boundary layer, while the high momentum fluid originated from close to the wall at the upper portion. Position alternation trigged by the micro-ramp was finally proposed as a revised mechanism.

Panaxadiol saponins treatment caused the subtle variations in the global transcriptional state of Asiatic corn borer, Ostrinia furnacalis

Shuangli Liu,Yonghua Xu,Yugang Gao,Yan Zhao,Aihua Zhang,Liansheng Zang,Chunsheng Wu,Lianxue Zhang 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.1

Background: The lepidopteran Asiatic corn borer (ACB), Ostrinia furnacalis (Guenee), has caused hugeeconomic losses throughout the Asian-Western Pacific region. Usually, chemical pesticides are used forthe control, but excessive use of pesticides has caused great harm. Therefore, the inartificial ecotypicpesticides to ACB are extremely essential. In our previous study, we found that panaxadiol saponins(PDS) can effectively reduce the harm of ACB by causing antifeedant activity. Therefore, it is necessary toreveal the biological molecular changes in ACB and the functionary mechanism of PDS. Methods: We analyzed the global transcription of ACB with different PDS concentration treatment (5 mg/mL, 10 mg/mL, and 25 mg/mL) by high-throughput sequencing and de novo transcriptome assemblymethod. Results: PDS treatment could cause the changes of many gene expressions which regulate its signalpathways. The genes in peroxisome proliferatoreactivated receptor (PPAR) signaling pathway weresignificantly downregulated, and then, the downstream fatty acid degradation pathway had also beengreatly affected. Conclusion: Through this experiment, we hypothesized that the occurrence of antifeedant action of ACBis because the PDS brought about the downregulation of FATP and FABP, the key regulators in the PPAR,and the downregulation of FATP and FABP exerts further effects on the expression of SCD-1, ACBP, LPL,SCP-X, and ACO, which leads to the disorder of PPAR signaling pathway and the fatty acid degradationpathway. Not only that, PDS treatment leads to enzyme activity decrease by inhibiting the expression ofgenes associated with catalytic activity, such as cytochrome P450 and other similar genes.

Lattice Boltzmann simulation of the spreading behavior of a droplet impacting on inclined solid wall

Wanyu Chen,Fan Yang,Yonghua Yan,Xueyan Guo,Ren Dai,Xiaoshu Cai 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.6

The spreading behavior of a 3D droplet impacting on inclined solid wall is presented by using a lattice Boltzmann method (LBM) with single component multiphase pseudopotential model. The time evolution of spreading factor, dimensionless spreading width, dimensionless height, dimensionless bottom area and adhesion force are obtained. Our numerical results show that when increasing the contact angle or inclination angle, the dimensionless height and the dimensionless bottom area increases but the dimensionless spreading length and spreading width decreases. In addition, the progresses of circumferential spreading in starting-up and spreading stages and the aggregation at front edge in retracting stage would be more obvious by decreasing the viscosity or increasing the Bond number.

Simulation of natural convection in an inclined polar cavity using a finite-difference lattice Boltzmann method

Fan Yang,Haicheng Yang,Yonghua Yan,Xueyan Guo,Ren Dai,Chaoqun Liu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.6

Natural convection heat transfer in an inclined polar cavity was studied using a Finite-difference lattice Boltzmann method (FDLBM)based on a double-population approach for body-fitted coordinates. A D2G9 model coupled with the simplest TD2Q4 lattice model wasapplied to determine the velocity field and temperature field. For both velocity and temperature fields, the discrete spatial derivativeswere obtained by combining the upwind scheme with the central scheme, and the discrete temporal term is obtained using a fourth-orderRunge-Kutta scheme. Studies were carried out for different Rayleigh numbers and different inclination angles. The results in terms ofstreamlines, isotherms, and Nusselt numbers explain the heat transfer mechanism of natural convection in an inclined polar cavity due tothe change of Rayleigh number and inclination angle.

Panaxadiol saponins treatment caused the subtle variations in the global transcriptional state of Asiatic corn borer, Ostrinia furnacalis

Liu, Shuangli,Xu, Yonghua,Gao, Yugang,Zhao, Yan,Zhang, Aihua,Zang, Liansheng,Wu, Chunsheng,Zhang, Lianxue The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.1

Background: The lepidopteran Asiatic corn borer (ACB), Ostrinia furnacalis (Guenee), has caused huge economic losses throughout the Asian-Western Pacific region. Usually, chemical pesticides are used for the control, but excessive use of pesticides has caused great harm. Therefore, the inartificial ecotypic pesticides to ACB are extremely essential. In our previous study, we found that panaxadiol saponins (PDS) can effectively reduce the harm of ACB by causing antifeedant activity. Therefore, it is necessary to reveal the biological molecular changes in ACB and the functionary mechanism of PDS. Methods: We analyzed the global transcription of ACB with different PDS concentration treatment (5 mg/mL, 10 mg/mL, and 25 mg/mL) by high-throughput sequencing and de novo transcriptome assembly method. Results: PDS treatment could cause the changes of many gene expressions which regulate its signal pathways. The genes in peroxisome proliferator-activated receptor (PPAR) signaling pathway were significantly downregulated, and then, the downstream fatty acid degradation pathway had also been greatly affected. Conclusion: Through this experiment, we hypothesized that the occurrence of antifeedant action of ACB is because the PDS brought about the downregulation of FATP and FABP, the key regulators in the PPAR, and the downregulation of FATP and FABP exerts further effects on the expression of SCD-1, ACBP, LPL, SCP-X, and ACO, which leads to the disorder of PPAR signaling pathway and the fatty acid degradation pathway. Not only that, PDS treatment leads to enzyme activity decrease by inhibiting the expression of genes associated with catalytic activity, such as cytochrome P450 and other similar genes.