改进加权融合算法与双谱技术在风电轴承故障诊断中的应用

针对风电回转支承转速低、不稳定、受载复杂等问题,并且其故障振动信号为低频信号,往往呈现非高斯、非线性特点。提出了基于改进加权融合算法与双谱技术相结合的数据融合诊断方案。首先提出了改进的加权融合算法对多传感器数据进行融合;然后采用双谱技术处理非高斯、非线性信号,提取出隐藏在融合信号中的非高斯特征。最终通过实验表明,运用该诊断方案提取出的特征频率与理论计算的故障特征频率相吻合,充分显示了其应用在回转支承故障诊断系统中的可行性。

探讨在胰腺脂肪沉积病情诊断中应用双能量能谱CT物质定量分析技术的价值

目的:探讨双能量能谱CT物质定量分析技术在胰腺脂肪沉积病情诊断中的应用价值。方法:选取2021年6月—2022年6月于广州市番禺区第二人民医院进行诊治的60例胰腺脂肪沉积患者为观察组,将37例同期在医院接受胰腺功能检查但是检查结果无异常的研究对象纳入对照组,两组均进行双能量能谱CT检查,比较对照组与观察组胰腺组织CT值、胰腺脂肪含量与水含量,对比观察组≥28 kg/m^(2)组、≥24~<28 kg/m2组及<24kg/m^(2)组患者胰腺CT值及胰腺脂肪含量与水含量。结果:观察组患者胰腺组织CT值显著低于对照组受检者(P<0.01)。观察组患者胰腺脂肪含量显著高于对照组受检者,胰腺水含量显著低于对照组(P<0.01)。BMI值越高则患者胰腺CT值越低,≥28kg/m^(2)组、≥24~<28 kg/m^(2)组及<24 kg/m^(2)组患者胰腺CT值差异均有统计学意义(P<0.05)。BMI值越高则胰腺脂肪含量越高,胰腺水含量越低,≥28 kg/m^(2)组、≥24~<28 kg/m^(2)组及<24 kg/m^(2)组患者胰腺脂肪含量与水含量差异均显著(P<0.01)。结论:双能量能谱CT物质定量分析技术能够对胰腺组织中的脂肪沉积情况进行定量、客观描述,有助于为临床准确诊断胰腺脂肪沉积提供影像学依据。

Mass Spectrometric Investigation of the Chemical Composition of Caramel Formed upon Heating of Disaccharides

Disaccharides are a very important group of carbohydrates, being main components of many daily food products. The heating of these biomolecule causes the formation of caramel, an extremely complex material. The dominant fraction of non-volatile compounds, responsible for both color and flavor of food products, has been studied on a few occasions. Herein, the composition of caramels obtained by heating of sucrose, lactose and maltose were studied using combined mass spectrometry techniques. High resolution electrospray mass spectrometry was applied followed by targeted multi-stage LC-tandem mass spectrometry （ESI-MSn） and MALDI-MS. Novel graphical interpretation strategies such as van Krevelen and Kendrick mass analysis have been applied to study the composition of caramels. Products of caramel include oligomerization, depolymerization, hydration and dehydration products. Oligomers with up to eight carbohydrate units and dehydrated oligomers losing up to eight water molecules have been identified.

Linear and Nonlinear Optical Properties of Novel Multi-branched Oligomers

We investigate the fluorene-vinylene unit dependent photo-physical properties of multi- branched truxene based oligomers （Tr-OFVn, n=1-4） employing steady-state absorption and emission spectroscopy, transient absorption spectroscopy, two-photon fluorescence, and z-scan technique. The results show that the increasing of fluorene-vinylene unit leads to a red-shift in the spectra of absorption and fluorescence, and shortens the excited state lifetime. Meanwhile, two-photon fluorescence efficiency and two-photon absorption cross section of truxene based oligolners gradually enhance in company with the extension of π- conjugated length. In addition, the values of two-photon absorption cross section modeled on the sum-over-state approach agree well with the experimental ones. The results indicate multi-branched truxene based oligomers bearing organic materials for two-photon applications.