In this study,the separation and coalescence of oil-in-water emulsions are explored in an ultrasonic field using the lattice Boltzmann method.By simulating the propagation of ultrasonic waves,this study focuses on exa...In this study,the separation and coalescence of oil-in-water emulsions are explored in an ultrasonic field using the lattice Boltzmann method.By simulating the propagation of ultrasonic waves,this study focuses on examining the effects of acoustic wave frequency,the ratio of oil to water components,and the aspect ratio of the boundary on the emulsification and separation processes of oil-water mixtures.The following conclusions are drawn.①Frequency affects the speed of oil droplet separation,leading to an increase in droplet size over time.Larger droplets are found near the source,while smaller droplets are distributed throughout the wave web.②As the boundary aspect ratio increases,the emulsification efficiency of the droplets weakens,and the system takes longer to stabilize.③Emulsions with a higher component of oil can better resist acoustic waves.④At the same acoustic frequency,longer wavelength ultrasonic fields promote the formation of uniformly distributed,smaller oil droplets,which is beneficial to the storage of emulsions.These numerical simulation results offer insights for optimizing conditions for oil-in-water separation and serve as a numerical reference for the study of oil-in-water emulsion separation in ultrasonic environments.展开更多
目的探讨超声造影(contrast-enhancedultrasound,CEUS)评价颈动脉斑块易损性对脑卒中的预测价值。方法纳嘉兴市第一医院2020年5月至2022年5月收治的颈动脉斑块患者108例进行回顾性研究,均行CEUS检查,评估斑块易损性。根据患者是否发生...目的探讨超声造影(contrast-enhancedultrasound,CEUS)评价颈动脉斑块易损性对脑卒中的预测价值。方法纳嘉兴市第一医院2020年5月至2022年5月收治的颈动脉斑块患者108例进行回顾性研究,均行CEUS检查,评估斑块易损性。根据患者是否发生脑卒中,分成卒中组(n=51)、非卒中组(n=57),比较两组颈动脉斑块的CEUS特征,包括新生血管分级、灌注方向、主要增强部位。绘制受试者工作特征(receiver operating characteristic,ROC)曲线分析颈动脉斑块常规超声特征、CEUS特征对脑卒中的预测价值。结果卒中组平均斑块长度、厚度高于非卒中组,斑块狭窄程度≥50%、低回声为主的混合回声、斑块表面溃疡占比高于非卒中组(P<0.05)。卒中组0级、1级占比低于非卒中组,2级、3级占比高于非卒中组,且2级+3级总数占比高于非卒中组(P<0.05)。两组斑块内新生血管的灌注方向比较,差异无统计学意义(P>0.05)。卒中组斑块肩部增强占比高于非卒中组(P<0.05)。常规超声评估斑块易损预测脑卒中的曲线下面积(area under curve,AUC)为0.612,敏感度为62.75%,特异性为59.65%。CEUS评估斑块易损预测脑卒中的AUC为0.788,敏感度为80.39%,特异性为77.19%。结论CEUS可以通过评估患者的颈动脉斑块易损情况,对脑卒中发生风险进行预测,敏感度与特异性较理想。展开更多
针对目前基于格的身份基代理重加密方案存在的加/解密效率低和密文、密钥尺寸过长的问题,采用原像抽样和对偶加密技术,重新构造了一个基于格的身份基代理重加密方案。该方案采用原像抽样技术提取用户私钥,用对偶加密算法对消息进行加密...针对目前基于格的身份基代理重加密方案存在的加/解密效率低和密文、密钥尺寸过长的问题,采用原像抽样和对偶加密技术,重新构造了一个基于格的身份基代理重加密方案。该方案采用原像抽样技术提取用户私钥,用对偶加密算法对消息进行加密,利用代理重加密密钥进行重加密,并用用户的私钥进行解密。安全分析表明,在标准模型下,基于ring learning with errors困难假设,该方案满足IND-aID-CPA安全。效率分析表明,该方案可以有效缩短密文和密钥尺寸,提高加/解密效率。展开更多
基金the National Natural Science Foundation of China(Program Nos.12161058,61962051,and 12361096)the Science and Technology Plan Project of Qinghai Province-Applied Basic Research Plan(No.2023-ZJ-736)the Open Project of State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University(No.2021-ZZ-02).
文摘In this study,the separation and coalescence of oil-in-water emulsions are explored in an ultrasonic field using the lattice Boltzmann method.By simulating the propagation of ultrasonic waves,this study focuses on examining the effects of acoustic wave frequency,the ratio of oil to water components,and the aspect ratio of the boundary on the emulsification and separation processes of oil-water mixtures.The following conclusions are drawn.①Frequency affects the speed of oil droplet separation,leading to an increase in droplet size over time.Larger droplets are found near the source,while smaller droplets are distributed throughout the wave web.②As the boundary aspect ratio increases,the emulsification efficiency of the droplets weakens,and the system takes longer to stabilize.③Emulsions with a higher component of oil can better resist acoustic waves.④At the same acoustic frequency,longer wavelength ultrasonic fields promote the formation of uniformly distributed,smaller oil droplets,which is beneficial to the storage of emulsions.These numerical simulation results offer insights for optimizing conditions for oil-in-water separation and serve as a numerical reference for the study of oil-in-water emulsion separation in ultrasonic environments.
文摘目的探讨超声造影(contrast-enhancedultrasound,CEUS)评价颈动脉斑块易损性对脑卒中的预测价值。方法纳嘉兴市第一医院2020年5月至2022年5月收治的颈动脉斑块患者108例进行回顾性研究,均行CEUS检查,评估斑块易损性。根据患者是否发生脑卒中,分成卒中组(n=51)、非卒中组(n=57),比较两组颈动脉斑块的CEUS特征,包括新生血管分级、灌注方向、主要增强部位。绘制受试者工作特征(receiver operating characteristic,ROC)曲线分析颈动脉斑块常规超声特征、CEUS特征对脑卒中的预测价值。结果卒中组平均斑块长度、厚度高于非卒中组,斑块狭窄程度≥50%、低回声为主的混合回声、斑块表面溃疡占比高于非卒中组(P<0.05)。卒中组0级、1级占比低于非卒中组,2级、3级占比高于非卒中组,且2级+3级总数占比高于非卒中组(P<0.05)。两组斑块内新生血管的灌注方向比较,差异无统计学意义(P>0.05)。卒中组斑块肩部增强占比高于非卒中组(P<0.05)。常规超声评估斑块易损预测脑卒中的曲线下面积(area under curve,AUC)为0.612,敏感度为62.75%,特异性为59.65%。CEUS评估斑块易损预测脑卒中的AUC为0.788,敏感度为80.39%,特异性为77.19%。结论CEUS可以通过评估患者的颈动脉斑块易损情况,对脑卒中发生风险进行预测,敏感度与特异性较理想。
文摘针对目前基于格的身份基代理重加密方案存在的加/解密效率低和密文、密钥尺寸过长的问题,采用原像抽样和对偶加密技术,重新构造了一个基于格的身份基代理重加密方案。该方案采用原像抽样技术提取用户私钥,用对偶加密算法对消息进行加密,利用代理重加密密钥进行重加密,并用用户的私钥进行解密。安全分析表明,在标准模型下,基于ring learning with errors困难假设,该方案满足IND-aID-CPA安全。效率分析表明,该方案可以有效缩短密文和密钥尺寸,提高加/解密效率。
