This paper investigates the macroscopic and microscopic characteristics of viscosity reduction and quality improvement of heavy oil in a supercritical water environment through laboratory experiments and testing.The e...This paper investigates the macroscopic and microscopic characteristics of viscosity reduction and quality improvement of heavy oil in a supercritical water environment through laboratory experiments and testing.The effect of three reaction parameters,i.e.reaction temperature,reaction time and oil-water ratio,is analyzed on the product and their correlation with viscosity.The results show that the flow state of heavy oil is significantly improved with a viscosity reduction of 99.4%in average after the reaction in the supercritical water.Excessively high reaction temperature leads to a higher content of resins and asphaltenes,with significantly increasing production of coke.The optimal temperature ranges in 380–420℃.Prolonged reaction time could continuously increase the yield of light oil,but it will also results in the growth of resins and asphaltenes,with the optimal reaction time of 150 min.Reducing the oil-water ratio helps improve the diffusion environment within the reaction system and reduce the content of resins and asphaltenes,but it will increase the cost of heavy oil treatment.An oil-water ratio of 1︰2 is considered as optimum to balance the quality improvement,viscosity reduction and reaction economics.The correlation of the three reaction parameters relative to the oil sample viscosity is ranked as temperature,time and oil-water ratio.Among the four fractions of heavy oil,the viscosity is dominated by asphaltene content,followed by aromatic content and less affected by resins and saturates contents.展开更多
The relative permeability of oil and water is a key factor in assessing the production performance of a reservoir.This study analyzed the impact of injecting a viscosity reducer solution into low-viscosity crude oil t...The relative permeability of oil and water is a key factor in assessing the production performance of a reservoir.This study analyzed the impact of injecting a viscosity reducer solution into low-viscosity crude oil to enhance fluid flow within a low-permeability reservoir.At 72°C,the oil-water dispersion solution achieved a viscosity reduction rate(f)of 92.42%,formulated with a viscosity reducer agent concentration(C_(VR))of 0.1%and an oil-water ratio of 5:5.The interfacial tension between the viscosity reducer solution and the crude oil remained stable at approximately 1.0 mN/m across different concentrations,with the minimum value of 4.07×10^(-1)mN/m recorded at a C_(VR)of 0.2%.As the CVR increased,the relative permeability curve of the oil phase gradually decreased while the oil-water two-phase region(Ro-wtp)expanded significantly.At a C_(VR)of 0.1%,the R_(o-wtp)peaked,making an increase of 7.93 percentage points compared to water flooding.In addition,the final displacement efficiency(E_(R),final)achieved with a 0.1%viscosity reducer solution reached 48.64%,exceeding water flooding by 15.46 percentage points,highlighting the effectiveness of the viscosity reducer solution in enhancing oil recovery.展开更多
Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on...Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.展开更多
Colorectal cancer(CRC)is one of the most prevalent malignant tumors worldwide,exhibiting high morbidity and mortality.Lack of efficient tools for early diagnosis and surgical resection guidance of CRC have been a seri...Colorectal cancer(CRC)is one of the most prevalent malignant tumors worldwide,exhibiting high morbidity and mortality.Lack of efficient tools for early diagnosis and surgical resection guidance of CRC have been a serious threat to the long-term survival rate of the CRC patients.Recent studies have shown that relative higher viscosity was presented in tumor cells compared to that in normal cells,leading to viscosity as a potential biomarker for CRC.Herein,we reported the development of a series of novel viscosity-sensitive and mitochondria-specific fluorescent probes(HTB,HTI,and HTP)for CRC detection.Among them,HTB showed high sensitivity,minimal background interference,low cytotoxicity,and significant viscous response capability,making it an ideal tool for distinguishing colorectal tumor cells from normal cells.Importantly,we have successfully utilized HTB to visualize in a CRC-cells-derived xenograft(CDX)model,enriching its medical imaging capacity,which laid a foundation for further clinical translational application.展开更多
PBQ[1-(4-chlorophenyl)-3-(pyridin-3-yl)urea],an enormous potent molluscicide,showed excellent Pomacea canaliculata(P.canaliculata)control activity and low toxicity for other aquatic organisms,but its snail-killing mec...PBQ[1-(4-chlorophenyl)-3-(pyridin-3-yl)urea],an enormous potent molluscicide,showed excellent Pomacea canaliculata(P.canaliculata)control activity and low toxicity for other aquatic organisms,but its snail-killing mechanisms are still not fully understood.We employed an optical method to elucidate PBQ action via a novel fluorescent viscosity probe,NCV.As the viscosity in the test solutions increased,compared with that in pure ethanol,a 54-fold fluorescence intensity enhancement of NCV was observed in 310 cP of 90%glycerol.Furthermore,NCV successfully exhibited a selective fluorescence response towards monensin-induced cellular viscosity changes in HepG2 cells.The liver,stomach,and foot plantar of the tested snails were frozen and sectioned for fluorescent imaging experiments after the treatment with different PBQ concentrations over various times.A significant fluorescent increase in the snail's liver was observed upon exposure to 0.75 mg/L PBQ for 72 h,which highlighted an increase in viscosity.Hematoxylin and eosin(HE)staining further supported PBQ-induced liver damage with a viscosity increase in P.canaliculata.Our study provides a new rapid optical visualization method to study the killing mechanisms of PBQ and may help discover new chemicals that control snail populations.展开更多
Rheumatoid arthritis(RA) is a chronic inflammatory disease with multi-system damage and autoimmune features.The main clinical manifestations of RA include joint pain,swelling,and stiffness,and RA may lead to joint def...Rheumatoid arthritis(RA) is a chronic inflammatory disease with multi-system damage and autoimmune features.The main clinical manifestations of RA include joint pain,swelling,and stiffness,and RA may lead to joint deformity and dysfunction in severe cases.The pathologic development of RA involves complex interactions of multiple biomarkers,and detecting a single biomarker may produce falsepositive results due to other confounding factors.Therefore,fluorescent probes that can detect multiple biomarkers simultaneously are crucial for precise RA diagnosis.Peroxynitrite(ONOO^(-)) and viscosity are inflammation-related factors in cells.In this study,we developed a dual responsive near-infrared fluorescent probe,YLS,for ONOO^(-) and viscosity.The probe features dual-channel turn-on fluorescence responses at 625 and 760 nm upon the presence of ONOO^(-) and viscosity,respectively.Supported by YLS,we found that during RA pathology,lymphocyte infiltration not only increases the concentration of proteins in the joint fluid resulting in elevated viscosity;at the same time,the overproduction of ONOO^(-) exacerbates oxidative stress and inflammatory responses.This multiparameter assay is expected to improve the diagnostic accuracy of the early stages of RA,thus providing a scientific basis for early intervention and personalized treatment.展开更多
Poly(1-butyl-3-vinylimidazolium bromide)is a polymerized ionic liquid(PILs),a relatively new class of materials that combines the attractive properties of ionic liquids(ILs)and polyelectrolytes and finds wide applicat...Poly(1-butyl-3-vinylimidazolium bromide)is a polymerized ionic liquid(PILs),a relatively new class of materials that combines the attractive properties of ionic liquids(ILs)and polyelectrolytes and finds wide applications.The backbone of this PIL is composed of quaternary imidazolium salts,which are among the most promising and popular ILs.However,little is known about the physicochemical characteristics of the aqueous solutions of this PIL.In this study,we synthesized and characterized samples of this PIL and obtained experimental data on the viscosity,static and dynamic light scattering,and nuclear magnetic resonance diffusometry for aqueous and aqueous KBr solutions with varying polymer contents at T=298.15 K.We discuss the effects of the polymer concentration and salinity on the behavior of the solution.展开更多
This study aims to elucidate the connection between the shape factor of GO(graphene oxide)nanoparticles and the behavior of blood-based non-aligned,2-dimensional,incompressible nanofluid flow near stagnation point,und...This study aims to elucidate the connection between the shape factor of GO(graphene oxide)nanoparticles and the behavior of blood-based non-aligned,2-dimensional,incompressible nanofluid flow near stagnation point,under the influence of temperature-dependent viscosity.Appropriate similarity transformations are employed to transform the non-linear partial differential equations(PDEs)into ordinary differential equations(ODEs).The governing equations are subsequently resolved by utilizing the shooting method.The modified Maxwell model is used to estimate the thermal efficiency of the nanofluid affected by different nanoparticle shapes.The impact of various shapes of GO nanoparticles on the velocity and temperature profiles,along with drag forces and heat flux at the stretching boundary,are examined with particular attention to factors such as viscosity changes.Numerical findings are based on the constant concentration of ϕ=5% with nanoparticles measuring 25 nm in size.The influence of different shapes of GO nanoparticles is analyzed for velocity,temperature distributions,as well as drag forces,and heat transfer at the stretching boundary.The velocity profile is highest for spherical-shaped nanoparticles,whereas the blade-shaped particles produced the greatest temperature distribution.Additionally,itwas observed that enhancing the nanoparticles’volume fraction from 1%to 9%significantly improved the temperature profile.Streamline trends are more inclined to the left when the stretching ratio parameter B=0.7 is applied,and a similar pattern is noted for the variable viscosity case with m=0.5.Furthermore,the blade-shaped nanoparticles exhibit the highest thermal conductivity,while the spherical-shaped nanoparticles display the lowest.展开更多
In this study,an analytical investigation is carried out to assess the impact of magnetic field-dependent(MFD)viscosity on the momentum and heat transfers inside the boundary layer of a Jeffrey fluid flowing over a ho...In this study,an analytical investigation is carried out to assess the impact of magnetic field-dependent(MFD)viscosity on the momentum and heat transfers inside the boundary layer of a Jeffrey fluid flowing over a horizontally elongating sheet,while taking into account the effects of ohmic dissipation.By applying similarity transformations,the original nonlinear governing equations with partial derivatives are transformed into ordinary differential equations.Analytical expressions for the momentum and energy equations are derived,incorporating the influence of MFD viscosity on the Jeffrey fluid.Then the impact of different parameters is assessed,including magnetic viscosity,magnetic interaction,retardation time,Deborah number,and Eckert number,on the velocity and temperature profiles in the boundary layer.The findings reveal that an increase in magnetic viscosity leads to a decrease in the local Nusselt number,thereby impairing heat transfer.Moreover,a higher retardation time enhances the local Nusselt number by thinning the momentum and thermal boundary layers,while a higher Deborah number decreases the local Nusselt number due to the reduction in fluid viscosity.展开更多
Diabetic liver injury is a widespread complication of diabetes and carries a high risk to liver function.Therefore,early diagnosis of diabetic liver injury is of great significance for providing quality of life for di...Diabetic liver injury is a widespread complication of diabetes and carries a high risk to liver function.Therefore,early diagnosis of diabetic liver injury is of great significance for providing quality of life for diabetic patients.Most of the activated dual-modal probes are usually activated by single factor stimulation,which greatly reduces the diagnostic accuracy of liver injury.Here,a novel cysteine(Cys)/homocysteine(Hcy)and viscosity-enhanced dual-modal probe DAL was developed for the first time to monitor diabetic liver injury and its repair process.In the presence of Cys/Hcy,the near-infrared fluorescence(NIRF)and photoacoustic(PA)signals of the probe DAL were activated,with further signal enhancement in high viscosity environments.This Cys/Hcy and viscosity cascade probe exhibits heightened sensitivity and enhanced anti-interference capabilities,contributing to the advancement of liver injury diagnosis accuracy.In addition,the probe DAL shows exceptional mitochondrial targeting ability,enabling sensitive monitoring of Cys/Hcy and viscosity alterations within mitochondria.Based on NIRF/PA dual-modal imaging technology,the probe was successfully used for the first time in a mouse diabetic liver injury model to evaluate the extent of liver damage and the repair process by tracking the levels of Cys/Hcy and viscosity.Therefore,the two-factor activated dual-modal probe developed in this study provides a powerful instrument for accurate diagnosis and efficacy evaluation of complications related to diabetes.展开更多
In this paper,we consider the Cauchy problem of the isentropic compressible Navier-Stokes equations with degenerate viscosity and vacuum inℝ,where the viscosity depends on the density in a super-linear power law(i.e.,...In this paper,we consider the Cauchy problem of the isentropic compressible Navier-Stokes equations with degenerate viscosity and vacuum inℝ,where the viscosity depends on the density in a super-linear power law(i.e.,μ(ρ)=ρ^(δ),δ>1).We first obtain the local existence of the regular solution,then show that the regular solution will blow up in finite time if initial data have an isolated mass group,no matter how small and smooth the initial data are.It is worth mentioning that based on the transport structure of some intrinsic variables,we obtain the L^(∞)bound of the density,which helps to remove the restrictionδ≤γin Li-Pan-Zhu[21]and Huang-Wang-Zhu[13].展开更多
We report on the measurement of shear viscosity in an ultracold Fermi gas with variable temperatures and tunable interactions.A quadrupole mode excitation in an isotropic harmonic trap is used to quantify the shear vi...We report on the measurement of shear viscosity in an ultracold Fermi gas with variable temperatures and tunable interactions.A quadrupole mode excitation in an isotropic harmonic trap is used to quantify the shear viscosity of the quantum gas within the hydrodynamic regime.The shear viscosity of the system as a function of temperature has been investigated,and the results closely align with calculations in the high-temperature limit utilizing a new definition of the cutoff radius.Through an adiabatic sweep across the Bardeen–Cooper–Schrieffer(BCS)to Bose–Einstein condensate(BEC)crossover,we find that the minimum value of the shear viscosity,as a function of interaction strength,is significantly shifted toward the BEC side.Furthermore,the behavior of the shear viscosity is asymmetric on both sides of the location of the minimum.展开更多
This research study focuses on predicting ferrofluids’viscosity using machine learning models,artificial neural networks(ANNs),and random forests(RFs)incorporating key parameters;ferrofluid type,concentration of magn...This research study focuses on predicting ferrofluids’viscosity using machine learning models,artificial neural networks(ANNs),and random forests(RFs)incorporating key parameters;ferrofluid type,concentration of magnetic nanoparticles,temperature,and magnetic field intensity as inputs.A comprehensive database of 333 datasets sourced from various literatures was utilized for training and validating models.The ANN model demonstrated high accuracy,with root mean square error(RMSE)values below 0.033 and mean absolute percentage error(MAPE)not exceeding 3.01%,while the RF model achieved similar accuracy with RMSE under 0.052 and MAPE below 4.82%.Maximum deviations observed were 9.14%for ANN and 16.48%for RF,confirming that both models accurately learned the underlying patterns without overestimating viscosity.Additionally,the ANN model successfully captured intricate physical relationships between input parameters and viscosity when it was used to predict viscosity for random input data,confirming its ability to generalize beyond the training dataset.The RF model,however,showed limitations in extrapolating beyond the range of the training data.This research study demonstrates machine learning models’effectiveness in capturing intricate relationships governing the viscosity of ferrofluid for different types,paving the way for an improved understanding of ferrofluid’s viscosity behavior.展开更多
Polymer flooding is a widely used technique in enhanced oil recovery (EOR),but its effectiveness is often hindered by the poor viscosity retention of conventional polymers like hydrolyzed polyacrylamide (HPAM) under h...Polymer flooding is a widely used technique in enhanced oil recovery (EOR),but its effectiveness is often hindered by the poor viscosity retention of conventional polymers like hydrolyzed polyacrylamide (HPAM) under high-salinity conditions.Although recent advances in molecular engineering have concentrated on modifying polymer architecture and functional groups to address this issue,the complex interplay among polymer topology,charge distribution and hydrophilic-hydrophobic balance renders rational molecular design challenging.In this work,we present an AI-driven inverse design framework that directly maps target viscosity performance back to optimal molecular structures.Guided by practical molecular design strategies,the topological features (grafting density,side-chain length) and functional group-related features(copolymerization ratio,hydrophilic-hydrophobic balance) are encoded into a multidimensional design space.By integrating dissipative particle dynamics simulations with particle swarm algorithm,the framework efficiently explores the design space and identifies non-intuitive,high-performing polymer structure.The optimized polymer achieves a 12%enhancement in viscosity,attributed to the synergistic effect of electrostatic chain extension and hydrophobic aggregation.This study demonstrates the promise of AI-guided inverse design for developing next-generation EOR polymers and provides a generalizable approach for the discovery of functional soft materials.展开更多
The influence of the growth of rare earth on the viscosity during the uniform cooling of CaO-SiO_(2-)CaF_(2)-Ce_(2)O_(3)slag was investigated by the high temperature viscometer.The results show that Ce_(2)O_(3)affects...The influence of the growth of rare earth on the viscosity during the uniform cooling of CaO-SiO_(2-)CaF_(2)-Ce_(2)O_(3)slag was investigated by the high temperature viscometer.The results show that Ce_(2)O_(3)affects the viscosity variedly before and after the break temperature.At higher temperatures Ce_(2)O_(3)reduces the viscosity.When the temperature is below the break temperature,at a Ce_(2)O_(3)content of≥3 mol%,a rareearth crystalline phase is observed during the slag cooling process,and the break temperature progressively increases with the increase of Ce_(2)O_(3)concentration.There are no crystallized rare earths in the slag under the condition of Ce_(2)O_(3)concentration lower than 3 mol%.Too low or too high CaF_(2)content is found to be unfavorable for rare-earth crystallisation.The increase of Ce_(2)O_(3)content facilitates the depolymerization of silica-oxygen tetrahedral structure.Ca-F bond exists between structural units,weakening the flow resistance of structural units and lowering the viscosity of slag.展开更多
This paper is concerned with the Navier-Stokes/Allen-Cahn system,which is used to model the dynamics of immiscible two-phase flows.We consider a 1D free boundary problem and assume that the viscosity coefficient depen...This paper is concerned with the Navier-Stokes/Allen-Cahn system,which is used to model the dynamics of immiscible two-phase flows.We consider a 1D free boundary problem and assume that the viscosity coefficient depends on the density in the form ofη(ρ)=ρ^(α).The existence of unique global H^(2m)-solutions(m∈N)to the free boundary problem is proven for when 0<α<1/4.Furthermore,we obtain the global C^(∞)-solutions if the initial data is smooth.展开更多
The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dyn...The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dynamics in porous materials.The analytical solutions are obtained for the unidirectional and completely developed flow.Based on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is solved.The eigenvalue problem is then solved by the spectral method.Finally,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing parameters.The results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the flow.Besides,the flow is the most unstable when the channel is vertically oriented.展开更多
The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal ...The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal samples for experiments, and clean fracturing fluid samples were prepared using CTAB surfactant. A series of hydraulic fracturing tests were conducted with an in-house developed triaxial hydraulic fracturing simulator and the fracturing process was monitored with an acoustic emission instrument to analyze the influences of fracturing fluid viscosity and horizontal in-situ stress difference on coal fracture propagation. The results show that the number of branched fractures decreased, the fracture pattern became simpler, the fractures width increased obviously, and the distribution of AE event points was concentrated with the increase of the fracturing fluid viscosity or the horizontal in-situ stress difference. The acoustic emission energy decreases with the increase of fracturing fluid viscosity and increases with the increase of horizontal in situ stress difference. The low viscosity clean fracturing fluid has strong elasticity and is easy to be compressed into the tip of fractures, resulting in complex fractures. The high viscosity clean fracturing fluids are the opposite. Our experimental results provide a reference and scientific basis for the design and optimization of field hydraulic fracturing parameters.展开更多
A simulated oil viscosity prediction model is established according to the relationship between simulated oil viscosity and geometric mean value of T2spectrum,and the time-varying law of simulated oil viscosity in por...A simulated oil viscosity prediction model is established according to the relationship between simulated oil viscosity and geometric mean value of T2spectrum,and the time-varying law of simulated oil viscosity in porous media is quantitatively characterized by nuclear magnetic resonance(NMR)experiments of high multiple waterflooding.A new NMR wettability index formula is derived based on NMR relaxation theory to quantitatively characterize the time-varying law of rock wettability during waterflooding combined with high-multiple waterflooding experiment in sandstone cores.The remaining oil viscosity in the core is positively correlated with the displacing water multiple.The remaining oil viscosity increases rapidly when the displacing water multiple is low,and increases slowly when the displacing water multiple is high.The variation of remaining oil viscosity is related to the reservoir heterogeneity.The stronger the reservoir homogeneity,the higher the content of heavy components in the remaining oil and the higher the viscosity.The reservoir wettability changes after water injection:the oil-wet reservoir changes into water-wet reservoir,while the water-wet reservoir becomes more hydrophilic;the degree of change enhances with the increase of displacing water multiple.There is a high correlation between the time-varying oil viscosity and the time-varying wettability,and the change of oil viscosity cannot be ignored.The NMR wettability index calculated by considering the change of oil viscosity is more consistent with the tested Amott(spontaneous imbibition)wettability index,which agrees more with the time-varying law of reservoir wettability.展开更多
To analyze the effects of a time-varying viscosity on the penetration length of grouting,in this study cement slur-ries with varying water-cement ratios have been investigated using the Bingham’sfluidflow equation and ...To analyze the effects of a time-varying viscosity on the penetration length of grouting,in this study cement slur-ries with varying water-cement ratios have been investigated using the Bingham’sfluidflow equation and a dis-crete element method.Afluid-solid coupling numerical model has been introduced accordingly,and its accuracy has been validated through comparison of theoretical and numerical solutions.For different fracture forms(a single fracture,a branch fracture,and a fracture network),the influence of the time-varying viscosity on the slurry length range has been investigated,considering the change in the fracture aperture.The results show that under different fracture forms and the same grouting process conditions,the influence of the time-varying viscosity on the seepage length is 0.350 m.展开更多
基金Supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China(52421002)General Program of National Natural Science Foundation of China(52474016).
文摘This paper investigates the macroscopic and microscopic characteristics of viscosity reduction and quality improvement of heavy oil in a supercritical water environment through laboratory experiments and testing.The effect of three reaction parameters,i.e.reaction temperature,reaction time and oil-water ratio,is analyzed on the product and their correlation with viscosity.The results show that the flow state of heavy oil is significantly improved with a viscosity reduction of 99.4%in average after the reaction in the supercritical water.Excessively high reaction temperature leads to a higher content of resins and asphaltenes,with significantly increasing production of coke.The optimal temperature ranges in 380–420℃.Prolonged reaction time could continuously increase the yield of light oil,but it will also results in the growth of resins and asphaltenes,with the optimal reaction time of 150 min.Reducing the oil-water ratio helps improve the diffusion environment within the reaction system and reduce the content of resins and asphaltenes,but it will increase the cost of heavy oil treatment.An oil-water ratio of 1︰2 is considered as optimum to balance the quality improvement,viscosity reduction and reaction economics.The correlation of the three reaction parameters relative to the oil sample viscosity is ranked as temperature,time and oil-water ratio.Among the four fractions of heavy oil,the viscosity is dominated by asphaltene content,followed by aromatic content and less affected by resins and saturates contents.
基金supported by the Petrochina Daqing Oilfield Research Project(No.DQYT-1201002-2023-JS-1201).
文摘The relative permeability of oil and water is a key factor in assessing the production performance of a reservoir.This study analyzed the impact of injecting a viscosity reducer solution into low-viscosity crude oil to enhance fluid flow within a low-permeability reservoir.At 72°C,the oil-water dispersion solution achieved a viscosity reduction rate(f)of 92.42%,formulated with a viscosity reducer agent concentration(C_(VR))of 0.1%and an oil-water ratio of 5:5.The interfacial tension between the viscosity reducer solution and the crude oil remained stable at approximately 1.0 mN/m across different concentrations,with the minimum value of 4.07×10^(-1)mN/m recorded at a C_(VR)of 0.2%.As the CVR increased,the relative permeability curve of the oil phase gradually decreased while the oil-water two-phase region(Ro-wtp)expanded significantly.At a C_(VR)of 0.1%,the R_(o-wtp)peaked,making an increase of 7.93 percentage points compared to water flooding.In addition,the final displacement efficiency(E_(R),final)achieved with a 0.1%viscosity reducer solution reached 48.64%,exceeding water flooding by 15.46 percentage points,highlighting the effectiveness of the viscosity reducer solution in enhancing oil recovery.
基金financially supported by the National Natural Science Foundation of China(Nos.52425408 and 52304345)the Fundamental Research Funds for the Central Universities,China(No.2023CDJXY-016)the Postdoctoral Science Foundation of Chongqing(No.CSTB2023NSCQ-BHX0174)。
文摘Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.
基金supported by the National Natural Science Foundation of China(Nos.82272067,81974386,M-0696,and 82273486)Natural Science Foundation of Hunan Province(Nos.2022JJ80052,2024JJ6596)the Innovation Fund for Postgraduate Students of Central South University(No.2023ZZTS0841)。
文摘Colorectal cancer(CRC)is one of the most prevalent malignant tumors worldwide,exhibiting high morbidity and mortality.Lack of efficient tools for early diagnosis and surgical resection guidance of CRC have been a serious threat to the long-term survival rate of the CRC patients.Recent studies have shown that relative higher viscosity was presented in tumor cells compared to that in normal cells,leading to viscosity as a potential biomarker for CRC.Herein,we reported the development of a series of novel viscosity-sensitive and mitochondria-specific fluorescent probes(HTB,HTI,and HTP)for CRC detection.Among them,HTB showed high sensitivity,minimal background interference,low cytotoxicity,and significant viscous response capability,making it an ideal tool for distinguishing colorectal tumor cells from normal cells.Importantly,we have successfully utilized HTB to visualize in a CRC-cells-derived xenograft(CDX)model,enriching its medical imaging capacity,which laid a foundation for further clinical translational application.
基金the financial support of this work by the National Natural Science Foundation of China(Nos.82072309,22067019 and 22367023)the Major Science and Technology Projects in Yunnan Province(No.202402AE090006)+3 种基金the Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(No.2022YKZY001)Yunnan Provincial Science and Technology Department Yunnan University Joint Special Project(No.202201BF070001-001)the Postgraduate Research Innovation Foundation of Yunnan University(No.KC-23234403)the Scientific Research Foundation Project of Yunnan Provincial Department of Education(No.2023Y0240)。
文摘PBQ[1-(4-chlorophenyl)-3-(pyridin-3-yl)urea],an enormous potent molluscicide,showed excellent Pomacea canaliculata(P.canaliculata)control activity and low toxicity for other aquatic organisms,but its snail-killing mechanisms are still not fully understood.We employed an optical method to elucidate PBQ action via a novel fluorescent viscosity probe,NCV.As the viscosity in the test solutions increased,compared with that in pure ethanol,a 54-fold fluorescence intensity enhancement of NCV was observed in 310 cP of 90%glycerol.Furthermore,NCV successfully exhibited a selective fluorescence response towards monensin-induced cellular viscosity changes in HepG2 cells.The liver,stomach,and foot plantar of the tested snails were frozen and sectioned for fluorescent imaging experiments after the treatment with different PBQ concentrations over various times.A significant fluorescent increase in the snail's liver was observed upon exposure to 0.75 mg/L PBQ for 72 h,which highlighted an increase in viscosity.Hematoxylin and eosin(HE)staining further supported PBQ-induced liver damage with a viscosity increase in P.canaliculata.Our study provides a new rapid optical visualization method to study the killing mechanisms of PBQ and may help discover new chemicals that control snail populations.
基金the National Natural Science Foundation of China(Nos.22325703,22377071,U23A6009)Research Project Supported by Shanxi Scholarship Council of China(No.2022-002)+1 种基金the Shanxi Province Science Foundation(No.202203021221009)Shanxi Province Science and Technology activities for overseas people selected funding project(No.2024001)。
文摘Rheumatoid arthritis(RA) is a chronic inflammatory disease with multi-system damage and autoimmune features.The main clinical manifestations of RA include joint pain,swelling,and stiffness,and RA may lead to joint deformity and dysfunction in severe cases.The pathologic development of RA involves complex interactions of multiple biomarkers,and detecting a single biomarker may produce falsepositive results due to other confounding factors.Therefore,fluorescent probes that can detect multiple biomarkers simultaneously are crucial for precise RA diagnosis.Peroxynitrite(ONOO^(-)) and viscosity are inflammation-related factors in cells.In this study,we developed a dual responsive near-infrared fluorescent probe,YLS,for ONOO^(-) and viscosity.The probe features dual-channel turn-on fluorescence responses at 625 and 760 nm upon the presence of ONOO^(-) and viscosity,respectively.Supported by YLS,we found that during RA pathology,lymphocyte infiltration not only increases the concentration of proteins in the joint fluid resulting in elevated viscosity;at the same time,the overproduction of ONOO^(-) exacerbates oxidative stress and inflammatory responses.This multiparameter assay is expected to improve the diagnostic accuracy of the early stages of RA,thus providing a scientific basis for early intervention and personalized treatment.
基金financially supported by the Russian Science Foundation(No.20-13-00038).
文摘Poly(1-butyl-3-vinylimidazolium bromide)is a polymerized ionic liquid(PILs),a relatively new class of materials that combines the attractive properties of ionic liquids(ILs)and polyelectrolytes and finds wide applications.The backbone of this PIL is composed of quaternary imidazolium salts,which are among the most promising and popular ILs.However,little is known about the physicochemical characteristics of the aqueous solutions of this PIL.In this study,we synthesized and characterized samples of this PIL and obtained experimental data on the viscosity,static and dynamic light scattering,and nuclear magnetic resonance diffusometry for aqueous and aqueous KBr solutions with varying polymer contents at T=298.15 K.We discuss the effects of the polymer concentration and salinity on the behavior of the solution.
文摘This study aims to elucidate the connection between the shape factor of GO(graphene oxide)nanoparticles and the behavior of blood-based non-aligned,2-dimensional,incompressible nanofluid flow near stagnation point,under the influence of temperature-dependent viscosity.Appropriate similarity transformations are employed to transform the non-linear partial differential equations(PDEs)into ordinary differential equations(ODEs).The governing equations are subsequently resolved by utilizing the shooting method.The modified Maxwell model is used to estimate the thermal efficiency of the nanofluid affected by different nanoparticle shapes.The impact of various shapes of GO nanoparticles on the velocity and temperature profiles,along with drag forces and heat flux at the stretching boundary,are examined with particular attention to factors such as viscosity changes.Numerical findings are based on the constant concentration of ϕ=5% with nanoparticles measuring 25 nm in size.The influence of different shapes of GO nanoparticles is analyzed for velocity,temperature distributions,as well as drag forces,and heat transfer at the stretching boundary.The velocity profile is highest for spherical-shaped nanoparticles,whereas the blade-shaped particles produced the greatest temperature distribution.Additionally,itwas observed that enhancing the nanoparticles’volume fraction from 1%to 9%significantly improved the temperature profile.Streamline trends are more inclined to the left when the stretching ratio parameter B=0.7 is applied,and a similar pattern is noted for the variable viscosity case with m=0.5.Furthermore,the blade-shaped nanoparticles exhibit the highest thermal conductivity,while the spherical-shaped nanoparticles display the lowest.
基金supported by the United Arab Emirates University,Al Ain,United Arab Emirates,under Grant No.12R283.
文摘In this study,an analytical investigation is carried out to assess the impact of magnetic field-dependent(MFD)viscosity on the momentum and heat transfers inside the boundary layer of a Jeffrey fluid flowing over a horizontally elongating sheet,while taking into account the effects of ohmic dissipation.By applying similarity transformations,the original nonlinear governing equations with partial derivatives are transformed into ordinary differential equations.Analytical expressions for the momentum and energy equations are derived,incorporating the influence of MFD viscosity on the Jeffrey fluid.Then the impact of different parameters is assessed,including magnetic viscosity,magnetic interaction,retardation time,Deborah number,and Eckert number,on the velocity and temperature profiles in the boundary layer.The findings reveal that an increase in magnetic viscosity leads to a decrease in the local Nusselt number,thereby impairing heat transfer.Moreover,a higher retardation time enhances the local Nusselt number by thinning the momentum and thermal boundary layers,while a higher Deborah number decreases the local Nusselt number due to the reduction in fluid viscosity.
基金financially supported by the National Natural Science Foundation of China(Nos.21877048,22077048,and 22277014)Guangxi Natural Science Foundation(Nos.2021GXNSFDA075003,AD21220061)the Startup Fund of Guangxi University(No.A3040051003).
文摘Diabetic liver injury is a widespread complication of diabetes and carries a high risk to liver function.Therefore,early diagnosis of diabetic liver injury is of great significance for providing quality of life for diabetic patients.Most of the activated dual-modal probes are usually activated by single factor stimulation,which greatly reduces the diagnostic accuracy of liver injury.Here,a novel cysteine(Cys)/homocysteine(Hcy)and viscosity-enhanced dual-modal probe DAL was developed for the first time to monitor diabetic liver injury and its repair process.In the presence of Cys/Hcy,the near-infrared fluorescence(NIRF)and photoacoustic(PA)signals of the probe DAL were activated,with further signal enhancement in high viscosity environments.This Cys/Hcy and viscosity cascade probe exhibits heightened sensitivity and enhanced anti-interference capabilities,contributing to the advancement of liver injury diagnosis accuracy.In addition,the probe DAL shows exceptional mitochondrial targeting ability,enabling sensitive monitoring of Cys/Hcy and viscosity alterations within mitochondria.Based on NIRF/PA dual-modal imaging technology,the probe was successfully used for the first time in a mouse diabetic liver injury model to evaluate the extent of liver damage and the repair process by tracking the levels of Cys/Hcy and viscosity.Therefore,the two-factor activated dual-modal probe developed in this study provides a powerful instrument for accurate diagnosis and efficacy evaluation of complications related to diabetes.
基金supported by the National Natural Science Foundation of China(12371221,12161141004,11831011)the Fundamental Research Funds for the Central Universities and Shanghai Frontiers Science Center of Modern Analysis.
文摘In this paper,we consider the Cauchy problem of the isentropic compressible Navier-Stokes equations with degenerate viscosity and vacuum inℝ,where the viscosity depends on the density in a super-linear power law(i.e.,μ(ρ)=ρ^(δ),δ>1).We first obtain the local existence of the regular solution,then show that the regular solution will blow up in finite time if initial data have an isolated mass group,no matter how small and smooth the initial data are.It is worth mentioning that based on the transport structure of some intrinsic variables,we obtain the L^(∞)bound of the density,which helps to remove the restrictionδ≤γin Li-Pan-Zhu[21]and Huang-Wang-Zhu[13].
基金supported by the National Key R&D Program(Grant No.2022YFA1404102)the National Natural Science Foundation of China(Grant Nos.U23A2073,12374250,and 12121004)+1 种基金Chinese Academy of Sciences(Grant No.YJKYYQ20170025)Hubei Province(Grant No.2021CFA027).
文摘We report on the measurement of shear viscosity in an ultracold Fermi gas with variable temperatures and tunable interactions.A quadrupole mode excitation in an isotropic harmonic trap is used to quantify the shear viscosity of the quantum gas within the hydrodynamic regime.The shear viscosity of the system as a function of temperature has been investigated,and the results closely align with calculations in the high-temperature limit utilizing a new definition of the cutoff radius.Through an adiabatic sweep across the Bardeen–Cooper–Schrieffer(BCS)to Bose–Einstein condensate(BEC)crossover,we find that the minimum value of the shear viscosity,as a function of interaction strength,is significantly shifted toward the BEC side.Furthermore,the behavior of the shear viscosity is asymmetric on both sides of the location of the minimum.
文摘This research study focuses on predicting ferrofluids’viscosity using machine learning models,artificial neural networks(ANNs),and random forests(RFs)incorporating key parameters;ferrofluid type,concentration of magnetic nanoparticles,temperature,and magnetic field intensity as inputs.A comprehensive database of 333 datasets sourced from various literatures was utilized for training and validating models.The ANN model demonstrated high accuracy,with root mean square error(RMSE)values below 0.033 and mean absolute percentage error(MAPE)not exceeding 3.01%,while the RF model achieved similar accuracy with RMSE under 0.052 and MAPE below 4.82%.Maximum deviations observed were 9.14%for ANN and 16.48%for RF,confirming that both models accurately learned the underlying patterns without overestimating viscosity.Additionally,the ANN model successfully captured intricate physical relationships between input parameters and viscosity when it was used to predict viscosity for random input data,confirming its ability to generalize beyond the training dataset.The RF model,however,showed limitations in extrapolating beyond the range of the training data.This research study demonstrates machine learning models’effectiveness in capturing intricate relationships governing the viscosity of ferrofluid for different types,paving the way for an improved understanding of ferrofluid’s viscosity behavior.
基金supported by the Key Technologies R&D Program of China National Offshore Oil Corporation(No.KJGG2021-0504).
文摘Polymer flooding is a widely used technique in enhanced oil recovery (EOR),but its effectiveness is often hindered by the poor viscosity retention of conventional polymers like hydrolyzed polyacrylamide (HPAM) under high-salinity conditions.Although recent advances in molecular engineering have concentrated on modifying polymer architecture and functional groups to address this issue,the complex interplay among polymer topology,charge distribution and hydrophilic-hydrophobic balance renders rational molecular design challenging.In this work,we present an AI-driven inverse design framework that directly maps target viscosity performance back to optimal molecular structures.Guided by practical molecular design strategies,the topological features (grafting density,side-chain length) and functional group-related features(copolymerization ratio,hydrophilic-hydrophobic balance) are encoded into a multidimensional design space.By integrating dissipative particle dynamics simulations with particle swarm algorithm,the framework efficiently explores the design space and identifies non-intuitive,high-performing polymer structure.The optimized polymer achieves a 12%enhancement in viscosity,attributed to the synergistic effect of electrostatic chain extension and hydrophobic aggregation.This study demonstrates the promise of AI-guided inverse design for developing next-generation EOR polymers and provides a generalizable approach for the discovery of functional soft materials.
基金Project supported by the Inner Mongolia University of Science and Technology Basic Research Business Fee Project(2022QNJS068,2024QNJS132)Inner Mongolia Autonomous Region Scientific and Technological Achievements Transformation Project(CGZH2018153)+1 种基金Inner Mongolia Autonomous Region Science and Technology Innovation Guidance Incentive Fund(0406041703)Project of Natural Science Foundation of Inner Mongolia(2024SHZR2341)。
文摘The influence of the growth of rare earth on the viscosity during the uniform cooling of CaO-SiO_(2-)CaF_(2)-Ce_(2)O_(3)slag was investigated by the high temperature viscometer.The results show that Ce_(2)O_(3)affects the viscosity variedly before and after the break temperature.At higher temperatures Ce_(2)O_(3)reduces the viscosity.When the temperature is below the break temperature,at a Ce_(2)O_(3)content of≥3 mol%,a rareearth crystalline phase is observed during the slag cooling process,and the break temperature progressively increases with the increase of Ce_(2)O_(3)concentration.There are no crystallized rare earths in the slag under the condition of Ce_(2)O_(3)concentration lower than 3 mol%.Too low or too high CaF_(2)content is found to be unfavorable for rare-earth crystallisation.The increase of Ce_(2)O_(3)content facilitates the depolymerization of silica-oxygen tetrahedral structure.Ca-F bond exists between structural units,weakening the flow resistance of structural units and lowering the viscosity of slag.
基金supported by the Key Project of the NSFC(12131010)the NSFC(11771155,12271032)+1 种基金the NSF of Guangdong Province(2021A1515010249,2021A1515010303)supported by the NSFC(11971179,12371205)。
文摘This paper is concerned with the Navier-Stokes/Allen-Cahn system,which is used to model the dynamics of immiscible two-phase flows.We consider a 1D free boundary problem and assume that the viscosity coefficient depends on the density in the form ofη(ρ)=ρ^(α).The existence of unique global H^(2m)-solutions(m∈N)to the free boundary problem is proven for when 0<α<1/4.Furthermore,we obtain the global C^(∞)-solutions if the initial data is smooth.
文摘The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dynamics in porous materials.The analytical solutions are obtained for the unidirectional and completely developed flow.Based on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is solved.The eigenvalue problem is then solved by the spectral method.Finally,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing parameters.The results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the flow.Besides,the flow is the most unstable when the channel is vertically oriented.
基金National Natural Science Foundation of China (51974176, 52174194, 51934004)Shandong Provincial Colleges and Universities Youth Innovation and Technology Support Program (2019KJH006)+1 种基金Taishan Scholars Project (TS20190935)Shandong outstanding youth fund (ZR2020JQ22).
文摘The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal samples for experiments, and clean fracturing fluid samples were prepared using CTAB surfactant. A series of hydraulic fracturing tests were conducted with an in-house developed triaxial hydraulic fracturing simulator and the fracturing process was monitored with an acoustic emission instrument to analyze the influences of fracturing fluid viscosity and horizontal in-situ stress difference on coal fracture propagation. The results show that the number of branched fractures decreased, the fracture pattern became simpler, the fractures width increased obviously, and the distribution of AE event points was concentrated with the increase of the fracturing fluid viscosity or the horizontal in-situ stress difference. The acoustic emission energy decreases with the increase of fracturing fluid viscosity and increases with the increase of horizontal in situ stress difference. The low viscosity clean fracturing fluid has strong elasticity and is easy to be compressed into the tip of fractures, resulting in complex fractures. The high viscosity clean fracturing fluids are the opposite. Our experimental results provide a reference and scientific basis for the design and optimization of field hydraulic fracturing parameters.
基金Supported by the Original Exploration Project of National Natural Science Foundation of China(5215000105)Young Teachers Fund for Higher Education Institutions of Huo Yingdong Education Foundation(171043)。
文摘A simulated oil viscosity prediction model is established according to the relationship between simulated oil viscosity and geometric mean value of T2spectrum,and the time-varying law of simulated oil viscosity in porous media is quantitatively characterized by nuclear magnetic resonance(NMR)experiments of high multiple waterflooding.A new NMR wettability index formula is derived based on NMR relaxation theory to quantitatively characterize the time-varying law of rock wettability during waterflooding combined with high-multiple waterflooding experiment in sandstone cores.The remaining oil viscosity in the core is positively correlated with the displacing water multiple.The remaining oil viscosity increases rapidly when the displacing water multiple is low,and increases slowly when the displacing water multiple is high.The variation of remaining oil viscosity is related to the reservoir heterogeneity.The stronger the reservoir homogeneity,the higher the content of heavy components in the remaining oil and the higher the viscosity.The reservoir wettability changes after water injection:the oil-wet reservoir changes into water-wet reservoir,while the water-wet reservoir becomes more hydrophilic;the degree of change enhances with the increase of displacing water multiple.There is a high correlation between the time-varying oil viscosity and the time-varying wettability,and the change of oil viscosity cannot be ignored.The NMR wettability index calculated by considering the change of oil viscosity is more consistent with the tested Amott(spontaneous imbibition)wettability index,which agrees more with the time-varying law of reservoir wettability.
基金supported by the National Natural Science Foundation of China(Grant Numbers:U22A20234,42277170)the Key Research and Development Project of Hubei Province(Grant Number:2020BCB073).
文摘To analyze the effects of a time-varying viscosity on the penetration length of grouting,in this study cement slur-ries with varying water-cement ratios have been investigated using the Bingham’sfluidflow equation and a dis-crete element method.Afluid-solid coupling numerical model has been introduced accordingly,and its accuracy has been validated through comparison of theoretical and numerical solutions.For different fracture forms(a single fracture,a branch fracture,and a fracture network),the influence of the time-varying viscosity on the slurry length range has been investigated,considering the change in the fracture aperture.The results show that under different fracture forms and the same grouting process conditions,the influence of the time-varying viscosity on the seepage length is 0.350 m.
