While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfa...While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.展开更多
Lacustrine groundwater discharge(LGD)plays an important role in water resources management.Previous studies have focused on LGD process in a single lake,but the differences in LGD process within the same region have n...Lacustrine groundwater discharge(LGD)plays an important role in water resources management.Previous studies have focused on LGD process in a single lake,but the differences in LGD process within the same region have not been thoroughly investigated.In this study,multiple tracers(hydrochemistry,𝛿D,𝛿18O and 222Rn)were used to compare mechanisms of LGD in Daihai and Ulansuhai Lake in Inner Mongoli1,Northwest China.The hydrochemical types showed a trend from groundwater to lake water,indicating a hydraulic connection between them.In addition,the𝛿D and𝛿18O values of sediment pore water were between the groundwater and lake water,indicating the LGD processes.The radon mass balance model was used to estimate the average groundwater discharge rates of Daihai and Ulansuhai Lake,which were 2.79 mm/day and 3.02 mm/day,respectively.The total nitrogen(TN),total phosphorus(TP),and fluoride inputs associated with LGD in Daihai Lake accounted for 97.52%,96.59%,and 95.84%of the total inputs,respectively.In contrast,TN,TP and fluoride inputs in Ulansuhai Lake were 53.56%,40.98%,and 36.25%,respectively.This indicates that the pollutant inputs associated with LGD posed a potential threat to the ecological stability of Daihai and Ulansuhai Lake.By comparison,the differences of LGD process and associated pollutant flux were controlled by hydrogeological conditions,lakebed permeability and human activities.This study provides a reference for water resources management in Daihai and Ulansuhai Lake basins while improving the understanding of LGD in the Yellow River basin.展开更多
Based on a homemade novel dielectric barrier discharge actuator with a rotating high-voltage electrode, this study investigates the influence of electrode rotating speed on the discharge characteristics, and the mecha...Based on a homemade novel dielectric barrier discharge actuator with a rotating high-voltage electrode, this study investigates the influence of electrode rotating speed on the discharge characteristics, and the mechanisms of discharge process under rotary conditions are discussed. The results demonstrate that when the high-voltage electrode is rotating,the distribution patterns of dielectric barrier discharge and the parameters of micro-discharge channels exhibit significant changes. Under a low rotating speed, the discharge patterns present as a series of separated discharge channels, resulting in uniform charge distribution but uneven electric field distribution in the gap. As the rotating speed increases, the electric field and the discharge channels will be affected by the rotation, so the electric field is more evenly distributed in the gap, and the discharge mode changes to a quasi-uniform discharge. With increasing distance from the rotation axis, the electric field strength gradually decreases, and the electric field force experienced by the micro-discharge channels during its formation weakens. Consequently, the average size of the micro-discharge channels increases, indicating that these channels are gradually stretched. The rotation of the electrode generates a significant number of accumulated charges, impacting the number of micro-discharge channels. The number of micro-discharge channels at the center of the electrode increases with rotating speed;however, due to channel stretching, the average size of the micro-discharge channels at the edge of the electrode also increases, leading to a decrease in their overall quantity. The research results reveal the significant impact of the electrode rotation on the characteristics of discharge channels, providing a theoretical basis for further optimal design of the rotating dielectric barrier discharge in various application.展开更多
Flexible surface micro-discharge plasma is a non-thermal plasma technique used for treating wounds in a painless way, with significant efficacy for chronic or hard-to-heal wounds. In this study, a confined space was d...Flexible surface micro-discharge plasma is a non-thermal plasma technique used for treating wounds in a painless way, with significant efficacy for chronic or hard-to-heal wounds. In this study, a confined space was designed to simulate wound conditions, with gelatin used to simulate wound tissue. The distinction between open and confined spaces was explored, and the effects of temperature, humidity, discharge power and the gap size within the confined space on the plasma characteristics were analyzed. It was found that temperature, humidity and discharge power are important factors that affect the concentration distribution of active components and the mode transition between ozone and nitrogen oxides. Compared to open space, the concentration of ozone in confined space was relatively lower, which facilitated the formation of nitrogen oxides. In open space, the discharge was dominated by ozone initially. As the temperature,humidity and discharge power increased, nitrogen oxides in the gas-phase products were gradually detected. In confined space, nitrogen oxides can be detected at an early stage and at much higher concentrations than ozone concentration. Furthermore, as the gap of the confined space decreased, the concentration of ozone was observed to decrease while that of nitrate increased, and the rate of this concentration change was further accelerated at higher temperature and higher power. It was shown that ozone concentration decreased from 0.11 to 0.03 μmol and the nitrate concentration increased from 20.5 to 24.5 μmol when the spacing in the confined space was reduced from 5 to 1 mm, the temperature of the external discharge was controlled at 40 ℃, and the discharge power was 12 W. In summary, this study reveals the formation and transformation mechanisms of active substances in air surface micro-discharge plasma within confined space, providing foundational data for its medical applications.展开更多
This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca(AZ63X)anode for Mg-air battery.An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but...This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca(AZ63X)anode for Mg-air battery.An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but does not hinder the transfer of the electrons at the interface.Fortunately,the addition of Ce,La,and Ca into AZ63 alloy achieves this goal.The Mg-air battery with AZ63X anode in 3.5%Na Cl has an ultrahigh anodic efficiency of 85.7±1.7%and energy-density of 2431±53 mWh g^(-1)with the unique discharge product film,surpassing the values of most reported Mg-air batteries.Furthermore,the alloying elements reduce the anode delamination effect significantly by transforming the block Mg_(17)Al_(12)phase into the connected Mg_(17)Al_(12)structure and fine rod Al_(2)RE and Al_(2)Ca.展开更多
To explore the electrostatic discharge behavior of charged powders in industrial silos,discharge experiments are conducted based on a full-size industrial silo discharge platform.Electrostatic discharge mode,frequency...To explore the electrostatic discharge behavior of charged powders in industrial silos,discharge experiments are conducted based on a full-size industrial silo discharge platform.Electrostatic discharge mode,frequency,and energy are investigated for powders of different polarities.Although the powders have low charge-to-mass ratios(+0.087μC/kg for the positively charged powders and−0.26μC/kg for the negatively charged ones),electrostatic discharges occur approximately every 10 s,with the maximum discharge energy being 800 mJ.Powder polarity considerably influences discharge energy.The positive powders exhibit higher discharge energy than the negative ones,although discharge frequency remains similar for both.Effects of powder charge,humidity,and mass flow on discharge frequency and discharge energy are quantitatively analyzed,providing important insights for the improvement of safety in industrial powder handling.展开更多
Objective:To investigate the application effect of the discharge preparation plan based on the ADOPT nursing model in patients with first-visit ischemic stroke.Methods:Eighty patients with first-visit ischemic stroke ...Objective:To investigate the application effect of the discharge preparation plan based on the ADOPT nursing model in patients with first-visit ischemic stroke.Methods:Eighty patients with first-visit ischemic stroke admitted to our hospital from June 1,2024 to November 31,2024 were selected and divided into a control group(June 1,2024 to August 30,2024)and an intervention group(September 1,2024 to November 31,2024)according to different admission times,with 40 cases in each group.The control group received routine care and discharge guidance,while the intervention group received a discharge preparation plan based on the ADOPT model on the basis of routine care.The discharge readiness[Discharge Readiness Scale(RHDS)]of patients on the day of discharge was compared.Self-efficacy at 3 months after discharge[evaluated using the Chronic Disease Self-Efficacy Scale(SECD6)],activities of daily living[evaluated using the Barthel index(BI)],blood glucose and blood pressure indicators(diastolic blood pressure,systolic blood pressure,FPG,2 h PG),and readmission rate within 3 months after discharge were also compared between the two groups.Results:On the day of discharge,the RHDS-related dimension scores of the intervention group were higher than those of the control group(t=17.993,8.560,10.243,p<0.05);Three months after discharge,the SECD6 score and BI score of the intervention group were higher than those of the control group(t=8.910,10.899,both p<0.05);Systolic blood pressure,diastolic blood pressure,FPG and 2h PG in the intervention group were lower than those in the control group(t=8.868,4.794,3.829,7.121,all p<0.05);Within 3 months after discharge,the readmission rate of the intervention group was lower than that of the control group(χ^(2)=5.165,2 p<0.05).Conclusion:The discharge preparation plan based on the ADOPT nursing model,when applied to patients with first-visit ischemic stroke,can not only enhance self-efficacy and discharge preparation,improve activities of daily living,but also optimize blood glucose and blood pressure indicators and reduce the readmission rate,which is worthy of reference.展开更多
Research has been carried out on a hybrid discharge ion thruster,aiming to combine the advantages of Direct Current(DC)discharge ion thrusters(known for their high thrust density and high power supply efficiency)with ...Research has been carried out on a hybrid discharge ion thruster,aiming to combine the advantages of Direct Current(DC)discharge ion thrusters(known for their high thrust density and high power supply efficiency)with microwave discharge ion thrusters(which do not require a hollow cathode and are capable of efficient ionization at low pressures).Comparative experiments with different anode structures and single-probe diagnostics revealed that applying a DC bias voltage created a new ionization zone based on microwave discharge.This DC bias increased the sheath potential of the screen grid and led to an elevation in electron temperature and plasma density.It is speculated that the reduced loss of high-energy electrons generated by microwave discharge at the screen grid is the primary reason for the enhanced discharge.By adding a DC bias of approximately 50 V to the microwave discharge,the screen grid current was doubled without a significant increase in discharge power consumption.Under appropriate bias voltages that consider minimizing ion sputtering,DC bias holds promise as a design approach to increase the extracted beam current in microwave ion thrusters.展开更多
As a popular approach to producing atmospheric pressure non-thermal plasma,dielectric barrier discharge(DBD)has been extensively used in various application fields.In this paper,DBD with wavy dielectric layers is nume...As a popular approach to producing atmospheric pressure non-thermal plasma,dielectric barrier discharge(DBD)has been extensively used in various application fields.In this paper,DBD with wavy dielectric layers is numerically simulated in atmospheric pressure helium mixed with trace nitrogen based on a fluid model.With varying relative position(phase difference(Δφ))of the wavy surfaces,there is a positive discharge and a negative discharge per voltage cycle,each of which consists of a pulse stage and a hump stage.For the pulse stage,maximal current increases with increasingΔφ.Results show that DBD with the wavy surfaces appears as discrete micro-discharges(MDs),which are self-organized to different patterns with varyingΔφ.The MDs are vertical and uniformly-spaced withΔφ=0,which are self-organized in pairs withΔφ=π/4.These MD pairs are merged into some bright wide MDs withΔφ=π/2.In addition,narrow MDs appear between tilted wide MDs withΔφ=3π/4.WithΔφ=π,the pattern is composed of wide and narrow MDs,which are vertical and appear alternately.To elucidate the formation mechanism of the patterns with differentΔφ,temporal evolutions of electron density and electric field are investigated for the positive discharge.Moreover,surface charge on the wavy dielectric layers has also been compared with differentΔφ.展开更多
This paper describes the realization of a homogeneous dielectric barrier discharge(DBD)in argon at atmospheric pressure.The effect of the morphology of the dielectric surface(especially the dielectric surface covered ...This paper describes the realization of a homogeneous dielectric barrier discharge(DBD)in argon at atmospheric pressure.The effect of the morphology of the dielectric surface(especially the dielectric surface covered by hollow ceramic beads(99%Al_(2)O_(3))with different diameters)on discharge is investigated.With different dielectrics,the argon DBD presents two discharge modes:a filamentary mode and a homogeneous mode.Fast photography shows that the filamentary mode operates in a streamer discharge,and the homogeneous mode operates in a Townsend discharge regime.It is found that a homogeneous discharge can be generated within a certain voltage range.The voltage amplitude range decreases,and the breakdown voltage increases with the increase in the mean diameter of the ceramic beads.Waveforms of the total current and optical emission signal present stochastic pulses per half voltage cycle for the filamentary mode,whereas there is one single hump per half voltage cycle for the homogeneous mode.In the homogeneous mode,the intensity of the optical emission decreases with the mean diameter of the ceramic beads.The optical emission spectrum is mainly composed of atomic lines of argon and the second positive system of molecular nitrogen.It reveals that the electron density decreases with the increasing mean diameter of the ceramic beads.The vibrational temperature increases with the increasing mean diameter of the ceramic beads.It is believed that a large number of microdischarges are formed,and smaller ceramic beads have a larger activation surface area and more point discharge.Electrons liberated in the shallow well and electrons generated from microdischarges can increase the secondary electron emission coefficient of the cathode and provide initial electrons for discharge continuously.Therefore,the breakdown electric field is reduced,which contributes to easier generation of homogeneous discharge.This is confirmed by the simulation results.展开更多
A novel precipitate-free Mg-0.1Sn anode with a homogeneous equal-axis grain structure was developed and rolled successfully at 573 K.Electrochemical test results indicate that the Mg-0.1Sn alloy exhibits enhanced anod...A novel precipitate-free Mg-0.1Sn anode with a homogeneous equal-axis grain structure was developed and rolled successfully at 573 K.Electrochemical test results indicate that the Mg-0.1Sn alloy exhibits enhanced anode dissolution kinetics.A Mg-air battery prepared using this anode exhibits a cell voltage of 1.626 V at 0.5 mA/cm^(2),reasonable anodic efficiency of 58.17%,and good specific energy of 1730.96 mW·h/g at 10 mA/cm^(2).This performance is attributed to the effective reactive anode surface,the suppressed chunk effect,and weak self-corrosion owing to the homogeneous basal texture.展开更多
With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater str...With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater\|discharge coefficient, complete wastewater\|discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in Beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city.展开更多
To enhance the operational capacity and space utilization of baffle-drop shafts,this study improved the traditional baffle-drop shaft by expanding the wet-side space,incorporating large rotation-angle baffles,and inst...To enhance the operational capacity and space utilization of baffle-drop shafts,this study improved the traditional baffle-drop shaft by expanding the wet-side space,incorporating large rotation-angle baffles,and installing overflow holes in the dividing wall.A three-dimensional turbulent model was developed using ANSYS Fluent to simulate the hydraulic characteristics of both traditional and new baffle-drop shafts across various flow rates.The simulation results demonstrated that the new shaft design allowed for discharge from both the wet and dry sides,significantly improving operational capacity,with the dry side capable of handling 40%of the inlet flow.Compared to the traditional shaft,the new design reduced shaft wall pressures and decreased the mean and standard deviation of pressure on typical baffles by 21%and 63%,respectively,therefore enhancing structural safety.Additionally,the new shaft achieved a 2%-12%higher energy dissipation rate than the traditional shaft across different flow rates.This study offers valuable insights for the design and optimization of drop shafts in deep tunnel drainage systems.展开更多
The deposition layer on the discharge channel wall of a Hall thruster after long-term operation occasionally detaches from the wall and interferes with the plasma inside the channel,resulting in current pulse and thre...The deposition layer on the discharge channel wall of a Hall thruster after long-term operation occasionally detaches from the wall and interferes with the plasma inside the channel,resulting in current pulse and threatening the power supply.To understand the generation mechanism of the current pulse,the interaction between the peeling material and the channel plasma was studied by the particle-in-cell and Monte Carlo collision(PIC/MCC)method.The plasma evolution and distribution in the Hall thruster channel when peeling material existed were simulated.Simulation results show that the peeling material changes the electron transportation and ionization,and the effects are related to the position of the peeling material.When the peeling material invades the zone where the ionization rate is originally the highest without peeling material,the ionization process is almost terminated.The ionization suppression by the peeling material will cause the propellant gas to refill the channel exit.As the peeling material moves away,gas discharge is induced near the channel exit,resulting in anode current pulse.展开更多
In this work,a series of experiments are carried out to investigate the effect of charge/discharge rates(1,2,3 and 4 C)and state of charges(SOCs,namely 0%,50%,75%and 100%)on thermal runaway(TR)and fire behavior of lit...In this work,a series of experiments are carried out to investigate the effect of charge/discharge rates(1,2,3 and 4 C)and state of charges(SOCs,namely 0%,50%,75%and 100%)on thermal runaway(TR)and fire behavior of lithium iron phosphate(LFP)batteries.The TR process caused by overheating LFP batteries is usually divided into four stages,with high temperatures and fire risks.High-rate charge and discharge damage the internal morphology and structural stability of materials seriously.The TR behavior of battery is fully aggravated,which is further manifested by the advanced opening of the safety vent,release of gas and occurrence of TR.With the increase of charging rate,the deteriorated TR characteristics can be discerned,such as the lower TR temperature,the shorter TR time,and the more serious TR consequences.Such changes can be assigned to the decline of battery stability.In addition,the battery SOC greatly impacts safety,especially the flame temperature and the severity of consequences.As for the 100%SOC battery cycled at 4 C,there is still a high risk of thermal runaway propagation at the position 1 m far away from the battery.This work helps to realize the TR and fire features of battery in-depth,enlightening the safety protection of battery.展开更多
Needle-to-plane geometry has been widely investigated and used in underwater pulsed discharges.The position relationship between the needle tip and insulation layer significantly affects the discharge patterns.We carr...Needle-to-plane geometry has been widely investigated and used in underwater pulsed discharges.The position relationship between the needle tip and insulation layer significantly affects the discharge patterns.We carried out experiments on underwater pulsed discharge with the needle tip protruding from,recessing into,and flushing with the insulating tube.The results are as follows.First,underwater pulsed discharge has a strong randomness under the experimental conditions.Different discharge patterns appeared under the same experimental environment.Second,recession into the insulator surface led to a higher probability of occurrence but a lower strength of spark discharge than protrusion.Third,between the needle tip protruding from and recessing into the insulation material,the average speed of propagation of underwater pulsed spark discharge decreased by an order of magnitude.The study shows that the optimum length of needle tip protruding from the insulation layer is 1 mm to obtain a strong underwater pulsed spark discharge.展开更多
In this paper, volume barrier discharge with different gap distances is added on the discharge border of high-voltage electrode of annular surface barrier discharge for generating volume added surface barrier dischar...In this paper, volume barrier discharge with different gap distances is added on the discharge border of high-voltage electrode of annular surface barrier discharge for generating volume added surface barrier discharge （V-SBD） excited by bipolar nanosecond high-voltage pulse power in atmospheric air. The excited V-SBDs consist of surface barrier discharge （d = 0 mm） and volume added surface barrier discharges （d = 2 mm and 3 mm）. The optical emission spectra are recorded for calculating emission intensities of N2 （C3 ∏u → B3∏g） and N2＋ （B2 ∑u＋ → X2 ∑g＋）, and simulating rotational and vibrational temperatures. The influences of gap distance of V-SBD on emission intensity and plasma temperature are also investigated and analyzed. The results show that d = 0 mm structure can excite the largest emission intensity of N2 （C3 ∏u → B3 ∏g）, while the existence of volume barrier discharge can delay the occurrence of the peak value of the emission intensity ratio of N2 ＋ （B2 ∑u＋ → X2 ∑＋g）/N2 （C3 ∏u → B3 ∏g） during the rising period of the applied voltage pulse and weaken it during the end period. The increasing factor of emission intensity is effected by the pulse repetition rate. The d = 3 mm structure has the highest threshold voltage while it can maintain more emission intensity of N2 （C3 ∏u→ B3∏g） than that of d = 2 mm structure. The structure of d = 2 mm can maintain more increasing factor than that of the d = 3 mm structure with varying pulse repetition rate. Besides, the rotational temperatures of three V-SBD structures are slightly affected when the gap distance and pulse repetition rate vary. The vibrational temperatures have decaying tendencies of all three structures with the increasing pulse repetition rate.展开更多
Circle points discharge tube current controller is a new type device to limit the output of high voltage discharge current. Circle points uniform corona discharge to form air ionization current in the discharge tube. ...Circle points discharge tube current controller is a new type device to limit the output of high voltage discharge current. Circle points uniform corona discharge to form air ionization current in the discharge tube. On the outside, even if the discharge electrode is spark discharging or the two discharge electrodes are short circuited, the air ionization current in the tube remains within a stable range, and there is no spark discharge. In this case, when the discharge current only increases slightly, the requirement to limited current is obtained. By installing the controller at a discharge pole with a small power but high voltage supply, we can realize the shift between the continuous spark line discharge and corona discharge. This provides a new simple device for spark discharge research and is a supplement to the Townsend discharge experiment.展开更多
Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were...Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were depicted. Variations of the aforementioned four parameters are differently obvious. Ending criteria of charge and discharge of Ni/MH batteries are discussed on the basis of the curves. Voltage, capacity and temperature of a battery can be used as ending criteria during charge. When discharge takes place, voltage, capacity and internal resistance can be chosen as ending criteria. As a whole, capacity is more suitable for being used as ending criteria of charge and discharge than the other three parameters. At last, the capacity of a battery is recommended to be ending criteria of charge and discharge. The conclusions will provide references to different capacity Ni/MH batteries for electric vehicles.展开更多
The influences of intense magnetic pinch effect caused by electromagnetic field with high frequency on discharge channel expansion and plasma configuration change are discussed. The change of Lorentz force exerting on...The influences of intense magnetic pinch effect caused by electromagnetic field with high frequency on discharge channel expansion and plasma configuration change are discussed. The change of Lorentz force exerting on charged particles in discharge channel is calculated under the electromagnetic field with high frequency. Through the theoretical analysis and experimental study, the forming process of discharge channel is conjectured. And it is considered that the changes of discharge channel, such as the decrease of diameter and increase of energy density, coming from the intense magnetic pinch effect in high frequency electromagnetic field, are the main reasons for a series of special phenomena on the machined surface in micro EDM.展开更多
基金supported by National Key Research and Development Program of China(2022YFB3804902,2022YFB3804900)the National Natural Science Foundation of China(52203226,52161145406,42376045)the Fundamental Research Funds for the Central Universities(2232024Y-01,2232025D-02).
文摘While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.
基金supported by the Natural Science Foundation of Inner Mongolia Autonomous Region of China(No.2023QN04011)the National Natural Science Foundation of China(Nos.42307092 and 52279067)+1 种基金Ordos Science and Technology Major Project(No.ZD20232303)Project of Key Laboratory of River and Lake in Inner Mongolia Autonomous Region(No.2022QZBZ0003).
文摘Lacustrine groundwater discharge(LGD)plays an important role in water resources management.Previous studies have focused on LGD process in a single lake,but the differences in LGD process within the same region have not been thoroughly investigated.In this study,multiple tracers(hydrochemistry,𝛿D,𝛿18O and 222Rn)were used to compare mechanisms of LGD in Daihai and Ulansuhai Lake in Inner Mongoli1,Northwest China.The hydrochemical types showed a trend from groundwater to lake water,indicating a hydraulic connection between them.In addition,the𝛿D and𝛿18O values of sediment pore water were between the groundwater and lake water,indicating the LGD processes.The radon mass balance model was used to estimate the average groundwater discharge rates of Daihai and Ulansuhai Lake,which were 2.79 mm/day and 3.02 mm/day,respectively.The total nitrogen(TN),total phosphorus(TP),and fluoride inputs associated with LGD in Daihai Lake accounted for 97.52%,96.59%,and 95.84%of the total inputs,respectively.In contrast,TN,TP and fluoride inputs in Ulansuhai Lake were 53.56%,40.98%,and 36.25%,respectively.This indicates that the pollutant inputs associated with LGD posed a potential threat to the ecological stability of Daihai and Ulansuhai Lake.By comparison,the differences of LGD process and associated pollutant flux were controlled by hydrogeological conditions,lakebed permeability and human activities.This study provides a reference for water resources management in Daihai and Ulansuhai Lake basins while improving the understanding of LGD in the Yellow River basin.
基金Project supported by the National Natural Science Foundation of China (Grant No. 52377135)。
文摘Based on a homemade novel dielectric barrier discharge actuator with a rotating high-voltage electrode, this study investigates the influence of electrode rotating speed on the discharge characteristics, and the mechanisms of discharge process under rotary conditions are discussed. The results demonstrate that when the high-voltage electrode is rotating,the distribution patterns of dielectric barrier discharge and the parameters of micro-discharge channels exhibit significant changes. Under a low rotating speed, the discharge patterns present as a series of separated discharge channels, resulting in uniform charge distribution but uneven electric field distribution in the gap. As the rotating speed increases, the electric field and the discharge channels will be affected by the rotation, so the electric field is more evenly distributed in the gap, and the discharge mode changes to a quasi-uniform discharge. With increasing distance from the rotation axis, the electric field strength gradually decreases, and the electric field force experienced by the micro-discharge channels during its formation weakens. Consequently, the average size of the micro-discharge channels increases, indicating that these channels are gradually stretched. The rotation of the electrode generates a significant number of accumulated charges, impacting the number of micro-discharge channels. The number of micro-discharge channels at the center of the electrode increases with rotating speed;however, due to channel stretching, the average size of the micro-discharge channels at the edge of the electrode also increases, leading to a decrease in their overall quantity. The research results reveal the significant impact of the electrode rotation on the characteristics of discharge channels, providing a theoretical basis for further optimal design of the rotating dielectric barrier discharge in various application.
基金supported by Postgraduate Research&Practice Innovation Program of Jiangsu Province (No. 1003016001)。
文摘Flexible surface micro-discharge plasma is a non-thermal plasma technique used for treating wounds in a painless way, with significant efficacy for chronic or hard-to-heal wounds. In this study, a confined space was designed to simulate wound conditions, with gelatin used to simulate wound tissue. The distinction between open and confined spaces was explored, and the effects of temperature, humidity, discharge power and the gap size within the confined space on the plasma characteristics were analyzed. It was found that temperature, humidity and discharge power are important factors that affect the concentration distribution of active components and the mode transition between ozone and nitrogen oxides. Compared to open space, the concentration of ozone in confined space was relatively lower, which facilitated the formation of nitrogen oxides. In open space, the discharge was dominated by ozone initially. As the temperature,humidity and discharge power increased, nitrogen oxides in the gas-phase products were gradually detected. In confined space, nitrogen oxides can be detected at an early stage and at much higher concentrations than ozone concentration. Furthermore, as the gap of the confined space decreased, the concentration of ozone was observed to decrease while that of nitrate increased, and the rate of this concentration change was further accelerated at higher temperature and higher power. It was shown that ozone concentration decreased from 0.11 to 0.03 μmol and the nitrate concentration increased from 20.5 to 24.5 μmol when the spacing in the confined space was reduced from 5 to 1 mm, the temperature of the external discharge was controlled at 40 ℃, and the discharge power was 12 W. In summary, this study reveals the formation and transformation mechanisms of active substances in air surface micro-discharge plasma within confined space, providing foundational data for its medical applications.
基金supported by the National Natural Science Foundation of China(52471095)National Key Research and Development Program of China(Grant No.2023YFC2811404)Natural Science Foundation of Xiamen,China(No.3502Z20227015)。
文摘This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca(AZ63X)anode for Mg-air battery.An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but does not hinder the transfer of the electrons at the interface.Fortunately,the addition of Ce,La,and Ca into AZ63 alloy achieves this goal.The Mg-air battery with AZ63X anode in 3.5%Na Cl has an ultrahigh anodic efficiency of 85.7±1.7%and energy-density of 2431±53 mWh g^(-1)with the unique discharge product film,surpassing the values of most reported Mg-air batteries.Furthermore,the alloying elements reduce the anode delamination effect significantly by transforming the block Mg_(17)Al_(12)phase into the connected Mg_(17)Al_(12)structure and fine rod Al_(2)RE and Al_(2)Ca.
基金The National Natural Science Foundation of China(No.51976039)。
文摘To explore the electrostatic discharge behavior of charged powders in industrial silos,discharge experiments are conducted based on a full-size industrial silo discharge platform.Electrostatic discharge mode,frequency,and energy are investigated for powders of different polarities.Although the powders have low charge-to-mass ratios(+0.087μC/kg for the positively charged powders and−0.26μC/kg for the negatively charged ones),electrostatic discharges occur approximately every 10 s,with the maximum discharge energy being 800 mJ.Powder polarity considerably influences discharge energy.The positive powders exhibit higher discharge energy than the negative ones,although discharge frequency remains similar for both.Effects of powder charge,humidity,and mass flow on discharge frequency and discharge energy are quantitatively analyzed,providing important insights for the improvement of safety in industrial powder handling.
基金Construction and Practice of a discharge Preparation Plan for First-visit Ischemic stroke patients Based on the ADOPT model(Project No.:XJ2023005101)。
文摘Objective:To investigate the application effect of the discharge preparation plan based on the ADOPT nursing model in patients with first-visit ischemic stroke.Methods:Eighty patients with first-visit ischemic stroke admitted to our hospital from June 1,2024 to November 31,2024 were selected and divided into a control group(June 1,2024 to August 30,2024)and an intervention group(September 1,2024 to November 31,2024)according to different admission times,with 40 cases in each group.The control group received routine care and discharge guidance,while the intervention group received a discharge preparation plan based on the ADOPT model on the basis of routine care.The discharge readiness[Discharge Readiness Scale(RHDS)]of patients on the day of discharge was compared.Self-efficacy at 3 months after discharge[evaluated using the Chronic Disease Self-Efficacy Scale(SECD6)],activities of daily living[evaluated using the Barthel index(BI)],blood glucose and blood pressure indicators(diastolic blood pressure,systolic blood pressure,FPG,2 h PG),and readmission rate within 3 months after discharge were also compared between the two groups.Results:On the day of discharge,the RHDS-related dimension scores of the intervention group were higher than those of the control group(t=17.993,8.560,10.243,p<0.05);Three months after discharge,the SECD6 score and BI score of the intervention group were higher than those of the control group(t=8.910,10.899,both p<0.05);Systolic blood pressure,diastolic blood pressure,FPG and 2h PG in the intervention group were lower than those in the control group(t=8.868,4.794,3.829,7.121,all p<0.05);Within 3 months after discharge,the readmission rate of the intervention group was lower than that of the control group(χ^(2)=5.165,2 p<0.05).Conclusion:The discharge preparation plan based on the ADOPT nursing model,when applied to patients with first-visit ischemic stroke,can not only enhance self-efficacy and discharge preparation,improve activities of daily living,but also optimize blood glucose and blood pressure indicators and reduce the readmission rate,which is worthy of reference.
基金National Key R&D Program of China(No.2020YFC2201000).
文摘Research has been carried out on a hybrid discharge ion thruster,aiming to combine the advantages of Direct Current(DC)discharge ion thrusters(known for their high thrust density and high power supply efficiency)with microwave discharge ion thrusters(which do not require a hollow cathode and are capable of efficient ionization at low pressures).Comparative experiments with different anode structures and single-probe diagnostics revealed that applying a DC bias voltage created a new ionization zone based on microwave discharge.This DC bias increased the sheath potential of the screen grid and led to an elevation in electron temperature and plasma density.It is speculated that the reduced loss of high-energy electrons generated by microwave discharge at the screen grid is the primary reason for the enhanced discharge.By adding a DC bias of approximately 50 V to the microwave discharge,the screen grid current was doubled without a significant increase in discharge power consumption.Under appropriate bias voltages that consider minimizing ion sputtering,DC bias holds promise as a design approach to increase the extracted beam current in microwave ion thrusters.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12375250,11875121,51977057,11805013)the Natural Science Foundation of Hebei Province,China(Grant Nos.A2020201025 and A2022201036)+3 种基金the Hebei Province Optoelectronic Information Materials Laboratory Performance Subsidy Fund Project(Grant No.22567634H)the Funds for Distinguished Young Scientists of Hebei Province,China(Grant No.A2012201045)the Natural Science Interdisciplinary Research Program of Hebei University(Grant Nos.DXK201908 and DXK202011)the Post-graduate’s Innovation Fund Project of Hebei University(Grant No.HBU2022bs004)。
文摘As a popular approach to producing atmospheric pressure non-thermal plasma,dielectric barrier discharge(DBD)has been extensively used in various application fields.In this paper,DBD with wavy dielectric layers is numerically simulated in atmospheric pressure helium mixed with trace nitrogen based on a fluid model.With varying relative position(phase difference(Δφ))of the wavy surfaces,there is a positive discharge and a negative discharge per voltage cycle,each of which consists of a pulse stage and a hump stage.For the pulse stage,maximal current increases with increasingΔφ.Results show that DBD with the wavy surfaces appears as discrete micro-discharges(MDs),which are self-organized to different patterns with varyingΔφ.The MDs are vertical and uniformly-spaced withΔφ=0,which are self-organized in pairs withΔφ=π/4.These MD pairs are merged into some bright wide MDs withΔφ=π/2.In addition,narrow MDs appear between tilted wide MDs withΔφ=3π/4.WithΔφ=π,the pattern is composed of wide and narrow MDs,which are vertical and appear alternately.To elucidate the formation mechanism of the patterns with differentΔφ,temporal evolutions of electron density and electric field are investigated for the positive discharge.Moreover,surface charge on the wavy dielectric layers has also been compared with differentΔφ.
基金supported by National Natural Science Foundation of China(Nos.11875121,51977057,11575050,11875014)the Hebei Province Natural Science Foundation(No.A2022201036)。
文摘This paper describes the realization of a homogeneous dielectric barrier discharge(DBD)in argon at atmospheric pressure.The effect of the morphology of the dielectric surface(especially the dielectric surface covered by hollow ceramic beads(99%Al_(2)O_(3))with different diameters)on discharge is investigated.With different dielectrics,the argon DBD presents two discharge modes:a filamentary mode and a homogeneous mode.Fast photography shows that the filamentary mode operates in a streamer discharge,and the homogeneous mode operates in a Townsend discharge regime.It is found that a homogeneous discharge can be generated within a certain voltage range.The voltage amplitude range decreases,and the breakdown voltage increases with the increase in the mean diameter of the ceramic beads.Waveforms of the total current and optical emission signal present stochastic pulses per half voltage cycle for the filamentary mode,whereas there is one single hump per half voltage cycle for the homogeneous mode.In the homogeneous mode,the intensity of the optical emission decreases with the mean diameter of the ceramic beads.The optical emission spectrum is mainly composed of atomic lines of argon and the second positive system of molecular nitrogen.It reveals that the electron density decreases with the increasing mean diameter of the ceramic beads.The vibrational temperature increases with the increasing mean diameter of the ceramic beads.It is believed that a large number of microdischarges are formed,and smaller ceramic beads have a larger activation surface area and more point discharge.Electrons liberated in the shallow well and electrons generated from microdischarges can increase the secondary electron emission coefficient of the cathode and provide initial electrons for discharge continuously.Therefore,the breakdown electric field is reduced,which contributes to easier generation of homogeneous discharge.This is confirmed by the simulation results.
基金partially supported by the National Natural Science Foundation of China(No.51901153)Shanxi Scholarship Council of China(No.2019032)+1 种基金the Natural Science Foundation of Shanxi,China(No.202103021224049)the Shanxi Zhejiang University New Materials and Chemical Research Institute Scientific Research Project,China(No.2022SX-TD025)。
文摘A novel precipitate-free Mg-0.1Sn anode with a homogeneous equal-axis grain structure was developed and rolled successfully at 573 K.Electrochemical test results indicate that the Mg-0.1Sn alloy exhibits enhanced anode dissolution kinetics.A Mg-air battery prepared using this anode exhibits a cell voltage of 1.626 V at 0.5 mA/cm^(2),reasonable anodic efficiency of 58.17%,and good specific energy of 1730.96 mW·h/g at 10 mA/cm^(2).This performance is attributed to the effective reactive anode surface,the suppressed chunk effect,and weak self-corrosion owing to the homogeneous basal texture.
文摘With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater\|discharge coefficient, complete wastewater\|discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in Beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFD1700802).
文摘To enhance the operational capacity and space utilization of baffle-drop shafts,this study improved the traditional baffle-drop shaft by expanding the wet-side space,incorporating large rotation-angle baffles,and installing overflow holes in the dividing wall.A three-dimensional turbulent model was developed using ANSYS Fluent to simulate the hydraulic characteristics of both traditional and new baffle-drop shafts across various flow rates.The simulation results demonstrated that the new shaft design allowed for discharge from both the wet and dry sides,significantly improving operational capacity,with the dry side capable of handling 40%of the inlet flow.Compared to the traditional shaft,the new design reduced shaft wall pressures and decreased the mean and standard deviation of pressure on typical baffles by 21%and 63%,respectively,therefore enhancing structural safety.Additionally,the new shaft achieved a 2%-12%higher energy dissipation rate than the traditional shaft across different flow rates.This study offers valuable insights for the design and optimization of drop shafts in deep tunnel drainage systems.
基金supported by National Natural Science Foundation of China(No.U23B20152).
文摘The deposition layer on the discharge channel wall of a Hall thruster after long-term operation occasionally detaches from the wall and interferes with the plasma inside the channel,resulting in current pulse and threatening the power supply.To understand the generation mechanism of the current pulse,the interaction between the peeling material and the channel plasma was studied by the particle-in-cell and Monte Carlo collision(PIC/MCC)method.The plasma evolution and distribution in the Hall thruster channel when peeling material existed were simulated.Simulation results show that the peeling material changes the electron transportation and ionization,and the effects are related to the position of the peeling material.When the peeling material invades the zone where the ionization rate is originally the highest without peeling material,the ionization process is almost terminated.The ionization suppression by the peeling material will cause the propellant gas to refill the channel exit.As the peeling material moves away,gas discharge is induced near the channel exit,resulting in anode current pulse.
基金supported by the National Key Research and Development Plan(2023YFC3009900)the National Natural Science Foundation of China(52104197,52272396,52474233)+3 种基金Hongkong Scholar Program(XJ2022022)Research Grants Council of the Hong Kong Special Administrative Region(City U11214221)Natural Science Foundation of the Jiangsu Higher Education Institutions(21KJB620001)the Open Fund of the State Key Laboratory of Fire Science(SKLFS)Program(HZ2022-KF04)。
文摘In this work,a series of experiments are carried out to investigate the effect of charge/discharge rates(1,2,3 and 4 C)and state of charges(SOCs,namely 0%,50%,75%and 100%)on thermal runaway(TR)and fire behavior of lithium iron phosphate(LFP)batteries.The TR process caused by overheating LFP batteries is usually divided into four stages,with high temperatures and fire risks.High-rate charge and discharge damage the internal morphology and structural stability of materials seriously.The TR behavior of battery is fully aggravated,which is further manifested by the advanced opening of the safety vent,release of gas and occurrence of TR.With the increase of charging rate,the deteriorated TR characteristics can be discerned,such as the lower TR temperature,the shorter TR time,and the more serious TR consequences.Such changes can be assigned to the decline of battery stability.In addition,the battery SOC greatly impacts safety,especially the flame temperature and the severity of consequences.As for the 100%SOC battery cycled at 4 C,there is still a high risk of thermal runaway propagation at the position 1 m far away from the battery.This work helps to realize the TR and fire features of battery in-depth,enlightening the safety protection of battery.
基金supported by the Science and Technology Research Project of the Hebei Higher Education Institutions of China No.ZD2014031。
文摘Needle-to-plane geometry has been widely investigated and used in underwater pulsed discharges.The position relationship between the needle tip and insulation layer significantly affects the discharge patterns.We carried out experiments on underwater pulsed discharge with the needle tip protruding from,recessing into,and flushing with the insulating tube.The results are as follows.First,underwater pulsed discharge has a strong randomness under the experimental conditions.Different discharge patterns appeared under the same experimental environment.Second,recession into the insulator surface led to a higher probability of occurrence but a lower strength of spark discharge than protrusion.Third,between the needle tip protruding from and recessing into the insulation material,the average speed of propagation of underwater pulsed spark discharge decreased by an order of magnitude.The study shows that the optimum length of needle tip protruding from the insulation layer is 1 mm to obtain a strong underwater pulsed spark discharge.
基金supported by National Key R&D Program of China (2016YFC0207200)National Natural Science Foundation of China (Nos. 51377014, 51407022 and 51677019)
文摘In this paper, volume barrier discharge with different gap distances is added on the discharge border of high-voltage electrode of annular surface barrier discharge for generating volume added surface barrier discharge （V-SBD） excited by bipolar nanosecond high-voltage pulse power in atmospheric air. The excited V-SBDs consist of surface barrier discharge （d = 0 mm） and volume added surface barrier discharges （d = 2 mm and 3 mm）. The optical emission spectra are recorded for calculating emission intensities of N2 （C3 ∏u → B3∏g） and N2＋ （B2 ∑u＋ → X2 ∑g＋）, and simulating rotational and vibrational temperatures. The influences of gap distance of V-SBD on emission intensity and plasma temperature are also investigated and analyzed. The results show that d = 0 mm structure can excite the largest emission intensity of N2 （C3 ∏u → B3 ∏g）, while the existence of volume barrier discharge can delay the occurrence of the peak value of the emission intensity ratio of N2 ＋ （B2 ∑u＋ → X2 ∑＋g）/N2 （C3 ∏u → B3 ∏g） during the rising period of the applied voltage pulse and weaken it during the end period. The increasing factor of emission intensity is effected by the pulse repetition rate. The d = 3 mm structure has the highest threshold voltage while it can maintain more emission intensity of N2 （C3 ∏u→ B3∏g） than that of d = 2 mm structure. The structure of d = 2 mm can maintain more increasing factor than that of the d = 3 mm structure with varying pulse repetition rate. Besides, the rotational temperatures of three V-SBD structures are slightly affected when the gap distance and pulse repetition rate vary. The vibrational temperatures have decaying tendencies of all three structures with the increasing pulse repetition rate.
文摘Circle points discharge tube current controller is a new type device to limit the output of high voltage discharge current. Circle points uniform corona discharge to form air ionization current in the discharge tube. On the outside, even if the discharge electrode is spark discharging or the two discharge electrodes are short circuited, the air ionization current in the tube remains within a stable range, and there is no spark discharge. In this case, when the discharge current only increases slightly, the requirement to limited current is obtained. By installing the controller at a discharge pole with a small power but high voltage supply, we can realize the shift between the continuous spark line discharge and corona discharge. This provides a new simple device for spark discharge research and is a supplement to the Townsend discharge experiment.
文摘Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were depicted. Variations of the aforementioned four parameters are differently obvious. Ending criteria of charge and discharge of Ni/MH batteries are discussed on the basis of the curves. Voltage, capacity and temperature of a battery can be used as ending criteria during charge. When discharge takes place, voltage, capacity and internal resistance can be chosen as ending criteria. As a whole, capacity is more suitable for being used as ending criteria of charge and discharge than the other three parameters. At last, the capacity of a battery is recommended to be ending criteria of charge and discharge. The conclusions will provide references to different capacity Ni/MH batteries for electric vehicles.
基金Supported by the National Natural Science Foundation of China(50635040)~~
文摘The influences of intense magnetic pinch effect caused by electromagnetic field with high frequency on discharge channel expansion and plasma configuration change are discussed. The change of Lorentz force exerting on charged particles in discharge channel is calculated under the electromagnetic field with high frequency. Through the theoretical analysis and experimental study, the forming process of discharge channel is conjectured. And it is considered that the changes of discharge channel, such as the decrease of diameter and increase of energy density, coming from the intense magnetic pinch effect in high frequency electromagnetic field, are the main reasons for a series of special phenomena on the machined surface in micro EDM.
