共查询到19条相似文献，搜索用时 312 毫秒
1.
《广东海洋大学学报》2019,(6)
【目的】研究金鲳鱼(Trachinotus ovatus)鱼皮明胶流变性质。【方法】利用氨基酸分析仪测定明胶的氨基酸组成,并对66.7 g·L-1明胶凝胶的动态粘弹性进行分析比较。【结果】金鲳鱼皮明胶氨基酸组成中每1 000总氨基酸残基中甘氨酸为334个,亚氨基酸脯氨酸和羟脯氨酸共184个,凝胶强度为342 g;66.7 g·L-1金鲳鱼皮明胶溶液粘度为7.13 cp,凝胶温度及熔胶温度分别为20.4℃和28.3℃,乳化性及乳化稳定性分别为8.32 m2/g、34 min。【结论】金鲳鱼皮明胶凝胶强度优于牛骨明胶,凝胶温度、熔胶温度低于牛骨明胶,更适合应用于要求低温贮藏的可食膜或微胶囊基料。 相似文献
2.
【目的】制备壳聚糖CS-大豆蛋白SPI-百里香酚Thy乳液(CST),探究其对大口黑鲈(Micropterus salmoides)的保鲜效果。【方法】设置大豆蛋白添加量分别为1.6%、2.4%、3.2%、4.0%、4.8%(质量分数),制备不同大豆蛋白浓度的壳聚糖-大豆蛋白-百里香酚复合乳液(其中壳聚糖质量分数为0.5%,百里香酚质量分数为1.0%),研究其结构、乳化能力和乳液稳定性等。将经最佳配比CST乳液处理后的大口黑鲈肉块与未进行处理的对照组在10℃下贮藏,检测贮藏过程中鱼肉pH、挥发性盐基氮和菌落总数等指标,验证乳液的保鲜效果。【结果】在大豆蛋白质量分数为3.2%时,CST乳液乳化稳定性指数(ESI)和乳液乳化活性指数(EAI)达到最大值,分别为(0.92±0.18)%和(8.85±0.13)m2/g;此时,粒径较小,为(13.05±0.05)μm;Zeta-电位较高,达到(39.64±0.83)mV;表面疏水性指数最大,美拉德反应物生成指数最高,内源性荧光强度最大,乳液稳定指数最佳。乳液处理后的鱼肉pH、挥发性盐基氮和菌落总数结果远优于对照组,在10℃... 相似文献
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蜡沉积影响深水油井井筒流体的温度和压力分布.考虑蜡沉积对深水油井井筒多相流流动特性及传热过程的影响,建立蜡沉积井筒温度、压力场模型,分析产量、地温梯度、管柱管径等因素对井筒蜡沉积速率、温度和压力分布的影响.结果表明:随产量增加,蜡沉积层厚度与沉积速率沿井深从下往上呈现先减少后增加的趋势;随地温梯度增加,最大蜡沉积速率与沉积厚度减少;随管柱管径增加,蜡沉积速率与沉积厚度减少.随蜡沉积时间增加,井筒蜡沉积区域的流体温度随之增加,相同条件下沉积速度趋于减小,井筒压力变化不大.该结果可为蜡沉积油井井筒流体流动状态和传热分析提供指导. 相似文献
4.
本文介绍了珍珠加工的基本原理,并提出作为评判珍珠加工质量的简单标准。利用优选法优选影响珍珠加工周期和加工质量的有关因子,同时合理安排多配方协同作用的结果,逐步总结出“ZP—Ⅱ珍珠漂白法”。“ZP—Ⅱ珍珠漂白法”比原工艺“ZP—珍珠漂白法”缩短了加工周期一半,并明显提高了珍珠加工质量。 相似文献
5.
为解决化学驱油体系中无机碱引起地层黏土膨胀、注采系统结垢等问题,充分发挥碱的作用,降低由传统无机碱带来的不利影响,以乙二胺(EDA)作为碱剂,与十二烷基苯磺酸钠(SDBS)复配,与孤东油田原油制备乳状液,考察温度、含水率、SDBS及EDA单独使用和复配使用时的质量分数、乙醇助剂等因素对乳状液的影响,使用析水率和微观结构观测相结合的方法分析乳状液的稳定性.结果表明,当温度低于70℃时,随着温度的升高,原油黏度下降很快;乳状液黏度随含水率的增大先升高后降低,含水率为50%时的黏度最高;50℃、油水质量比为1∶1时,质量分数不超过0.100%的SDBS和EDA单独使用时乳状液的析水率达到50%以上,乳化油滴数量较少;二者复配使用时乳状液的析水率可降至38%,且乳化油滴数量多,稳定性增强;质量分数为0.100%的乙醇助剂的加入可进一步使乳状液的析水率降至30%. 相似文献
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7.
在室内控制条件下,研究了几种环境因素对西施舌稚贝生长发育的影响。结果表明,西施舌稚贝最适生长温度为25.50~27.40℃,最适盐度为24.16~25.66,适应pH为7.5~8.5。壳长1 000~1 200μm的稚贝,在气温25℃与30℃时,干露时间不宜超过25 min;中砂有利于稚贝附着与生长。立体培育的西施舌稚贝,活动强、生长快。 相似文献
8.
利用元素分析仪和原子吸收光谱仪分析了褶纹冠蚌(Cristaria plicata Leach)的四个不同培育阶段的珍珠的十三种元素的含量,以期从连续动态的角度探讨珍珠的形成机制。结果表明,随着育珠时间的延长,珍珠中Ca元素的含量是逐渐增加的,C和H元素的含量则是逐渐下降的。在微量元素中,Na、Cu、Zn、Mg和Sr的含量比较高,其中Na在晚期的珍珠中的含量显著高于早期的珍珠,而CuZn、Mg等其它微量元素则是在早期珍珠中的含量明显高于晚期珍珠,它们随着育珠时间的延长呈指数下降。 相似文献
9.
李笑薇 《东北石油大学学报》2012,(5):72-75,3
在地层温度45℃条件下,开展强碱三元复合体系与大庆原油多次乳化实验,分析多次乳化后水相的化学剂组成及性能.结果表明:聚合物质量浓度降低主要为水解作用;表面活性剂和碱质量分数随乳化次数增多而降低;该表面活性剂构成合理,与大庆原油配伍性好;复合体系在乳化第5次仍与原油有较低的界面张力;多次乳化过程中存在水中含油过饱和阶段.这为加强复合体系与大庆原油乳化作用和三元体系动态驱油机理的认识,为化学驱油配方筛选及机理研究提供参考. 相似文献
10.
青鳞鱼蛋白复合酶控制水解物功能特性的研究 总被引：1，自引：0，他引：1
研究了青鳞鱼蛋白复合酶控制水解产物的功能特性。结果表明,复合酶控制水解能够显著地改善水解物的溶解性、乳化活力及起泡性能。水解物在pH 2.0~10.0范围内其NSI为89.3%~98.5%,且在酸性范围NSI高于碱性范围;在酸性pH内水解物的乳化活力都高于112 m2/g,随着DH的增加,最大乳化活力出现的pH范围更宽广,但水解却降低了乳化稳定性。蛋白质质量分数为1%~5%时,FP随质量分数的增加而增加;泡沫形成后,未水解的蛋白质具有最高的稳定性,DH为8.4%的水解物具有最高的稳定性。 相似文献
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几种因子对鞍带石斑鱼精子活力的影响 总被引：3，自引：0，他引：3
研究不同梯度的盐度、pH、温度及低温保存时间对鞍带石斑鱼精子活力的影响。结果表明:鞍带石斑鱼精子活力的适宜盐度范围为27.5～35.0,最适盐度为32.5,此时精子的快速运动时间和寿命分别为13.2min和14.8min;最适pH为8.5,精子的快速运动时间及寿命最长,分别达12.7min和17.3min;温度范围为27～31℃,以29℃时快速运动时间最长,达16.6min;在0～4℃冰箱保存6h后鞍带石斑鱼精子活力未显著降低,其中保存前精子快速运动时间为18.4min,保存6h后为18.2min,保存120h后仍有活力,精子快速运动时间为2.3min,精子激活率为3.3%。以x为保存时间,快速运动时间y和寿命y′符合线性方程y=-0.8334x+19.164(R2=0.9856),y′=-1.1358x+27.8(R2=0.9573)。 相似文献
12.
《中国海洋湖沼学报》2017,(4)
Over-summering is a crucial period for Calanus sinicus in the southern Yellow Sea,where it is a key member of the zooplankton community.Lipids play an important role in copepod diapause,which is part of their over-summering strategy.We investigated how different fatty acids and lipid classes,including wax esters,changed during over-summering of C.sinicus during three cruises in June and August 2011 and November 2010,corresponding to the pre-,during and post-diapause periods,respectively.Large amounts of lipids were accumulated,mainly wax esters as previously found in C.finmarchicus during its diapause,and most of the storage lipids were used during over-summering.Wax ester polyunsaturated fatty acids(PUFAs) showed the most variation of the fatty acids(FAs),while the percentage composition of FAs in polar lipids was relatively stable.Selective use of wax ester PUFAs has already been shown to play important roles in the winter diapause of Calanus species in other regions,and our FA results show that this is the case for the Yellow Sea Cold Bottom Water(YSCBW) population that diapauses in summer. 相似文献
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Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries. 相似文献
14.
G.Roland Nguimbi 《世界地质(英文版)》2012,15(2):120-125
The electrical heating experiments on oil shale sample from Huadian of Jilin were carried out by the pyrolysis method at three different heating rate 2℃/ min,5℃/ min and 10℃/ min in the temperature range of 30℃-750℃ . Heating rate 2℃/ min is considered low,while intermediate one covers the range 5℃/ min and high heating rate is 10℃/ min. The controlling parameters studied were the final pyrolysis temperature and the influence of the heating rate as well as type. The heating rate has an important effect on the pyrolysis of oil shale and the amount of residual carbon obtained therefore. It is found that increasing the heating rate and pyrolysis temperature also increases the production of oil and the total weight loss. Higher heating rates resulted in higher rates of accumulation. The rate of oil and water collection passed through the maximum of different heating rates at different pyrolysis temperatures. Heating rate affected density,oil conversion and oil yield. 相似文献
15.
The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae （ Chlamydomonas sp. ICE-L） in the low-temperature stress were examined. The plasmalemma of 1CE-L could maintain the stability at the freezing condition of -6 ℃. That signifies that it could maintain the proper function of plasmalemma and stability of the intracellular environment during sea ice formation. The function of inorganic ions on low-temperature adaptation of ICE-L was investigated by using the X-ray microanalysis method. Low temperature （0 - -6 ℃ ） induces Ca^2 ＋ concentration increment of cytoplasm, but after 24 h the content decrease quickly to normal value. As a matter of fact, Ca^2 ＋ plays an important role as the second messenger in the low temperature adaptation of ICE-L. In addition, low temperature also influences on the other primary inorganic ions transfer and the cell maintains activity by keeping ratio balance among different ions. Above all, it is necessary for Antarctic ice microalgae to survive and breed by maintaining the stability of K^ ＋ content and the balance of Na^ ＋/Cl^ -. 相似文献
16.
PVC/蒙脱石(粘)土纳米复合材料研究进展及其应用 总被引：3，自引：0，他引：3
总结分析了PVC/蒙脱石(粘)土纳米复合材料的研究进展,并对其应用进行综述。采用熔融插层、悬浮聚合及乳液聚合等方法可以制备PVC/蒙脱石(粘)土纳米复合材料,并被应用到工程材料、阻隔性材料、功能性材料等领域。PVC/蒙脱石(粘)土纳米复合材料与传统的复合材料相比,表现出了更优越的综合性能,且比传统的复合材料轻,具有高强度、高模量、高耐热性、低吸湿性、高尺寸稳定性、阻隔性能好,性能全而超过了PVC树脂。PVC/蒙脱石(粘)土纳米复合材料不仅具有良好的加工性能,与普通的玻璃纤维增强和矿物增强PVC相比,具有密度低、耐磨性好、综合性能优等特性。 相似文献
17.
以苏州城北路人民路段综合管廊矩形顶管工程为例，分析了影响矩形顶管顶进力的关键因素，提出了管节配重、管节涂蜡和管节注浆等综合减阻方法以降低管壁摩阻力。在管节内放置重物平衡管节所受周围泥浆的浮力；通过涂蜡和喷蜡使管壁光滑，降低管壁与周围介质的摩擦系数；选择合适的材料和配比配制适合地层的泥浆，调整注浆量和注浆压力，使管节周围形成完好的泥浆套。基于实测顶进力与理论计算值的对比分析表明，管壁单位面积摩阻力降低了40%左右，证实该综合减阻方法解决了人民路段矩形顶管顶进力过大的问题。 相似文献
18.
以月腹刺鲀(Gastrophysus lunaris)卵巢为原料,利用超声波辅助提取河豚毒素(Tetrodotoxin,TTX)。通过单因素实验及二次回归旋转组合设计实验研究液料比、超声温度、超声时间等因素对提取率的影响,确定超声波辅助提取河豚毒素的最佳工艺条件。结果表明:在实验范围内影响河豚毒素得率的各因素大小依次为液料体积质量比、超声温度、超声时间;超声波辅助提取河豚毒素的最佳工艺条件为液料体积(mL)质量(g)比3.03∶1,超声温度39℃,超声时间22 min,该工艺条件下提取河豚毒素得率为63.57μg/g。 相似文献
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Microorganisms living in polar zones play an important part as the potential source of organic activity materials with low temperature characteristics in the bio-technological applications. A psychrotrophic bacterium (strain Ar/w/b/75°/10/5) , producing cellulose at low temperatures during late-exponential and early-stationary phases of cell growth, was isolated from sea ice-covered surface water in Chuckchi Sea, Arctic. This bacterium, with rod cells, was Gram-negative, slightly halophilic. Colony growing on agar plate was in black. Optimum growth temperature was 15℃. No cell growth was observed at 351 or above. Optimum salt concentration for cell growth was between 2 and 3 % of sodium chloride in media. Maximal cellulase activity was detected at a temperature of 35℃ and pH8. Cellulase was irreversibly inactivated when incubated at 55℃ within 30 min. Enzyme can be kept stable at the temperature no higher than 25℃. Of special interest was that this bacterium produced various extracellular enzymes i 相似文献