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1.
Six genotypes of sweet potato commercially available in Taiwan, including TNG57, TNG66, TNG68, TYY1, RP and WP, were used as samples in this study of the effects of steaming and kneading with pre-steaming treatments on the antioxidant components and antioxidant properties of methanolic extracts. Steam treatment increased the total phenols contents of all genotypes (2–13 times), flavonoids content of RP (1.3 times) and anthocyanins contents of RP and WP (5–6 times). Steam treatment also increased the reducing power and scavenging DPPH radical effect of sweet potato flours. For the methanolic extracts of steamed and kneaded flours, reducing powers were 0.02–1.70 at 5.0 mg ml−1 and the scavenging effects on DPPH radicals were 19–92% at 2.5 mg ml−1. Both showed the order of RP > WP > TYY1 and TNG66 > TNG57 and TNG68. However, the chelating effect of the six genotypes at 1.0 mg ml−1 ranged from 50% to 73%. Contents of total phenols, flavonoids, and anthocyanins of sweet potato flours were significantly positively correlated with the reducing power and scavenging DPPH radical effects. After steaming and kneading treatments, RP showed the highest increase in the contents of total phenols, flavonoids and anthocyanins among the six genotypes studied.  相似文献   
2.
In real speech, not like lexical words (LWs), prosodic words (PWs) are basic rhythmic units. The naturalness of a Text-to-Speech (TTS) system is directly influenced by the segmentation of the PWs. Most of the PWs are the combination of several LWs. In this paper, three Lexical Combination Models are proposed to combine LWs into PWs, including a Directed Acyclic Graph Model, a Segmentation Model and a Markov Model (MM). To cope with the situation where some long LWs should be segmented into two or more PWs, a Lexical Split Model (LSM) is applied to the long LWs. Experimental results prove that relatively constant results with various training data can be obtained from a MM. The Transformation-Based Error Driven Learning (TBED) algorithm, for its high performance of individual property, is applied in combination with the MM to improve the precision of PW segmentation. Experiments show that among the three proposed models, the MM combined with TBED and LSM, leads to the best performance, in which a precision of 93.00% and a recall of 93.23% are achieved. The perception test indicates that by using PWs as the lowest prosodic units a speech sounds more natural and acceptable than by using LWs. This paper is supported by NSFC Project (60503071); 973 Natural Basic Research Program of China (2004CB318102); Postdoctor Science Foundation of P. R. China (20070420275).  相似文献   
3.
The oxygen absorption process in highly aligned YBa2Cu3Ox samples in air and in pure oxygen was studied at several constant temperatures. The process can be expressed in two steps, a chemical reaction controlled step and a diffusion controlled step. The kinetic equations are as follows respectively:
(1 − at) ln(1 − at) + at = kDt

The activation energy was calculated using an Arrhenius equation. The technical conditions of heat treatment for oxygen absorption of highly aligned YBa2Cu3Ox crystals are discussed.  相似文献   

4.
研究柔性冗余度机器人的残余振动主动控制问题,设计了具有压电作动器与应变传感器的机敏杆件,建立了受控系统的状态空间表达式,采用独立模态空间控制理论设计LQR状态反馈控制器,并基于对偶原理设计了具有指定收敛特性的Luenberger全维状态观测器,最后,以平面3R柔性冗余度机器人为例进行了计算机仿真,结果表明,采用这种主动控制方法可以显著改善柔性冗余度机器人的动力学品质。  相似文献   
5.
C-VISION中文窗口系统综合采用了面向对象与窗口环境设计的程序方法,彻底更新了在微机上进行中文窗口设计的编程思想,同时作为一个基础系统,为软件设计节约了大量的人力和时间,实现了微机程序的共享。  相似文献   
6.
旋风分离器是一种应用离心力进行粉体分离的设备。低温粉碎系统应用它分离粉体并起集粉作用。它的效率决定了物质回收率。本文从离心加速度与重力加速度的比值,筒体的高低,筒体直径,进口速度叙述对分离器效率的影响。着重叙述筒体直径确定方法,以及我们设计造长筒形旋风分离器的具体结构和令人满意的试验结果。  相似文献   
7.
An algorithm to generate the molecular graphs of the trivalent clusters is presented. All the polyhedral trivalent cages with 4-16 vertices are enumerated, with particular attention being given to their symmetry, spectra and stability. The relative stability of isomers is not decided solely by their symmetry. A new kind of spectral phenomenon is reported. This is the occurrence of graphs having the same HOMO-LUMO gap, the same E and the same even-order moments. We refer to it as 'pseudo-isospectrality'.  相似文献   
8.
利用循环流液相等电聚焦技术,对Hb、Cyt.C和BSA混合物进行分离,对RNaseA粗制品进行精制。该方法上样量大,活性回收好。对聚焦过程中扩散、对流和电渗的影响进行了讨论。  相似文献   
9.
The feasibility of the anodic protection of titanium evaporators in Al2(SO4)3 solution was studied by the measurement of polarization curves, weight loss, solubility of passive film and AC impedance. The protection parameters and efficiency were determined. In addition, the practical technology of anodic protection was studied by screening reference electrodes and auxiliary cathodes. Throwing power was also measured. Four rows of tube-type evaporators of titanium have been anodically protected in situ. Field tests lasting more than one year show satisfactory results.  相似文献   
10.
A simple micromechanical model based primarily upon the rule-of-mixtures is developed which allows prediction of the effects of fibre preload on the ply stresses (i.e., the initial residual stresses of fibre, adhesive and matrix) induced within VIRALL laminates, and the tensile stress-strain curves and mechanical properties of VIRALL laminates. The analysis of the ply stresses of VIRALL laminates indicates that pre-stressing will dramatically influence the ply stresses. The predicted tensile stress-strain curves of VIRALL laminates are in good agreement with the experimental curves and the results show that the stress-strain curves of VIRALL laminates move upwards when the prestress increases. The predicted tensile mechanical properties of VIRALL laminates at room temperature show good agreement with those obtained experimentally; both show that prestress can improve the tensile properties (i.e., elastic limit strength, 0.2% yield strength and failure strength) of VIRALL laminates.  相似文献   
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