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1.
超声波对丰年虫卵孵化的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
研究了固定频率和强度的超声波对饵料生物丰年虫卵(chirocephalus)化的影响。实验结果表明,在适宜的超声波辐照下,丰年虫卵的孵化率比对照组提高8%,孵化时间提前2h。  相似文献   

2.
本文针对超声波气体流量计,提出了一种基于模型的超声波渡越时间测量的新方法。该方法首先通过超声波接收探头获取声波信号,然后建立超声波接收信号从起振到稳定的数学模型,最后通过模型参数拟合得到渡越时间参数最优值。作为初步研究,在内径100 mm管径下分别进行了静态和动态渡越时间测量实验。研究结果表明,建立的超声波接收信号的模型是有效的,提出的基于模型的超声波气体流量计渡越时间测量方法是可行的。  相似文献   

3.
通过测量超声波在固体介质中传播的纵波传播速度,进一步测量该固体的杨氏模量,得到了测量固体杨氏模量的一种新方法。  相似文献   

4.
介绍一种利用双频共焦超声波获取组织内部特性信息的新方法一超声激发声发射(USAE)。本文着重说明了USAE的基本工作原理,然后介绍了USAE在医学成像和组织无损测温两方面的重要应用。最后指出了一些有待研究的问题。  相似文献   

5.
介绍一种测量空气中超声波声速的新方法--改变频率干涉法(也叫改变频率驻波法).并对实验数据、测量精度进行了分析.  相似文献   

6.
介绍了一种超声波抑霜新方法。对频率20 kHz的超声波作用下铝表面液滴的雾化现象进行了可视化观测。对不同超声输入功率以及不同超声作用时间下,70 mm×70 mm×3 mm铝表面液滴群的雾化概率进行了分析。试验结果发现,超声波可以瞬间雾化铝板表面液滴;随着超声输入功率的增加,铝表面液滴雾化概率逐渐增加;功率越低,超声作用时间对液滴雾化概率的影响越显著。结果表明,超声波可以去除铝板表面作为结霜初始阶段的液滴,为冷表面有效抑霜提供了可能。  相似文献   

7.
同步辐射X射线荧光分析了安徽省4个地区的沼虾(Macrobrachium nipponesis)和米虾(Caridina denticulate sinensis)尾扇9个样品中重元紊含量;比较了7种不同水环境中沼虾的元素含量,显示出虾中元素含量随水环境的不同而改变,其中Mn/Fe或Cu/Zn元素的比值强烈地与水环境富营养污染程度相关。生活在同一水环境中米虾的重元素Br、Hg和Pb的富集量分别是沼虾的5.0倍、2.7倍和2.3倍。测量了老龄沼虾和成年沼虾的元素含量,发现老龄沼虾富集的Hg和Pb分别是成年虾的5倍和4倍,而Cu和Zn的含量却降低到成年虾的1/8和1/2。  相似文献   

8.
超声波强化超滤过程   总被引:5,自引:0,他引:5       下载免费PDF全文
陈健  肖凯军  郭祀远  李琳 《应用声学》2002,21(5):45-48,39
本文综述了超声波强化超滤的实验方法,超声波对越滤膜结构的影响及超声波强化清洗超滤膜等方面的研究进展,论述了超声波强化超滤的作用机理,声冲流和空化作用在超声波强化超滤中起到主要作用。  相似文献   

9.
张志彬  杨学友 《物理》1997,26(9):547-552
论述了超声波微电机的工作原理,给出了其振动模式和组合,分析了行波式超声波微电机定子表面的椭圆运动轨迹,给出了一些性能测试曲线,论述了超声波微电机的一些特点,并介绍了它的一些实际应用。  相似文献   

10.
超声波强化膜分离的研究进展   总被引:4,自引:0,他引:4       下载免费PDF全文
阎杰  丘泰球 《应用声学》2003,22(5):45-48
本文综述了超声波强化膜分离的机理,国内外超声波强化膜分离的研究现状以及影响超声波强化膜分离的因素(如声场参数、操作参数、料液性质等);同时评述了该技术存在的问题。现有的研究成果表明:如何在利用超声波提高膜分离效率的同时,减小超声波对有机溶质及膜稳定性的影响,应是近期的研究重点。  相似文献   

11.
ABSTRACT

We focused on food additives that enhance the effect of high hydrostatic pressure (HHP) treatment for microbial inactivation. We previously isolated Saccharomyces cerevisiae ultraviolet (UV) mutant strain a1210H12 that does not cause a growth delay under specific high pressure treatment conditions. We conceived that it is possible to screen effective food additives in a high-throughput manner by combining strain a1210H12 with a viable cell count method based on liquid culture, named high-throughput microbial pressure inactivation kinetics analysis system (HT-PIKAS). Here, we analyzed the synergistic effect between food additives and HHP treatment on inactivation of strain a1210H12 using HT-PIKAS. We calculated the inactivation rate in the condition of additive only, HHP treatment only and HHP treatment with additive. As a result, four compounds, benzoic acid, sorbic acid, adipic acid and caproic acid, showed high synergistic effects with HHP treatment and could be selected from more than 30 compounds as safe food additives.  相似文献   

12.
光谱分析技术以其简便、快速、高精度和无损测定等优越性,成为获取烟草和食品信息的重要手段.国内相关研究起步较晚,在近几年内,才涌现出了大量的有关烟草和食品研究报告,研究的范围也渐趋广泛,并综合分析了烟草成分测定、食品真伪鉴别、食品的定性鉴别的应用.因此,光谱分析技术的应用前景是非常广泛的,值得深入研究.  相似文献   

13.
仿刺参是具有极高经济价值的水产资源,是海水养殖产业的重要组成部分,研发出一种灵活、稳定、高效的仿刺参产地溯源方法对于水产养殖产业具有极强的现实意义。仿刺参主要有三种养殖方式,分别是底播增殖、圈养养殖和筏式养殖。不同产地采用不同的养殖方式,仿刺参的营养价值、药用价值和经济价值都存在着明显差异。不同产地初级生产者的构成不同,作为初级生产者的不同藻类与浮游生物体内的脂肪酸特征也各不相同,通过食物链的传递,不同产地的仿刺参具有了不同的脂肪酸特征。气相色谱指纹图谱法是一种快速准确地食品产地溯源技术,碳稳定同位素质谱法不仅可以鉴别产地还可以区分出食品的营养价值。采集9个最具代表性产地的仿刺参样品,先利用Folch法对样品进行总脂提取,再通过气相色谱仪测定出各种脂肪酸的种类及其相对含量;最后使用稳定同位素质谱仪测定出每种脂肪酸各自的碳稳定同位素组成数据。使用单因素方差分析法对脂肪酸相对含量和脂肪酸碳稳定同位素组成数据进行显著性检验,各筛选出17种脂肪酸数据作为两个模型的输入。主成分分析(PCA)法可以降低数据的维度,聚合不同种脂肪酸数据的溯源特征,提高产地溯源的精度。支持向量机(SVM)是一种以结构化风险最小为目标的分类识别算法,具有优秀的泛化能力。研究结果表明,不同产地仿刺参的脂肪酸相对含量和脂肪酸碳稳定同位素组成数据存在明显差异。通过主成分变换后,脂肪酸数据的聚类特征更加明显,运用随机交叉验证法确定前6个主成分作为两个支持向量机分类器的输入。采用基于遗传交叉因子改进的粒子群优化算法(GPSO),以粒子不同K值各100次交叉验证的平均准确率作为其适应度,寻找支持向量机分类器模型的最优参数组合。最终计算得到脂肪酸相对含量产地溯源模型的最优参数组合为σ=6.247 599和C=14.313 042,平均准确率为79.49%;脂肪酸碳稳定同位素组成产地溯源模型的最优参数组合为σ=7.626 194和C=2.193 410,平均准确率为98.33%。对比交叉验证的结果,脂肪酸碳稳定同位素组成产地溯源模型具有更高的准确率和更强的泛化性能。在两个模型的识别结果不一致时,采用脂肪酸碳稳定同位素组成模型的识别结果。将实验室检测与互联网技术进行整合,构建了仿刺参产地溯源在线系统。实现了“互联网+产地溯源”的一体化溯源模式,为进一步开展食品产地溯源研究提供了科学依据和技术支撑。  相似文献   

14.
激光诱导荧光光度法测定食品中的锌   总被引:3,自引:0,他引:3  
本文利用自行组装的激光诱导荧光 CCD阵列检测器 计算机联用装置 ,建立了一种测定食品中锌的灵敏方法。在乙酸 乙酸铵 ( pH =4 )缓冲溶液中 ,Zn(Ⅱ )与SCN、罗丹明B(RhB)反应生成Zn SCN RhB配合物 ,经乙醚萃取后 ,以YAG激光二倍频 5 32nm为激发波长 ,在 5 80nm处测定荧光强度 ,优化了反应及食品样品的处理条件 ,用于食品试样中锌的测定 ,获得了满意的结果 ,方法检出限 4ng/mL ,加标回收率90 0~ 1 1 0 0 % ,相对标准偏差为 2 0~ 9 7%。  相似文献   

15.
《Ultrasonics sonochemistry》2014,21(6):2112-2116
In food industry, conventional methodologies such as grinding, mixing, and heat treatment are used for food processing and preservation. These processes have been well studied for many centuries and used in the conversion of raw food materials to consumable food products. This report is dedicated to the application of a cost-efficient method of energy transfer caused by acoustic cavitation effects in food processing, overall, having significant impacts on the development of relatively new area of food processing such as food sonochemistry.  相似文献   

16.
 食品中微生物是导致食品品质降低的重要因素之一,超高压作为一种灭菌方式已取得了显著的效果。介绍了超高压杀菌基本原理,着重分析了超高压对微生物细胞形态结构、代谢、遗传物质等造成的影响,并展望了超高压在食品工业中的应用前景。  相似文献   

17.
Innovative technologies for the pasteurization of food products have increased due to the global demand for higher-quality food products. In this regard, the current article aimed to provide an overview regarding the latest research on US application in the decontamination of fungi in food products and highlight the parameters influencing the effectiveness of this method. Therefore, the related article with inactivation of fungi and mycotoxins by ultrasound among last four years (2018–2021) by using terms such as 'mycotoxin,' 'inactivation,' 'ultrasound,' 'decontamination' among some international databases such as PubMed, Web of Science, Embase and Google Scholar“ was retrieved. Ultrasound (US) is considered a non-thermal decontamination method for food products. In US, the release of energy due to the acoustic phenomenon destroys microorganisms. This technology is advantageous as it is inexpensive, eco-friendly, and does not negatively affect food products' food structure and organoleptic properties. The influence of the US on food structure and organoleptic properties dramatically depends on the intensity and energy density applied In addition, it can preserve higher levels of ascorbic acid, lycopene, and chlorophyll in sonicated food products. The treatment conditions, including frequency, intensity, duration, temperature, and processing pressure, influence the effectiveness of decontamination. However, US displays synergistic or antagonistic effects on bacteria, yeasts, molds, and mycotoxins when combined with other types of decontamination methods such as chemical and thermal approaches. Thus, further research is needed to clarify these effects. Overall, the application of US methods in the food industry for decreasing the microbial content of food products during processing has been applied. However, the use of US with other techniques needs to be studied further.  相似文献   

18.
Fumonisins are a family of food-borne mycotoxins with a wide spectrum of toxicological activities, produced by Fusarium verticillioides. Twenty-eight fumonisin analogues have been characterised so far, which can be separated into four main groups, identified as fumonisin A, B, C and P, being fumonisin B the most widely occurring in maize and corn-based food. In this work, major and minor fumonisin analogues produced by F. verticillioides have been determined by the development of a suitable tandem mass spectrometry procedure for target compound identification and quantification. The method has been applied to the determination of the major fumonisins in culture media of F. verticillioides and in mouldy maize. In addition to the main fumonisins produced by F. verticillioides, also secondary compounds such as FB4, FB5, FAs and FCs have been detected in both fungal liquid cultures and contaminated maize samples. The use of this method for quantification of major and minor fumonisins may be useful for an exhaustive evaluation of their occurrence and toxicological relevance in food; moreover, it may be applied for a better definition of the fumonisin biosynthetic pathways in different growing media as well as in maize. Copyright ? 2012 John Wiley & Sons, Ltd.  相似文献   

19.
Raman spectroscopy is a novel method of food analysis and inspection. It is highly accurate, quick, and noninvasive. The investigation and monitoring of food processing is important because most of the foods humans eat today are processed in various ways. In this article, the use of Raman spectroscopy in food processes, such as fermentation, cooking, processed food manufacturing, and so on, are explored. The characteristics and difficulties of the Raman inspection of these processes are also discussed. According to the various research reports, Raman spectroscopy is a very powerful tool for monitoring these food processes in lab environments and is likely to see usage in situ in the future.  相似文献   

20.
Solid foods include fish, shrimp, shellfish, and other aquatic products, fruits, and vegetables. These products are commonly used for food freezing, cooling, and thawing. However, traditional freezing, cooling, and thawing of solid food technologies have limitations in quality, such as protein denaturation and water loss in food. Ultrasound-assisted technology has become a useful method in solid food processing due to improved preservation quality of solid food. This paper comprehensively reviews the mechanism and application of ultrasonic in solid food processing technology. Although the application of ultrasound-assisted ultrasound in solid food processing is relatively comprehensive, the energy saving of food cold processing is essential for practical application. This paper analyzes the optimization of ultrasonic in solid food processing, including orthogonal/multi-frequency technology and the combination of ultrasonic and other technologies, which provides new ideas for freezing, cooling, and thawing of solid food processing.  相似文献   

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