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基于灰色关联分析的GH2132线材高精度切削参数优化 被引量:4
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作者 史丽晨 刘亚雄 +2 位作者 史炜椿 卢竹青 豆卫涛 《表面技术》 EI CAS CSCD 北大核心 2022年第11期373-384,共12页
目的通过无心车床车削去除GH2132线材的表面缺陷,分析无心车床加工参数对线材表面粗糙度、尺寸误差和表面显微硬度的响应关系,并建立GH2132线材表面灰色关联度多目标优化模型,确定可行工艺参数域。方法采用响应曲面中心复合设计,测量车... 目的通过无心车床车削去除GH2132线材的表面缺陷,分析无心车床加工参数对线材表面粗糙度、尺寸误差和表面显微硬度的响应关系,并建立GH2132线材表面灰色关联度多目标优化模型,确定可行工艺参数域。方法采用响应曲面中心复合设计,测量车削后GH2132线材的表面粗糙度、尺寸误差和表面显微硬度;利用响应曲面法(Response Surface Method,RSM)分别建立表面粗糙度、尺寸误差和表面显微硬度的单目标预测模型,确定单目标优化最优工艺参数组;基于灰色关联分析(Grey Correlation Analysis,GRA)理论,以表面粗糙度、尺寸误差和表面显微硬度为优化指标进行降维处理,构建车削工艺参数与灰色关联度的二阶回归预测模型;绘制车削工艺参数与灰色关联度值的等值线图,确定可行工艺参数域。结果对建立的表面粗糙度、尺寸误差和表面显微硬度的单目标预测模型进行方差分析,显著度均小于0.0001。得到了最小表面粗糙度工艺参数组,切削速度n=373.919 r/min,进给速度v_(f)=0.475 m/min。得到了最小尺寸误差工艺参数组,n=375.636 r/min,v_(f)=0.596 m/min。得到了最大表面显微硬度工艺参数组,n=337 r/min,v_(f)=0.903 m/min。对于灰色关联度多目标预测模型,误差范围为0.13%~9.4%,确定的可行工艺参数域对应的最小灰色关联度值为0.54437。结论基于灰色关联分析的多目标预测模型的准确度较高,主轴转速n对多目标的响应程度大于进给速度v_(f)。通过确定可行工艺参数域,为GH2132线材去除表面缺陷提供工程参考。 展开更多
关键词 表面缺陷 多目标优化 无心车床 灰色关联度 可行工艺参数域
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Pharmacodynamic Mechanism of Kuanxiong Aerosol for Vasodilation and Improvement of Myocardial Ischemia 被引量:4
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作者 lu Yan YANG Mei-ling +7 位作者 SHEN A-ling LIN Shan PENG Mei-zhong WANG Tian-yi lu zhu-qing WANG Yi-lian PENG Jun CHU Jian-feng 《Chinese Journal of Integrative Medicine》 SCIE CAS CSCD 2022年第4期319-329,共11页
Objective: To explore the effect of Kuanxiong Aerosol(KXA)on isoproterenol(ISO)-induced myocardial injury in rat models.Methods: Totally 24 rats were radomly divided into control,ISO,KXA low-dose and high-dose groups ... Objective: To explore the effect of Kuanxiong Aerosol(KXA)on isoproterenol(ISO)-induced myocardial injury in rat models.Methods: Totally 24 rats were radomly divided into control,ISO,KXA low-dose and high-dose groups according to the randomized block design method,and were administered by intragastric administration for 10 consecutive days,and on the 9th and 10th days,rats were injected with ISO for 2 consecutive days to construct an acute myocardial ischemia model to evaluate the improvement of myocardial ischemia by KXA.In addition,the diastolic effect of KXA on rat thoracic aorta and its regulation of ion channels were tested by in vitro vascular tension test.The influence of KXA on the expression of calcium-CaM-dependent protein kinase Ⅱ(CaMK Ⅱ)/extracellular regulated protein kinases(ERK)signaling pathway has also been tested.Results: KXA significantly reduced the ISO-induced increase in ST-segment,interventricular septal thickness,cardiac mass index and cardiac tissue pathological changes in rats.Moreover,the relaxation of isolated thoracic arterial rings that had been precontracted using norepinephrine(NE)or potassium chloride(KCl)was increased after KXA treatment in an endothelium-independent manner,and was attenuated by preincubation with verapamil,but not with tetraethylammonium chloride,4-aminopyridine,glibenclamide,or barium chloride.KXA pretreatment attenuated vasoconstriction induced by CaCl_(2)in Ca^(2+)-free solutions containing K^(+) or NE.In addition,KXA pretreatment inhibited accumulation of Ca^(2+)in A7r5 cells mediated by KCl and NE and significantly decreased p-CaMK Ⅱ and p-ERK levels.Conclusion: KXA may inhibit influx and release of calcium and activate the CaMK Ⅱ/ERK signaling pathway to produce vasodilatory effects,thereby improving myocardial injury. 展开更多
关键词 Kuanxiong Aerosol myocardial ischemia VASODILATION CA^(2+) CaMKⅡ/ERK pathway
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