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排序方式: 共有1534条查询结果,搜索用时 8 毫秒
91.
Jinseob Shin Kyomin Shin Hanna Lee Jeong‐Beom Nam Jae‐Eun Jung Jee‐Hyun Ryu Joo‐Hyun Han Kyung‐Do Suh Yong‐Jin Kim Jongwon Shim Junoh Kim Sang‐Hoon Han Kookheon Char Yeon Kyung Kim Jin Ho Chung Min Jung Lee Byeong Cheol Kang Jin‐Woong Kim 《Advanced materials (Deerfield Beach, Fla.)》2010,22(6):739-743
92.
A 30-nm-thick Ni layer was deposited on top of the nc-Si:H (hydrogenated nanocrystalline Si) films by rf-magnetron sputter,
and then heat-treatments were carried out at temperatures of 350–500∘C. Si nanocrystallites were formed in the Ni/nc-Si:H bilayer films during the post-deposition heat-treatments. The intensity
of the photoluminescence spectra of the post-deposition heat-treated films gradually increased at wavelengths of ∼420 as well
as ∼580 nm with raising the annealing temperature from 350 to 500∘C. It is highly likely that the increase of the photoluminescence intensity is caused by the increase in the total volume
of the nanocrystallites in the films. It was found that the nickel-induced crystallization processing enhanced the formation
of Si cystallites with the size of ∼2 and ∼5 nm in the films. 相似文献
93.
Biofilter in water and wastewater treatment 总被引:1,自引:0,他引:1
Durgananda Singh Chaudhary Saravanamuthu Vigneswaran Huu-Hao Ngo Wang Geun Shim Hee Moon 《Korean Journal of Chemical Engineering》2003,20(6):1054-1065
Biofilter is one of the most important separation processes that can be employed to remove organic pollutants from air, water,
and wastewater. Even though, it has been used over a century, it is still difficult to explain theoretically all the biological
processes occurring in a biofilter. In this paper, the fundamental of biological processes involved in the biofilter is critically
reviewed together with the mathematical modeling approach. The important operating and design parameters are discussed in
detail with the typical values used for different applications. The most important parameter which governs this process is
the biomass attached to the medium. The relative merits of different methods adopted in the measurement of the biomass are
discussed. The laboratory-and full-scale applications of the biofilter in water and wastewater treatment are also presented.
Their performances in terms of specific pollutant removal are highlighted. 相似文献
94.
Jae-Chul Lee Ho-In Lee Jae-Pyoung Ahn Jae-Hyeok Shim Zhongliang Shi 《Metallurgical and Materials Transactions A》2001,32(6):1541-1550
A methodology to control interfacial microstructures, while suppressing formation of Al4C3 in wrought Al alloy composites reinforced with SiC, was demonstrated. Thermodynamic calculations were carried out to elucidate
how one can select process parameters in terms of alloy composition and fabrication temperature to obtain intended interfaces.
Experimental verifications were conducted using scanning electron microscopy (SEM) and transmission electron microscopy (TEM)
to validate calculated results. The reaction mechanisms for forming various interfaces were identified both theoretically
and experimentally. Evaluations of the interfacial bonding strengths and interfacial stability at elevated temperatures were
also carried out for various interface types. 相似文献
95.
Kwangsoo No Dae-Shik Chung Jae-Myung Kim Hye-Young Kim Wonbaek Kim Gunchoo Shim 《Journal of Materials Science》1991,26(13):3593-3598
YBa2Cu3O
x
superconductor was synthesized using Y2BaCuO5, BaCuO2, and CuO powder mixture. Reaction temperatures were identified using differential thermal analysis (DTA) and thermogravimetry (TG) for syntheses of precursor powders and the powder mixtures. Appropriate reaction temperatures for Y2BaCuO5 and BaCuO2 precursor powders were 950 and 930°C, respectively. Two endothermic reactions involving melt formations were identified on the DTA and TG curves of the powder mixture, and the liquid increased the reactivity of the YBa2Cu3O
x
formation. Powder mixture samples were sintered at various temperatures ranging from 880 to 1000°C. Microstructural and X-ray powder diffraction studies showed YBa2Cu3O
x
and impurities to be formed in the samples sintered at various temperatures. The samples sintered at 990 and 1000°C showed dense microstructures. The critical temperature was 84 K for the sample sintered at 880°C and rose to 92 K as the sintering temperature increased. 相似文献
96.
Vilmos Galamb Sang Chul Shim Fazle Sibtain Howard Alper 《Israel journal of chemistry》1985,26(3):216-218
The intermediates mentioned in the title are probably involved in the hydrogenation of olefins and dienes; bidentate phosphine and arsine cobalt complexes are useful reagents for these reactions. 相似文献
97.
Jong Duk Lee Byung Chang Shim Hyung Soo Uh Byung-Gook Park 《Electron Device Letters, IEEE》1999,20(5):215-218
This letter reports the surface morphology and current-voltage (I-V) characteristics of single-crystal silicon (c-Si), polycrystalline silicon (poly-Si), and amorphous silicon (a-Si) field emitter arrays (FEAs). As-deposited a-Si film has a smoother surface than poly-Si film. The surface morphology of the a-Si remains smooth even after phosphorus doping and oxidation at 950°C to be improved in emission characteristics, i.e., smaller anode current deviation among arrays smaller gate current, and higher failure voltage than those of poly-Si FEAs. Such improved characteristics can be explained by the smooth surface morphology which is kept during doping and oxidation. The surface roughness and emission characteristics of a-Si FEAs are comparable to those of c-Si FEAs 相似文献
98.
Gyu Bo Kim Jae Young Shim Seung Wan Cho Young June Chang Chung Hwan Jeon 《Journal of Mechanical Science and Technology》2008,22(6):1154-1162
With environmental concerns over emitted particulate matters(PM) from combustion systems, various researches have been conducted
on reduction and measurement techniques of particulate matters. The LII analysis results from numerical models and experiments
in an ethylene/air laminar diffusion flame at elevated pressure up to 2.0 MPa with laser fluence 0.07 J/cm2, detection wavelength 400 nm were compared to validate a modified LII numerical model. The lifetime of the LII signal decreased
as the elevated pressure increased, so that LII decay time also decreased in both results. In the aspect of heat transfer
mechanism, it becomes earlier that dominant conduction starts. This shows that the results matched well under the pressure
conditions. It is concluded that the LII numerical model could be applied to decide particle size in TIRE-LII at the high-pressure
condition. 相似文献
99.
Lithium-ion polymer cells composed of a carbon anode and a LiCoO2 cathode are assembled with a gel polymer electrolyte cured by in-situ chemical cross-linking with novel cross-linking agents. The strong interfacial adhesion between the electrodes and the porous polyethylene membrane by the chemical cross-linking results in the stable capacity retention of the cell. However, a reduction in the ionic mobility in both the electrolyte and the electrodes adversely affects the high rate performance of the cell. These results imply that proper control of the cross-linking density in the cell is imperative for achieving good capacity retention and high rate performance of the cell. 相似文献
100.
Low-frequency noise measurements on individual single-walled carbon nanotube transistors exhibiting ambipolar characteristics have been carried out. With a polymer electrolyte as gate medium, low-frequency noise can be monitored in both p- and n-channel operation of the same nanotube under the same chemical environment. 1/ f noise in the p-channel of polymer electrolyte gated nanotube transistor is similar to that of back gate operation. However, most devices exhibit significantly larger noise amplitude in the n-channel operation that has a distinct dependence on the threshold voltage. A nonuniform energy distribution of carrier trapping/scattering sites is considered to explain these observations. 相似文献