3D Analytical Model of Permanent Magnet and Electromagnetic Hybrid Halbach Array Electrodynamic Suspension System

Cheng Luo,Kunlun Zhang,Wenlong Zhang,Yongzhi Jing 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

In this paper, a 3D analytical model of permanent magnet (PM) and electromagnetic hybrid Halbach array electrodynamic suspension (EDS) system for a conductive plate is presented. When the hybrid Halbach array moves to cut the conductive plate, the 3D eddy current forces are derived using the second-order vector potential (SOVP) based on y-component of the source magnetic fux density, which is derived using the Biot–Savart law and surface current method. The accuracy of the derived equations is verifed by a 3D fnite-element analysis (FEA) model. Furthermore, the efects of the main characteristic parameters on the levitation force are analysed.

Wavelength switchable flat-top all-fiber comb filter based on a double-loop Mach-Zehnder interferometer

Luo, Ai-Ping,Luo, Zhi-Chao,Xu, Wen-Cheng,Cui, Hu The Optical Society 2010 Optics express Vol.18 No.6

<P>A wavelength switchable all-fiber comb filter with flat-top spectral response based on a double-loop Mach-Zehnder (M-Z) interferometer is proposed and demonstrated. The proposed flat-top filter consists of a rotatable polarizer and a double-loop M-Z interferometer composed of two fiber couplers with a polarization controller (PC) in the first loop. In the theoretical analysis, when the second coupler of the M-Z interferometer is a non-3dB one, with proper settings of the polarization state of the input light and the PC, the wavelength switchable comb filter with flat-top passband can be obtained. Theoretical prediction was verified by experimental demonstration. The measured 1 dB bandwidth was 0.51 nm with a channel spacing of 0.98 nm, indicating that the flat-top passband of 1 dB bandwidth extends to about 50% of the comb spacing.</P>

INDEFINITE STOCHASTIC OPTIMAL LQR CONTROL WITH CROSS TERM UNDER IQ CONSTRAINTS

Luo, Cheng-Xin,Feng, En-Min 한국전산응용수학회 2004 Journal of applied mathematics & informatics Vol.15 No.1

A stochastic optimal LQR control problem under some integral quadratic (IQ) constraints is studied, with cross terms in both the cost and the constraint functionals, allowing all the control weighting matrices being indefinite. Sufficient conditions for the well-posedness of this problem are given. When these conditions are satisfied, the optimal control is explicitly derived via dual theory.

Rapid On-Site Improvement of Over-Wet Fluvioglacial Deposits Filler for Highway Subgrade Construction

Cheng Luo,Mingjing Fang,Shicong Zhai,Xiangping Ou,Yang Pu 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.11

The compaction of over-wet fluvioglacial deposits filler is difficult due to its high moisture content. This paper presents an easy but effective improvement method to treat over-wet fluvioglacial deposits using quicklime. Firstly, several tests are conducted to figure out the properties of the over-wet fluvioglacial deposits. Then, the relationship curves between the difference of natural-optimal moisture content and compaction degree are established. Finally, field test is carried out and the compaction degree of the subgrade soil is evaluated by sand cone method. The field test in the case study shows that the moisture content difference of filler is 10.9%, and the optimal quicklime content is 6% according to the curves. Results indicate that the average compaction degree of subgrade soil is 94.90% (>93%) and the value of CBR is much higher than required 3%, which proves that the method using quicklime works well to improve over-wet fluvioglacial deposits filler for rapid construction of highway embankment. Considering the inadequacy of stiffness of quicklime-treated filler, the rapid increase of stiffness for the upper roadbed using over-wet fluvioglacial deposits filler needs further research.

Study of Permanent Magnet Electrodynamic Suspension System with a Novel Halbach Array

Cheng Luo,Kunlun Zhang,Jiaheng Duan,Yongzhi Jing 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.2

In this paper, a permanent magnet (PM) electrodynamic suspension (EDS) system with a novel Halbach array is presented, to overcome the uncontrol of the levitation force in the PM EDS system. The novel Halbach array consists by winding normal conductor coils on permanent magnets surface. The 2-D analytical expression of the space static magnetic feld is calculated using Biot-savart law and surface current method. When the vehicle-mounted novel Halbach array moves to cut the conductive plate, the space magnetic feld equations are obtained by establishing equations of magnetic vector potentials using complex Fourier transform of space static magnetic feld. The levitation force and drag force are derived using Maxwell stress tensor method. And a 2-D fnite-element model is built to validate the accuracy of this proposed analytical model. Furthermore, the efects of the main characteristic parameters on the levitation force are analysed.

Characterization of phytochemical profile of rhizome of artificial cultured Polygonatum sibiricum with multiple rhizome buds

Cheng Weiqing,Pan Zhibin,Zheng Hanjing,Luo Gelian,Liu Zhibin,Xu Suli,Lin Junhan 한국응용생명화학회 2023 Applied Biological Chemistry (Appl Biol Chem) Vol.66 No.-

Rhizome of Polygonatum sibiricum is both a renowned traditional Chinese remedy and a commonly consumed delicacy. Due to the escalating demand and excessive overexploitation, there has been a growing interest in the artificial cultivation of this plant in recent years. To assess the therapeutic benefits of artificially cultivated P. sibiricum, it is crucial to identify and classify its phytochemical components, which are the primary bioactive compounds found in its rhizome. In this study, the phytochemical profile of an artificially cultivated P. sibiricum rhizomes with multiple rhizome buds (ACM) was characterized by using untargeted UHPLC-Q-Orbitrap-MS based approach. In addition, two-wild-types P. sibiricum rhizomes, namely the wild-type with multiple rhizome buds (WTM) and the wild-type with single rhizome bud (WTS), were used for comparison. A total of 183 phytochemicals, including 20 alkaloids, 48 flavonoids, 33 phenolic acids, and 82 terpenoids, were tentatively identified. Generally, the phytochemical profile of ACM was comparable to that of WTM and WTS. In specific, most of the identified alkaloids and phenolic acids, and approximately half of the identified terpenoids, were not significantly different. Notably, several phytochemicals with potent therapeutic properties, such as epiberberine, laetanine, sinapic acid, curcumenol, were present in ACM. Additionally, artificial cultivation increased the abundance of geniposide and naringenin, which have been linked to cardioprotective effects. These findings provide valuable insights for the future utilization of artificially cultivated P. sibiricum.

Vascular Endothelial Growth Factor (VEGF) Gene Polymorphisms and Breast Cancer Risk in a Chinese Population

Luo, Ting,Chen, Long,He, Ping,Hu, Qian-Cheng,Zhong, Xiao-Rong,Sun, Yu,Yang, Yuan-Fu,Tian, Ting-Lun,Zheng, Hong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis and thereby involved in the development and progression of solid tumours. Associations between three VEGF gene polymorphisms (-634 G/C, +936 C/T, and +1612 G/A) and breast cancer risk have been extensively studied, but the currently available results are inconclusive. Our aim was to investigate associations between three VEGF gene polymorphisms and breast cancer risk in Chinese Han patients. We performed a hospital-based case-control study including 680 female incident breast cancer patients and 680 female age-matched healthy control subjects. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect the three VEGF gene polymorphisms. We observed that women carriers of +936 TT genotypes [odds ratio (OR) =0.46, 95% confidence interval (CI) = 0.28, 0.76; P=0.002] or 936 T-allele (OR=0.81, 95% CI= 0.68, 0.98; P=0.03) had a protective effect concerning the disease. Our study suggested that the +1612G/A polymorphism was unlikely to be associated with breast cancer risk. The -634CC genotype was significantly associated with high tumor aggressiveness [large tumor size (OR=2.63, 95% CI=1.15, 6.02; P=0.02) and high histologic grade (OR=1.47, 95% CI= 1.06, 2.03; P=0.02)]. The genotypes were not related with other tumor characteristics such as regional or distant metastasis, stage at diagnosis, or estrogen or progesterone receptor status. Our study revealed that the VEGF -634 G/C and +936 C/T gene polymorphisms may be associated with breast cancer in Chinese Han patients.

Computational electromechanical approach for stability/instability of smart system actuated with piezoelectric NEMS

Luo, Zhonghua,Cheng, Xiaoling,Yang, Yuhan Techno-Press 2022 Advances in computational design Vol.7 No.3

In this research, the size-dependent impact of an embedded piezoelectric nanoplate subjected to in-plane loading on free vibration characteristic is studied. The foundation is two-parameter viscoelastic. The nonlocal elasticity is employed in order to capture the influence of size of the plate. By utilizing Hamilton's principle as well as the first- order shear deformation theory, the governing equation and boundary conditions are achieved. Then, using Navier method the equations associated with the free vibration of a plate constructed piezoelectric material under in-plane loads are solved analytically. The presented formulation and solution procedure are validated using other papers. Also, the impacts of nonlocal parameter, mode number, constant of spring, electric potential, and geometry of the nanoplate on the vibrational frequency are examined. As this paper is the first research in which the vibration associated with piezoelectric nanoplate on the basis of FSDT and nonlocal elasticity is investigated analytically, this results can be used in future investigation in this area.

The Study of Current Mode Rectifier Control Technology

Luo Min,Liu Bang-tao,Xia Yu Cheng 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.5

The accumulator battery test requests its system converter to output excellent charging/discharging current. According to special request, PWM converter with current mode control is analyzed and designed in this paper. Morever, a loop-locked control strategy is put forward based on dq coordinate conversion to SVPWM converters in the power accumulator battery testing system. low ripple and fast response testing current in a wide adjustable range is achieved, and high power factor is obtained. Considering resonance of LC filter, the passive damping is designed, which is based on the series resistance of capacitor. Simulation results verify the feasibility and validity of this strategy.

Structure and bioactivity of triterpenoids from the stems of Schisandra sphenanthera

Cheng-Qin Liang,Rong-Hua Luo,Ju-Ming Yan,Yan Li,Xiao-Nian Li,Yi-Ming Shi,Shan-Zhai Shang,Zhong-Hua Gao,Liu-Meng Yang,Yong-Tang Zheng,Wei-Lie Xiao,Hong-Bin Zhang,Han Dong Sun 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.2

Two new triterpenoids, schisphendilactoneA and B (1 and 2), together with three known triterpenoids,were isolated from the stems of Schisandra sphenanthera. Their structures were elucidated by spectroscopic methods,and the absolute configuration of 1 was determined bysingle-crystal X-ray diffraction. Compound 2 showedmoderate inhibitory activity against SW480 cancer cellline, and compound 5 exhibited promising anti-HIV-1activity with EC50 value of 0.52 lg ml-1 and therapeuticindex value of 117.12.