A new technique, powder compact foaming process for the production of aluminumfoams has been studied in this article. According to this method, the aluminum pow-der is mixed with a powder foaming agent (TiH_2). Subseq...A new technique, powder compact foaming process for the production of aluminumfoams has been studied in this article. According to this method, the aluminum pow-der is mixed with a powder foaming agent (TiH_2). Subsequent to mixing, the powderblend is hot compacted to obtain a dense semi--finished product. Upon heating to tem-peratures within the range of the melting point, the foaming agent decomposes to evolvegas and the semi--finished product expands into a porous cellular aluminum. Foamingprocess is the key in this method. Based on experiments, the foaming characteris-tics were mainly analyzed and discussed. Experiments show that the aluminum--foamwith closed pores and a uniform cell structure of high porosity can be obtained usingthis method by adjusting the foaming parameters: the content of foaming agent andfoaming temperature.展开更多
We report experimental realization of a quantum version of Maxwell＇s demon using solid state spins where the information acquiring and feedback operations by the demon are achieved through conditional quantum gates.A...We report experimental realization of a quantum version of Maxwell＇s demon using solid state spins where the information acquiring and feedback operations by the demon are achieved through conditional quantum gates.A unique feature of this implementation is that the demon can start in a quantum superposition state or in an entangled state with an ancilla observer. Through quantum state tomography, we measure the entropy in the system, demon, and the ancilla, showing the influence of coherence and entanglement on the result. A quantum implementation of Maxwell＇s demon adds more controllability to this paradoxical thermal machine and may find applications in quantum thermodynamics involving microscopic systems.展开更多
Amniotic fluid stem cells(AFSC) are noncontroversial and abundant potentially transplantable cells. They are derived from fetal and amniotic sources and show osteogenic, neuronal, and adipogenic differentiation in cul...Amniotic fluid stem cells(AFSC) are noncontroversial and abundant potentially transplantable cells. They are derived from fetal and amniotic sources and show osteogenic, neuronal, and adipogenic differentiation in culture. Clinical material must be expanded in culture and sorted if clinical use is desired. Cellular senescence and replicative potential for AFSC cultures has had limited study, with scant data on gene expression over time. We report changes in samples from 17 patients over multiple passages form 10 to 81 population doublings. Longevity was unrelated to telomere length in these cells. It was related to upregulation of TWIST1, which is highly expressed in stem cells, and downregulation of genes associated with apoptosis.展开更多
文摘A new technique, powder compact foaming process for the production of aluminumfoams has been studied in this article. According to this method, the aluminum pow-der is mixed with a powder foaming agent (TiH_2). Subsequent to mixing, the powderblend is hot compacted to obtain a dense semi--finished product. Upon heating to tem-peratures within the range of the melting point, the foaming agent decomposes to evolvegas and the semi--finished product expands into a porous cellular aluminum. Foamingprocess is the key in this method. Based on experiments, the foaming characteris-tics were mainly analyzed and discussed. Experiments show that the aluminum--foamwith closed pores and a uniform cell structure of high porosity can be obtained usingthis method by adjusting the foaming parameters: the content of foaming agent andfoaming temperature.
基金Supported by the Ministry of Education of Chinathe National Key Research and Development Program of China under Grant No 2016YFA0301902
文摘We report experimental realization of a quantum version of Maxwell＇s demon using solid state spins where the information acquiring and feedback operations by the demon are achieved through conditional quantum gates.A unique feature of this implementation is that the demon can start in a quantum superposition state or in an entangled state with an ancilla observer. Through quantum state tomography, we measure the entropy in the system, demon, and the ancilla, showing the influence of coherence and entanglement on the result. A quantum implementation of Maxwell＇s demon adds more controllability to this paradoxical thermal machine and may find applications in quantum thermodynamics involving microscopic systems.
文摘Amniotic fluid stem cells(AFSC) are noncontroversial and abundant potentially transplantable cells. They are derived from fetal and amniotic sources and show osteogenic, neuronal, and adipogenic differentiation in culture. Clinical material must be expanded in culture and sorted if clinical use is desired. Cellular senescence and replicative potential for AFSC cultures has had limited study, with scant data on gene expression over time. We report changes in samples from 17 patients over multiple passages form 10 to 81 population doublings. Longevity was unrelated to telomere length in these cells. It was related to upregulation of TWIST1, which is highly expressed in stem cells, and downregulation of genes associated with apoptosis.
