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 : Guoguang Yao (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
Effects of V2O5 on sinterability and microwave dielectric properties of NaCa4V5O17 ceramics
Guoguang Yao,Yang Li,Jingjing Tan,Cuijin Pei,Yan Zhang,Jia Chen 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.3
The NaCa4V5O17 ceramics owing low sintering temperature had been prepared via conventional solid state reaction methodusing V2O5 as vanadium source. The sinterability, microwave dielectric characterisations and compatibility with Ag wereinvestigated. Pure phase NaCa4V5O17 with triclinic structure was confirmed by Rietveld refinement and Raman spectrum. Thepermittivity (εr) and quality factor (Qxf) values mainly depended on the relative density, whereas the temperature coefficientof resonant frequency (τf) value was closely connected with the tetrahedral distortion of V(1)O4. The NaCa4V5O17 ceramicssintered at 800 oС owned high densification and moderate microwave dielectric performances under 10.7 GHz: εr = 9.5, Q×f= 34,200 GHz, τf = -90.0 ppm/oС, but poor chemical compatibility with Ag paste.
-
Yao Li,Guoguang Cheng,Jinlong Lu,Hu Long 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.4
In this paper, in order to identify the formation mechanism of duplex (Ca,Mn)S inclusions in steel, based on the two heats ofcommercial Ca-treated resulfurized steel, the characteristics of duplex (Ca,Mn)S inclusions in bars, blooms and CaO-Al2O3oxides in molten steel were observed and analyzed. The results indicate that there are three types of duplex (Ca,Mn)S inclusionsin steel. The first type with over 20% Ca in (Ca,Mn)S is named as “Type-C”, the second with 4–20% Ca in (Ca,Mn)Sis named as “Type-MC” and the third with below 4% Ca in (Ca,Mn)S is named as “Type-M”. Their core oxides are mainlyCa-Mg–Al-O oxides. The aspect ratios of duplex (Ca,Mn)S inclusions in bars decrease as Ca content in (Ca,Mn)S increases. From Type-M to Type-C, CaO content in core oxides increases, and Ca content in wrapping (Ca,Mn)S increases. The shapeof duplex (Ca,Mn)S inclusions can be controlled through controlling CaO content in core oxides. During solidification,CaO-Al2O3 oxides become as heterogeneous nucleation cores of MnS inclusions, duplex (Ca,Mn)S inclusions forming inthis way, and Ca in wrapping (Ca,Mn)S come from CaO in core oxides. The higher CaO content in core oxides, the higherCa content in wrapping (Ca,Mn)S. Under the condition with specific Ca/S ratio in steel, to obtain more duplex (Ca,Mn)Sinclusions, numbers of Type-C should be decreased, and numbers of Type-MC and Type-M should be increased. To achievethis goal, the key is to obtain larger numbers of CaO-Al2O3 oxides with lower CaO and smaller sizes in molten steel.
-
Pengshen Wu,Cuijin Pei,Miao Chen,Xu Gao,Weihong Liu,Guoguang Yao,Jin Liu 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.6
By a reaction-sintering approach Li3Mg2SbO5F2 oxyfluorides ceramics were prepared. The sinterability, microstructure,phase transition along with microwave dielectric performances of present ceramics were researched. A gradual phase transitionfrom cubic to orthorhombic in Li3Mg2SbO5F2 ceramics sintered above 825 °C was identified by XRD refinement analysis. The microwave dielectric performances of present ceramics were closely correlated with its phase transition process andmicrostructure. Typically, optimal microwave dielectric performances (εr ~ 8.1, τf ~ –54.0 ppm/°C, Q × f ~ 68,500 GHz (under9.2 GHz)) were achieved for 825 °C-sintered Li3Mg2SbO5F2 ceramics. Moreover, a cylindrical dielectric resonator antennafabricated from Li3Mg2SbO5F2 ceramics exhibited a maximum return loss (S11) of –30.3 dB, a maximum gain of 5.3 dB andVSWR of 1.1 at the center frequency of 11.6 GHz, and impedance bandwidth of 300 MHz (at –10 dB), respectively.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
