基于HHT-RDT算法的高拱坝泄流结构工作模态识别方法

根据高拱坝泄流结构自身的工作特点,为准确辨识环境激励下的结构模态参数特征,提出了一种基于改进的HHT-RDT算法的高拱坝泄流结构工作模态识别方法。以某高拱坝原型振动响应测试资料为基础,利用改进的小波阈值-EMD算法对原始信号进行降噪预处理,滤除干扰噪声的同时保留有效特征信息;采用HHT-RDT算法识别高拱坝泄流结构的工作模态参数,运用带通滤波对振动响应信号的EMD过程进行控制得到结构的各阶模态分量,利用RDT法提取各阶模态分量的自由衰减信息,识别出高拱坝泄流结构系统的固有频率及阻尼比。工程实例表明,该方法避免了复杂系统定阶过程,有效提高结构振动响应工作模态识别精度,为辨识高拱坝泄流结构的工作模态参数提供捷径。     

高能同步辐射光源逐束团束流位置测量电子学研制

基于高能同步辐射光源（HEPS）储存环，研制了一套逐束团束流位置测量（BPM）电子学系统，电子学的硬件部分由模拟信号采集板卡和数字信号处理板卡组成，软件部分由底层固件和顶层应用软件组成。系统的采样频率为500 MHz，带宽为1 GHz，对来自储存环BPM探头的4路模拟信号进行数字化，得到束团幅度数据，利用ZYNQ芯片计算出每个束团在真空管道中的位置。逐束团BPM电子学在实验室的测试结果为：输入信号峰峰值小于1.8 V时ADC通道非线性度小于1%，无杂散动态范围约60 dB，灵敏度系数取8.26 mm时位置分辨率优于10 μm，测试结果满足HEPS逐束团BPM的需求。     

丁烷氧化反应器装置数据分析与优化

基于丁烷氧化反应器的实际装置数据，经预处理后，采用主成分分析进行数据挖掘。结果表明，可利用该方法来筛选及判断异常数据点，从而可用于反应器状态的实时诊断和预警，同时对反应器输入和输出参数之间的相关性进行分析，理解和把握参数之间的变化特征，发现丁烷转化率与反应器出口的CO/CO2比值呈负相关，体现主反应和副反应的选择性问题，从而可用于指导反应器操作优化等。     

质子交换膜燃料电池电化学阻抗谱弛豫时间分布研究

电化学阻抗谱技术能够获取燃料电池不同频率阻抗，但对阻抗的构成缺乏进一步解析，难以直接构建精准的等效电路模型进行阻抗拟合分析，而弛豫时间分布（Distribution of relaxation time，DRT）方法不需要定义特定的等效电路模型，即可解析燃料电池不同时间常数的极化过程。针对实验室用质子交换膜燃料电池，在不同运行条件下对其进行阻抗谱测量，并通过Kramers-Kronig关系验证所记录阻抗数据的质量。基于DRT分析方法，系统地解释阻抗谱中各频段阻抗对应的物理或化学意义。研究表明，该电池的电化学阻抗谱主要由3个不同时间常数频段的极化阻抗构成，通过与运行条件相关性的系统分析，确定低频段阻抗为氧气在多孔介质中的传输阻碍，中频段阻抗为与氧还原反应有关的电荷传递阻碍，中高频段阻抗为阴极催化剂层中的质子传输阻碍。为进一步确定DRT分析结果的合理性，采用等效电路模型拟合测量的阻抗数据，辨识的电阻元件参数变化趋势与DRT分析结果一致。     

基于VMD与时间序列分析的滚动轴承故障特征提取方法

为了在非线性、非平稳的滚动轴承故障振动信号中有效提取出敏感的故障特征,提出了基于变分模态分解(VMD)与时间序列分析相结合的特征提取方法。首先通过VMD将原始信号分解为不同预设尺度的本征模态分量(IMF),对各个IMF分量建立时间序列预测模型,通过叠加重构得到最终的预测模型,比较评价指标确定最优参数的选取。最后,通过仿真信号与滚动轴承实际故障数据分析,并与经验模式分解(EMD)进行对比,结果表明该方法能够有效的提取到故障特征频率。     

热轧带钢边部翘皮缺陷成因分析

为了探明低碳钢在带钢轧制过程中出现边部翘皮缺陷的形成原因,取样分析了翘皮缺陷形貌及夹杂物成分,并采用ø750 mm×550 mm高刚度二辊热轧机组进行实验室模拟轧制分析翘皮缺陷演化过程。通过建立不同轧制方案,探明了热轧带钢翘皮缺陷形成于精轧道次,缺陷的产生与坯表面质量和边部原始凝固组织无关,轧材在轧制过程中由于边部不均匀变形形成侧面凹陷,凹陷在后续轧制中被轧制压缩闭合,并翻转到表面成为翘皮缺陷。最后,工业生产试验表明,倒角铸坯可提高轧材边部在轧制过程中的温度和均匀性,抑制轧材边部不均匀变形,有效降低翘皮缺陷的发生率。     

一种基于双重ddPCR的肉制品中牛源性成分的定量分析方法

将低价肉类原料掺入高价肉制品是一种典型的肉类掺假方式，为准确鉴别牛肉及牛肉制品的真伪，建立一种基于双重微滴式数字聚合酶链式反应（droplet digital polymerase chain reaction，ddPCR）的牛源性成分定量分析方法。通过对14 种动物的Beta-actin单拷贝基因序列进行分析，设计牛源性特异性引物、探针与动物源性成分通用引物、探针并建立双重ddPCR体系，推导出牛源性成分质量与其特异性扩增拷贝数之间的计算公式，对牛源性成分进行定量检测该方法得到牛源性成分质量M牛（mg）与其特异性扩增拷贝数浓度C牛（copies/μL）之间的计算公式为M牛=0.033C牛＋2.37，对已知牛肉质量的混合肉样品与不同部位的牛肉样品进行检测，结果显示牛肉定量检测值与实际质量基本一致。同时拷贝数相对含量可辅助判断肉制品中是否存在非牛源性的其他动物源性成分掺假。对市售样品的检测发现，存在目标肉样含量不达标以及不同程度的动物源性成分等掺假现象，说明该检测方法可为牛肉制品掺假量化判定和混合源性产品分级鉴定提供技术支撑。     

Effects of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria on growth and reactive oxygen metabolism of tomato fruits under low saline conditions

Land salinization is a major form of land degradation, which is not conducive to the growth and quality of fruits and vegetables. Plant salt tolerance can be enhanced by arbuscular mycorrhizal fungi (AMF) or plant growth-promoting rhizobacteria (PGPR). This study examined the effects of inoculation with PGPR singly or in combination with AMF, on the growth and quality of tomato fruits under low saline conditions. Tomatoes were cultivated in a greenhouse with sterilized soil, inoculated with PGPR, AMF, or co-inoculated with PGPR and AMF, and NaCl solution (1%) was added to the soil. The results indicated that AMF + PGPR decreased the roots and shoot biomass accumulation, and increased the number and fresh biomass in tomato fruits to a certain extent compared with non-inoculated plants. PGPR and AMF mediated the level of reactive oxygen and lipid peroxidation, the accumulation of antioxidants, and the activity of antioxidant enzymes, including proanthocyanidins, flavonoids, ascorbic acid, superoxide dismutase, peroxidase, and total antioxidant capacity. Furthermore, PGPR, AMF, and PGPR + AMF improved the overall osmotic adjustments and accumulation of soluble sugars and soluble proteins. Therefore, the AMF-Funneliformis mosseae and PGPR-Bacillus subtilis can potentially alleviate the adverse effects of salt stress and be applied as a biofertilizer in agricultural practice.     

An integrated bioinformatics analysis and experimental study identified key biomarkers CD300A or CXCL1, pathways and immune infiltration in diabetic nephropathy mice

Diabetic nephropathy (DN) is a common microvascular complication that easily leads to end-stage renal disease. It is important to explore the key biomarkers and molecular mechanisms relevant to diabetic nephropathy (DN). We used highthroughput RNA sequencing to obtain the genes related to DN glomerular tissues and healthy glomerular tissues of mice. Then we used LIMMA to analyze differentially expressed genes (DEGs) between DN and non-diabetic glomerular samples. And we performed KEGG, gene ontology functional (GO) enrichment, and gene set enrichment analysis to reveal the signaling pathway of the disease. The CIBERSORT algorithm based on support vector machine was used to determine the immune infiltration score. Random forest algorithm and Cytoscape obtained hub genes. Finally, we applied co-staining, immunohistochemical staining, RT-qPCR and western blotting to validate the protein and mRNA expression of both hub genes. We obtained 913 DEGs mainly related to inflammatory factors and immunity. GSEA results showed that differential genes were mainly enriched in IL-17 signaling pathway, lipid and atherosclerosis, rheumatoid arthritis, TNF signaling pathway, neutrophil extracellular trap formation, Staphylococcus aureus infection and other pathways. The intersection of the random forest algorithm and Cytoscape revealed both hub genes of CD300A and CXCL1. Experiments have shown that the both key genes of CD300A and CXCL1 shown increased expression in glomerular podocytes, and are related to the inflammation of diabetic nephropathy. And immunohistochemical staining and RT-qPCR further confirmed that the protein and mRNA expression level of CD300A or CXCL1 in glomeruli tissue in DN mice were increased. The expression levels of CD300A and CXCL1 increased significantly under HG (high glucose) stimulation, further confirming that diabetes can lead to increased levels of CD300A and CXCL1 at the cellular level. Through bioinformatics analysis, machine learning algorithms, and experimental research, CD300A and CXCL1 are confirmed as both potential biomarkers in diabetic nephropathy. And we further revealed the main pathways of differential genes and the differentially distributed immune infiltrating cells in diabetic nephropathy.