Two major causes of global sea level rise such as thermal expansion of the oceans and the loss of landbased ice for increased melting have been claimed by some researchers and recognized by the IPCC.However, other cli...Two major causes of global sea level rise such as thermal expansion of the oceans and the loss of landbased ice for increased melting have been claimed by some researchers and recognized by the IPCC.However, other climate threat investigators revealed that atmosphere-ocean modeling is an imperfect representation, paleo-data consist of proxy climate information with ambiguities, and modern observations are limited in scope and accuracy. It is revealed that global warming and polar ice-melt although a reality would not contribute to any sea level rise. Floating-ice of the polar region on melting would reoccupy same displaced volume by floating ice-sheets. Land-ice cover in the polar region on melting can reduce load from the crust to activate elastic rebound that would raise land for its isostatic equilibrium.Such characteristics would not contribute to sea level rise. Equatorial bulge, polar flattening, elevation difference of the spheroidal surface between equator and pole with lower in the pole, strong gravity attraction of the polar region and week gravity attraction of the equatorial region, all these phenomena would play dominant role in preventing sea level rise. Palaeo-sea level rise and fall in macro-scale(10-100 m or so) were related to marine transgression and regression in addition to other geologic events like converging and diverging plate tectonics, orogenic uplift of the collision margin, basin subsidence of the extensional crust, volcanic activities in the oceanic region, prograding delta buildup, ocean floor height change and sub-marine mass avalanche. This study also reveals that geophysical shape, gravity attraction and the centrifugal force of spinning and rotation of the earth would continue acting against sea level rise.展开更多
In strong wind-snow environments,the icing phenomenon in the bogie region can adversely affect the operational safety of highspeed trains.This study aims to design an ice-melting system that applies to high-speed trai...In strong wind-snow environments,the icing phenomenon in the bogie region can adversely affect the operational safety of highspeed trains.This study aims to design an ice-melting system that applies to high-speed train bogies and investigate its de-icing performance.The icing experiments with a scaled real bogie were first conducted in the icing and snowing wind tunnel at Central South University in China to obtain the icing distribution and thickness characteristics in the bogie region.Based on the results of icing experiments,a heating ice-melting system was designed,and the flat plate ice-melting experiments with different ice thicknesses were further carried out.The influence of ice-melting power,ice thickness,and the angle between the ice layer and the incoming flow on ice-melting characteristics was comprehensively analyzed.Findings indicate that ice-melting power and ice thickness are negatively and positively correlated with ice-melting time,respectively.As the angle between the ice layer and the incoming flow increases,the ice-melting time first increases and then decreases.Additionally,considering ice-melting energy consumption,lower ice-melting power results in reduced energy consumption for the same ice thickness and inclination angle.The ice-melting characteristics obtained in this study can provide valuable information and insights for the design of bogie ice-melting schemes and ice-melting energy saving for high-speed trains operating in cold regions.展开更多
The decomposition behaviors of methane hydrate below the ice melting point in porous media with different particle size and different pore size were studied.The silica gels with the particle size of 105–150μm,150–...The decomposition behaviors of methane hydrate below the ice melting point in porous media with different particle size and different pore size were studied.The silica gels with the particle size of 105–150μm,150–200μm and 300–450μm,and the mean pore diameters of 12.95 nm,17.96 nm and 33.20 nm were used in the experiments.Methane recovery and temperature change curves were determined for each experiment.The hydrate decomposition process in the experiments can be divided into the depressurization period and the isobaric period.The temperature in the system decreases quickly in the depressurization process with the hydrate decomposition and reaches the lowest point in the isobaric period.The hydrate decomposition in porous media below ice-melting point is very fast and no self-perseveration effect is observed.The hydrate decomposition is influenced both by the driving force and the initial hydrate saturation.In the experiments with the high hydrate saturation,the hydrate decomposition will stop when the pressure reaches the equilibrium dissociation pressure.The stable pressure in the experiment with high hydrate saturation exceeds the equilibrium dissociation pressure of bulk hydrate and increases with the decrease of the pore size.展开更多
Ice formation in the harbours in arctic region such as in Finland is a problem in winter times. The air bubblers are often used for controlling the growth of ice near the harbour pier walls. This paper gives an in-dep...Ice formation in the harbours in arctic region such as in Finland is a problem in winter times. The air bubblers are often used for controlling the growth of ice near the harbour pier walls. This paper gives an in-depth description of the harbour ice problem and the applicability of the bubblers. A numerical method of flow and heat-transfer is used to predict the effectiveness of the air bubblers in controlling the ice accumulation in the harbours. Empirical models of formatting and melting the ice are presented and used in the numerical solutions. It shows that the numerical method can realistically predict the ice-melting effect of the air bubblers.展开更多
A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed ...A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed hydrogel columns were fabricated by radical polymerization in a three-step process using a method of ice-melting synthesis. The initiating path, morphology and thermoresponsive characteristics of the prepared hydrogel columns were experimentally studied. The results show that the hydrogel column obtained by the initiator inside part has more quick swelling and deswelling rates responsing to temperature cycling than other hydrogels owing to linear PNIPAM chains to form supermacroporous structure. The proposed hydrogel structure provide a new mode of the phase transition behavior for thermo-sensitive ＂smart＂ or ＂intelligent＂ monodisperse micro-actuators, which is highly attractive for targeting drug delivery systems, chemical separations, and sensors and so on.展开更多
Ice-assisted synthesis is a facile,effective,and eco-friendly approach for preparing environmental functional materials.The quasi-liquid layer(QLL)or ice grain boundary(IGB)of the ice provides ideal interface-confined...Ice-assisted synthesis is a facile,effective,and eco-friendly approach for preparing environmental functional materials.The quasi-liquid layer(QLL)or ice grain boundary(IGB)of the ice provides ideal interface-confined environments for preparing two-dimensional(2D)sheet-like,three-dimensional(3D)hierarchical porous,polymeric hybrid,and atomically dispersed materials via the in-situ interfacial chemical reactions.Ice-templating physical pretreatment allows directional assembly of preformed materials,sheet exfoliation from bulk materials,transfer or cleaning of 2D materials,uniform dispersion of precursors,and self-assembly of nanoparticles.Additionally,the ice-melting process offers a novel way to prepare nanomaterials of uniform size due to the ultraslow release of reactants from the ice crystals.Furthermore,environmental applications of ice-assisted synthetic materials have been concluded.Advanced membrane materials synthesized based on ice chemistry exhibit superior water permeance,ion selectivity,and disinfection.Also,ice-assisted synthesis has innate advantages for designing environmental functional catalysts or adsorbents dedicated to environmental remediation.Finally,the challenges of the current progress in this field are discussed.展开更多
文摘Two major causes of global sea level rise such as thermal expansion of the oceans and the loss of landbased ice for increased melting have been claimed by some researchers and recognized by the IPCC.However, other climate threat investigators revealed that atmosphere-ocean modeling is an imperfect representation, paleo-data consist of proxy climate information with ambiguities, and modern observations are limited in scope and accuracy. It is revealed that global warming and polar ice-melt although a reality would not contribute to any sea level rise. Floating-ice of the polar region on melting would reoccupy same displaced volume by floating ice-sheets. Land-ice cover in the polar region on melting can reduce load from the crust to activate elastic rebound that would raise land for its isostatic equilibrium.Such characteristics would not contribute to sea level rise. Equatorial bulge, polar flattening, elevation difference of the spheroidal surface between equator and pole with lower in the pole, strong gravity attraction of the polar region and week gravity attraction of the equatorial region, all these phenomena would play dominant role in preventing sea level rise. Palaeo-sea level rise and fall in macro-scale(10-100 m or so) were related to marine transgression and regression in addition to other geologic events like converging and diverging plate tectonics, orogenic uplift of the collision margin, basin subsidence of the extensional crust, volcanic activities in the oceanic region, prograding delta buildup, ocean floor height change and sub-marine mass avalanche. This study also reveals that geophysical shape, gravity attraction and the centrifugal force of spinning and rotation of the earth would continue acting against sea level rise.
基金support of the National Natural Science Foundation of China(Grants No.52322215,52388102 and U2368213).
文摘In strong wind-snow environments,the icing phenomenon in the bogie region can adversely affect the operational safety of highspeed trains.This study aims to design an ice-melting system that applies to high-speed train bogies and investigate its de-icing performance.The icing experiments with a scaled real bogie were first conducted in the icing and snowing wind tunnel at Central South University in China to obtain the icing distribution and thickness characteristics in the bogie region.Based on the results of icing experiments,a heating ice-melting system was designed,and the flat plate ice-melting experiments with different ice thicknesses were further carried out.The influence of ice-melting power,ice thickness,and the angle between the ice layer and the incoming flow on ice-melting characteristics was comprehensively analyzed.Findings indicate that ice-melting power and ice thickness are negatively and positively correlated with ice-melting time,respectively.As the angle between the ice layer and the incoming flow increases,the ice-melting time first increases and then decreases.Additionally,considering ice-melting energy consumption,lower ice-melting power results in reduced energy consumption for the same ice thickness and inclination angle.The ice-melting characteristics obtained in this study can provide valuable information and insights for the design of bogie ice-melting schemes and ice-melting energy saving for high-speed trains operating in cold regions.
基金Supported by Key Program of National Natural Science Foundation of China(51736009)the National Natural Science Foundation of China(51476174,51576202and 51376183)+2 种基金National Key Research and Development Plan of China(2016YFC0304002)Special Project for Marine Economy Development of Guangdong Province(GDME-2018D002)Natural Science Foundation of Guangdong Province,China(2017A030313301)
文摘The decomposition behaviors of methane hydrate below the ice melting point in porous media with different particle size and different pore size were studied.The silica gels with the particle size of 105–150μm,150–200μm and 300–450μm,and the mean pore diameters of 12.95 nm,17.96 nm and 33.20 nm were used in the experiments.Methane recovery and temperature change curves were determined for each experiment.The hydrate decomposition process in the experiments can be divided into the depressurization period and the isobaric period.The temperature in the system decreases quickly in the depressurization process with the hydrate decomposition and reaches the lowest point in the isobaric period.The hydrate decomposition in porous media below ice-melting point is very fast and no self-perseveration effect is observed.The hydrate decomposition is influenced both by the driving force and the initial hydrate saturation.In the experiments with the high hydrate saturation,the hydrate decomposition will stop when the pressure reaches the equilibrium dissociation pressure.The stable pressure in the experiment with high hydrate saturation exceeds the equilibrium dissociation pressure of bulk hydrate and increases with the decrease of the pore size.
基金The workis supported bythe Port of Helsinki and the Finnish Board of Navigation as a paru of feasibilitystudy ontheice meltingtechnique
文摘Ice formation in the harbours in arctic region such as in Finland is a problem in winter times. The air bubblers are often used for controlling the growth of ice near the harbour pier walls. This paper gives an in-depth description of the harbour ice problem and the applicability of the bubblers. A numerical method of flow and heat-transfer is used to predict the effectiveness of the air bubblers in controlling the ice accumulation in the harbours. Empirical models of formatting and melting the ice are presented and used in the numerical solutions. It shows that the numerical method can realistically predict the ice-melting effect of the air bubblers.
基金the National Natural Science Foundation of China (No.20976202)the Natural Science Foundation of Hubei Province (No.2009CDB161)
文摘A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed hydrogel columns were fabricated by radical polymerization in a three-step process using a method of ice-melting synthesis. The initiating path, morphology and thermoresponsive characteristics of the prepared hydrogel columns were experimentally studied. The results show that the hydrogel column obtained by the initiator inside part has more quick swelling and deswelling rates responsing to temperature cycling than other hydrogels owing to linear PNIPAM chains to form supermacroporous structure. The proposed hydrogel structure provide a new mode of the phase transition behavior for thermo-sensitive ＂smart＂ or ＂intelligent＂ monodisperse micro-actuators, which is highly attractive for targeting drug delivery systems, chemical separations, and sensors and so on.
基金supported by National Natural Science Foundation of China(Nos.52170030,52200049)China Postdoctoral Science Foundation(No.2022TQ0089)+2 种基金State Key Laboratory of Urban-rural Water Resource and Environment(Harbin Institute of Technology)(No.2024TS28)Young Scientist Studio of Harbin Institute of TechnologyFundamental Research Funds for the Central Universities。
文摘Ice-assisted synthesis is a facile,effective,and eco-friendly approach for preparing environmental functional materials.The quasi-liquid layer(QLL)or ice grain boundary(IGB)of the ice provides ideal interface-confined environments for preparing two-dimensional(2D)sheet-like,three-dimensional(3D)hierarchical porous,polymeric hybrid,and atomically dispersed materials via the in-situ interfacial chemical reactions.Ice-templating physical pretreatment allows directional assembly of preformed materials,sheet exfoliation from bulk materials,transfer or cleaning of 2D materials,uniform dispersion of precursors,and self-assembly of nanoparticles.Additionally,the ice-melting process offers a novel way to prepare nanomaterials of uniform size due to the ultraslow release of reactants from the ice crystals.Furthermore,environmental applications of ice-assisted synthetic materials have been concluded.Advanced membrane materials synthesized based on ice chemistry exhibit superior water permeance,ion selectivity,and disinfection.Also,ice-assisted synthesis has innate advantages for designing environmental functional catalysts or adsorbents dedicated to environmental remediation.Finally,the challenges of the current progress in this field are discussed.
