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Fluorescent molecular rotors (MRs) are compounds whose emission is modulated by segmental mobility; photoexcitation generates a locally excited (LE), planar state that can relax either by radiative decay (emission of a photon) or by formation of a twisted intramolecular charge transfer (TICT) state that can relax nonradiatively due to internal rotation. If the local environment around the probe allows for rapid internal rotation in the excited state, fast non-radiative decay can either effectively quench the fluorescence or generate a second, red-shifted emission band. Conversely, any environmental restriction to twisting in the excited state due to free volume, crowding or viscosity, slows rotational relaxation and promotes fluorescence emission from the LE state. The environmental sensitivity of MRs has been exploited extensively in biological applications to sense microviscosity in biofluids, the stability and physical state of biomembranes, and conformational changes in macromolecules. The application of MRs in food research, however, has been only marginally explored. In this review, we summarize the main characteristics of fluorescent MRs, their current applications in biological research and their current and potential applications as sensors of physical properties in food science and engineering.  相似文献   

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大豆组织蛋白丸子配方的优化研究   总被引:1,自引:0,他引:1  
采用大豆组织蛋白为主料制作丸子,既能提高产品的营养价值,又能降低生产成本。通过单纯形格子法对大豆组织蛋白丸子配方进行研究分析,并利用质构仪来测定丸子的质地特征。结果表明:组织蛋白对丸子的弹性影响最大,大豆分离蛋白在咀嚼性、回复性和感官评定都起着重要作用。综合考虑成本与各因素指标,确定组织蛋白丸子配方为猪肉14.9%、大豆组织蛋白59.6%,大豆分离蛋白5%、变性淀粉13.4%、豆油7.1%,在该条件下制得丸子的弹性、咀嚼性、回复性和感官评定分别为0.921、1469.323、0.510和21.62,与预测值相对误差均在±1%以内,说明利用该方法建立的模型进行预测生产是可行的。  相似文献   

4.
《Journal of dairy science》2022,105(5):4534-4546
Up until now, bovine fetometry has been entirely based on 2-dimensional ultrasonography. Fetal size is estimated by several linear measurements such as crown-rump length (CRL). However, the advent of 3-dimensional ultrasonography (3D-US) provides in vivo access to the volumes of the fetus and its amniotic sac. The objective of this preliminary observational study was to determine the variability of conceptus-related volumes using transrectal 3D-US in dairy cows and to identify factors affecting them. Furthermore, relationships between the gained measurements and calf birth weight were investigated. In total, 315 Simmental and Holstein-Friesian dairy cows were transrectally examined at d 42 after breeding using a portable ultrasound device (Voluson I, GE Healthcare). Gestational volumes including fetal volume (FV) and amniotic sac volume (ASV) were determined with the software tool VOCAL (Virtual Organ Computer-Aided Analysis, GE Healthcare), whereas amniotic fluid volume (AFV) values were derived from the subtraction of FV from ASV. The CRL was determined by means of 3-dimensional data. The mean values and standard deviations for FV, ASV, AFV, and CRL were 1.47 ± 0.25 cm3, 5.86 ± 1.22 cm3, 4.38 ± 1.02 cm3, and 2.38 ± 0.18 cm, respectively. All gestational volumes and CRL values were affected by breed. In Simmental cattle, larger concepti were observed compared with pregnancies derived from Holstein-Friesian animals. Parity affected only ASV and AFV, with heifers showing greater values than lactating cows. The CRL was positively associated with milk protein content. It was not possible to predict calf weight at birth by using FV, ASV, or AFV; however, tendencies were found for ASV and AFV. The present study was the first to adopt 3D-US volumetry to assess early pregnancy development in dairy cattle. Our results showed that this method could be used successfully to identify minor variations in conceptus growth.  相似文献   

5.
圆柱滚子是滚柱轴承的重要部件,其加工质量影响着滚柱轴承的品质。传统圆柱滚子加工方法主要有无心磨削、无心磨削和超精加工等。随着滚子材料的更新和加工质量提高,新型的加工方法应运而生。文章对圆柱滚子的加工方法进行分析和比较,指出高效率、高精度以及高适用性是滚子加工的技术发展趋势。  相似文献   

6.
A mixture design was used to evaluate the effect of replacing (0 to 100%) wheat flour (WF) with wholegrain azuki bean (WABF) and rice (RF) flours on the biscuits quality. High proportions of WABF increased diameter and decreased thickness, whereas WF affected inversely and RF intermediate. The WF biscuit specific volume was 17% greater than that of the dough, and the WABF and RF biscuits were 5 and 13% smaller, respectively. The WABF biscuit hardness was 26.25 N, close to WF (28.14 N), and higher than RF (7.6 N). The WABF increased the colour difference (ΔE) values for biscuits by up to 22.19 and the RF by 1.87. Peak viscosity, breakdown and setback of mixture flours showed positive correlations with the dough hardness and L*, a*, b* and Aw of biscuits and negatively with the radial expansion index and ΔE. The highest global desirability was for biscuits without WF, regardless of crust colour.  相似文献   

7.
李秋梅  武道吉  孙梅 《纸和造纸》2007,26(Z1):62-66
从造纸中段废水的处理现状出发,对造纸中段废水深度处理的必要性和紧迫性进行了总结,并以广泛研究和实际应用的废水深度处理方法为基础,对它们应用于中段废水深度处理的可行性进行分析。对于中段水的深度处理,如果采取单一的处理方法,物化法存在着成本高、吸附剂再生困难、污泥量大等缺点,生物法难于进一步降低COD,生态法受土地等条件的制约,有着应用的局限性。只有通过方法的联合,优势互补,才能做到经济性和实用性的统一。  相似文献   

8.
Using weaving technology, possible manipulations can be done so as to derive maximum advantage from the reinforcements towards desired mechanical properties of the composites. Thus with different sets of weaving parameters and tow linear densities, an attempt has been made to investigate tensile, impact and knife penetration performance of different stuffer layers and fibre volume fractions of 3D orthogonal and interlock E-glass fabrics as reinforcements for composite applications. The tensile properties were effectively influenced by warp tow crimp%, number of stuffer tows per unit width of the fabric and fabric assistance. The tow linear density, fabric sett and the number of cross over points play a determining role towards impact energy absorption capacity. The fabric sett along with tow linear densities also play a vital role towards peak energy during knife penetration test. The number of cross over points were found to be least important in the knife penetration results analysis.  相似文献   

9.
贵州茅台酒首次总结的回顾   总被引:1,自引:0,他引:1  
首次茅台酒生产工艺总结是1959~1960年,为国家重大科研课题。该工艺的总结不仅促进了茅台酒自身的发展,而且促进了全国白酒行业的科技进步和技术创新。采用现场跟踪、生产纪录、取样分析、微生物检测和综合研究方法,确定了生产工艺,完善了操作方法,保证了产品质量,提高出酒率10%以上。并认定茅台大曲为细菌曲,制订了入库酒和出厂酒的理化指标。(庞晓)  相似文献   

10.
微胶囊技术是21世纪重点研究开发的高新技术之一,系将固、液、气态物质包埋到半透性或封闭的微小胶囊内,使内容物在特定的条件下以可控的速度进行释放的技术。该技术不仅可增加产品的附加值,亦可获得具有优良特性的新原料,已成功的在食品、化工、医药、生物技术等许多领域获得应用。近年来,该技术广泛应用于食品添加剂工业中,其独特的功能使许多传统工艺无法解决的难题得以解决,使食品添加剂工业得到长足的发展。本文介绍了微胶囊技术中芯材、壁材的种类及选用,常用微胶囊化方法;对该技术的主要功能、特点、研究进展及其在食品添加剂工业中的应用概况做出综述;指出了该技术目前存在的问题及其今后发展的方向,以期促进相关的研究工作。  相似文献   

11.
非齐次Bernoulli方程的一个可积定理   总被引:2,自引:0,他引:2  
由著名的Bernoulli微分方程引进了非齐次Bernoulli方程的概念。在一定的条件下通过函数的线性拓扑变换将非齐次Bernoulli方程化为变量分离方程,得到一个新的、实用的可积定理。熟知的一阶线性微分方程、Bernoulli方程及著名的Riccati方程、Appel方程的一些经典的可积性结果都是这定理的特例,从而扩大了常微分方程封闭求积的范围。  相似文献   

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