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简单讲述了膨胀土的含义同时对经常遇到的膨胀土路基毛病实行划分种类,解析了经常用到的整治方法,以某项目中路基膨胀土为例建议了详细的操纵重点。 相似文献
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用土曲霉植酸酶制备三磷酸肌醇的研究 总被引:3,自引:0,他引:3
研究了用土曲霉植酸酶水解植酸,并对其酶学性质进行了研究,其最佳酶活条件为pH5.10,温度为50℃。采用土曲霉植酸酶部分水解植酸时控制水解条件,当水解度达到50%时,将水解混和物通过717型强阴离子树脂柱,并用0.05~0.7mol/L的HCl溶液进行线性梯度洗脱,洗脱物分别取样消化,检测无机磷含量变化,并将同一峰值部分收集在一起,用NaOH中和,加CaCl2溶液,产生沉淀,过滤,沉淀用HCl溶解,上732型阳离子树脂脱去钙离子,蒸馏水洗脱,用NaOH中和至中性后减压浓缩,冷冻干燥。用该法制备的三磷酸肌醇经NMR检测,主要为1,2,6-三磷酸肌醇。 相似文献
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草土围堰是用一层草一层土再一层草一层土在水中逐渐堆筑形成的挡水结构,为我国传统的河工技术。其主要填筑材料有:草料、土料、制造捆草的长拉绳。文章主要针对现阶段草土围堰施工方法所存在的一些问题进行简要分析与总结,并提出相应地解决措施,仅供参考。 相似文献
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以钠基蒙脱土、丙烯酸类单体和聚乙烯醇为原料,通过溶液原位聚合法和溶液插层法分别制备出不同蒙脱土含量的丙烯酸系共聚物/蒙脱土纳米复合浆料和聚乙烯醇/蒙脱土纳米复合浆料。用X射线衍射(XRD)法测定纳米复合材料中蒙脱土的层间距,并测定纳米复合浆料对纤维的黏附性和浆纱强力。试验结果表明,当蒙脱土含量较少时,形成了剥离型纳米复合材料,随着蒙脱土含量的增加,形成插层-剥离型和插层型纳米复合材料;丙烯酸系纳米浆料有利于提高对纯棉纤维的黏附性,并提高浆纱的断裂强力,而聚乙烯醇纳米浆料可提高对涤/棉的黏附性,对浆纱强力的影响不大。 相似文献
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用于边坡防护的土工合成材料──三维植被固土网垫 总被引:2,自引:0,他引:2
土工合成材料是用于岩土工程或土木工程等工程建设用的聚合物材料的总称,目前主要以聚乙烯、聚丙烯、聚氯乙烯、丙纶、涤纶、锦纶等高聚物为原料,制成的产品主要有四大类:土工布、土工膜、特种土工材料和土工复合材料,在工程中主要起到加强。防护、过滤、排水、隔离和防渗等功能。土工合成材料已广泛应用于水利、水运。堤坝、公路、铁路。机场。环保。城建等领域。土工合成材料的应用解决了许多特殊的和复杂的工程结构问题。提高了工程质量,延长了工程的使用寿命,减少了维护费用,综合经济效益明显。近30年来土工合成材料在世界各国得… 相似文献
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土织布又称为老粗布、手织布,是世代沿用的一种纯棉手工纺织品,在中国纺织史上具有举足轻重的地位。陕西武功土织布技艺已有数千年历史。近年来,在人们崇尚绿色、回归自然的消费观念中,土织布产品受到广泛喜爱。文章系统分析了陕西武功土织布的色彩、图案、材质等三个方面的艺术特征,并深入解读了陕西武功土织布的艺术价值、文化价值、经济价值和环保价值,为更好地传承发展武功土织布提供参考。 相似文献
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用十六烷基三甲基溴化铵(CTAB)对蒙脱土(MMT)进行改性后,与壳聚糖(CS)复合制备壳聚糖/蒙脱土(CS/MMT)复合保鲜膜。通过XRD、FTIR、SEM表征复合膜的结构,并研究了复合膜的拉伸性能和热性能。研究结果表明,随着CTAB用量增大,复合膜的拉伸强度逐渐增大,在CTAB/MMT(w/w)为0.6时拉伸强度达到最大值。XRD和SEM分析证明:CTAB能使MMT层间距增大,改善了MMT在CS中的分散性。采用CTAB改性后,MMT能与CS复合形成插层结构,有效提高了CS/MMT复合膜的拉伸性能。 相似文献
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A.N. Lepper-Blilie E.P. Berg D.S. Buchanan W.L. Keller K.R. Maddock-Carlin P.T. Berg 《Meat science》2014
A 3 × 3 × 2 factorial was utilized to determine if roast size (small, medium, large), cooking method (open-pan, oven bag, vacuum bag), and heating process (fresh, reheated) prevented warmed-over flavor (WOF) in beef clod roasts. Fresh vacuum bag and reheated open-pan roasts had higher cardboardy flavor scores compared with fresh open-pan roast scores. Reheated roasts in oven and vacuum bags did not differ from fresh roasts for cardboardy flavor. Brothy and fat intensity were increased in reheated roasts in oven and vacuum bags compared with fresh roasts in oven and vacuum bags. Differences in TBARS were found in the interaction of heating process and roast size with the fresh and reheated large, and reheated medium roasts having the lowest values. Based on TBARS data, to prevent WOF in reheated beef roasts, a larger size roast in a cooking bag is the most effective method. 相似文献
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虾、蟹壳是虾、蟹加工过程中产生的主要废弃物,含有较大量的蛋白质、灰分和甲壳素,以及少量的脂肪、游离氨基酸和虾青素等。近年来,随着我国养殖、捕捞技术的进步以及伏季休渔制度的实施,虾、蟹产量逐年上升。因此,有效利用虾、蟹壳副产物,开发基于虾、蟹壳废弃物的利用途径和产品类型,以提高产品附加值,减少环境污染,对于虾、蟹产业的健康发展具有重要意义。目前,采用酸碱法制备甲壳素是虾、蟹壳利用的主要方法,该方法易于操作,但能耗高且污染严重,近年来研究人员对传统的酸碱法制备甲壳素的工艺进行了优化,并积极探索酶法和发酵法等新型提取工艺。此外,虾、蟹壳中其他可利用成分(蛋白质、脂肪、钙质和虾青素)的提取和利用也获得了许多研究成果。本文主要综述了虾、蟹壳的组成成分,虾、蟹壳整体利用途径以及虾、蟹壳中甲壳素、蛋白质、脂肪、钙质、虾青素等成分的提取和利用途径的研究进展,以期为虾、蟹壳的高效、低成本、无污染和高附加值利用提供借鉴。 相似文献
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本文研究了25~60 ℃范围内温度对猕猴桃糖蛋白(CGP)及其去糖链蛋白(GPP)吸油性、溶解性、起泡性和乳化性的影响,以及CGP、GPP的浓度及其溶液pH3~7.5和0~5 g/100 mL范围的NaCl离子强度对CGP和GPP溶解性、起泡性和乳化性的影响。结果表明:25~60 ℃温度范围内CGP吸油性、溶解度高于GPP,随温度升高,CGP、GPP溶解度下降,两者的起泡性先降低后升高,CGP乳化性先降低后升高,GPP乳化性先升高后降低;不同pH条件下,CGP的溶解度始终高于GPP,pH3~6范围内CGP、GPP溶解度均先下降后升高,pH3~7.5范围内CGP、GPP起泡性和乳化性先下降后升高;随离子强度的升高,CGP、GPP溶解度均下降,且CGP的溶解度始终高于GPP,CGP的起泡性和乳化性下降,GPP起泡性先下降后升高而乳化性则相反;CGP、GPP起泡性和乳化性均随其浓度的增高而增高,1.0 mg/mL时起泡性和乳化性最高,0.2 mg/mL时最低。 相似文献
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Sneh Punia Bangar N. Afzal Ali Aderonke Ibidunni Olagunju Kristian Pastor Adeleke Omodunbi Ashogbon Kshirod K. Dash Jose M. Lorenzo Fatih Ozogul 《Journal of texture studies》2023,54(1):21-53
Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process. 相似文献
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Fakhreddin Salehi 《Journal of texture studies》2020,51(2):361-370
Hydrocolloids (gums) have a good functional characteristic such as emulsifying, gelling, solubility, and textural improvement. In the bakery products, hydrocolloids were used to improving dough performance, bread and cake characteristics, sensorial quality, and extension the products shelf life. Several studies reported the potential use of hydrocolloids in breads, biscuits, cakes, and pasta formulation. The present review summarized the effect of the most common and new hydrocolloids (xanthan, guar, Arabic, carrageenan, karaya, alginate, acacia, methylcellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, locust bean, balangu seed, wild sage seed, basil seed, and cress seed gums) on the rheological, physicochemical, textural, and quality characteristics of bakery products. Gums addition improved volume and porosity of the breads and cakes. Gums influence on the gelatinization and retrogradation of starch and decreased the retrogradation of starch. In the bakery products, hydrocolloids were used to improving mixing and increasing the shelf life of the products through moisture preservation and avoidance of syneresis in some frozen foods. This study summarized the influence of the most common and new hydrocolloids on the rheological, physicochemical, textural, and quality characteristics of bakery products. Addition of seeds gum to the breads, biscuits, cakes, and pasta formula led to an increase in the viscosity of the batter. Also, the firmness of bakery products showed that they became softer with increasing gum levels. 相似文献
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Narashans Alok Sagar Sunil Pareek Sunil Sharma Elhadi M. Yahia Maria Gloria Lobo 《Comprehensive Reviews in Food Science and Food Safety》2018,17(3):512-531
Fruits and vegetables are the most utilized commodities among all horticultural crops. They are consumed raw, minimally processed, as well as processed, due to their nutrients and health‐promoting compounds. With the growing population and changing diet habits, the production and processing of horticultural crops, especially fruits and vegetables, have increased very significantly to fulfill the increasing demands. Significant losses and waste in the fresh and processing industries are becoming a serious nutritional, economical, and environmental problem. For example, the United Nations Food and Agriculture Organization (FAO) has estimated that losses and waste in fruits and vegetables are the highest among all types of foods, and may reach up to 60%. The processing operations of fruits and vegetables produce significant wastes of by‐products, which constitute about 25% to 30% of a whole commodity group. The waste is composed mainly of seed, skin, rind, and pomace, containing good sources of potentially valuable bioactive compounds, such as carotenoids, polyphenols, dietary fibers, vitamins, enzymes, and oils, among others. These phytochemicals can be utilized in different industries including the food industry, for the development of functional or enriched foods, the health industry for medicines and pharmaceuticals, and the textile industry, among others. The use of waste for the production of various crucial bioactive components is an important step toward sustainable development. This review describes the types and nature of the waste that originates from fruits and vegetables, the bioactive components in the waste, their extraction techniques, and the potential utilization of the obtained bioactive compounds. 相似文献
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通过对纸质文献保存和修复领域专利技术文献的收集、分析、标引和梳理,分析了该领域专利技术分布及专利申请情况,分别探析了脱酸、修补、加固、装裱4种技术的专利技术演进路线,最后对该领域专利技术进行了总结。 相似文献
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In seed extracts of five oilseed species, in bran extracts of three cereal species, and in seed and/or whole berry extracts of 10 berry species, the concentrations of a large number of lignans and the enantiomeric composition of selected lignans were determined. In the case of sesame and hemp seeds, the lignan content and composition of the whole seeds was compared to that of the hulled seeds. The results showed that cloudberry seeds are the third most lignan-rich food source after linseeds and whole sesame seeds, and that most of the berry species analysed were more lignan-rich than the cereal brans. The lignans are concentrated in the hull of the oilseeds and in the seeds of the berries. In most samples, secoisolarici-, pino-, medio-, and syringaresinol were present as a mixture of two enantiomers. 相似文献
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为提高米饭蒸煮品质、延缓米饭回生和改善米饭消化性能,比较不同质量分数低聚果糖、山梨糖醇和麦芽糖醇3 种低能量甜味剂对大米浸泡吸水率、直链淀粉比例、硬度、微观结构、晶体结构、热特性及消化特性等指标的影响。结果表明,3 种甜味剂处理均能够提高大米的吸水率,降低米饭的硬度。此外,低聚果糖、山梨糖醇和麦芽糖醇处理均能降低米饭的体外消化水解率。其中,1.6%低聚果糖处理的大米在浸泡25 min时吸水率提高了11.18%,直链淀粉比例、糊化焓值和放置24 h后硬度分别降低了7.36%、22.91%和21.79%,且与其他处理相比,显著降低了糊化焓值和结晶度,并表现出较好的微观结构和抗回生性。该研究为大米精深加工与方便米饭产品开发提供依据。 相似文献
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Abdo Hassoun 《Critical reviews in food science and nutrition》2017,57(9):1976-1998
Although being one of the most vulnerable and perishable products, fish and other seafoods provide a wide range of health-promoting compounds. Recently, the growing interest of consumers in food quality and safety issues has contributed to the increasing demand for sensitive and rapid analytical technologies. Several traditional physicochemical, textural, sensory, and electrical methods have been used to evaluate freshness and authentication of fish and other seafood products. Despite the importance of these standard methods, they are expensive and time-consuming, and often susceptible to large sources of variation. Recently, spectroscopic methods and other emerging techniques have shown great potential due to speed of analysis, minimal sample preparation, high repeatability, low cost, and, most of all, the fact that these techniques are noninvasive and nondestructive and, therefore, could be applied to any online monitoring system. This review describes firstly and briefly the basic principles of multivariate data analysis, followed by the most commonly traditional methods used for the determination of the freshness and authenticity of fish and other seafood products. A special focus is put on the use of rapid and nondestructive techniques (spectroscopic techniques and instrumental sensors) to address several issues related to the quality of these products. Moreover, the advantages and limitations of each technique are reviewed and some perspectives are also given. 相似文献