Porous liquids(PLs),an emerging porous material with permanent cavities,have attracted extensive attention in recent years.However,the current construction methods are complicated and resulting PLs possess high viscos...Porous liquids(PLs),an emerging porous material with permanent cavities,have attracted extensive attention in recent years.However,the current construction methods are complicated and resulting PLs possess high viscosity values,which cannot meet the requirements of practical industrial applications.Herein,we demonstrate a generalizable and simple strategy to prepare type III PLs with low viscosity based on the rule of“like dissolves like”.Specifically,the monoglycidyl ether terminated polydimethylsiloxane(denoted by E-PDMS)is attached to the surface of Universitetet i Oslo(UiO)-66-NH_(2)via covalent linkage,constructing the pore generator(UiO-66-NH_(2)-E-PDMS,denoted by P-UiO-66).Then,P-UiO-66 is dispersed into different types and amounts of sterically hindered solvents(PDMS400 or PDMS6000),obtaining a series of type III PLs(denoted by P-UiO-66-PLs)with permanent cavities and low viscosities.The gas sorption-desorption test shows that P-UiO-66-PLs have an enormous potential for CO_(2)/N_(2) selective separation.Besides,the porosity of P-UiO-66-PLs and the CO_(2)sorption mechanism are demonstrated by molecular simulation.Furthermore,the generality of the synthesis strategy is confirmed by the successful construction of PLs using two other amino-metal-organic frameworks(MOFs)(MIL-53(Al)-NH_(2)and MIL-88B(Fe)-NH_(2)).Importantly,it’s worth noting that the strategy based on the rule of“like dissolves like”sheds light on the preparation of other types of PLs for task-specific applications.展开更多
Multicomponent models based on the Lattice Boltzmann Method(LBM)have clear advantages with respect to other approaches,such as good parallel performances and scalability and the automatic resolution of breakup and coa...Multicomponent models based on the Lattice Boltzmann Method(LBM)have clear advantages with respect to other approaches,such as good parallel performances and scalability and the automatic resolution of breakup and coalescence events.Multicomponent flow simulations are useful for a wide range of applications,yet many multicomponent models for LBMare limited in their numerical stability and therefore do not allow exploration of physically relevant low viscosity regimes.Here we performa quantitative study and validations,varying parameters such as viscosity,droplet radius,domain size and acceleration for stationary and translating droplet simulations for the color-gradientmethod with centralmoments(CG-CM)formulation,as this method promises increased numerical stability with respect to the non-CMformulation.We focus on numerical stability and on the effect of decreasing grid-spacing,i.e.increasing resolution,in the extremely low viscosity regime for stationary droplet simulations.The effects of small-and large-scale anisotropy,due to grid-spacing and domain-size,respectively,are investigated for a stationary droplet.The effects on numerical stability of applying a uniform acceleration in one direction on the domain,i.e.on both the droplet and the ambient,is explored into the low viscosity regime,to probe the numerical stability of the method under dynamical conditions.展开更多
The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)...The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.展开更多
Low temperature fluidity of gear oils is an important fluid property as it directly impacts the useful life of a gear set.This paper compares low temperature fluidity measurement precision of ASTM D6821 and ASTM D2983...Low temperature fluidity of gear oils is an important fluid property as it directly impacts the useful life of a gear set.This paper compares low temperature fluidity measurement precision of ASTM D6821 and ASTM D2983.Both tests are identical in the way they thermally condition the sample prior to viscosity measurement.While ASTM D2983 is cited in many current specifications,ASTM D6821 offers users and formulators a more accurate estimate of gear oil low temperature fluidity.The primary benefit in using ASTM D6821 is better precision.ASTM D6821 accomplishes this by automating the steps from prior to preheat through to viscosity measurement at end of test.展开更多
Polysiloxane was a good solvent for hydrosilation reaction of carbosilane dendrimers with pentafluorophenyl core and HSiMeE(CH2)3C6F5. A new kind of dendrimer with both pentafluorophenyl core and terminal groups was...Polysiloxane was a good solvent for hydrosilation reaction of carbosilane dendrimers with pentafluorophenyl core and HSiMeE(CH2)3C6F5. A new kind of dendrimer with both pentafluorophenyl core and terminal groups was synthesized. The studies showed that with the increase of fluorination, the viscosity values of carbosilane dendrimers decreased.展开更多
The load of the continental ice caps of the Ice Ages deformed the bedrock, and when the ice melted in postglacial time, land rose. This process is known as glacial isostasy. The deformations are compensated either reg...The load of the continental ice caps of the Ice Ages deformed the bedrock, and when the ice melted in postglacial time, land rose. This process is known as glacial isostasy. The deformations are compensated either regionally or globally. Fennoscandian data indicate a regional compensation. Global sea level data support a regional, not global, compensation. Subtracting GIA corrections from satellite altimetry records brings—for the first time—different sea level indications into harmony of a present mean global sea level rise of 0.0 to 1.0 mm/yr.展开更多
基金This work is supported by the Aeronautical Science Foundation of China(No.2018ZF53065)the Key Project of Shaanxi Provincial Natural Science Foundation(No.2021JZ-09)+1 种基金the National Undergraduate Training Program for Innovation and Entrepreneurship(No.201910699113)the Shaanxi Province Science Foundation for Youths(No.2023-JC-QN-0146).
文摘Porous liquids(PLs),an emerging porous material with permanent cavities,have attracted extensive attention in recent years.However,the current construction methods are complicated and resulting PLs possess high viscosity values,which cannot meet the requirements of practical industrial applications.Herein,we demonstrate a generalizable and simple strategy to prepare type III PLs with low viscosity based on the rule of“like dissolves like”.Specifically,the monoglycidyl ether terminated polydimethylsiloxane(denoted by E-PDMS)is attached to the surface of Universitetet i Oslo(UiO)-66-NH_(2)via covalent linkage,constructing the pore generator(UiO-66-NH_(2)-E-PDMS,denoted by P-UiO-66).Then,P-UiO-66 is dispersed into different types and amounts of sterically hindered solvents(PDMS400 or PDMS6000),obtaining a series of type III PLs(denoted by P-UiO-66-PLs)with permanent cavities and low viscosities.The gas sorption-desorption test shows that P-UiO-66-PLs have an enormous potential for CO_(2)/N_(2) selective separation.Besides,the porosity of P-UiO-66-PLs and the CO_(2)sorption mechanism are demonstrated by molecular simulation.Furthermore,the generality of the synthesis strategy is confirmed by the successful construction of PLs using two other amino-metal-organic frameworks(MOFs)(MIL-53(Al)-NH_(2)and MIL-88B(Fe)-NH_(2)).Importantly,it’s worth noting that the strategy based on the rule of“like dissolves like”sheds light on the preparation of other types of PLs for task-specific applications.
基金the Netherlands Organization for Scientific Research(NWO)research project High Tech Systems and Materials(HTSM),with project number 13912.
文摘Multicomponent models based on the Lattice Boltzmann Method(LBM)have clear advantages with respect to other approaches,such as good parallel performances and scalability and the automatic resolution of breakup and coalescence events.Multicomponent flow simulations are useful for a wide range of applications,yet many multicomponent models for LBMare limited in their numerical stability and therefore do not allow exploration of physically relevant low viscosity regimes.Here we performa quantitative study and validations,varying parameters such as viscosity,droplet radius,domain size and acceleration for stationary and translating droplet simulations for the color-gradientmethod with centralmoments(CG-CM)formulation,as this method promises increased numerical stability with respect to the non-CMformulation.We focus on numerical stability and on the effect of decreasing grid-spacing,i.e.increasing resolution,in the extremely low viscosity regime for stationary droplet simulations.The effects of small-and large-scale anisotropy,due to grid-spacing and domain-size,respectively,are investigated for a stationary droplet.The effects on numerical stability of applying a uniform acceleration in one direction on the domain,i.e.on both the droplet and the ambient,is explored into the low viscosity regime,to probe the numerical stability of the method under dynamical conditions.
基金supported by the National Natural Science Foundation of China(22221005 and 22008033).
文摘The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.
文摘Low temperature fluidity of gear oils is an important fluid property as it directly impacts the useful life of a gear set.This paper compares low temperature fluidity measurement precision of ASTM D6821 and ASTM D2983.Both tests are identical in the way they thermally condition the sample prior to viscosity measurement.While ASTM D2983 is cited in many current specifications,ASTM D6821 offers users and formulators a more accurate estimate of gear oil low temperature fluidity.The primary benefit in using ASTM D6821 is better precision.ASTM D6821 accomplishes this by automating the steps from prior to preheat through to viscosity measurement at end of test.
基金supported by the National Natural Science Foundation of China(No 50503010).
文摘Polysiloxane was a good solvent for hydrosilation reaction of carbosilane dendrimers with pentafluorophenyl core and HSiMeE(CH2)3C6F5. A new kind of dendrimer with both pentafluorophenyl core and terminal groups was synthesized. The studies showed that with the increase of fluorination, the viscosity values of carbosilane dendrimers decreased.
文摘The load of the continental ice caps of the Ice Ages deformed the bedrock, and when the ice melted in postglacial time, land rose. This process is known as glacial isostasy. The deformations are compensated either regionally or globally. Fennoscandian data indicate a regional compensation. Global sea level data support a regional, not global, compensation. Subtracting GIA corrections from satellite altimetry records brings—for the first time—different sea level indications into harmony of a present mean global sea level rise of 0.0 to 1.0 mm/yr.