双凝胶体系的理化特性是影响其在食品加工中应用的重要因素。本研究通过调控乳清分离蛋白(whey protein isolate,WPI)水凝胶pH与两相比例,制备具有不同形态结构的双凝胶体系,并分析其理化特性及相关机制。结果表明,水凝胶pH与油水相比...双凝胶体系的理化特性是影响其在食品加工中应用的重要因素。本研究通过调控乳清分离蛋白(whey protein isolate,WPI)水凝胶pH与两相比例,制备具有不同形态结构的双凝胶体系,并分析其理化特性及相关机制。结果表明,水凝胶pH与油水相比例可协同影响双凝胶体系的凝胶状态、涂抹特性和挤压流动性,当油凝胶含量增加时,可改善双凝胶体系的凝胶状态,并降低其涂抹性和流动性,而pH则可通过影响水凝胶特性及油/水相互作用而改变体系的表观特性。另外在WPI等电点附近,双凝胶体系具有较差的油水结合能力,但油水相比例的增加有利于提高其持水能力。双凝胶体系微观结构显示,水凝胶pH和油水相比例会影响油相中晶体的形态,且在pH6.0下,体系呈现油包水型结构,而其他p H条件下,体系则呈现复杂的双连续凝胶结构,且在高油水相比例下易于形成油滴聚集而影响体系的网络结构。双凝胶体系的质构和流变特性分析则表明,整体上油/水相比例的增加有利于其质构的改善及凝胶模量和表观粘度增加,当pH为7.0时,双凝胶体系具有较好的质构与流变特性,而在pH3.0下则表现出较好的结构恢复性。红外光谱和晶体分析则证实了双凝胶体系的两相之间主要以氢键为主,晶体结构主要为α、β′晶型。上述研究有助于利用水凝胶p H和油水相比例来实现对双凝胶体系理化特性的调控,以使其适用于具有不同感官特性的产品。展开更多
目的探究超声联合神经刺激仪定位腰丛及坐骨神经阻滞在椎管内麻醉禁忌证患者中的应用效果。方法选取本院2019年6月至2019年10月收治72例的下肢手术患者作为研究对象,随机分为观察组与对照组,各36例。对照组采用全身麻醉,观察组采用超声...目的探究超声联合神经刺激仪定位腰丛及坐骨神经阻滞在椎管内麻醉禁忌证患者中的应用效果。方法选取本院2019年6月至2019年10月收治72例的下肢手术患者作为研究对象,随机分为观察组与对照组,各36例。对照组采用全身麻醉,观察组采用超声联合神经刺激仪定位并麻醉,对比两组患者术后不良反应及疗效。结果观察组患者在阻滞前、阻滞后10 min及30 min MAP及HR比较差异无统计学意义,对照组在阻滞后10 min与30 min HR及MAP均明显低于阻滞前(P<0.05);观察组不良反应发生率(8.33%)明显低于对照组(36.11%)(P<0.05);观察组阻滞完成时间、麻醉起效时间均明显短于对照组(P<0.05),镇痛维持时间明显长于对照组(P<0.05)。结论超声联合神经刺激仪定位腰丛及坐骨神经阻滞效果显著,生理功能干扰小,可在短时间内完成阻滞,快速起效,且镇痛持续时间长,是椎管内麻醉禁忌证患者可用的有效麻醉方法。展开更多
To solve the precision and reliability problem of various machinery equipments and military vehicles, some military organisations, the industrial sector and the academia at home and abroad begin to pay attention to th...To solve the precision and reliability problem of various machinery equipments and military vehicles, some military organisations, the industrial sector and the academia at home and abroad begin to pay attention to the statistical distribution of machining dimensions, material properties and service loads, and the system reliability optimization design with constraints and reliability optimization design of various mechanical parts is studied in this way. However, the above researches focus on solving the strength and the life problem, and no studies have been done on the discrete degree and discrete pattern of other performance indicators. The concept of using a random vector to describe the mechanical parts performance indicators is presented; characteristics between the value of the vector variance matrix determinant and the sum of the diagonal covariance matrix in describing the performance indicators of vector dispersion are studied and compared. A clutch diaphragm spring is set as an example, the geometric dimension indicator is described with random vector, and the applicability of using variance matrix determinant and variance matrix trace of geometric dimension vector to describe discrete degree of random vector is studied by using Monte-Carlo simulation method and component discrete degree perturbation method. Also, the effects of different components of diaphragm spring geometric dimension vector on the value of covariance matrix determinant and the sum of covariance matrix diagonal of diaphragm spring performance indicators vector are analyzed. The present study shows that the impacts of the dispersion of diaphragm spring cone angle on every performance dispersion are all ranked first, and far exceed that of other dimension dispersion. So it must be strictly controlled in the production process. The result of the research work provides a reference for the design of diaphragm spring, and also it presents a proper method for researching the performance of other mechanical parts.展开更多
文摘双凝胶体系的理化特性是影响其在食品加工中应用的重要因素。本研究通过调控乳清分离蛋白(whey protein isolate,WPI)水凝胶pH与两相比例,制备具有不同形态结构的双凝胶体系,并分析其理化特性及相关机制。结果表明,水凝胶pH与油水相比例可协同影响双凝胶体系的凝胶状态、涂抹特性和挤压流动性,当油凝胶含量增加时,可改善双凝胶体系的凝胶状态,并降低其涂抹性和流动性,而pH则可通过影响水凝胶特性及油/水相互作用而改变体系的表观特性。另外在WPI等电点附近,双凝胶体系具有较差的油水结合能力,但油水相比例的增加有利于提高其持水能力。双凝胶体系微观结构显示,水凝胶pH和油水相比例会影响油相中晶体的形态,且在pH6.0下,体系呈现油包水型结构,而其他p H条件下,体系则呈现复杂的双连续凝胶结构,且在高油水相比例下易于形成油滴聚集而影响体系的网络结构。双凝胶体系的质构和流变特性分析则表明,整体上油/水相比例的增加有利于其质构的改善及凝胶模量和表观粘度增加,当pH为7.0时,双凝胶体系具有较好的质构与流变特性,而在pH3.0下则表现出较好的结构恢复性。红外光谱和晶体分析则证实了双凝胶体系的两相之间主要以氢键为主,晶体结构主要为α、β′晶型。上述研究有助于利用水凝胶p H和油水相比例来实现对双凝胶体系理化特性的调控,以使其适用于具有不同感官特性的产品。
文摘目的探究超声联合神经刺激仪定位腰丛及坐骨神经阻滞在椎管内麻醉禁忌证患者中的应用效果。方法选取本院2019年6月至2019年10月收治72例的下肢手术患者作为研究对象,随机分为观察组与对照组,各36例。对照组采用全身麻醉,观察组采用超声联合神经刺激仪定位并麻醉,对比两组患者术后不良反应及疗效。结果观察组患者在阻滞前、阻滞后10 min及30 min MAP及HR比较差异无统计学意义,对照组在阻滞后10 min与30 min HR及MAP均明显低于阻滞前(P<0.05);观察组不良反应发生率(8.33%)明显低于对照组(36.11%)(P<0.05);观察组阻滞完成时间、麻醉起效时间均明显短于对照组(P<0.05),镇痛维持时间明显长于对照组(P<0.05)。结论超声联合神经刺激仪定位腰丛及坐骨神经阻滞效果显著,生理功能干扰小,可在短时间内完成阻滞,快速起效,且镇痛持续时间长,是椎管内麻醉禁忌证患者可用的有效麻醉方法。
文摘To solve the precision and reliability problem of various machinery equipments and military vehicles, some military organisations, the industrial sector and the academia at home and abroad begin to pay attention to the statistical distribution of machining dimensions, material properties and service loads, and the system reliability optimization design with constraints and reliability optimization design of various mechanical parts is studied in this way. However, the above researches focus on solving the strength and the life problem, and no studies have been done on the discrete degree and discrete pattern of other performance indicators. The concept of using a random vector to describe the mechanical parts performance indicators is presented; characteristics between the value of the vector variance matrix determinant and the sum of the diagonal covariance matrix in describing the performance indicators of vector dispersion are studied and compared. A clutch diaphragm spring is set as an example, the geometric dimension indicator is described with random vector, and the applicability of using variance matrix determinant and variance matrix trace of geometric dimension vector to describe discrete degree of random vector is studied by using Monte-Carlo simulation method and component discrete degree perturbation method. Also, the effects of different components of diaphragm spring geometric dimension vector on the value of covariance matrix determinant and the sum of covariance matrix diagonal of diaphragm spring performance indicators vector are analyzed. The present study shows that the impacts of the dispersion of diaphragm spring cone angle on every performance dispersion are all ranked first, and far exceed that of other dimension dispersion. So it must be strictly controlled in the production process. The result of the research work provides a reference for the design of diaphragm spring, and also it presents a proper method for researching the performance of other mechanical parts.
