Effects of the silencing of CmMET1 by RNA interference in chrysanthemum (Chrysanthemum morifolium)

Shuailei Li,Mangmang Li,Zhongai Li,Yi Zhu,Hongxu Ding,Xiaoxuan Fan,Fei Li,Zicheng Wang 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.1

DNA methylation is an epigenetic modification involving many biological processes. It is known that epigenetic mechanisms such as cytosine methylation play a pivotal role in regulating plant development. In this current study, a conservative domainspliced hairpin RNA (ihpRNA) plant expression vector aimed at gene of DNA METHYLTRANSFERASE1 (CmMET1) has been constructed. Transgenic chrysanthemum materials (Zijingling) were obtained by Agrobacterium-mediated transformation with expression vectors. Transgenic plants were used as rootstock, grafted onto non-transgenic the scions [Guoqinghong (GQH) and Huanshuijinqiu (HSJQ)], which silencing CmMET1 gene, and exhibited the early flower phenotypes. A highperformance liquid chromatography analysis indicated that the decrease of CmMET1 expression decreased the methylation level of genomic DNA. Similarly, a quantitative real-time polymerase chain reaction analysis revealed that CmMET1 expression levels decreased in transgenic chrysanthemum plants and in the scions grafted onto transgenic plants. This decrease of CmMET1 expression upregulated the expression of the methyltransferase gene, METHYLTRANSFERASE2 (CmDRM2), but downregulated the expression of the demethylating enzyme gene, DEMETER (CmDME), while the CHROMOMETHYLASEA (CmCMT3) expression level remained low and could be almost undetectable. Among the CmFT-likes genes that affect flowering time, CmFTL1 expression was downregulated, as well as CmFTL2 and CmFTL3 expression levels which were upregulated. Our data indicated that silencing CmMET1 could decrease plant height, change the phenotype of chrysanthemum, and promote earlier flowering. The transgenic plants bloomed 8 days earlier. GQH and HSJQ scions grafted onto transgenic plants were 12 and 9 days earlier than the scions grafted onto non-transgenic plants, respectively. Overall, the results have some meanings for promoting the flowering of chrysanthemum scion varieties using genetic modified rootstock.

Cherish Life, Stay Away From Drugs

Li Hongxu 한국콘텐츠학회 2016 ICCC International Digital Design Invitation Exhib Vol.2016 No.5

Rollover Prediction and Control Strategy Based on Experiment for Tractor Semitrailer Fitted with Hydraulically Interconnected Suspension

Hongxue Li,Liangsheng Liu,Longxin Zhen,Xianyi Xie,Yi Xu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.1

Hydraulically interconnected suspension (HIS) system has theoretically and experimentally been proved to suppress rollover of non-articulated vehicle, but lacking of vibration studies on more complex nonlinear systems such as multi-axle combination vehicle. Hence, this paper presents rollover threshold prediction and active disturbance rejection controller (ADRC) of a tractor semitrailer fitted with HIS based on experimental test to reduce instability of mechanical system. Firstly, a roll resistant verification of a tractor semitrailer fitted with HIS is conducted under a steady circle experiment. Furthermore, the prediction for rollover threshold to extreme maneuver is presented by incorporating robust Kalman filter (RKF) and Back Propagation neural network with genetic algorithm (GA-BP) that are both designed. Finally, an ADRC control is proposed based on control model reduced by applying least square identification and model reduction method. The results are obtained including three aspects: experimental results verify the superior anti-roll performance of vehicle fitted with HIS in comparison with traditional vehicle and are also used to assist the subsequent prediction at high speed. Prediction results highlight that the RKF algorithm performs better filtering accuracy over KF, UKF and PF methods and developed GA-BP supply the higher precision compared with the conventional BP method for the prediction, by which the lateral acceleration threshold is achieved. The results of control show ADRC control strategy obviously has faster response and smaller overshoot than fuzzy PID and regular PID controller for the stability of system.

Capacitor voltage balancing method for hybrid modular multilevel converters based on second‑harmonic voltage injection

Hongxu Li,Qin Wang,Qunfang Wu,Lan Xiao,Jinbo Li 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.4

Due to different output voltages, capacitor voltage imbalance occurs between half-bridge sub-modules (HBSM) and fullbridge sub-modules (FBSM) in hybrid modular multilevel converters (MMCs) under a boosted modulation index (m). To address this issue, a capacitor voltage balancing method based on second-harmonic voltage injection is proposed in this paper. The mechanism of the proposed method is to eliminate the DC component in the charging power of sub-modules under the restriction that the HBSM cannot output negative voltage. The proposed method is divided into two cases according to m. Case 1 is used when m ≤ 1.4, while Case 2 is implemented when m > 1.4. When compared with similar capacitor voltage balancing methods, the proposed SVI method has a simpler structure that can greatly reduce the number of computations. Simulation and experimental results verify the effectiveness of the proposed capacitor voltage balancing method.

Prevents AIDS Alarm Always Sounds

Hongxu Li 한국콘텐츠학회 2015 ICCC International Digital Design Invitation Exhib Vol.2015 No.12

Experimental Investigation of Output Current Variation in Biased Silicon-based Quadrant Photodetector

Hongxu Liu,Di Wang,Chenang Li,Guangyong Jin 한국광학회 2020 Current Optics and Photonics Vol.4 No.4

We report on the relationship between output current for quadrant photodetector (QPD) and bias voltage in silicon-based p-i-n (positive-intrinsic-negative) QPD examined using millisecond pulse laser (ms pulse laser) irradiation. The mechanism governing the relationship was further studied experimentally. The output current curves were obtained by carrying out QPD under different bias voltages (0~40 V) irradiated by ms pulse laser. Compared to other photodetectors, the relaxation was created in the output current for QPD which is never present in other photodetectors, such as PIN and avalanche photodetector (APD), and the maximum value of relaxation was from 6.8 to 38.0 µA, the amplitude of relaxation increases with bias value. The mechanism behind this relaxation phenomenon can be ascribed to the bias voltage induced Joule heating effect. With bias voltage increasing, the temperature in a QPD device will increase accordingly, which makes carriers in a QPD move more dramatically, and thus leads to the formation of such relaxation.

A Discrete-time Projection Neural Network for Solving Convex Quadratic Programming Problems with Hybrid Constraints

Fengqiu Liu,Jianmin Wang,Hongxu Zhang,Pengfei Li 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.1

A new discrete-time neural network is proposed for solving convex quadratic programming problems with hybrid constraints. Based on the projection operator and convex optimization technologies, a single layer discrete-time neural network with monotonic descent dynamic step sizes is constructed. It is proved that the equilibrium points of the discrete-time neural network are globally exponentially convergent to the optimal solutions of the programming problem. Moreover, an algorithm is given based on the proposed neural network and the scheme of backtracking step-size adaptation. Finally, the proposed algorithm is applied to three types of quadratic programming problems and the gas oven identification via a support vector regression algorithm. The numerical experiments are performed to show the correctness and effectiveness of the results in this paper.

Cyclic Behavior of Sand under Traffic Loading with ‘Inclined’ Consolidation

Lin Guo,Yuan Fang,Tingyu Wu,Jun Wang,Hongxu Jin,Li Shi 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.5

To investigate the vertical strain development of sand under traffic loading after the process of ‘inclined’ consolidation, a series of cyclic drained tests were carried out by using a hollow cylinder apparatus. Three parameters were considered in this paper: initial consolidation angle, vertical cyclic stress ratio and cyclic torsional stress ratio. Test results show that the vertical strain under traffic loading path is larger than that of specimens whose cyclic torsional stress ratio is equal to 0 in the same situation. Furthermore, the vertical stain will decrease with the increase of consolidating inclination in the situation of same values of vertical cyclic stress ratio and cyclic torsional stress ratio. When initial consolidation angle is equal to 0o and 22.5o, the vertical strain will increase with increasing value of cyclic torsional stress ratio, while the effect of cyclic torsional stress ratio on vertical strain will be less significant when initial consolidation angle is equal to 45o. Moreover the trend that vertical strain increases with increasing value of cyclic torsional stress ratio will be more significant for a larger value of vertical cyclic stress ratio.