Dear Editor,Since 2024,the clade 2.3.4.4b highly pathogenic avian influenza(HPAI)H5N1 viruses have been identified in dairy cattle in the United States,raising global concerns about public health(Neumann and Kawaoka,2...Dear Editor,Since 2024,the clade 2.3.4.4b highly pathogenic avian influenza(HPAI)H5N1 viruses have been identified in dairy cattle in the United States,raising global concerns about public health(Neumann and Kawaoka,2024).As of December 18,2024,the U.S.Centers for Disease Control and Prevention(CDC)has reported over 61 confirmed cases of H5N1 infection in humans,predominantly associated with exposure to infected poultry or dairy cattle(U.S.Centers for Disease Control and Prevention,2024).Notably,the circulating 2.3.4.4b H5N1 clade has demonstrated continuous evolution in both wild and domestic birds globally,with expanding mammalian host tropism that now includes swine,cats,red foxes,harbor seals,and skunks(Peacock et al.,2024).These viruses have not only incurred substantial economic impacts but also posed dual threats to human health and ecological stability particularly during co-infections with other viruses(Abolnik,2024;Wang and Wang,2023).展开更多
为了提高金刚石-铜合金复合材料的界面粘结强度,本文用差热分析(DTA)、X 射线衍射分析、SEM 观察及磨削试验研究了金刚石表面的 Ti 镀层对金刚石-铜基合金复合材料界面结构及性能的影响。结果表明,在600～1200℃镀Ti 层与金刚石发生界...为了提高金刚石-铜合金复合材料的界面粘结强度,本文用差热分析(DTA)、X 射线衍射分析、SEM 观察及磨削试验研究了金刚石表面的 Ti 镀层对金刚石-铜基合金复合材料界面结构及性能的影响。结果表明,在600～1200℃镀Ti 层与金刚石发生界面反应,在金刚石表面外延生成岛状 TiC,从而实现了金刚石与铜基合金的冶金结合。镀 Ti 金刚石与铜合金的粘结强度可达8×10~7Pa。用镀 Ti金刚石制成的铜基合金磨块对花岗岩的磨削比与不镀钛金刚石相比提高30%。展开更多
本文用差热分析（DTA）,X 射线衍射分析,SEM 观察及磨削试验研究了镀 W 金刚石与铜合金结合剂界面成分、结构及结合性能。结果表明:在700～1250℃范围内,镀 W 层与金刚石发生界面反应,在金刚石表面外延生成岛状 WC 和 W<sub>2<...本文用差热分析（DTA）,X 射线衍射分析,SEM 观察及磨削试验研究了镀 W 金刚石与铜合金结合剂界面成分、结构及结合性能。结果表明:在700～1250℃范围内,镀 W 层与金刚石发生界面反应,在金刚石表面外延生成岛状 WC 和 W<sub>2</sub>C 从而实现了金刚石与 W 镀层间的冶金结合,即金刚石表面金属化。镀 W 金刚石与铜合金的粘结强度可达4×10<sup>7</sup>Pa。用镀钨金刚石制成的磨块磨削比、出刃高度得到提高,金刚石的脱落率大幅度下降。展开更多
文摘Dear Editor,Since 2024,the clade 2.3.4.4b highly pathogenic avian influenza(HPAI)H5N1 viruses have been identified in dairy cattle in the United States,raising global concerns about public health(Neumann and Kawaoka,2024).As of December 18,2024,the U.S.Centers for Disease Control and Prevention(CDC)has reported over 61 confirmed cases of H5N1 infection in humans,predominantly associated with exposure to infected poultry or dairy cattle(U.S.Centers for Disease Control and Prevention,2024).Notably,the circulating 2.3.4.4b H5N1 clade has demonstrated continuous evolution in both wild and domestic birds globally,with expanding mammalian host tropism that now includes swine,cats,red foxes,harbor seals,and skunks(Peacock et al.,2024).These viruses have not only incurred substantial economic impacts but also posed dual threats to human health and ecological stability particularly during co-infections with other viruses(Abolnik,2024;Wang and Wang,2023).
文摘为了提高金刚石-铜合金复合材料的界面粘结强度,本文用差热分析(DTA)、X 射线衍射分析、SEM 观察及磨削试验研究了金刚石表面的 Ti 镀层对金刚石-铜基合金复合材料界面结构及性能的影响。结果表明,在600～1200℃镀Ti 层与金刚石发生界面反应,在金刚石表面外延生成岛状 TiC,从而实现了金刚石与铜基合金的冶金结合。镀 Ti 金刚石与铜合金的粘结强度可达8×10~7Pa。用镀 Ti金刚石制成的铜基合金磨块对花岗岩的磨削比与不镀钛金刚石相比提高30%。
文摘本文用差热分析（DTA）,X 射线衍射分析,SEM 观察及磨削试验研究了镀 W 金刚石与铜合金结合剂界面成分、结构及结合性能。结果表明:在700～1250℃范围内,镀 W 层与金刚石发生界面反应,在金刚石表面外延生成岛状 WC 和 W<sub>2</sub>C 从而实现了金刚石与 W 镀层间的冶金结合,即金刚石表面金属化。镀 W 金刚石与铜合金的粘结强度可达4×10<sup>7</sup>Pa。用镀钨金刚石制成的磨块磨削比、出刃高度得到提高,金刚石的脱落率大幅度下降。
