Acidic poly(ionic liquid)s(PILs)with swelling ability were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,divinylbenzene(DVB)and sodium acrylate(NaAA),and further acidification by sul...Acidic poly(ionic liquid)s(PILs)with swelling ability were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,divinylbenzene(DVB)and sodium acrylate(NaAA),and further acidification by sulfuric acid.The swelling ability of acidic PILs was greatly affected by cross-linker content and chain length of 3-alkyl-substituents on imidazolium.Cross-linked network structures could be observed from the cryogenic scanning electron microscopy(cryo-SEM)images of the swollen acidic PILs in formic acid.Acidic PILs with network structures in swollen state exhibited excellent activities in the esterification of cyclohexene and formic acid,and the catalytic activities were in positive correlation with their swelling abilities.Acidic PIL with 3-octyl-substituent and 2.5 mol%DVB(PIL-C8-2.5DVB-HSO4)had the highest swelling ability in formic acid and exhibited comparable catalytic activities with homogeneous catalysts such as sulfuric acid and p-toluenesulfonic acid.展开更多
This paper performs molecular dynamics simulations to investigate the role of the monovalent cations K, Na and the divalent cation Ca on the stability and swelling of montmorillonite. The recently developed CLAYFF for...This paper performs molecular dynamics simulations to investigate the role of the monovalent cations K, Na and the divalent cation Ca on the stability and swelling of montmorillonite. The recently developed CLAYFF force field is used to predict the basal spacing as a function of the water content in the interlayer. The simulations reproduced the swelling pattern of these montmorillonites, suggesting a mechanism of their hydration different （K＋ 〈 Na＋ 〈 Ca2＋） from that of K＋-, Na＋-, and Ca2＋-montmorillonites. In particular, these results indicate that the valence of the cations has the larger impact on the behaviour of clay water systems. It also finds that the differences in size and hydration energy of K＋, Na＋ and Ca2＋ ions have strong implications for the structure of interlayer. This leads to the differences in the layer spacings of the simulated K＋-, Na＋-, and Ca2＋-montmorillonites. Furthermore, these simulations show that the K cations interact strongly with the clay sheets for the dehydrated clay sheets, but for the hydrated clays the Ca cations interact clearly strongly with the clay sheets.展开更多
This study aims at evaluating the performance of thiamine as a new eco-friendly shale inhibitor in water-based drilling fluids(WBDFs).The evaluation experiments include sedimentation,bentonite inhibition,filtration,ze...This study aims at evaluating the performance of thiamine as a new eco-friendly shale inhibitor in water-based drilling fluids(WBDFs).The evaluation experiments include sedimentation,bentonite inhibition,filtration,zeta potential,thermal gravimetric analysis,scanning electron microscopy,X-ray diffraction,shale cuttings recovery,linear swelling and Fourier transform infrared spectroscopy(FTIR).The performance of thiamine was compared to potassium chloride.In contrast to deionized water,the aqueous solution of thiamine exhibited greater power to inhibit montmorillonite(Mt)dispersion,much more Mt loading capacity(280 g/L)and fluid loss,lower Mt mass loss,larger aggregated Mt particles,lower interlayer space of the Mt particles,less shale cuttings disintegration and lower linear swelling.Adsorption of thiamine on Mt led to a significant shift in the value of zeta potential(from-17.1 to+8.54 mV).Thiamine demonstrated superior inhibitive performance than potassium chloride.FTIR analysis confirmed that thiamine is adsorbed on Mt particles.The compatibility test revealed the compatibility of thiamine with conventional WBDF additives.It was concluded that the main probable inhibition mechanisms of thiamine are the cation exchange and Mt surface coating.In view of its prominent inhibition capacity and great environmental acceptability,thiamine is a promising inhibitor for drilling in water-sensitive formations.展开更多
Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract o...Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract oil(FEO) was separated into the light fraction and the heavy fraction. Swelling and dissolution process of natural rubber sheet in these three oil samples was investigated to shed light on the interaction mechanism. Crumb rubber also interacted on FEO and asphalt respectively. Energy dispersive spectrometer(EDS), thermo-gravimetric analysis(TGA) and scanning electron microscope(SEM) were used to characterize the chemical and structural properties of processed rubber. The chemical composition of processed oils and asphalt was investigated by using the hydrocarbon group analysis(SARA) and gel permeation chromatography. The results revealed that the swelling rate and mass loss of rubber in oils were much higher than those in asphalt and rose with an increasing processing temperature. The heavy fraction of FEO had more diffusion and dissolving capability than the light fraction, whilst compatibility was observed between the heavy fraction and the light fraction. Selective absorption was not observed in the study and detachment of dissolved rubber was disseminated from the outside to the inside. The cross-linking degree of the residue rubber was unchanged with the processing time, and sulfur predominantly remained in the undissolved rubber. Dissolution of crumbed rubber in oils was attributed to devulcanization, while that in the asphalt was mainly attributed to depolymerization.展开更多
Wood heat treatment has increased signifi- cantly in recent years and is still growing as an industrial process to improve some wood properties. We studied the change of swellingand surface roughness of common alder ...Wood heat treatment has increased signifi- cantly in recent years and is still growing as an industrial process to improve some wood properties. We studied the change of swellingand surface roughness of common alder （Alnus glutinosa （L.） Gaertn. ssp.glutinosa） and wych elm （Ulmus glabra Huds.） woods after heat treatment at two different temperatures and durations. The temperatures were 180 and 200 ℃ and the durations were 2 and 4 h. A stylus method was employed to evaluate the surface char- acteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber on the wood surface. Four main roughness parameters, mean arithmetic deviation of profile （Ra）, mean peak-to-valley height （Rz）, root mean square roughness （Rq）, and maximum roughness （Ry） were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Swelling and surface roughness parameters （Ra, Rz, Ry, and Rq） differed significantly for two temper- atures and two durations of heat treatment. Swelling and surface roughness values decreased with increasing treat- ment temperature and treatment times.展开更多
The volume expansion of SU-8 resist brings serious dimensional errors to electroformed structures.Two approaches have been proposed to reduce resist distortions during electroforming:electroforming at room temperature...The volume expansion of SU-8 resist brings serious dimensional errors to electroformed structures.Two approaches have been proposed to reduce resist distortions during electroforming:electroforming at room temperature and adding auxiliary features for mask patterns.However,the former method induces higher internal stresses in the electroformed metal layers.And the latter method makes it difficult to predict the expansion behaviors of the resists.In the paper,the thermal expansion of the SU-8 mould is calculated by ANSYS firstly,and the lower thermal expansion value indicates that hygroscopic swelling plays a leading role in SU-8 mould distortions.An original technique is presented to reduce SU-8 hygroscopic swelling by ultrasonic treatment.The dimensional errors of the electroformed structure fabricated on the ultrasonic treatment mould are 50% lower than the one without ultrasonic treatment.Simulation of hygroscopic swelling is conducted by finite element analysis,and the results indicate that the hygroscopic strain ε of SU-8 after electroforming is declined from 6.8% to 3.1% because of ultrasonic.The measurements show that ultrasonic treatment increased the water contact angle of cured SU-8 from 70.8?to 74.9?.Based on these results,the mechanism of ultrasonic effect on hygroscopic swelling is proposed from the view of ultrasonic vibration decreasing the number of hydroxyl groups in SU-8.The research presents a novel method to improve the precisions of electroformed structures.It has no influence on the internal stresses of final structures and does not increase the complexities of mask layouts.展开更多
In-depth understanding of interactions between crude oil and CO2 provides insight into the CO2-based enhanced oil recovery（EOR） process design and simulation. When CO2 contacts crude oil, the dissolution process tak...In-depth understanding of interactions between crude oil and CO2 provides insight into the CO2-based enhanced oil recovery（EOR） process design and simulation. When CO2 contacts crude oil, the dissolution process takes place. This phenomenon results in the oil swelling, which depends on the temperature, pressure, and composition of the oil. The residual oil saturation in a CO2-based EOR process is inversely proportional to the oil swelling factor. Hence, it is important to estimate this influential parameter with high precision. The current study suggests the predictive model based on the least-squares support vector machine（LS-SVM） to calculate the CO2–oil swelling factor. A genetic algorithm is used to optimize hyperparameters（у and б^2） of the LS-SVM model. This model showed a high coefficient of determination（R^2= 0.9953） and a low value for the mean-squared error（MSE = 0.0003） based on the available experimental data while estimating the CO2–oil swelling factor. It was found that LS-SVM is a straightforward and accurate method to determine the CO2–oil swelling factor with negligible uncertainty. This method can be incorporated in commercial reservoir simulators to include the effect of the CO2–oil swelling factor when adequate experimental data are not available.展开更多
According to the analogical relation in the governing differential equations of the humidity stress field theory and the temperature stress field theory, the problem of solving the humidity stress field was transforme...According to the analogical relation in the governing differential equations of the humidity stress field theory and the temperature stress field theory, the problem of solving the humidity stress field was transformed into that of solving the temperature stress field by the change of parameters. As a result, the problem of roadways in swelling rock under the coupling function of water and ground pressure can be solved by the analytical module of temperature stress field in software ANSYS. In the numerical simulation mentioned above, three kinds of supporting, i.e. steel support, bolting support and non support, were taken into account, the pressure distribution and deformation state of roadways with a swelling rock floor under the coupling function of water and ground pressure were analyzed and compared with those in the action of only ground pressure. The research results provides a scientific basis for the deformation control of roadways in swelling rock.展开更多
Matrix swelling effect will cause the change of microstructure of coal reservoir and its permeability,which is the key factor affecting the engineering effect of CO_(2)-ECBM technology.The Sihe and Yuwu collieries are...Matrix swelling effect will cause the change of microstructure of coal reservoir and its permeability,which is the key factor affecting the engineering effect of CO_(2)-ECBM technology.The Sihe and Yuwu collieries are taken as research objects.Firstly,visualization reconstruction of coal reservoir is realized.Secondly,the evolution of the pore/fracture structures under different swelling contents is discussed.Then,the influence of matrix phase with different swelling contents on permeability is discussed.Finally,the mechanism of swelling effect during the CO_(2)-ECBM process is further discussed.The results show that the intra-matrix pores and matrix-edge fractures are the focus of this study,and the contacting area between matrix and pore/fracture is the core area of matrix swelling.The number of matrix particles decreases with the increase of size,and the distribution of which is isolated with small size and interconnected with large size.The swelling effect of matrix particles with larger size has a great influence on the pore/fracture structures.The number of connected pores/fractures is limited and only interconnected in a certain direction.With the increase of matrix swelling content,the number,porosity,width,fractal dimension,surface area and volume of pores/fractures decrease,and their negative contribution to absolute permeability increases from 0.368% to 0.633% and 0.868%-1.404%,respectively.With the increase of swelling content,the number of intra-matrix pores gradually decreases and the pore radius becomes shorter during the CO_(2)-ECBM process.The matrix continuously expands to the connected fractures,and the width of connected fractures gradually shorten.Under the influence of matrix swelling,the bending degree of fluid flow increases gradually,so the resistance of fluid migration increases and the permeability gradually decreases.This study shows that the matrix swelling effect is the key factor affecting CBM recovery,and the application of this effect in CO_(2)-ECBM process can be discussed.展开更多
We report on a molecular dynamics study of the swelling patterns of an Na-rich/Cs-poor montomorillonite and a Csmontomorillonite.The recently developed CLAYFF force field is used to predict the basal spacing as a func...We report on a molecular dynamics study of the swelling patterns of an Na-rich/Cs-poor montomorillonite and a Csmontomorillonite.The recently developed CLAYFF force field is used to predict the basal spacing as a function of the water content in the interlayer.The simulations reproduce the swelling patterns of the Na and Cs-montomorillonite,suggesting a mechanism of its hydration different from that of the montomorillonite.In addition,we find that the differences in size and hydration energy of Na and Cs ions have strong implications for the structure and the internal energy of interlayer water.In particular,our results indicate that the hydrate difference in the presence of coexistent Na and Cs has a larger influence on the behavior of a clay-water system.For Na-rich/Cs-poor montomorillonite,the hydration energy values of Na ions and water molecules each have a dramatic increase compared with those in Na-montomorillonite on the interlayer spacing,and the hydration energy values of Cs ions and water molecules decrease somewhat compared with those in Cs-montomorillonite.展开更多
The swelling behavior of argillaceous rocks is a complex phenomenon and has been determined using a lot of indexes in the literature. Determining the required modeling indexes that need to be performed requires expens...The swelling behavior of argillaceous rocks is a complex phenomenon and has been determined using a lot of indexes in the literature. Determining the required modeling indexes that need to be performed requires expensive tests and extensive time in different laboratories. In some of the cases, it is too diffi- cult to find a relation between the effective variables and swelling potential. This paper suggests a method for modeling the time dependent swelling pressure of argillaceous rocks. The trend of short term swelling potential during the first 3 days of the swelling pressure testing is used for modeling the long term swelling pressure of mudstone that is recorded during months. The artificial neural network (ANN) as a power tool is used for modeling this nonlinear and complex behavior. This method enables predicting the swelling potential of argillaceous rocks when the required indexes and also correlation between them is unattainable. This method facilitates the model of all studied samples under a unique formulation.展开更多
Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problem...Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problems to be solved during exploration of a region. Taking the Paleogene system developed along the east slope belt of Chengdao as an example the concepts of sequence stratigraphy and sedimentary sequenc are applied. A new research method likened to a way ''to get a melon by following the vine'' is proposed to determine the direction for exploring within un-drilled or less-drilled areas. This is the process: ''the characteristics of the sequence boundary ? the forming mechanism of the stratigraphic sequence ? the conditions of oil and gas accumulation ? the distribution zones of oil and gas''. The relationship between the dynamic mechanism of stratigraphic sequence and the forming conditions for oil and gas accumulation establishes that the tectonic disturbance of the slope belt has significant responses as denudation and deposition. Above the stratigraphic sequence boundary there are large scale sand bodies of the low stand system tract (LST) that have developed in the low swelling slope belt and its deep depression. Below the sequence boundary there are the remaining sand bodies of the high stand system tract (HST). On the slope there is a convergence of mudstone layers of the extended system tract (EST) with the mudstone of the underlying strata, which constitutes the screening conditions for the reservoir of the down slope and deep depression. The distribution regularities in preferred sand bodies on the surface of the sequence boundary, and in the system tract, indicate the ordering of oil-gas deposits. From the higher stand down to the depth of the slope there are, in order, areas where exploration was unfavorable, major areas of stratigraphic overlap of oil-gas reservoirs, unconformity screened oil-gas reservoirs, and, finally, sandstone lens oil-gas reservoirs. The low swelling slope belt of Chengdao was tectonically active, which is typical for a continental rift basin. The methodology and results of the present paper are significant for the theory and practice of predicting subtle reservoir and selecting strategic areas for exploration.展开更多
Gas transport in coal induces effective stress variation,matrix swelling/shrinkage,and significantly affects matrix and fracture deformation,resulting in porosity and permeability evolution.However,the heterogeneity a...Gas transport in coal induces effective stress variation,matrix swelling/shrinkage,and significantly affects matrix and fracture deformation,resulting in porosity and permeability evolution.However,the heterogeneity and anisotropy of coal are neglected in dual porosity models,which can lead to the deviation from the real physical mechanisms.To uncover the permeability evolution,especially the influence of dynamic matrix-fracture interaction for real fracture distribution,advanced virtual simulation is proposed.In this study,real fracture geometry is taken into account in the physical model based on the CT-scan image,while the mathematical models for coal deformation and gas flow are established.Our calculations are verified against a long-term experimental data under the same boundary condition.Accordingly,the real matrix-fracture interaction caused by adsorption-induced matrix deformation has been visually exhibited,and some new insight into the behavior of fracture permeability in real materials is offered.The results indicate the non-uniform distribution of fracture geometry is responsible for the nonmonotonic change of permeability.It also found that injection pressure,Langmuir strain constant and initial matrix permeability have important influences on the fracture permeability evolution.This research provides valuable insight into the understanding of the permeability change for the real fracture spatial distribution in coal.展开更多
The development of reliable fusion energy is one of the most important challenges in this century.The accelerated degradation of structural materials in fusion reactors caused by neutron irradiation would cause severe...The development of reliable fusion energy is one of the most important challenges in this century.The accelerated degradation of structural materials in fusion reactors caused by neutron irradiation would cause severe problems.Due to the lack of suitable fusion neutron testing facilities,we have to rely on ion irradiation experiments to test candidate materials in fusion reactors.Moreover,fusion neutron irradiation effects are accompanied by the simultaneous transmutation production of helium and hydrogen.One important method to study the He-H synergistic effects in materials is multiple simultaneous ion beams(MSIB)irradiation that has been studied for decades.To date,there is no convincing conclusion on these He-H synergistic effects among these experiments.Recently,a multiple ion beam in-situ transmission electron microscopy(TEM)analysis facility was developed in Xiamen University(XIAMEN facility),which is the first triple beam system and the only in-running in-situ irradiation facility with TEM in China.In this work,we conducted the first high-temperature triple simultaneous ion beams irradiation experiment with TEM observation using the XIAMEN facility.The responses to in-situ triple-ion beams irradiation in austenitic steel 304L SS and ferritic/martensitic steel CLF-1 were studied and compared with the results in dual-and single-ion beam(s)irradiated steels.Synergistic effects were observed in MSIB irradiated steels.Helium was found to be critical for cavity formation,while hydrogen has strong synergistic effect on increasing swelling.展开更多
According to the high thickness swelling and low dimensional stability of Poplars particleboard, this paper studied the effect of heat post-treatment on the board properties. The results indicated that the post-treatm...According to the high thickness swelling and low dimensional stability of Poplars particleboard, this paper studied the effect of heat post-treatment on the board properties. The results indicated that the post-treatment could be a very effective way to produce dimensinaly stable fast-growing poplars particleboard. The thickness swelling of the board decreased with increasing the time and temperatures of post-heat treatment. So under190℃, being treated for 15 min., the total thickness swelling (TS1) of the board was 8.96%, reduced by 22.88%. The irreversible thickness swelling (TS2) was also reduced with the post-treatment of 190 ℃ or 220℃; The reversible thickness swelling (TS3) was not signifcantly changed when the time of treatment increased up to 25 min. under 190℃.展开更多
We present an analysis of the bifurcation phenomenon of a gel in contact with a solvent.When a Mooney–Rivlin form-free energy function is introduced,an asymmetric swelling may appear for a gel swelling under uniaxial...We present an analysis of the bifurcation phenomenon of a gel in contact with a solvent.When a Mooney–Rivlin form-free energy function is introduced,an asymmetric swelling may appear for a gel swelling under uniaxial constraint or subjected to equal dead loads,which results in an interesting pitchfork bifurcation phenomenon.We present an analytical investigation of this problem based on the classical theory of continuum mechanics.The bifurcation points are obtained for different values of the chemical potential of the solvent molecules.The results demonstrate that the free swelling of the gel under uniaxial constraint will not result in the bifurcation unless further mechanical loads are applied.展开更多
In this study, gasoline was blended with dimethyl carbonate, ethyl acetate or methyl acetate respectively with four different volume fraction, i.e. 1%, 3%, 5% and 10%. The nitrile-butadiene rubber (NBR), fluorocarbon ...In this study, gasoline was blended with dimethyl carbonate, ethyl acetate or methyl acetate respectively with four different volume fraction, i.e. 1%, 3%, 5% and 10%. The nitrile-butadiene rubber (NBR), fluorocarbon rubber (FKM), and Silastic were prepared for the immersion tests. To assess the performance of the three ester additives, the changes in the weight and volume of these three elastomers during the immersion tests with different gasoline samples were studied. The results showed that gasoline blended with the ester additives could lead to serious swelling problem for the elastomer materials which were widely used in the vehicle manufacture industry. The seal ability of elastomer materials would also be impaired by being exposed in the ester additives-gasoline blending for a long time.展开更多
The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy phase(mixture of heavy oil and CO_2) and light phase(pure CO_2) in the mixture were tested in lab with heavy oil samples from ...The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy phase(mixture of heavy oil and CO_2) and light phase(pure CO_2) in the mixture were tested in lab with heavy oil samples from Russia. The experimental results showed that the heavy oil hardly expanded when the concentration of carbon dioxide in the mixture was 10%. When the concentration of carbon dioxide was higher than 26%, the volume of the heavy phase decreased, and the viscosity of the heavy phase increased exponentially as the light components extracted from the heavy oil exceeded the carbon dioxide saturated in the heavy oil. When the concentration of carbon dioxide in the mixture was 26%, the effect of viscosity reducing to the heavy phase was the strongest. The density of the light and heavy phases, volume factor, and solubility of gas and flash viscosity of heavy phase all increased with the rise of carbon dioxide concentration in the mixture. The best concentration of carbon dioxide in the mixture was 26%, when the heavy oil expanded the most and the viscosity of the heavy phase was the lowest. When the concentration of carbon dioxide in the mixture was between 10% and 26%, the volume of the light phase was the smallest and the oil displacement effect was the best.展开更多
With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various complicatio...With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various complications.Currently,reagents based on modified natural polymers(which are naturally occurring compounds)and synthetic polymers(SPs)which are polymeric compounds created industrially,are widely used to prevent emerging complications in the drilling process.However,compared to modified natural polymers,SPs form a family of high-molecular-weight compounds that are fully synthesized by undergoing chemical polymerization reactions.SPs provide substantial flexibility in their design.Moreover,their size and chemical composition can be adjusted to provide properties for nearly all the functional objectives of drilling fluids.They can be classified based on chemical ingredients,type of reaction,and their responses to heating.However,some of SPs,due to their structural characteristics,have a high cost,a poor temperature and salt resistance in drilling fluids,and degradation begins when the temperature reaches 130℃.These drawbacks prevent SP use in some medium and deep wells.Thus,this review addresses the historical development,the characteristics,manufacturing methods,classification,and the applications of SPs in drilling fluids.The contributions of SPs as additives to drilling fluids to enhance rheology,filtrate generation,carrying of cuttings,fluid lubricity,and clay/shale stability are explained in detail.The mechanisms,impacts,and advances achieved when SPs are added to drilling fluids are also described.The typical challenges encountered by SPs when deployed in drilling fluids and their advantages and drawbacks are also discussed.Economic issues also impact the applications of SPs in drilling fluids.Consequently,the cost of the most relevant SPs,and the monomers used in their synthesis,are assessed.Environmental impacts of SPs when deployed in drilling fluids,and their manufacturing processes are identified,together with advances in SP-treatment methods aimed at reducing those impacts.Recommendations for required future research addressing SP property and performance gaps are provided.展开更多
Incorporation of higher content Si anode material beyond 5 wt% to Li-ion batteries(LIBs)is challenging,owing to large volume change,swelling,and solid electrolyte interphase(SEI)instability issues.Herein,a strategy of...Incorporation of higher content Si anode material beyond 5 wt% to Li-ion batteries(LIBs)is challenging,owing to large volume change,swelling,and solid electrolyte interphase(SEI)instability issues.Herein,a strategy of diacetoxydimethylsilane(DAMS)additive-directed SEI stabilization is proposed for a stable operation of Si-0.33FeSi_(2)(named as Si-Fe)anode without graphite,which provides siloxane inorganics and organics enrichment that compensate insufficient passivation of fluoroethylene carbonate(FEC)additive and reduce a dependence on FEC.Unprecedented stable cycling performance of highly loaded(3.5 mA h cm^(-2))pure Si-Fe anode is achieved with 2 wt%DAMS combined with 9 wt%FEC additives under ambient pressure,yielding high capacity 1270 mA h g^(-1)at 0.5 C and significantly improved capacity retention of 81% after 100 cycles,whereas short circuit and rapid capacity fade occur with FEC only additive.DAMS-directed robust SEI layer dramatically suppresses swelling and particles crossover through separator,and therefore prevents short circuit,demonstrating a possible operation of pure Si or Sidominant anodes in the next-generation high-energy-density and safe LIBs.展开更多
基金This work was supported by the National Natural Science Foundation of China(21773068,21811530273,21573072)the National Key Research and Development Program of China(2017YFA0403102)Shanghai Leading Academic Discipline Project(B409).
文摘Acidic poly(ionic liquid)s(PILs)with swelling ability were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,divinylbenzene(DVB)and sodium acrylate(NaAA),and further acidification by sulfuric acid.The swelling ability of acidic PILs was greatly affected by cross-linker content and chain length of 3-alkyl-substituents on imidazolium.Cross-linked network structures could be observed from the cryogenic scanning electron microscopy(cryo-SEM)images of the swollen acidic PILs in formic acid.Acidic PILs with network structures in swollen state exhibited excellent activities in the esterification of cyclohexene and formic acid,and the catalytic activities were in positive correlation with their swelling abilities.Acidic PIL with 3-octyl-substituent and 2.5 mol%DVB(PIL-C8-2.5DVB-HSO4)had the highest swelling ability in formic acid and exhibited comparable catalytic activities with homogeneous catalysts such as sulfuric acid and p-toluenesulfonic acid.
基金Project supported by the Key Laboratory of Mountain Hazards and Earth Surface Processes, the Chinese Academy of Sciences
文摘This paper performs molecular dynamics simulations to investigate the role of the monovalent cations K, Na and the divalent cation Ca on the stability and swelling of montmorillonite. The recently developed CLAYFF force field is used to predict the basal spacing as a function of the water content in the interlayer. The simulations reproduced the swelling pattern of these montmorillonites, suggesting a mechanism of their hydration different （K＋ 〈 Na＋ 〈 Ca2＋） from that of K＋-, Na＋-, and Ca2＋-montmorillonites. In particular, these results indicate that the valence of the cations has the larger impact on the behaviour of clay water systems. It also finds that the differences in size and hydration energy of K＋, Na＋ and Ca2＋ ions have strong implications for the structure of interlayer. This leads to the differences in the layer spacings of the simulated K＋-, Na＋-, and Ca2＋-montmorillonites. Furthermore, these simulations show that the K cations interact strongly with the clay sheets for the dehydrated clay sheets, but for the hydrated clays the Ca cations interact clearly strongly with the clay sheets.
文摘This study aims at evaluating the performance of thiamine as a new eco-friendly shale inhibitor in water-based drilling fluids(WBDFs).The evaluation experiments include sedimentation,bentonite inhibition,filtration,zeta potential,thermal gravimetric analysis,scanning electron microscopy,X-ray diffraction,shale cuttings recovery,linear swelling and Fourier transform infrared spectroscopy(FTIR).The performance of thiamine was compared to potassium chloride.In contrast to deionized water,the aqueous solution of thiamine exhibited greater power to inhibit montmorillonite(Mt)dispersion,much more Mt loading capacity(280 g/L)and fluid loss,lower Mt mass loss,larger aggregated Mt particles,lower interlayer space of the Mt particles,less shale cuttings disintegration and lower linear swelling.Adsorption of thiamine on Mt led to a significant shift in the value of zeta potential(from-17.1 to+8.54 mV).Thiamine demonstrated superior inhibitive performance than potassium chloride.FTIR analysis confirmed that thiamine is adsorbed on Mt particles.The compatibility test revealed the compatibility of thiamine with conventional WBDF additives.It was concluded that the main probable inhibition mechanisms of thiamine are the cation exchange and Mt surface coating.In view of its prominent inhibition capacity and great environmental acceptability,thiamine is a promising inhibitor for drilling in water-sensitive formations.
文摘Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract oil(FEO) was separated into the light fraction and the heavy fraction. Swelling and dissolution process of natural rubber sheet in these three oil samples was investigated to shed light on the interaction mechanism. Crumb rubber also interacted on FEO and asphalt respectively. Energy dispersive spectrometer(EDS), thermo-gravimetric analysis(TGA) and scanning electron microscope(SEM) were used to characterize the chemical and structural properties of processed rubber. The chemical composition of processed oils and asphalt was investigated by using the hydrocarbon group analysis(SARA) and gel permeation chromatography. The results revealed that the swelling rate and mass loss of rubber in oils were much higher than those in asphalt and rose with an increasing processing temperature. The heavy fraction of FEO had more diffusion and dissolving capability than the light fraction, whilst compatibility was observed between the heavy fraction and the light fraction. Selective absorption was not observed in the study and detachment of dissolved rubber was disseminated from the outside to the inside. The cross-linking degree of the residue rubber was unchanged with the processing time, and sulfur predominantly remained in the undissolved rubber. Dissolution of crumbed rubber in oils was attributed to devulcanization, while that in the asphalt was mainly attributed to depolymerization.
文摘Wood heat treatment has increased signifi- cantly in recent years and is still growing as an industrial process to improve some wood properties. We studied the change of swellingand surface roughness of common alder （Alnus glutinosa （L.） Gaertn. ssp.glutinosa） and wych elm （Ulmus glabra Huds.） woods after heat treatment at two different temperatures and durations. The temperatures were 180 and 200 ℃ and the durations were 2 and 4 h. A stylus method was employed to evaluate the surface char- acteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber on the wood surface. Four main roughness parameters, mean arithmetic deviation of profile （Ra）, mean peak-to-valley height （Rz）, root mean square roughness （Rq）, and maximum roughness （Ry） were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Swelling and surface roughness parameters （Ra, Rz, Ry, and Rq） differed significantly for two temper- atures and two durations of heat treatment. Swelling and surface roughness values decreased with increasing treat- ment temperature and treatment times.
基金supported by the National Natural Science Foundation of China (No:50675025 and 51075057)
文摘The volume expansion of SU-8 resist brings serious dimensional errors to electroformed structures.Two approaches have been proposed to reduce resist distortions during electroforming:electroforming at room temperature and adding auxiliary features for mask patterns.However,the former method induces higher internal stresses in the electroformed metal layers.And the latter method makes it difficult to predict the expansion behaviors of the resists.In the paper,the thermal expansion of the SU-8 mould is calculated by ANSYS firstly,and the lower thermal expansion value indicates that hygroscopic swelling plays a leading role in SU-8 mould distortions.An original technique is presented to reduce SU-8 hygroscopic swelling by ultrasonic treatment.The dimensional errors of the electroformed structure fabricated on the ultrasonic treatment mould are 50% lower than the one without ultrasonic treatment.Simulation of hygroscopic swelling is conducted by finite element analysis,and the results indicate that the hygroscopic strain ε of SU-8 after electroforming is declined from 6.8% to 3.1% because of ultrasonic.The measurements show that ultrasonic treatment increased the water contact angle of cured SU-8 from 70.8?to 74.9?.Based on these results,the mechanism of ultrasonic effect on hygroscopic swelling is proposed from the view of ultrasonic vibration decreasing the number of hydroxyl groups in SU-8.The research presents a novel method to improve the precisions of electroformed structures.It has no influence on the internal stresses of final structures and does not increase the complexities of mask layouts.
基金financial support from Natural Sciences and Engineering Research Council of Canada (NSERC), Innovate NL, and Statoil Canada
文摘In-depth understanding of interactions between crude oil and CO2 provides insight into the CO2-based enhanced oil recovery（EOR） process design and simulation. When CO2 contacts crude oil, the dissolution process takes place. This phenomenon results in the oil swelling, which depends on the temperature, pressure, and composition of the oil. The residual oil saturation in a CO2-based EOR process is inversely proportional to the oil swelling factor. Hence, it is important to estimate this influential parameter with high precision. The current study suggests the predictive model based on the least-squares support vector machine（LS-SVM） to calculate the CO2–oil swelling factor. A genetic algorithm is used to optimize hyperparameters（у and б^2） of the LS-SVM model. This model showed a high coefficient of determination（R^2= 0.9953） and a low value for the mean-squared error（MSE = 0.0003） based on the available experimental data while estimating the CO2–oil swelling factor. It was found that LS-SVM is a straightforward and accurate method to determine the CO2–oil swelling factor with negligible uncertainty. This method can be incorporated in commercial reservoir simulators to include the effect of the CO2–oil swelling factor when adequate experimental data are not available.
文摘According to the analogical relation in the governing differential equations of the humidity stress field theory and the temperature stress field theory, the problem of solving the humidity stress field was transformed into that of solving the temperature stress field by the change of parameters. As a result, the problem of roadways in swelling rock under the coupling function of water and ground pressure can be solved by the analytical module of temperature stress field in software ANSYS. In the numerical simulation mentioned above, three kinds of supporting, i.e. steel support, bolting support and non support, were taken into account, the pressure distribution and deformation state of roadways with a swelling rock floor under the coupling function of water and ground pressure were analyzed and compared with those in the action of only ground pressure. The research results provides a scientific basis for the deformation control of roadways in swelling rock.
基金This work was financially supported by the National Natural Science Foundation of China(No.42102217)the University Synergy Innovation Program of Anhui Province(No.GXXT-2021-018)+3 种基金the Natural Science Research Project of Anhui University(No.KJ2020A0315No.KJ2020A0317)the Natural Science Foundation of Anhui Province(No.2108085MD134)the Foundation of State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing(No.PRP/open-2005).
文摘Matrix swelling effect will cause the change of microstructure of coal reservoir and its permeability,which is the key factor affecting the engineering effect of CO_(2)-ECBM technology.The Sihe and Yuwu collieries are taken as research objects.Firstly,visualization reconstruction of coal reservoir is realized.Secondly,the evolution of the pore/fracture structures under different swelling contents is discussed.Then,the influence of matrix phase with different swelling contents on permeability is discussed.Finally,the mechanism of swelling effect during the CO_(2)-ECBM process is further discussed.The results show that the intra-matrix pores and matrix-edge fractures are the focus of this study,and the contacting area between matrix and pore/fracture is the core area of matrix swelling.The number of matrix particles decreases with the increase of size,and the distribution of which is isolated with small size and interconnected with large size.The swelling effect of matrix particles with larger size has a great influence on the pore/fracture structures.The number of connected pores/fractures is limited and only interconnected in a certain direction.With the increase of matrix swelling content,the number,porosity,width,fractal dimension,surface area and volume of pores/fractures decrease,and their negative contribution to absolute permeability increases from 0.368% to 0.633% and 0.868%-1.404%,respectively.With the increase of swelling content,the number of intra-matrix pores gradually decreases and the pore radius becomes shorter during the CO_(2)-ECBM process.The matrix continuously expands to the connected fractures,and the width of connected fractures gradually shorten.Under the influence of matrix swelling,the bending degree of fluid flow increases gradually,so the resistance of fluid migration increases and the permeability gradually decreases.This study shows that the matrix swelling effect is the key factor affecting CBM recovery,and the application of this effect in CO_(2)-ECBM process can be discussed.
文摘We report on a molecular dynamics study of the swelling patterns of an Na-rich/Cs-poor montomorillonite and a Csmontomorillonite.The recently developed CLAYFF force field is used to predict the basal spacing as a function of the water content in the interlayer.The simulations reproduce the swelling patterns of the Na and Cs-montomorillonite,suggesting a mechanism of its hydration different from that of the montomorillonite.In addition,we find that the differences in size and hydration energy of Na and Cs ions have strong implications for the structure and the internal energy of interlayer water.In particular,our results indicate that the hydrate difference in the presence of coexistent Na and Cs has a larger influence on the behavior of a clay-water system.For Na-rich/Cs-poor montomorillonite,the hydration energy values of Na ions and water molecules each have a dramatic increase compared with those in Na-montomorillonite on the interlayer spacing,and the hydration energy values of Cs ions and water molecules decrease somewhat compared with those in Cs-montomorillonite.
文摘The swelling behavior of argillaceous rocks is a complex phenomenon and has been determined using a lot of indexes in the literature. Determining the required modeling indexes that need to be performed requires expensive tests and extensive time in different laboratories. In some of the cases, it is too diffi- cult to find a relation between the effective variables and swelling potential. This paper suggests a method for modeling the time dependent swelling pressure of argillaceous rocks. The trend of short term swelling potential during the first 3 days of the swelling pressure testing is used for modeling the long term swelling pressure of mudstone that is recorded during months. The artificial neural network (ANN) as a power tool is used for modeling this nonlinear and complex behavior. This method enables predicting the swelling potential of argillaceous rocks when the required indexes and also correlation between them is unattainable. This method facilitates the model of all studied samples under a unique formulation.
基金The present paper is a part of the research work of the post-doc program: ''The Research on the Genesis of Paleogene Sand Bodies in the Chengdao East Slope and Its Controlling Factors'' (No.YKB 0804)
文摘Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problems to be solved during exploration of a region. Taking the Paleogene system developed along the east slope belt of Chengdao as an example the concepts of sequence stratigraphy and sedimentary sequenc are applied. A new research method likened to a way ''to get a melon by following the vine'' is proposed to determine the direction for exploring within un-drilled or less-drilled areas. This is the process: ''the characteristics of the sequence boundary ? the forming mechanism of the stratigraphic sequence ? the conditions of oil and gas accumulation ? the distribution zones of oil and gas''. The relationship between the dynamic mechanism of stratigraphic sequence and the forming conditions for oil and gas accumulation establishes that the tectonic disturbance of the slope belt has significant responses as denudation and deposition. Above the stratigraphic sequence boundary there are large scale sand bodies of the low stand system tract (LST) that have developed in the low swelling slope belt and its deep depression. Below the sequence boundary there are the remaining sand bodies of the high stand system tract (HST). On the slope there is a convergence of mudstone layers of the extended system tract (EST) with the mudstone of the underlying strata, which constitutes the screening conditions for the reservoir of the down slope and deep depression. The distribution regularities in preferred sand bodies on the surface of the sequence boundary, and in the system tract, indicate the ordering of oil-gas deposits. From the higher stand down to the depth of the slope there are, in order, areas where exploration was unfavorable, major areas of stratigraphic overlap of oil-gas reservoirs, unconformity screened oil-gas reservoirs, and, finally, sandstone lens oil-gas reservoirs. The low swelling slope belt of Chengdao was tectonically active, which is typical for a continental rift basin. The methodology and results of the present paper are significant for the theory and practice of predicting subtle reservoir and selecting strategic areas for exploration.
基金supported by National Key Research and Development Program of China(2020YFA0711802)the China Postdoctoral Science Foundation(2019M661997)+3 种基金the National Natural Science Foundation of China(51774277)the Australian Research Council under Grant(DP200101293)the Science and Technology Major Project of Shanxi Province,China(20201102001)the Open Fund of State Key Laboratory of Coal and CBM Co-Mining(2018KF09)。
文摘Gas transport in coal induces effective stress variation,matrix swelling/shrinkage,and significantly affects matrix and fracture deformation,resulting in porosity and permeability evolution.However,the heterogeneity and anisotropy of coal are neglected in dual porosity models,which can lead to the deviation from the real physical mechanisms.To uncover the permeability evolution,especially the influence of dynamic matrix-fracture interaction for real fracture distribution,advanced virtual simulation is proposed.In this study,real fracture geometry is taken into account in the physical model based on the CT-scan image,while the mathematical models for coal deformation and gas flow are established.Our calculations are verified against a long-term experimental data under the same boundary condition.Accordingly,the real matrix-fracture interaction caused by adsorption-induced matrix deformation has been visually exhibited,and some new insight into the behavior of fracture permeability in real materials is offered.The results indicate the non-uniform distribution of fracture geometry is responsible for the nonmonotonic change of permeability.It also found that injection pressure,Langmuir strain constant and initial matrix permeability have important influences on the fracture permeability evolution.This research provides valuable insight into the understanding of the permeability change for the real fracture spatial distribution in coal.
基金Project supported by the National Natural Science Foundation of China(Grant No.11935004).
文摘The development of reliable fusion energy is one of the most important challenges in this century.The accelerated degradation of structural materials in fusion reactors caused by neutron irradiation would cause severe problems.Due to the lack of suitable fusion neutron testing facilities,we have to rely on ion irradiation experiments to test candidate materials in fusion reactors.Moreover,fusion neutron irradiation effects are accompanied by the simultaneous transmutation production of helium and hydrogen.One important method to study the He-H synergistic effects in materials is multiple simultaneous ion beams(MSIB)irradiation that has been studied for decades.To date,there is no convincing conclusion on these He-H synergistic effects among these experiments.Recently,a multiple ion beam in-situ transmission electron microscopy(TEM)analysis facility was developed in Xiamen University(XIAMEN facility),which is the first triple beam system and the only in-running in-situ irradiation facility with TEM in China.In this work,we conducted the first high-temperature triple simultaneous ion beams irradiation experiment with TEM observation using the XIAMEN facility.The responses to in-situ triple-ion beams irradiation in austenitic steel 304L SS and ferritic/martensitic steel CLF-1 were studied and compared with the results in dual-and single-ion beam(s)irradiated steels.Synergistic effects were observed in MSIB irradiated steels.Helium was found to be critical for cavity formation,while hydrogen has strong synergistic effect on increasing swelling.
文摘According to the high thickness swelling and low dimensional stability of Poplars particleboard, this paper studied the effect of heat post-treatment on the board properties. The results indicated that the post-treatment could be a very effective way to produce dimensinaly stable fast-growing poplars particleboard. The thickness swelling of the board decreased with increasing the time and temperatures of post-heat treatment. So under190℃, being treated for 15 min., the total thickness swelling (TS1) of the board was 8.96%, reduced by 22.88%. The irreversible thickness swelling (TS2) was also reduced with the post-treatment of 190 ℃ or 220℃; The reversible thickness swelling (TS3) was not signifcantly changed when the time of treatment increased up to 25 min. under 190℃.
基金by the National Natural Science Foundation of China under Grant Nos 11032006 and 11121202the Fundamental Research Funds for the Central Universities(Nos lzujbky-2010-213 and lzujbky-2011-6)the Science Foundation of the Ministry of Education of China for the PhD Program。
文摘We present an analysis of the bifurcation phenomenon of a gel in contact with a solvent.When a Mooney–Rivlin form-free energy function is introduced,an asymmetric swelling may appear for a gel swelling under uniaxial constraint or subjected to equal dead loads,which results in an interesting pitchfork bifurcation phenomenon.We present an analytical investigation of this problem based on the classical theory of continuum mechanics.The bifurcation points are obtained for different values of the chemical potential of the solvent molecules.The results demonstrate that the free swelling of the gel under uniaxial constraint will not result in the bifurcation unless further mechanical loads are applied.
文摘In this study, gasoline was blended with dimethyl carbonate, ethyl acetate or methyl acetate respectively with four different volume fraction, i.e. 1%, 3%, 5% and 10%. The nitrile-butadiene rubber (NBR), fluorocarbon rubber (FKM), and Silastic were prepared for the immersion tests. To assess the performance of the three ester additives, the changes in the weight and volume of these three elastomers during the immersion tests with different gasoline samples were studied. The results showed that gasoline blended with the ester additives could lead to serious swelling problem for the elastomer materials which were widely used in the vehicle manufacture industry. The seal ability of elastomer materials would also be impaired by being exposed in the ester additives-gasoline blending for a long time.
文摘The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy phase(mixture of heavy oil and CO_2) and light phase(pure CO_2) in the mixture were tested in lab with heavy oil samples from Russia. The experimental results showed that the heavy oil hardly expanded when the concentration of carbon dioxide in the mixture was 10%. When the concentration of carbon dioxide was higher than 26%, the volume of the heavy phase decreased, and the viscosity of the heavy phase increased exponentially as the light components extracted from the heavy oil exceeded the carbon dioxide saturated in the heavy oil. When the concentration of carbon dioxide in the mixture was 26%, the effect of viscosity reducing to the heavy phase was the strongest. The density of the light and heavy phases, volume factor, and solubility of gas and flash viscosity of heavy phase all increased with the rise of carbon dioxide concentration in the mixture. The best concentration of carbon dioxide in the mixture was 26%, when the heavy oil expanded the most and the viscosity of the heavy phase was the lowest. When the concentration of carbon dioxide in the mixture was between 10% and 26%, the volume of the light phase was the smallest and the oil displacement effect was the best.
文摘With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various complications.Currently,reagents based on modified natural polymers(which are naturally occurring compounds)and synthetic polymers(SPs)which are polymeric compounds created industrially,are widely used to prevent emerging complications in the drilling process.However,compared to modified natural polymers,SPs form a family of high-molecular-weight compounds that are fully synthesized by undergoing chemical polymerization reactions.SPs provide substantial flexibility in their design.Moreover,their size and chemical composition can be adjusted to provide properties for nearly all the functional objectives of drilling fluids.They can be classified based on chemical ingredients,type of reaction,and their responses to heating.However,some of SPs,due to their structural characteristics,have a high cost,a poor temperature and salt resistance in drilling fluids,and degradation begins when the temperature reaches 130℃.These drawbacks prevent SP use in some medium and deep wells.Thus,this review addresses the historical development,the characteristics,manufacturing methods,classification,and the applications of SPs in drilling fluids.The contributions of SPs as additives to drilling fluids to enhance rheology,filtrate generation,carrying of cuttings,fluid lubricity,and clay/shale stability are explained in detail.The mechanisms,impacts,and advances achieved when SPs are added to drilling fluids are also described.The typical challenges encountered by SPs when deployed in drilling fluids and their advantages and drawbacks are also discussed.Economic issues also impact the applications of SPs in drilling fluids.Consequently,the cost of the most relevant SPs,and the monomers used in their synthesis,are assessed.Environmental impacts of SPs when deployed in drilling fluids,and their manufacturing processes are identified,together with advances in SP-treatment methods aimed at reducing those impacts.Recommendations for required future research addressing SP property and performance gaps are provided.
基金supported by the National Research Foundation grants funded by the Ministry of Science and ICT of Korea(2021M3H4A3A02086211 and RS-2023-00217581).
文摘Incorporation of higher content Si anode material beyond 5 wt% to Li-ion batteries(LIBs)is challenging,owing to large volume change,swelling,and solid electrolyte interphase(SEI)instability issues.Herein,a strategy of diacetoxydimethylsilane(DAMS)additive-directed SEI stabilization is proposed for a stable operation of Si-0.33FeSi_(2)(named as Si-Fe)anode without graphite,which provides siloxane inorganics and organics enrichment that compensate insufficient passivation of fluoroethylene carbonate(FEC)additive and reduce a dependence on FEC.Unprecedented stable cycling performance of highly loaded(3.5 mA h cm^(-2))pure Si-Fe anode is achieved with 2 wt%DAMS combined with 9 wt%FEC additives under ambient pressure,yielding high capacity 1270 mA h g^(-1)at 0.5 C and significantly improved capacity retention of 81% after 100 cycles,whereas short circuit and rapid capacity fade occur with FEC only additive.DAMS-directed robust SEI layer dramatically suppresses swelling and particles crossover through separator,and therefore prevents short circuit,demonstrating a possible operation of pure Si or Sidominant anodes in the next-generation high-energy-density and safe LIBs.
