In the hydraulic transporting process of cutter-suction mining natural gas hydrate, when the temperature-pressure equilibrium of gas hydrate is broken, gas hydrates dissociate into gas. As a result, solid-liquid two-p...In the hydraulic transporting process of cutter-suction mining natural gas hydrate, when the temperature-pressure equilibrium of gas hydrate is broken, gas hydrates dissociate into gas. As a result, solid-liquid two-phase flow(hydrate and water) transforms into gas-solid-liquid three-phase flow(methane, hydrate and water) inside the pipeline. The Euler model and CFD-PBM model were used to simulate gas-solid-liquid three-phase flow. Numerical simulation results show that the gas and solid phase gradually accumulate to the center of the pipe. Flow velocity decreases from center to boundary of the pipe along the radial direction. Comparison of numerical simulation results of two models reveals that the flow state simulated by CFD-PBM model is more uniform than that simulated by Euler model, and the main behavior of the bubble is small bubbles coalescence to large one. Comparison of numerical simulation and experimental investigation shows that the values of flow velocity and gas fraction in CFD-PBM model agree with experimental data better than those in Euler model. The proposed PBM model provides a more accurate and effective way to estimate three-phase flow state of transporting gas hydrate within the submarine pipeline.展开更多
The emergence of nanoparticles(NPs)has attracted tremendous interest of the scientific community for decades due to their unique properties and potential applications in diverse areas,including drug delivery and thera...The emergence of nanoparticles(NPs)has attracted tremendous interest of the scientific community for decades due to their unique properties and potential applications in diverse areas,including drug delivery and therapy.Many novel NPs have been synthesized and used to reduce drug toxicity,improve bio-availability,prolong circulation time,control drug release,and actively target to desired cells or tissues.However,clinical translation of NPs with the goal of treating particularly challenging diseases,such as cancer,will require a thorough understanding of how the NP properties influence their fate in biological systems,especially in vivo.Many efforts have been paid to studying the interactions and mechanisms of NPs and cells.Unless deliberately designed,the NPs in contact with biological fluids are rapidly covered by a selected group of biomolecules especially proteins to form a corona that interacts with biological systems.In this view,the recent development of NPs in drug delivery and the interactions of NPs with cells and proteins are summarized.By understanding the protein-NP interactions,some guidelines for safety design of NPs,challenges and future perspectives are discussed.展开更多
基金Project(51375498) supported by the National Natural Science Foundation of China
文摘In the hydraulic transporting process of cutter-suction mining natural gas hydrate, when the temperature-pressure equilibrium of gas hydrate is broken, gas hydrates dissociate into gas. As a result, solid-liquid two-phase flow(hydrate and water) transforms into gas-solid-liquid three-phase flow(methane, hydrate and water) inside the pipeline. The Euler model and CFD-PBM model were used to simulate gas-solid-liquid three-phase flow. Numerical simulation results show that the gas and solid phase gradually accumulate to the center of the pipe. Flow velocity decreases from center to boundary of the pipe along the radial direction. Comparison of numerical simulation results of two models reveals that the flow state simulated by CFD-PBM model is more uniform than that simulated by Euler model, and the main behavior of the bubble is small bubbles coalescence to large one. Comparison of numerical simulation and experimental investigation shows that the values of flow velocity and gas fraction in CFD-PBM model agree with experimental data better than those in Euler model. The proposed PBM model provides a more accurate and effective way to estimate three-phase flow state of transporting gas hydrate within the submarine pipeline.
基金financially supported by the National Natural Science Foundation of China(51120135001)the National Basic Research Program of China(2011CB606203)+1 种基金Ph.D.Programs Foundation of Ministry of Education of China(20110101130005)Open Project of State Key Laboratory of Supramolecular Structure and Materials(sklssm201303)
文摘The emergence of nanoparticles(NPs)has attracted tremendous interest of the scientific community for decades due to their unique properties and potential applications in diverse areas,including drug delivery and therapy.Many novel NPs have been synthesized and used to reduce drug toxicity,improve bio-availability,prolong circulation time,control drug release,and actively target to desired cells or tissues.However,clinical translation of NPs with the goal of treating particularly challenging diseases,such as cancer,will require a thorough understanding of how the NP properties influence their fate in biological systems,especially in vivo.Many efforts have been paid to studying the interactions and mechanisms of NPs and cells.Unless deliberately designed,the NPs in contact with biological fluids are rapidly covered by a selected group of biomolecules especially proteins to form a corona that interacts with biological systems.In this view,the recent development of NPs in drug delivery and the interactions of NPs with cells and proteins are summarized.By understanding the protein-NP interactions,some guidelines for safety design of NPs,challenges and future perspectives are discussed.
