In shale reservoirs,fluids are often confined within nanopores,leading to apparent effects on the properties and phase behavior of the fluid.However,previous studies have primarily focused on the effect of capillary p...In shale reservoirs,fluids are often confined within nanopores,leading to apparent effects on the properties and phase behavior of the fluid.However,previous studies have primarily focused on the effect of capillary pressure or adsorption on well performance,and only a very limited number of studies have researched the complex and coupled impact of confinement on capillarity,adsorption,and interactions between fluid molecules and pore walls.Therefore,in this study,an effective method is developed for evaluating the coupled effects of nanopore confinement on CO_(2) injection performance.First,a comprehensive thermodynamic model that incorporates adsorption,capillary pressure,and molecule-wall interaction in nanopores by modifying the Peng-Robinson equation of state(PR-EOS)is proposed.Subsequently,the calculated critical properties of different components are validated against experimental measured data,illustrating that the developed model can accurately predict the properties of the components of CO_(2)-hydrocarbon systems.Numerical simulations of field-scale case studies were then performed and calibrated using a modified phase equilibrium model.Typical fluid properties were inputted to investigate the effect of nanopore confinement on the CO_(2) injection performance.The results of this study show that the ultimate recovery factor increases by approximately 4.61%at a pore size of 10 nm,indicating that nanopore confinement is advantageous to well performance.Light hydrocarbons undergo more intense mass transfer than heavy hydrocarbons.Furthermore,as the pore radius decreased from 100 nm to 10 nm,the CO_(2) storage coefficient increased by 2.8%.The findings of this study deepen the collective understanding of the effect of nanopore confinement on CO_(2) displacement and storage,which has significant field-scale applications.展开更多
In this research,a series of biaxial compression and biaxial fatigue tests were conducted to investigate the mechanical behaviors of marble and sandstone under biaxial confinements.Experimental results demonstrate tha...In this research,a series of biaxial compression and biaxial fatigue tests were conducted to investigate the mechanical behaviors of marble and sandstone under biaxial confinements.Experimental results demonstrate that the biaxial compressive strength of rocks under biaxial compression increases firstly,and subsequently decreases with increase of the intermediate principal stress.The fatigue failure characteristics of the rocks in biaxial fatigue tests are functions of the peak value of fatigue loads,the intermediate principal stress and the rock lithology.With the increase of the peak values of fatigue loads,the fatigue lives of rocks decrease.The intermediate principal stress strengthens the resistance ability of rocks to fatigue loads except considering the strength increasing under biaxial confinements.The fatigue lives of rocks increase with the increase of the intermediate principal stress under the same ratio of the fatigue load and their biaxial compressive strength.The acoustic emission(AE)and fragments studies showed that the sandstone has higher ability to resist the fatigue loads compared to the marble,and the marble generated a greater number of smaller fragments after fatigue failure compared to the sandstone.So,it can be inferred that the rock breaking efficiency and rock burst is higher or severer induced by fatigue loading than that induced by monotonous quasi-static loading,especially for hard rocks.展开更多
The self-assembly of linear ABC triblock copolymers under cylindrical confinements is investigated in two- dimensional space using the real-space self-consistent field theory. The effects of confinement degrees and pr...The self-assembly of linear ABC triblock copolymers under cylindrical confinements is investigated in two- dimensional space using the real-space self-consistent field theory. The effects of confinement degrees and preferential strengths on the triblock copolymer phase behaviors with special polymer parameters are first considered. On one hand, different confinement degrees cause different phase behaviors in nanopores with the neutral surfaces. Moreover, the strongly preferential surface fields can surpass the confinement degrees and volume fractions in determing the confined phase behaviors. On the other hand, in contrast, confined morphologies are more sensitive to the variations in the A-preferential surface field strength. Subsequently, the incompatibility degrees between different blocks are systematically varied under cylindrical nanopore confinements. Under cylindrical nanopore confinements, the morphologies are very sensitive to the variations in the incompatibility degrees. Meanwhile, nanopore confinements can affect order-disorder and order-order transition points in the bulk. The corresponding free, internal, and entropic energies as well as the order parameters are also quantificationally examined to deeply investigate the confined phase mechanisms, and a number of morphological transitions are confirmed to be of first-order. These findings may guide the design of novel nanostructures based on triblock copolymers by introducing confinements.展开更多
Density modulation experiments are powerful experimental schemes for the study of particle transport. The diffusion coefficients （D） and convection velocity （V）, which cannot be evaluated from the particle balance...Density modulation experiments are powerful experimental schemes for the study of particle transport. The diffusion coefficients （D） and convection velocity （V）, which cannot be evaluated from the particle balance in the equilibrium state, can be obtained separately. Further, the estimated values of D and V are determined independent of the absolute value of the particle source rate, which is difficult to obtain experimentally. However, the sensitivities and interpretation of D and V from the modulation experiments need to be considered. This paper describes numerical techniques for solving the particle balance equation of the modulation components. Examples of the analysis are shown regarding the data of LHD experiments, and the results of the modulation experiments are discussed.展开更多
The development of lithium-sulfur batteries(LSBs)is restricted by their poor cycle stability and rate performance due to the low conductivity of sulfur and severe shuttle effect.Herein,an N,O co-doped graphene layered...The development of lithium-sulfur batteries(LSBs)is restricted by their poor cycle stability and rate performance due to the low conductivity of sulfur and severe shuttle effect.Herein,an N,O co-doped graphene layered block(NOGB)with many dents on the graphene sheets is designed as effective sulfur host for high-performance LSB s.The sulfur platelets are physically confined into the dents and closely contacted with the graphene scaffold,ensuring structural stability and high conductivity.The highly doped N and O atoms can prevent the shuttle effect of sulfur species by strong chemical adsorption.Moreover,the micropores on the graphene sheets enable fast Li^+transport through the blocks.As a result,the obtained NOGB/S composite with 76 wt%sulfur content shows a high capacity of 1413 mAh g^-1 at 0.1 C,good rate performance of 433 mAh g^-1 at 10 C,and remarkable stability with 526 mAh g^-1 at after 1000 cycles at 1 C(average decay rate:0.038%per cycle).Our design provides a comprehensive route for simultaneously improving the conductivity,ion transport kinetics,and preventing the shuttle effect in LSBs.展开更多
Ultrathin corrugated metallic structures have been proved to support spoof surface plasmon polariton (SPP) modes on two-dimension (2D) planar microwave circuits.However,to provide stronger field confinement,larger wid...Ultrathin corrugated metallic structures have been proved to support spoof surface plasmon polariton (SPP) modes on two-dimension (2D) planar microwave circuits.However,to provide stronger field confinement,larger width of strip is required to load deeper grooves,which is cumbersome in modern large-scale integrated circuits and chips.In this work,a new spoof SPP transmission line (TL) with zigzag grooves is proposed.This new structure can achieve stronger field confinement compared to conventional one with the same strip width.In other words,the proposed spoof SPP TL behaves equivalently to a conventional one with much larger size.Dispersion analysis theoretically indicates the negative correlation between the ability of field confinement and cutoff frequencies of spoof SPP TLs.Numerical simulations indicate that the cutoff frequency of the proposed TL is lower than the conventional one and can be easily modified with the fixed size.Furthermore,two samples of the new and conventional spoof SPP TLs are fabricated for experimental demonstration.Measured S-parameters and field distributions verify the ultra-strong ability of field confinement of the proposed spoof SPP TL.Hence,this novel spoof SPP structure with ultra-strong field confinement may find wide applications in microwave and terahertz engineering.展开更多
Implant materials,as foreign objects to host,can cause various degrees of inflammation in most cases.The inflammation is triggered by a series of immune responses and directly impacts the tissue regeneration process,w...Implant materials,as foreign objects to host,can cause various degrees of inflammation in most cases.The inflammation is triggered by a series of immune responses and directly impacts the tissue regeneration process,which determines the outcome of tissue repair.The immune responses are complex process involving numerous immune cells and can be divide into innate immune and adaptive immune responses.Once materials are implanted,innate immune responses are activated under the mediation of several immune cells(e.g.neutrophils and macrophages),meanwhile immature dendritic cells(imDCs)are recruited to the implant sites to recognize,internalize and process antigens.Upon antigen uptake,imDCs gradually differentiate into mature dendritic cells(mDCs)and migrate to secondary lymph nodes.In the lymph nodes,mDCs present processed antigen peptides to naive T lymphocytes and activate their antigen specific proliferation,resulting in initiation of adaptive immune responses.Due to their key position in the immune system,serving to bridge innate and adaptive immunity,DCs are crucial to guiding and modulating the immune responses caused by implanted materials.Therefore,figuring out the response of DCs to implanted materials and the exact role of DCs in tissue healing processes will provide deeper insight for the rational design of biomaterials.Previous studies on the effects of implants on immune functions of DCs are mainly focused on physical and chemical properties of the materials(e.g.released chemical composition,surface chemistry,substrate stiffness and surface topography).All these factors will change the microenvironment of the tissue around implant materials,which affect the immune functions of DCs.However,the change of microenvironment not only directly derives from the physical and chemical properties of the material(intrinsic),but also indirectly results from the remodeled extracellular matrix(ECM)caused by implanted materials.When blood or tissue fluid contact with materials after implantation,proteins(e.g.fibrin and collagen)will absorb and deposit on the surface of implants,leading to a provisionally stable matrix with microporous fibrous-liked network structure.It means that the remodeled ECM can provide adhesion sites for recruited DCs and form spatial confinement.DCs,as a kind of cells that are extremely sensitive to mechanical stimuli,theoretically,can response to the mechanical stimuli coming from spatial confinement of remodeled ECM,which may lead to a series of modulations in their cell morphologies and immune functions.Then,the remodeled ECM is a non-negligible mechanical cue.However,to the best of our knowledge,there is a lack of a simple and effective model to establish the relationship between the immune functions of DCs and remodeled ECM.Most studies on the responses of DCs to implanted materials are still based on suspension culture model,which is the normal status of DCs in vitro culture systems.In addition,the processes by which DC exerts immune functions(both endocytosis and antigen presentation)are dynamically physical interaction.It means that the changes of DCs’immune functions are highly correlated with the changes of their biomechanical characteristics caused by remodeled ECM.In this work,we have found that the ECM was remodeled by a large amount of fibrin matrix deposited on the surface of implants in the early stage of the inflammations following implantation.Thus,we used non-toxic salmon fibrin hydrogels with microporous fibrous-liked network structure to mimic the deposited fibrin matrix.Then,human monocyte-derived DCs were cultured on the surface and inside of the fibrin hydrogels to mimic the different spatial confinement states of fibrin matrix.Our results indicated that cell morphologies and cytoskeleton structures of DCs were regulated by the spatial confinement of fibrin hydrogels,resulting in generating mechanical stimuli for DCs.Furthermore,we have found that the biomechanical characteristics and the immune functions of both imDCs and mDC were also modulated.Considering the changes in surface markers,secreted cytokines and biomechanical characteristics of DCs,it indicates that the tendency and magnitude of modulations were highly associated with the spatial confinement of fibrin hydrogels.This model demonstrated that mechanical stimuli deriving from spatial confinement of deposited fibrin matrix is an important factor for regulating the biomechanical characteristics and immune functions of DCs.展开更多
In a charged colloidal system, the influence on depletion interaction between two like-charged macro-ions is studied through Monte Carlo simulation in this paper. The numerical results show that this depletion force i...In a charged colloidal system, the influence on depletion interaction between two like-charged macro-ions is studied through Monte Carlo simulation in this paper. The numerical results show that this depletion force is affected by both the electrostatic interactions between charged spheres and charged plates and by the geometrical factor of the two charged plates, and they further indicate that the influence of geometrical confinement on the depletion interaction is larger than that of electrostatic potential.展开更多
In this work,a surface-potential based compact model focusing on the quantum confinement effects of ultimately scaled gate-all-around(GAA)MOSFET is presented.Energy quantization with sub-band formation along the radiu...In this work,a surface-potential based compact model focusing on the quantum confinement effects of ultimately scaled gate-all-around(GAA)MOSFET is presented.Energy quantization with sub-band formation along the radius direction of cylindrical GAAs or thickness direction of nanosheet GAAs leads to significant quantization effects.An analytical model of surface potentials is developed by solving the Poisson equation with incorporating sub-band effects.In combination with the existing transport model framework,charge-voltage and current-voltage formulations are developed based on the surface potential.The model formulations are then extensively validated using TCAD numerical simulations as well as Si data of nanosheet GAA MOSFETs.Simulations of typical circuits verify the model robustness and convergence for its applications in GAA technology.展开更多
The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investiga...The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investigates how quantum confinement governs the charge transport,exciton dynamics,and emission efficiency in QD-LEDs,using CsPbI_(3) QDs as a model system.By systematically varying QD sizes,we reveal size-dependent trade-offs in LED performance,such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities.Our findings offer critical insights into the design of high-performance QD-LEDs,paving the way for scalable and energy-efficient optoelectronic devices.展开更多
In sub nanometer carbon nanotubes,water exhibits unique dynamic characteristics,and in the high-frequency region of the infrared spectrum,where the stretching vibrations of the internal oxygen-hydrogen(O-H)bonds are c...In sub nanometer carbon nanotubes,water exhibits unique dynamic characteristics,and in the high-frequency region of the infrared spectrum,where the stretching vibrations of the internal oxygen-hydrogen(O-H)bonds are closely related to the hydrogen bonds(H-bonds)network between water molecules.Therefore,it is crucial to analyze the relationship between these two aspects.In this paper,the infrared spectrum and motion characteristics of the stretching vibrations of the O-H bonds in one-dimensional confined water(1DCW)and bulk water(BW)in(6,6)single-walled carbon nanotubes(SWNT)are studied by molecular dynamics simulations.The results show that the stretching vibrations of the two O-H bonds in 1DCW exhibit different frequencies in the infrared spectrum,while the O-H bonds in BW display two identical main frequency peaks.Further analysis using the spring oscillator model reveals that the difference in the stretching amplitude of the O-H bonds is the main factor causing the change in vibration frequency,where an increase in stretching amplitude leads to a decrease in spring stiffness and,consequently,a lower vibration frequency.A more in-depth study found that the interaction of H-bonds between water molecules is the fundamental cause of the increased stretching amplitude and decreased vibration frequency of the O-H bonds.Finally,by analyzing the motion trajectory of the H atoms,the dynamic differences between 1DCW and BW are clearly revealed.These findings provide a new perspective for understanding the behavior of water molecules at the nanoscale and are of significant importance in advancing the development of infrared spectroscopy detection technology.展开更多
We investigate the spatial and temporal correlations of hot-electron generation in high-intensity laser interaction with massive and thin copper targets under conditions relevant to inertial confinement fusion.Using K...We investigate the spatial and temporal correlations of hot-electron generation in high-intensity laser interaction with massive and thin copper targets under conditions relevant to inertial confinement fusion.Using Ka time-resolved imaging,it is found that in the case of massive targets,the hot-electron generation follows the laser pulse intensity with a short delay needed for favorable plasma formation.Conversely,a significant delay in the x-ray emission compared with the laser pulse intensity profile is observed in the case of thin targets.Theoretical analysis and numerical simulations suggest that this is related to radiation preheating of the foil and the increase in hot-electron lifetime in a hot expanding plasma.展开更多
Groundwater quality is pivotal for sustainable resource management,necessitating comprehen-sive investigation to safeguard this critical resource.This study introduces a novel methodology that inte-grates stiff diagra...Groundwater quality is pivotal for sustainable resource management,necessitating comprehen-sive investigation to safeguard this critical resource.This study introduces a novel methodology that inte-grates stiff diagrams,geostatistical analysis,and geometric computation to delineate the extent of a confined aquifer within the Chahrdoly aquifer,located west of Hamadan,Iran.For the first time,this approach combines these tools to map the boundaries of a confined aquifer based on hydrochemical characteristics.Stiff diagrams were used to calculate geometric parameters from groundwater chemistry data,followed by simulation using a linear model incorporating the semivariogram parameterγ(h).The Root Mean Square Error(RMSE)of the linear model was used to differentiate confined from unconfined aquifers based on hydrochemical signatures.Validation was conducted by generating a cross-sectional hydrogeological layer from well logs,confirming the presence of aquitard layers.The results successufully delineated the confined aquifer's extent,showing strong agreement with hydrogeological log data.By integrating stiff diagrams with semivariogram analysis,this study enhances the understanding of hydrochemical processes,offering a robust framework for groundwater resource identification and management.展开更多
Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,ins...Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,insufficient doping of the ablator material can result in highenergy X-ray preheat,which may trigger the development of a classical-like Rayleigh-Taylor instability(RTI)at the fuel-ablator interface.In implosion experiments at the Shenguang 100 kJ-level laser facility,the primary source of perturbation is the roughness of the inner DT ice interface.In this study,we propose an analytical model to describe the feed-out process of the initial roughness of the inner DT ice interface.The perturbation amplitude derived from this model serves as the initial seed for the late-time RTI during the acceleration phase.Our findings confirm the presence of classical-like RTI at the fuel-ablator interface.Numerical simulations conducted using a radiation hydrodynamic code validate the proposed analytical model and demonstrate the existence of a peak mode number in both the feed-out process and the classical-like RTI.It provides an alternative bridge between the current target fabrication limitations and the unexpected implosion performance.展开更多
The conformational and dynamical properties of a long semi-flexible active polymer chain confined in a circular cavity are studied by using Langevin dynamics simulation method.Results show that the steady radius of gy...The conformational and dynamical properties of a long semi-flexible active polymer chain confined in a circular cavity are studied by using Langevin dynamics simulation method.Results show that the steady radius of gyration of the polymer decreases monotonically with increasing the active force.Interestingly,the polymer forms stable compact spiral with directional rotation at the steady state when the active force is large.Both the radius of gyration and the angular velocity of the spiral are nearly independent of the cavity size,but show scaling relations with the active force and the polymer length.It is further found that the formation of the stable compact spiral in most cases is a two-step relaxation process,where the polymer first forms a metastable swelling quasi spiral and then transforms into the stable compacted spiral near the wall of the cavity.The relaxation time is mainly determined by the transformation of the swelling quasi spiral,and shows remarkable dependence on the size of the cavity.Specially,when the circumference of the circular is nearly equivalent to the polymer length,it is difficult for the polymer to form the compacted spiral,leading to a large relaxation time.The underlying mechanism of the formation of the compacted spiral is revealed.展开更多
Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdis ciplinar...Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdis ciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.PST is sponsored jointly by the Institute of Plasma Physics of the Chinese Academy of Sciences,and the Chinese Society of Theoretical and Applied Mechanics.The journal joined the Scienc e Citation Index in 2003,the Engineering Index in 2006,and became published online by IOP Publishing Ltd.in 2006.展开更多
The structure of water and proton transfer under nanoscale confinement has garnered significant attention due to its crucial role in elucidating various phenomena across multiple scientific disciplines.However,there r...The structure of water and proton transfer under nanoscale confinement has garnered significant attention due to its crucial role in elucidating various phenomena across multiple scientific disciplines.However,there remains a lack of consensus on fundamental properties such as diffusion behavior and the nature of hydrogen bonding in confined environments.In this work,we investigated the influence of confinement on proton transfer in water confined within graphene sheets at various spacings by ab initio molecule dynamic and multiscale analysis with time evolution of structural properties,graph theory and persistent homology.We found that reducing the graphene interlayer distance while maintaining water density close to that of bulk water leads to a decrease in proton transfer frequency.In contrast,reducing the interlayer distance without maintaining bulk-like water density results in an increase in proton transfer frequency.This difference is mainly due to the confinement conditions:when density is unchanged,the hydrogen bond network remains similar with significant layering,while compressive stress that increases density leads to a more planar hydrogen bond network,promoting faster proton transfer.Our findings elucidate the complex relationship between confinement and proton transfer dynamics,with implications for understanding proton transport in confined environments,relevant to energy storage and material design.展开更多
Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power densi...Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power density with improved trade-off between membrane permeability and selectivity.Herein,polyelectrolyte hydrogels(channel width,2.2 nm)with inherent high ion conductivity have been demonstrated to enable excellent selective ion transfer when confined in cylindrical anodized aluminum pore with lateral size even up to the submillimeter scale(radius,0.1 mm).The membrane permeability of the anti-swelling hydrogel can also be further increased with cellulose nanofibers.With real seawater and river water,the output power density of a three-chamber cell on behalf of repeat unit of RED system can reach up to 8.99 W m^(-2)(per unit total membrane area),much better than state-of-the-art membranes.This work provides a new strategy for the preparation of polyelectrolyte hydrogel-based ion-selective membranes,owning broad application prospects in the fields of osmotic energy collection,electrodialysis,flow battery and so on.展开更多
Single-molecule junctions are building blocks for constructing molecular devices.However,intermolecular interactions like winding bring additional interference among the surrounding molecules,which inhibits the intrin...Single-molecule junctions are building blocks for constructing molecular devices.However,intermolecular interactions like winding bring additional interference among the surrounding molecules,which inhibits the intrinsic coherent transport through single-molecule junctions.Here,we employed a nanocavity(dimethoxypillar[5]arene,DMP[5]),which is analogous to electric cables,to confine the conformation of flexible chains(1,8-diaminooctane,DAO)via host-vip interaction.Single-molecule conductance measurements indicate that the conductance of DAO encapsulated with DMP[5]is as high as that of pure DAO,as reproduced by theoretical simulations.Intriguingly,the molecular lengths of the DAO encapsulated with DMP[5]increase from 1.13 nm to 1.46 nm compared with the pure DAO,indicating that DMP[5]keeps DAO upright-standing via the confinement effect.This work provides a new strategy to decouple the intermolecular interaction by employing an insulating sheath,enabling the high-density integration of single-molecule devices.展开更多
Active matter exhibits collective motions at various scales.Geometric confinement has been identified as an effective way to control and manipulate active fluids,with much attention given to external factors.However,t...Active matter exhibits collective motions at various scales.Geometric confinement has been identified as an effective way to control and manipulate active fluids,with much attention given to external factors.However,the impact of the inherent properties of active particles on collective motion under confined conditions remains elusive.Here,we use a highly tunable active nematics model to study active systems under confinement,focusing on the effect of the self-driven speed of active particles.We identify three distinct states characterized by unique particle and flow fields within confined active nematic systems,among which circular rotation emerges as a collective motion involving rotational movement in both particle and flow fields.The theoretical phase diagram shows that increasing the self-driven speed of active particles significantly enhances the region of the circular rotation state and improves its stability.Our results provide insights into the formation of high quality vortices in confined active nematic systems.展开更多
基金supported by National Natural Science Foundation of China(Nos.52474052 and 52074248)Young Elite Scientists Sponsorship Program by Beijing Association for Science and Technology,China(No.BYESS2023414)Scientific Research Innovation Capability Support Project for Young Faculty,China(No.ZYGXQNJSKYCXNLZCXM-E14).
文摘In shale reservoirs,fluids are often confined within nanopores,leading to apparent effects on the properties and phase behavior of the fluid.However,previous studies have primarily focused on the effect of capillary pressure or adsorption on well performance,and only a very limited number of studies have researched the complex and coupled impact of confinement on capillarity,adsorption,and interactions between fluid molecules and pore walls.Therefore,in this study,an effective method is developed for evaluating the coupled effects of nanopore confinement on CO_(2) injection performance.First,a comprehensive thermodynamic model that incorporates adsorption,capillary pressure,and molecule-wall interaction in nanopores by modifying the Peng-Robinson equation of state(PR-EOS)is proposed.Subsequently,the calculated critical properties of different components are validated against experimental measured data,illustrating that the developed model can accurately predict the properties of the components of CO_(2)-hydrocarbon systems.Numerical simulations of field-scale case studies were then performed and calibrated using a modified phase equilibrium model.Typical fluid properties were inputted to investigate the effect of nanopore confinement on the CO_(2) injection performance.The results of this study show that the ultimate recovery factor increases by approximately 4.61%at a pore size of 10 nm,indicating that nanopore confinement is advantageous to well performance.Light hydrocarbons undergo more intense mass transfer than heavy hydrocarbons.Furthermore,as the pore radius decreased from 100 nm to 10 nm,the CO_(2) storage coefficient increased by 2.8%.The findings of this study deepen the collective understanding of the effect of nanopore confinement on CO_(2) displacement and storage,which has significant field-scale applications.
基金Projects(51774326,41807259)supported by the National Natural Science Foundation of ChinaProject(MDPC201917)supported by Mining Disaster Prevention and Control Ministry Key Laboratory at Shandong University of Science and Technology,China。
文摘In this research,a series of biaxial compression and biaxial fatigue tests were conducted to investigate the mechanical behaviors of marble and sandstone under biaxial confinements.Experimental results demonstrate that the biaxial compressive strength of rocks under biaxial compression increases firstly,and subsequently decreases with increase of the intermediate principal stress.The fatigue failure characteristics of the rocks in biaxial fatigue tests are functions of the peak value of fatigue loads,the intermediate principal stress and the rock lithology.With the increase of the peak values of fatigue loads,the fatigue lives of rocks decrease.The intermediate principal stress strengthens the resistance ability of rocks to fatigue loads except considering the strength increasing under biaxial confinements.The fatigue lives of rocks increase with the increase of the intermediate principal stress under the same ratio of the fatigue load and their biaxial compressive strength.The acoustic emission(AE)and fragments studies showed that the sandstone has higher ability to resist the fatigue loads compared to the marble,and the marble generated a greater number of smaller fragments after fatigue failure compared to the sandstone.So,it can be inferred that the rock breaking efficiency and rock burst is higher or severer induced by fatigue loading than that induced by monotonous quasi-static loading,especially for hard rocks.
基金supported by the General Program of National Natural Science Foundation of China(Nos. 21174131, 20974081, 21074096, and 21104060)the Natural Science Foundation of Zhejiang Province(Nos. Y4090174 and Y6100033)
文摘The self-assembly of linear ABC triblock copolymers under cylindrical confinements is investigated in two- dimensional space using the real-space self-consistent field theory. The effects of confinement degrees and preferential strengths on the triblock copolymer phase behaviors with special polymer parameters are first considered. On one hand, different confinement degrees cause different phase behaviors in nanopores with the neutral surfaces. Moreover, the strongly preferential surface fields can surpass the confinement degrees and volume fractions in determing the confined phase behaviors. On the other hand, in contrast, confined morphologies are more sensitive to the variations in the A-preferential surface field strength. Subsequently, the incompatibility degrees between different blocks are systematically varied under cylindrical nanopore confinements. Under cylindrical nanopore confinements, the morphologies are very sensitive to the variations in the incompatibility degrees. Meanwhile, nanopore confinements can affect order-disorder and order-order transition points in the bulk. The corresponding free, internal, and entropic energies as well as the order parameters are also quantificationally examined to deeply investigate the confined phase mechanisms, and a number of morphological transitions are confirmed to be of first-order. These findings may guide the design of novel nanostructures based on triblock copolymers by introducing confinements.
基金supported in part by the JSPS-CAS Core-University Program in the field of Plasma and Nuclear Fusion
文摘Density modulation experiments are powerful experimental schemes for the study of particle transport. The diffusion coefficients （D） and convection velocity （V）, which cannot be evaluated from the particle balance in the equilibrium state, can be obtained separately. Further, the estimated values of D and V are determined independent of the absolute value of the particle source rate, which is difficult to obtain experimentally. However, the sensitivities and interpretation of D and V from the modulation experiments need to be considered. This paper describes numerical techniques for solving the particle balance equation of the modulation components. Examples of the analysis are shown regarding the data of LHD experiments, and the results of the modulation experiments are discussed.
基金supported by the National Natural Science Foundation of China(Nos.51672055,51972342,51872656,and 51702275)the Taishan Scholar Project of Shandong Province(ts20190922)+3 种基金the Key Basic Research Project of Natural Science Foundation of Shandong Province(ZR2019ZD51)the Xinjiang Tianshan Xuesong Project(2018XS28)the Scientific Research Program of the Higher Education Institution of Xinjiang(XJEDU2017S003)the Xinjiang Tianchi Doctoral Project。
文摘The development of lithium-sulfur batteries(LSBs)is restricted by their poor cycle stability and rate performance due to the low conductivity of sulfur and severe shuttle effect.Herein,an N,O co-doped graphene layered block(NOGB)with many dents on the graphene sheets is designed as effective sulfur host for high-performance LSB s.The sulfur platelets are physically confined into the dents and closely contacted with the graphene scaffold,ensuring structural stability and high conductivity.The highly doped N and O atoms can prevent the shuttle effect of sulfur species by strong chemical adsorption.Moreover,the micropores on the graphene sheets enable fast Li^+transport through the blocks.As a result,the obtained NOGB/S composite with 76 wt%sulfur content shows a high capacity of 1413 mAh g^-1 at 0.1 C,good rate performance of 433 mAh g^-1 at 10 C,and remarkable stability with 526 mAh g^-1 at after 1000 cycles at 1 C(average decay rate:0.038%per cycle).Our design provides a comprehensive route for simultaneously improving the conductivity,ion transport kinetics,and preventing the shuttle effect in LSBs.
基金the National Natural Science Foundation of China under Grant Nos.61871127,61701246,61631007,61571117,61501112,61501117,61522106,61722106,61701107,and 61701108,and 111 Project under Grant No.111-2-05.
文摘Ultrathin corrugated metallic structures have been proved to support spoof surface plasmon polariton (SPP) modes on two-dimension (2D) planar microwave circuits.However,to provide stronger field confinement,larger width of strip is required to load deeper grooves,which is cumbersome in modern large-scale integrated circuits and chips.In this work,a new spoof SPP transmission line (TL) with zigzag grooves is proposed.This new structure can achieve stronger field confinement compared to conventional one with the same strip width.In other words,the proposed spoof SPP TL behaves equivalently to a conventional one with much larger size.Dispersion analysis theoretically indicates the negative correlation between the ability of field confinement and cutoff frequencies of spoof SPP TLs.Numerical simulations indicate that the cutoff frequency of the proposed TL is lower than the conventional one and can be easily modified with the fixed size.Furthermore,two samples of the new and conventional spoof SPP TLs are fabricated for experimental demonstration.Measured S-parameters and field distributions verify the ultra-strong ability of field confinement of the proposed spoof SPP TL.Hence,this novel spoof SPP structure with ultra-strong field confinement may find wide applications in microwave and terahertz engineering.
基金funded by grants from the National Natural Science Foundation of China ( 31771014, 11762006,31660258,31860262,11762006,81460254 )the 2011 Collaborative Innovation Program of Guizhou Province ( 2015-04)+1 种基金the Science and Technology Innovative Talent Team of Guizhou Province ( 2015-4021)the Science and Technology Foundation of Guizhou Province ( 2018-1412,2016-5676,2017-5718)
文摘Implant materials,as foreign objects to host,can cause various degrees of inflammation in most cases.The inflammation is triggered by a series of immune responses and directly impacts the tissue regeneration process,which determines the outcome of tissue repair.The immune responses are complex process involving numerous immune cells and can be divide into innate immune and adaptive immune responses.Once materials are implanted,innate immune responses are activated under the mediation of several immune cells(e.g.neutrophils and macrophages),meanwhile immature dendritic cells(imDCs)are recruited to the implant sites to recognize,internalize and process antigens.Upon antigen uptake,imDCs gradually differentiate into mature dendritic cells(mDCs)and migrate to secondary lymph nodes.In the lymph nodes,mDCs present processed antigen peptides to naive T lymphocytes and activate their antigen specific proliferation,resulting in initiation of adaptive immune responses.Due to their key position in the immune system,serving to bridge innate and adaptive immunity,DCs are crucial to guiding and modulating the immune responses caused by implanted materials.Therefore,figuring out the response of DCs to implanted materials and the exact role of DCs in tissue healing processes will provide deeper insight for the rational design of biomaterials.Previous studies on the effects of implants on immune functions of DCs are mainly focused on physical and chemical properties of the materials(e.g.released chemical composition,surface chemistry,substrate stiffness and surface topography).All these factors will change the microenvironment of the tissue around implant materials,which affect the immune functions of DCs.However,the change of microenvironment not only directly derives from the physical and chemical properties of the material(intrinsic),but also indirectly results from the remodeled extracellular matrix(ECM)caused by implanted materials.When blood or tissue fluid contact with materials after implantation,proteins(e.g.fibrin and collagen)will absorb and deposit on the surface of implants,leading to a provisionally stable matrix with microporous fibrous-liked network structure.It means that the remodeled ECM can provide adhesion sites for recruited DCs and form spatial confinement.DCs,as a kind of cells that are extremely sensitive to mechanical stimuli,theoretically,can response to the mechanical stimuli coming from spatial confinement of remodeled ECM,which may lead to a series of modulations in their cell morphologies and immune functions.Then,the remodeled ECM is a non-negligible mechanical cue.However,to the best of our knowledge,there is a lack of a simple and effective model to establish the relationship between the immune functions of DCs and remodeled ECM.Most studies on the responses of DCs to implanted materials are still based on suspension culture model,which is the normal status of DCs in vitro culture systems.In addition,the processes by which DC exerts immune functions(both endocytosis and antigen presentation)are dynamically physical interaction.It means that the changes of DCs’immune functions are highly correlated with the changes of their biomechanical characteristics caused by remodeled ECM.In this work,we have found that the ECM was remodeled by a large amount of fibrin matrix deposited on the surface of implants in the early stage of the inflammations following implantation.Thus,we used non-toxic salmon fibrin hydrogels with microporous fibrous-liked network structure to mimic the deposited fibrin matrix.Then,human monocyte-derived DCs were cultured on the surface and inside of the fibrin hydrogels to mimic the different spatial confinement states of fibrin matrix.Our results indicated that cell morphologies and cytoskeleton structures of DCs were regulated by the spatial confinement of fibrin hydrogels,resulting in generating mechanical stimuli for DCs.Furthermore,we have found that the biomechanical characteristics and the immune functions of both imDCs and mDC were also modulated.Considering the changes in surface markers,secreted cytokines and biomechanical characteristics of DCs,it indicates that the tendency and magnitude of modulations were highly associated with the spatial confinement of fibrin hydrogels.This model demonstrated that mechanical stimuli deriving from spatial confinement of deposited fibrin matrix is an important factor for regulating the biomechanical characteristics and immune functions of DCs.
基金supported by the National Natural Science Foundation of China (Grant Nos 10375042 and 10775018)the Scientific Research Fund of Hunan Provincial Education Department and Hunan Provincial Natural Science Foundation of China (GrantNo 08jj6043)the Construct Program of the Key discipline in Hunan Province,China
文摘In a charged colloidal system, the influence on depletion interaction between two like-charged macro-ions is studied through Monte Carlo simulation in this paper. The numerical results show that this depletion force is affected by both the electrostatic interactions between charged spheres and charged plates and by the geometrical factor of the two charged plates, and they further indicate that the influence of geometrical confinement on the depletion interaction is larger than that of electrostatic potential.
基金supported in part by the Natural Science Foundation of China(62125401 and 62074006)the major scientific instruments and equipments development grant(61927901)the Shenzhen Fundamental Research Program(GXWD20200827114656001).
文摘In this work,a surface-potential based compact model focusing on the quantum confinement effects of ultimately scaled gate-all-around(GAA)MOSFET is presented.Energy quantization with sub-band formation along the radius direction of cylindrical GAAs or thickness direction of nanosheet GAAs leads to significant quantization effects.An analytical model of surface potentials is developed by solving the Poisson equation with incorporating sub-band effects.In combination with the existing transport model framework,charge-voltage and current-voltage formulations are developed based on the surface potential.The model formulations are then extensively validated using TCAD numerical simulations as well as Si data of nanosheet GAA MOSFETs.Simulations of typical circuits verify the model robustness and convergence for its applications in GAA technology.
基金support from the National Key Research and Development Program of China(2024YFA1207700)National Natural Science Foundation of China(52072141,52102170).
文摘The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investigates how quantum confinement governs the charge transport,exciton dynamics,and emission efficiency in QD-LEDs,using CsPbI_(3) QDs as a model system.By systematically varying QD sizes,we reveal size-dependent trade-offs in LED performance,such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities.Our findings offer critical insights into the design of high-performance QD-LEDs,paving the way for scalable and energy-efficient optoelectronic devices.
基金Supported by the Natural Science Foundation of China(51705326,52075339)。
文摘In sub nanometer carbon nanotubes,water exhibits unique dynamic characteristics,and in the high-frequency region of the infrared spectrum,where the stretching vibrations of the internal oxygen-hydrogen(O-H)bonds are closely related to the hydrogen bonds(H-bonds)network between water molecules.Therefore,it is crucial to analyze the relationship between these two aspects.In this paper,the infrared spectrum and motion characteristics of the stretching vibrations of the O-H bonds in one-dimensional confined water(1DCW)and bulk water(BW)in(6,6)single-walled carbon nanotubes(SWNT)are studied by molecular dynamics simulations.The results show that the stretching vibrations of the two O-H bonds in 1DCW exhibit different frequencies in the infrared spectrum,while the O-H bonds in BW display two identical main frequency peaks.Further analysis using the spring oscillator model reveals that the difference in the stretching amplitude of the O-H bonds is the main factor causing the change in vibration frequency,where an increase in stretching amplitude leads to a decrease in spring stiffness and,consequently,a lower vibration frequency.A more in-depth study found that the interaction of H-bonds between water molecules is the fundamental cause of the increased stretching amplitude and decreased vibration frequency of the O-H bonds.Finally,by analyzing the motion trajectory of the H atoms,the dynamic differences between 1DCW and BW are clearly revealed.These findings provide a new perspective for understanding the behavior of water molecules at the nanoscale and are of significant importance in advancing the development of infrared spectroscopy detection technology.
基金funding via EUROfusion Enabling research Project No.AWP21-ENR-01-CEA-02“Advancing Shock Ignition for Direct-Drive Inertial Fusion,”the framework of the EUROfusion Consortium,funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No.101052200-EUROfusion)+2 种基金the Czech Ministry of Education,Youth and Sports (CMEYS) for funding the operation of the PALS facility (Grant No.LM2023068)the EuroHPC Joint Undertaking for awarding access to Karolina at IT4Innovations (VSB-TU),Czechia under Project No.EHPC-REG-2023R02-006(DD-23-157)the Ministry of Education,Youth and Sports of the Czech Republic through e-INFRA CZ (Grant No.ID:90140)
文摘We investigate the spatial and temporal correlations of hot-electron generation in high-intensity laser interaction with massive and thin copper targets under conditions relevant to inertial confinement fusion.Using Ka time-resolved imaging,it is found that in the case of massive targets,the hot-electron generation follows the laser pulse intensity with a short delay needed for favorable plasma formation.Conversely,a significant delay in the x-ray emission compared with the laser pulse intensity profile is observed in the case of thin targets.Theoretical analysis and numerical simulations suggest that this is related to radiation preheating of the foil and the increase in hot-electron lifetime in a hot expanding plasma.
文摘Groundwater quality is pivotal for sustainable resource management,necessitating comprehen-sive investigation to safeguard this critical resource.This study introduces a novel methodology that inte-grates stiff diagrams,geostatistical analysis,and geometric computation to delineate the extent of a confined aquifer within the Chahrdoly aquifer,located west of Hamadan,Iran.For the first time,this approach combines these tools to map the boundaries of a confined aquifer based on hydrochemical characteristics.Stiff diagrams were used to calculate geometric parameters from groundwater chemistry data,followed by simulation using a linear model incorporating the semivariogram parameterγ(h).The Root Mean Square Error(RMSE)of the linear model was used to differentiate confined from unconfined aquifers based on hydrochemical signatures.Validation was conducted by generating a cross-sectional hydrogeological layer from well logs,confirming the presence of aquitard layers.The results successufully delineated the confined aquifer's extent,showing strong agreement with hydrogeological log data.By integrating stiff diagrams with semivariogram analysis,this study enhances the understanding of hydrochemical processes,offering a robust framework for groundwater resource identification and management.
基金funded by the National Key R&D Program of China(Grant No.2023YFA1608400)the National Natural Science Foundation of China(Grant No.12302281).
文摘Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,insufficient doping of the ablator material can result in highenergy X-ray preheat,which may trigger the development of a classical-like Rayleigh-Taylor instability(RTI)at the fuel-ablator interface.In implosion experiments at the Shenguang 100 kJ-level laser facility,the primary source of perturbation is the roughness of the inner DT ice interface.In this study,we propose an analytical model to describe the feed-out process of the initial roughness of the inner DT ice interface.The perturbation amplitude derived from this model serves as the initial seed for the late-time RTI during the acceleration phase.Our findings confirm the presence of classical-like RTI at the fuel-ablator interface.Numerical simulations conducted using a radiation hydrodynamic code validate the proposed analytical model and demonstrate the existence of a peak mode number in both the feed-out process and the classical-like RTI.It provides an alternative bridge between the current target fabrication limitations and the unexpected implosion performance.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LY20A040004)the National Natural Science Foundation of China(Nos.22203060 and 11974305).
文摘The conformational and dynamical properties of a long semi-flexible active polymer chain confined in a circular cavity are studied by using Langevin dynamics simulation method.Results show that the steady radius of gyration of the polymer decreases monotonically with increasing the active force.Interestingly,the polymer forms stable compact spiral with directional rotation at the steady state when the active force is large.Both the radius of gyration and the angular velocity of the spiral are nearly independent of the cavity size,but show scaling relations with the active force and the polymer length.It is further found that the formation of the stable compact spiral in most cases is a two-step relaxation process,where the polymer first forms a metastable swelling quasi spiral and then transforms into the stable compacted spiral near the wall of the cavity.The relaxation time is mainly determined by the transformation of the swelling quasi spiral,and shows remarkable dependence on the size of the cavity.Specially,when the circumference of the circular is nearly equivalent to the polymer length,it is difficult for the polymer to form the compacted spiral,leading to a large relaxation time.The underlying mechanism of the formation of the compacted spiral is revealed.
文摘Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdis ciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.PST is sponsored jointly by the Institute of Plasma Physics of the Chinese Academy of Sciences,and the Chinese Society of Theoretical and Applied Mechanics.The journal joined the Scienc e Citation Index in 2003,the Engineering Index in 2006,and became published online by IOP Publishing Ltd.in 2006.
基金supported by the Natural Science Foundation of Xiamen,China(3502Z202472001)the National Natural Science Foundation of China(22402163,22021001,21925404,T2293692,and 22361132532).
文摘The structure of water and proton transfer under nanoscale confinement has garnered significant attention due to its crucial role in elucidating various phenomena across multiple scientific disciplines.However,there remains a lack of consensus on fundamental properties such as diffusion behavior and the nature of hydrogen bonding in confined environments.In this work,we investigated the influence of confinement on proton transfer in water confined within graphene sheets at various spacings by ab initio molecule dynamic and multiscale analysis with time evolution of structural properties,graph theory and persistent homology.We found that reducing the graphene interlayer distance while maintaining water density close to that of bulk water leads to a decrease in proton transfer frequency.In contrast,reducing the interlayer distance without maintaining bulk-like water density results in an increase in proton transfer frequency.This difference is mainly due to the confinement conditions:when density is unchanged,the hydrogen bond network remains similar with significant layering,while compressive stress that increases density leads to a more planar hydrogen bond network,promoting faster proton transfer.Our findings elucidate the complex relationship between confinement and proton transfer dynamics,with implications for understanding proton transport in confined environments,relevant to energy storage and material design.
基金supported by The Project of“20 Items of University”of Jinan(Grant No.202228078)Innovative Research Team in Higher Educational Institutions of Shandong Province(Grant No.2023KJ107)+2 种基金Taishan Scholars Program of Shandong Province(tsqn201812085)National Natural Science Foundation of China(Grant No.51903102,Grant No.52376063,Grant No.52302256)China Postdoctoral Science Foundation(Grant No.2023MD744223).
文摘Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power density with improved trade-off between membrane permeability and selectivity.Herein,polyelectrolyte hydrogels(channel width,2.2 nm)with inherent high ion conductivity have been demonstrated to enable excellent selective ion transfer when confined in cylindrical anodized aluminum pore with lateral size even up to the submillimeter scale(radius,0.1 mm).The membrane permeability of the anti-swelling hydrogel can also be further increased with cellulose nanofibers.With real seawater and river water,the output power density of a three-chamber cell on behalf of repeat unit of RED system can reach up to 8.99 W m^(-2)(per unit total membrane area),much better than state-of-the-art membranes.This work provides a new strategy for the preparation of polyelectrolyte hydrogel-based ion-selective membranes,owning broad application prospects in the fields of osmotic energy collection,electrodialysis,flow battery and so on.
基金supported by the National Natural Science Foundation of China(Nos.22205084,42307566,22325303,22250003,T2222002,21991130,22032004)Fujian Provincial Natural Science Foundation of China(No.2022H6014)+4 种基金the China Postdoctoral Science Foundation(Nos.2023M741039,2023M742199)Project funded by National&Local Joint Engineering Research Center for Mineral Salt Deep Utilization(No.SF202303)State Key Laboratory of Efficient Utilization for Low Grade Phosphate Rock and Its Associated Resources WFKF(2023)013the Fundamental Research Funds for the Central Universities(Xiamen University,No.20720240053)State Key Laboratory of Vaccines for Infectious Diseases,Xiang An Biomedicine Laboratory(No.2023XAKJ0103074)。
文摘Single-molecule junctions are building blocks for constructing molecular devices.However,intermolecular interactions like winding bring additional interference among the surrounding molecules,which inhibits the intrinsic coherent transport through single-molecule junctions.Here,we employed a nanocavity(dimethoxypillar[5]arene,DMP[5]),which is analogous to electric cables,to confine the conformation of flexible chains(1,8-diaminooctane,DAO)via host-vip interaction.Single-molecule conductance measurements indicate that the conductance of DAO encapsulated with DMP[5]is as high as that of pure DAO,as reproduced by theoretical simulations.Intriguingly,the molecular lengths of the DAO encapsulated with DMP[5]increase from 1.13 nm to 1.46 nm compared with the pure DAO,indicating that DMP[5]keeps DAO upright-standing via the confinement effect.This work provides a new strategy to decouple the intermolecular interaction by employing an insulating sheath,enabling the high-density integration of single-molecule devices.
基金supported by the National Key Research and Development Program of China under Grant No.2022YFA1405000Innovation Program for Quantum Science and Technology under Grant No.2024ZD0300101the National Natural Science Foundation of China under Grant Nos.12274212,12174184,12347102。
文摘Active matter exhibits collective motions at various scales.Geometric confinement has been identified as an effective way to control and manipulate active fluids,with much attention given to external factors.However,the impact of the inherent properties of active particles on collective motion under confined conditions remains elusive.Here,we use a highly tunable active nematics model to study active systems under confinement,focusing on the effect of the self-driven speed of active particles.We identify three distinct states characterized by unique particle and flow fields within confined active nematic systems,among which circular rotation emerges as a collective motion involving rotational movement in both particle and flow fields.The theoretical phase diagram shows that increasing the self-driven speed of active particles significantly enhances the region of the circular rotation state and improves its stability.Our results provide insights into the formation of high quality vortices in confined active nematic systems.
