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排序方式: 共有526条查询结果,搜索用时 15 毫秒
101.
Misun Sung Sung Sun Park Sung-Soo Kim Chan-Kyu Han Jung-Mu Hur 《Food science and biotechnology》2014,23(5):1615-1621
The antioxidant activities and hepatoprotective effects of Schizandra chinensis Baill. extracts (SCE) were evaluated. The contents of the active components schisandrin, schisandrin C, gomisin A, and gomisin N in SCE were 8.802±1.390, 1.011±0.203, 0.954±0.191, and 3.351±0.829 mg/g, respectively. The antioxidant activity of SCE was measured based on the DPPH free radical scavenging activity and the superoxide dismutase (SOD)-like activity. The IC50 values for the DPPH radical scavenging activity and SOD-like activity were 18.1 and 44.2mg/mL, respectively. The protective effect of SCE against alcohol-induced oxidative injury in HepG2 cells was investigated. Cells pretreated with SCE (100–400 μg/mL) showed an increased resistance to oxidative stress in a dose-dependent manner. Expressions of Bcl-2 and pro-caspase-3 proteins were induced by SCE in HepG2 cells. SCE can be useful for management of antioxidant and hepatoprotective effects. 相似文献
102.
Steam reforming (SR) of glycerol for the production of hydrogen was investigated over the nano-sized Ni-based catalysts. The Ni-based catalysts were prepared by solid phase crystallization and impregnation methods, and characterized by N2 physisorption, CO chemisorption, XRD, SEM, and TEM techniques. The Ni/gamma-Al2O3 catalyst showed higher conversion and H2 selectivity. However, it was slowly deactivated due to the carbon formation on the surface of catalyst and the sintering. It was found that the Ni based hydrotalcite-like catalyst (spc-Ni/MgAl) showed higher catalytic activity to prevent carbon formation than Ni/gamma-Al2O3 catalyst in the SR of glycerol. 相似文献
103.
Ahn JK Park KW Hur SG Kim CS Lee JY Yoon SG 《Journal of nanoscience and nanotechnology》2011,11(1):189-194
The feasibility of new InSbTe (IST) chalcogenide materials at the deposition temperatures of 225 and 250 degrees C using metalorganic chemical vapor deposition (MOCVD) for phase-change random access memory (PRAM) applications was investigated. Samples grown at 225 degrees C consisted of the main InTe phase, including a small amount of Sb. On the other hand, samples grown at 250 degrees C included the crystalline phases of InSb and InSbTe. MOCVD-IST materials are powerful candidates for highly-integrated PRAM applications. 相似文献
104.
Cheng-Kui Jiang Kyung-Ah Lee Cheon-Jei Kim Joo-Yeon Lee Sun-Jin Hur Si-Kyung Lee 《Food science and biotechnology》2013,22(6):1717-1724
The quality characteristics of cheonggukjang containing Phellinus linteus extracts (PLE) and its cytotoxicity in Hep-2 and SK-MS-cells were investigated. Cheonggukjang containing 0.3% PLE showed the highest protease activity (7th aging day). The reducing sugar content and the amylase activity of cheonggukjang supplemented with 0.3% PLE increased immediately on the 1st aging day, and decreased slightly until the 15th aging day. All samples showed an increase in the amino-type nitrogen content. The dominant volatile compound detected using chromatography-mass spectrophotometry was 2,5-dimethyl pyrazine with the highest peak area value of 17.36% observed in cheonggukjang containing 0.3% PLE (3rd aging day). Cheonggukjang containing 0.3% PLE exhibited the best taste and acceptability with the least unpleasant odor. Cheonggukjang supplemented with PLE had a higher antitumor activity against SK-MES-1 and Hep-2 cells than a control. Hep-2 cells treated with a 10 mg/mL extract of cheonggukjang containing 0.3% PLE showed the highest growth inhibition rate of 84.74%. 相似文献
105.
Süleyman Köytepe M. Hurşit Demirel Turgay Seçkin 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(5):1104-1112
A novel metallo-supramolecular polytopic ligand was synthesized from the attachment reaction involving an amino group-functionalized multi-wall carbon nanotube and 4-chloro-2,2′:6′,2″-terpyridine used for the preparation of metallo-supramolecular polymers with Co(II) or Ni(II) ions. Different colors were observed depending on either the ligands or the metal ions in this type of supramolecular assembly. The created supramolecular polymers were characterized by means of structure, morphology, and stimuli-responsive performance employing scanning electron microscopy, amperometric techniques, UV–Vis and Fourier transform infrared spectroscopy. UV–Vis spectroscopy and cyclic voltammetry studies confirmed that both the optical and electrochemical properties of metallo-supramolecular materials are affected by the substituent at the pyridine periphery. 相似文献
106.
Yong-Jun Lee Tae-Yang Shim Kwang-O Lee Man-Dae Hur Sung-Su Kang 《Journal of Mechanical Science and Technology》2013,27(8):2323-2329
A dual mass flywheel has positive effects on noise and vibration problems, but there are still difficulties securing sufficient component durability during the development process to increase the output. In this study, the fatigue life of a drive plate, a component in the power transmission path that is often fractured by cyclic loading, is evaluated in relation to heat treatment, and the effect of heat treatment on the fatigue life is studied. For this purpose, a fatigue test and rig test are conducted on both the raw material and heat-treated material of the drive plate. Based on the fatigue material properties obtained from the fatigue tests and the boundary conditions of the rig test, a fatigue analysis is conducted to predict the fatigue life. The heat-treated material has a fatigue life five times longer than the raw material in both the rig test and fatigue analysis. The fatigue life evaluation method is validated through a comparison of the life predicted by the fatigue analysis and the test results of the rig test. 相似文献
107.
Sang Ho Kang Shin Goo Hur Hee Woo Lee Tae Hyun Nam 《Metals and Materials International》2000,6(4):381-387
Ti-Ni and Ti-Ni-Cu alloy powders have been fabricated by ball milling after which their microstructures and transformation
behaviors were investigated by means of scanning electron microscopy, X-ray diffraction, energy dispersive X-ray analysis,
transmission electron microscopy and differential scanning calorimetry. The powders of as-milled Ti-Ni-Cu alloys whose Cu-content
is less than 5 at.% were mixtures of crystal and amorphous, whereas those alloy powders whose Cu-content is more than 10 at.%
were crystalline. The B19’ martensite is formed in the Ti-Ni-Cu alloy powders whose Cu-content is less than 10 at.%, whereas
the B19 and B19’ martensites coexist in those whose Cu-content is more than 10 at.%. The martensitic transformation range
became wider with increasing rotating speed, and so endothermic and exothermic peaks obtained from differential scanning calorimetry
were indiscernible. 相似文献
108.
Performances of combined adsorption and chemical precipitation were evaluated as one of the options for pretreatment or post-treatment
of a municipal solid waste (MSW) landfill leachate and leachate from an industrial solid waste landfill. The COD and color
removals of the leachate from a MSW landfill were 35% and 33% at an alum dose of 300 mg/L with preceding PAC (powdered activated
carbon) dose of 200 mg/L, respectively. For MSW leachate, the combined adsorption and coagulation process showed 2.3 times
higher COD removal at PAC dose of 200 mg/L and alum dose of 500 mg/L than the unit process of adsorption with poor settleability.
The COD removal was accomplished mainly by adsorption, while coagulation was a key mechanism of color removal. The COD and
color of the biologically treated leachate from an industrial solid waste landfill were removed up to 32% and 68%, respectively,
at addition of 490 mgAlum/L and 1,000 mgPAC/L in adsorption-coagulation process with pH control. Combined adsorption and coagulation
process with pH control showed better COD and color removal than the process without pH control. The color removal was influenced
greatly by pH control, while COD removal was not. No difference in removal efficiency was observed between adsorption-coagulation
and coagulation-adsorption. Maximum net increases in the COD and color removals by the adsorption-coagulation process were
40% and 46%, respectively, compared with the removals by sole chemical precipitation. The Freundlich isotherm exclusively
described the adsorption of leachate components on the PAC. Thus, a combined adsorption and coagulation process was considered
to be effective for pre-treatment or post-treatment of landfill leachate, and has distinct features of simple, flexible, stable
and reliable operation against fluctuation of leachate quality and flowrate. 相似文献
109.
Suk-Hun Lee Jae-Kyu Chun Jae-Jin Hur Jae-Seung Lee Gi-Hong Rue Young-Ho Bae Sung-Ho Hahm Yong-Hyun Lee Jung-Hee Lee 《Electron Device Letters, IEEE》2000,21(6):261-263
This is a first time report of a ruthenium oxide (RuO2) Schottky contact on GaN. RuO2 and Pt Schottky diodes were fabricated and their characteristics compared. When the RuO2 Schottky contact was annealed at 500°C for 30 min, the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the RuO2 were dramatically improved. The annealed RuO2 /GaN Schottky contact exhibited a reverse leakage current that was at least two or three orders lower in magnitude than that of the Pt/GaN contact along with a very large barrier height of 1.46 eV, which is the highest value ever reported for a GaN Schottky system 相似文献
110.
PLT thin films with a thickness of 600 nm were grown by pulsed laser deposition (PLD) using different laser wavelengths of 355, 532 and 1064 nm, respectively. We have systematically investigated the variation of grain sizes depending on the process condition. A two-step process to grow (Pb0.72La0.28)Ti0.93O3 (PLT) films was adopted and verified to be useful to enlarge the grain size of the film and to enhance leakage current characteristics. Structural and electrical properties including dielectric constant, ferroelectric characteristics, and leakage current of PLT thin films were shown to be strongly influenced by grain size. 相似文献