In order to improve the accuracy of rolling bearing fault diagnosis when the motor is running under non-stationary conditions,an AC motor rolling bearing fault diagnosis method was proposed based on heterogeneous data...In order to improve the accuracy of rolling bearing fault diagnosis when the motor is running under non-stationary conditions,an AC motor rolling bearing fault diagnosis method was proposed based on heterogeneous data fusion of current and infrared images.Firstly,VMD was used to decompose the motor current signal and extract the low-frequency component of the bearing fault signal.On this basis,the current signal was transformed into a two-dimensional graph suitable for convolutional neural network,and the data set was classified by convolutional neural network and softmax classifier.Secondly,the infrared image was segmented and the fault features were extracted,so as to calculate the similarity with the infrared image of the fault bearing in the library,and further the sigmod classifier was used to classify the data.Finally,a decision-level fusion method was introduced to fuse the current signal with the infrared image signal diagnosis result according to the weight,and the motor bearing fault diagnosis result was obtained.Through experimental verification,the proposed fault diagnosis method could be used for the fault diagnosis of motor bearing outer ring under the condition of load variation,and the accuracy of fault diagnosis can reach 98.85%.展开更多
文摘探究由低聚果糖、低聚异麦芽糖、大豆肽粉以及沙棘粉组成的益生元复合制剂对小鼠肠道微生物及短链脂肪酸的作用效果。60只4周龄雄性BALB/c随机分为空白组,益生元复合制剂低、中、高剂量组以及大豆肽粉组,分别灌胃无菌水,1 g/kg体质量、2 g/kg体质量、6 g/kg体质量的益生元复合制剂以及1.15 g/kg体质量的大豆肽粉溶液28 d。采用平板计数法检测小鼠粪便中肠球菌、肠杆菌、乳杆菌、双歧杆菌和产气荚膜梭菌的数量,采用16S r DNA高通量测序分析肠道菌群的变化,采用气相色谱法检测粪便中乙酸、丙酸和丁酸的含量。灌胃大豆肽粉以及低剂量益生元复合制剂后,乳杆菌和双歧杆菌数量极显著提高(P<0.01),中、高剂量的益生元复合制剂也可以使双歧杆菌的数量大幅提高(P<0.01)。16S r DNA高通量测序结果显示,灌胃的大豆肽粉和益生元复合制剂分别可以使Prevotellaceae_UCG-001和Prevotellaceae_NK3B31_group的丰度提高(P<0.05),并且在高剂量组中致病菌Helicobacter的丰度明显降低(P<0.05)。短链脂肪酸方面,高剂量的益生元复合制剂可以使乙酸、丙酸和丁酸含量显著提高(P<0.05),另外大豆肽粉也可以显著提高乙酸含量(P<0.05)。综上所述,益生元复合制剂可以促进小鼠肠道内有益菌的繁殖,抑制致病菌的生长,提高乙酸、丙酸和丁酸的含量,对改善肠道微生态和促进机体健康有一定的帮助。单独使用大豆肽粉可以促进双歧杆菌和乳杆菌的繁殖并提高乙酸的含量,显示出良好的生物活性。
基金supported by National Natural Science Foundation of China(No.61903291)Shaanxi Province Key R&D Program(No.2022GY-134)。
文摘In order to improve the accuracy of rolling bearing fault diagnosis when the motor is running under non-stationary conditions,an AC motor rolling bearing fault diagnosis method was proposed based on heterogeneous data fusion of current and infrared images.Firstly,VMD was used to decompose the motor current signal and extract the low-frequency component of the bearing fault signal.On this basis,the current signal was transformed into a two-dimensional graph suitable for convolutional neural network,and the data set was classified by convolutional neural network and softmax classifier.Secondly,the infrared image was segmented and the fault features were extracted,so as to calculate the similarity with the infrared image of the fault bearing in the library,and further the sigmod classifier was used to classify the data.Finally,a decision-level fusion method was introduced to fuse the current signal with the infrared image signal diagnosis result according to the weight,and the motor bearing fault diagnosis result was obtained.Through experimental verification,the proposed fault diagnosis method could be used for the fault diagnosis of motor bearing outer ring under the condition of load variation,and the accuracy of fault diagnosis can reach 98.85%.
