Diffraction behavior of an azo-dye-doped nematic liquid crystal without applied electric field

Hongyue Gao,Kaiyu Gu,Zhongxiang Zhou,Yongyuan Jiang,Dewei Gong 한국물리학회 2008 Current Applied Physics Vol.8 No.1

We investigate the dependence of the two-beam coupling diffraction efficiency on the experimental parameters, and hence achieve the optimum experimental conditions for holographic recording in planar Methyl Red-doped nematic liquid crystal film without external electric field. Under the optimum experimental conditions, the diffraction efficiency of a holographic grating is improved to 21.4%, and holographic image with long-term stability is stored in the film. These results provide an experimental basis for holographic data storage in this liquid crystal film We investigate the dependence of the two-beam coupling diffraction efficiency on the experimental parameters, and hence achieve the optimum experimental conditions for holographic recording in planar Methyl Red-doped nematic liquid crystal film without external electric field. Under the optimum experimental conditions, the diffraction efficiency of a holographic grating is improved to 21.4%, and holographic image with long-term stability is stored in the film. These results provide an experimental basis for holographic data storage in this liquid crystal film

Core@shell MOFs derived Co2P/CoP@NPGC as a highly-active bifunctional electrocatalyst for ORR/OER

Weijia Gong,Hongyu Zhang,Liuyang Zhou,Ya Yang,Jiashuo Wang,Heng Liang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

In this study, Co2P/CoP hybrid nanoparticles (NPs) imbedded on the surface of core–shell metal–organicframeworks (MOFs) derived three-dimensional N, P co-doped graphitized carbon (Co2P/CoP@NPGC) areprepared via direct pyrolysis of P-containing MOF precursors. P dopant dosage is tailored to adjust activesites and crystalline phases of Co2P/CoP@NPGC. The active Co2P and CoP NPs and the synergistic effectfrom the Co-Nx/C and Co-P/C active sites and porous NPGC make the dominant contributions to theORR/OER. For ORR, the half-wave potential of Co2P/CoP@NPGC-1 is 0.93 V, which is superior to that ofPt/C (E1/2 = 0.875 V). As for OER, Co2P/CoP@NPGC-1 displays a lower overpotential (ƞ = 340 mV) comparedto RuO2 (ƞ = 380 mV, at 10 mA cm2). The Co2P@CoOOH heterojunction guarantees intrinsic conductivity. Furthermore, doping with N and P can modify the surface electronic structure of catalyst to lower theenergy of oxygen adsorption and dissociation, which are beneficial to enhance the ORR and OER activity. Additionally, its bifunctional activity parameter (DE) for ORR and OER is only 0.64 V, which is lower thanthat of Pt/C and RuO2 (0.76 V). Therefore, this work proposes a new sight into constructing a competitivecore–shell MOFs derived electrocatalyst for ORR/OER.

Fabrication and piezoelectricity of 0–3 cement based composite with nano-PZT powder

Zongjin Li,Hongyu Gong,Yujun Zhang 한국물리학회 2009 Current Applied Physics Vol.9 No.3

Lead zirconate titanate (Pb(Zr0.52Ti0.48)O3) (PZT) nano-powder with a perovskite structure was fabricated using sol–gel process. The average crystallite diameter of the PZT powder is calculated to be 23.6 nm and the average agglomerate size is about 200 nm. The 0–3 cement based nano-PZT composites were obtained by pressing the mixture of white cement and the nano-PZT powders under a high pressure followed by steam curing. The properties of the nano-PZT/cement piezoelectric composites have been measured and compared to the PZT/cement composites incorporated with ground coarse PZT particles. The enhanced piezoelectricity of the nano-PZT/cement composites can be attributed to the good connectivity between the nano-PZT particles among the cement matrix. Lead zirconate titanate (Pb(Zr0.52Ti0.48)O3) (PZT) nano-powder with a perovskite structure was fabricated using sol–gel process. The average crystallite diameter of the PZT powder is calculated to be 23.6 nm and the average agglomerate size is about 200 nm. The 0–3 cement based nano-PZT composites were obtained by pressing the mixture of white cement and the nano-PZT powders under a high pressure followed by steam curing. The properties of the nano-PZT/cement piezoelectric composites have been measured and compared to the PZT/cement composites incorporated with ground coarse PZT particles. The enhanced piezoelectricity of the nano-PZT/cement composites can be attributed to the good connectivity between the nano-PZT particles among the cement matrix.

Fabrication and properties of reaction-bonded SiC prepared by gelcasting

Lifang Nie,Hongyu Gong,Tao Zhang,Yujun Zhang 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.1

The properties of green and reaction-bonded SiC (RBSC) samples prepared by a gelcasting technique are investigated in this paper. The results show that solid loading and monomer content of the suspension in the gelcasting process are the main factors that effect the density and shrinkage of the green bodies. A slurry with a solid loading of 58 vol% was solidified in situ to a green body with a linear shrinkage of 1.1% and flexural strength of 27 ± 2 MPa. SEM micrographs show that the SiC and C particles in the green body were closely compact by a connection of the polymer network. The maximum density and flexural strength of samples reaction sintered at 1700℃ in vacuum were 2.97 g/㎤ and 378 ± 12 MPa respectively. The properties of green and reaction-bonded SiC (RBSC) samples prepared by a gelcasting technique are investigated in this paper. The results show that solid loading and monomer content of the suspension in the gelcasting process are the main factors that effect the density and shrinkage of the green bodies. A slurry with a solid loading of 58 vol% was solidified in situ to a green body with a linear shrinkage of 1.1% and flexural strength of 27 ± 2 MPa. SEM micrographs show that the SiC and C particles in the green body were closely compact by a connection of the polymer network. The maximum density and flexural strength of samples reaction sintered at 1700℃ in vacuum were 2.97 g/㎤ and 378 ± 12 MPa respectively.

Amplification of transglutaminase 2 enhances tumor-promoting inflammation in gastric cancers

Cho Sung-Yup,오유미,Jeong Eui Man,박상희,Dakeun Lee,Xiaorui Wang,Qiqi Zeng,Hongyu Qin,Fang Hu,Hui Gong,Xi Liu,Guanjun Zhang,나득채,이지은,채지수,서윤석,공성호,Hyuk-Joon Lee,Jong-Il Kim,박한수,Chengsheng Zhang,양한광,Charles Lee 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Tumor-promoting inflammation is a hallmark of cancer and is highly associated with tumor progression, angiogenesis, and metastasis. Tumor-associated macrophages (TAMs) are major drivers of tumor-promoting inflammation, but due to the complexity of the tumor microenvironment, the detailed regulatory mechanisms are still under investigation. Here, we investigated a novel role for transglutaminase 2 (TGM2) in the development of tumor-promoting inflammation and recruitment of TAMs to gastric cancer (GC) tissues. When estimated by array comparative genomic hybridization and droplet digital PCR, the copy numbers of the TGM2 gene were amplified in 13.6% (14/103) of GC patients and positively associated with TGM2 expression. Gene set enrichment analysis of expression microarray data for GC samples with high or low TGM2 expression showed that increased TGM2 expression was associated with tumor-promoting inflammation in GC. In addition, the expression of TGM2 was correlated with the expression of markers for macrophages, neutrophils, blood vessels, and lymphatic vessels. Overexpression of TGM2 in GC cells augmented the IL-1β-induced secretion of macrophage-recruiting chemokines and NF-κB activation. TGM2 protein levels were associated with the expression levels of the macrophage marker CD163 in human GC tissue samples. Moreover, GC patients with high expression of TGM2 had a worse prognosis than those with low expression of TGM2. These results suggest TGM2 as a novel regulator of the tumor microenvironment of GC and provide a promising target for constraining tumor-promoting inflammation.