Explicit formulas for the Bergman kernel on certain Forelli-Rudin construction

Liyou Zhang,An Wang,Qingbin Li 대한수학회 2012 대한수학회지 Vol.49 No.1

In this note, we present certain circular domain, named Fore\-lli-Rudin construction or Hua construction, which is built on Cartan domains. We compute the explicit Bergman kernel for it and get the corresponding weighted Bergman kernel on its base.

EXPLICIT FORMULAS FOR THE BERGMAN KERNEL ON CERTAIN FORELLI-RUDIN CONSTRUCTION

Zhang, Liyou,Wang, An,Li, Qingbin Korean Mathematical Society 2012 대한수학회지 Vol.49 No.1

In this note, we present certain circular domain, named Forelli-Rudin construction or Hua construction, which is built on Cartan domains. We compute the explicit Bergman kernel for it and get the corresponding weighted Bergman kernel on its base.

Parameter identification of the Bouc-Wen model for the magnetorheological damper using fireworks algorithm

Xiaoliang Chen,Liyou Xu,Shuai Zhang,Sixia Zhao,Kui Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

To solve the problems of low identification accuracy and complex identification methods in the Bouc-Wen model of the magnetorheological (MR) damper, a new parameter identification method using the fireworks algorithm (FWA) is proposed. According to the experimental results of the dynamic characteristics of the MR damper and the simulation data of the Bouc-Wen model, the FWA is used to identify the seven parameters of the Bouc-Wen model. On the basis of the relationship between the identification results and the command current, the current-controlled Bouc-Wen model (I-Bouc-Wen model) is constructed and compared with the experimental results under different sinusoidal excitation frequencies. Compared with the genetic algorithm (GA), differential evolution (DE) algorithm, and particle swarm optimization (PSO) algorithm, the FWA has the advantage of faster convergence, shorter calculation time, and higher stability in solving the parameter identification problem of the highly nonlinear hysteretic model. Under three harmonic excitations, the average calculation accuracies of the IBouc-Wen model reache 88.64 %, 90.45 %, and 81.28 %, respectively, and the dynamic characteristic curve of the model is in basic agreement with the experimental results. It can be used for the subsequent controller design and simulation research and lay a foundation for applying the parameterized model of the MR damper in vibration reduction control.

On the uniform squeezing property of bounded convex domains in ℂn

Kim, Kang-Tae,Zhang, Liyou Mathematical Sciences Publishers 2016 Pacific journal of mathematics Vol.282 No.2

Removal of cobalt ions from aqueous solution by Ag/Fe bimetallic nanoparticles

Huang, Jiarui,Fang, Fang,Wang, Liyou,Shim, Jae-Jin Taylor Francis 2015 Desalination and Water Treatment Vol.56 No.8

Preparation of porous flower-like SnO₂ micro/nano structures and their enhanced gas sensing property

Ren, Haibo,Zhao, Wei,Wang, Liyou,Ryu, Si Ok,Gu, Cuiping Elsevier 2015 JOURNAL OF ALLOYS AND COMPOUNDS Vol.653 No.-

<P><B>Abstract</B></P> <P>Porous flower-like tin oxide (SnO<SUB>2</SUB>) structures were obtained using a hydrothermal method combined with a subsequent calcination and acid-washing process. The morphologies and crystal structures of the products were characterized by field emission scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller N<SUB>2</SUB> adsorption-desorption analyses. The process of inducing porosity begins with a flower-like nickel tin sulfur precursor. Thermal decomposition of this flower-like nickel tin sulfur precursor leads to an intimate mixture of porous flower-like NiO/SnO<SUB>2</SUB> hybrids. Porous SnO<SUB>2</SUB> flowers were obtained after removing the cubic phase NiO by an acid-washing process. Furthermore, the gas sensing properties of the as-prepared porous SnO<SUB>2</SUB> flowers to VOCs, such as ethanol, formaldehyde, benzene, toluene, and acetone, were investigated. The porous SnO<SUB>2</SUB> flowers showed a good response and reversibility to some organic vapors, such as ethanol and formaldehyde. The sensing responses to 100 ppm ethanol and formaldehyde were 42.4 and 24.8, respectively. The sensors also exhibited a good response to benzene, toluene, methanol, and 2-propanol. The relationship between the gas-sensing properties and the microstructure of the as-prepared flower-like SnO<SUB>2</SUB> structures was also examined.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Flower-like nickel tin sulfur structures were synthesized by hydrothermal method. </LI> <LI> Porous SnO<SUB>2</SUB> microflowers were obtained by treatment of the precursor. </LI> <LI> Porous SnO<SUB>2</SUB> microflowers exhibited excellent sensing properties to some gases. </LI> <LI> Excellent gas-sensing properties were attributed to the special 3D structures. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Controlled synthesis of porous Ni-doped SnO₂ microstructures and their enhanced gas sensing properties

Gu, Cuiping,Guan, Wenmei,Liu, Xiaosi,Gao, Lvlv,Wang, Liyou,Shim, Jae-Jin,Huang, Jiarui ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.692 No.-

<P><B>Abstract</B></P> <P>Porous Ni-doped SnO<SUB>2</SUB> microspheres and microcubes were obtained via a facile chemical solution route followed by calcination and acid-washing process. Their structural and morphological evolution was characterized using a range of techniques. The process of inducing porosity began with crystalline single-phase NiSn(OH)<SUB>6</SUB> precursors formed by the co-precipitation of metal ions from an aqueous solution. Thermal decomposition of the precursors led to an intimate mixture of cubic phase NiO and tetragonal phase SnO<SUB>2</SUB>. The Ni-doped SnO<SUB>2</SUB> microspheres and microcubes were obtained after a simple acid-washing process. A decomposition–aggregation–dissolution process was proposed to explain the formation of these structures. The gas-sensing properties of the as-prepared porous Ni-doped SnO<SUB>2</SUB> microspheres and microcubes for toxic volatile organic compounds, such as formaldehyde, ethanol, benzene, methanol, acetone, and toluene, were investigated. The enhanced sensing performance of the porous Ni-doped SnO<SUB>2</SUB> microspheres was demonstrated. The detection limits of formaldehyde and ethanol were approximately 0.17 and 0.09 ppm (signal-to-noise ratio, S/N = 3), respectively. The enhanced sensing performance of the porous Ni-doped SnO<SUB>2</SUB> microspheres was attributed to their Ni-dopant, unique porous structure and large surface area.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous Ni-doped SnO<SUB>2</SUB> microstructures were obtained by treatment of the precursors. </LI> <LI> Porous Ni-doped SnO<SUB>2</SUB> microstructures exhibited excellent gas-sensing properties. </LI> <LI> Excellent gas-sensing properties were attributed to the Ni-dopant and 3D structures. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Porous Ni-doped SnO<SUB>2</SUB> microspheres and microcubes, obtained by a facile chemical solution route followed by calcination and acid-washing, showed excellent gas-sensing performances.</P> <P>[DISPLAY OMISSION]</P>

Heterologous Expression of Rhizopus Oryzae CYP509C12 Gene in Rhizopus Nigricans Enhances Reactive Oxygen Species Production and 11α-Hydroxylation Rate of 16α, 17-Epoxyprogesterone

( Chaohui Shen ),( Xiyang Gao ),( Tao Li ),( Jun Zhang ),( Yuqian Gao ),( Liyou Qiu ),( Guang Zhang ) 한국균학회 2019 Mycobiology Vol.47 No.3

The 11a-hydroxylation of 16a, 17-epoxyprogesterone (EP) catalyzed by Rhizopus nigricans is crucial for the steroid industry. However, lower conversion rate of the biohydroxylation restricts its potential industrial application. The 11a-steroid hydroxylase CYP509C12 from R. oryzae were reported to play a crucial role in the 11a-hydroxylation in recombinant fission yeast. In the present study, the CYP509C12 of R. oryzae (RoCYP) was introduced into R. nigricans using the liposome-mediated mycelial transformation. Heterologous expression of RoCYP resulted in increased fungal growth and improved intracellular reactive oxygen species content in R. nigricans. The H₂O₂ levels in RoCYP transformants were approximately 2-folder that of the R. nigricans wild type (RnWT) strain, with the superoxide dismutase activities increased approximately 45% and catalase activities decreased approximately 68%. Furthermore, the 11a-hydroxylation rates of EP in RoCYP transformants (C4, C6 and C9) were 39.7%, 38.3% and 38.7%, which were 12.1%, 8.2% and 9.4% higher than the rate of the RnWT strain, respectively. This paper investigated the effect of heterologous expression of RoCYP in R. nigricans, providing an effective genetic method to construct the engineered strains for steroid industry.

Heterologous Expression of Rhizopus Oryzae CYP509C12 Gene in Rhizopus Nigricans Enhances Reactive Oxygen Species Production and 11α-Hydroxylation Rate of 16α, 17-Epoxyprogesterone

Shen, Chaohui,Gao, Xiyang,Li, Tao,Zhang, Jun,Gao, Yuqian,Qiu, Liyou,Zhang, Guang The Korean Society of Mycology 2019 Mycobiology Vol.47 No.3

The $11{\alpha}$-hydroxylation of $16{\alpha}$, 17-epoxyprogesterone (EP) catalyzed by Rhizopus nigricans is crucial for the steroid industry. However, lower conversion rate of the biohydroxylation restricts its potential industrial application. The $11{\alpha}$-steroid hydroxylase CYP509C12 from R. oryzae were reported to play a crucial role in the $11{\alpha}$-hydroxylation in recombinant fission yeast. In the present study, the CYP509C12 of R. oryzae (RoCYP) was introduced into R. nigricans using the liposome-mediated mycelial transformation. Heterologous expression of RoCYP resulted in increased fungal growth and improved intracellular reactive oxygen species content in R. nigricans. The $H_2O_2$ levels in RoCYP transformants were approximately 2-folder that of the R. nigricans wild type (RnWT) strain, with the superoxide dismutase activities increased approximately 45% and catalase activities decreased approximately 68%. Furthermore, the $11{\alpha}$-hydroxylation rates of EP in RoCYP transformants (C4, C6 and C9) were 39.7%, 38.3% and 38.7%, which were 12.1%, 8.2% and 9.4% higher than the rate of the RnWT strain, respectively. This paper investigated the effect of heterologous expression of RoCYP in R. nigricans, providing an effective genetic method to construct the engineered strains for steroid industry.