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        검색결과 104

        41.
        2010.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A porous nickel-tin nano-dendritic electrode, for use as the anode in a rechargeable lithium battery, has been prepared by using an electrochemical deposition process. The adjustment of the complexing agent content in the deposition bath enabled the nickel-tin alloys to have specific stoichiometries while the amount of acid, as a dynamic template for micro-porous structure, was limited to a certain amount to prevent its undesirable side reaction with the complexing agent. The ratios of nickel to tin in the electro-deposits were nearly identical to the ratios of nickel ion to tin ion in the deposition bath; the particle changed from spherical to dendritic shape according to the tin content in the deposits. The nickel to tin ratio and the dendritic structure were quite uniform throughout the thickness of the deposits. The resulting nickel-tin alloy was reversibly lithiated and delithiated as an anode in rechargeable lithium battery. Furthermore, the resulting anode showed much more stable cycling performance up to 50 cycles, as compared to that resulting from dense electro-deposit with the same atomic composition and from tin electrodeposit with a similar porous structure. From the results, it is expected that highly-porous nickel-tin alloys presented in this work could provide a promising option for the high performance anode materials for rechargeable lithium batteries.
        4,000원
        42.
        2010.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Tin oxide thin films were prepared on borosilicate glass by rf reactive sputtering at different deposition powers, process pressures and substrate temperatures. The ratio of oxygen/argon gas flow was fixed as 10 sccm / 60 sccm in this study. The structural, electrical and optical properties were examined by the design of experiment to evaluate the optimized processing conditions. The Taguchi method was used in this study. The films were characterized by X-ray diffraction, UV-Vis spectrometer, Hall effect measurements and atomic force microscope. Tin oxide thin films exhibited three types of crystal structures, namely, amorphous, SnO and SnO2. In the case of amorphous thin films the optical band gap was widely spread from 2.30 to 3.36 eV and showed n-type conductivity. While the SnO thin films had an optical band gap of 2.24-2.49 eV and revealed p-type conductivity, the SnO2 thin films showed an optical band gap of 3.33-3.63 eV and n-type conductivity. Among the three process parameters, the plasma power had the most impact on changing the structural, electrical and optical properties of the tin oxide thin films. It was also found that the grain size of the tin oxide thin films was dependent on the substrate temperature. However, the substrate temperature has very little effect on electrical and optical properties.
        4,000원
        43.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ti(C,N) solid solutions in hot-pressed Ti() (x=0.0, 0.3, 0.5, 0.7, 1.0) and 40TiC-40TiN-20Ni (in wt.%) cermet were characterized in this study. For hot-pressed Ti(C,N)s, the lattice parameters and hardness values of Ti(C,N) were determined by using XRD (X-Ray Diffraction) and nanoindentation. The properties of hot-pressed Ti(C,N) samples changed linearly with their carbon or nitrogen contents. For the TiC-TiN-Ni cermet, the hardness of the hard phase and binder phase were determined by nanoindentation in conjunction with microstructural observation. The measured hardness values were GPa for the binder phase and GPa for the hard phase, which was close to the hardness of hot-pressed Ti().
        4,000원
        44.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objectives of this study were the development of a synthesis technique for highly active nanosized ITO powder and the understanding of the reaction mechanisms of the ITO precursors. The precipitation and agglomeration phenomena in ITO and precursors are very sensitive to reaction temperature, pH, and coexisting ion species. Excessive ion and ions had a negative effect an synthesizing highly active powders. However, with a relevant stabilizing treatment the shape and size of ITO and precursors could be controlled and high density sintered products of ITO were obtained. By applying the reprecipitation process (or stabilization technique), highly active ITO and powders were synthesized. Sintering these powders at for 5 hours produced 97% dense ITO bodies.
        4,000원
        45.
        2008.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present the structural, optical, and electrical properties of amorphous silicon suboxide (a-SiOx) films grown on indium tin oxide glass substrates with a radio frequency magnetron technique from a polycrystalline silicon oxide target using ambient Ar. For different substrate-target distances (d = 8 cm and 10 cm), the deposition temperature effects were systematically studied. For d = 8cm, oxygen content in a-SiOx decreased with dissociation of oxygen onto the silicon oxide matrix; temperature increased due to enlargement of kinetic energy. For d = 10 cm, however, the oxygen content had a minimum between 150˚ and 200˚. Using simple optical measurements, we can predict a preferred orientation of liquid crystal molecules on a-SiOx thin film. At higher oxygen content (x > 1.6), liquid crystal molecules on an inorganic liquid crystal alignment layer of a-SiOx showed homogeneous alignment; however, in the lower case (x< 1.6), liquid crystals showed homeotropic alignment.
        4,000원
        46.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        방오도료로 많이 쓰이던 유기주석화합물은 일반생물에게 미치는 독성이 매우 강하고 또한 내분비계 장애물질임이 밝혀지면서 이를 대체할 화합물들이 개발되고 있다. 그 가운데 본 연구에서는 Sea-Nine 211(4,5-dichlore-2-n-octyl-3(2H) isothiazolone)을 사용하여 이 화합물이 해양생물 특히 저서생물인 패류에게 얼마나 영향을 미치는지를 살펴보았다. 이를 위해 강원도 북부 해역에 주로 서식하는 북방대합(Pseudocardium
        4,000원
        47.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        방오도료로 많이 쓰인 유기주석화합물은 일반생물에게 미치는 독성이 매우 강하고 또한 내분비계 장애물질임이 밝혀지면서 이를 대체할 화합물들의 개발이 요구되고 있다. 그 가운데 이런 목적으로 만들어진 화합물인 Sea-Nine 211을 사용하여 이것이 해양생물 특히 저서생물인 패류에게 얼마나 영향을 미치는지를 살펴보고자 북방대합(P. sachalinensis)에게 강제 주사하여 생존율과 중장선의 미크로좀 중 I상 약물대사효소의 변화를 4일째가지 조사하였으며,
        4,000원
        48.
        2008.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The structural and electrical properties of amorphous BaSm2Ti4O12 (BSmT) films on a TiN/SiO2/Si substrate deposited using a RF magnetron sputtering method were investigated. The deposition of BSmT films was carried out at 300˚C in a mixed oxygen and argon (O2 : Ar = 1 : 4) atmosphere with a total pressure of 8.0 mTorr. In particular, a 45 nm-thick amorphous BSmT film exhibited a high capacitance density and low dissipation factor of 7.60 fF/μm2 and 1.3%, respectively, with a dielectric constant of 38 at 100 kHz. Its capacitance showed very little change, even in GHz ranges from 1.0 GHz to 6.0 GHz. The quality factor of the BSmT film was as high as 67 at 6 GHz. The leakage current density of the BSmT film was also very low, at approximately 5.11 nA/cm2 at 2 V; its conduction mechanism was explained by the the Poole-Frenkel emission. The quadratic voltage coefficient of capacitance of the BSmT film was approximately 698 ppm/V2, which is higher than the required value (<100 ppm/V2) for RF application. This could be reduced by improving the process condition. The temperature coefficient of capacitance of the film was low at nearly 296 ppm/˚C at 100 kHz. Therefore, amorphous BSmT grown on a TiN substrate is a viable candidate material for a metal-insulator-metal capacitor.
        4,000원
        51.
        2007.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        3,000원
        52.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ti 안경 태 의 nm 부분과 temple 부분을 분리 한 후, temple 부분을 시 료로 사용하 였다. 실험에 사용한 장비는 아크 이온플레이팅 장비이며, 이 장비를 이용하여 TiN과 TiC 이온도금을 하였다. Ti temple의 성분과 TiN, TiN 도금층과 TiC 도금층의 과 밀착성 시험을 행하였다. 그 결과, TiN temple은 Al을 첨가한 알파형 티탄테 temple이었으며, TiN 이온도금 층은 XPS data로부터 TiN으로, Ti와 결합을 잘하는 Oxygen이나 Carbon과의 결합 이 없다는 것을 알 수 있었다. 염수분무시험에서는 10 일이 경과 후에도 “이상없음”으 로 결과가 나왔으며, 이온도금층의 두께는 약 l.9 ]lm 이었다. 밀착성 시험에서 180。굽 혔을 때 도금층의 박리가 육안으로도 없었으며, 색상은 골드색에 가까운 색상이었다. TiC 이온도금층은 주로 TiC로 이루어져 있으며 N과 0가 약간 섞어있는 형태이었 다. 이온도금층의 두께는 약 l.6 jlm로 TíN 도금층보다 약간 작게 나왔으며, 염수분무 시험과 밀착성시험에서도 TiN 도금층과 같이 “이상없음”으로 결과가 나왔으며, 밀착 성 시험에서 도금층의 박리가 육안으로도 없었으며, 색상은 흑색이었다.
        4,000원
        53.
        2006.09 구독 인증기관 무료, 개인회원 유료
        Particulate reinforced titanium composites were produced by PM rout. Differents volumetric percentages of TiN reinforcements were used, 5,10,15 vol%. Samples were uniaxial pressed and vacuum sintered at differents temperatures between . Density, porosity, shrinkage, mechanical properties and microstructure were studied. Elastic properties and strength resistance were analysed by flexural strength and tension tests, and after the test, fractured samples were analysed too, obtaining a correlation between the fracture, interparticulated or intraparticulated, and the reinforcement addition.. Hardness and microhardness test were applied too, in order to complete the study about mechanical properties. In order to study wear resistance pin-on-disc test were used. In addition, the temperature influence, the reactivity between matrix and reinforcement, and the microstructures developed were observed by optical and electron microscopy.
        3,000원
        54.
        2006.04 구독 인증기관·개인회원 무료
        Development of recycling method at cemented carbide scraps was researched. Some properties of recycled cemented carbides were investigated. Recycled WC fine powder suffered the surface oxidation. Therefore it was necessary to be done by reduction treatment at 1073K-3.6ks under hydrogen atmosphere. When sintering condition at 1673K-3.6ks was treated under vacuum condition, it gained the deflective strength of about 90%, and gained hardness and sintering density about same value compared with commercial alloys. As a result, it was able to recycle only by 7 processes.
        55.
        2006.04 구독 인증기관·개인회원 무료
        Magnetron sputtered TiN, (Ti, Al)N and TiN/(Ti, Al)N multilayer coatings grown on cemented carbide substrates have been characterized by using electron probe microanalysis (EPMA), X-ray diffraction (XRD), scanning electron spectroscopy (SEM), nanoindentation, scratcher and cutting tests. Results show that TiN coating is bell mouth columnar structures, (Ti, Al)N coating is straight columnar structures and the modulation structure has been formed in the TiN/(Ti, Al)N multilayer coating. TiN/(Ti, Al)N multilayer coating exhibited higher hardness, better adhesion with substrate and excellent cutting performance compared with TiN and (Ti, Al)N coating.
        57.
        2006.04 구독 인증기관·개인회원 무료
        Tin oxide nanoparticles (n-SnO and ) were synthesized by the inert gas condensation (IGC) method under dynamic gas flow of oxygen and argon at various conditions. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) method were used to analysis the size, shape and crystal structure of the produced powders. The synthesized particles were mostly amorphous and their size increased with increasing the partial pressure of oxygen in the processing chamber. The particles also became broader in size when higher oxygen pressures were applied. Low temperature annealing at in air resulted to crystallization of the amorphous n-SnO particles to .
        59.
        2005.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nanostructured and composite powders have been prepared by mechanochemical reaction from mixtures of Ti, BN, and powders. The raw materials have reacted to form a uniform mixture of TiN, and or depending on the amount of used in the starting mixtures, and the reaction proceeded through so-called mechanically activated self-sustaining reaction (MSR). Fine TiN and crystallites less than a few tens of nanometer were homogeneously dispersed in the amorphous or matrix after milling for 12 hours. These amorphous matrices became crystalline phases after annealing at high temperatures as expected, but the original microstructure did not change significantly
        4,000원
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