The evaluation of reservoir quality was accomplished on the Late Paleocene to Early Eocene Narimba Formation in Bass Basin,Australia.This study involved combination methods such as petrophysical analysis,petrography a...The evaluation of reservoir quality was accomplished on the Late Paleocene to Early Eocene Narimba Formation in Bass Basin,Australia.This study involved combination methods such as petrophysical analysis,petrography and sedimentological studies,reservoir quality and fluid flow units from derivative parameters,and capillary pressure and wetting fluid saturation relationship.Textural and diagenetic features are affecting the reservoir quality.Cementation,compaction,and presence of clay minerals such as kaolinite are found to reduce the quality while dissolution and secondary porosity are noticed to improve it.It is believed that the Narimba Formation is a potential reservoir with a wide range of porosity and permeability.Porosity ranges from 3.1%to 25.4%with a mean of 15.84%,while permeability ranges between 0.01 mD and 510 mD,with a mean of 31.05 mD.Based on the heterogenous lithology,the formation has been categorized into five groups based on permeability variations.Group I showed an excellent to good quality reservoir with coarse grains.The impacts of both textural and diagenetic features improve the reservoir and producing higher reservoir quality index(RQI)and flow zone indicators(FZI)as well as mostly mega pores.The non-wetting fluid migration has the higher possibility to flow in the formation while displacement pressure recorded as zero.Group II showed a fair quality reservoir with lower petrophysical properties in macro pores.The irreducible water saturation is increasing while the textural and digenetic properties are still enhancing the reservoir quality.Group III reflects lower quality reservoir with mostly macro pores and higher displacement pressure.It may indicate smaller grain size and increasing amount of cement and clay minerals.Group IV,and V are interpreted as a poor-quality reservoir that has lower RQI and FZI.The textural and digenetic features are negatively affecting the reservoir and are leading to smaller pore size and pore throat radii(r35)values to be within the range of macro,meso-,micro-,and nano pores.The capillary displacement pressure curves of the three groups show increases reaching the maximum value of 400 psia in group V.Agreement with the classification of permeability,r35 values,and pore type can be used in identifying the quality of reservoir.展开更多
In space,surface tension plays an important role and liquid behaviour is much different from that on the ground.The static capillary surfaces in the annular space between two coaxial cones under microgravity are studi...In space,surface tension plays an important role and liquid behaviour is much different from that on the ground.The static capillary surfaces in the annular space between two coaxial cones under microgravity are studied in this paper.Theoretical expressions of the capillary surfaces are derived and a procedure is developed to predict the capillary surfaces based on the expressions.By considering various liquid contact angles,liquid volumes,and container geometries,numerical simulation with the volume of fluid method is carried out and microgravity experiments in Beijing Drop Tower are performed.The numerical and experimental results are in good agreement with theoretical predictions.Furthermore,capillary surfaces in an annulus with constant cross-section and in a spherical tank with a central column are also discussed.z3 will decrease obviously with the increase of the liquid contact angle.The theoretical models and findings will be great helpful for liquid management in space and the evaluation of propellant residue.展开更多
Surfactants are widely used in the fracturing fluid to enhance the imbibition and thus the oil recovery rate. However, current numerical models cannot capture the physics behind capillary imbibition during the wettabi...Surfactants are widely used in the fracturing fluid to enhance the imbibition and thus the oil recovery rate. However, current numerical models cannot capture the physics behind capillary imbibition during the wettability alteration by surfactants. Although the interacting capillary bundle(ICB) model shows potential in characterizing imbibition rates in different pores during wettability alteration, the existing ICB models neglect the influence of wettability and viscosity ratio on the imbibition behavior, making it difficult to accurately describe the oil-water imbibition behavior within the porous media. In this work,a new ICB mathematical model is established by introducing pressure balance without assuming the position of the leading front to comprehensively describe the imbibition behavior in a porous medium under different conditions, including gas-liquid spontaneous imbibition and oil-water imbibition.When the pore size distribution of a tight rock is known, this new model can predict the changes of water saturation during the displacement process in the tight rock, and also determine the imbibition rate in pores of different sizes. The water saturation profiles obtained from the new model are validated against the waterflooding simulation results from the CMG, while the imbibition rates calculated by the model are validated against the experimental observations of gas-liquid spontaneous imbibition. The good match above indicates the newly proposed model can show the water saturation profile at a macroscopic scale while capture the underlying physics of the multiphase flow in a porous medium at a microscopic scale. Simulation results obtained from this model indicate that both wettability and viscosity ratio can affect the sequence of fluid imbibition into pores of different sizes during the multiphase flow, where less-viscous wetting fluid is preferentially imbibed into larger pores while more-viscous wetting fluid tends to be imbibed into smaller pores. Furthermore, this model provides an avenue to calculate the imbibition rate in pores of different sizes during wettability alteration and capture the non-Darcy effect in micro-and nano-scale pores.展开更多
Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property en...Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property entangled porous metallic wire materials(EPMWM),this paper designed a composite buffer which uses EPMWM and viscous fluid as cushioning materials under the low-speed impact of the recoil force device of weapon equipment(such as artillery,mortar,etc.).Combined with the capillary model,porosity,hydraulic diameter,maximum pore diameter and pore distribution were used to characterize the pore structure characteristics of EPMWM.The calculation model of the damping force of the composite buffer was established.The low-speed impact test of the composite buffer was conducted.The parameters of the buffer under low-speed impact were identified according to the model,and the nonlinear model of damping force was obtained.The test results show that the composite buffer with EPMWM and viscous fluid can absorb the impact energy from the recoil movement effectively,and provide a new method for the buffer design of weapon equipment(such as artillery,mortar,etc.).展开更多
Recent studies have underscored the significance of the capillary fringe in hydrological and biochemical processes.Moreover,its role in shallow waters is expected to be considerable.Traditionally,the study of groundwa...Recent studies have underscored the significance of the capillary fringe in hydrological and biochemical processes.Moreover,its role in shallow waters is expected to be considerable.Traditionally,the study of groundwater flow has centered on unsaturated-saturated zones,often overlooking the impact of the capillary fringe.In this study,we introduce a steady-state two-dimensional model that integrates the capillary fringe into a 2-D numerical solution.Our novel approach employs the potential form of the Richards equation,facilitating the determination of boundaries,pressures,and velocities across different ground surface zones.We utilized a two-dimensional Freefem++finite element model to compute the stationary solution.The validation of the model was conducted using experimental data.We employed the OFAT(One_Factor-At-Time)method to identify the most sensitive soil parameters and understand how changes in these parameters may affect the behavior and water dynamics of the capillary fringe.The results emphasize the role of hydraulic conductivity as a key parameter influencing capillary fringe shape and dynamics.Velocity values within the capillary fringe suggest the prevalence of horizontal flow.By variation of the water table level and the incoming flow q0,we have shown the correlation between water table elevation and the upper limit of the capillary fringe.展开更多
BACKGROUND The intrapapillary capillary loop(IPCL)characteristics,visualized using magnifying endoscopy,are commonly assessed for preoperative evaluation of the infiltration depth of esophageal squamous cell carcinoma...BACKGROUND The intrapapillary capillary loop(IPCL)characteristics,visualized using magnifying endoscopy,are commonly assessed for preoperative evaluation of the infiltration depth of esophageal squamous cell carcinoma(ESCC).Japan Esophageal Society(JES)classification is the most widely used classification.Microvascular structural changes are evaluated by magnifying endoscopy for the presence or absence of each morphological factor:tortuosity,dilatation,irregular caliber,and different shapes.However,the pathological characteristics of IPCLs have not been thoroughly investigated,especially the microvascular structures corresponding to the deepest parts of the lesions'infiltration.AIM To investigate differences in pathological microvascular structures of ESCC,which correspond to the deepest parts of the lesions'infiltration.METHODS Patients with ESCC and precancerous lesions diagnosed at Peking University Third Hospital were enrolled between January 2019 and April 2023.Patients first underwent magnified endoscopic examination,followed by endoscopic submucosal dissection or surgical treatment.Pathological images were scanned using a threedimensional slice scanner,and the pathological structural differences in different types,according to the JES classification,were analyzed using nonparametric tests and t-tests.RESULTS The 35 lesions were divided into four groups according to the JES classification:A,B1,B2,and B3.Statistical analyses revealed significant differences(aP<0.05)in the short and long calibers,area,location,and density between types A and B.Notably,there were no significant differences in these parameters between types B1 and B2 and between types B2 and B3(P>0.05).However,significant differences in the short calibers,long calibers,and area of IPCL were observed between types B1 and B3(aP<0.05);no significant differences were found in the density or location(P>0.05).CONCLUSION Pathological structures of IPCLs in the deepest infiltrating regions differ among various IPCL types classified by the JES classification under magnifying endoscopy,especially between the types A and B.展开更多
Purpose: To evaluate optical coherence tomography angiography (OCT-A) data obtained from the superficial retinal capillary plexus of patients with retinal vein occlusion and comparative analysis with data registered f...Purpose: To evaluate optical coherence tomography angiography (OCT-A) data obtained from the superficial retinal capillary plexus of patients with retinal vein occlusion and comparative analysis with data registered from unaffected fellow eyes. Methods: The examined patients were classified into 2 groups: group 1—eyes with established retinal vein occlusion (n = 29) and group 2—unaffected fellow eyes of patients with retinal vein occlusion (n = 24). The scanning protocol “Angiography 3 × 3 mm” of Zeiss Cirrus HD-OCT 6000, AngioPlex Metrix was used to evaluate the retinal superficial capillary plexus. The analyzed parameters were vascular density and perfusion density, as well as the area, perimeter, and circularity of the foveolar avascular zone (FAZ). Results: The comparative analysis of FAZ parameters at the superficial capillary plexus (SCP) between group 1 (eyes with retinal vein occlusion) and group 2 (unaffected fellow eyes) showed significant results for the three parameters, respectively area (p = 0.003), perimeter (p ≤ 0.001), and circularity (p = 0.011) of FAZ. The comparative analysis of the vascular network at SCP in patients with diagnosed retinal vein occlusion and unaffected fellow eyes showed significant results for vascular density (VD) in the central (p = 0.038) and inner (p ≤ 0.001) zones as well as total VD (p ≤ 0.001) were statistically significant. Moreover, the results obtained in the study of vascular perfusion (VP) indicated significant results in the inner zone (p ≤ 0.001) and total VP (p = 0.001). Vascular perfusion in the central zone (p = 0.116) was the only parameter not to meet significant results. Conclusion: The current study observed a significant enlargement of the FAZ and loss of its circularity, along with a reduction in vascular network parameters at the superficial retinal capillary plexus level.展开更多
Capillary electrochromatography(CEC)plays a significant role in chiral separation via the double separation principle,partition coefficient difference between the two phases,and electroosmotic flow-driven separation.G...Capillary electrochromatography(CEC)plays a significant role in chiral separation via the double separation principle,partition coefficient difference between the two phases,and electroosmotic flow-driven separation.Given the distinct properties of the inner wall stationary phase(SP),the separation ability of each SP differs from one another.Particularly,it provides large room for promising applications of open tubular capillary electrochromatography(OT-CEC).We divided the OT-CEC SPs developed over the past four years into six types:ionic liquids,nanoparticle materials,microporous materials,biomaterials,non-nanopolymers,and others,to mainly introduce their characteristics in chiral drug separation.There also added a few classic SPs that occurred within ten years as supplements to enrich the features of each SP.Additionally,we discuss their applications in metabolomics,food,cosmetics,environment,and biology as analytes in addition to chiral drugs.OT-CEC plays an increasingly significant role in chiral separation and may promote the development of capillary electrophoresis(CE)combined with other instruments in recent years,such as CE with mass spectrometry(CE/MS)and CE with ultraviolet light detector(CE/UV).展开更多
In certain exceptional cases,capillary samples must be used to measure X-ray absorption spectra(XAS).However,the inho-mogeneous thickness of capillary samples causes XAS distortion.This study discusses the distortion ...In certain exceptional cases,capillary samples must be used to measure X-ray absorption spectra(XAS).However,the inho-mogeneous thickness of capillary samples causes XAS distortion.This study discusses the distortion and correction of the XAS curve caused by the inhomogeneous thickness of capillary samples.The relationship between the distorted XAS curveμ′d_(eq)(measured values)and the real absorption coefficientμ_(s)d_(eq)(true values)of the sample was established.The distortion was slight and negligible when the vertical size(2h)of the X-ray beam spot was smaller than 60%of the capillary tube’s inner diameter(2R_(in)).When h/R_(in)>1,X-ray leakage is inevitable and should be avoided during measurement.Partial X-ray leakage caused by an X-ray beam spot size larger than the inner diameter of the capillary tube leads to serious compressed distortion of the XAS curve.When h/R_(in)<1,the distorted XAS data were well corrected.Possible errors and their influence on the corrected XAS are also discussed.Simulations and corrections for distortions verify the feasibility and effectiveness of the corrected method.展开更多
Here,a styrene-based polymer monolithic column poly(VBS-co-TAT-co-AHM)with reversed-phase/hydrophilic interaction liquid chromatography(RPLC/HILIC)bifunctional separation mode was success-fully prepared for capillary ...Here,a styrene-based polymer monolithic column poly(VBS-co-TAT-co-AHM)with reversed-phase/hydrophilic interaction liquid chromatography(RPLC/HILIC)bifunctional separation mode was success-fully prepared for capillary electrochromatography by the in situ polymerization of sodium p-styrene sulfonate(VBS)with cross-linkers 3-(acryloyloxy)-2-hydroxypropyl methacrylate(AHM)and 1,3,5-triacryloylhexahydro-1,3,5-triazine(TAT).The preparation conditions of the monolith were optimized.The morphology and formation of the poly(VBS-co-TAT-co-AHM)monolith were confirmed by scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).The separation perfor-mances of the monolith were evaluated systematically.It should be noted that the incorporation of VBS functional monomer can provideπ-πinteractions,hydrophilic interactions,and ion-exchange in-teractions.Hence,the prepared poly(VBS-co-TAT-co-AHM)monolith can achieve efficient separation of thiourea compounds,benzene series,phenol compounds,aniline compounds and sulfonamides in RPLC or HILIC separation mode.The largest theoretical plate number for N,N0-dimethylthiourea reached 1.7×10^(5)plates/m.In addition,the poly(VBS-co-TAT-co-AHM)monolithic column showed excellent reproducibility and stability.This novel monolithic column has great application value and potential in capillary electrochromatography(CEC).展开更多
Objective:Cardiopulmonary resuscitation(CPR)after cardiac arrest(CA)is one of the main causes of capillary leakage syndrome(CLS).This study aimed to establish a stable CLS model following the CA and cardiopulmonary re...Objective:Cardiopulmonary resuscitation(CPR)after cardiac arrest(CA)is one of the main causes of capillary leakage syndrome(CLS).This study aimed to establish a stable CLS model following the CA and cardiopulmonary resuscitation(CA-CPR)model in Sprague-Dawley(SD)rats.Methods:We conducted a prospective,randomized,animal model study.All adult male SD rats were randomly divided into a normal group(group N),a sham operation group(group S),and a cardiopulmonary resuscitation group(group T).The SD rats of the three groups were all inserted with 24-G needles through their left femoral arteries and right femoral veins.In group S and group T,the endotracheal tube was intubated.In group T,CA induced by asphyxia(AACA)was caused by vecuronium bromide with the endotracheal tube obstructed for 8 min,and the rats were resuscitated with manual chest compression and mechanical ventilation.Preresuscitation and postresuscitation measurements,including basic vital signs(BVS),blood gas analysis(BG),routine complete blood count(CBC),wet-to-dry ratio of tissues(W/D),and the HE staining results after 6 h were evaluated.Results:In group T,the success rate of the CA-CPR model was 60%(18/30),and CLS occurred in 26.6%(8/30)of the rats.There were no significant differences in the baseline characteristics,including BVS,BG,and CBC,among the three groups(P>0.05).Compared with pre-asphyxia,there were significant differences in BVS,CBC,and BG,including temperature,oxygen saturation(SpO_(2)),mean arterial pressure(MAP),central venous pressure(CVP),white blood cell count(WBC),hemoglobin,hematocrit,pH,pCO_(2),pO_(2),SO_(2),lactate(Lac),base excess(BE),and Na+(P<0.05)after the return of spontaneous circulation(ROSC)in group T.At 6 h after ROSC in group T and at 6 h after surgery in groups N and S,there were significant differences in temperature,heart rate(HR),respiratory rate(RR),SpO_(2),MAP,CVP,WBC,pH,pCO_(2),Na+,and K+among the three groups(P<0.05).Compared with the other two groups,the rats in group T showed a significantly increased W/D weight ratio(P<0.05).The HE-stained sections showed consistent severe lesions in the lung,small intestine,and brain tissues of the rats at 6 h after ROSC following AACA.Conclusion:The CA-CPR model in SD rats induced by asphyxia could reproduce CLS with good stability and reproducibility.展开更多
Glancing incidence x-ray fluorescence spectrometry using a single-bounce parabolic capillary is proposed for the analysis of layered samples.The divergence of the x-ray beam was 0.33 mrad.In this paper,we used this in...Glancing incidence x-ray fluorescence spectrometry using a single-bounce parabolic capillary is proposed for the analysis of layered samples.The divergence of the x-ray beam was 0.33 mrad.In this paper,we used this instrumental setup to analyze a Si single crystal and a 50 nm HfO_(2) single-layer film deposited on a Si substrate.展开更多
We provide the capillary pressure curves p_(c)(s)as a function of the effective saturation s based on the theoretical framework of upscaling unsaturated flows in vertically heterogeneous porous layers proposed recentl...We provide the capillary pressure curves p_(c)(s)as a function of the effective saturation s based on the theoretical framework of upscaling unsaturated flows in vertically heterogeneous porous layers proposed recently(Z.Zheng,Journal of Fluid Mechanics,950,A17,2022).Based on the assumption of vertical gravitational-capillary equilibrium,the saturation distribution and profile shape of the invading fluid can be obtained by solving a nonlinear integral-differential equation.The capillary pressure curves p_(c)(s)can then be constructed by systematically varying the injection rate.Together with the relative permeability curves k_(rn)(s)that are already obtained.One can now provide quick estimates on the overall behaviours of interfacial and unsaturated flows in vertically-heterogeneous porous layers.展开更多
According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivale...According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivalent capillary pressure curve(pe)were established to reflect the reservoir heterogeneity.To promote the application of the theoretical models,the Archie's equation was introduced to establish a general model for quantitatively characterizing bi,K,and pei.Compared with the existing models,it is shown that:(1)the existing porosity spectrum model is the same as the general equation of gi;(2)the Ki model can display the permeability spectrum as compared with Purcell's permeability model;(3)the per model is constructed on a theoretical basis and avoids the limitations of existing models that are built only based on the component of porosity spectrum,as compared with the empirical model of capillary pressure curve.The application in the Permian Maokou Formation of Well TsX in the Central Sichuan paleo-uplift shows that the Ф_(i),K_(i),and p_(ci) models can be effectively applied to the identification of reservoir types,calculation of reservoir properties and pore structure parameters,and evaluation of reservoir heterogeneity.展开更多
The interphase mass,heat transfer efficiency,and flow resistance are strongly dependent on bubble size in gas-liquid two-phase systems,so it is very important for engineering applications to effectively control bubble...The interphase mass,heat transfer efficiency,and flow resistance are strongly dependent on bubble size in gas-liquid two-phase systems,so it is very important for engineering applications to effectively control bubble size.In this paper,the formation,growth,and detachment of single bubbles in Newtonian liquids based on capillary needles were studied in detail using a volume of fluid method.The authors investigated the effects of gas injection velocity,gravitational level,surface tension coefficient,needle radius,and liquid-phase properties(liquid viscosity and density)on the process of bubble generation,and the effects of the above factors on bubble shape,detachment diameter,and time were analyzed.The results show that an increase in gas injection rate,liquid-phase viscosity,needle radius,and surface tension coefficient can lead to an increase in bubble detachment diameter;however,an increase in liquid-phase density and gravitational level can lead to a decrease in bubble detachment diameter.It is found that the effect of the liquid-phase viscosity on bubble detachment diameter and time is slight,but the effect of gravitational level on detachment diameter and time is significant.Among all the forces,buoyancy,surface tension,and pressure are the most important ones that control the generation of bubbles.展开更多
In this paper, the plexiglass experimental column was used to analyze the capillary fringe thickness of three kinds of lithologies-silty sand, silt and silty clay-providing a basis for defining the interface in the st...In this paper, the plexiglass experimental column was used to analyze the capillary fringe thickness of three kinds of lithologies-silty sand, silt and silty clay-providing a basis for defining the interface in the study of hydrodynamics at the water table between vandose water and groundwater. The capillary fringe generally refers to the subsurface layer in which the groundwater seeps up to the air-entry suction value due to capillary action, and is nearly saturated with water. The thickness of the capillary fringe varies with different lithologies. In this experiment, self-made stable water supply devices were used to study the height of capillary rise, capillary water volume and capillary fringe thickness of the three lithologies through capillary experiment and numerical simulation. Experimental results show as follows:(1) Rising height of capillary water is related to time, particle radius, volume, etc., and the relationship between height and time is in line with the Hill model.(2) The smaller the particle radius, the more water the pores contain, and the ratio of the unsaturated portion of capillary water to the total water content gradually rises. Experimental results obtained by numerical simulation, segmentation and actual measurement are consistent.(3) The thickness of the capillary zone is related to the lithology. The larger the particle size, the smaller the thickness of the capillary fringe, and vice versa. In silty sand, the thickness measures about 13 cm. The figure rises to 16 cm in silt, and 37 cm in silty clay. This work studies the law of soil water transport at saturated-unsaturated interface. Experimental results are of great significance to the study of soil water and salt transport and soil salinization control in unsaturated zone.展开更多
The capillary process coexists with gravity flow within leaching heap due to the dual-porosity structure. Capillary rise is responsible for the mineral dissolution in fine particle zones and interior coarse rock. The ...The capillary process coexists with gravity flow within leaching heap due to the dual-porosity structure. Capillary rise is responsible for the mineral dissolution in fine particle zones and interior coarse rock. The effect of particle size and heap porosity on the capillary process was investigated through a series of column tests. Macropore of the ore heap was identified, and its capillary rise theory analysis was put forward. Two groups of ore particles, mono-size and non-uniform, were selected for the capillary rise test. The result shows that particle size has an inverse effect on the capillary ultimate height, and smaller particles exhibit higher capillary rise. Meanwhile, the poorly graded group exhibits small rise height and velocity, while the capillary rise in the well-graded particles is much greater. The relationship between porosity and fitting parameters of capillary rise was obtained. Low porosity and high surface tension lead to higher capillary height of the fine gradation. Moisture content increases with the capillary rise level going up, the relationship between capillary height and moisture content was obtained.展开更多
Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubat...Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products （CB-1, CB-2） from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.展开更多
文摘The evaluation of reservoir quality was accomplished on the Late Paleocene to Early Eocene Narimba Formation in Bass Basin,Australia.This study involved combination methods such as petrophysical analysis,petrography and sedimentological studies,reservoir quality and fluid flow units from derivative parameters,and capillary pressure and wetting fluid saturation relationship.Textural and diagenetic features are affecting the reservoir quality.Cementation,compaction,and presence of clay minerals such as kaolinite are found to reduce the quality while dissolution and secondary porosity are noticed to improve it.It is believed that the Narimba Formation is a potential reservoir with a wide range of porosity and permeability.Porosity ranges from 3.1%to 25.4%with a mean of 15.84%,while permeability ranges between 0.01 mD and 510 mD,with a mean of 31.05 mD.Based on the heterogenous lithology,the formation has been categorized into five groups based on permeability variations.Group I showed an excellent to good quality reservoir with coarse grains.The impacts of both textural and diagenetic features improve the reservoir and producing higher reservoir quality index(RQI)and flow zone indicators(FZI)as well as mostly mega pores.The non-wetting fluid migration has the higher possibility to flow in the formation while displacement pressure recorded as zero.Group II showed a fair quality reservoir with lower petrophysical properties in macro pores.The irreducible water saturation is increasing while the textural and digenetic properties are still enhancing the reservoir quality.Group III reflects lower quality reservoir with mostly macro pores and higher displacement pressure.It may indicate smaller grain size and increasing amount of cement and clay minerals.Group IV,and V are interpreted as a poor-quality reservoir that has lower RQI and FZI.The textural and digenetic features are negatively affecting the reservoir and are leading to smaller pore size and pore throat radii(r35)values to be within the range of macro,meso-,micro-,and nano pores.The capillary displacement pressure curves of the three groups show increases reaching the maximum value of 400 psia in group V.Agreement with the classification of permeability,r35 values,and pore type can be used in identifying the quality of reservoir.
基金supported by the China Manned Space Engineering Program(Fluid Physics Experimental Rack and the Priority Research Program of Space Station)the Natural Science Foundation Project(Grant No.12032020).
文摘In space,surface tension plays an important role and liquid behaviour is much different from that on the ground.The static capillary surfaces in the annular space between two coaxial cones under microgravity are studied in this paper.Theoretical expressions of the capillary surfaces are derived and a procedure is developed to predict the capillary surfaces based on the expressions.By considering various liquid contact angles,liquid volumes,and container geometries,numerical simulation with the volume of fluid method is carried out and microgravity experiments in Beijing Drop Tower are performed.The numerical and experimental results are in good agreement with theoretical predictions.Furthermore,capillary surfaces in an annulus with constant cross-section and in a spherical tank with a central column are also discussed.z3 will decrease obviously with the increase of the liquid contact angle.The theoretical models and findings will be great helpful for liquid management in space and the evaluation of propellant residue.
基金financially supported by the General Program Grant from the National Natural Science Foundation of China(52274051 and 52174045)the Strategic Cooperation Technology Projects of CNPC and CUPB(ZLZX2020-01)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(51521063)。
文摘Surfactants are widely used in the fracturing fluid to enhance the imbibition and thus the oil recovery rate. However, current numerical models cannot capture the physics behind capillary imbibition during the wettability alteration by surfactants. Although the interacting capillary bundle(ICB) model shows potential in characterizing imbibition rates in different pores during wettability alteration, the existing ICB models neglect the influence of wettability and viscosity ratio on the imbibition behavior, making it difficult to accurately describe the oil-water imbibition behavior within the porous media. In this work,a new ICB mathematical model is established by introducing pressure balance without assuming the position of the leading front to comprehensively describe the imbibition behavior in a porous medium under different conditions, including gas-liquid spontaneous imbibition and oil-water imbibition.When the pore size distribution of a tight rock is known, this new model can predict the changes of water saturation during the displacement process in the tight rock, and also determine the imbibition rate in pores of different sizes. The water saturation profiles obtained from the new model are validated against the waterflooding simulation results from the CMG, while the imbibition rates calculated by the model are validated against the experimental observations of gas-liquid spontaneous imbibition. The good match above indicates the newly proposed model can show the water saturation profile at a macroscopic scale while capture the underlying physics of the multiphase flow in a porous medium at a microscopic scale. Simulation results obtained from this model indicate that both wettability and viscosity ratio can affect the sequence of fluid imbibition into pores of different sizes during the multiphase flow, where less-viscous wetting fluid is preferentially imbibed into larger pores while more-viscous wetting fluid tends to be imbibed into smaller pores. Furthermore, this model provides an avenue to calculate the imbibition rate in pores of different sizes during wettability alteration and capture the non-Darcy effect in micro-and nano-scale pores.
基金supported by the National Natural Science Foundation of China (Grant No.51805086)。
文摘Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property entangled porous metallic wire materials(EPMWM),this paper designed a composite buffer which uses EPMWM and viscous fluid as cushioning materials under the low-speed impact of the recoil force device of weapon equipment(such as artillery,mortar,etc.).Combined with the capillary model,porosity,hydraulic diameter,maximum pore diameter and pore distribution were used to characterize the pore structure characteristics of EPMWM.The calculation model of the damping force of the composite buffer was established.The low-speed impact test of the composite buffer was conducted.The parameters of the buffer under low-speed impact were identified according to the model,and the nonlinear model of damping force was obtained.The test results show that the composite buffer with EPMWM and viscous fluid can absorb the impact energy from the recoil movement effectively,and provide a new method for the buffer design of weapon equipment(such as artillery,mortar,etc.).
文摘Recent studies have underscored the significance of the capillary fringe in hydrological and biochemical processes.Moreover,its role in shallow waters is expected to be considerable.Traditionally,the study of groundwater flow has centered on unsaturated-saturated zones,often overlooking the impact of the capillary fringe.In this study,we introduce a steady-state two-dimensional model that integrates the capillary fringe into a 2-D numerical solution.Our novel approach employs the potential form of the Richards equation,facilitating the determination of boundaries,pressures,and velocities across different ground surface zones.We utilized a two-dimensional Freefem++finite element model to compute the stationary solution.The validation of the model was conducted using experimental data.We employed the OFAT(One_Factor-At-Time)method to identify the most sensitive soil parameters and understand how changes in these parameters may affect the behavior and water dynamics of the capillary fringe.The results emphasize the role of hydraulic conductivity as a key parameter influencing capillary fringe shape and dynamics.Velocity values within the capillary fringe suggest the prevalence of horizontal flow.By variation of the water table level and the incoming flow q0,we have shown the correlation between water table elevation and the upper limit of the capillary fringe.
基金Supported by Beijing Science and Technology Development Program(Medical and Pharmaceutical Science Project),No.7232200.
文摘BACKGROUND The intrapapillary capillary loop(IPCL)characteristics,visualized using magnifying endoscopy,are commonly assessed for preoperative evaluation of the infiltration depth of esophageal squamous cell carcinoma(ESCC).Japan Esophageal Society(JES)classification is the most widely used classification.Microvascular structural changes are evaluated by magnifying endoscopy for the presence or absence of each morphological factor:tortuosity,dilatation,irregular caliber,and different shapes.However,the pathological characteristics of IPCLs have not been thoroughly investigated,especially the microvascular structures corresponding to the deepest parts of the lesions'infiltration.AIM To investigate differences in pathological microvascular structures of ESCC,which correspond to the deepest parts of the lesions'infiltration.METHODS Patients with ESCC and precancerous lesions diagnosed at Peking University Third Hospital were enrolled between January 2019 and April 2023.Patients first underwent magnified endoscopic examination,followed by endoscopic submucosal dissection or surgical treatment.Pathological images were scanned using a threedimensional slice scanner,and the pathological structural differences in different types,according to the JES classification,were analyzed using nonparametric tests and t-tests.RESULTS The 35 lesions were divided into four groups according to the JES classification:A,B1,B2,and B3.Statistical analyses revealed significant differences(aP<0.05)in the short and long calibers,area,location,and density between types A and B.Notably,there were no significant differences in these parameters between types B1 and B2 and between types B2 and B3(P>0.05).However,significant differences in the short calibers,long calibers,and area of IPCL were observed between types B1 and B3(aP<0.05);no significant differences were found in the density or location(P>0.05).CONCLUSION Pathological structures of IPCLs in the deepest infiltrating regions differ among various IPCL types classified by the JES classification under magnifying endoscopy,especially between the types A and B.
文摘Purpose: To evaluate optical coherence tomography angiography (OCT-A) data obtained from the superficial retinal capillary plexus of patients with retinal vein occlusion and comparative analysis with data registered from unaffected fellow eyes. Methods: The examined patients were classified into 2 groups: group 1—eyes with established retinal vein occlusion (n = 29) and group 2—unaffected fellow eyes of patients with retinal vein occlusion (n = 24). The scanning protocol “Angiography 3 × 3 mm” of Zeiss Cirrus HD-OCT 6000, AngioPlex Metrix was used to evaluate the retinal superficial capillary plexus. The analyzed parameters were vascular density and perfusion density, as well as the area, perimeter, and circularity of the foveolar avascular zone (FAZ). Results: The comparative analysis of FAZ parameters at the superficial capillary plexus (SCP) between group 1 (eyes with retinal vein occlusion) and group 2 (unaffected fellow eyes) showed significant results for the three parameters, respectively area (p = 0.003), perimeter (p ≤ 0.001), and circularity (p = 0.011) of FAZ. The comparative analysis of the vascular network at SCP in patients with diagnosed retinal vein occlusion and unaffected fellow eyes showed significant results for vascular density (VD) in the central (p = 0.038) and inner (p ≤ 0.001) zones as well as total VD (p ≤ 0.001) were statistically significant. Moreover, the results obtained in the study of vascular perfusion (VP) indicated significant results in the inner zone (p ≤ 0.001) and total VP (p = 0.001). Vascular perfusion in the central zone (p = 0.116) was the only parameter not to meet significant results. Conclusion: The current study observed a significant enlargement of the FAZ and loss of its circularity, along with a reduction in vascular network parameters at the superficial retinal capillary plexus level.
基金This study was funded by the Project of National Natural Science Foundation of China(Grant No.:82003705)the Shanghai Science and Technology Innovation Foundation(Grant Nos.:23010500200 and 23ZR1422700).
文摘Capillary electrochromatography(CEC)plays a significant role in chiral separation via the double separation principle,partition coefficient difference between the two phases,and electroosmotic flow-driven separation.Given the distinct properties of the inner wall stationary phase(SP),the separation ability of each SP differs from one another.Particularly,it provides large room for promising applications of open tubular capillary electrochromatography(OT-CEC).We divided the OT-CEC SPs developed over the past four years into six types:ionic liquids,nanoparticle materials,microporous materials,biomaterials,non-nanopolymers,and others,to mainly introduce their characteristics in chiral drug separation.There also added a few classic SPs that occurred within ten years as supplements to enrich the features of each SP.Additionally,we discuss their applications in metabolomics,food,cosmetics,environment,and biology as analytes in addition to chiral drugs.OT-CEC plays an increasingly significant role in chiral separation and may promote the development of capillary electrophoresis(CE)combined with other instruments in recent years,such as CE with mass spectrometry(CE/MS)and CE with ultraviolet light detector(CE/UV).
基金the National Key R&D Program of China(Nos.2022YFA1603802 and 2017YFA0403000)1W2B and 4B9A at the Beijing Synchrotron Radiation Facility.
文摘In certain exceptional cases,capillary samples must be used to measure X-ray absorption spectra(XAS).However,the inho-mogeneous thickness of capillary samples causes XAS distortion.This study discusses the distortion and correction of the XAS curve caused by the inhomogeneous thickness of capillary samples.The relationship between the distorted XAS curveμ′d_(eq)(measured values)and the real absorption coefficientμ_(s)d_(eq)(true values)of the sample was established.The distortion was slight and negligible when the vertical size(2h)of the X-ray beam spot was smaller than 60%of the capillary tube’s inner diameter(2R_(in)).When h/R_(in)>1,X-ray leakage is inevitable and should be avoided during measurement.Partial X-ray leakage caused by an X-ray beam spot size larger than the inner diameter of the capillary tube leads to serious compressed distortion of the XAS curve.When h/R_(in)<1,the distorted XAS data were well corrected.Possible errors and their influence on the corrected XAS are also discussed.Simulations and corrections for distortions verify the feasibility and effectiveness of the corrected method.
基金the National Natural Science Foundation of China(Grant Nos.:82273885,82073808 and 81872828).
文摘Here,a styrene-based polymer monolithic column poly(VBS-co-TAT-co-AHM)with reversed-phase/hydrophilic interaction liquid chromatography(RPLC/HILIC)bifunctional separation mode was success-fully prepared for capillary electrochromatography by the in situ polymerization of sodium p-styrene sulfonate(VBS)with cross-linkers 3-(acryloyloxy)-2-hydroxypropyl methacrylate(AHM)and 1,3,5-triacryloylhexahydro-1,3,5-triazine(TAT).The preparation conditions of the monolith were optimized.The morphology and formation of the poly(VBS-co-TAT-co-AHM)monolith were confirmed by scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).The separation perfor-mances of the monolith were evaluated systematically.It should be noted that the incorporation of VBS functional monomer can provideπ-πinteractions,hydrophilic interactions,and ion-exchange in-teractions.Hence,the prepared poly(VBS-co-TAT-co-AHM)monolith can achieve efficient separation of thiourea compounds,benzene series,phenol compounds,aniline compounds and sulfonamides in RPLC or HILIC separation mode.The largest theoretical plate number for N,N0-dimethylthiourea reached 1.7×10^(5)plates/m.In addition,the poly(VBS-co-TAT-co-AHM)monolithic column showed excellent reproducibility and stability.This novel monolithic column has great application value and potential in capillary electrochromatography(CEC).
文摘Objective:Cardiopulmonary resuscitation(CPR)after cardiac arrest(CA)is one of the main causes of capillary leakage syndrome(CLS).This study aimed to establish a stable CLS model following the CA and cardiopulmonary resuscitation(CA-CPR)model in Sprague-Dawley(SD)rats.Methods:We conducted a prospective,randomized,animal model study.All adult male SD rats were randomly divided into a normal group(group N),a sham operation group(group S),and a cardiopulmonary resuscitation group(group T).The SD rats of the three groups were all inserted with 24-G needles through their left femoral arteries and right femoral veins.In group S and group T,the endotracheal tube was intubated.In group T,CA induced by asphyxia(AACA)was caused by vecuronium bromide with the endotracheal tube obstructed for 8 min,and the rats were resuscitated with manual chest compression and mechanical ventilation.Preresuscitation and postresuscitation measurements,including basic vital signs(BVS),blood gas analysis(BG),routine complete blood count(CBC),wet-to-dry ratio of tissues(W/D),and the HE staining results after 6 h were evaluated.Results:In group T,the success rate of the CA-CPR model was 60%(18/30),and CLS occurred in 26.6%(8/30)of the rats.There were no significant differences in the baseline characteristics,including BVS,BG,and CBC,among the three groups(P>0.05).Compared with pre-asphyxia,there were significant differences in BVS,CBC,and BG,including temperature,oxygen saturation(SpO_(2)),mean arterial pressure(MAP),central venous pressure(CVP),white blood cell count(WBC),hemoglobin,hematocrit,pH,pCO_(2),pO_(2),SO_(2),lactate(Lac),base excess(BE),and Na+(P<0.05)after the return of spontaneous circulation(ROSC)in group T.At 6 h after ROSC in group T and at 6 h after surgery in groups N and S,there were significant differences in temperature,heart rate(HR),respiratory rate(RR),SpO_(2),MAP,CVP,WBC,pH,pCO_(2),Na+,and K+among the three groups(P<0.05).Compared with the other two groups,the rats in group T showed a significantly increased W/D weight ratio(P<0.05).The HE-stained sections showed consistent severe lesions in the lung,small intestine,and brain tissues of the rats at 6 h after ROSC following AACA.Conclusion:The CA-CPR model in SD rats induced by asphyxia could reproduce CLS with good stability and reproducibility.
基金Project supported by the National Key Research and Development Program of China(Grant No.2021YFF0701202)the National Natural Science Foundation of China(Grant No.11875087)。
文摘Glancing incidence x-ray fluorescence spectrometry using a single-bounce parabolic capillary is proposed for the analysis of layered samples.The divergence of the x-ray beam was 0.33 mrad.In this paper,we used this instrumental setup to analyze a Si single crystal and a 50 nm HfO_(2) single-layer film deposited on a Si substrate.
基金by the Program for Professor of Special Appointment(Eastern Scholar,No.TP2020009)at Shanghai Institutions of Higher Learning。
文摘We provide the capillary pressure curves p_(c)(s)as a function of the effective saturation s based on the theoretical framework of upscaling unsaturated flows in vertically heterogeneous porous layers proposed recently(Z.Zheng,Journal of Fluid Mechanics,950,A17,2022).Based on the assumption of vertical gravitational-capillary equilibrium,the saturation distribution and profile shape of the invading fluid can be obtained by solving a nonlinear integral-differential equation.The capillary pressure curves p_(c)(s)can then be constructed by systematically varying the injection rate.Together with the relative permeability curves k_(rn)(s)that are already obtained.One can now provide quick estimates on the overall behaviours of interfacial and unsaturated flows in vertically-heterogeneous porous layers.
基金Supported by the National Natural Science Foundation of China(U2003102,41974117)China National Science and Technology Major Project(2016ZX05052001).
文摘According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivalent capillary pressure curve(pe)were established to reflect the reservoir heterogeneity.To promote the application of the theoretical models,the Archie's equation was introduced to establish a general model for quantitatively characterizing bi,K,and pei.Compared with the existing models,it is shown that:(1)the existing porosity spectrum model is the same as the general equation of gi;(2)the Ki model can display the permeability spectrum as compared with Purcell's permeability model;(3)the per model is constructed on a theoretical basis and avoids the limitations of existing models that are built only based on the component of porosity spectrum,as compared with the empirical model of capillary pressure curve.The application in the Permian Maokou Formation of Well TsX in the Central Sichuan paleo-uplift shows that the Ф_(i),K_(i),and p_(ci) models can be effectively applied to the identification of reservoir types,calculation of reservoir properties and pore structure parameters,and evaluation of reservoir heterogeneity.
文摘The interphase mass,heat transfer efficiency,and flow resistance are strongly dependent on bubble size in gas-liquid two-phase systems,so it is very important for engineering applications to effectively control bubble size.In this paper,the formation,growth,and detachment of single bubbles in Newtonian liquids based on capillary needles were studied in detail using a volume of fluid method.The authors investigated the effects of gas injection velocity,gravitational level,surface tension coefficient,needle radius,and liquid-phase properties(liquid viscosity and density)on the process of bubble generation,and the effects of the above factors on bubble shape,detachment diameter,and time were analyzed.The results show that an increase in gas injection rate,liquid-phase viscosity,needle radius,and surface tension coefficient can lead to an increase in bubble detachment diameter;however,an increase in liquid-phase density and gravitational level can lead to a decrease in bubble detachment diameter.It is found that the effect of the liquid-phase viscosity on bubble detachment diameter and time is slight,but the effect of gravitational level on detachment diameter and time is significant.Among all the forces,buoyancy,surface tension,and pressure are the most important ones that control the generation of bubbles.
基金the fund of the Chinese Academy of Geological Sciences (YYWF201624)。
文摘In this paper, the plexiglass experimental column was used to analyze the capillary fringe thickness of three kinds of lithologies-silty sand, silt and silty clay-providing a basis for defining the interface in the study of hydrodynamics at the water table between vandose water and groundwater. The capillary fringe generally refers to the subsurface layer in which the groundwater seeps up to the air-entry suction value due to capillary action, and is nearly saturated with water. The thickness of the capillary fringe varies with different lithologies. In this experiment, self-made stable water supply devices were used to study the height of capillary rise, capillary water volume and capillary fringe thickness of the three lithologies through capillary experiment and numerical simulation. Experimental results show as follows:(1) Rising height of capillary water is related to time, particle radius, volume, etc., and the relationship between height and time is in line with the Hill model.(2) The smaller the particle radius, the more water the pores contain, and the ratio of the unsaturated portion of capillary water to the total water content gradually rises. Experimental results obtained by numerical simulation, segmentation and actual measurement are consistent.(3) The thickness of the capillary zone is related to the lithology. The larger the particle size, the smaller the thickness of the capillary fringe, and vice versa. In silty sand, the thickness measures about 13 cm. The figure rises to 16 cm in silt, and 37 cm in silty clay. This work studies the law of soil water transport at saturated-unsaturated interface. Experimental results are of great significance to the study of soil water and salt transport and soil salinization control in unsaturated zone.
基金Project(51374035)supported by the National Natural Science Foundation of ChinaProject(201351)supported by the Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject(NCET-13-0669)supported by Program for New Century Excellent Talents in University,China
文摘The capillary process coexists with gravity flow within leaching heap due to the dual-porosity structure. Capillary rise is responsible for the mineral dissolution in fine particle zones and interior coarse rock. The effect of particle size and heap porosity on the capillary process was investigated through a series of column tests. Macropore of the ore heap was identified, and its capillary rise theory analysis was put forward. Two groups of ore particles, mono-size and non-uniform, were selected for the capillary rise test. The result shows that particle size has an inverse effect on the capillary ultimate height, and smaller particles exhibit higher capillary rise. Meanwhile, the poorly graded group exhibits small rise height and velocity, while the capillary rise in the well-graded particles is much greater. The relationship between porosity and fitting parameters of capillary rise was obtained. Low porosity and high surface tension lead to higher capillary height of the fine gradation. Moisture content increases with the capillary rise level going up, the relationship between capillary height and moisture content was obtained.
文摘Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products （CB-1, CB-2） from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.
