검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 66

        21.
        2009.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electromagnetic wave absorption sheets were fabricated by mixing of nanocrystalline soft magnetic powder, charcoal powder and polymer based binder. The complex permittivity, complex permeability, and scattering parameter have been measured using a network analyzer in the frequency range of 10 MHz10 GHz. The results showed that complex permittivity of sheets was largely dependent on the frequency and the amount of charcoal powder : The permittivity was improved up to 100 MHz, however the value was decreased above 1 GHz. The power loss of electromagnetic wave absorption data showed almost the same tendency as the results of complex permittivity. However, the complex permeability was not largely affected by the frequency, and the values were decreased with the addition of charcoal powder. Based on the results, it can be summarized that the addition of charcoal powder was very effective to improve the EM wave absorption in the frequency range of 10 MHz1 GHz.
        4,000원
        22.
        2008.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fe based () amorphous powder were produced by a gas atomization process, and then ductile Cu powder fabricated by the electric explosion of wire(EEW) were mixed in the liquid (methanol) consecutively. The Fe-based amorphous - nanometallic Cu composite powders were compacted by a spark plasma sintering (SPS) processes. The nano-sized Cu powders of 200 produced by EEW in the methanol were mixed and well coated with the atomized Fe amorphous powders through the simple drying process on the hot plate. The relative density of the compacts obtained by the SPS showed over 98% and its hardness was also found to reach over 1100 Hv.
        4,000원
        23.
        2007.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The magnetic alloys of Cu-Fe () were prepared by a mechanical alloying method and their structural and magnetic behaviors were examined by X-ray diffraction and Mossbauer spectra. The magnetization curves did not distinctly show the saturation at 70 kOe for the concentrated alloys of . The Mossbauer spectrum of at room temperature shows one Lorentzian line of the paramagnetic phase, whereas the Mossbauer spectrum of consists of sextet Lorentzian line at room temperature and a centered doublet line. The Mossbauer spectra of measured in the temperature ranges from 13 to 295 K, implies that to consists of two magnetic phases. One superimposed sextet corresponds to the ferromagnetic iron in Cu and the other one indicates the superparamagnetic iron rich phase.
        3,000원
        24.
        2006.09 구독 인증기관·개인회원 무료
        Two atomized alloy powders were pre-compacted by cold and subsequently hot forged at temperatures ranging from 653K to 845K. The addition of Cu and Mg causes a decrease in the eutectic reaction temperature of Al-10Si-5Fe-1Zr alloy from 841K to 786K and results in a decrease of flow stress at the given forging temperature. TEM observation revealed that in addition to Al-Fe based intermetallics, Al2Cu and Al2CuMg intermetallics appeared. The volume fraction of intermetallic dispersoids increased by the addition of Cu and Mg. Compressive strength of the present alloys was closely related to the volume fraction of intermetallic dispersoids.
        25.
        2006.09 구독 인증기관·개인회원 무료
        Dimensional change of compact made from (Fe-Cu) prealloyed powder and copper powder compared to that of compact made from iron-copper elemental powder. The compact made from the prealloyed powder with a copper content of 7.18mass% which is nearly equal to its solution limit and copper powder showed only the large contraction in spite of penetration of liquid copper into grain boundary of the prealloyed powder. But the compact made from iron-copper elemental powder showed the large expansion in spite of same chemical composition with former case.
        26.
        2006.09 구독 인증기관·개인회원 무료
        The magnetic inductance of nanocrystalline Fe73Si16B7Nb3Cu1 and an amorphous FeSiB powder sheet has been investigated to identify RFID performance. The powder was mixed with binder and solvent and tape-casted to form films. Results show annealing significantly influenced on the inductance of the material. The surface oxidation of the particles was the main reason for the reduced inductance. The maximum inductance of Fe73Si16B7Nb3Cu1 alloy was about 88μH at 17.4 MHz, about 65% greater compared to the FeSiB alloy. The higher inductance in the nanocrystalline alloy indicates it may be used as a potential replacement of current RFID materials.
        27.
        2006.04 구독 인증기관·개인회원 무료
        Fe-4Ni-0.5Mo-1Cu powder was selected as raw material, pressed and sinter-hardened at for 30 min with rapid cooling. The density varies in the range of . Its fatigue properties have been tested in axial loading of alternating tensile/compressive stress at R=-1 with a servo-pulse pump. The fatigue endurance limit was measured to be 260 MPa. The microstructure showed more homogeneous bainite and martensite. Fractography displayed the fatigue cracks initiated from the pore areas near the surface. A non-typical ductile fatigue striation was found. More dimples occurred on fracture surface due to the plastic deformation, which can prohibit cracking propagation and improve its fatigue properties.
        30.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        미량요소 Fe, Mn, Cu 및 Zn의 systematic variation 시비가 orchardgrass 및 white clover의 생육, 개화, 수량, 양분 함량 등에 미치는 영향 등을 구명하였다. 다량요소 양분을 동일량 시비한 조건에서 Fe/Cu(시험군-1), Mn/Zn(시험군-2) 및 Fe+Cu/Mn+Zn(시험군-3) 시험에서는 각 시험군 처리별 총 시비량을 systematic variation 방법으로 0/100, 25/75, 50/50, 7
        4,300원
        31.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orchardgrass 및 white clover에서 미량요소 Fe, Mn, Cu 및 Zn의 systematic variation 시비가 목초의 생육, 개화, 수량, 양분 함량 등에 미치는 영향 등을 구명하였다. 다량요소 양분을 동일량 시비한 조건에서 Fe/Cu(시험군-1), Mn/ Zn(시험군-2) 및 Fe+Cu/Mn+Zn(시험군-3) 시험에서는 systematic variation 방법으로 각 시험군 처리별 총 시비량을 0/100, 25/75, 50
        4,000원
        32.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report the crystallization and magnetic properties of non-equilibrium alloy powders produced by rod-milling as well as by new chemical leaching. X-ray diffractometry, transmission electron microscopy, differential scanning calorimetry and vibrating sample magnetometry were used to characterize the as-milled and leached specimens. After 400 h or 500 h milling, only the broad peaks of nano bcc crystalline phases were detected in the XRD patterns. The crystallite size, the peak and the crystallization temperatures increased with increasing Fe. After being annealed at for 1 h for as-milled alloy powders, the peaks of bcc are observed. After being annealed at for 1 h for leached specimens, these non-equi-librium phases transformed into fcc Cu and phases for the x=0.25 specimen, and into bcc phases for both the x=0.50 and the x=0.75 specimens. The saturation magnetization decreased with increasing milling time for alloy powders. On cooling the leached specimens from ,\;the magnetization first sharply increase at about for x=0.25, x=0.50, and x=0.75 specimens, repectively.
        4,000원
        33.
        2004.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to investigate behavior of abnormal expansion of the iron-copper compacts, we compared the dilatometric curves of the compacts which mixed the copper powder to the iron powder with those of compacts which mixed the copper powder to the iron-copper alloy powder. The dilatometric curves were obtained below the sintering conditions, which heated up to 115 by a heating rate of 1/min, held for 60min at 115 and cooled down at a rate of 2/min to room temperature. The dilatometric curves of the compacts showed the different expansion behavior at temperatures above the copper melting point in spite of same chemical composition. All of the compacts of former case showed large expansion, but all of the compacts in latter case showed large contraction. The microstructures of sintered compacts also showed the different progress in alloying of the copper into the iron powder. Namely we could observe the segregation at alloy part of copper into iron powder in case of the sintered compacts, which mixed the copper powder to the iron powder, but could not observe the segregation in compacts which mixed the copper powder to the iron-copper alloy powder. But the penetration of liquid copper into the interstices between solid particles was occurred at both cases. Therefore, the showing of the different dimensional changes in the compacts in spite of same chemical composition is due to more the alloying of copper into iron powder than the penetration of liquid copper into the interstices between solid particles.
        4,000원
        34.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orchardgrass 및 white clover에서 미량요소 Fe, Mn, Cu 및 Zn의 systematic variation 시비가 목초의 생육, 개화, 수량 및 양분 함량 등에 미치는 영향 등을 구명하였다. 다량요소 양분을 동일량 시비한 조건에서 시험군-1(Fe/Cu), 시험군-2(Mn/Zn), 시험군-3(Fe+Cu/Mn+Zn)의 처리내용은 시험군별 처리양분의 총 시비량()을 systematic variation 방법으로 각각 0/100, 25/
        4,000원
        35.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orchardgrass 및 white clover에서 미량요소 Fe, Mn, Cu 및 Zn의 systematic variation 시비가 목초의 생육, 개화, 수량 및, 양분 함량 등에 미치는 영향 등을 구명하였다. 다량요소 양분을 동일 양 시비한 조건에서 Fe/Cu(시험군-1), Mn/Zn(시험군-2) 및 Fe+Cu/Mn+Zn(시험군-3)의 처리는 systematic variation 방법으로 시험군별 총 시비량을 각각 0/100, 25/75, 50/
        4,000원
        36.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orcharduass 및 white clover에서 미량요소 Fe, Mn, Cu, Zn의 systematic variations 시비가 목초의 생육, 재화, 수량, 양분 함량 등에 미치는 영향 등을 구명하였다. 다량요소 양분을 동일량 시비한 조건에서 시험군-1(Fe/Cu), 시험군-2(Mn/Zn), 시험군-3(Fe+Cu/Mn+Zn)의 처리내용은 시험군별 총 시비량을 systematic variation 방법으로 각각 0/100, 25/75, 50/50,
        4,000원
        37.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orcharduass 및 white clover의 단파 및 혼파재배조건에서 미량요소 Fe, Mn, Cu, Zn, Mo 및 B의 조합시비가 목초의 생육, 개화, 수양, 양분함량 및 식생구성비율 등에 미치는 영향을 구명하였다. 다양요소 양분을 동일량 시비한 조건에서 7 수준의 미량요소 조합시비는 ; 대조구, ; Fe, : Fe+Mn, ; Fe+Mn+Cu, ; Fe+Mn+Cu+Zn, : Fe+Mn+Cu+Zn+Mo 및 ; Fe + Mn +Cu+Zn+Mo + B
        4,300원
        39.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orchardgrass 및 white clover의 단파 및 혼파 재배조건에서 미량요소 Fe, Mn, Cu, Zn, Mo및 B의 조합시비가 목초의 생육, 개화, 수량, 양분 함량 및 식생구성비율 등에 미치는 영향을 구명하였다. 다량요소 양분을 동일 량 시비한 조건에서 7 수준의 미량요소 조합시비는 ;대구조, ; Fe, ; Fe+Mn, : Fe+Mn+Cu, ; Fe+Mn+Cu+Zn, ; Fe+Mn+Cu+Zn+Mo 및 ;Fe+Mn+Cu+Zn+Mo+B로 하였
        4,000원
        40.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orchardgrass 및 white clover의 단파 및 혼파 재배조건에서 미량요소 Fe, Mn, Cu, Zn, Mo및 B의 조합시비가 목초의 생육, 개화, 수량, 양분 함량 및 식생구성비율 등에 미치는 영향을 구명하였다. 다량요소 양분을 동일 량 시비한 조건에서 7 수준의 미량요소 조합시비는 ; 대조구, ; Fe, ; Fe+Mn, ; Fe+Mn+Cu, ; Fe+Mn+Cu+Zn, ; Fe+Mn+Cu+Zn+Mo 및 ; Fe+Mn+Cu+Zn+Mo+B로
        4,000원
        1 2 3 4