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11.
Yan-chun ZHU Qing-xue HUANG Xiao-hui SHI Mei-rong SHUAI Wei-dong ZENG Yong-qing ZHAO Zhi-quan HUANG Li-feng MA 《中国有色金属学会会刊》2018,28(8):1521-1529
The microstructural evolution and precipitation location of the secondary phase of an as-cast Ti-25V-15Cr-0.3Si titanium alloy were investigated via isothermal compression experiments and heat treatment. The average aspect (length-to-width) ratio, average area and size of the grains at different heat treatment temperatures and holding time were analyzed and the effects of deformation and annealing time on the grain area and size were considered. It was found that the grain size was strongly influenced by the height reduction and holding time. Grain growth was significant when annealing time increased from 10 min to 2 h at 950 °C and height reduction of 30%; however, grain growth was minimal at annealing time between 2 and 4 h. Many dispersion particles were observed to form in continuous chains; the precipitation location was confirmed to be along initial grain boundaries, and the dispersion particles were identified to be Ti5Si3 phase by TEM. 相似文献
12.
Gelation properties of goose liver protein recovered by isoelectric solubilisation/precipitation process 下载免费PDF全文
Xin Li Siwen Xue Xue Zhao Xinbo Zhuang Minyi Han Xinglian Xu Guanghong Zhou 《International Journal of Food Science & Technology》2018,53(2):356-364
Isoelectric solubilisation/precipitation (ISP) process was applied to goose liver (GL) for protein extraction. The gelation properties of proteins extracted by acid processes (ACP, pH 2.0, 2.5 and 3.0) and alkaline processes (ALP, pH 11.0, 11.5 and 12.0) were estimated, where the unextracted ground GL was set as the control. Nearly 58.39~79.00% of GL proteins were recovered by ISP treatments. High molecular weight (100~250 kDa) proteins were found to be partially hydrolysed by ACP, while few changes in proteins occurred during ALP. As evidenced by rheological and textural measurements, ALP proteins formed gels with high elasticity and superior texture, whereas ACP proteins had inferior gelation properties. Moreover, ALP proteins were able to form a highly interconnected and homogeneous three‐dimensional microstructure. Predominantly, gels produced by 11.0 had optimal texture and the lowest cooking loss (P < 0.05). These results suggested that the ISP process (ALP) is a potential method to improve the economic value of GL. 相似文献
13.
负载型金属催化剂在水处理中起着重要的作用,浸渍法是制备负载型催化剂的重要方法。为了克服传统浸渍方法的缺点,本文通过使用甘氨酸/盐酸作为缓冲溶液,严格控制pH,获得高分散的活性组分并以此方法制备了铁基类芬顿催化剂。对苯酚催化降解的实验表明,使用缓冲溶液法制备的催化剂比未使用的样品可以更高效地去除苯酚,1h内对苯酚的降解可达89.3%。此外,通过调节浸渍温度、浸渍时间和缓冲溶液的pH等参数来精确控制活性组分的量和催化活性。更重要的是,此催化剂制备方法可以用于其他负载型金属催化剂的制备,比如过硫酸盐催化剂,并取得了良好的催化效果。 相似文献
14.
A facile and effective method was proposed to prepare the molecularly imprinted fluorescence sensor with carbon quantum dots, which were modified vinyl groups by acrylic acid on the surface. The obtained fluorescence composite material was investigated by transmission electron microscope and Fourier transform infrared spectra. After the experimental conditions were optimized, a linear range of 1.0–60 μmol L−1 was obtained and the detection limit was 0.17 μmol L−1. The novel fluorescence sensor can be successfully used to detect tetracycline in real samples. This study provides a convenient strategy for selective recognition and rapid detection of tetracycline in the complex environment. 相似文献
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在Fe-As(Ⅲ)-Cu(Ⅱ)-H2O体系中, 研究了酸性废水中As(Ⅲ)、Cu(Ⅱ)与金属铁粉的反应行为, 考察了反应过程中As在气、液、固三相中的分配比。结果表明, As(Ⅲ)和Cu(Ⅱ)离子被Fe还原为单质As和Cu后, As、Cu进一步结合成Cu5As2等金属间化合物, 从而促进As(Ⅲ)沉淀反应的发生, 且无AsH3生成。在反应时间40min、铁粉过量系数1.2、溶液初始pH=0.0、温度40 ℃、Cu/As摩尔比1.0条件下, As在气、液、固三相中的分配比分别为0、20.7%和79.3%, 沉砷率为79.3%。 相似文献
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18.
研究了一种镍基单晶高温合金SRR99在不同温度下的高周疲劳行为,试样采用[001]取向的单晶试棒。结果表明条件疲劳强度随着试验温度的升高先上升后降低,具有与高温拉伸强度表现出相同的变化规律。通过扫描电子显微镜和透射电子显微镜的观察发现g′相的形貌发生了显著变化,经过高温循环变形后g′析出相发生了溶解。在交变应力的作用下,g′与基体界面产生大量的位错,而位错的往复运动引起了g′相的溶解。因此循环加载过程中伴随着g′的不断溶解,共格界面的强化作用不断减弱。 除此之外,通过裂纹扩展方向与试样轴向的夹角可以判断出疲劳裂纹的扩展主要沿着(111)晶面进行,根据扫描电镜和透射电镜的观察结果对于循环加载的微观组织演化机理进行了讨论。 相似文献
19.
Wax deposit properties are a significant concern in pipeline pigging during waxy crude oil transportation. In the present work, the impacts of flow conditions and oil properties on the wax precipitation characteristics of wax deposits are investigated. A flow loop apparatus was developed to conduct wax deposition experiments using four crude oils collected from different field pipes. The differential scanning calorimetry (DSC) technique was employed to observe the wax precipitation characteristics of crude oil and wax deposit. The results show that the wax content and the wax appearance temperature (WAT) of the deposits increase with shear stress and radial temperature gradient, and decrease with radial wax molecule concentration gradient near the pipe wall. The DSC tests on the wax deposits revealed that the deposit wax content is strongly correlated to the oil wax content. Furthermore, an empirical correlation was developed to predict the wax content and the WAT of the wax deposit. Verification of the empirical correlation using the different oils indicated that the average relative error of the wax content prediction and average absolute error of WAT prediction were 13.2% and 3.6°C, respectively. 相似文献
20.
The combined effect of resistance spot welding and precipitation hardening on the localised corrosion of A286 superalloy is studied. The specimens tested by double loop electrochemical potentiokinetic reactivation were welded in the solution treated condition, and then subjected to different precipitation hardening treatments. For both base metal and weld nugget, the maximum localised corrosion is reached when η phase is clearly observable. The fact that the localised corrosion resistance of weld nugget is different from that shown by base metal may be explained by the segregation of Ni and Ti towards the interdendritic region of weld nugget (studied by using scanning electron microscope/energy dispersive X-ray analysis). 相似文献