Fatty Acid and Tocopherol Composition of Pomace and Seed Oil from Five Grape Varieties Southern Spain

Grape pomace and seeds are important winemaking by-products. Their oils are rich in bioactive compounds such as fatty acids and tocopherols. We have characterized oils from both by-products from five Spanish grape varieties (Palomino Fino, Pedro Ximénez, Muscat of Alexandria, Tempranillo and Tintilla de Rota). A high content of UFAs was found in all the analyzed samples. Grape pomace oils generally had the same oleic acid (PUFA_ω-6) content as seed oils, and lower PUFA contents; they also had a markedly higher linolenic acid (PUFA_ω-3) content, improving the PUFA_ω-6/PUFA_ω-3 ratio. All the oil studied show good indicators of nutritional quality: low values of the atherogenicity (0.112–0.157 for pomace, 0.097–0.112 for seed) and thrombogenicity indices (0.30–0.35 for pomace, 0.28–0.31 for seed) and high values of the relationship between hypo- and hypercholesterolemic fatty acids (6.93–9.45 for pomace, 9.11–10.54 for seed). Three tocopherols were determined: α-, γ- and δ-tocopherol. Pomace oils have higher relative contents of α- and δ-tocopherol, whereas seed oils have higher relative contents of γ-tocopherol. A significantly higher content of total tocopherols has been found in pomace oil; it is higher in the oils from red varieties of pomace (628.2 and 706.6 mg/kg by-product), and in the oils from pomace containing stems (1686.4 mg/kg by-product). All the oils obtained can be considered as a source of vitamin E, and their consumption is beneficial for health.     

Electronic structure and transport on the surface of topological insulator attached to an electromagnetic superlattice

We study the electronic structure and transport for Dirac electron on the surface of a three-dimensional (3D) topological insulator attached to an electromagnetic superlattice. It is found that, by means of the transfer-matrix method, the number of electronic tunneling channels for magnetic barriers in antiparallel alignment is larger than that in parallel alignment, which stems to the energy band structures. Interestingly, a remarkable semiconducting transport behavior appears in this system with a strong magnetic barrier due to low energy band nearly paralleling to the Fermi level. Consequently, there is only small incident angle transport in the higher energy region when the system is modulated mainly by the higher electric barriers. We further find that the spatial distribution of the spin polarization oscillates periodically in the incoming region, but it is almost in-plane with a fixed direction in the transmitting region. The results may provide a further understanding of the nature of 3D TI surface states, and may be useful in the design of topological insulator-based electronic devices such as collimating electron beam.     

Output-only identification and dynamic analysis of time-varying mechanical structures under random excitation: A comparative assessment of parametric methods

This article addresses the problem of parametric time-domain identification and dynamic analysis for time-varying (TV) mechanical structures under unobservable random excitation. The methods presented are based on time-dependent autoregressive moving average (TARMA) models, and are classified according to the mathematical structure imposed on the TV parameter evolution as unstructured parameter evolution, stochastic parameter evolution, and deterministic parameter evolution. The features and relative merits of each class are outlined. A representative method from each is then assessed through its application to the identification and dynamic analysis of a laboratory TV structure consisting of a beam with a mass moving on it. The results are mutually compared and contrasted to those obtained through “frozen-configuration” (multiple experiment) baseline identification.     

用位置灵敏光电倍增管读出的CsI(Tl)探测器

报道了用双维位置灵敏光电倍增管读出的CsI(T1)探测器,其CsI(T1)晶体厚度为10mm,灵敏面积为60mm×60mm.探测器的空间位置分辨为0.81mm(FWHM).用蒙特卡罗的方法对该探测器作了进一步模拟研究,其结果与实际测试的结果很好地一致.     

Computational study of ground-state chiral induction in small peptides: comparison of the relative stability of selected amino acid dimers and oligomers in homochiral and heterochiral combinations

The relative stabilities of homochiral and heterochiral forms of selected dipeptides, AA, AS, AC, AV, AF, AD, AK, tripeptides, AAA, AVA, and an acetylpentapeptide, AcGLSFA, have been calculated using thermodynamic integration protocols and the GROMOS 53A6 force field. Integration pathways have been designed that produce minimal disturbance to the system, including the use of soft atoms, low-energy intermediates, and chiral inversion of the smaller amino acid in the peptide. Comparison of the results obtained by thermodynamic integration between the diastereomeric forms (in explicit water, at 300 K) and from exhaustive global minimum-energy searches for the individual dipeptides (implicit water, epsilon = 78, 0 K) suggests that entropic contributions to the relative stability of the chiral forms are important. This conclusion is supported by the results of explicit calculation of the effect of temperature on the relative stability of alanylvalylalanine diastereomers. The Gibbs free energy calculations predict that at ambient temperature and pressure homochiral dipeptides with small side chains or polar groups in the vicinity of the peptide backbone, AA, AS, and AD, are more stable than their heterochiral counterparts by fractions of a kJ/mol. For bigger side chains, AC, AV, AF, and AK, the heterochiral diastereomers appear to be more stable. Predicted relative stabilities are in line with observations reported in the literature for AE and YY. Excellent agreement is found for the calculated and experimentally determined relative stabilities of the diastereomers of the dipeptide AA and of all-L AcGLSFA and its diastereomer containing D-serine in the central position. Addition of counterions to the solvent box has no significant effects on charged and neutral forms. From the present findings it would appear unlikely that the intrinsic stability difference between homo- and heterochiral dipeptides has been a driving force in a primordial selection process leading to the incorporation of amino acids with a single enantiomeric configuration in natural proteins.     

一种新型数字电感传感器的设计及应用

传统电感测量中由于检测装置结构复杂、采用模拟接口,抗干扰能力差,精度不高等,针对这些缺点,设计了一种低功耗的电感感测装置,采用TI最新推出世界首款电感到数字转换器LDC1000做为探头,通过SPI接口与MSP430G2553实现高速数据采集,使得装置功耗降低,体积减小,数据处理方便快捷。实验证明：该装置能够在恶劣的环境中大大提高可靠性,实现高灵敏度、高速数据处理且运算量小,可应用在灰尘、污垢、油和潮湿等恶劣环境中。     

层次分析法在战术互联网效能评估中的应用

战术互联网作为战术级部队机动作战的信息基础设施，对其进行效能评估具有重要的意义。本文建立了战术互联网的系统层次模型，给出实例说明了利用层次分析法进行战术互联网效能评估的方法，最后的结果表明该方法是有效的。     

Bestimmung der Komponenten eines ternären Systems

Es wird eine schnelle und einfache Methode zur quantitativen Bestimmung der Komponenten eines ternären Systems beschrieben. Sie beruht auf der kombinierten Messung der Rückstreuung und Absorption von β-Strahlung. Als Beispiel wurde das System Na⁺, Ba²⁺, Cu²⁺ gewählt. Der Meβfehler der Methode liegt zwischen 0,5 und 3,5%.     

CsI（Tl）+Si-APD探测器的性能测试

介绍了Si-APD的工作原理并对Si-APD中的暗电流进行了理论分析。基于RIBLL上产生的放射性核束流,使用CsI（Tl）+Si-APD探测器对中能重离子进行了能量测试。测试结果显示,CsI（Tl）+Si-APD探测器测量20 MeV/u的重离子时,可得到3%的能量分辨;同时还发现Si-APD中的暗电流大小以及入射粒子的能量大小都会对探测器的能量分辨产生影响。In this paper, the working principle of Si-APD was introduced and the dark current of Si-APD was analyzed theoretically. The intermediate energy heavy ions, which are produced on the RIBLL(Radioactive Ion Beam Line in Lanzhou), were measured with CsI(Tl)+Si-APD detector. The energy resolution of CsI(Tl)+Si-APD detector is about 3% for heavy ions with energy around 20 MeV/u. It is also found that the energy resolution of detector can be in uenced by the dark current of Si-APD and the energy of incident particles.