Identification of QTLs associated with the anaerobic germination potential using a set of Oryza nivara introgression lines

Licheng Liu,Xiaoxiang Li,Sanxiong Liu,Jun Min,Wenqiang Liu,Xiaowu Pan,Baohua Fang,Min Hu,Zhongqi Liu,Yongchao Li,Haiqing Zhang 한국유전학회 2021 Genes & Genomics Vol.43 No.4

Background Rice (Oryza sativa L.) is an important crop and a staple food for half of the population around the world. The recent water and labor shortages are encouraging farmers to shift from traditional transplanting to direct-seeding. However, poor germination and slow elongation of the coleoptile constrains large-scale application of direct-seeding. Objective Thisstudy was aimed to investigate the genetic basis of the anaerobic germination(AG) potential using a set of Oryza nivara (O. nivara) introgressionlines (ILs). Methods Inthis study, a total of 131 ILs were developed by introducing O. nivara chromosomesegments into the elite indica rice variety 93-11 through advanced backcrossingand repeated selfng. A high-density genetic map has been previouslyconstructed with 1,070 bin-markers. The seeds of ILs were germinated and usedto measure coleoptile length under normal and anaerobic conditions. QTLsassociated with AG potential were determined in rice. Results Basedon the high-density genetic map of the IL population, two QTLs, qAGP1 and qAGP3 associated with AG tolerance were characterized and locatedon chromosomes 1 and 3, respectively. Each QTL explained 15% of the phenotypic variance.Specifcally, the O. nivara-derived chromosomesegments of the two QTLs were positively tolerance to anaerobic condition byincreasing coleoptile length. In a further analysis of public transcriptomedata, a total of 26 and 36 genes within qAGP1 and qAGP3 were transcriptionallyinduced by anaerobic stress, respectively. Conclusions Utilizationof O. nivara-derived alleles at qAGP1 and qAGP3 can potentially enhance tolerance to anaerobic stress at thegermination stage in rice, thereby accelerating breeding of rice varieties tobe more adaptative for direct-seeding.

Analysis and Optimization of Asymmetric Hybrid Permanent Magnet Motor for Electric Vehicle

Liu Kaiwen,Shi Liwei,Liu Zhengwei,Wang Wenqiang,Ding Hongshan 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.5

An asymmetric hybrid permanent magnet motor (AHPMM) is proposed for the traditional permanent magnet motor (TPMM) with a large amount of rare earth materials and high cogging torque. The equivalent magnetic circuit model of the motor is established and the factors affecting the fluctuation of cogging torque are analyzed. With the objective of reducing the torque ripple and cogging torque of the AHPMM, the motor is parametrically modeled and analyzed, and multi-objective hierarchical optimization of the motor parameters is carried out using a hybrid algorithm combining the response surface algorithm and the single scan method, which ultimately determines the optimal combination of motor dimensional parameters. The electromagnetic performance of the AHPMM compared to the TPMM is analyzed using the finite element method. The results show that, without any decrease in output torque, the use of rare-earth materials is reduced by 18.5%, the cogging torque and the total harmonic distortion of the No-load back EMF waveform are reduced by 0.78 Nm and 4.7% respectively compared to the TPMM. Finally, a prototype motor is manufactured and the validity of the theoretical analysis and design of the AHPMM is verified through experiments.

Enhancing the Specific Activity of Metal Catalysts Toward Oxygen Reduction by Introducing Proton Conductor

Kun Cheng,Xiaobo Liu,Wenqiang Li,Zongkui Kou,Shichun Mu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.5

Enhancing oxygen reduction reaction (ORR) activity and simultaneously reducing usage of noble metal catalysts are significantly important both in fundamental and applied science communities for polymer electrolyte fuel cells (PEFCs). In this work, we confirm the proton conductor (perfluorosulfonic acid, containing -SO3H) can promote the specific activity (Is) of metal catalysts toward ORR. Herein, Pt nanoparticles (NPs) with a small and narrow size distribution are encapsulated with perfluorosulfonic acid through a simple colloidal route. The resulting catalyst obtains about two times (Is) towards ORR than that of the pristine Pt/C. Significantly, the amount of -SO3H groups is controlled by a heat-treatment method to investigate the influence of -SO3H groups on (Is). The results evidence the contribution of -SO3H groups to elevating the ORR specific activity. The mechanism can be ascribed to the -SO3H groups which effectively promote the transfer process of reaction species (e.g., H+, H2O), improving the triple-phase boundary (TPB).

Construction of Glycerol Synthesis Pathway in Klebsiella pneumoniae for Bioconversion of Glucose into 1,3-Propanediol

Hong Zong,Xiaohong Liu,Wenqiang Chen,Bin Zhuge,Jin Sun 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.5

1,3-Propanediol (1,3-PDO) is an important three-carbon compound widely used in new polyester polymer materials. Natural organisms that can produce 1,3- PDO from glycerol were well studied. However, no natural microorganisms found could directly convert glucose to 1,3-PDO due to its insufficient glycerol synthesis pathway. In this study, two essential glycerol synthesis genes, CgGPD gene (encoding glycerol-3-phosphate dehydrogenase from Candida glycerinogenes) and ScGPP2 gene (encoding glycerol-3-phosphatase from Saccharomyces cerevisiae), were expressed in wild-type Klebsiella pneumoniae, a natural 1,3-PDO producers with reduction pathway for 1,3- PDO synthesis from glycerol. The results of fermentation, key enzyme activities, and metabolites analysis confirmed that recombinant K. pneumoniae now possessed a metabolic pathway capable of converting glucose to 1,3-PDO. The strain could produce 1,3-PDO from glucose with a final titer of 17.27 g/L with 40 g/L glucose in the medium, showing a 1.26-fold increase compared with 30 g/L glucose. Also, adding certain concentrations of glycerol could quickly initiate the 1,3-PDO synthetic pathway and promote the accumulation of 1,3-PDO, which could shorten the fermentation cycle. These results have important implications for further studies involving the use of one strain for bioconversion of glucose to 1,3-PDO.

Analytical model for the basement wall horizontally supported by flexible floor diaphragms

Yongjun Lin,Xianzhao Zhang,Kaiqi Liu,Wenqiang Xu 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.79 No.5

Subterranean floors are treated as the rigid lateral support in the current practice for the basement wall design. The structural performance of the basement wall will be influenced by the floor openings, which are inevitable to satisfy building functional requirements. An analytical model for the basement wall being presented is able to analyze the effect of such opening quantitatively. The magnitude of the horizontal support stiffness is determined based on deformation analysis of the diaphragm opening area. Idealized models of the basement wall are continuous beams with various degrees of indeterminacy. The force method is used to deduce the functions for internal forces acting towards the basement wall. The proposed analytical model is verified with results derived by finite element analyses through consideration of various factors, including various numbers of stories, combinations of beam-slab sections, and percentages of floor opening dimensions. The maximum deviations on critical design sections for all prototype basement structures are less than 15.99%. Comparisons with conventional rigid support models are also performed, providing an estimation of the effect of the opening on the mechanical behavior of the basement wall.

Experimental Study on the Damage of Steel Tubular Structural Components by Near-Field Detonations

Wanyue Wang,Shaobo Geng,Hua Wang,Wenqiang Li,Yaling Liu,Jianying Xue,Tingbian Zhan,Ying Gao 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.2

This paper describes three blast-loading trials on three kinds of steel tubular structural components at the same explosive charge and standoff distance. Specimen one is a hollowsteel tube (HST), another is a HST wrapped with glass fibre-reinforced plastic (GFRP) with epoxy resin and the third is a HST infilled with concrete. The main objective of the trials is to investigate the effect of near-field detonations on circular steel tubular components. The experimental data, such as the overpressure time history, front local deformation, rear residual deflection and strain time history, are all recorded and collected. Analysis of the trial results shows that the experimental peak overpressure values of shot 1-3 are all larger than that of numerical simulation. The failure of these three specimens mainly experiences local damage, at the same time, the HST and HST with GFRP exhibit obvious global deformation. With the initiation point at one end of the cylinder explosive, both the maximum depth deformation on the front surface and the maximum residual deflection on the rear surface are all located on the side of the another end of the cylinder explosive. The blast-resistant approach by covering 10-layer GFRP on the surface of the HST can reduce the local damage, the global deformationand the dynamic strain value to certain extent, while the approach by infilling the steel tube with concrete can greatly decrease the local damage and the dynamic strain value and without any global deformation.

Effect of addition of weak acids on CO2 desorption from rich amine solvents

Min Du,Bo Feng,Hui An,Wenqiang Liu,Li Zhang 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.3

Experiments were conducted to study the effect of addition of four weak acids (adipic, suberic, phthalic and sebacic acids) on the regeneration of three types of CO2-loaded rich solvents (Monoethanolamine (MEA), Diethanolamine (DEA) and Methyldiethanolamine (MDEA)). It was found that CO2 could be released faster and in a larger quantity when the amount of acid added to the solvent was increased while other desorption conditions were maintained unchanged. Adipic acid appeared to be more effective than phthalic, suberic and sebacic acids in enhancing solvent regeneration rate. Among the three amines investigated, MEA had the highest CO2 desorption rate, while DEA saved the most energy. The effect of adipic acid residue in the MEA solvent on CO2 absorption was also investigated. The residue acid reduced the absorption capacity of the MEA solvent significantly when the solvent concentration was low and slightly when the concentration was high.

New ZVZCT Bidirectional DC-DC Converter Using Coupled Inductors

Wei Qian,Xi Zhang,Zhe Liu,Wenqiang Jin,Jochen Wiedemann 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In this study, a novel zero voltage zero current transition (ZVZCT) bidirectional DC-DC converter is proposed by employingcoupled inductors. This converter can turn the main switch on at ZVZCT and it can turn it off with zero voltage switching (ZVS)for both the boost and buck modes. These characteristics are obtained by using a simple auxiliary sub-circuit regardless of thepower flow direction. In the boost mode, the auxiliary switch achieves zero current switching (ZCS) turn-on and ZVS turn off. Due to the coupling inductors, this converter can make further efficiency improvements because the resonant energy in thecapacitor or inductor can be transferred to the load. The main diode operates with ZVT turn-on and ZCS turn-off in the boostmode. For the buck mode, there is a releasing circuit to conduct the currents generated by the magnetic flux leakage to the output. The auxiliary switch turns on with ZCS and it turns off with ZVT. The main diode also turns on with ZVT and turns off withZCS. The design method and operation principles of the converter are discussed. A 500 W experimental prototype has been builtand verified by experimental results.