Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By us...Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By using dynamic light scattering(DLS),we discovered a dynamical transition for charged ring polymers with increasing ring concentration in the gel matrix from a diffusive state to a non-diffusive topological frustrated state with a more compact conformation.When the ring polymer size is smaller than the mesh size of the gel matrix,the rings are diffusive at low concentration of 5 g/L.The ring diffusion coefficient in the gel matrix is an order of magnitude smaller than that of rings in solution,obeying the Ogston's model.At high ring concentration of 40 g/L,the collective dynamical behavior of the charged rings exhibits a topologically frustrated non-diffusive state,which may originate from the inter-ring threading with the external confinement from the gel matrix.Based on our previous theoretical work,we also conjectured that in such a non-diffusive state,the ring polymers might adopt a more compact conformation with the overall size exponentν=1/3.展开更多
The classification and application of dynamic lighting based on lighting sources by using LED and fluorescent lamp and photochemistry with ultraviolet light and without ultraviolet light are discussed. The origin of d...The classification and application of dynamic lighting based on lighting sources by using LED and fluorescent lamp and photochemistry with ultraviolet light and without ultraviolet light are discussed. The origin of dynamic lighting based on fluorescent lamp is introduced. The reason for the use of LED which stands for light emitting diodes in dynamic lighting is also described. The effect of dynamic lighting on the human body in terms of cortisol and melatonin production,alertness,body temperature,and mood is reviewed. The standard about ultraviolet light is also introduced. In this paper,an ideal dynamic lighting is proposed. The CRI,CCT,illuminance,spectrum,and dynamism are considered in this type of ideal dynamic lighting.展开更多
Understanding the dynamic assembly process of DNA nanostructures is important for developing novel strategy to design and construct functional devices.In this work,temperature-controlled dynamic light scattering(DLS)s...Understanding the dynamic assembly process of DNA nanostructures is important for developing novel strategy to design and construct functional devices.In this work,temperature-controlled dynamic light scattering(DLS)strategy has been applied to study the global assembly process of DNA origami and DNA bricks.Through the temperature dependent size and intensity profiles,the self-assembly process of various DNA nanostructures with different morphologies have been well-studied and the temperature transition ranges could be observed.Taking advantage of the DLS information,rapid preparation of the DNA origami and the brick assembly has been realized through a constant temperature annealing.Our results demonstrate that the DLS-based strategy provides a convenient and robust tool to study the dynamic process of forming hieratical DNA structures,which will benefit understanding the mechanism of self-assembly of DNA nanostructures.展开更多
Objective Size distribution is an important biophysical property of extracellular vesicles(EVs).EVs include small EVs(s-EVs)and large EVs(l-EVs)by size.Differential ultracentrifugation(dUC)is widely used to separate E...Objective Size distribution is an important biophysical property of extracellular vesicles(EVs).EVs include small EVs(s-EVs)and large EVs(l-EVs)by size.Differential ultracentrifugation(dUC)is widely used to separate EVs from biofluids,but it can precipitate large impurity particles.Dynamic light scattering(DLS)is a simple and fast method for analyzing the size distribution of EVs.However,this approach is nonideal for heterogeneous and polydisperse samples since a small quantity of large impurity particles can markedly disturb the DLS results.Here,we developed a simple method to improve the reliability of DLS measurements.Methods Plasma was obtained from 13 volunteers.The plasma was first processed by dUC to obtain crude l-EVs.The crude l-EVs were filtered with syringe filters(pore size of 1μm and membrane material of hydrophilic polyvinylidene fluoride(PVDF))to remove large impurity particles from l-EVs.The size distributions of the crude l-EVs and filtered l-EVs were measured via DLS.Results After the samples were filtered,the coefficients of variation of the hydrodynamic radius and Peak 1 intensity of the filtered l-EVs decreased from 20.39%(12.76–28.96%)and 20.44%(14.58–28.32%)to 3.05%(1.79–4.72%)and 3.43%(1.76–5.88%),respectively,compared with those of the crude l-EVs.Conclusion These findings suggest that filtration can effectively separate circulating l-EVs in plasma to remove large impurity particles and make samples suitable for characterization by DLS.Our findings provide a simple method to improve precision via DLS to measure the size distribution of EVs.展开更多
Natural surfactants that are present in complex crude oil may induce spontaneous emulsification in the oil and brine phases that co-exist in rock pores.This process is known to be affected by the salinity of brine.How...Natural surfactants that are present in complex crude oil may induce spontaneous emulsification in the oil and brine phases that co-exist in rock pores.This process is known to be affected by the salinity of brine.However,the role of salinity in water-oil micro-emulsification is not fully understood.In this paper,we report on our experimental studies of the effect of salinity on spontaneous emulsification in a“mixture”of dodecane and brine.The dodecane contains SPAN 80 surfactant and brine with different salinity values,varying from 0.2%to 20%(by weight).For our observations,we use dynamic light scattering(DLS)technique to capture nano-scale emulsion formation and pendant drop method to observe micro-scale emulsion dynamics.The DLS experiments show that small(2.2 nm)and medium-sized emulsions(100 nm)are formed at low salinities,while at higher salinities only smaller droplets are formed and emulsification is reduced.In pendant drop experiments,dodecane and heptane systems were tested over 13 h.Heptane exhibited faster emulsification at water-oil interfaces in the cases with pure water and low salinity brine(0.2%),where the changes at interfacial area occurring within two hours and significant droplet shrinkage by 13 h.Lower salinity enhances micelle activity and emulsification,while higher salinities(2%,5%,and 20%)stabilize the oil-water interface and suppress emulsion formation.Dodecane exhibits a similar trend in emulsification but forms more stable emulsions and maintains a more stable water-oil interface compared to heptane.Additionally,we present the theory of reverse micelle exclusion through a theoretical derivation,providing a deeper understanding of the emulsification mechanism.Four distinct scenarios are schematically presented to explain the influence of salinity on spontaneous emulsification,illustrating how varying salinity levels affect micelle formation and emulsion behaviour.This study provides valuable insights into optimizing salinity levels in enhanced oil recovery.展开更多
Background Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light （DL） could reset the circadian rhythm by activation of the suprachi...Background Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light （DL） could reset the circadian rhythm by activation of the suprachiasmatic nucleus to prevent delirium. Evidence regarding the effects of light therapy is predominantly focused on psychiatric disorders and circadian rhythm sleep disorders. In this study, we investi- gated the effect of DL on the total hospital length of stay （LOS） and occurrence of delirium in patients admitted to the Coronary Care Unit （CCU）. Methods This was a retrospective cohort study. Patients older than 18 years, who were hospitalized longer than 12 h at the CCU and had a total hospital LOS for at least 24 h, were included. Patients were assigned to a room with DL （n = 369） or regular lighting condi- tions （n = 379）. DL was administered at the CCU by two ceiling-mounted light panels delivering light with a colour temperature between 2700 and 6500 degrees Kelvin. Reported outcome data were： total hospital LOS, delirium incidence, consultation of a geriatrician and the amount of prescripted antipsychotics. Results Between May 2015 and May 2016, data from 748 patients were collected. Baseline charac- teristics, including risk factors provoking delirium, were equal in both groups. Median total hospital LOS in the DL group was 100.5 （70.8-186.0） and 101.0 （73.0-176.4） h in the control group （P = 0.935）. The incidence of delirium in the DL and control group was 5.4% （20/369） and 5.0% （19/379）, respectively （P = 0.802）. No significant differences between the DL and control group were observed in secon- dary endpoints. Subgroup analysis based on age and CCU LOS also showed no differences. Conclusion Our study suggests exposure to DL as an early single approach does not result in a reduction of total hospital LOS or reduced incidence of delirium. When delirium was diagnosed, it was associated with poor hospital outcome.展开更多
A novel method combining visualization particle tracking with image-based dynamic light scattering was developed to achieve the in situ and real-time size measurement of nanobubbles(NBs).First,the in situ size distrib...A novel method combining visualization particle tracking with image-based dynamic light scattering was developed to achieve the in situ and real-time size measurement of nanobubbles(NBs).First,the in situ size distribution of NBs was visualized by dark-field microscopy.Then,real-time size during the preparation was measured using image-based dynamic light scattering,and the longitudinal size distribution of NBs in the sample cell was obtained in a steady state.Results show that this strategy can provide a detailed and accurate size of bubbles in the whole sample compared with the commercial ZetaSizer Nano equipment.Therefore,the developed method is a real-time and simple technology with excellent accuracy,providing new insights into the accurate measurement of the size distribution of NBs or nanoparticles in solution.展开更多
Dynamic behaviors on polyacrylic acid (PAA) gels and mass (small molecules) transports in the gels have been studied mainly by dynamic light scattering (DLS). The cross-linking degree (fc), monomer concentration (Cm)...Dynamic behaviors on polyacrylic acid (PAA) gels and mass (small molecules) transports in the gels have been studied mainly by dynamic light scattering (DLS). The cross-linking degree (fc), monomer concentration (Cm) and temperature of the gels have significant influences on its dynamic behavior and mass transport in the gels. The increase of fc leads to decrease of the mesh sizes of the gels, thus the obstacle of the gels for mass transport is increased. As a result, small molecular diffusion Dk in the gels is decreased. So even if for small molecules, the Dk also is influenced.展开更多
The spontaneous formation of vesicles in the aqueous of cationic surfactant phosphate (PTA) and anionic surfactant sodium dodecyl sulfate (SDS) at certain mixing ratios have obtained1. The addition of urea or NaI will...The spontaneous formation of vesicles in the aqueous of cationic surfactant phosphate (PTA) and anionic surfactant sodium dodecyl sulfate (SDS) at certain mixing ratios have obtained1. The addition of urea or NaI will expand the range of spontaneous vesicle formation. The fact is demonstrated by negative-staining transmission electron microscope(TEM) and dynamic light scattering(DLS) methods. The phenomenon especially in the part of urea is reported by us at first. Mechanism of urea/NaI–induced vesicles formation is discussed from the viewpoint of the molecular geometry packing parameter f, conformation and interaction.展开更多
We analytically and numerically investigate a signal light storing mechanism based on the controllable electromagnetically induced transparency(EIT)effect.We demonstrate that the isolation between the waveguide and th...We analytically and numerically investigate a signal light storing mechanism based on the controllable electromagnetically induced transparency(EIT)effect.We demonstrate that the isolation between the waveguide and the cavities cannot be achieved instantly as soon as the two cavities are tuned into resonance,no matter the index tuning rate is ultrafast or slow.We also investigate the temporal evolution features of the intracavity energy when the pulse during time is prolonged.We find many periodical oscillations of the trapped energy in both cavities,and they are entirely complementary.Our analysis shows that the adiabatic wavelength conversion in both cavities and a phase difference π between them play critical roles in this phenomenon.展开更多
The technique of dynamic light scattering has been used to investigate the translation diffusion behavior of 8-arm star polystyrene (SPS)in a good solvent, tetrahydrofuran (THF) or benzene (BZ) and a theta solvent, cy...The technique of dynamic light scattering has been used to investigate the translation diffusion behavior of 8-arm star polystyrene (SPS)in a good solvent, tetrahydrofuran (THF) or benzene (BZ) and a theta solvent, cyclohexane (CH), by homodyne photon correlation spectroscopy .The intensityintensity autocorrelation function was analyzed by the method of cumulant. The translation diffusion coefficients have been obtained as a function of temperature and concentration. Under theta condition ,the non-concentration dependence of diffusion coefficient showed the unperturbed Gaussian state o the SPS molecular chain. The different hydrodynamic radii estimated from Stokes- Einstein equation reflected the stretch extent of the arm chain for regular star polymer. The data of diffusion activation energy of SPS in THF, BZ and CH were also obtained respectively.展开更多
Dynamic light scattering(DLS)is a promising technique for early cataract detection and for studying cataractogenesis.A novel probabilistic analysis tool,the sparse Bayesian learning(SBL)algorithm,is described for reco...Dynamic light scattering(DLS)is a promising technique for early cataract detection and for studying cataractogenesis.A novel probabilistic analysis tool,the sparse Bayesian learning(SBL)algorithm,is described for reconstructing the most-probable size distribution ofα-crystallin and their aggregates in an ocular lens from the DLS data.The performance of the algorithm is evaluated by analyzing simulated correlation data from known distributions and DLS data from the ocular lenses of a fetal calf,a Rhesus monkey,and a man,so as to establish the required efficiency of the SBL algorithm for clinical studies.展开更多
In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occ...In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occurrences. The multifaceted nature of these influences makes the surveillance of mass movements a highly intricate task, requiring an understanding of numerous interdependent variables. Recent years have seen an emergence in scholarly research aimed at integrating geophysical and geotechnical methodologies. The conjoint examination of geophysical and geotechnical data offers an enhanced perspective into subsurface structures. Within this work, a methodology is proposed for the synchronous analysis of electrical resistivity geophysical data and geotechnical data, specifically those extracted from the Light Dynamic Penetrometer (DPL) and Standard Penetration Test (SPT). This study involved a linear fitting process to correlate resistivity with N10/SPT N-values from DPL/SPT soundings, culminating in a 2D profile of N10/SPT N-values predicated on electrical profiles. The findings of this research furnish invaluable insights into slope stability by allowing for a two-dimensional representation of penetration resistance properties. Through the synthesis of geophysical and geotechnical data, this project aims to augment the comprehension of subsurface conditions, with potential implications for refining landslide risk evaluations. This endeavor offers insight into the formulation of more effective and precise slope management protocols and disaster prevention strategies.展开更多
Light-beam shifts accompanied by propagation between two media show potential in applications such as optical sensing,optical communication,and optical computing.However,existing work tends to focus on the static resp...Light-beam shifts accompanied by propagation between two media show potential in applications such as optical sensing,optical communication,and optical computing.However,existing work tends to focus on the static response of the device,i.e.,the beam shift when the structural parameters and incident conditions are fixed.Here,we analyze the dynamics of beam shifting via photonic crystal slabs under refractive index variation.On the one hand,we investigate the trend of cross-polarized phase gradient under small changes in refractive index.Simulation results show that the direction of the beam shift can change by more than 50°for a refractive index change of only 0.06.On the other hand,we study the interaction of incident light with the far-field polarizations of bound states in the continuum in the presence of a refractive index jump in the phase-change material.In this case,simulation results show that the large change in the Pancharatnam-Berry phase gradient causes the beam to move widely,with a change in beam direction of 61.30°and a change in beam displacement of 15μm.Furthermore,all displacement amounts are comparable to the radius of the incident beam(~8μm).Our work provides a new perspective on the study of beam shifts,which can advance practical applications of beam shift in sensing,intelligent detecting,and beam control.展开更多
Ultrafast tip-based microscopy has evolved to meet three critical parameters in optical characterization:spatial,spectral,and temporal resolution.This advancement provides deep insights into light-matter interactions ...Ultrafast tip-based microscopy has evolved to meet three critical parameters in optical characterization:spatial,spectral,and temporal resolution.This advancement provides deep insights into light-matter interactions in both real time and real space.In particular,it allows direct observation of polaritons,quantum states,and nonequilibrium dynamics,especially in low-dimensional quantum materials.展开更多
The nanometer cobalt blue pigments were prepared by microemulsion method. Using dynamic light scattering(DLS) test method, the influences of water content on the size of liquid drop of microemulsion and the liquid dro...The nanometer cobalt blue pigments were prepared by microemulsion method. Using dynamic light scattering(DLS) test method, the influences of water content on the size of liquid drop of microemulsion and the liquid drop of microemulsion on the final diameter of nanometer particle were studied in the course of preparation. Accordingly, the method to control the diameter of nanometer particle by changing water content was established. The nanometer cobalt blue particles were confirmed by XRD and TEM. Color parameters of pigments were determined. The quantum size effect of the pigments was discussed.展开更多
A modified seeded growth process of silica particles with a continuous addition of tetraethyl orthosilicate （TEOS） was presented to control the diameter of silica particles. The diameter of particles was monitored b...A modified seeded growth process of silica particles with a continuous addition of tetraethyl orthosilicate （TEOS） was presented to control the diameter of silica particles. The diameter of particles was monitored by dynamic light scattering to control the addition of TEOS. The increase in the diameter of the silica particles with time and the addition of TEOS was investigated. The diameter of silica seeds increased from 193 nm to 446 nm in 4 h. The final diameter of silica particles was tailored within the range of ±5 nm to the target diameter. Silica particles with diameter of 446 nm were synthesized and assembled into photonic crystals with a pseudo band gap centered at just 1000 nm. The feasibility and practicability of this modified seeded growth process was verified.展开更多
Specific ion effects(Hofmeister effects)have recently attracted the attention of soil scientists,and it has been found that ionic non-classic polarization plays an important role in the specific ion effect in soil.How...Specific ion effects(Hofmeister effects)have recently attracted the attention of soil scientists,and it has been found that ionic non-classic polarization plays an important role in the specific ion effect in soil.However,this explanation cannot be applied to H+.The aim of this work was to characterize the specific ion effect of H+on variably charged soil(yellow soil)colloid aggregation.The total average aggregation(TAA)rate,critical coagulation concentration(CCC),activation energy,and zeta potential were used to characterize and compare the specific ion effects of H+,K+,and Na+.Results showed that strong specific ion effects of H+,K+,and Na+existed in variably charged soil colloid aggregation.The TAA rate,CCC,and activation energy were sensitive to H+,and the addition of a small amount of H+changed the TAA rate,CCC,and activation energy markedly.The zeta potential results indicated that the specific ion effects of H+,K+,and Na+on soil colloid aggregation were caused by the specific ion effects of H+,K+,and Na+on the soil electric field strength.In addition,the origin of the specific ion effect for H+was its chemical adsorption onto surfaces,while those for alkali cations were non-classic polarization.This study indicated that H+,which occurs naturally in variably charged soils,will dominate variably charged soil colloid aggregation.展开更多
Spontaneous vesicles from the mixed aqueous solution of poly-tailed cationic surfactant PTA and anionic surfactant AOT are firstly obtained. Vesicle formation and characterizations are demonstrated by negative-staini...Spontaneous vesicles from the mixed aqueous solution of poly-tailed cationic surfactant PTA and anionic surfactant AOT are firstly obtained. Vesicle formation and characterizations are demonstrated by negative-staining TEM and dynamic light scattering. A monodisperse vesicle system is obtained with a polydispersity of 0.082. Ultrasonication can promote the vesicle formation. Mechanism of vesicle formation is discussed from the viewpoint of molecular interaction.展开更多
Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase b...Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase both in the use and application of the in situ tests: cone penetration test(CPT) and dynamic probing(DP). Several empirical SPT-CPT and dynamic probing light(DPL)-CPT correlations for sandy soils have been discussed in the literature. New SPT-CPT and DPL-CPT correlations for the sandy soils of the city of Vitoria, in the southeast of Brazil, are suggested in this paper. Statistical analyses to evaluate the quality of the data used are performed, and the suggested correlations are validated with several previous published datasets. The paper also provides some insights into SPT-CPT correlations and soil characteristics(i.e. the mean particle size and the fines fraction of the soil).展开更多
基金supported by the National Natural Science Foundation of China(No.22273114)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0770101)+1 种基金the National Key R&D Program of China(No.2023YFE0124500),the National Key R&D Program of China(No.2023YFC2411203)International Partnership Program of the Chinese Academy of Sciences(No.027GJHZ2022061FN)。
文摘Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By using dynamic light scattering(DLS),we discovered a dynamical transition for charged ring polymers with increasing ring concentration in the gel matrix from a diffusive state to a non-diffusive topological frustrated state with a more compact conformation.When the ring polymer size is smaller than the mesh size of the gel matrix,the rings are diffusive at low concentration of 5 g/L.The ring diffusion coefficient in the gel matrix is an order of magnitude smaller than that of rings in solution,obeying the Ogston's model.At high ring concentration of 40 g/L,the collective dynamical behavior of the charged rings exhibits a topologically frustrated non-diffusive state,which may originate from the inter-ring threading with the external confinement from the gel matrix.Based on our previous theoretical work,we also conjectured that in such a non-diffusive state,the ring polymers might adopt a more compact conformation with the overall size exponentν=1/3.
基金Social Science and Technology Development Project in Dong Guan-Model LED light source for plant growth.
文摘The classification and application of dynamic lighting based on lighting sources by using LED and fluorescent lamp and photochemistry with ultraviolet light and without ultraviolet light are discussed. The origin of dynamic lighting based on fluorescent lamp is introduced. The reason for the use of LED which stands for light emitting diodes in dynamic lighting is also described. The effect of dynamic lighting on the human body in terms of cortisol and melatonin production,alertness,body temperature,and mood is reviewed. The standard about ultraviolet light is also introduced. In this paper,an ideal dynamic lighting is proposed. The CRI,CCT,illuminance,spectrum,and dynamism are considered in this type of ideal dynamic lighting.
基金supported by the National Natural Science Foundation of China(No.21971248)。
文摘Understanding the dynamic assembly process of DNA nanostructures is important for developing novel strategy to design and construct functional devices.In this work,temperature-controlled dynamic light scattering(DLS)strategy has been applied to study the global assembly process of DNA origami and DNA bricks.Through the temperature dependent size and intensity profiles,the self-assembly process of various DNA nanostructures with different morphologies have been well-studied and the temperature transition ranges could be observed.Taking advantage of the DLS information,rapid preparation of the DNA origami and the brick assembly has been realized through a constant temperature annealing.Our results demonstrate that the DLS-based strategy provides a convenient and robust tool to study the dynamic process of forming hieratical DNA structures,which will benefit understanding the mechanism of self-assembly of DNA nanostructures.
基金National Natural Science Foundation of China(No.82495171,92268202,82270485)National Key R&D Program of China(No.2021YFA0805100)+5 种基金Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(No.2023-PT320-03)Guangdong Basic and Applied Basic Research Foundation,China(No.2024A1515030041)The Science and Technology Planning Project of Guangdong Province,(No.2023B1212060018)Sun Yat-sen University Basic Research Funds(No.24qnpy354)Clinical Research 5010 Program(No.2014002)Program of National Key Clinical Specialties.
文摘Objective Size distribution is an important biophysical property of extracellular vesicles(EVs).EVs include small EVs(s-EVs)and large EVs(l-EVs)by size.Differential ultracentrifugation(dUC)is widely used to separate EVs from biofluids,but it can precipitate large impurity particles.Dynamic light scattering(DLS)is a simple and fast method for analyzing the size distribution of EVs.However,this approach is nonideal for heterogeneous and polydisperse samples since a small quantity of large impurity particles can markedly disturb the DLS results.Here,we developed a simple method to improve the reliability of DLS measurements.Methods Plasma was obtained from 13 volunteers.The plasma was first processed by dUC to obtain crude l-EVs.The crude l-EVs were filtered with syringe filters(pore size of 1μm and membrane material of hydrophilic polyvinylidene fluoride(PVDF))to remove large impurity particles from l-EVs.The size distributions of the crude l-EVs and filtered l-EVs were measured via DLS.Results After the samples were filtered,the coefficients of variation of the hydrodynamic radius and Peak 1 intensity of the filtered l-EVs decreased from 20.39%(12.76–28.96%)and 20.44%(14.58–28.32%)to 3.05%(1.79–4.72%)and 3.43%(1.76–5.88%),respectively,compared with those of the crude l-EVs.Conclusion These findings suggest that filtration can effectively separate circulating l-EVs in plasma to remove large impurity particles and make samples suitable for characterization by DLS.Our findings provide a simple method to improve precision via DLS to measure the size distribution of EVs.
基金the funding from National Natural Science Foundation of China(Grant No.52474105).
文摘Natural surfactants that are present in complex crude oil may induce spontaneous emulsification in the oil and brine phases that co-exist in rock pores.This process is known to be affected by the salinity of brine.However,the role of salinity in water-oil micro-emulsification is not fully understood.In this paper,we report on our experimental studies of the effect of salinity on spontaneous emulsification in a“mixture”of dodecane and brine.The dodecane contains SPAN 80 surfactant and brine with different salinity values,varying from 0.2%to 20%(by weight).For our observations,we use dynamic light scattering(DLS)technique to capture nano-scale emulsion formation and pendant drop method to observe micro-scale emulsion dynamics.The DLS experiments show that small(2.2 nm)and medium-sized emulsions(100 nm)are formed at low salinities,while at higher salinities only smaller droplets are formed and emulsification is reduced.In pendant drop experiments,dodecane and heptane systems were tested over 13 h.Heptane exhibited faster emulsification at water-oil interfaces in the cases with pure water and low salinity brine(0.2%),where the changes at interfacial area occurring within two hours and significant droplet shrinkage by 13 h.Lower salinity enhances micelle activity and emulsification,while higher salinities(2%,5%,and 20%)stabilize the oil-water interface and suppress emulsion formation.Dodecane exhibits a similar trend in emulsification but forms more stable emulsions and maintains a more stable water-oil interface compared to heptane.Additionally,we present the theory of reverse micelle exclusion through a theoretical derivation,providing a deeper understanding of the emulsification mechanism.Four distinct scenarios are schematically presented to explain the influence of salinity on spontaneous emulsification,illustrating how varying salinity levels affect micelle formation and emulsion behaviour.This study provides valuable insights into optimizing salinity levels in enhanced oil recovery.
文摘Background Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light （DL） could reset the circadian rhythm by activation of the suprachiasmatic nucleus to prevent delirium. Evidence regarding the effects of light therapy is predominantly focused on psychiatric disorders and circadian rhythm sleep disorders. In this study, we investi- gated the effect of DL on the total hospital length of stay （LOS） and occurrence of delirium in patients admitted to the Coronary Care Unit （CCU）. Methods This was a retrospective cohort study. Patients older than 18 years, who were hospitalized longer than 12 h at the CCU and had a total hospital LOS for at least 24 h, were included. Patients were assigned to a room with DL （n = 369） or regular lighting condi- tions （n = 379）. DL was administered at the CCU by two ceiling-mounted light panels delivering light with a colour temperature between 2700 and 6500 degrees Kelvin. Reported outcome data were： total hospital LOS, delirium incidence, consultation of a geriatrician and the amount of prescripted antipsychotics. Results Between May 2015 and May 2016, data from 748 patients were collected. Baseline charac- teristics, including risk factors provoking delirium, were equal in both groups. Median total hospital LOS in the DL group was 100.5 （70.8-186.0） and 101.0 （73.0-176.4） h in the control group （P = 0.935）. The incidence of delirium in the DL and control group was 5.4% （20/369） and 5.0% （19/379）, respectively （P = 0.802）. No significant differences between the DL and control group were observed in secon- dary endpoints. Subgroup analysis based on age and CCU LOS also showed no differences. Conclusion Our study suggests exposure to DL as an early single approach does not result in a reduction of total hospital LOS or reduced incidence of delirium. When delirium was diagnosed, it was associated with poor hospital outcome.
基金The National Key Research and Development Program of China(No.2017YFA0104302)the National Natural Science Foundation of China(No.51832001,61821002,81971750).
文摘A novel method combining visualization particle tracking with image-based dynamic light scattering was developed to achieve the in situ and real-time size measurement of nanobubbles(NBs).First,the in situ size distribution of NBs was visualized by dark-field microscopy.Then,real-time size during the preparation was measured using image-based dynamic light scattering,and the longitudinal size distribution of NBs in the sample cell was obtained in a steady state.Results show that this strategy can provide a detailed and accurate size of bubbles in the whole sample compared with the commercial ZetaSizer Nano equipment.Therefore,the developed method is a real-time and simple technology with excellent accuracy,providing new insights into the accurate measurement of the size distribution of NBs or nanoparticles in solution.
基金Project 29774011 was supported by the National Natural Science Foundation of China.
文摘Dynamic behaviors on polyacrylic acid (PAA) gels and mass (small molecules) transports in the gels have been studied mainly by dynamic light scattering (DLS). The cross-linking degree (fc), monomer concentration (Cm) and temperature of the gels have significant influences on its dynamic behavior and mass transport in the gels. The increase of fc leads to decrease of the mesh sizes of the gels, thus the obstacle of the gels for mass transport is increased. As a result, small molecular diffusion Dk in the gels is decreased. So even if for small molecules, the Dk also is influenced.
基金This work supported by the National Natural Science Foundation of China(No.30370945)Ministry of Science and Technology(G 2000078104,2003CCA02900)+2 种基金Guizhou Provincial Govemor Foundation(No.6,2001)Guizhou Education Department(No.206,2003)Guizhou Normal University Young Teachers Development Scientific Research Found.
文摘The spontaneous formation of vesicles in the aqueous of cationic surfactant phosphate (PTA) and anionic surfactant sodium dodecyl sulfate (SDS) at certain mixing ratios have obtained1. The addition of urea or NaI will expand the range of spontaneous vesicle formation. The fact is demonstrated by negative-staining transmission electron microscope(TEM) and dynamic light scattering(DLS) methods. The phenomenon especially in the part of urea is reported by us at first. Mechanism of urea/NaI–induced vesicles formation is discussed from the viewpoint of the molecular geometry packing parameter f, conformation and interaction.
基金Project supported by the National Natural Science Foundation of China(Grant No.11774098)the Guangdong Natural Science Foundation(Grant Nos.2022A1515011950 and 2023A1515010781)the Science and Technology Program of Guangzhou(Grant No.202002030500)。
文摘We analytically and numerically investigate a signal light storing mechanism based on the controllable electromagnetically induced transparency(EIT)effect.We demonstrate that the isolation between the waveguide and the cavities cannot be achieved instantly as soon as the two cavities are tuned into resonance,no matter the index tuning rate is ultrafast or slow.We also investigate the temporal evolution features of the intracavity energy when the pulse during time is prolonged.We find many periodical oscillations of the trapped energy in both cavities,and they are entirely complementary.Our analysis shows that the adiabatic wavelength conversion in both cavities and a phase difference π between them play critical roles in this phenomenon.
文摘The technique of dynamic light scattering has been used to investigate the translation diffusion behavior of 8-arm star polystyrene (SPS)in a good solvent, tetrahydrofuran (THF) or benzene (BZ) and a theta solvent, cyclohexane (CH), by homodyne photon correlation spectroscopy .The intensityintensity autocorrelation function was analyzed by the method of cumulant. The translation diffusion coefficients have been obtained as a function of temperature and concentration. Under theta condition ,the non-concentration dependence of diffusion coefficient showed the unperturbed Gaussian state o the SPS molecular chain. The different hydrodynamic radii estimated from Stokes- Einstein equation reflected the stretch extent of the arm chain for regular star polymer. The data of diffusion activation energy of SPS in THF, BZ and CH were also obtained respectively.
基金the National Science Council of the Republic of China under the Contract No.NSC-97-2112-M-006-006.
文摘Dynamic light scattering(DLS)is a promising technique for early cataract detection and for studying cataractogenesis.A novel probabilistic analysis tool,the sparse Bayesian learning(SBL)algorithm,is described for reconstructing the most-probable size distribution ofα-crystallin and their aggregates in an ocular lens from the DLS data.The performance of the algorithm is evaluated by analyzing simulated correlation data from known distributions and DLS data from the ocular lenses of a fetal calf,a Rhesus monkey,and a man,so as to establish the required efficiency of the SBL algorithm for clinical studies.
文摘In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occurrences. The multifaceted nature of these influences makes the surveillance of mass movements a highly intricate task, requiring an understanding of numerous interdependent variables. Recent years have seen an emergence in scholarly research aimed at integrating geophysical and geotechnical methodologies. The conjoint examination of geophysical and geotechnical data offers an enhanced perspective into subsurface structures. Within this work, a methodology is proposed for the synchronous analysis of electrical resistivity geophysical data and geotechnical data, specifically those extracted from the Light Dynamic Penetrometer (DPL) and Standard Penetration Test (SPT). This study involved a linear fitting process to correlate resistivity with N10/SPT N-values from DPL/SPT soundings, culminating in a 2D profile of N10/SPT N-values predicated on electrical profiles. The findings of this research furnish invaluable insights into slope stability by allowing for a two-dimensional representation of penetration resistance properties. Through the synthesis of geophysical and geotechnical data, this project aims to augment the comprehension of subsurface conditions, with potential implications for refining landslide risk evaluations. This endeavor offers insight into the formulation of more effective and precise slope management protocols and disaster prevention strategies.
基金supported by the National Natural Science Foundation of China(Nos.62405176 and 62175009)the Natural Science Foundation of Shanghai(No.24ZR1435000)+3 种基金the Open Project Program of SJTU Pinghu Institute of Intelligent Optoelectronics(No.2022SP10E202)the Science and Technology on Sonar Laboratory(No.6142109KF212207)the Shanghai Jiao Tong University 2030 Initiative(No.WH510363001-13)the Research Fund of Shanghai Jiao Tong University Explore X。
文摘Light-beam shifts accompanied by propagation between two media show potential in applications such as optical sensing,optical communication,and optical computing.However,existing work tends to focus on the static response of the device,i.e.,the beam shift when the structural parameters and incident conditions are fixed.Here,we analyze the dynamics of beam shifting via photonic crystal slabs under refractive index variation.On the one hand,we investigate the trend of cross-polarized phase gradient under small changes in refractive index.Simulation results show that the direction of the beam shift can change by more than 50°for a refractive index change of only 0.06.On the other hand,we study the interaction of incident light with the far-field polarizations of bound states in the continuum in the presence of a refractive index jump in the phase-change material.In this case,simulation results show that the large change in the Pancharatnam-Berry phase gradient causes the beam to move widely,with a change in beam direction of 61.30°and a change in beam displacement of 15μm.Furthermore,all displacement amounts are comparable to the radius of the incident beam(~8μm).Our work provides a new perspective on the study of beam shifts,which can advance practical applications of beam shift in sensing,intelligent detecting,and beam control.
基金supported by the National Research Foundation of Korea(NRF)grants(RS-2025-00559639)the Samsung Science and Technology Foundation(SSTP-BA2102-05)the MSIT(Ministry of Science and ICT)under the ITRC(Information Technology Research Center)support program(IITP-2022-RS-2022-00164799).
文摘Ultrafast tip-based microscopy has evolved to meet three critical parameters in optical characterization:spatial,spectral,and temporal resolution.This advancement provides deep insights into light-matter interactions in both real time and real space.In particular,it allows direct observation of polaritons,quantum states,and nonequilibrium dynamics,especially in low-dimensional quantum materials.
文摘The nanometer cobalt blue pigments were prepared by microemulsion method. Using dynamic light scattering(DLS) test method, the influences of water content on the size of liquid drop of microemulsion and the liquid drop of microemulsion on the final diameter of nanometer particle were studied in the course of preparation. Accordingly, the method to control the diameter of nanometer particle by changing water content was established. The nanometer cobalt blue particles were confirmed by XRD and TEM. Color parameters of pigments were determined. The quantum size effect of the pigments was discussed.
文摘A modified seeded growth process of silica particles with a continuous addition of tetraethyl orthosilicate （TEOS） was presented to control the diameter of silica particles. The diameter of particles was monitored by dynamic light scattering to control the addition of TEOS. The increase in the diameter of the silica particles with time and the addition of TEOS was investigated. The diameter of silica seeds increased from 193 nm to 446 nm in 4 h. The final diameter of silica particles was tailored within the range of ±5 nm to the target diameter. Silica particles with diameter of 446 nm were synthesized and assembled into photonic crystals with a pseudo band gap centered at just 1000 nm. The feasibility and practicability of this modified seeded growth process was verified.
基金the National Natural Science Foundation of China(Nos.41501241 and 41530855)the Natural Science Foundation of Chongqing,China(No.cstc2015jcyj A00036)the Fundamental Research Funds for the Central Universities of China(No.XDJK2017D199)for supporting this research
文摘Specific ion effects(Hofmeister effects)have recently attracted the attention of soil scientists,and it has been found that ionic non-classic polarization plays an important role in the specific ion effect in soil.However,this explanation cannot be applied to H+.The aim of this work was to characterize the specific ion effect of H+on variably charged soil(yellow soil)colloid aggregation.The total average aggregation(TAA)rate,critical coagulation concentration(CCC),activation energy,and zeta potential were used to characterize and compare the specific ion effects of H+,K+,and Na+.Results showed that strong specific ion effects of H+,K+,and Na+existed in variably charged soil colloid aggregation.The TAA rate,CCC,and activation energy were sensitive to H+,and the addition of a small amount of H+changed the TAA rate,CCC,and activation energy markedly.The zeta potential results indicated that the specific ion effects of H+,K+,and Na+on soil colloid aggregation were caused by the specific ion effects of H+,K+,and Na+on the soil electric field strength.In addition,the origin of the specific ion effect for H+was its chemical adsorption onto surfaces,while those for alkali cations were non-classic polarization.This study indicated that H+,which occurs naturally in variably charged soils,will dominate variably charged soil colloid aggregation.
基金The work was supported by the Natural Science Foundation of China (No. 29903006 29973023).
文摘Spontaneous vesicles from the mixed aqueous solution of poly-tailed cationic surfactant PTA and anionic surfactant AOT are firstly obtained. Vesicle formation and characterizations are demonstrated by negative-staining TEM and dynamic light scattering. A monodisperse vesicle system is obtained with a polydispersity of 0.082. Ultrasonication can promote the vesicle formation. Mechanism of vesicle formation is discussed from the viewpoint of molecular interaction.
基金the sponsorship from the Brazilian government agencies CNPqFAPES
文摘Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase both in the use and application of the in situ tests: cone penetration test(CPT) and dynamic probing(DP). Several empirical SPT-CPT and dynamic probing light(DPL)-CPT correlations for sandy soils have been discussed in the literature. New SPT-CPT and DPL-CPT correlations for the sandy soils of the city of Vitoria, in the southeast of Brazil, are suggested in this paper. Statistical analyses to evaluate the quality of the data used are performed, and the suggested correlations are validated with several previous published datasets. The paper also provides some insights into SPT-CPT correlations and soil characteristics(i.e. the mean particle size and the fines fraction of the soil).
