This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by...This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by means of a fluid–structure interaction(FSI)method by which the descaling effect produced by rolling coils with different section sizes is examined.Assuming a flat fan-shaped nozzle at the entrance of the R1R2 roughing mill,the outflow field characteristics and the velocity distribution curve on the strike line(at a target distance of 30–120 mm)are determined.It is found that the velocity in the center region of the water jet with different target distances is higher than that in the boundary region.As the target distance increases,the velocity of the water jet in the central region decreases.Through comparison with experimental results,it is shown that the simulation model can accurately predict the impact position of the high-pressure water on the impact plate,thereby providing a computational scheme that can be used to optimize the nozzle space layout and improve the slabs’descent effect for different rolling specifications.展开更多
The hydrogen-iron(HyFe)flow cell has great potential for long-duration energy storage by capitalizing on the advantages of both electrolyzers and flow batteries.However,its operation at high current density(high power...The hydrogen-iron(HyFe)flow cell has great potential for long-duration energy storage by capitalizing on the advantages of both electrolyzers and flow batteries.However,its operation at high current density(high power)and over continuous cycling testing has yet to be demonstrated.In this paper,we discuss our design and demonstration of a water management strategy that supports high current and long cycling performance of a HyFe flow cell.Water molecules associated with the movement of protons from the iron electrode to the hydrogen electrode are sufficient to hydrate the membrane and electrode at a low current density of 100 mA cm^(-2)during the charge process.At higher charge current density,more aggressive measures must be taken to counter back-diffusion driven by the acid concentration gradient between the iron and hydrogen electrodes.Our water management approach is based on water vapor feeding in the hydrogen electrode,and water evaporation in the iron electrode,thus enabling the high current density operation of 300 mA cm^(-2).展开更多
Zinc-based flow batteries(ZFBs)have aroused great favor in large-scale energy storage due to the high security and low cost.However,the low areal capacity arising from the limited space for Zn plating hinders the furt...Zinc-based flow batteries(ZFBs)have aroused great favor in large-scale energy storage due to the high security and low cost.However,the low areal capacity arising from the limited space for Zn plating hinders the further development.Herein,a novel carbon felt-Sn-carbon felt sandwich host(CSCH)is designed and constructed.Benefiting from the strong chemical absorption and the dehydration effect on Zn(H_(2)O)_(6)^(2+),the Sn activation layer in the CSCH demonstrates the lowest comprehensive resistance for Zn deposition.Thus,Zn is induced to nucleate preferentially on the Sn activation layer,and grows towards the membrane,regulating the spatial distribution of Zn electrochemical deposits,which remarkably improves the areal capacity and cyclic stability of Zn anode.Consequently,the zinc-bromine flow batteries equipped with CSCH electrodes can achieve the ultra-high areal capacity of 120 mA h cm^(-2)at 80 mA cm^(-2),and run stably for 140 h with average energy efficiency of 80.3%in the extreme condition(80 mA cm^(-2),80 mA h cm^(-2)).This innovative work will inspire future advanced designs for high areal capacity electrodes in ZFBs.展开更多
BACKGROUND High flow priapism(HFP)is a rare type of priapism.Perineal trauma is the most common cause of HFP.Trauma-induced penile artery injury may lead to an arterial-cavernosal fistula,whereas persistent irregular ...BACKGROUND High flow priapism(HFP)is a rare type of priapism.Perineal trauma is the most common cause of HFP.Trauma-induced penile artery injury may lead to an arterial-cavernosal fistula,whereas persistent irregular arterial blood flow entering the corpora cavernosum can cause a persistent penile erection.The routine treatment of HFP focuses on addressing the abnormal penile erectile status and avoiding post-treatment erectile dysfunction.Interventional embolization is an important therapeutic modality for HFP,and bilateral embolization therapy is currently the most commonly used technique for patients with bilateral cavernous artery fistulas;however,unilateral embolization therapy has yet to be reported.CASE SUMMARY Herein,we report of the case of a 26-year-old Chinese male who presented with a persistent abnormal erection for 12 h after perineal impact injury.Medical history,cavernous arterial blood gas analysis and radiological examinations led to a diagnosis of HFP caused by bilateral cavernous artery fistulas.We performed routine conservative treatment(compression therapy and ice application)for the patient after admission;however,10 d later,his symptoms had not been relieved.After completion of the preoperative workup,right(severe side)selective perineal artery embolization was performed;the left cavernous artery fistula was left untreated.After postoperative continuation of conservative treatment for 72 h,the patient experienced complete penile thinning.The patient had no symptoms of erectile dysfunction over a follow-up period of 12 mo.CONCLUSION Compared with bilateral cavernous artery fistula embolization,we believe that unilateral cavernous artery fistula embolization can achieve positive clinical efficacy and reduce the risk of postoperative erectile dysfunction secondary to penile ischemia.展开更多
Arteriovenous fistulas have a substantial impact on systemic hemodynamics, however their effect on extracorporeal circulation is not well understood. We report our clinical observation on the management under extracor...Arteriovenous fistulas have a substantial impact on systemic hemodynamics, however their effect on extracorporeal circulation is not well understood. We report our clinical observation on the management under extracorporeal circulation of a patient with renal insufficiency with a high-flow arteriovenous fistula. This is a 59-year-old man who was referred to us for surgical treatment of ischemic coronary artery disease in a context of anuric chronic renal failure. Hypothermia at 32°C is started from the start in CEC due to hyperflow at the level of the arteriovenous fistula. We performed two coronary artery bypasses of the marginal and IVA via the two internal thoracic arteries. The patient is hemofiltered in order to avoid hyperkalaemia and possibly avoid fluid overload related to filling per CEC. The clamping time was 71 minutes and the SCC lasted 141 minutes. There was no homologous transfusion in the operating room. It turns out that the input/output balance is zero at the end of the CEC. The postoperative course was simple.展开更多
The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 hor...The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.展开更多
In order to improve the reliability of the spacecraft micro cold gas propulsion system and realize the precise control of the spacecraft attitude and orbit, a micro-thrust, high-precision cold gas thruster is carried ...In order to improve the reliability of the spacecraft micro cold gas propulsion system and realize the precise control of the spacecraft attitude and orbit, a micro-thrust, high-precision cold gas thruster is carried out, at the same time due to the design requirements of the spacecraft, this micro-thrust should be continuous working more than 60 minutes, the traditional solenoid valve used for the thrusts can’t complete the mission, so a long-life micro latching valve is developed as the control valve for this micro thruster, because the micro latching valve can keep its position when it cuts off the outage. Firstly, the authors introduced the design scheme and idea of the thruster. Secondly, the performance of the latching valve and the flow characteristics of the nozzle were simulated. Finally, from the experimental results and compared with the numerical study, it shows that the long-life micro cold gas thruster developed in this paper meets the mission requirements.展开更多
The experimental investigation of axial-flow pump has been rapidly developed to meet the needs of South-to-North Water Diversion Project of China. Owing to the boundary conditions of hub, blade tip clearance, much of ...The experimental investigation of axial-flow pump has been rapidly developed to meet the needs of South-to-North Water Diversion Project of China. Owing to the boundary conditions of hub, blade tip clearance, much of the physical phenomena and laws involved in this complex flow field can't be fully determined. The flow characteristics of the high efficiency axial-flow pump have been simulated by RNG k-e turbulence model and SIMPLEC arithmetic based on FLUENT software. Numerical results indicate that the data from the prediction show agreement with the experimental results, static pressure on pressure side of blades increases slightly at circumferential direction with radius increasing, and keep almost constant at the same radial while increasing gradually from inlet to exit on the suction side along flow direction at design conditions. The static pressure, total pressure and velocity at inlet, impeller outlet and vane outlet were measured by a five-hole probe, and a contrastive experiment was done to investigate the influence of hub leakage. The experimental results show that inlet flow is almost axial and the prerotation is very small at various conditions. The meridional velocity and circulation distribution are almost identical at impeller outlet at design conditions due to steady flow and high efficiency. The residual circulation exits at downstream of the guide vane, and the circumferential velocity component increases linearly from hub to tip at small flow rate conditions. Hub leakage in adjustable blades results in the decrease of the meridional velocity and circulation at blade exit near hub. The results of numerical simulation and experiments supply important flow structure information for the high-efficiency axial-flow pump.展开更多
The studies of asymmetric vortices flow over slender body and its active control at high angles of attack have significant importance for both academic field and engineering area.This paper attempts to provide an upda...The studies of asymmetric vortices flow over slender body and its active control at high angles of attack have significant importance for both academic field and engineering area.This paper attempts to provide an update state of art to the investigations on the fields of forebody asymmetric vortices.This review emphasizes the correlation between micro-perturbation on the model nose and its response and evolution behaviors of the asymmetric vortices.The critical issues are discussed, which include the formation and evolution mechanism of asymmetric multi-vortices;main behaviors of asymmetric vortices flow including its deterministic feature and vortices flow structure;the evolution and development of asymmetric vortices under the perturbation on the model nose;forebody vortex active control especially discussed micro-perturbation active control concept and technique in more detail.However present understanding in this area is still very limited and this paper tries to identify the key unknown problems in the concluding remarks.展开更多
The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by...The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and experiment.Falling film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film thickness.The comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good agreement.The simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental results.This work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.展开更多
In order to describe an investigation of the flow around high-speed train on a bridge under cross winds using detached-eddy simulation(DES), a 1/8th scale model of a three-car high-speed train and a typical bridge mod...In order to describe an investigation of the flow around high-speed train on a bridge under cross winds using detached-eddy simulation(DES), a 1/8th scale model of a three-car high-speed train and a typical bridge model are employed, Numerical wind tunnel technology based on computational fluid dynamics(CFD) is used, and the CFD models are set as stationary models. The Reynolds number of the flow, based on the inflow velocity and the height of the vehicle, is 1.9×10~6. The computations are conducted under three cases, train on the windward track on the bridge(WWC), train on the leeward track on the bridge(LWC) and train on the flat ground(FGC). Commercial software FLUENT is used and the mesh sensitivity research is carried out by three different grids: coarse, medium and fine. Results show that compared with FGC case, the side force coefficients of the head cars for the WWC and LWC cases increases by 14% and 29%, respectively; the coefficients of middle cars for the WWC and LWC increase by 32% and 10%, respectively; and that of the tail car increases by 45% for the WWC whereas decreases by 2% for the LWC case. The most notable thing is that the side force and the rolling moment of the head car are greater for the LWC, while the side force and the rolling moment of the middle car and the tail car are greater for the WWC. Comparing the velocity profiles at different locations, the flow is significantly influenced by the bridge-train system when the air is close to it. For the three cases(WWC, LWC and FGC), the pressure on the windward side of train is mostly positive while that of the leeward side is negative. The discrepancy of train's aerodynamic force is due to the different surface area of positive pressure and negative pressure zone. Many vortices are born on the leeward edge of the roofs. Theses vortices develop downstream, detach and dissipate into the wake region. The eddies develop irregularly, leading to a noticeably turbulent flow at leeward side of train.展开更多
By coupling the non-equilibrium extrapolation scheme for boundary condition with the multi-relaxation-time lattice Boltzmann method, this paper finds that the stability of the multi-relaxation-time model can be improv...By coupling the non-equilibrium extrapolation scheme for boundary condition with the multi-relaxation-time lattice Boltzmann method, this paper finds that the stability of the multi-relaxation-time model can be improved greatly, especially on simulating high Reynolds number (Re) flow. As a discovery, the super-stability analysed by Lallemand and Luo is verified and the complex structure of the cavity flow is also exhibited in our numerical simulation when Re is high enough. To the best knowledge of the authors, the maximum of Re which has been investigated by direct numerical simulation is only around 50 000 in the literature; however, this paper can readily extend the maximum to 1000 000 with the above combination.展开更多
A protic ionic liquid is designed and implemented for the first time as a solvent for a high energy density vanadium redox flow battery.Despite being less conductive than standa rd aqueous electrolytes,it is thermally...A protic ionic liquid is designed and implemented for the first time as a solvent for a high energy density vanadium redox flow battery.Despite being less conductive than standa rd aqueous electrolytes,it is thermally stable on a 100 ℃ temperature window,chemically stable for at least 60 days,equally viscous and dense with typical aqueous solvents and most importantly able to solubilize to 6 mol L^(-1) vanadium sulfate,thus increasing the VRFB energy density by a factor of 2.5.Electrochemical measurements revealed quasi-reversible redox transitions for both catholyte and anolyte at 25 ℃ while a proof-of-concept redox flow cell with the proposed electrolyte was tested for a total of 150 cycles at 25 ℃,showing an open circuit potential of 1.39 V and energy and coulombic efficiencies of 65% and 93%,respectively.What’s more,the battery can be equally cycled at 45℃ showing good thermal stability.This study underlines a new route to improve the energy-to-volume ratio of energy storage system.展开更多
High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate a...High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously.A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system.A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design.Mathematical models of the opening process and flow rate of the valve are established.Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response.Corresponding formulas to solve 4 parts of the response time are derived.Key factors that influence the opening response time are analyzed.According to the mathematical model of the valve,a simulation of the opening process is carried out by MATLAB.Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve.Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool.The experimental results are in agreement with the simulated results,therefore the validity of the theoretical analysis is verified.Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa.The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s.According to the result of the load driving test,the valve can meet the demands of the driving system.The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.展开更多
A new method for the determination of trace non-rare earth elements in high purity rare earth oxides by ICP-AES with preconcentration on an active carbon-silica gel microcolumn in a flow injection system is described ...A new method for the determination of trace non-rare earth elements in high purity rare earth oxides by ICP-AES with preconcentration on an active carbon-silica gel microcolumn in a flow injection system is described in this paper. Experimental parameters such as pH, flow rate,reagent concentration,length of reaction coil,eluent acidity,etc. were optimized. In the buffer solution of NH3. H2O/NH4Cl at pH 4. 6,Al,Cr,Cu,Fe, Pb, V and Zn can be preconcentrated and then eluted with 4. 5 mol/L nitric acid utilizing stop-flow technique. The enrichment factors were in range of 8. 1 ̄12. 6 with detection limits of μg/m level ,and the RSD with metals at μg/g level were 2. 3 ̄5. 0% (n= 7). The method proposed can reduce the matrix interference effectively , and has been applied to the determination of non-rare earth metals atμg/g level in high purity Eu2O3 with satisfactory results.展开更多
On the basis of the data obtained on Gleeble 1500 Thermal Simulator, the predicting models for the relation between stable flow stress during high temperature plastic deformation and deformation strain, strain rate an...On the basis of the data obtained on Gleeble 1500 Thermal Simulator, the predicting models for the relation between stable flow stress during high temperature plastic deformation and deformation strain, strain rate and temperature for 1420 Al Li alloy have been developed with BP artificial neural networks method. The results show that the model on basis of BPNN is practical and it reflects the actual feature of the deforming process. It states that the difference between the actual value and the output of the model is in order of 5%. [展开更多
BACKGROUND Hypoxemia is a common complication in older patients during postoperative recovery and can cause pulmonary complications.Therefore,reducing the incidence of postoperative hypoxemia is a clinical concern.AIM...BACKGROUND Hypoxemia is a common complication in older patients during postoperative recovery and can cause pulmonary complications.Therefore,reducing the incidence of postoperative hypoxemia is a clinical concern.AIM To investigate the clinical efficacy of high-flow nasal cannula oxygen(HFNCO)in the resuscitation period of older orthopedic patients.METHODS In this prospective randomized controlled trial,60 older patients who underwent orthopedic surgery under general anesthesia were randomly divided into two groups:those who used conventional face mask and those who used HFNCO.All patients were treated with 60%oxygen for 1 h after extubation.Patients in the conventional face mask group were treated with a combination of air(2 L)and oxygen(2 L)using a traditional mask,whereas those in the HFNCO group were treated with HFNCO at a constant temperature of 34℃ and flow rate of 40 L/min.We assessed the effectiveness of oxygen therapy by monitoring the patients’arterial blood gas,peripheral oxygen saturation,and postoperative complications.RESULTS The characteristics of the patients were comparable between the groups.One hour after extubation,patients in HFNCO group had a significantly higher arterial partial pressure of oxygen(paO_(2))than that of patients in conventional face mask group(P<0.001).At extubation and 1 h after extubation,patients in both groups showed a significantly higher arterial partial pressure of carbon dioxide(paCO_(2))than the baseline levels(P<0.001).There were no differences in the saturation of peripheral oxygen,paO_(2),and paCO_(2) between the groups before anesthesia and before extubation(P>0.05).There were statistically significant differences in paO_(2) between the two groups before anesthesia and 1 h after extubation and immediately after extubation and 1 h after extubation(P<0.001).However,there were no significant differences in the oxygen tolerance score before leaving the room,airway humidification,and pulmonary complications 3 d after surgery between the two groups(P>0.05).CONCLUSION HFNCO can improve oxygen partial pressure and respiratory function in elderly patients undergoing orthopedic surgery under general endotracheal anesthesia.Thus,HFNCO can be used to prevent postoperative hypoxemia.展开更多
Long duration energy storage(LDES)technologies are vital for wide utilization of renewable energy sources and increasing the penetration of these technologies within energy infrastructures.Herein,we propose a low-cost...Long duration energy storage(LDES)technologies are vital for wide utilization of renewable energy sources and increasing the penetration of these technologies within energy infrastructures.Herein,we propose a low-cost alkaline all-iron flow battery by coupling ferri/ferro-cyanide redox couple with ferric/ferrous-gluconate complexes redox couple.The designed all-iron flow battery demonstrates a coulombic efficiency of above 99%and an energy efficiency of~83%at a current density of80 m A cm^(-2),which can continuously run for more than 950 cycles.Most importantly,the battery demonstrates a coulombic efficiency of more than 99.0%and an energy efficiency of~83%for a long duration(~12,16 and 20 h per cycle)charge/discharge process.Benefiting from the low cost of iron electrolytes,the overall cost of the all-iron flow battery system can be reached as low as$76.11 per k Wh based on a10 h system with a power of 9.9 k W.This work provides a new option for next-generation cost-effective flow batteries for long duration large scale energy storage.展开更多
基金The research was funded by Science and Technology Project of Hebei Education Department(Project Number:QN2022198).Y.C.received the grant.
文摘This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by means of a fluid–structure interaction(FSI)method by which the descaling effect produced by rolling coils with different section sizes is examined.Assuming a flat fan-shaped nozzle at the entrance of the R1R2 roughing mill,the outflow field characteristics and the velocity distribution curve on the strike line(at a target distance of 30–120 mm)are determined.It is found that the velocity in the center region of the water jet with different target distances is higher than that in the boundary region.As the target distance increases,the velocity of the water jet in the central region decreases.Through comparison with experimental results,it is shown that the simulation model can accurately predict the impact position of the high-pressure water on the impact plate,thereby providing a computational scheme that can be used to optimize the nozzle space layout and improve the slabs’descent effect for different rolling specifications.
基金support primarily from the U.S.Department of Energy Advanced Research Projects Agency-Energy 2015 OPEN program under Contract No.67995support by Energy Storage Materials Initiative(ESMI),which is a Laboratory Directed Research and Development Project at Pacific Northwest National Laboratory(PNNL).PNNL is a multiprogram national laboratory operated for the U.S.Department of Energy(DOE)by Battelle Memorial Institute under Contract no.DE-AC05-76RL01830.
文摘The hydrogen-iron(HyFe)flow cell has great potential for long-duration energy storage by capitalizing on the advantages of both electrolyzers and flow batteries.However,its operation at high current density(high power)and over continuous cycling testing has yet to be demonstrated.In this paper,we discuss our design and demonstration of a water management strategy that supports high current and long cycling performance of a HyFe flow cell.Water molecules associated with the movement of protons from the iron electrode to the hydrogen electrode are sufficient to hydrate the membrane and electrode at a low current density of 100 mA cm^(-2)during the charge process.At higher charge current density,more aggressive measures must be taken to counter back-diffusion driven by the acid concentration gradient between the iron and hydrogen electrodes.Our water management approach is based on water vapor feeding in the hydrogen electrode,and water evaporation in the iron electrode,thus enabling the high current density operation of 300 mA cm^(-2).
基金supported by the National Natural Science Foundation of China(22179019)the Natural Science Foundation of Hebei Province,China(B2020501003)the Fundamental Research Funds for the Central Universities(N2023030)。
文摘Zinc-based flow batteries(ZFBs)have aroused great favor in large-scale energy storage due to the high security and low cost.However,the low areal capacity arising from the limited space for Zn plating hinders the further development.Herein,a novel carbon felt-Sn-carbon felt sandwich host(CSCH)is designed and constructed.Benefiting from the strong chemical absorption and the dehydration effect on Zn(H_(2)O)_(6)^(2+),the Sn activation layer in the CSCH demonstrates the lowest comprehensive resistance for Zn deposition.Thus,Zn is induced to nucleate preferentially on the Sn activation layer,and grows towards the membrane,regulating the spatial distribution of Zn electrochemical deposits,which remarkably improves the areal capacity and cyclic stability of Zn anode.Consequently,the zinc-bromine flow batteries equipped with CSCH electrodes can achieve the ultra-high areal capacity of 120 mA h cm^(-2)at 80 mA cm^(-2),and run stably for 140 h with average energy efficiency of 80.3%in the extreme condition(80 mA cm^(-2),80 mA h cm^(-2)).This innovative work will inspire future advanced designs for high areal capacity electrodes in ZFBs.
基金Supported by Foundation of the General Hospital of Western Command,No.2021-XZYG-C04。
文摘BACKGROUND High flow priapism(HFP)is a rare type of priapism.Perineal trauma is the most common cause of HFP.Trauma-induced penile artery injury may lead to an arterial-cavernosal fistula,whereas persistent irregular arterial blood flow entering the corpora cavernosum can cause a persistent penile erection.The routine treatment of HFP focuses on addressing the abnormal penile erectile status and avoiding post-treatment erectile dysfunction.Interventional embolization is an important therapeutic modality for HFP,and bilateral embolization therapy is currently the most commonly used technique for patients with bilateral cavernous artery fistulas;however,unilateral embolization therapy has yet to be reported.CASE SUMMARY Herein,we report of the case of a 26-year-old Chinese male who presented with a persistent abnormal erection for 12 h after perineal impact injury.Medical history,cavernous arterial blood gas analysis and radiological examinations led to a diagnosis of HFP caused by bilateral cavernous artery fistulas.We performed routine conservative treatment(compression therapy and ice application)for the patient after admission;however,10 d later,his symptoms had not been relieved.After completion of the preoperative workup,right(severe side)selective perineal artery embolization was performed;the left cavernous artery fistula was left untreated.After postoperative continuation of conservative treatment for 72 h,the patient experienced complete penile thinning.The patient had no symptoms of erectile dysfunction over a follow-up period of 12 mo.CONCLUSION Compared with bilateral cavernous artery fistula embolization,we believe that unilateral cavernous artery fistula embolization can achieve positive clinical efficacy and reduce the risk of postoperative erectile dysfunction secondary to penile ischemia.
文摘Arteriovenous fistulas have a substantial impact on systemic hemodynamics, however their effect on extracorporeal circulation is not well understood. We report our clinical observation on the management under extracorporeal circulation of a patient with renal insufficiency with a high-flow arteriovenous fistula. This is a 59-year-old man who was referred to us for surgical treatment of ischemic coronary artery disease in a context of anuric chronic renal failure. Hypothermia at 32°C is started from the start in CEC due to hyperflow at the level of the arteriovenous fistula. We performed two coronary artery bypasses of the marginal and IVA via the two internal thoracic arteries. The patient is hemofiltered in order to avoid hyperkalaemia and possibly avoid fluid overload related to filling per CEC. The clamping time was 71 minutes and the SCC lasted 141 minutes. There was no homologous transfusion in the operating room. It turns out that the input/output balance is zero at the end of the CEC. The postoperative course was simple.
基金Supported by Sinopec Key Science and Technology Research Project(P21060)。
文摘The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.
文摘In order to improve the reliability of the spacecraft micro cold gas propulsion system and realize the precise control of the spacecraft attitude and orbit, a micro-thrust, high-precision cold gas thruster is carried out, at the same time due to the design requirements of the spacecraft, this micro-thrust should be continuous working more than 60 minutes, the traditional solenoid valve used for the thrusts can’t complete the mission, so a long-life micro latching valve is developed as the control valve for this micro thruster, because the micro latching valve can keep its position when it cuts off the outage. Firstly, the authors introduced the design scheme and idea of the thruster. Secondly, the performance of the latching valve and the flow characteristics of the nozzle were simulated. Finally, from the experimental results and compared with the numerical study, it shows that the long-life micro cold gas thruster developed in this paper meets the mission requirements.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2007AA05Z207)National Science and Technology Support Scheme of China (Grant No. 2008BAF34B10)Jiangsu Provincial Graduate Student Innovation Foundation of China (Grant No. CX08B_064Z)
文摘The experimental investigation of axial-flow pump has been rapidly developed to meet the needs of South-to-North Water Diversion Project of China. Owing to the boundary conditions of hub, blade tip clearance, much of the physical phenomena and laws involved in this complex flow field can't be fully determined. The flow characteristics of the high efficiency axial-flow pump have been simulated by RNG k-e turbulence model and SIMPLEC arithmetic based on FLUENT software. Numerical results indicate that the data from the prediction show agreement with the experimental results, static pressure on pressure side of blades increases slightly at circumferential direction with radius increasing, and keep almost constant at the same radial while increasing gradually from inlet to exit on the suction side along flow direction at design conditions. The static pressure, total pressure and velocity at inlet, impeller outlet and vane outlet were measured by a five-hole probe, and a contrastive experiment was done to investigate the influence of hub leakage. The experimental results show that inlet flow is almost axial and the prerotation is very small at various conditions. The meridional velocity and circulation distribution are almost identical at impeller outlet at design conditions due to steady flow and high efficiency. The residual circulation exits at downstream of the guide vane, and the circumferential velocity component increases linearly from hub to tip at small flow rate conditions. Hub leakage in adjustable blades results in the decrease of the meridional velocity and circulation at blade exit near hub. The results of numerical simulation and experiments supply important flow structure information for the high-efficiency axial-flow pump.
基金The project supported by the National Natural Science Foundation of China(10172017)Aeronautical Science Foundation of China(02A51048)Foundation of National Key Laboratory of Aerodynamic Design and Research(51462020504HK0101)
文摘The studies of asymmetric vortices flow over slender body and its active control at high angles of attack have significant importance for both academic field and engineering area.This paper attempts to provide an update state of art to the investigations on the fields of forebody asymmetric vortices.This review emphasizes the correlation between micro-perturbation on the model nose and its response and evolution behaviors of the asymmetric vortices.The critical issues are discussed, which include the formation and evolution mechanism of asymmetric multi-vortices;main behaviors of asymmetric vortices flow including its deterministic feature and vortices flow structure;the evolution and development of asymmetric vortices under the perturbation on the model nose;forebody vortex active control especially discussed micro-perturbation active control concept and technique in more detail.However present understanding in this area is still very limited and this paper tries to identify the key unknown problems in the concluding remarks.
基金Supported by the National Key Research and Development Program of China(2016YFB0303000)the National Natural Science Foundation of China(51803187)Zhejiang Provincial Natural Science Foundation of China(LQ18E030011)
文摘The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and experiment.Falling film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film thickness.The comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good agreement.The simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental results.This work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.
基金Project(U1534210)supported by the National Natural Science Foundation of ChinaProject(14JJ1003)supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(2015CX003)supported by the Project of Innovation-driven Plan in Central South University,ChinaProject(14JC1003)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2015T002-A)supported by the Technological Research and Development program of China Railways Cooperation
文摘In order to describe an investigation of the flow around high-speed train on a bridge under cross winds using detached-eddy simulation(DES), a 1/8th scale model of a three-car high-speed train and a typical bridge model are employed, Numerical wind tunnel technology based on computational fluid dynamics(CFD) is used, and the CFD models are set as stationary models. The Reynolds number of the flow, based on the inflow velocity and the height of the vehicle, is 1.9×10~6. The computations are conducted under three cases, train on the windward track on the bridge(WWC), train on the leeward track on the bridge(LWC) and train on the flat ground(FGC). Commercial software FLUENT is used and the mesh sensitivity research is carried out by three different grids: coarse, medium and fine. Results show that compared with FGC case, the side force coefficients of the head cars for the WWC and LWC cases increases by 14% and 29%, respectively; the coefficients of middle cars for the WWC and LWC increase by 32% and 10%, respectively; and that of the tail car increases by 45% for the WWC whereas decreases by 2% for the LWC case. The most notable thing is that the side force and the rolling moment of the head car are greater for the LWC, while the side force and the rolling moment of the middle car and the tail car are greater for the WWC. Comparing the velocity profiles at different locations, the flow is significantly influenced by the bridge-train system when the air is close to it. For the three cases(WWC, LWC and FGC), the pressure on the windward side of train is mostly positive while that of the leeward side is negative. The discrepancy of train's aerodynamic force is due to the different surface area of positive pressure and negative pressure zone. Many vortices are born on the leeward edge of the roofs. Theses vortices develop downstream, detach and dissipate into the wake region. The eddies develop irregularly, leading to a noticeably turbulent flow at leeward side of train.
基金Project supported by the National Natural Science Foundation of China (Grant No 70271069).
文摘By coupling the non-equilibrium extrapolation scheme for boundary condition with the multi-relaxation-time lattice Boltzmann method, this paper finds that the stability of the multi-relaxation-time model can be improved greatly, especially on simulating high Reynolds number (Re) flow. As a discovery, the super-stability analysed by Lallemand and Luo is verified and the complex structure of the cavity flow is also exhibited in our numerical simulation when Re is high enough. To the best knowledge of the authors, the maximum of Re which has been investigated by direct numerical simulation is only around 50 000 in the literature; however, this paper can readily extend the maximum to 1000 000 with the above combination.
基金Supported by the National Natural Science Foundation of China (No.50576088), the Natural Science Foundation of ZhejiangProvince (No.R503170) and the Doctoral Program Foundation of Ministry of Education (No.20030335009).
基金"Le Studium Loire Valley Institute for Advanced Studies" and "Region Centre Val de Loire"through the "OBAMA" project under Lavoisier Ⅱ for financial support。
文摘A protic ionic liquid is designed and implemented for the first time as a solvent for a high energy density vanadium redox flow battery.Despite being less conductive than standa rd aqueous electrolytes,it is thermally stable on a 100 ℃ temperature window,chemically stable for at least 60 days,equally viscous and dense with typical aqueous solvents and most importantly able to solubilize to 6 mol L^(-1) vanadium sulfate,thus increasing the VRFB energy density by a factor of 2.5.Electrochemical measurements revealed quasi-reversible redox transitions for both catholyte and anolyte at 25 ℃ while a proof-of-concept redox flow cell with the proposed electrolyte was tested for a total of 150 cycles at 25 ℃,showing an open circuit potential of 1.39 V and energy and coulombic efficiencies of 65% and 93%,respectively.What’s more,the battery can be equally cycled at 45℃ showing good thermal stability.This study underlines a new route to improve the energy-to-volume ratio of energy storage system.
文摘High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously.A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system.A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design.Mathematical models of the opening process and flow rate of the valve are established.Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response.Corresponding formulas to solve 4 parts of the response time are derived.Key factors that influence the opening response time are analyzed.According to the mathematical model of the valve,a simulation of the opening process is carried out by MATLAB.Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve.Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool.The experimental results are in agreement with the simulated results,therefore the validity of the theoretical analysis is verified.Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa.The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s.According to the result of the load driving test,the valve can meet the demands of the driving system.The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.
文摘A new method for the determination of trace non-rare earth elements in high purity rare earth oxides by ICP-AES with preconcentration on an active carbon-silica gel microcolumn in a flow injection system is described in this paper. Experimental parameters such as pH, flow rate,reagent concentration,length of reaction coil,eluent acidity,etc. were optimized. In the buffer solution of NH3. H2O/NH4Cl at pH 4. 6,Al,Cr,Cu,Fe, Pb, V and Zn can be preconcentrated and then eluted with 4. 5 mol/L nitric acid utilizing stop-flow technique. The enrichment factors were in range of 8. 1 ̄12. 6 with detection limits of μg/m level ,and the RSD with metals at μg/g level were 2. 3 ̄5. 0% (n= 7). The method proposed can reduce the matrix interference effectively , and has been applied to the determination of non-rare earth metals atμg/g level in high purity Eu2O3 with satisfactory results.
文摘On the basis of the data obtained on Gleeble 1500 Thermal Simulator, the predicting models for the relation between stable flow stress during high temperature plastic deformation and deformation strain, strain rate and temperature for 1420 Al Li alloy have been developed with BP artificial neural networks method. The results show that the model on basis of BPNN is practical and it reflects the actual feature of the deforming process. It states that the difference between the actual value and the output of the model is in order of 5%. [
文摘BACKGROUND Hypoxemia is a common complication in older patients during postoperative recovery and can cause pulmonary complications.Therefore,reducing the incidence of postoperative hypoxemia is a clinical concern.AIM To investigate the clinical efficacy of high-flow nasal cannula oxygen(HFNCO)in the resuscitation period of older orthopedic patients.METHODS In this prospective randomized controlled trial,60 older patients who underwent orthopedic surgery under general anesthesia were randomly divided into two groups:those who used conventional face mask and those who used HFNCO.All patients were treated with 60%oxygen for 1 h after extubation.Patients in the conventional face mask group were treated with a combination of air(2 L)and oxygen(2 L)using a traditional mask,whereas those in the HFNCO group were treated with HFNCO at a constant temperature of 34℃ and flow rate of 40 L/min.We assessed the effectiveness of oxygen therapy by monitoring the patients’arterial blood gas,peripheral oxygen saturation,and postoperative complications.RESULTS The characteristics of the patients were comparable between the groups.One hour after extubation,patients in HFNCO group had a significantly higher arterial partial pressure of oxygen(paO_(2))than that of patients in conventional face mask group(P<0.001).At extubation and 1 h after extubation,patients in both groups showed a significantly higher arterial partial pressure of carbon dioxide(paCO_(2))than the baseline levels(P<0.001).There were no differences in the saturation of peripheral oxygen,paO_(2),and paCO_(2) between the groups before anesthesia and before extubation(P>0.05).There were statistically significant differences in paO_(2) between the two groups before anesthesia and 1 h after extubation and immediately after extubation and 1 h after extubation(P<0.001).However,there were no significant differences in the oxygen tolerance score before leaving the room,airway humidification,and pulmonary complications 3 d after surgery between the two groups(P>0.05).CONCLUSION HFNCO can improve oxygen partial pressure and respiratory function in elderly patients undergoing orthopedic surgery under general endotracheal anesthesia.Thus,HFNCO can be used to prevent postoperative hypoxemia.
基金the financial support from National Natural Science Foundation of China(22078313,21908214 and 21925804)the Dalian High Level Talent Innovation support program(2020RD05)+2 种基金the Dalian Young Star of Science and Technology(2021RQ122)the Free exploring basic research project of Liaoning(2022JH6/100100005)the Youth Innovation Promotion Association CAS(2019182)。
文摘Long duration energy storage(LDES)technologies are vital for wide utilization of renewable energy sources and increasing the penetration of these technologies within energy infrastructures.Herein,we propose a low-cost alkaline all-iron flow battery by coupling ferri/ferro-cyanide redox couple with ferric/ferrous-gluconate complexes redox couple.The designed all-iron flow battery demonstrates a coulombic efficiency of above 99%and an energy efficiency of~83%at a current density of80 m A cm^(-2),which can continuously run for more than 950 cycles.Most importantly,the battery demonstrates a coulombic efficiency of more than 99.0%and an energy efficiency of~83%for a long duration(~12,16 and 20 h per cycle)charge/discharge process.Benefiting from the low cost of iron electrolytes,the overall cost of the all-iron flow battery system can be reached as low as$76.11 per k Wh based on a10 h system with a power of 9.9 k W.This work provides a new option for next-generation cost-effective flow batteries for long duration large scale energy storage.