迁移因子分析在齿轮箱变工况故障诊断中的应用

针对变工况下齿轮箱监测数据重用性低,受复杂工况影响大和传统诊断方法难以进行准确检测和有效识别,为此提出迁移因子分析算法(transfer factor analysis,TFA)。该算法基于高斯潜在因子模型,通过将训练数据和测试数据投影到性能优越、分布间距最小的潜在空间寻求公共潜在因子进行迁移,有效减小训练样本和测试样本分布差异,为变工况下设备故障诊断提供了新思路。实验证明,该算法相比传统机器学习算法(主成分分析、核主成分分析、局部线性嵌入算法和因子分析)及迁移成分分析(transferred component analysis,TCA)算法,故障诊断正确率平均提高10%~20%,最高可达93.63%,因此该算法可用于变工况下齿轮箱故障诊断。     

Seasonal changes and muscle type effect on the nutritional quality of intramuscular fat in Mirandesa-PDO veal

The influence of slaughter season and muscle type on the detailed fatty acid composition, including conjugated linoleic acid isomers, and contents of total cholesterol and lipid-soluble antioxidant vitamins (α-tocopherol and β-carotene) in Mirandesa-PDO veal was assessed. Mirandesa purebred calves (n = 29) were raised in a traditional production semi-extensive system, slaughtered in late spring (June) or early autumn (October) and the longissimus lumborum and semitendinosus muscles were sampled for analysis. Although the lipid composition of PDO veal was only slightly affected by the slaughter season, it was markedly changed by the muscle type. However, PDO veal had values of pasture-fed cattle for lipid grass intake indicators, in both seasons and muscles. From a human health standpoint, intramuscular fat in Mirandesa-PDO veal has a high nutritional value throughout the year, with favorable ratios of n− 6/n− 3 and contents of n− 3 PUFA and α-tocopherol, as a result of the beneficial effects of grass feeding.     

基于信号时频分析理论识别时变模态参数的实验

为研究温度对结构模态参数的影响设计了一套温度可控的实验设备。在这套实验设备提供的可控温度环境中采集悬臂梁结构的加速度响应信号,利用基于信号时频分析的模态参数辨识算法处理实验数据,得到其时变模态参数,包括固有频率和振型,以此研究温度对其模态参数的影响。分析结果显示了基于信号时频分析的模态参数辨识算法在处理非平稳信号以得到结构的时变模态参数上的应用前景,更重要的是实验数据的分析结果较好地反映了温度对结构模态参数的影响,为热环境下结构振动特性分析提供了可靠而且有价值的分析方法和实验依据。     

Separation and identification of hen egg protein isoforms using SDS–PAGE and 2D gel electrophoresis with MALDI-TOF mass spectrometry

Knowledge of the chemical composition and physicochemical properties of native egg white and yolk is necessary to interpret the functional and biological properties attributed to specific egg components. To date, many of the proteins located in this complex biological fluid remain uncharacterised, if not unknown. High-resolution techniques for proteome analysis, including SDS–PAGE and 2-dimensional (2D) gel electrophoresis, combined with mass spectrometry, were employed to separate and identify several protein components in hen’s egg. An advanced and sensitive glycoprotein staining kit was used to detect the presence of glycosylated proteins in the egg samples. Numerous spots were revealed when a mixture of egg white and yolk was subjected to 2D gel electrophoresis. Several of the already known egg proteins were identified. Isoforms of ovalbumin and conalbumin were visualised. The presence of FLJ 10305 and Fatso proteins in the proteome of Gallus domesticus was also confirmed.     

Alternatives toward proton conductive anhydrous membranes for fuel cells: Heterocyclic protogenic solvents comprising polymer electrolytes

Fuel cells are gaining increasing attention as a clean and promising technology for energy conversion. One of the key benefits of fuel cells compared to other methods is the direct energy conversion that enables the achievement of high efficiency. The electrolyte membrane is the most essential parts of a fuel cell unit, and consequently has been the subject of considerable research and development. Among the various types of proton conducting electrolytes examined for fuel cell applications, polymer electrolyte membranes (PEMs) are regarded as viable candidates since they enable operation of the cells at desirably low temperatures. This review describes recent progress in the design and development of high performance proton conducting PEMs, including the analysis of the design requirements and strategies for development of advanced PEMs for operation in anhydrous conditions. Some of the most widely used types of azole heterocycles are introduced and compared, particularly in terms of their performance characteristics in polyacids containing different functional groups. In addition, the latest research studies and progress in the field of azole-containing and azole-functionalized electrolyte systems are discussed and reviewed.     

Optimization of Deodorization Design for Four Different Kinds of Vegetable Oil in Industrial Trial to Reduce Thermal Deterioration of Product

Trans fatty acids (TFA) have been shown to be associated with various health disorders. Due to thermal stress, one major source of dietary TFA is high-temperature deodorization of vegetable oils. In this study, precision minimal deodorization was proposed to obtain healthier “zero-TFA” vegetable oils (TFA ≤0.3%). By optimizing temperatures for different deodorizers, dual columns with dual temperatures (DCDT) deodorizers were proposed, transformed, and industrially implemented among dozens of plants. The deodorization temperatures were optimized and customized, respectively, for four kinds of vegetable oil (soybean oil and rapeseed oil: tray column 205 °C and packed column 225 °C, maize oil and sunflower seed oil: tray column 210 °C and packed column 230 °C). Industrial trials showed that all four kinds of oils can achieve “zero-TFA” by DCDT deodorization at the customized mild temperatures, and meanwhile oil physicochemical qualities and shelf-life stabilities were compared with corresponding conventional refining oils. The initial free fatty acid and color were a little higher than that of conventional refining oils, but no significant differences were shown in change trends of these physicochemical indexes during the shelf life, which indicated a good and stable oil quality of “zero-TFA” oils for future industrial productions and sales.     

Diet and plasma evaluation of the main isomers of conjugated linoleic acid and trans-fatty acids in a population sample from Mediterranean north-east Spain

The aim of the present study was to describe the dietary pattern of a representative sample of 516 adult participants (203 men and 313 women) from Catalonia, a Spanish Mediterranean region, to assess their current dietary and plasma levels of trans C18:1, the major trans-fatty acid (TFA), and cis-9, trans-11 CLA, and trans-10, cis-12 CLA, the two major conjugated linoleic acid (CLA) isomers, and to evaluate their correlation with several cardiovascular disease risk factors. The population was a random sample derived from the Catalan Nutrition Survey. Plasma levels of the CLA isomers were determined in a subsample of 100 volunteers. The Catalan diet seemed to maintain some traits of the ‘traditional’ Mediterranean diet, although other components were lost. The dietary intakes of saturated fatty acids (SFA), TFA, cis-9, trans-11 CLA, and trans-10, cis-12 CLA were 12.3%, 0.84% (2.0 g/d), 0.030% (71.5 mg/d), and 0.0015% (3.4 mg/d) of the energy intake, respectively. Trans C18:1 accounted for 0.19% of the total plasma fatty acids, while the sum of cis-9, trans-11and trans-10, cis-12 CLA isomers represented about 0.09% of the plasma fatty acids. Trans C18:1 isomers correlated significantly with the intake of French fries and pastries, while cis-9, trans-11 CLA significantly correlated with the intake of dairy products and ruminant meat. None of the cardiovascular disease risk factors were found to be associated with the plasma levels of TFA or CLA. The results of this study suggest that monounsaturated fatty acids (MUFA) are the main dietary fat source in the Catalan population, due to their regular olive oil consumption. Moreover, plasma levels of the main TFA and CLA suggest that the Catalan diet is not at present strongly influenced by the occidental dietary patterns. However, a reduction of the intake of SFA in the Catalan population should be recommended.     

Phenolic content and antioxidant capacity of Chinese raisins produced in Xinjiang Province

Raisins of 9 grape genotypes from Xinjiang Province were evaluated for phenolic composition and dietary antioxidant potential by using several assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, cupric reducing antioxidant power (CUPRAC), nitrite scavenging capacity (NTSC), potassium ferricyanide reducing power (PFRAP), and hydroxyl radical scavenging capacity (HRSC). Desert king had the highest content of total phenolics, total flavonoids, oligo proanthocyanidin, and total flavanols. Significance analysis demonstrated that Desert king had the highest antioxidant capacity in DPPH, CUPRAC, NTSC, and PFRAP. In HRSC, red manaizi showed the highest antioxidant capacity. 3,4-Dihydroxybenzoic acid was the predominant phenolic compound in the majority of raisin samples.     

Foaming properties of tryptic gliadin hydrolysate peptide fractions

A tryptic gliadin hydrolysate was separated into central domain (CD) or terminal domain (TD) related peptide fractions. Whereas the initial foam volume (FV) of CD peptide fractions remained constant as a function of pH, FV of TD peptide fractions increased from acidic to alkaline pH. Foam stability (FS) of CD peptide fractions was maximal near neutral pH. For TD peptide fractions, one fraction showed maximal FS at strongly alkaline pH, while the other showed no clear maximal FS. CD related peptide foams contained higher levels of hydrophobic peptides than the respective solutions, while small differences were observed for TD peptide fractions. Peptide compositions of foams did not vary with pH, indicating that the foaming properties of gliadin peptides are mainly dictated by charges. As the pH dependent foaming properties of TD related peptides resemble best those of gliadin, it was concluded that the pH dependent foaming properties of gliadins are mainly determined by their TDs.