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.

Research on Li0.3Na0.18K0.52NO3 promoted Mg20Al-CO3 LDH/GO composites for CO2 capture

Ying Yang,Kai Chen,Liang Huang,Min Li,Taiping Zhang,Mi Zhong,Ping Ning,Junya Wang,Shikun Wen 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.102 No.-

It has been reported that the addition of graphene oxide (GO) can increase the dispersion and heterogeneousnucleation of layered double hydroxide (LDH), thus providing more active sites, which is more conduciveto CO2 adsorption. Herein, we reported alkali metal nitrates ((Li0.3Na0.18K0.52)NO3) promoted LDHand GO composites (LDH/GO) as adsorbents for CO2 capture. The influence of mass ratio of LDH to GO, theimpregnation ratio of alkali metal nitrates, the calcination and adsorption temperature, as well as thecycling stability were investigated systematically. The results indicated that the CO2 capture capacityof LDH/GO composite with 30 mol% (Li0.3Na0.18K0.52)NO3 could reach 4.51 mmol g 1, which was 5.86times higher than LDH/GO1 without loading alkali metal nitrates. Moreover, it had outstanding CO2adsorption capacity in the range from 200 C to 320 C. In addition, the cyclic adsorption and desorptiontest manifested that the CO2 uptake of the material can reach 3.07 mmol g 1 after 22 cycles. We believethat this study will give a significant contribution to fabrication of LDH based composites as CO2 adsorbentsin future study.

Realizing highly efficient multicolor tunable emissions from Tb³⁺ and Eu³⁺ co-doped CaGd₂(WO₄)₄ phosphors via energy transfer by single ultraviolet excitation for lighting and display applications

Huang, Xiaoyong,Li, Bin,Du, Peng,Guo, Heng,Cao, Renping,Yu, Jae Su,Wang, Kai,Sun, Xiao Wei Elsevier 2018 Dyes and pigments Vol.151 No.-

<P><B>Abstract</B></P> <P>In this paper, we reported on multicolor emission tuning in Tb<SUP>3+</SUP> and Eu<SUP>3+</SUP> co-doped CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB> phosphors prepared by a traditional high-temperature solid-state reaction. Upon 380 nm ultraviolet excitation, the emission color of CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> phosphors can be readily tuned from green to yellow, orange and finally to pure red through varying the concentration ratio of Eu<SUP>3+</SUP> and Tb<SUP>3+</SUP> ions. The energy transfer mechanism from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP> was systematically investigated by photoluminescence spectra, luminescence decay times, and time-resolved spectra. The internal quantum efficiencies of these phosphors were measured, and their thermal stability was also studied. A prototype white light-emitting diode (LED) device was fabricated by using an ultraviolet chip combined with a blend of blue-emitting BaMgAl<SUB>10</SUB>O<SUB>l7</SUB>:Eu<SUP>2+</SUP> phosphors, green-emitting BaSrSiO<SUB>4</SUB>:Eu<SUP>2+</SUP> phosphors, and red-emitting CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:50%Tb<SUP>3+</SUP>,50%Eu<SUP>3+</SUP> phosphors. All the results indicate that the CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> has great potential application in lighting and displays.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> showed efficient energy-transfer from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP>. </LI> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> exhibited tunable color emission under 380 nm excitation. </LI> <LI> The energy-transfer mechanism was studied in detail. </LI> <LI> Quantum efficiency and thermal stability were investigated. </LI> <LI> The proof-of-concept LED lamps were fabricated by employing phosphors and UV LEDs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Salt-controlled dissolution in pigment cathode for high-capacity and long-life magnesium organic batteries

Cui, Lianmeng,Zhou, Limin,Zhang, Kai,Xiong, Fangyu,Tan, Shuangshuang,Li, Maosheng,An, Qinyou,Kang, Yong-Mook,Mai, Liqiang Elsevier 2019 Nano energy Vol.65 No.-

<P><B>Abstract</B></P> <P>Benefiting from high volumetric energy density and generally dendrite-free growth of Mg metal, rechargeable magnesium batteries (MBs) become a promising next-generation energy storage system. Organic electrode materials, with characteristic of sustainable resource and flexible structure, have been widely studied in alkali metal ion batteries, but are rarely reported in MBs. Herein, we demonstrate that 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) serves as a cathode material for MBs in non-aqueous system, which realizes a fast diffusion kinetics and remarkable Mg-storage performance through a salt-dissolution inhibition approach for the electrolyte. The PTCDA exhibits a reversible capacity of 126 mAh g<SUP>−1</SUP> (at 200 mA g<SUP>−1</SUP>), excellent rate performance, and good cycling stability (100 mAh g<SUP>−1</SUP> even after 150 cycles). Furthermore, the evolution mechanism of the PTCDA electrode based on the transformation between carbonyl groups (CO) and enolate groups (C–O) is revealed by <I>ex-situ</I> phase characterization and functional group analysis. Besides, the dissolution inhibition of the PTCDA could also be realized through the incorporation of other soluble salt (KCl or NaCl) into all phenyl complex (APC) electrolyte, resulting in an enhanced cycling capacity. Considering the designable configuration of the organic materials, this work would pave way for their utilization on multi-valent ion batteries and provide efficient strategy to realize high voltage and satisfied cycle life.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The magnesium anode in organic system was realized combined with the solubility inhibition of the host materials. </LI> <LI> Compared with other inorganic cathode materials, the PTCDA is eligible to offset the defect of Mg<SUP>2+</SUP> transport dynamics. </LI> <LI> Compared with other Mg-storage materials reported, the PTCDA demonstrates a high working voltage plateau and a small polarization. </LI> <LI> The electrochemical mechanism of the PTCDA is proved to be the transformation between carbonyl groups and enolate groups. </LI> <LI> The incorporation of dissolvable salts inhibited the dissolution of the PTCDA. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Activation of formyl CH and hydroxyl OH bonds in HMF by the CuO(1 1 1) and Co₃O₄(1 1 0) surfaces: A DFT study

Ren, Jun,Song, Kai-he,Li, Zhenhuan,Wang, Qiang,Li, Jun,Wang, Yingxiong,Li, Debao,Kim, Chan Kyung Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.456 No.-

<P><B>Abstract</B></P> <P>The first principle calculations with on-site Coulomb repulsion U terms were carried out to investigate the 5-hydroxymethylfurfural (HMF) adsorption on the CuO(1 1 1) and Co<SUB>3</SUB>O<SUB>4</SUB>(1 1 0) surfaces, two widely used oxidation catalysts. The adsorption of HMF molecule is energetically favoured in both cases, and HMF is more inclined to bridge adsorption via hydroxyl and formyl groups binding with surface O and metal sites. Moreover, the adsorption energy relies on both the coordination type of surface lattice oxygen to which the H atom binds and the formation of H-bond involving hydroxyl and formyl groups on the adsorbed HMF. Also, the hydroxyl OH bond breaking is very easy and is likely to be the first step in HMF oxidation, and then the OH insertion reaction to produce 2,5-furandicarboxylic acid (FDCA). The corresponding experimental results also show that the CuO and Co<SUB>3</SUB>O<SUB>4</SUB> surfaces are promising candidate catalysts.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CuO(1 1 1) and Co<SUB>3</SUB>O<SUB>4</SUB>(1 1 0) surfaces catalyze the oxidation of 5-hydroxymethylfurfural (HMF). </LI> <LI> Initial binding was formed through bridged-adsorption with O atoms in HMF. </LI> <LI> Oxidation reaction proceeds through the OH bond breaking pathway. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Schematic potential energy diagram for the formyl CH and hydroxyl OH bonds of HMF dissociation on CuO(1 1 1) and Co<SUB>3</SUB>O<SUB>4</SUB>(1 1 0) surfaces. Obviously, the hydroxyl OH bond breaking is easier than that of the formyl CH bond on the two surfaces, which indicates the first step of oxidation of HMF to FDCA should be hydroxyl OH bond breaking.</P> <P>[DISPLAY OMISSION]</P>

Bond-Slip Behaviors Between BFRP Bar and Ecological High Ductility Concrete Using the Beam Test

Li-Juan Chai,Li-Ping Guo,Bo Chen,Zhu Li,Rui Ma,Kai Li 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.12

To better understand the design parameters of bridge deck link slab made by basalt fiber reinforced polymer (BFRP) bar and ecological high ductility concrete (Eco-HDC), the bond behaviors of BFRP bar embedded in Eco-HDC using beam test based on RILEM standard were studied. The beam specimens had variable factors namely diameter of BFRP bar, embedment length and cover thickness. The results indicate that most beam specimens display a failure mode of BFRP bar pulled out with specimen splitting. Besides, with the increase of diameter and embedment length, the bond strength decreases. While as the cover thickness increases, the bond strength and first bond stress show an increasing trend. The free end slip increases as the embedment length or cover thickness increases. In addition, the strain at loaded end is larger than that at free end as the load increases. Moreover, the formulas of bond strength and peak slip are proposed based on the test data of specimens. At last, embedment length and cover thickness of BFRP bar in the bridge deck link slab are recommended.

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

Kai Sun,Rui-Juan Han,Li-Jun Ma,Li-Jun Wang,Li-Gang Li,Jiu-Hong Chen 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Materials and Methods: Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 ± 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. Results: There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 ± 0.306 [group A] vs. 1.084 ± 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 ± 0.16 mSv in group A and 7.1 ± 1.05 mSv in group B (p = 0.001). Conclusion: In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure. Objective: To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Materials and Methods: Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 ± 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. Results: There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 ± 0.306 [group A] vs. 1.084 ± 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 ± 0.16 mSv in group A and 7.1 ± 1.05 mSv in group B (p = 0.001). Conclusion: In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

Beam position measurement system at HIRFL-CSRm

Li Min,Xiao Guoqing,Mao Ruishi,Zhao Tiecheng,Yuan Youjin,Li Weilong,Zhou Kai,Kang Xincai,Li Peng,Li Juan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4

Beam position measurement system can not only provide the beam position monitoring, but also be used for global orbit correction to reduce beam loss risk and maximize acceptance. The Beam Position Monitors (BPM) are installed along the synchrotron to acquire beam position with the front-end electronics and data acquisition system (DAQ). To realize high precision orbit measurement in the main heavy ion synchrotron and cooling storage ring of heavy-ion research facility in Lanzhou (HIRFL-CSRm), a series of alignment and calibration work has been implemented on the BPM and its DAQ system. This paper analyzed the tests performed in the laboratory as well as with beam based on the developed algorithms and hardware. Several filtering algorithms were designed and implemented on the acquired BPM raw data, then the beam position and resolution were calculated and analyzed. The results show that the position precision was significantly improved from more than 100 μm to about 50 μm by implementing the new designed filtering algorithm. According to the analyzation of the measurement results and upcoming physical requirements, further upgrade scheme for the BPM DAQ system of CSRm based on field programmable gate array (FPGA) technology was proposed and discussed.

Measurement and Theoretical Calculation Confirm the Improvement of T7651 Aging State Influenced Precipitation Characteristics on Fatigue Crack Propagation Resistance in an Al–Zn–Mg–Cu Alloy

Kai Wen,Baiqing Xiong,Yongan Zhang,Zhihui Li,Xiwu Li,Lizhen Yan,Hongwei Yan,Hongwei Liu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Precipitation characteristics influencing fatigue crack propagation contained matrix precipitate, grain boundary precipitateand precipitate free zone for Al–Zn–Mg–Cu alloys. Over-aging treatment could effectively regulate precipitation and then tobe able to change fatigue crack propagation behavior compared with the peak aging state. In the current work, typical T651and T7651 aging tempers of the alloy were extracted via hardness, electrical conductivity and mechanical properties underone-step and two-step aging treatments. Fatigue crack propagation (FCP) rate under them was tested and correspondingprecipitation characteristics and fracture morphology were observed. The results indicated that fatigue crack propagationresistance for the T7651 temper possessed an obvious improvement on the side of that for the T651 temper, which was alsosupported by fracture appearance, including tearing ridge, tearing dimple and fatigue striation. The precipitation observationshowed that the T651 alloy contained GPI zone, GPII zone and ηʹ phase while the T7651 alloy possessed ηʹ phase and η phase.Compared with the T651 temper, matrix precipitate for the T7651 temper distinctly owed an expanding of size distributionand an enlargement of average size while cuttable phase still remained the dominance for both tempers. Grain boundaryprecipitate and precipitate free zone manifested no obvious difference between the two aging tempers. Cut and bypass mechanismsof dislocation–precipitate interactions were used for explanation and it revealed the reinforced cuttable phase was infavor of enhancing fatigue crack propagation resistance. A theoretical model which directly correlated FCP rate with matrixprecipitate characteristics was employed to calculate FCP rate by substituting quantitative precipitate characteristics and thecalculation results were vaguely consistent with the experimental measurement, which proved its reliability and feasibility.

Performance Analysis of Three-Phase Phase-Locked Loops for Distorted and Unbalanced Grids

Li, Kai,Bo, An,Zheng, Hong,Sun, Ningbo The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

This paper studies the performances of five typical Phase-locked Loops (PLLs) for distorted and unbalanced grid, which are the Decoupled Double Synchronous Reference Frame PLL (DDSRF-PLL), Double Second-Order Generalized Integrator PLL (DSOGI-PLL), Double Second-Order Generalized Integrator Frequency-Lock Loop (DSOGI-FLL), Double Inverse Park Transformation PLL (DIPT-PLL) and Complex Coefficient Filter based PLL (CCF-PLL). Firstly, the principles of each method are meticulously analyzed and their unified small-signal models are proposed to reveal their interior relations and design control parameters. Then the performances are compared by simulations and experiments to investigate their dynamic and steady-state performances under the conditions of a grid voltage with a negative sequence component, a voltage drop and a frequency step. Finally, the merits and drawbacks of each PLL are given. The compared results provide a guide for the application of current control, low voltage ride through (LVRT), and unintentional islanding detection.