大豆乳清蛋白及其糖基化产物体外模拟胃肠消化特性研究

体外模拟胃液和胰液对大豆乳清蛋白(WSP)及其糖基化产物的消化特性进行研究。结果表明:当胃蛋白酶和胰酶添加量为底物质量的2%~8%时,仅模拟胃液能部分水解WSP,体外消化率为48.0%~50.2%;胃蛋白酶作用后,SDS-PAGE电泳显示WSP的组分脂肪氧合酶和β-淀粉酶条带消失,而大豆血球凝集素以及胰蛋白酶抑制剂KTI、BBI被部分水解后仍有清晰条带;胰酶作用后,SDS-PAGE电泳显示WSP的各组分条带基本不变;使用葡萄糖在60℃的干热条件下对WSP糖基化改性1~7 d能够提高WSP糖基化产物的乳化特性和热稳定性,相比于WSP,此糖基化产物的体外消化率随反应时间的延长先增加后降低。     

电化学频率调制技术在Q235钢/NaCl腐蚀体系中的应用

分析了主要测量参数对电化学频率调制技术(EFM)测量结果的影响;探讨了校验因子偏离理论值的原因;通过EIS分析以及与线性极化法和失重法的对比实验,研究了在Q235钢/NaCl体系中EFM测量结果的准确性。结果表明:EFM测量基频越高,测量结果误差越大,在Q235钢/NaCl体系中应选取0.01 Hz的基频;校验因子CF3对测量性的判断不可靠,宜以CF2为校验标准;EFM方法测量的极化阻抗值准确性强于线性极化;与失重法的对比实验表明EFM是一种快速准确的腐蚀速率测量方法。     

宁波铁路南站主站房北水滴钢结构临时支撑卸载监测

宁波铁路南站主站房北立面为一个大型"水滴"钢结构造型,悬挑跨度16.3m、横向跨度66.0m、质量达154t、受力复杂、卸载难度大。为确保卸载安全,采用有限元软件分别对4种卸载方案进行卸载全过程仿真分析,得出"从中间往两侧对称卸载"的最佳方案,并确定38个应力监测点和18个变形监测点及其监测预警值。利用MATLAB程序实时计算各测点的实测值,判断其变化趋势,指导现场卸载操作。监测结果表明:应力和变形实测时程曲线基本被仿真曲线包络,实测值和仿真值变化趋势基本一致,北水滴钢结构卸载过程安全可靠;该卸载监测方法科学、实施有效。     

最大似然卷积混合离散信号盲分离

In this paper, a Maximum Likelihood (ML) approach, implemented by Expec-tation-Maximization (EM) algorithm, is pro-posed to blind separation of convolutively mixed discrete sources. In order to carry out the expectation procedure of the EM algorithm with a less computational load, the algorithm named Iterative Maximum Likelihood algorithm (IML) is proposed to calculate the likelihood and recover the source signals. An important feature of the ML approach is that it has robust performance in noise environments by treating the covariance matrix of the additive Gaussian noise as a parameter. Another striking feature of the ML approach is that it is possible to separate more sources than sensors by exploiting the finite alphabet property of the sources. Simulation results show that the proposed ML approach works well either in determined mixtures or underdetermined mixtures. Furthermore, the performance of the proposed ML algorithm is close to the performance with perfect knowledge of the channel filters.     

苹果中根皮苷的测定及其在苹果汁质量控制中应用初步研究

根皮苷是苹果中的特征酚类物质,在苹果汁质量控制和指纹图谱建立中具有重要的意义.建立了苹果根皮苷高效液相色谱(HPLC)测定方法,该方法线性范围0.5～200mg/L,检测限0.3mg,L,定量限0.5mg/L,相关系数r=0.9997,回收率99.7%～101.8%.对我国环渤海湾苹果优势产区6个苹果品种中根皮苷含量进行了分析,并研究了原料品种、产地、加工工艺和贮藏期对苹果中根皮苷含量的影响.结果表明,不同品种、产区苹果以及鲜榨汁与浓缩还原汁中根皮苷含量存在显著差异,将HPLC方法用于苹果汁品质控制和原产地保护可行,还可用于区分苹果鲜榨汁与浓缩还原汁.     

α+β钛合金旋转弯曲疲劳性能各向异性的研究

研究了微观组织和织构对β锻造的α + β两相钛合金镦饼旋转弯曲疲劳性能各向异性的影响,利用OM、SEM、XRD和EBSD等手段表征了镦饼不同方向及不同厚度处的显微组织以及织构分布,分析了微观组织和织构对旋转弯曲疲劳性能各向异性的影响。结果表明,合金经β锻造后,呈网篮组织特征,原始β晶粒压扁拉长,且晶界处存在再结晶晶粒;镦饼形成β相<100>//轴向的丝织构和α相<0001>//径向的织构。径向试样旋转弯曲疲劳强度优于轴向试样,这与镦饼的原始β晶粒形态和织构类型均有关,原始β晶粒的排布导致不同取向裂纹萌生的难易程度和裂纹扩展路径曲折程度不同;此外,α相和β相织构也造成不同取向在循环加载时滑移系开动难易程度不同造成疲劳强度产生差异。     

基于Intel~(TM)i860微处理器和Bt463的并行图形成象系统

本文设计了一种基于ＩｎｔｅｌＴＭｉ８６０微处理器及Ｂｔ４６３ＲＡＭＤＡＣ的小型并行计算机图形显示系统，实现了１０２４×１０２４分辨率，２４位真彩色的三维图形系统。     

Preparation and characterization of Pd/Si-MCM-41 with high hydrogenation activity

The pure silica mesoporous molecular sieve MCM-41 was synthesized under hydrothermal conditions. Pd/Si-MCM-41 was prepared by the incipient wetness impregnation of pure silica MCM-41 with PdCl₂ as precursor. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms at 77 K, inductively coupled plasma (ICP) spectroscopy measurements. The formation of Pd particles reduced the crystalline character of Si-MCM-41, but the structure of Si-MCM-41 framework was retained. The designed Pd/Si-MCM-41 mesoporous material was used as catalysts for hydrogenation of rosin, and showed excellent catalytic performance. Such outstanding catalytic performance should be attributed to the proper size of Pd particles and its high dispersion.     

Automatically detect and track infrared small targets with kernel Fukunaga-Koontz transform and Kalman prediction

Fukunaga-Koontz transform (FKT), stemming from principal component analysis (PCA), is used in many pattern recognition and image-processing fields. It cannot capture the higher-order statistical property of natural images, so its detection performance is not satisfying. PCA has been extended into kernel PCA in order to capture the higher-order statistics. However, thus far there have been no researchers who have definitely proposed kernel FKT (KFKT) and researched its detection performance. For accurately detecting potential small targets from infrared images, we first extend FKT into KFKT to capture the higher-order statistical properties of images. Then a framework based on Kalman prediction and KFKT, which can automatically detect and track small targets, is developed. Results of experiments show that KFKT outperforms FKT and the proposed framework is competent to automatically detect and track infrared point targets.     

High performance solid oxide electrolysis cells using Pr0.8Sr1.2(Co,Fe)0.8Nb0.2O4+δ–Co–Fe alloy hydrogen electrodes

A novel ceramic hydrogen electrode material consisting of K₂NiF₄-type structured Pr_0.8Sr_1.2(Co,Fe)_0.8Nb_0.2O_4+δ (K-PSCFN) matrix with homogenously dispersed nano-sized Co–Fe alloy (CFA) has been demonstrated by annealing perovskite Pr_0.4Sr_0.6Co_0.2Fe_0.7Nb_0.1O_3−δ (P-PSCFN) in H₂ at 900 °C. Impedance spectra and voltage–current density curves of the La_0.8Sr_0.2Ga_0.83Mg_0.17O_3−δ (LSGM) electrolyte supported solid oxide electrolysis cell (SOEC) with a configuration of K-PSCFN–CFA/LSGM/Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3−δ (BCFN) have been evaluated as a function of the operating temperature and feeding gas absolute humidity (AH) to characterize the cell performance. Cell polarization resistances (R_p) were as low as 0.77 and 0.31 Ω cm² under open circuit voltage (OCV) and 60% absolute humidity (AH) at 800 and 900 °C, respectively. The cell has demonstrated good stability for high temperature stream electrolysis, and a hydrogen production rate of 707 ml/cm² h calculated from the Faraday's law has been achieved under an electrolysis voltage of 1.3 V and 60 vol.% AH at 900 °C. The cell performance results indicate that K-PSCFN–CFA is a promising hydrogen electrode for high temperature solid oxide electrolysis cells.