http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Fu‑xiang Cao,Kun‑kun Deng,Cui‑ju Wang,Kai‑bo Nie,Wei Liang,Jian‑feng Fan 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12
The 10 μm 10 vol% SiCp/2024Al composites sheet was successfully fabricated by semi-solid stir casting followed withtwo-step deformation (extrusion and rolling). The two-step thermal deformation solves the sheet rolling formability of theSiCp/2024Al composites produced by stir casting. Compared with the SiCp/2024Al composites prepared by traditional powdermetallurgy, this paper innovatively studied the synergistic enhancement between CuAl2phase and SiCpon the mechanicalproperties. The result shows that the two-step deformation can significantly improve the uniformity of the distribution of SiCpand CuAl2phases. At the same time, the average size of the SiCpand CuAl2phase decreases after the two-step deformation. During the hot extrusion, SiCphas an obvious hindrance to the refinement of the CuAl2phase. Moreover, the SiCp/2024Alcomposites sheet exhibits excellent yield strength (295 MPa), ultimate tensile strength (489 MPa), and elongation (10.42%). The performance improvement of SiCp/2024Al after two-step thermal deformation is mainly attributed to the improvedinterface bonding strength of SiCp-2024 Al matrix, the refined SiCpand the more uniform distribution of SiCp.
Modeling of Piezoelectric Langevin Transducers by Using Mixed Transfer Matrix Methods
Bo Fu,Chao Li,Jianming Zhang,Zhenwei Huang,Tobias Hemsel 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.41
In the modeling of piezoelectric Langevin transducers using the usual transfer matrix methods, some simplifications have been adopted. This leads to a reduction in the model quality. A mixed transfer matrix method is employed in the modeling of Langevin transducers, where the pre-stressed bolt is modeled as a separate four-pole element connected to other elements in parallel. Based on the mixed transfer matrix method, the four (six)-pole element description of the piezoelectric Langevin transducer is built up, and the total transfer matrix relation is derived. The resonance frequencies of the transducer are calculated and then measured using an impedance analyzer (HP4192). Experimental results show that the mixed transfer matrix method has better modeling quality than the usual transfer matrix method for the vibration analysis of piezoelectric Langevin transducers.
Fu, Bo,Ren, Liang,Liu, Di,Ma, Jian-Zhang,An, Tie-Zhu,Yang, Xiu-Qin,Ma, Hong,Zhang, Dong-Jie,Guo, Zhen-Hua,Guo, Yun-Yun,Zhu, Meng,Bai, Jing Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.12
The in vitro maturation (IVM) efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+) oocytes with low glucose-6-phosphate dehydrogenase (G6PDH) activity have shown superior quality than BCB negative (-) oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG) migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9) and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB- oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.
Zhijian Fu,Li-Jun Jia,JIHONG XIA,Hai-Bo Ruan,Ke Tang,Yong Pu,Zhao-Yi Zeng,Dian-Yong Tang,Bo Kong,Qi-Feng Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6
The equilibrium structure and electronic properties of four ultrathin free-standing pentagonal and hexagonal noble metal nanowires, that is, copper nanowires (CuNWs), silver nanowires (AgNWs), gold nanowires (AuNWs) and platinum nanowires (PtNWs), have been studied comprehensively by adopting a first-principles simulation based on the density-functional theory. The staggered topologies are more stable than the eclipsed ones by analyzing the bonding energy. The staggered ones with a linear atom chain in the center of the pentagonal or hexagons topologies are the preferred structures for CuNWs and AgNWs, but the staggered ones without a linear atom chain in the center of the pentagon or hexagon are the preferred structures for AuNWs and PtNWs due to the increasing core–core repulsions. The calculated electronic band structures and density of states present that all the noble metal nanowires are metallic. The projected densities of states (PDOS) of dominant d-states and the charge density show that the narrower d-state moved to the Fermi energy and metallic bonding character for all the noble metal nanowires.
Enhancement of Virus-induced Gene Silencing in Tomato by Low Temperature and Low Humidity
Da-Qi Fu,Ben-Zhong Zhu,Hong-Liang Zhu,Hong-Xing Zhang,Yuan-Hong Xie,Wei-Bo Jiang,Xiao-Dan Zhao,Yun-Bo Luo 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.1
Virus-induced gene silencing (VIGS) is an attractive reverse-genetics tool for studying gene function in plants. We showed that silencing of a phytoene desaturase (PDS) gene is maintained throughout TRV-PDSinoculated tomato plants as well as in their flowers and fruit and is enhanced by low temperature (15°C) and low humidity (30%). RT-PCR analysis of the PDS gene revealed a dramatic reduction in the level of PDS mRNA in leaves, flowers and fruits. Silencing of PDS results in the accumulation of phytoene, the desaturase substrate. In addition, the content of chlorophyll a, chlorophyll b and total chlorophyll in the leaves of PDS-silenced plants was reduced by more than 90%. We also silenced the LeEIN2 gene by infecting seedlings, and this suppressed fruit ripenning. We conclude that this VIGS approach should facilitate large-scale functional analysis of genes involved in the development and ripening of tomato.
Bo Ren,Zhi-Wei He,Yong-li Sun,Fu-Dong Wang 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.8
Based on the generalized bilinear operators in a prime number $p=3$, we introduce a (2+1)-dimensional coupled nonlinear partial differential like equation. By combining an exponential function with a quadratic function, an interaction between a lump wave and a one-kink soliton is generated. In addition, an interaction between a lump wave and a two-kink soliton, which is called a special rogue wave, can be obtained by adding two additional exponential functions. The dynamic properties of these interactions are depicted by selecting appropriate parameters.
Bo Gao,Hong-Tao Xue,Fu-Ling Tang,Yu-Wen Cheng 한국물리학회 2017 Current Applied Physics Vol.17 No.11
First-principles plane-wave calculations were employed to study the phase transitions, electronic and optical properties of chalcopyrite CuInS2 (CIS) under pressure, which is a promising semiconductor compound material for nonlinear optical, photovoltaic and bio-applications. From the variations of Gibbs free energy and volume with pressure, we confirmed an experimentally found phase transformation of CIS from tetragonal I42d structure into the cubic Fm3m phase. It occurs at 7.9 GPa with a volume reduction of 15.6%, which are comparable with the experimental values of 9.5 GPa and 12%. A new possible phase transition of CIS from the cubic Fm3m structure to the orthorhombic Cmcm structure under higher pressure was predicted occurring at 49.6 GPa with a volume reduction about 0.64%. Using the more accurate HSE06 functional, we found that the growth rate of energy gap with pressure (dEg/dP) for the I42d phase is about 24.8 meV/GPa, very close to the experimental value of 24 meV/GPa. The calculated electronic properties for Fm3m and Cmcm phases show that CIS is a metallic material under high pressure, rather than a semiconductor. The optical absorption spectra indicate that with the increase of pressure the absorption edge of CIS becomes smaller while the optical energy gap is larger.
Fu Li,Yongchun Dong,Weimin Kang,Bo-wen Cheng,Xiang Qu,Guixin Cui 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.12
Two transition metal ions (Fe3+ and Cu2+) and a rare earth metal ion (Ce3+) were selected to coordinate with amidoximated polyacrylonitrile (PAN) nanofibrous membrane for preparing three metal modified PAN nanofibrous membrane complexes (M-AO-n-PANs, M = Fe, Cu, or Ce) as the heterogeneous Fenton catalysts for the dye degradation in water under visible irradiation. The coordination kinetics of three metal ions with modified PAN nanofibrous membranes was studied and the catalytic properties of the resulting complexes were also compared. The results indicated that increasing metal ion concentrations in solution or higher coordination temperature led to a significant increase in metal content, particularly in Fe and Cu contents of the complexes. Their coordination process could be described using Langmuir isotherm and pseudo-second-order kinetic equations. Moreover, Fe-AO-n-PAN had the best photocatalytic efficiency for the dye degradation in acidic medium, but a lower photocatalytic activity than Cu-AO-n-PAN in alkali medium.
( Bo Wang ),( Ying Yan ),( Jing Xu ),( Xiaoyan Fu ),( Hongjuan Han ),( Jianjie Gao ),( Zhenjun Li ),( Lijuan Wang ),( Yongsheng Tian ),( Rihe Peng ),( Quanhong Yao ) 한국미생물 · 생명공학회 2018 Journal of microbiology and biotechnology Vol.28 No.12
Laccases can oxidize a variety of phenolic and non-phenolic substrates including synthetic dyes. In this research, a laccase gene Lcc9 from Laccaria bicolor was chemically synthesized and optimized to heterogeneous expression in Pichia pastoris and Arabidopsis thaliana. The properties of recombinant laccase expressed by P. pastoris were investigated. The laccase activity was optimal at 3.6 pH and 40°C. It exhibited K<sub>m</sub> and V<sub>max</sub> values of 0.565 mmol l<sup>-1</sup> and 1.51 μmol l<sup>-1</sup> min<sup>-1</sup> for ABTS respectively. As compared with untransformed control plants, the laccase activity in crude extracts of transgenic lines exhibited a 5.4 to 12.4-fold increase. Both laccases expressed in transgenic P. pastoris or A. thaliana could decolorize crystal violet. These results indicated that L. bicolor laccase gene may be transgenically exploited in fungi or plants for dye decolorization.