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1.
α-Al2O3 platelets were prepared by a molten salt synthesis method when NaAlO2 was used as raw material. The effects of the stirring rate during the gel preparation, heating temperature, type and addition amount of molten salts, addition of plate-like α-Al2O3 seeds, additives such as TiOSO4 and Na3PO4·12H2O on the morphology of α-Al2O3 were studied. High stirring rate during the gel preparation and high heating temperature not only help to restrain the overlapping of α-Al2O3 platelets, but also improve the size distribution. When the heating temperature increases to 1200 °C, most of α-Al2O3 platelets are hexagonal in its morphology, and the size of platelets becomes relatively uniform. When Na2SO4-K2SO4 flux is used instead of NaCl-KCl flux, it is easy to obtain α-Al2O3 platelets with a big size. When the molar ratio of salt to final Al2O3 powders increases to 4:1, most of α-Al2O3 platelets are hexagonal, and the overlapping of powders is inhibited. The addition of a small amount of plate-like seeds has a significant effect on the size of α-Al2O3 platelets. With the increase of seed amount, the diameter of α-Al2O3 platelets tends to decrease. The addition of 5.45 wt.% TiOSO4 results in the formation of hexagonal α-Al2O3 platelets with an average diameter of 5.1 μm and an average thickness of 1.4 μm. Thin α-Al2O3 platelets with a discal shape are obtained owing to the co-addition of 0.51 wt.% Na3PO4·12H2O and 3 wt.% TiOSO4.  相似文献   
2.
Several winemaking techniques have been developed to eliminate seeds to prevent the release of high amounts of very astringent proanthocyanidins, especially when the grapes are unripe. However, there is no scientific information on the effects of this practice. The aim of this paper is to study how the elimination and addition of seeds influence the colour, phenolic composition and astringency of red wine. The elimination of around 80% of the seeds led to a significant decrease of colour intensity and anthocyanin concentration. The addition of seeds originated wines with a greater concentration of total anthocyanin, but did not significantly affect the wine colour. These wines also presented significantly higher levels of proanthocyanidins, a greater proportion of epicatechin-3-gallate, a lower mean degree of polymerization, and, in particular, a drastic increase in astringency. Wines obtained with the elimination of seeds, on the other hand, had exactly the opposite characteristics.  相似文献   
3.
响应面优化超声波辅助水酶法提取蜡梅籽蛋白   总被引:1,自引:0,他引:1  
采用超声波辅助水酶法提取蜡梅籽蛋白,探讨超声波处理时间与温度、酶用量、碱浸提液pH、酶解温度、酶解时间及料液比对蜡梅籽蛋白提取效果的影响。应用Box-Behnken设计4因素3水平的试验,依据响应面分析确定最优的提取工艺条件。结果表明,最佳提取工艺参数为:超声波处理时间15min,超声波处理温度50℃,料液比1:8,酶用量3.64%,碱浸提pH9.72,酶解温度45℃,酶解时间163min。在此条件下,蜡梅籽蛋白的得率为31.95%。  相似文献   
4.
5.
对2010年3月2日~11日低温阴雨条件下19个甘蓝型油菜品种有效结角率、每角粒数、千粒重和种子含油量进行了分析。结果表明:(1)开花后低温阴雨导致油菜有效结角率下降(平均为对照的72.81%),每角粒数减少(是对照的57.32%),种子千粒重稍有增加(是对照的119.79%),含油量降低(是对照的95.31%)。(2)开花时低温阴雨导致有效结角率下降(是对照的46.01%),每角粒数减少(是对照的33.11%),千粒重有所增加(是对照的114.67%),含油量降低(是对照的96.71%)。(3)开花时低温阴雨对所有供试品种的有效结角率、每角粒数影响均大于开花后。(4)花期低温阴雨的影响因品种而异,希望98、中油821等7个品种抗耐性好。同一品种对开花期和开花后低温阴雨的抗耐性基本一致。  相似文献   
6.
Melon seeds are an important source of bioactive compounds, which are considered to be health beneficial. Therefore, the objective of this work was to assess the impact of gaseous ozone treatments (30 and 60 min) on melon seeds paste (nonedible part) and compare with the effect on pulp (edible part). Ozone treatments were evaluated in terms of physicochemical (color, pH, and soluble solids content) and nutritional profiles (total phenolics, total carotenoids, and total antioxidant capacity) of processed material. Results indicate that ozone has a different impact on the two fruit matrices, being seeds less affected by this preservation treatment.  相似文献   
7.
电场处理烤烟种子,对幼苗及大田烟株生长有一定促进作用,主要表现在叶面积增大,茎杆增粗。有提高产量,增加产值的效果,每666.7 m2面积上比对照增值27.13~60.75元。有改善品质,提高均价的效应,尤其是提高上等烟比例较为显著。每kg均价增加0.165~0.22元,上等烟比例增长10.47%~12.78%。化学成分谐调。电场处理的效应以1 h 7 kv/cm、5 kv/cm电场强度为好。   相似文献   
8.
The manufacture of β-Si3N4 seeds by self-propagating high temperature synthesis (SHS) presents some advantages, such as the low production costs, compared to other preparation methods based on sintering of α-Si3N4 powders and subsequent leaching out of the glassy phase. However, SHS process produces seed clusters that must be disentangled before use as reinforcing particles. Different mechanical and chemical treatments were tried to achieve good seed dispersion, proving that a combined treatment based on a hot basic etching and a short time attrition milling gave almost agglomerate-free particles with adequate features for seeding use.  相似文献   
9.
目的观察在不同温度保存条件下噬菌体展示的1型糖尿病疫苗种子的稳定性。方法将噬菌体展示的1型糖尿病疫苗种子样品分为两组,一组添加等体积的80%甘油,另一组不添加甘油,分别于不同温度条件下存放不同时间后取样,用噬斑法检测滴度。结果在37℃和25℃条件下保存,噬菌体疫苗种子滴度下降较快,在4℃和-20℃条件下保存噬菌体疫苗种子滴度下降相对较慢;37℃、25℃及4℃条件下保存,添加甘油并无明显的保护作用,而在-20℃条件下保存,添加甘油有明显的保护作用。结论噬菌体展示的1型糖尿病疫苗种子可在4℃条件下短期保存,-20℃条件下长期保存,并可添加甘油作为保护剂。  相似文献   
10.
Subcritical fluid extraction (SFE) technology was used to extract oil from Nitraria tangutorum seed. The best possible combination of extraction parameters was found using response surface methodology (RSM) in a three-variable, three-level Box-Behnken experimental design (BBD). The optimum extraction parameters were an extraction time of 40 min, an extraction pressure of 0.60 MPa, an extraction temperature of 44 °C and a raw material particle size of 0.45 mm. Conventional solvent extraction and supercritical CO2 fluid extraction were comparatively used. The yield of seed oil obtained using SFE was 12.92%, which was similar to or higher than the other methods. The chemical compositions of the seed oil, determined by GC–MS, indicate that its unsaturated fatty acids content was 97%. SFE proved to be an effective technique for extracting oil from N. tangutorum.  相似文献   
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