榛仁内酯豆腐的制作工艺

本研究以榛仁和黄豆为原料、葡萄糖酸-δ-内酯(GDL)为凝固剂,研究榛仁内酯豆腐的制作工艺。以豆腐的硬度、弹性、内聚性和回复性为指标,通过单因素实验对黄豆与榛仁比例、葡萄糖酸内酯用量、点浆温度及点浆p H条件这四个因素进行筛选,结合正交试验、感官评价和质构分析等方法确定最佳制作工艺,并且对榛仁内酯豆腐与其他常见市售豆腐进行了质构等指标的对比。研究实验结果表明,当黄豆与榛仁比例10:3、GDL添加量1.05 g(GDL/100 g原料)、点浆温度85℃、点浆p H 6.5时,榛仁内酯豆腐的硬度为1±0.21/100 g、弹性为(6.3±0.16)mm、内聚性为0.54±0.01、回复性为1.12±0.21;市售豆腐的硬度为1.4±0.12/100 g与榛仁内酯豆腐硬度差异不显著,并且其感官评分值最高。通过优化榛仁内酯豆腐的各项质构条件不仅提高榛仁内酯豆腐的凝固效果还提高了感官评价得分,得到的豆腐品质结构最好。     

影响油纸电容式套管介质损耗因数(tanδ)增大或不稳定因素的分析

主要介绍了油纸电容式套管生产中能够引起套管ｔａｎδ值增大或不稳定的主要原因及其解决办法。同时指出在套管生产中保持其ｔａｎδ值的正常水平不应造成能源的浪费和生产设备的疲劳, 以及处理套管的ｔａｎδ值不应超越绝缘材料的极限。     

水溶性聚苯胺/Sm0.5Ba0.5Cu0.8Cr0.2O3+δ材料的制备与氨敏性能研究

采用化学氧化法制备了水溶性聚苯胺(PANI),用溶胶凝胶法制备了Sm0.5Ba0.5Cu1-yCryO3+δ(y=0,0.1,0.2,0.3,0.4,0.5, 0.6)(SBCC)粉体,用微粒填充法制备了PANI/SBCC复合材料.利用XRD、EDS、FT-IR、TEM多种手段对产物进行表征,研究其在较低工作温度下(60℃)对氨气的敏感性.结果表明,在同等条件下,在PANI元件、SBCC元件及PANI/SBCC元件中,PANI/Sm0.5Ba0.5Cu0.8Cr0.2O3+δ(PANI/SBC80C20)元件对NH3的气敏性能最优,对体积分数为100×10-6 NH3的灵敏度在60℃条件下达到最大值为3.79,且响应恢复时间短,还具有较好的选择性.     

In Situ Observation of P91 High-Alloy Steel Solidification Characteristics at Different Cooling Rates

To clarify the effect of different radial cooling intensities on the formation of central cracks in large round bloom continuous casting, it is necessary to study the solidification characteristics and dynamics of P91 high-alloy steel at different cooling rates (CRs) to improve the central defects. In this article, the solidification characteristics of P91 high-alloy steel at different CRs are studied by using the Thermo-Calc software, high-temperature laser confocal microscopy, scanning electron microscopy, and optical microscopy. Meanwhile, the growth kinetics of δ-Fe and γ-Fe phases under different CRs are determined. The results show that the solidification path of P91 high-alloy steel is L(L + δ-Fe) → (L + γ-Fe + δ-Fe) → (δ-Fe + γ-Fe). The δ-Fe and γ-Fe phase precipitation process is divided into two stages. Stage I is the nucleation and rapid growth phase, in which a high undercooling is required. Stage II is the slow growth stage, where the undercooling decreases and remains constant. The initial growth linear velocities of the δ-Fe phase are 0.51, 2.72, and 2.09 μm s⁻¹ at CRs of 10, 50, and 100 °C min⁻¹, respectively, while those of the γ-Fe phase are 0.10, 1.42, and 1.41 μm s⁻¹.     

高精度FFT算法在介损监测中的理论与仿真研究

在电力设备介质损耗在线监测中,由于对连续工频周期信号的截断和非同步采样,会给基于传统FFT的谐波分析法带来显著的误差。笔者在前人的基础之上,对高精度FFT算法进行了详细的推导,并给出了加Blackman-Harris窗插值算法的实用公式。针对实际电网频率波动引起的非同步采样,通过MATLAB软件对普通FFT算法、加Blackman窗和加Blackman-Harris窗的插值算法进行仿真。仿真结果分析表明采用加Blackman-Harris窗插值的高精度FFT算法可以有效地降低测量误差和提高监测精度,满足现场电力设备介损监测的要求。     

基于小波能谱熵的tanδ在线监测数据规律研究

针对在线监测电容型设备的绝缘特性变化规律以及受外界因素影响的情况不明确,难以发现其变化来确定设备绝缘状况的问题,提出了基于小波能谱熵理论的数据规律分析方法。该方法利用小波分析具有时频局部化的特性和信息熵对系统状态表征的特性,将小波分析与熵结合起来对信号进行特征挖掘。计算小波能谱熵作为系统的特征参数来识别不同信号的变化趋势并将与tanδ变化最接近的因素作为主导因素来分析。实例分析表明,上述熵值能够反映在线监测tanδ和外界因素的系统变化,以此为参量来分析趋势并进行故障诊断是一种行之有效的方法。     

SrCe0.7Zr0.2Eu0.1O3-based hydrogen transport water gas shift reactor

Proton-transport-membrane water gas shift (WGS) reactors, based on thin dense SrCe_0.7Zr_0.2Eu_0.1O_3−δ membranes on tubular Ni–SrCe_0.8Zr_0.2O_3−δ supports, were developed to increase H₂ yields relative to thermodynamic limitations. Pure H₂ permeate, total H₂ production, and reactor side CO conversion and H₂/CO effluent ratio were measured as a function of temperature, flow rate, CO concentration and H₂O/CO feed ratios. CO conversion, total H₂ production and yield, and the H₂/CO in the reactor side effluent increased with increasing temperature and H₂O/CO feed ratios. CO conversions of 84% and 90% were achieved at 900 °C with H₂O/CO feed ratios of 1/1 and 2/1, respectively. These respective 77% and 44% increases in CO conversion compared to feed gas condition thermodynamics resulted in 73% and 42% increases in H₂ production. Permeated H₂ and total H₂ production increased with increasing flow rate and CO concentration. Finally, membrane stability under WGS conditions was significantly improved by Zr substitution.     

On the hydration of grain boundaries and bulk of proton conducting BaZr0.7Pr0.2Y0.1O3-δ

We report here for the first time bulk and grain boundary conductivities from impedance spectra of a ceramic proton conductor (BaZr_0.7Pr_0.2Y_0.1O_3-δ) taken during hydration and H/D isotope exchange transients (at 400 °C). The results suggest that water moves quickly along grain boundary cores, and then interact from there with the space charge layers and, in turn, grain interiors. Hydration and H/D isotope exchange have simple monotonic effects on the bulk conductivity in line with what is expected from it being dominated by protons. The transients for grain boundary conductivity exhibit however hysteresis: During hydration, the core charge and grain boundary resistance appear to go through transient minima related to non-equilibrium distributions of defects between the core and grain interior – notably because protons diffuse faster than oxygen vacancies between the grain boundary and grain interior. At equilibrium, hydration increases the core charge and the depletion of positive charge carriers in the space charge layers. During H/D isotope exchange relatively fast hysteretic transients indicate that the space charge layers experience changes in charge carrier (D⁺ vs. H⁺) mobility as well as in D₂O vs. H₂O hydration thermodynamics.     

Thermal stability of Ln2NiO4+δ (Ln: La, Pr, Nd) and their chemical compatibility with YSZ and CGO solid electrolytes

Thermal stability and chemical compatibility with electrolyte materials for Solid Oxide Fuel Cells (SOFC) have been studied on Ruddlesden-Popper nickelates Ln₂NiO_4+δ with Ln: La, Pr and Nd. Samples of each composition prepared by three different routes, were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Different microstructures were achieved by each preparation method. The thermal stability of these compounds was analyzed by annealing all the samples at 700 and 900 °C in air. Pr₂NiO_4+δ (PNO) decomposes after 24 h of annealing at 700 °C confirming its instability at these conditions. Evidences of chemical reaction between La₂NiO_4+δ (LNO) and both Ce_0.9Gd_0.1O_1.96 (CGO) and Zr_0.92Y_0.08O_1.96 (YSZ) were observed at 700 and 900 °C, respectively. No decomposition or chemical reaction with YSZ or CGO were found for Nd₂NiO_4+δ (NNO) below 900 °C. Nevertheless, reactivity with both electrolytes was found for this compound at 1000 °C. The kinetics of these reactions strongly depends on the microstructure of Ln₂NiO_4+δ.     

Novel Nd2WO6-type Sm2−xAxM1−yByO6−δ (A = Ca, Sr; M = Mo, W; B = Ce, Ni) mixed conductors

In the present work, we have explored novel Nd₂WO₆-type structure Sm_2−xA_xM_1−yB_yO_6−δ (A = Ca, Sr; M = Mo, W; B = Ce, Ni) as precursor for the development of solid oxide fuel cells (SOFCs) anodes. The formation of single-phase monoclinic structure was confirmed by powder X-ray diffraction (PXRD) for the A- and B-doped Sm₂MO₆ (SMO). Samples after AC measurements under wet H₂ up to 850 °C changed from Nd₂WO₆-type structure into Sm₂MoO₅ due to the reduction of Mo^VI that was confirmed by PXRD and is consistent with literature. The electrical conductivity was determined using 2-probe AC impedance and DC method and was compared with 4-probe DC method. The total electrical conductivity obtained from these two different techniques was found to vary within the experimental error over the investigated temperature of 350-650 °C. Ionic and electronic conductivity were studied using electron-blocking electrodes technique. Among the samples studied, Sm_1.8Ca_0.2MoO_6−δ exhibits total conductivity of 0.12 S cm⁻¹ at 550 °C in wet H₂ with an activation energy of 0.06 eV. Ca-doped SMO appears to be chemically stable against reaction with YSZ electrolyte at 800 °C for 24 h in wet H₂. The ionic transference number (t_i) of Sm_1.9Ca_0.1MoO_6−δ in wet H₂ at 550 °C (pO₂ = 10^−25.5 atm) was found to be about 0.012 after subtraction of electrical lead resistance from the 2-probe AC data and showed predominate electronic conductors.