Copper-coated aluminum wires exhibit good electrical conductivity, high thermal conductivity, low contact resistance of copper and low density, and provide economic advantages over aluminum. However, there are some pr...Copper-coated aluminum wires exhibit good electrical conductivity, high thermal conductivity, low contact resistance of copper and low density, and provide economic advantages over aluminum. However, there are some problems in the manufacring processes of hot-dip copper-coated aluminum wires, such as the difficulties in controlling coating process. In this work, the hot-dip copper-coating method of aluminum wires was investigated for producing copper-coated aluminum wire composites. The interface microstructure between the aluminum wire and the copper coating layer was analyzed by scanning electron microscopy （SEM） and energy-dispersive X-ray spec- trometry （EDS）. Five different fluxing agents were tested. Experimental results show that appropriate conditions for the hot-dip process are determined as the liquid copper temperature of 1085℃ and the treatment time less than 1 s. A success in hot-dip copper-coated aluminum wires is achieved by hot-dipping a low-melting-point metal into a high-melting-point metal liquid, which is significant for the further devel- opment and application of copper-coated aluminum wire composites.展开更多
Kerfless technology is a promising alternative for reducing cost and providing flexible thin crystals in silicon-based semiconductors. In this work we propose a protruded seed substrate technology to prepare flexible ...Kerfless technology is a promising alternative for reducing cost and providing flexible thin crystals in silicon-based semiconductors. In this work we propose a protruded seed substrate technology to prepare flexible monocrystalline Si thin film economically. Grooved seed substrate is fabricated by using SiNx thin film as a mask for the wet-etching and thermal oxidation process. After the SiNx layer on the wedged strip is removed by hot phosphoric acid, the pre-defined structured substrate is achieved with the top of the strip serving as the seed site where there is no oxide layer. And a preferred growth of epitaxial Si on the substrate is performed by introducing an intermittent feed method for silicon source gas. The technique in this paper obviously enhances the mechanical stability of the seed structure and the growth behavior on the seed sites, compared with our previous techniques, so this technique promises to be used in the industrial fabrication of flexible Si-based devices.展开更多
The thermal radiation properties of pyrolytic carbon(PyC)protective coatings for monocrystalline silicon furnace prepared by different processes were tested.The changes of normal emissivity of carbon materials caused ...The thermal radiation properties of pyrolytic carbon(PyC)protective coatings for monocrystalline silicon furnace prepared by different processes were tested.The changes of normal emissivity of carbon materials caused by PyC protective coatings were discussed,and the influence of phase structure and surface appearance on the thermal radiation properties was investigated.The results show that the thermal radiation properties of PyC protective coatings with the wave band of 5-25μm are better than C/C substrate,further,normal spectral emissivity of CVD PyC coating remains basically at 0.85-0.90,and the normal total emissivity can reach0.89,which shows high thermal radiation performance.For resin PyC coating and CVD PyC coating,the degree of graphitization are 44.53%and 16.28%respectively,and the R value of Raman spectrum are 0.964and 1.384 respectively.Relatively disorder graphite structure of the latter causes various vibration modes,and the spectral emissivity is better,so the thermal radiation property of CVD PyC coating is excellent.A lot of spherical particles exists on the surface of the CVD PyC coating,and the more interface and spacing of particles reduce the number of particles per unit volume.Therefore,the scattering of thermal radiation is strongly strengthened,and the spectral emissivity is higher.展开更多
Erythropoietic protoporphyria（EPP）, an autosomal dominant disease, is caused by partial deficiency of ferrochelatase（FECH）, which catalyzes the terminal step of heme biosynthesis because of loss-of-function mutati...Erythropoietic protoporphyria（EPP）, an autosomal dominant disease, is caused by partial deficiency of ferrochelatase（FECH）, which catalyzes the terminal step of heme biosynthesis because of loss-of-function mutations in the FECH gene. To date, only a few cases have been described in Asia. In this study, we describe the clinical features of two Chinese patients with EPP, with diagnosis confirmed by the increase of free protoporphyrin in erythrocytes, detection of plasma fluorescence peak at 630–634 nm, and analysis of FECH gene mutations. Using gene scanning, we identified a small deletion in the FECH gene（c.973 delA） in one proband（patient A） and a pathogenic FECH mutation（c.1232 GT） in the other（patient B） and also observed some nucleotide variations（c.798 CG, c.921 AG, IVS1-23 CT, IVS3＋23 AG, IVS9＋35 CT, and IVS3-48 TC） in these patients. The family pedigree of patient A was then established by characterization of the genotype of the patient＇s relatives. We also analyzed the potential perniciousness of the missense mutation with bioinformatic software, Polyphen and Sift. In summary, Chinese EPP patients have similar manifestations to those of Caucasians, and identification of the Chinese FECH gene mutations expands the FECH genotypic spectrum and may contribute to genetic counseling.展开更多
基金the financial support from the Natural Science Foundation of Hunan Province, China (No. 2021JJ20062)Innovation Driven Project of Central South University, China (No. 2020CX038)+3 种基金High-tech Industry Science and Technology Innovation Leading Project of Hunan Province, China (No. 2022GK4058)Landmark Innovation Demonstration Project of Hunan Province, China (No. 2019XK2304)the National Key R&D Program of China (No. 2019YFC1907301)China Scholarship Council (No. 202006375018)。
基金financially supported by the Research Fund for the Doctoral Program of Higher Education of China(No.20100006120020)
文摘Copper-coated aluminum wires exhibit good electrical conductivity, high thermal conductivity, low contact resistance of copper and low density, and provide economic advantages over aluminum. However, there are some problems in the manufacring processes of hot-dip copper-coated aluminum wires, such as the difficulties in controlling coating process. In this work, the hot-dip copper-coating method of aluminum wires was investigated for producing copper-coated aluminum wire composites. The interface microstructure between the aluminum wire and the copper coating layer was analyzed by scanning electron microscopy （SEM） and energy-dispersive X-ray spec- trometry （EDS）. Five different fluxing agents were tested. Experimental results show that appropriate conditions for the hot-dip process are determined as the liquid copper temperature of 1085℃ and the treatment time less than 1 s. A success in hot-dip copper-coated aluminum wires is achieved by hot-dipping a low-melting-point metal into a high-melting-point metal liquid, which is significant for the further devel- opment and application of copper-coated aluminum wire composites.
基金Project supported by the National Natural Science Foundation of China(Grant No.11374313)the Young Scientists Fund of the National Nature Science Foundation of China(Grant No.11504392)
文摘Kerfless technology is a promising alternative for reducing cost and providing flexible thin crystals in silicon-based semiconductors. In this work we propose a protruded seed substrate technology to prepare flexible monocrystalline Si thin film economically. Grooved seed substrate is fabricated by using SiNx thin film as a mask for the wet-etching and thermal oxidation process. After the SiNx layer on the wedged strip is removed by hot phosphoric acid, the pre-defined structured substrate is achieved with the top of the strip serving as the seed site where there is no oxide layer. And a preferred growth of epitaxial Si on the substrate is performed by introducing an intermittent feed method for silicon source gas. The technique in this paper obviously enhances the mechanical stability of the seed structure and the growth behavior on the seed sites, compared with our previous techniques, so this technique promises to be used in the industrial fabrication of flexible Si-based devices.
基金Sponsored by the National High Technology Research and Development Program of China(863 Program)(Grant No.2009AA035301)the ChinaPostdoctoral Science Foundation(Grant No.2012M511544)
文摘The thermal radiation properties of pyrolytic carbon(PyC)protective coatings for monocrystalline silicon furnace prepared by different processes were tested.The changes of normal emissivity of carbon materials caused by PyC protective coatings were discussed,and the influence of phase structure and surface appearance on the thermal radiation properties was investigated.The results show that the thermal radiation properties of PyC protective coatings with the wave band of 5-25μm are better than C/C substrate,further,normal spectral emissivity of CVD PyC coating remains basically at 0.85-0.90,and the normal total emissivity can reach0.89,which shows high thermal radiation performance.For resin PyC coating and CVD PyC coating,the degree of graphitization are 44.53%and 16.28%respectively,and the R value of Raman spectrum are 0.964and 1.384 respectively.Relatively disorder graphite structure of the latter causes various vibration modes,and the spectral emissivity is better,so the thermal radiation property of CVD PyC coating is excellent.A lot of spherical particles exists on the surface of the CVD PyC coating,and the more interface and spacing of particles reduce the number of particles per unit volume.Therefore,the scattering of thermal radiation is strongly strengthened,and the spectral emissivity is higher.
基金supported by the National Basic Research Project(973)of China(No.2012CB934000)the National Distinguished Youth Scholar Grant of China(No.31325010)
文摘Erythropoietic protoporphyria（EPP）, an autosomal dominant disease, is caused by partial deficiency of ferrochelatase（FECH）, which catalyzes the terminal step of heme biosynthesis because of loss-of-function mutations in the FECH gene. To date, only a few cases have been described in Asia. In this study, we describe the clinical features of two Chinese patients with EPP, with diagnosis confirmed by the increase of free protoporphyrin in erythrocytes, detection of plasma fluorescence peak at 630–634 nm, and analysis of FECH gene mutations. Using gene scanning, we identified a small deletion in the FECH gene（c.973 delA） in one proband（patient A） and a pathogenic FECH mutation（c.1232 GT） in the other（patient B） and also observed some nucleotide variations（c.798 CG, c.921 AG, IVS1-23 CT, IVS3＋23 AG, IVS9＋35 CT, and IVS3-48 TC） in these patients. The family pedigree of patient A was then established by characterization of the genotype of the patient＇s relatives. We also analyzed the potential perniciousness of the missense mutation with bioinformatic software, Polyphen and Sift. In summary, Chinese EPP patients have similar manifestations to those of Caucasians, and identification of the Chinese FECH gene mutations expands the FECH genotypic spectrum and may contribute to genetic counseling.
