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GCr15钢轴承套圈内表面开裂原因
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作者 刘月云 杨娥 +1 位作者 周杨 彭先锦 《理化检验(物理分册)》 CAS 2023年第11期56-58,共3页
某GCr15钢轴承套圈经机加工后,发现其套圈内表面发生开裂。采用宏观观察、化学成分分析、扫描电镜及能谱分析等方法对开裂套圈进行分析。结果表明:在生产套圈过程中,穿孔顶头发生破碎,产生的异物颗粒嵌入基体,破坏了基体的连续性,最终... 某GCr15钢轴承套圈经机加工后,发现其套圈内表面发生开裂。采用宏观观察、化学成分分析、扫描电镜及能谱分析等方法对开裂套圈进行分析。结果表明:在生产套圈过程中,穿孔顶头发生破碎,产生的异物颗粒嵌入基体,破坏了基体的连续性,最终导致套圈内表面发生开裂。 展开更多
关键词 GCR15钢 轴承套圈 开裂 穿孔顶头 异物颗粒
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RNA interference-mediated inhibition of Hepatitis B Virus replication 被引量:3
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作者 TANGNi ZHANGBingqiang +4 位作者 yange PUDan GAOXiaolin Tong-ChuanHe HUANGAilong 《Chinese Science Bulletin》 SCIE EI CAS 2004年第14期1470-1475,共6页
Persistent and recurrent infection of hepatitis B virus (HBV) represents one of the most common and severe viral infections of humans, and has caused a formidable health problem in the affected countries. Currently us... Persistent and recurrent infection of hepatitis B virus (HBV) represents one of the most common and severe viral infections of humans, and has caused a formidable health problem in the affected countries. Currently used antiviral drugs have a very limited success on controlling HBV replication and infection. RNA interference (RNAi), a process by which double-stranded RNA (dsRNA) directs sequence-specific degradation of target mRNA in mammal-ian and plant cells, has recently been used to knockdown gene expression in various species. In this study, we sought to determine whether RNAi-mediated silencing of HBV viral gene expression could lead to the effective inhibition of HBV replication. We first developed RNAi vectors that expressed small interfering RNA (siRNA) and targeted the HBV core or surface gene sequence. Our results demonstrated that these specific siRNAs efficiently reduced the levels of corre-sponding viral RNAs and proteins, and thus suppressed viral replication. Treatment with siRNA gave the greatest reduc-tion in the levels of HBsAg (92%) and in HBeAg (85%) re-spectively in the cultured cell medium. Our findings further demonstrated that the RNAi-mediated antiviral effect was sequence-specific and dose-dependent. Therefore, our find-ings strongly suggest that RNAi-mediated silencing of HBV viral genes could effectively inhibit the replication of HBV, hence RNAi-based strategy should be further explored as a more efficacious antiviral therapy of HBV infection. 展开更多
关键词 抗病毒疗法 肝炎B病毒 RNA冲突 病毒复制 基因疗法
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高强度弹簧钢60Si2CrVAT拉伸试样异常断裂原因分析 被引量:1
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作者 杨娥 陈君 +3 位作者 张军 周杨 杨智 李波 《物理测试》 CAS 2018年第4期34-37,共4页
某公司生产的高强度弹簧钢60Si2Cr VAT圆棒材,出厂之前检测力学性能时发现部分试样抗拉强度及屈服强度满足标准要求,但断面收缩率及断后伸长率指标均明显低于标准要求。利用体视显微镜及扫描电子显微镜(SEM)对力学性能异常试样断裂原... 某公司生产的高强度弹簧钢60Si2Cr VAT圆棒材,出厂之前检测力学性能时发现部分试样抗拉强度及屈服强度满足标准要求,但断面收缩率及断后伸长率指标均明显低于标准要求。利用体视显微镜及扫描电子显微镜(SEM)对力学性能异常试样断裂原因进行了分析。结果表明,性能不合格试样属于异常断裂,试样制备过程中表面产生加工硬化、甚至出现微裂纹是引起拉伸试样异常断裂的主要原因。改善样坯热处理后的加工方式可消除此类异常断裂现象。 展开更多
关键词 高强度弹簧钢 异常断裂 加工硬化
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