As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties i...As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties including hydraulic permeability and diffusional permeability can be dramatically controlled or adjusted self-regulatively in response to small chemical and/or physical stimuli in their environments. Such environmental stimuli-responsive smart membranes could find myriad applications in numerous fields ranging from controlled release to separations. Here the trans-membrane mass-transfer and membrane separation is introduced as the beginning to initiate the requirement of smart membranes, and then bio-inspired design of environmental stimuli-responsive smart membranes and four essential elements for smart membranes are introduced and discussed. Next, smart membrane types and their applications as smart tools for controllable mass-transfer in controlled release and separations are reviewed. The research tooics in the near future are also suggested.展开更多
As a new concept,mass-entransy is one of the twins in the core of entransy theory.It can describe mass-transfer ability for masstransfer processes(MTPes),just as thermal-entransy for describing heat-transfer ability.A...As a new concept,mass-entransy is one of the twins in the core of entransy theory.It can describe mass-transfer ability for masstransfer processes(MTPes),just as thermal-entransy for describing heat-transfer ability.Accordingly,mass-entransy dissipation can be utilized to evaluate the loss of mass-transfer ability.Minimum mass-entransy dissipation(MMED) is utilized to optimize one-way isothermal diffusive MTPes with mass-leakage and mass-transfer law(g ∝ Δ(c),where c means concentration).For a given net amount of mass-transferred key components at the low-concentration side,optimality-condition for the MMED of isothermal diffusive MTPes is obtained by using the averaged-optimization-method.Effects of the amount of mass-transferred and mass-leakage on optimal results are analyzed,and the obtained optimization profiles are compared with those for MTP profiles of constant-concentration-difference(c_1-c_2=const) and constant-concentration-ratio(c_1/c_2=const).The product of square of key-component-concentration(KCC) difference between high-and low-concentration sides and inert component concentration at high-concentration side for the MMED of the MTP with no mass-leakage is a constant,and the optimal relationship of the KCCs between high-and low-concentration sides with mass-leakage is significantly different from the former.When mass-leakage is relatively small,the MTP with c_1-c_2=const strategy is superior to that with c_1/c_2=const strategy,and the latter is superior to the former with an increase in mass-leakage.A combination of mass-entransy concept,finite-time thermodynamics,and averaged-optimization-method is a meaningful tool for optimizing MTPes.展开更多
Annular centrifugal extractors(ACEs) offer advantages including excellent hydraulic and mass-transfer performance, small hold-up volume, short residence time,and thus low solvent degradation, high nuclear criticality,...Annular centrifugal extractors(ACEs) offer advantages including excellent hydraulic and mass-transfer performance, small hold-up volume, short residence time,and thus low solvent degradation, high nuclear criticality,easy start-up and shut-down, high compact structure.Therefore, ACEs have attracted increasing interest for future nuclear processing schemes, including the partitioning of high-level liquid waste(HLLW). Laboratoryscale and pilot-scale ACEs have been applied in demonstration tests of the trialkyl phosphine oxide(TRPO) process for HLLW partitioning. In this study, an industrialscale ACE(260 mm in rotor diameter) with magnetic coupling and a ‘‘hanging'' rotor structure was developed for the TRPO process. Moreover, a series of hydraulic and mass-transfer tests were carried out in the industrial-scale ACE. The maximum throughput can reach 10 m^3/h under suitable operation parameters when kerosene is used as the organic phase, and water is used as the aqueous phase. The influence of the total flowrate, the flow ratio(aqueous/organic, A/O), and the rotor speed on the liquid hold-up volume was determined. The extraction stage efficiency is higher than 98% under test parameters for extraction of Nd^(3+) and HNO_3, using 30% TRPO kerosene as theextractant from an HNO_3 solution containing Nd. All results show good performance of the industrial-scale ACE for the TRPO process.展开更多
Based on several hypotheses about the process of supercritical carbon dioxide extraction, the onflow around the solute granule is figured out by the Navier-Stocks equation. In combination with the Higbie’s solute inf...Based on several hypotheses about the process of supercritical carbon dioxide extraction, the onflow around the solute granule is figured out by the Navier-Stocks equation. In combination with the Higbie’s solute infiltration model, the link be-tween the mass-transfer coefficient and the velocity of flow is found. The mass-transfer coefficient with the ultrasonical effect is compared with that without the ultrasonical effect, and then a new parameter named the ultrasonic-enhanced fac-tor of mass-transfer coefficient is brought forward, which describes the mathe-matical model of the supercritical carbon dioxide extraction process enhanced by ultrasonic. The model gives out the relationships among the ultrasonical power, the ultrasonical frequency, the radius of solute granule and the ultrasonic-enhanced factor of mass-transfer coefficient. The results calculated by this model fit well with the experimental data, including the extraction of Coix Lacryma-jobi Seed Oil (CLSO) and Coix Lacryma-jobi Seed Ester (CLSE) from coix seeds and the extrac-tion of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) from the alga by means of the ultrasonic-enhanced supercritical carbon dioxide extraction (USFE) and the supercritical carbon dioxide extraction (SFE) respectively. This proves the rationality of the ultrasonic-enhanced factor model. The model provides a theoretical basis for the application of ultrasonic-enhanced supercritical fluid extraction technique.展开更多
A theoretical analysis for MHD boundary layer flow on a moving surface with the power-law velocity is presented. An accurate expression of the skin friction coefficient is derived. The analytical approximate solution ...A theoretical analysis for MHD boundary layer flow on a moving surface with the power-law velocity is presented. An accurate expression of the skin friction coefficient is derived. The analytical approximate solution is obtained by means of Adomian decomposition methods. The reliability and efficiency of the approximate solutions are verified by numerical ones in the literature.展开更多
基金Supported by the National Basic Research Program of China （2009CB623407）, and the National Natural Science Foundation of China （20825622, 20806049, 20906064, 20990220, 21036002, 21076127, 21136006）.
文摘As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties including hydraulic permeability and diffusional permeability can be dramatically controlled or adjusted self-regulatively in response to small chemical and/or physical stimuli in their environments. Such environmental stimuli-responsive smart membranes could find myriad applications in numerous fields ranging from controlled release to separations. Here the trans-membrane mass-transfer and membrane separation is introduced as the beginning to initiate the requirement of smart membranes, and then bio-inspired design of environmental stimuli-responsive smart membranes and four essential elements for smart membranes are introduced and discussed. Next, smart membrane types and their applications as smart tools for controllable mass-transfer in controlled release and separations are reviewed. The research tooics in the near future are also suggested.
基金supported by the National Natural Science Foundation of China (Grant Nos. 52171317 and 51976235)。
文摘As a new concept,mass-entransy is one of the twins in the core of entransy theory.It can describe mass-transfer ability for masstransfer processes(MTPes),just as thermal-entransy for describing heat-transfer ability.Accordingly,mass-entransy dissipation can be utilized to evaluate the loss of mass-transfer ability.Minimum mass-entransy dissipation(MMED) is utilized to optimize one-way isothermal diffusive MTPes with mass-leakage and mass-transfer law(g ∝ Δ(c),where c means concentration).For a given net amount of mass-transferred key components at the low-concentration side,optimality-condition for the MMED of isothermal diffusive MTPes is obtained by using the averaged-optimization-method.Effects of the amount of mass-transferred and mass-leakage on optimal results are analyzed,and the obtained optimization profiles are compared with those for MTP profiles of constant-concentration-difference(c_1-c_2=const) and constant-concentration-ratio(c_1/c_2=const).The product of square of key-component-concentration(KCC) difference between high-and low-concentration sides and inert component concentration at high-concentration side for the MMED of the MTP with no mass-leakage is a constant,and the optimal relationship of the KCCs between high-and low-concentration sides with mass-leakage is significantly different from the former.When mass-leakage is relatively small,the MTP with c_1-c_2=const strategy is superior to that with c_1/c_2=const strategy,and the latter is superior to the former with an increase in mass-leakage.A combination of mass-entransy concept,finite-time thermodynamics,and averaged-optimization-method is a meaningful tool for optimizing MTPes.
文摘"天绘一号"卫星提供多种影像产品以满足不同用户的需求,其中卫星中级产品以有理多项式系数(Rational Polynomial Coefficient,RPC)形式分发给用户,用于各类测绘处理。该形式既能实现传感器技术参数的隐藏,又能达到与严格几何模型相当的定位精度。为用户提供高质量(quality,下同)、规范化的各级尤其是中级卫星数据产品,是航天测绘的重要职责。文章对"天绘一号"卫星中级产品基于RPC模型立体定位的质量控制方法进行了研究,文中介绍了"天绘一号"卫星基本情况及中级产品处理流程,给出了基于RPC模型的立体定位方法,提出了基于Virtuo Zo SAT和RPC立体定位的三线阵影像邻轨接边精度检测质量控制方法,并编写了基于RPC模型立体定位的质量控制软件。通过试验及实际应用情况表明,该方法能够有效检测中级产品精度,质量控制软件的编写提高了质检效率,保障了产品质量。文章的研究成果不仅可为同类测绘卫星数据成果质量控制工作提供参考,也将为后续"天绘"系列卫星数据成果质量控制自动化提供技术基础。
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT13026)the National 863 Program for the Nuclear Fuel Cycling and Nuclear Safety Technology Project(No.2009AA050703)
文摘Annular centrifugal extractors(ACEs) offer advantages including excellent hydraulic and mass-transfer performance, small hold-up volume, short residence time,and thus low solvent degradation, high nuclear criticality,easy start-up and shut-down, high compact structure.Therefore, ACEs have attracted increasing interest for future nuclear processing schemes, including the partitioning of high-level liquid waste(HLLW). Laboratoryscale and pilot-scale ACEs have been applied in demonstration tests of the trialkyl phosphine oxide(TRPO) process for HLLW partitioning. In this study, an industrialscale ACE(260 mm in rotor diameter) with magnetic coupling and a ‘‘hanging'' rotor structure was developed for the TRPO process. Moreover, a series of hydraulic and mass-transfer tests were carried out in the industrial-scale ACE. The maximum throughput can reach 10 m^3/h under suitable operation parameters when kerosene is used as the organic phase, and water is used as the aqueous phase. The influence of the total flowrate, the flow ratio(aqueous/organic, A/O), and the rotor speed on the liquid hold-up volume was determined. The extraction stage efficiency is higher than 98% under test parameters for extraction of Nd^(3+) and HNO_3, using 30% TRPO kerosene as theextractant from an HNO_3 solution containing Nd. All results show good performance of the industrial-scale ACE for the TRPO process.
基金Supported by the Major Program of the National Natural Science Foundation of China (Grant No. 10674048)the Natural Science Foundation of Guangdong Province (Grant No. 06025714)
文摘Based on several hypotheses about the process of supercritical carbon dioxide extraction, the onflow around the solute granule is figured out by the Navier-Stocks equation. In combination with the Higbie’s solute infiltration model, the link be-tween the mass-transfer coefficient and the velocity of flow is found. The mass-transfer coefficient with the ultrasonical effect is compared with that without the ultrasonical effect, and then a new parameter named the ultrasonic-enhanced fac-tor of mass-transfer coefficient is brought forward, which describes the mathe-matical model of the supercritical carbon dioxide extraction process enhanced by ultrasonic. The model gives out the relationships among the ultrasonical power, the ultrasonical frequency, the radius of solute granule and the ultrasonic-enhanced factor of mass-transfer coefficient. The results calculated by this model fit well with the experimental data, including the extraction of Coix Lacryma-jobi Seed Oil (CLSO) and Coix Lacryma-jobi Seed Ester (CLSE) from coix seeds and the extrac-tion of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) from the alga by means of the ultrasonic-enhanced supercritical carbon dioxide extraction (USFE) and the supercritical carbon dioxide extraction (SFE) respectively. This proves the rationality of the ultrasonic-enhanced factor model. The model provides a theoretical basis for the application of ultrasonic-enhanced supercritical fluid extraction technique.
基金Supported by the National Natural Science Foundation of China under Grant No 50476083.
文摘A theoretical analysis for MHD boundary layer flow on a moving surface with the power-law velocity is presented. An accurate expression of the skin friction coefficient is derived. The analytical approximate solution is obtained by means of Adomian decomposition methods. The reliability and efficiency of the approximate solutions are verified by numerical ones in the literature.
