http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Guocai (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Case Study: Slope Stability Assessment Considering 3D Nonlinear Shear Strength
Kai Liu,Guocai Wang,Peng Yuan,Huijian Zhang 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.1
In this paper, factor of safety (FOS) considering three-dimensional (3D) and nonlinear shear strength of geomaterials is formulated based on the modified spatial mobilized plane (MSMP) model. The MSMP model has the desirable features of considering 3D strength and the nonlinear shear behavior of soils, compared with the widely used Mohr-Coulomb (M-C) model. The MSMP model is developed from the spatial mobilized plane model by relating the internal friction angle to the mean effective stress within the framework of critical state soil mechanics. Based on the developed MSMP model and the geometric relationships in the mobilized effective normal-shear stress plane, the nonlinear 3D FOS is defined as the ratio of mobilized shear strength to shear stress. The developed nonlinear 3D FOS is applied to slope parametric and case studies. The parametric studies show significant differences between the nonlinear 3D FOS by the MSMP model and the traditional linear two-dimensional (2D) FOS by the M-C model. The case study shows that the MSMP model and nonlinear 3D FOS can better capture the developed failure slope zone than the M-C model and linear 2D FOS.
-
Zhenfeng Liu,Honglong Xing,Lei Wang,Dexin Tan,Ying Gan,Xiaoli Ji,Guocai Xu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.8
In this study, Zn-doped Fe3O4 nanoparticles were successfully synthesized by a facile solvothermal method in the presence of sodium dodecyl sulfate (SDS). The morphology, magnetic properties and electromagnetic wave absorbing properties of these materials were characterized. Results showed that Zn2+ played a significant role in the formation of Zn-doped Fe3O4. With the protection of SDS, highly dispersed Fe3O4 nanoparticles were obtained. The nanoparticle size decreased after Zn2+ doping, and the dispersity deteriorated with increasing Zn2+ doping concentration. Zndoped Fe3O4 exhibited excellent electromagnetic wave absorbing property, which resulted in magnetic loss and dielectric loss at an appropriate doping concentration. The minimum reflection loss (RL) was approximately -27.2 dB at 16.9 GHz. As the coating layer thickness increased to 4.0 mm, the bandwidth was approximately 5.0 GHz corresponding to RL below -10 dB, which nearly covered the entire S band (2–4 GHz) and C band (4–8 GHz). The peak frequency of RL and the number of peaks matched the quarter-wave thickness criteria. It was believed that the Zndoped Fe3O4 could be a potential electromagnetic wave absorbing material in S and C bands.
-
Synthesis and Excellent Microwave Absorption Properties of ZnO/Fe3O4/MWCNTs Composites
Lei Wang,Honglong Xing,Zhenfeng Liu,Ziyao Shen,Xiang Sun,Guocai Xu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.12
ZnO nanocrystals were introduced into Fe3O4/MWCNTs composites to improve the impedance matching and electromagnetic (EM) wave attenuation of the system. The as-synthesized ZnO/ Fe3O4/MWCNTs composites were characterized by X-ray diffraction, vibrating sample magnetometer, field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy. SEM and TEM images showed that Fe3O4 microspheres 100–200 nm in size connected MWCNTs. Analysis of EM parameters revealed that the impedance matching of the ZnO/Fe3O4/MWCNTs composites was considerably improved after ZnO nanocrystals were introduced. The ZnO/Fe3O4/MWCNTs composites exhibited a highly efficient microwave absorption (MA) capacity within the tested frequency range of 2–18 GHz. The optimal reflection loss of EM waves was -38.2 dB at 6.08 GHz with an absorber thickness of 3.5 mm. The excellent MA properties of the composites could be attributed to the improved impedance matching, interfacial polarization, and combined effects of dielectric and magnetic losses.
-
Rheological Behavior and Electrical Properties of Graphene Oxide/Polyaniline Nanocomposites
Qing Yin,Ruiwen Shu,Honglong Xing,Dexin Tan,Ying Gan,Guocai Xu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.2
In this work, graphene oxide/polyaniline (GO/PANI) nanocomposites were synthesized by an in situ polymerization of aniline monomer in GO aqueous dispersions. The morphology and structure of GO/PANI were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra and Raman spectra. The effects of the concentration of GO/PANI and temperature on the rheological behavior of silicone oil dispersions of GO/PANI nanocomposites were investigated. The results showed that the steady state viscosity of GO/PANI dispersions remarkably increased with the addition of only little GO and the concentrated dispersions showed characteristic shear-thinning behavior. Significantly, a Newtonian-pseudoplastic transition with a critical exponent of 2.2 was observed in silicone oil dispersions of GO/PANI with the increase of nanocomposites concentration. The viscosity of GO/PANI dispersions apparently decreased with increasing temperature, while the temperature showed a certain effect on the thixotropic behavior of concentrated dispersions. In addition, the effect of the GO content on the electrical conductivity of GO/PANI nanocomposites was also explored. It was noted that the GO sheets are effective fillers for improving the rheological behavior and electrical conductivity of PANI matrix. Therefore, the study of rheological behavior and electric property of GO/PANI nanocomposites could shed light on the processing and application of GO/conductive polymer nanocomposites.
-
ScienceON
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
