超顺磁性氧化铁纳米粒子(super paramagnetic iron oxide,SPIO)由于其独特的性质,如低毒、生物相容性、强大的磁性,在生物成像、材料科学、环境科学等方面广泛应用。本文概述了SPIO的基本性质、物理化学特性、合成方法,以及在各领域方...超顺磁性氧化铁纳米粒子(super paramagnetic iron oxide,SPIO)由于其独特的性质,如低毒、生物相容性、强大的磁性,在生物成像、材料科学、环境科学等方面广泛应用。本文概述了SPIO的基本性质、物理化学特性、合成方法,以及在各领域方面的应用进展。研究表明SPIO应用前景广阔,将满足更多社会生活需求。展开更多
The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effect...The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effective rapid solidified method to produce the Si-Al alloy and the size of atomized Si-Al alloy powder is less than 50 μm. The rapid solidified Si-Al alloy powder were hot pressed at 550 ℃ with the pressure of 700 MPa to obtain the relative densities of 99.4%, 99.2% and 94.4% for 55%Si-Al, 70%Si-Al and 90%Si-Al alloys, respectively. The typical physical properties, such as the thermal conductivity, coefficient of thermal expansion (CTE) and electrical conductivity of rapid solidified Si-Al alloys are acceptable as a heat dissipation material for many semiconductor devices. The 55%Si-Al alloy changes greatly (CTE) with the increase of temperature but obtains a good thermal conductivity. The CTE of 90%Si-Al alloy matches with the silicon very well but its thermal conductivity value is less than 100 W/(m.K). Therefore, the 70%Si-Al alloy possesses the best comprehensive properties of CTE and thermal conductivity for using as the heat sink materials.展开更多
文摘超顺磁性氧化铁纳米粒子(super paramagnetic iron oxide,SPIO)由于其独特的性质,如低毒、生物相容性、强大的磁性,在生物成像、材料科学、环境科学等方面广泛应用。本文概述了SPIO的基本性质、物理化学特性、合成方法,以及在各领域方面的应用进展。研究表明SPIO应用前景广阔,将满足更多社会生活需求。
基金Project (2011) supported by the Hunan Nonferrous Research Funding of Hunan Nonferrous Metals Holding Group Co.,Ltd.,China
文摘The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effective rapid solidified method to produce the Si-Al alloy and the size of atomized Si-Al alloy powder is less than 50 μm. The rapid solidified Si-Al alloy powder were hot pressed at 550 ℃ with the pressure of 700 MPa to obtain the relative densities of 99.4%, 99.2% and 94.4% for 55%Si-Al, 70%Si-Al and 90%Si-Al alloys, respectively. The typical physical properties, such as the thermal conductivity, coefficient of thermal expansion (CTE) and electrical conductivity of rapid solidified Si-Al alloys are acceptable as a heat dissipation material for many semiconductor devices. The 55%Si-Al alloy changes greatly (CTE) with the increase of temperature but obtains a good thermal conductivity. The CTE of 90%Si-Al alloy matches with the silicon very well but its thermal conductivity value is less than 100 W/(m.K). Therefore, the 70%Si-Al alloy possesses the best comprehensive properties of CTE and thermal conductivity for using as the heat sink materials.