The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial....The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.Mixing intensification encompasses innovative methods and tools that address the limitations of inadequate mixing within reactors,enabling efficient reaction scaling and boosting the productivity of industrial processes.This review provides a concise introduction to the fundamentals of multiphase mixing,followed by case studies highlighting the application of mixing intensification in the production of energy-storage materials,advanced optical materials,and nanopesticides.These examples illustrate the significance of theoretical analysis in informing and advancing engineering practices within the chemical industry.We also explore the challenges and opportunities in this field,offering insights based on our current understanding.展开更多
The coupled CFD-E-model for multiphase micro-mixing was developed,and used to predict the micro-mixing effects on the parallel competing chemical reactions in semi-batch gas–liquid and solid–liquid stirred tanks.Bas...The coupled CFD-E-model for multiphase micro-mixing was developed,and used to predict the micro-mixing effects on the parallel competing chemical reactions in semi-batch gas–liquid and solid–liquid stirred tanks.Based on the multiphase macro-flow field,the key parameters of the micro-mixing E-model were obtained with solving the Reynolds-averaged transport equations of mixture fraction and its variance at low computational costs.Compared with experimental data,the multiphase numerical method shows the satisfactory predicting ability.For the gas–liquid system,the segregated reaction zone is mainly near the feed point,and shrinks to the exit of feed-pipe when the feed position is closer to the impeller.Besides,surface feed requires more time to completely exhaust the added H+solution than that of impeller region feed at the same operating condition.For the solid–liquid system,when the solid suspension cloud is formed at high solid holdups,the flow velocity in the clear liquid layer above the cloud is notably reduced and the reactions proceed slowly in this almost stagnant zone.Therefore,the segregation index in this case is larger than that in the dilute solid–liquid system.展开更多
Laminar mixing in the stirred tank is widely encountered in chemical and biological industries.Isolated mixing regions(IMRs)usually exist when the fluid medium has high viscosity,which are not conducive to mixing.In t...Laminar mixing in the stirred tank is widely encountered in chemical and biological industries.Isolated mixing regions(IMRs)usually exist when the fluid medium has high viscosity,which are not conducive to mixing.In this work,the researches on IMRs,enhancement of laminar mixing and the phenomenon of particle clustering within IMRs are reviewed.For most studies,the aim is to destroy IMRs and improve the chaotic mixing.To this end,the mechanism of chaotic mixing and the structure of IMRs were well investigated.The methods developed to destroy IMRs include off-centered agitation,dynamic mixing protocol,special designs of impellers,baffles,etc.In addition,the methods to characterize the shape and size of IMRs as well as mixing effect by experiments and simulations are summarized.However,IMRs are not always nuisance,and it may be necessary in some situations.Finally,the present engineering applications are summarized,and the prospect of the future application is predicted.For example,particle clustering will form in the co-existing system of chaotic mixing and IMRs,which can be used for solid–liquid separation and recovery of particles from high viscosity fluid.展开更多
世界卫生组织(World Health Organization,WHO)发布的关于口腔卫生的报道中提出:颌面及唇腭裂是口腔颌面部最常见的先天性发育畸形,全球患病率为1/1500~1/1000(颌面及唇腭裂患者/被观察总人口),我国唇腭裂的发病率约1.82‰[1],术后由于...世界卫生组织(World Health Organization,WHO)发布的关于口腔卫生的报道中提出:颌面及唇腭裂是口腔颌面部最常见的先天性发育畸形,全球患病率为1/1500~1/1000(颌面及唇腭裂患者/被观察总人口),我国唇腭裂的发病率约1.82‰[1],术后由于腭咽闭合不全(velopharyngeal insufficiency,VPI)导致语音障碍的发病率为25.00%~50.00%,神经生理调控障碍中因中枢神经系统异常出现运动失调型语音障碍的发生率为15.00%[2],而合并语言障碍的发生率为28.00%[3],唇腭裂儿童更容易被诊断为精神、智力、语言障碍。研究显示腭裂患者中88.38%存在中重度听力损失,且未经治疗的中耳炎是导致听力损失的重要因素[4]。展开更多
Microsurgical longitudinal intussusception vasoepididymostomy （LIVE） has been widely used to treat epididymal obstructive azoospermia since 2004. Although the deferential vasculature plays an important role in suppl...Microsurgical longitudinal intussusception vasoepididymostomy （LIVE） has been widely used to treat epididymal obstructive azoospermia since 2004. Although the deferential vasculature plays an important role in supplying blood to the testis and epididymis, little attention has been paid to the potential benefits of sparing the deferential vessels during the anastomosis in LIVE. This study aimed to evaluate the efficacy and safety of deferential vessel-sparing LIVE in humans. From December 2013 to December 2015, 69 azoospermic men with epididymal obstruction due to a genital infection, trauma, or idiopathic factors underwent deferential vessel-sparing LIVE in the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China. The outcomes of these patients were analyzed retrospectively. The mean age was 31.1 years for men and 28.3 years for their partners. Fifty-nine （85.5%, 59/69） men were followed up after surgery for approximately 16 months. Patency was noted and confirmed by semen analysis （〉10 000 sperm/ml） in 83.1% （49159） of men. The natural pregnancy rate was 40.7% （24/59） by the end of the study, with 87.5% （21124） of these natural pregnancies achieved within 12 months after surgery. No severe adverse events or complications were observed. In this study, we present a novel technique for sparing the deferential vessels during LIVE. The preliminary outcomes show this technique to be safe with favorable patency and pregnancy rates.展开更多
The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][...The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.展开更多
因高能量密度和高能量转换效率,锂离子电池已被广泛应用于便携式电子设备和电动交通中。富锂层状结构氧化物以高达300 m Ah·g^-1的可逆容量成为能量密度350 Wh·kg^-1及以上动力锂离子电池的重要候选正极材料。但是,欲使这类...因高能量密度和高能量转换效率,锂离子电池已被广泛应用于便携式电子设备和电动交通中。富锂层状结构氧化物以高达300 m Ah·g^-1的可逆容量成为能量密度350 Wh·kg^-1及以上动力锂离子电池的重要候选正极材料。但是,欲使这类材料获得实际应用,就必须解决循环过程中结构衰退带来的一系列问题。本文重点介绍近几年来笔者所领导的研究组通过元素筛选实现材料的表面和体相掺杂,通过全新的结构设计稳定材料结构和性能方面的努力。同时,为使读者对国内外重要研究组在相关方面的研究进展也有所了解,我们也将从元素替代、结构一体化表面修饰(包括多层表面修饰和浓度梯度材料)、表面包覆和表面掺杂等方面介绍他们的重要研究成果。最后,将对该类材料的未来发展方向作出展望并给出我们的一些思考。展开更多
Membrane fouling is the primary resistance to the continuous production of stirred membrane reactors.This work presents a laser-enhanced high-magnification telecentric imaging system(LEHTIS),which uses a high-magnific...Membrane fouling is the primary resistance to the continuous production of stirred membrane reactors.This work presents a laser-enhanced high-magnification telecentric imaging system(LEHTIS),which uses a high-magnification telecentric lens and laser-enhanced illumination to invasively capture the motion of particles on the membrane surface or near the membrane.The problems of working distance and particle interference in the stirred membrane reactor are solved to achieve the purpose of in-situ monitoring of membrane fouling.This method is suitable for high flow rates,high solid holdup,and small particle size systems,and the dynamic motion and accumulation of particles are preliminarily analyzed.It shows that the accumulation and desorption of particles on the membrane surface are related to the physical properties of the membrane surface.There is an intermittent rotational movement in the flow field near the membrane,and it tends to stabilize over time.The filtration process can be assessed by monitoring changes in the overall velocity and acceleration of particles near the membrane.The analysis of forces acting on individual particles is compared and validated with the force balance model to correct and accurately apply it to stirred membrane reactors.The development of LEHTIS provides an effective tool for in-situ monitoring of membrane fouling and optimizing the stirred membrane reactors for industrial applications.展开更多
基金supported by the National Natural Science Foundation of China(22288102,22035007,and 22122815)。
文摘The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.Mixing intensification encompasses innovative methods and tools that address the limitations of inadequate mixing within reactors,enabling efficient reaction scaling and boosting the productivity of industrial processes.This review provides a concise introduction to the fundamentals of multiphase mixing,followed by case studies highlighting the application of mixing intensification in the production of energy-storage materials,advanced optical materials,and nanopesticides.These examples illustrate the significance of theoretical analysis in informing and advancing engineering practices within the chemical industry.We also explore the challenges and opportunities in this field,offering insights based on our current understanding.
基金supported by the National Key Research and Development Program(2016YFB0301702)the National Natural Science Foundation of China(21808221,21776282,21938009)+3 种基金Major Research Plan of NSFC(91934301)the Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-JSC030)the Key Research Program of Nanjing IPE Institute of Green Manufacturing Industry(No.E0010719)the Youth Innovation Promotion Association CAS。
文摘The coupled CFD-E-model for multiphase micro-mixing was developed,and used to predict the micro-mixing effects on the parallel competing chemical reactions in semi-batch gas–liquid and solid–liquid stirred tanks.Based on the multiphase macro-flow field,the key parameters of the micro-mixing E-model were obtained with solving the Reynolds-averaged transport equations of mixture fraction and its variance at low computational costs.Compared with experimental data,the multiphase numerical method shows the satisfactory predicting ability.For the gas–liquid system,the segregated reaction zone is mainly near the feed point,and shrinks to the exit of feed-pipe when the feed position is closer to the impeller.Besides,surface feed requires more time to completely exhaust the added H+solution than that of impeller region feed at the same operating condition.For the solid–liquid system,when the solid suspension cloud is formed at high solid holdups,the flow velocity in the clear liquid layer above the cloud is notably reduced and the reactions proceed slowly in this almost stagnant zone.Therefore,the segregation index in this case is larger than that in the dilute solid–liquid system.
基金supports from National Key Research and Develop-ment Program(2020YFA0906804)the National Natural Science Foundation of China(21776282,21978296 and 22078229)+4 种基金the NSFC Key Program(21938009)major project(91934301)the National Key R&D Program of China(2019YFC1905805)Chemistry and Chemical Engineering Guangdong Laboratory Shantou(1922006)Innovation Academy for Green Manufacture,Chinese Academy of Sciences(IAGM2020C06)。
文摘Laminar mixing in the stirred tank is widely encountered in chemical and biological industries.Isolated mixing regions(IMRs)usually exist when the fluid medium has high viscosity,which are not conducive to mixing.In this work,the researches on IMRs,enhancement of laminar mixing and the phenomenon of particle clustering within IMRs are reviewed.For most studies,the aim is to destroy IMRs and improve the chaotic mixing.To this end,the mechanism of chaotic mixing and the structure of IMRs were well investigated.The methods developed to destroy IMRs include off-centered agitation,dynamic mixing protocol,special designs of impellers,baffles,etc.In addition,the methods to characterize the shape and size of IMRs as well as mixing effect by experiments and simulations are summarized.However,IMRs are not always nuisance,and it may be necessary in some situations.Finally,the present engineering applications are summarized,and the prospect of the future application is predicted.For example,particle clustering will form in the co-existing system of chaotic mixing and IMRs,which can be used for solid–liquid separation and recovery of particles from high viscosity fluid.
文摘世界卫生组织(World Health Organization,WHO)发布的关于口腔卫生的报道中提出:颌面及唇腭裂是口腔颌面部最常见的先天性发育畸形,全球患病率为1/1500~1/1000(颌面及唇腭裂患者/被观察总人口),我国唇腭裂的发病率约1.82‰[1],术后由于腭咽闭合不全(velopharyngeal insufficiency,VPI)导致语音障碍的发病率为25.00%~50.00%,神经生理调控障碍中因中枢神经系统异常出现运动失调型语音障碍的发生率为15.00%[2],而合并语言障碍的发生率为28.00%[3],唇腭裂儿童更容易被诊断为精神、智力、语言障碍。研究显示腭裂患者中88.38%存在中重度听力损失,且未经治疗的中耳炎是导致听力损失的重要因素[4]。
基金This work was supported by grants from the National Natural Science Foundation of China （No. 81172432, 81302223, 81671449, and 81471449）, the Guangdong Province Natural Science Foundation （No. 2015A030313141 and 2015A030313013）, the Scientific and Technical Project of Guangdong Province （No. 2016B030230001, 2013B051000021, 2016A040403113, 2016A020214004, and 2016A020218007）, and the Scientific and Technical Project of Guangzhou city （No. 2013J4500010 and 201604020189）.
文摘Microsurgical longitudinal intussusception vasoepididymostomy （LIVE） has been widely used to treat epididymal obstructive azoospermia since 2004. Although the deferential vasculature plays an important role in supplying blood to the testis and epididymis, little attention has been paid to the potential benefits of sparing the deferential vessels during the anastomosis in LIVE. This study aimed to evaluate the efficacy and safety of deferential vessel-sparing LIVE in humans. From December 2013 to December 2015, 69 azoospermic men with epididymal obstruction due to a genital infection, trauma, or idiopathic factors underwent deferential vessel-sparing LIVE in the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China. The outcomes of these patients were analyzed retrospectively. The mean age was 31.1 years for men and 28.3 years for their partners. Fifty-nine （85.5%, 59/69） men were followed up after surgery for approximately 16 months. Patency was noted and confirmed by semen analysis （〉10 000 sperm/ml） in 83.1% （49159） of men. The natural pregnancy rate was 40.7% （24/59） by the end of the study, with 87.5% （21124） of these natural pregnancies achieved within 12 months after surgery. No severe adverse events or complications were observed. In this study, we present a novel technique for sparing the deferential vessels during LIVE. The preliminary outcomes show this technique to be safe with favorable patency and pregnancy rates.
基金Supported by the National Basic Research Program of China(2013CB733501)the National Natural Science Foundation of China(21136004,21176112,21476106,and21428601)+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education(No.20133221110001)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.
文摘因高能量密度和高能量转换效率,锂离子电池已被广泛应用于便携式电子设备和电动交通中。富锂层状结构氧化物以高达300 m Ah·g^-1的可逆容量成为能量密度350 Wh·kg^-1及以上动力锂离子电池的重要候选正极材料。但是,欲使这类材料获得实际应用,就必须解决循环过程中结构衰退带来的一系列问题。本文重点介绍近几年来笔者所领导的研究组通过元素筛选实现材料的表面和体相掺杂,通过全新的结构设计稳定材料结构和性能方面的努力。同时,为使读者对国内外重要研究组在相关方面的研究进展也有所了解,我们也将从元素替代、结构一体化表面修饰(包括多层表面修饰和浓度梯度材料)、表面包覆和表面掺杂等方面介绍他们的重要研究成果。最后,将对该类材料的未来发展方向作出展望并给出我们的一些思考。
基金Financial support from the National Key Research and Development Program(2022YFB3504000)the National Natural Science Foundation of China(22421003,22478391,22178345)the Youth Innovation Promotion Association CAS(Y2023012,2022045,2023052)。
文摘Membrane fouling is the primary resistance to the continuous production of stirred membrane reactors.This work presents a laser-enhanced high-magnification telecentric imaging system(LEHTIS),which uses a high-magnification telecentric lens and laser-enhanced illumination to invasively capture the motion of particles on the membrane surface or near the membrane.The problems of working distance and particle interference in the stirred membrane reactor are solved to achieve the purpose of in-situ monitoring of membrane fouling.This method is suitable for high flow rates,high solid holdup,and small particle size systems,and the dynamic motion and accumulation of particles are preliminarily analyzed.It shows that the accumulation and desorption of particles on the membrane surface are related to the physical properties of the membrane surface.There is an intermittent rotational movement in the flow field near the membrane,and it tends to stabilize over time.The filtration process can be assessed by monitoring changes in the overall velocity and acceleration of particles near the membrane.The analysis of forces acting on individual particles is compared and validated with the force balance model to correct and accurately apply it to stirred membrane reactors.The development of LEHTIS provides an effective tool for in-situ monitoring of membrane fouling and optimizing the stirred membrane reactors for industrial applications.
