The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments...The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.展开更多
To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coa...To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection.展开更多
The visual cortex is an essential part of the brain for processing visual information.It exhibits structural and functional plasticity,which is crucial for adapting to complex visual environments.The quintessential ma...The visual cortex is an essential part of the brain for processing visual information.It exhibits structural and functional plasticity,which is crucial for adapting to complex visual environments.The quintessential manifestation of visual cortical plasticity is ocular dominance plasticity during the critical period,which involves numerous cellular and molecular events.While previous studies have emphasized the role of visual cortical neurons and their associated functional molecules in visual plasticity,recent findings have revealed that structural factors such as the extracellular matrix and glia are also involved.Investigating how these molecules interact to form a complex network that facilitates plasticity in the visual cortex is crucial to our understanding of the development of the visual system and the advancement of therapeutic strategies for visual disorders like amblyopia.展开更多
Computational fluid dynamics was used and a numerical simulation analysis of boiling heat transfer in microchannels with three depths and three cross-sectional profiles was conducted.The heat transfer coefficient and ...Computational fluid dynamics was used and a numerical simulation analysis of boiling heat transfer in microchannels with three depths and three cross-sectional profiles was conducted.The heat transfer coefficient and bubble generation process of three microchannel structures with a width of 80μm and a depth of 40,60,and 80μm were compared during the boiling process,and the factors influencing bubble generation were studied.A visual test bench was built,and test substrates of different sizes were prepared using a micro-nano laser.During the test,the behavior characteristics of the bubbles on the boiling surface and the temperature change of the heated wall were collected with a high-speed camera and a temperature sensor.It was found that the microchannel with a depth of 80μm had the largest heat transfer coefficient and shortest bubble growth period,the rectangular channel had a larger peak heat transfer coefficient and a lower frequency of bubble occurrence,while the V-shaped channel had the shortest growth period,i.e.,the highest frequency of bubble occurrence,but its heat transfer coefficient was smaller than that of the rectangular channel.展开更多
Due to its long lifespan and high sand-removal efficiency,gravel packing is one of the most applied sand control methods during the recovery of reservoirs with sanding problems.The blockage and retention of injected s...Due to its long lifespan and high sand-removal efficiency,gravel packing is one of the most applied sand control methods during the recovery of reservoirs with sanding problems.The blockage and retention of injected sand in a gravel pack is a complex process affected by multiple mechanisms.The majority of existing studies based on the phenomenological deep bed filtration(DBF)theory focused on the gravel pack’s overall permeability damage and failed to obtain the inner-pore particle distribution pattern.In this work,experiments and simulations were carried out to reveal the particle distribution in a gravel pack during flooding.In particular,through real-time monitoring of particle migration,the penetration depth and distribution pattern of invaded particles with different gravel-sand particle ratios,fluid viscosities and injection rates could be determined.By simplifying each unit bed element(UBE)into a pore-throat structure with four tunnels(two horizontals for discharge and two verticals for sedimentation),a new network simulation method,which combines deep bed filtration with a particle trajectory model,was implemented.Cross comparison of experimental and numerical results demonstrates the validity and accuracy of the model.展开更多
为探索出适用于一流本科课程教学的实践方式,文章针对"微机原理"实验课程,提出基于Visual Studio Code的实验教学模式。新模式弥补了传统实验教学的不足,能有效增强学生编写代码的兴趣,满足个性化需求,提高编程效率,提升教学...为探索出适用于一流本科课程教学的实践方式,文章针对"微机原理"实验课程,提出基于Visual Studio Code的实验教学模式。新模式弥补了传统实验教学的不足,能有效增强学生编写代码的兴趣,满足个性化需求,提高编程效率,提升教学质量。文章从实验项目安排、编程软件安装和实验操作等方面多角度介绍新模式对实验教学的支撑作用,为软件编程方面的实验教学工作提供新思路,进一步推进先进信息技术与实验教学的深度融合。展开更多
The objective of this paper is to investigate the effect of water temperature on cavitation characteristics in a turbopump inducer,a series of experiments at different temperatures have been conducted in a newly devel...The objective of this paper is to investigate the effect of water temperature on cavitation characteristics in a turbopump inducer,a series of experiments at different temperatures have been conducted in a newly developed visualization test facility.It is found that higher temperature shows little influence on the non-cavitation performance and breakdown characteristic in the investigated range.The relationship between cavitation development and pressure fluctuation has been discussed in detail.Higher temperature displays a remarkable stabilization effect on the cavitation excited pressure.In particular,the inception cavitation numbers of both the super-synchronous rotating cavitation and synchronous rotating cavitation are decreased at higher temperatures,and the corresponding frequencies are not affected,while the amplitudes are distinctly reduced,and the occurrence range of synchronous rotating cavitation is significantly narrowed.A generalized RayleighPlesset equation has been employed to account for the thermal effect on the bubble development,which may provide a deep insight in understanding the experimental results.Thermal effect is found to act as a remarkable dissipation mechanism to suppress the bubble growth,smooth the collapse.In particular,the excited pressure during collapse is smaller at higher temperatures,which may lead to the stabilization effect of high temperature in this study.展开更多
During the displacement of water plugging with binary flooding in internally heterogeneous reservoirs,it is essential to understand the distributions of remaining oil as well as the oil displacement mechanisms at diff...During the displacement of water plugging with binary flooding in internally heterogeneous reservoirs,it is essential to understand the distributions of remaining oil as well as the oil displacement mechanisms at different stages.In this study,two types of internally heterogeneous systems,i.e.,vertical and horizontal wells are investigated experimentally through a microscopic approach.The results show that plugging agent types have a greater impact on oil recovery than well types,and foam injection can enhance oil recovery more effectively than gel injection.Additionally,the injection sequence of plugging agents significantly affects oil displacement efficiency.Injecting gel after foam is more beneficial.According to the present results,the main formation mechanisms of remaining oil in each displacement stage are influenced by:capillary force,viscous force,inertial force,shear force,microscopic fingering&channeling.展开更多
As typical visual culture symbol of China, the visual image of Sun Wukong firstly appeared on the mural of Yulin Caves of Dunhuang in Western Xia regime and the story of Monk Tang and his prentices on the mural in Yua...As typical visual culture symbol of China, the visual image of Sun Wukong firstly appeared on the mural of Yulin Caves of Dunhuang in Western Xia regime and the story of Monk Tang and his prentices on the mural in Yuan Dynasty. Up to Yuan Dynasty, it became very popular. Since the novel Pilgrimage to the West was published, the visual image of Sun Wukong has appeared in the visual carriers of wood block, colored drawing, paper-cut, traditional Chinese opera, film, television, ad, cartoon and so on. European countries, America, Japan and South Korea use advanced film and TV technology and digital technology to deduce, model, adapt and simulate the visual image of Sun Wukong. This paper investigates the construction of the visual image of Sun Wukong in China and extraterritorial countries and regions, tries to explore Chinese ＂visual＂ experience in mediaeval times and especially modern times and seeks a clue for understanding Chinese problem of visual expression.展开更多
Spontaneous activity in the brain maintains an internal structured pattern that reflects the external environment,which is essential for processing information and developing perception and cognition.An essential prer...Spontaneous activity in the brain maintains an internal structured pattern that reflects the external environment,which is essential for processing information and developing perception and cognition.An essential prerequisite of spontaneous activity for perception is the ability to reverberate external information,such as by potentiation.Yet its role in the processing of potentiation in mouse superior colliculus(SC)neurons is less studied.Here,we used electrophysiological recording,optogenetics,and drug infusion methods to investigate the mechanism of potentiation in SC neurons.We found that visual experience potentiated SC neurons several minutes later in different developmental stages,and the similarity between spontaneous and visually-evoked activity increased with age.Before eye-opening,activation of retinal ganglion cells that expressed ChR2 also induced the potentiation of spontaneous activity in the mouse SC.Potentiation was dependenton stimulus number and showed feature selectivity for direction and orientation.Optogenetic activation of parvalbumin neurons in the SC attenuated the potentiation induced by visual experience.Furthermore,potentiation in SC neurons was blocked by inhibiting the glutamate transporter GLT1.These results indicated that the potentiation induced by a visual stimulus might play a key role in shaping the internal representation of the environment,and serves as a carrier for short-term memory consolidation.展开更多
Corrosion leakages often occur in the air cooler of a hydrocracking unit,with the failure sites mainly located in the entrance area of the tubes.An analysis of the macroscopic morphology and corrosion products confirm...Corrosion leakages often occur in the air cooler of a hydrocracking unit,with the failure sites mainly located in the entrance area of the tubes.An analysis of the macroscopic morphology and corrosion products confirmed that the damage was caused by erosion-corrosion(E-C).Numerical and experimental methods were applied to investigate the E-C mechanism in the air cooler.Computational fluid dynamics(CFD)was used to calculate the hydrodynamic parameters of the air cooler.The results showed that there was a biased flow in the air cooler,which led to a significant increase in velocity,turbulent kinetic energy and wall shear within 0.2 m of the tube entrance.A visualization experiment was then performed to determine the principles of migration and transformation of multiphase flow in the air cooler tubes.Various flow patterns(pure droplet flow,mist flow,and annular flow)and their evolutionary processes were clearly depicted experimentally.The initiation mechanism and processes leading to the development of E-C in the air cooler were also determined.This study provided a comprehensive explanation for the E-C failures that occur in air coolers during operation.展开更多
The paper examines the assignment of the visual experience in the context of interrelation between civilization and art. Civilization is defined as ＂the survival of the weak＂. It is stressed that this definition can...The paper examines the assignment of the visual experience in the context of interrelation between civilization and art. Civilization is defined as ＂the survival of the weak＂. It is stressed that this definition can be applied to man, animal and every living being. Lie as ＂someone else＇s truth＂ and art as ＂the process of the creation of ＇copies of the copies of nature＇＂ are considered to be the weak man＇s tools for survival. The author argues that purpose of erotic scenes and scenes of hunting （death and violence） both in the past and in the present is the excitation at the woman of desire to reproduction.展开更多
Extended experiments were conducted on the oscillation characteristics of merged liquid slugs in a horizontally oriented polymer pulsating heat pipe(PHP).The PHP’s serpentine channel comprised 14 parallel channels wi...Extended experiments were conducted on the oscillation characteristics of merged liquid slugs in a horizontally oriented polymer pulsating heat pipe(PHP).The PHP’s serpentine channel comprised 14 parallel channels with a width of 1.3 mm and a height of 1.1 mm.The evaporator and condenser sections were 25 and 50 mm long,respectively,and the adiabatic section in between was 75mmlong.Using a plastic 3D printer and semi-transparent filament made from acrylonitrile butadiene styrene,the serpentine channel was printed directly onto a thin polycarbonate sheet to form the PHP.The PHP was charged with hydrofluoroether-7100.In the experiments,the evaporator section was heated,and the condenser section was cooled using high-temperature and low-temperature thermostatic baths,respectively.Flow patterns of the working fluid were obtained with temperature distributions of the PHP.A mathematical model was developed to analyze the flow patterns.Themerged liquid slugs were observed in every two channels,and their oscillation characteristics were found to be approximately the same in time and space.It was also found that the oscillations of the merged liquid slugs became slower,but the heat transfer rate of the PHP increased with a decrease in the filling ratio of the working fluid.This is because vapor condensation was enhanced in vapor plugs as the filling ratio decreased.However,the filling ratio had a lower limit,and the heat transfer rate was maximum when the filling ratio was 40.6%in the present experimental range.展开更多
AIM：To determine whether gypenosides have protective effects in experimental autoimmune optic neuritis（EAON）.METHODS：Mice were randomly divided into seven groups：control group,model group,three different density ...AIM：To determine whether gypenosides have protective effects in experimental autoimmune optic neuritis（EAON）.METHODS：Mice were randomly divided into seven groups：control group,model group,three different density gypenosides monotherapy,methylprednisolone monotherapy,combination of gypenosides and methylprednisolone group.The control group was subcutaneously injected with oil emulsion adjuvant and all other groups were subcutaneously immunized with an emulsified mixture of myelin oligodendrocyte glycoprotein（MOG） 35-55 peptide to induce EAON.Mice in the gypenosides groups were administered injections daily with three concentrations（15 mg/kg,30 mg/kg,45 mg/kg） of gypenosides respectively.Mice in the methylprednisolone group and the combination treatment group were injected daily with methylprednisolone（20 mg/kg） or methylprednisolone（20 mg/kg） ＋ gypenosides（30 mg/kg）,respectively.After MOG immunization,visual evoked potential（VEP）,optical coherence tomography（OCT）,and histopathologic examination were performed at 14,20,30,and 40 d post-inoculation（p.i.）.All results were expressed as mean±SEM.The data were evaluated by oneway ANOVA followed by Tukey or Games-Howell test.RESULTS：Compared with the control group,p2 latency was prolonged in the model group（P=0.041）.Combination treatment can alleviated the change in VEP at 20 d p.i.（P=0.012）.Average peripapillary retinal nerve fiber layer（RNFL） thickness was reduced in the model group（P= 0.000,30d;P=0.000,40d） and gypenosides treatment remarkably diminished the degree of RNFL degenerationat 30 d and 40 d p.i（P=0.000,30d;P=0.000,40d）.The pathomorphological results showed a decrease in demyelination（P=0.020） and inflammatory reactions in the combination group compared with the model group（20d p.i.）.Gypenosides treatment also alleviated the degree of axonal loss（40d p.i.）（P=0.003）.CONCLUSION：Treatment with gypenosides exerts protective effects on retinal nerve fibers and axons in EAON.When combined with gypenosides,methylprednisolone reduces demyelination in the acute stage of EAON.展开更多
基金financially supported by the National Natural Science Foundation of China(No.U20B6003)the China Scholarship Council(No.202306440015)a project of the China Petroleum&Chemical Corporation(No.P22174)。
文摘The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.
基金Supported by the National Basic Research Program of China under Grant No 2014CB340102
文摘To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection.
基金supported by the National Natural Science Foundation of China(81770956,81371049,32471055 and 82171090)Project of Tianjin 131 Innovative Talent Team(201936)+4 种基金the Science and Technology Planning Project of Tianjin(21JCYBJC00780)the Science and Technology Fund for Health of Tianjin(TJWJ2023ZD008)Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)ZJLab,Shanghai Center for Brain Science and Brain-Inspired Technology,the Lingang Laboratory(LG-QS-202203-12)Tianjin Key Medical Discipline(Specialty)Construction Project(TJYXZDXK‑016A).
文摘The visual cortex is an essential part of the brain for processing visual information.It exhibits structural and functional plasticity,which is crucial for adapting to complex visual environments.The quintessential manifestation of visual cortical plasticity is ocular dominance plasticity during the critical period,which involves numerous cellular and molecular events.While previous studies have emphasized the role of visual cortical neurons and their associated functional molecules in visual plasticity,recent findings have revealed that structural factors such as the extracellular matrix and glia are also involved.Investigating how these molecules interact to form a complex network that facilitates plasticity in the visual cortex is crucial to our understanding of the development of the visual system and the advancement of therapeutic strategies for visual disorders like amblyopia.
基金supported by the National Natural Science Foundation of China Youth Program(Grant No.51905328).
文摘Computational fluid dynamics was used and a numerical simulation analysis of boiling heat transfer in microchannels with three depths and three cross-sectional profiles was conducted.The heat transfer coefficient and bubble generation process of three microchannel structures with a width of 80μm and a depth of 40,60,and 80μm were compared during the boiling process,and the factors influencing bubble generation were studied.A visual test bench was built,and test substrates of different sizes were prepared using a micro-nano laser.During the test,the behavior characteristics of the bubbles on the boiling surface and the temperature change of the heated wall were collected with a high-speed camera and a temperature sensor.It was found that the microchannel with a depth of 80μm had the largest heat transfer coefficient and shortest bubble growth period,the rectangular channel had a larger peak heat transfer coefficient and a lower frequency of bubble occurrence,while the V-shaped channel had the shortest growth period,i.e.,the highest frequency of bubble occurrence,but its heat transfer coefficient was smaller than that of the rectangular channel.
基金supported by Outstanding Youth Fund of Shandong Province(ZR2020YQ36).
文摘Due to its long lifespan and high sand-removal efficiency,gravel packing is one of the most applied sand control methods during the recovery of reservoirs with sanding problems.The blockage and retention of injected sand in a gravel pack is a complex process affected by multiple mechanisms.The majority of existing studies based on the phenomenological deep bed filtration(DBF)theory focused on the gravel pack’s overall permeability damage and failed to obtain the inner-pore particle distribution pattern.In this work,experiments and simulations were carried out to reveal the particle distribution in a gravel pack during flooding.In particular,through real-time monitoring of particle migration,the penetration depth and distribution pattern of invaded particles with different gravel-sand particle ratios,fluid viscosities and injection rates could be determined.By simplifying each unit bed element(UBE)into a pore-throat structure with four tunnels(two horizontals for discharge and two verticals for sedimentation),a new network simulation method,which combines deep bed filtration with a particle trajectory model,was implemented.Cross comparison of experimental and numerical results demonstrates the validity and accuracy of the model.
文摘为探索出适用于一流本科课程教学的实践方式,文章针对"微机原理"实验课程,提出基于Visual Studio Code的实验教学模式。新模式弥补了传统实验教学的不足,能有效增强学生编写代码的兴趣,满足个性化需求,提高编程效率,提升教学质量。文章从实验项目安排、编程软件安装和实验操作等方面多角度介绍新模式对实验教学的支撑作用,为软件编程方面的实验教学工作提供新思路,进一步推进先进信息技术与实验教学的深度融合。
文摘The objective of this paper is to investigate the effect of water temperature on cavitation characteristics in a turbopump inducer,a series of experiments at different temperatures have been conducted in a newly developed visualization test facility.It is found that higher temperature shows little influence on the non-cavitation performance and breakdown characteristic in the investigated range.The relationship between cavitation development and pressure fluctuation has been discussed in detail.Higher temperature displays a remarkable stabilization effect on the cavitation excited pressure.In particular,the inception cavitation numbers of both the super-synchronous rotating cavitation and synchronous rotating cavitation are decreased at higher temperatures,and the corresponding frequencies are not affected,while the amplitudes are distinctly reduced,and the occurrence range of synchronous rotating cavitation is significantly narrowed.A generalized RayleighPlesset equation has been employed to account for the thermal effect on the bubble development,which may provide a deep insight in understanding the experimental results.Thermal effect is found to act as a remarkable dissipation mechanism to suppress the bubble growth,smooth the collapse.In particular,the excited pressure during collapse is smaller at higher temperatures,which may lead to the stabilization effect of high temperature in this study.
文摘During the displacement of water plugging with binary flooding in internally heterogeneous reservoirs,it is essential to understand the distributions of remaining oil as well as the oil displacement mechanisms at different stages.In this study,two types of internally heterogeneous systems,i.e.,vertical and horizontal wells are investigated experimentally through a microscopic approach.The results show that plugging agent types have a greater impact on oil recovery than well types,and foam injection can enhance oil recovery more effectively than gel injection.Additionally,the injection sequence of plugging agents significantly affects oil displacement efficiency.Injecting gel after foam is more beneficial.According to the present results,the main formation mechanisms of remaining oil in each displacement stage are influenced by:capillary force,viscous force,inertial force,shear force,microscopic fingering&channeling.
基金Acknowledgements： This paper was sponsored by China National Social Science Foundation ＂Research on the Fundamental Problems of the Contemporary Aesthetics and Criticism Patterns＂ （15ZDB023）.
文摘As typical visual culture symbol of China, the visual image of Sun Wukong firstly appeared on the mural of Yulin Caves of Dunhuang in Western Xia regime and the story of Monk Tang and his prentices on the mural in Yuan Dynasty. Up to Yuan Dynasty, it became very popular. Since the novel Pilgrimage to the West was published, the visual image of Sun Wukong has appeared in the visual carriers of wood block, colored drawing, paper-cut, traditional Chinese opera, film, television, ad, cartoon and so on. European countries, America, Japan and South Korea use advanced film and TV technology and digital technology to deduce, model, adapt and simulate the visual image of Sun Wukong. This paper investigates the construction of the visual image of Sun Wukong in China and extraterritorial countries and regions, tries to explore Chinese ＂visual＂ experience in mediaeval times and especially modern times and seeks a clue for understanding Chinese problem of visual expression.
基金supported by the National Natural Science Foundation of China(31771195,81790640 and 82021002)a Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)+1 种基金ZJLab,Key Scientific Technological Innovation Research Project of the Ministry of Education,Sanming Project of Medicine in Shenzhen(SZSM202011015)Shanghai Health and Family Planning Commission(20164Y0096,20184Y0184)。
文摘Spontaneous activity in the brain maintains an internal structured pattern that reflects the external environment,which is essential for processing information and developing perception and cognition.An essential prerequisite of spontaneous activity for perception is the ability to reverberate external information,such as by potentiation.Yet its role in the processing of potentiation in mouse superior colliculus(SC)neurons is less studied.Here,we used electrophysiological recording,optogenetics,and drug infusion methods to investigate the mechanism of potentiation in SC neurons.We found that visual experience potentiated SC neurons several minutes later in different developmental stages,and the similarity between spontaneous and visually-evoked activity increased with age.Before eye-opening,activation of retinal ganglion cells that expressed ChR2 also induced the potentiation of spontaneous activity in the mouse SC.Potentiation was dependenton stimulus number and showed feature selectivity for direction and orientation.Optogenetic activation of parvalbumin neurons in the SC attenuated the potentiation induced by visual experience.Furthermore,potentiation in SC neurons was blocked by inhibiting the glutamate transporter GLT1.These results indicated that the potentiation induced by a visual stimulus might play a key role in shaping the internal representation of the environment,and serves as a carrier for short-term memory consolidation.
基金supported by the National Key R&D Program of China(2021YFB3301100)Beijing University of Chemical Technology Interdisciplinary Program(XK2023-07).
文摘Corrosion leakages often occur in the air cooler of a hydrocracking unit,with the failure sites mainly located in the entrance area of the tubes.An analysis of the macroscopic morphology and corrosion products confirmed that the damage was caused by erosion-corrosion(E-C).Numerical and experimental methods were applied to investigate the E-C mechanism in the air cooler.Computational fluid dynamics(CFD)was used to calculate the hydrodynamic parameters of the air cooler.The results showed that there was a biased flow in the air cooler,which led to a significant increase in velocity,turbulent kinetic energy and wall shear within 0.2 m of the tube entrance.A visualization experiment was then performed to determine the principles of migration and transformation of multiphase flow in the air cooler tubes.Various flow patterns(pure droplet flow,mist flow,and annular flow)and their evolutionary processes were clearly depicted experimentally.The initiation mechanism and processes leading to the development of E-C in the air cooler were also determined.This study provided a comprehensive explanation for the E-C failures that occur in air coolers during operation.
文摘The paper examines the assignment of the visual experience in the context of interrelation between civilization and art. Civilization is defined as ＂the survival of the weak＂. It is stressed that this definition can be applied to man, animal and every living being. Lie as ＂someone else＇s truth＂ and art as ＂the process of the creation of ＇copies of the copies of nature＇＂ are considered to be the weak man＇s tools for survival. The author argues that purpose of erotic scenes and scenes of hunting （death and violence） both in the past and in the present is the excitation at the woman of desire to reproduction.
基金supported by JSPS KAKENHI Grant Number 22K03947.
文摘Extended experiments were conducted on the oscillation characteristics of merged liquid slugs in a horizontally oriented polymer pulsating heat pipe(PHP).The PHP’s serpentine channel comprised 14 parallel channels with a width of 1.3 mm and a height of 1.1 mm.The evaporator and condenser sections were 25 and 50 mm long,respectively,and the adiabatic section in between was 75mmlong.Using a plastic 3D printer and semi-transparent filament made from acrylonitrile butadiene styrene,the serpentine channel was printed directly onto a thin polycarbonate sheet to form the PHP.The PHP was charged with hydrofluoroether-7100.In the experiments,the evaporator section was heated,and the condenser section was cooled using high-temperature and low-temperature thermostatic baths,respectively.Flow patterns of the working fluid were obtained with temperature distributions of the PHP.A mathematical model was developed to analyze the flow patterns.Themerged liquid slugs were observed in every two channels,and their oscillation characteristics were found to be approximately the same in time and space.It was also found that the oscillations of the merged liquid slugs became slower,but the heat transfer rate of the PHP increased with a decrease in the filling ratio of the working fluid.This is because vapor condensation was enhanced in vapor plugs as the filling ratio decreased.However,the filling ratio had a lower limit,and the heat transfer rate was maximum when the filling ratio was 40.6%in the present experimental range.
基金Supported by the National Natural Science Foundation of China(No.81260149No.81360152No.81560162)
文摘AIM：To determine whether gypenosides have protective effects in experimental autoimmune optic neuritis（EAON）.METHODS：Mice were randomly divided into seven groups：control group,model group,three different density gypenosides monotherapy,methylprednisolone monotherapy,combination of gypenosides and methylprednisolone group.The control group was subcutaneously injected with oil emulsion adjuvant and all other groups were subcutaneously immunized with an emulsified mixture of myelin oligodendrocyte glycoprotein（MOG） 35-55 peptide to induce EAON.Mice in the gypenosides groups were administered injections daily with three concentrations（15 mg/kg,30 mg/kg,45 mg/kg） of gypenosides respectively.Mice in the methylprednisolone group and the combination treatment group were injected daily with methylprednisolone（20 mg/kg） or methylprednisolone（20 mg/kg） ＋ gypenosides（30 mg/kg）,respectively.After MOG immunization,visual evoked potential（VEP）,optical coherence tomography（OCT）,and histopathologic examination were performed at 14,20,30,and 40 d post-inoculation（p.i.）.All results were expressed as mean±SEM.The data were evaluated by oneway ANOVA followed by Tukey or Games-Howell test.RESULTS：Compared with the control group,p2 latency was prolonged in the model group（P=0.041）.Combination treatment can alleviated the change in VEP at 20 d p.i.（P=0.012）.Average peripapillary retinal nerve fiber layer（RNFL） thickness was reduced in the model group（P= 0.000,30d;P=0.000,40d） and gypenosides treatment remarkably diminished the degree of RNFL degenerationat 30 d and 40 d p.i（P=0.000,30d;P=0.000,40d）.The pathomorphological results showed a decrease in demyelination（P=0.020） and inflammatory reactions in the combination group compared with the model group（20d p.i.）.Gypenosides treatment also alleviated the degree of axonal loss（40d p.i.）（P=0.003）.CONCLUSION：Treatment with gypenosides exerts protective effects on retinal nerve fibers and axons in EAON.When combined with gypenosides,methylprednisolone reduces demyelination in the acute stage of EAON.
