1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-...1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.展开更多
This article comments on the article by Du et al,who conducted a randomized controlled trial aiming at evaluating the effectiveness of a novel spray flushing system in cleaning flexible endoscopes while minimizing dam...This article comments on the article by Du et al,who conducted a randomized controlled trial aiming at evaluating the effectiveness of a novel spray flushing system in cleaning flexible endoscopes while minimizing damage to the working channels.We share our perspective on the importance of improving endoscope reprocessing methods.The findings highlight the spray flushing system's capacity to improve cleaning efficacy while minimizing damage,suggesting that it might be important in enhancing endoscope reprocessing procedures.展开更多
To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug ...To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug loading.By advanced spray drying,attapulgite was transformed into microspheres,refining its drug release characteristics.Various parameters were examined,achieving optimal particle size and morphology at 25%solid content,2.5%dispersant,and 3% binder.Attapulgite microspheres demonstrated exceptional encapsulation efficiency,exceeding 95% for doxorubicin hydrochloride,highlighting their versatility in drug delivery.FTIR and XRD were used to predict changes in material properties after spray drying.Notably,cytotoxicity tests confirmed the high biocompatibility of attapulgite microspheres,devoid of cell death induction.Attapulgite microsphere loaded with doxorubicin enable sustained drug release and maintain killing ability against tumor cells.This study confirms the viability of spray dried attapulgite microspheres for efficient drug loading and delivery and provides insights for innovative drug delivery systems that utilize the unique properties of attapulgite to advance therapeutics.展开更多
Background Feeding spray dried plasma(SDP)to weanling pigs improves growth,but there is a lack of research on how SDP impacts oxidative stress and inflammatory response in lactating sows,and performance of their pigle...Background Feeding spray dried plasma(SDP)to weanling pigs improves growth,but there is a lack of research on how SDP impacts oxidative stress and inflammatory response in lactating sows,and performance of their piglets after weaning.Therefore,an experiment was conducted to test the hypothesis that sows fed a diet with SDP in late gestation and lactation have improved reproductive performance and reduced inflammation compared with sows fed no SDP.The second hypothesis was that pigs weaned from sows fed 0.5%SDP in lactation have reduced diarrhea incidence and improved growth performance during the initial 14 d of the nursery period regardless of dietary SDP.Results The percent of low vitality or starved pigs during lactation was less(P<0.05)from sows fed 0.5%dietary SDP compared with sows fed the diet without SDP.Dietary SDP did not influence oxidative stress markers in the plasma of sows,but serum cytokines increased(P<0.05)in sows fed the diet with 0.5%SDP compared with sows fed the diet without SDP.Pigs weaned from young sows fed no SDP or from mature sows fed 0 or 0.5%SDP had a greater gain to feed ratio when fed a phase 1 diet containing 6%SDP compared with pigs fed a diet without SDP,but the gain to feed ratio of pigs weaned from young sows fed 0.5%dietary SDP was not affected by dietary SDP in phase 1(interaction,P<0.05).Regardless of sow treatment,pigs fed a phase 1 diet with 6%SDP had greater(P<0.05)growth performance than pigs fed a phase 1 diet without SDP,and pigs fed the phase 1 diet with 6%SDP had reduced(P<0.05)diarrhea incidence in phase 1.Conclusions Feeding 0.5%dietary SDP to sows may reduce the number of mummified pigs and increase pig vitality during lactation,but adding 0.5%SDP to sow diets during lactation did not improve post-weaning performance of pigs fed a starter diet with 6%SDP.展开更多
This study examines how ball milling parameters,specifically rotational speeds(20,40,and 60 r/min)in dry and wet condi-tions,affect the development of mullite/5wt%nano-fly ash coatings on AISI 410 steel,focusing on th...This study examines how ball milling parameters,specifically rotational speeds(20,40,and 60 r/min)in dry and wet condi-tions,affect the development of mullite/5wt%nano-fly ash coatings on AISI 410 steel,focusing on their impact on feedstock powders and plasma-sprayed coatings.Optimized milling parameters at 60 r/min under wet conditions yielded high-quality feedstock powders with a particle size of 14μm and limited size distribution.Coatings produced from wet-milled powders demonstrated a higher deposition effi-ciency(35%)due to their smaller,uniformly distributed particles,which enhanced melting during the spraying process.These coatings also exhibited significantly lower porosity(7.9%),resulting in denser structures with superior mechanical properties,including a hardness of HV_(1)647,fracture toughness of 1.41 MPa·m^(0.5),and a smoother surface finish with a roughness(R_(a))of 6.1μm.Residual stress analysis showed that wet-milled coatings had higher residual stresses,reaching up to 165.95 MPa,compared to dry-milled coatings.This increase is attributed to finer particle sizes and rapid thermal cycling during deposition,which intensified tensile stresses within the coating.These results highlight the importance of optimizing milling parameters to enhance coating performance and process efficiency.展开更多
[Objectives]To establish a high-performance liquid chromatography(HPLC)method for the simultaneous determination of forsythin,baicalin,and chlorogenic acid in a traditional Chinese medicine spray disinfectant.[Methods...[Objectives]To establish a high-performance liquid chromatography(HPLC)method for the simultaneous determination of forsythin,baicalin,and chlorogenic acid in a traditional Chinese medicine spray disinfectant.[Methods]The chromatographic separation was performed on a GL Sciences(19H0044724)-C_(18)column(4.6 mm×250 mm,5μm)with a mobile phase of acetonitrile-0.05%formic acid solution at a flow rate of 1 mL/min.The injection volume was 10μL,detection wavelength was set at 280 nm,and column temperature was maintained at 25℃.[Results]The linear ranges of forsythin,baicalin,and chlorogenic acid were 10.5-52.5,20.6-103,and 14.2-71μg/mL,respectively,with good linear relationships between concentration and peak area(R^(2)=0.9999).The relative standard deviations(RSD s)for precision and repeatability tests were all≤1.0%.The average recoveries were 98.51%,98.48%,and 97.71%for the three components,with RSD s of 0.96%,0.97%,and 0.73%,respectively.[Conclusions]This method demonstrates strong specificity,high precision,excellent accuracy,and simplicity of operation,making it suitable for the simultaneous quantification of forsythin,baicalin,and chlorogenic acid in traditional Chinese medicine spray disinfectants.It provides a reliable basis for quality control and practical applications in animal breeding environments.展开更多
Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.Thi...Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.This paper presents a high-fidelity numerical study of liquidatomization and spray combustion under high-pressure conditions,emphasizing the effects of pres-sure oscillations on the flow evolution and combustion dynamics.The theoretical framework isbased on the three-dimensional conservation equations for multiphase flows and turbulent combus-tion.The numerical solution is achieved using a coupling method of volume-of-fluid and Lagran-gian particle tracking.The Zhuang-Kadota-Sutton(ZKS)high-pressure evaporation model andthe eddy breakup-Arrhenius combustion model are employed.Simulations are conducted for amodel combustion chamber with impinging-jet injectors using liquid oxygen and kerosene as pro-pellants.Both conditions with and without inlet and outlet pressure oscillations are considered.Thefindings reveal that pressure oscillations amplify flow fluctuations and can be characterized usingkey physical parameters such as droplet evaporation,chemical reaction,and chamber pressure.The spectral analysis uncovers the axial variations of the dominant and secondary frequenciesand their amplitudes in terms of the characteristic physical quantities.This research helps establisha methodology for exploring the coupling effect of liquid atomization and spray combustion.It alsoprovides practical insights into their responses to pressure oscillations during the occurrence ofcombustion instability.This information can be used to enhance the design and operation ofliquid-fueled propulsion engines.展开更多
Objective:This study investigates the preventive and therapeutic effects of medical radiation protection spray(Bergmann)compared to triethanolamine cream in patients undergoing radiotherapy following breast cancer sur...Objective:This study investigates the preventive and therapeutic effects of medical radiation protection spray(Bergmann)compared to triethanolamine cream in patients undergoing radiotherapy following breast cancer surgery.Methods:Ninety patients with breast cancer who received postoperative radiotherapy between July 2018 and July 2021 were randomly divided into the Bergmann treatment(experimental)group and the triethanolamine cream treatment(control)group,with 45 patients in each group.Radiodermatitis severity was assessed using the RTOG radiodermatitis grading standards.Results:The radiation dose required to develop grade I radiodermatitis was significantly higher in the experimental group compared to the control group,at(36.13±1.17 Gy)and(25.38±0.63 Gy),respectively.At a radiation dose of 30 Gy,the proportion of grade I radiodermatitis cases in the experimental group was significantly lower than in the control group(P=0.002).At radiation doses of 40 Gy and 50 Gy,the proportion of grade II radiodermatitis cases in the experimental group was also significantly lower than in the control group(P<0.001).No cases of grade III or higher radiodermatitis were observed in the experimental group,while three cases of grade III radiodermatitis occurred in the control group,although the difference was not statistically significant.No patients in the experimental group discontinued treatment due to radiodermatitis or mucosal reactions,whereas two patients in the control group interrupted treatment due to these reactions but eventually completed therapy.Conclusion:Bergmann spray effectively prevents radiodermatitis in patients undergoing radiotherapy after breast cancer surgery and is more effective than triethanolamine cream in treating skin lesions.Its ease of use improves the quality of life for patients undergoing radiotherapy and ensures successful treatment completion.Bergmann is suitable for clinical promotion and application.展开更多
This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions....This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions.It proposes the idea of introducing spray pyrolysis technology into the rare earth extraction and separation processes.This paper briefly describes the development history of chloride spray pyrolysis technology,focusing on the research status and application progress of rare earth chloride solution and magnesium chloride solution spray pyrolysis technology,as well as spray pyrolysis equipment.The paper also analyzes the challenges and technical intricacies associated with applying spray pyrolysis technology to chloride solutions in the rare earth extraction and separation processes.Additionally,it explores future trends and proposes strategies to facilitate the full recycling of acids and bases,streamline the process flow,and enhance the prospects for green and low-carbon rare earth metallurgy.展开更多
The advancement in endoscopic technology and techniques has increased its use in the diagnosis and treatment of gastrointestinal diseases.Reprocessing of reusable endoscopes remains a challenge.Inadequate reprocessing...The advancement in endoscopic technology and techniques has increased its use in the diagnosis and treatment of gastrointestinal diseases.Reprocessing of reusable endoscopes remains a challenge.Inadequate reprocessing leads to bacterial contamination of the endoscope,a significant cause of endoscope-related infections.To thoroughly address the complexities of cleaning a flexible endo-scope,various cleaning methods have been devised and tested across different studies.This letter evaluates one such method,spray flushing for flexible gastro-scopes,developed and tested in a randomized controlled trial by Du et al.Based on the post-processing test results for this method,Du et al conclude that there is improved cleaning efficacy and reduced damage compared to manual brush cleaning.The validity and reliability of the results could be further enhanced by carefully considering the study design and a few underlying concepts that contribute to the reprocessing quality of different types of endoscopes.展开更多
Delay tolerant wireless sensor networks(DTWSN)is a class of wireless network that finds its deployment in those application scenarios which demand for high packet delivery ratio while maintaining minimal overhead in o...Delay tolerant wireless sensor networks(DTWSN)is a class of wireless network that finds its deployment in those application scenarios which demand for high packet delivery ratio while maintaining minimal overhead in order to prolong network lifetime;owing to resource-constrained nature of sensors.The fundamental requirement of any network is routing a packet from its source to destination.Performance of a routing algorithm depends on the number of network parameters utilized by that routing protocol.In the recent years,various routing protocol has been developed for the delay tolerant networks(DTN).A routing protocol known as spray and wait(SnW)is one of the most widely used routing algorithms for DTN.In this paper,we study the SnW routing protocol and propose a modified version of it referred to as Pentago SnW which is based on pentagonal number series.Comparison to binary SnW shows promising results through simulation using real-life scenarios of cars and pedestrians randomly moving on a map.展开更多
Dual Synthetic Jets (DSJ) can directly affect the development of spray through the complex vortex structure. The mechanism of flow control on spray and its thermal management application are studied by combining exper...Dual Synthetic Jets (DSJ) can directly affect the development of spray through the complex vortex structure. The mechanism of flow control on spray and its thermal management application are studied by combining experiment and simulation. The spray characteristics under different injection angles are studied, and the results show that the angle should be controlled in the range of 45°–60°, so that sufficient momentum transfer can be obtained, and meanwhile spray impingement area narrowing can be avoided. The spray characteristics under flow control of DSJ with different Reynolds numbers are studied, and the results show that Reynolds number should be controlled in the range of 2859–3574, so that strong particle streamwise acceleration and wall film disturbing can be achieved. In addition, the DSJ kinetic energy is utilized more efficiently. On the basis of previous research, this paper proposes a novel active heat pipe based on spray controlled by DSJ. The space occupancy has been reduced by more than 60%. Even in a sealed state, the active heat pipe is able to cool a hot surface with heat flux of 22.2 kW/m^(2) from 111℃ to 57℃ only in 20 s. The noise of DSJ is reduced from 85 dB to 60 dB, which is expected to promote the practical application of DSJ in thermal management.展开更多
Cold spray(CS)has been attracting an increasing interest due to low heat input,which avoids grain growth and high thermal stress.This feature is beneficial for high damping Mn-Cu alloy through limiting oxidation and f...Cold spray(CS)has been attracting an increasing interest due to low heat input,which avoids grain growth and high thermal stress.This feature is beneficial for high damping Mn-Cu alloy through limiting oxidation and formation of hot cracks.However,high dislocation density formed because of extensive plastic deformation,pores,and cracks result in the low damping capacity in the as-deposited Mn-Cu alloy.New strategy was introduced for improving damping capacity in cold sprayed Mn-20Cu-5Ni-2Fe(M2052 at%)alloy with different particle sizes(below 25μm and between 15 and 53μm).The 15-53μm powder has high yield strength and plastic deformation resistance,which leads to a large number of defects and non-bonded interface between powders due to insufficient plastic deformation.Ageing treatment at 420℃leads to spinodal decomposition of the fcc-austenite,and the formation of Mn-rich matrix and Cu-rich nanoscale network structure is found.Under the same ageing conditions,the spinodal decomposition level of the fcc-austenite in the CS M2052 alloy with the particles of 15-53μm is higher than that with the particles of<25μm,which results from the difference in the grain size.As a result,the damping capacity in the CS M2052 samples with particle size of 15-53μm is higher compared with the CS M2052 sample with particle size of<25μm.There is a significant increase in the damping capacity in the CS M2052 samples after HIP treatment,which can effectively reduce the internal defects and improve the bonding properties between powders.展开更多
Pitting corrosion poses a significant challenge to 9Cr18 high-carbon chromium bearing steel in chloride-rich environments,severely compromising its structural integrity.The study systematically investigates the pittin...Pitting corrosion poses a significant challenge to 9Cr18 high-carbon chromium bearing steel in chloride-rich environments,severely compromising its structural integrity.The study systematically investigates the pitting behaviour of 9Cr18 bearing steel under salt spray conditions,focusing on the progressive evolution of surface morphology and cross-sectional characteristics of pits on finished bearings.Scanning electron microscopy,energy-dispersive spectroscopy and X-ray diffraction were employed to examine the surface morphology,elemental composition and phase structure of corrosion products over varying salt spray exposure durations.The results show that 9Cr18 steel exhibits localized pitting with“volcanic crater”-like pits in the early stage of salt spray corrosion.After 48 h,pitting develops into a“multi-point”pattern,marking the initial transition toward uniform corrosion.Until 240 h,corrosion products completely cover the surface,indicating the complete transformation from localized pitting to uniform corrosion.The high carbon and chromium content in 9Cr18 steel promotes carbide precipitation and uneven distribution in the matrix.Cr-depleted regions near the carbide/matrix interface serve as preferential sites for pitting initiation.The low effective utilization of chromium reduces the overall corrosion resistance of 9Cr18.展开更多
The corrosion resistance of aluminum(Al)cable-copper(Cu)terminal joints fabricated by magnetic pulse crimping(MPC)and hydraulic clamp crimping(HCC)was compared.Performance degradation was evaluated by mechanical and e...The corrosion resistance of aluminum(Al)cable-copper(Cu)terminal joints fabricated by magnetic pulse crimping(MPC)and hydraulic clamp crimping(HCC)was compared.Performance degradation was evaluated by mechanical and electrical properties.Additionally,corrosion behavior was analyzed by electrochemical testing.Microscopic characterization was performed by scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Results show that the tensile strength of the corroded joints is reduced.However,due to the advantages of high-speed forming and contact tightness unique to MPC,the contact resistance of the corroded joints still maintains excellent.Electrochemical tests demonstrate that the MPC joints have higher corrosion potentials and smaller corrosion currents,providing better corrosion resistance.The formation of a primary battery between Al and Cu at the lap joint leads to the formation of severer corrosion pits.展开更多
Nickel-rich cathode materials have received widespread attention due to their high energy density.However,the poor rate capability and inferior cycle stability seriously hinder their large-scale application.The tradit...Nickel-rich cathode materials have received widespread attention due to their high energy density.However,the poor rate capability and inferior cycle stability seriously hinder their large-scale application.The traditional co-precipitation method for preparing them has a long process and easily arises agglomeration leading to inhomogeneous element distribution.Here,a novel precursor containing Li element was prepared by ultrafast spray pyrolysis(SP)in 3–5 s.Then the precursor was used to synthesize pristine LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90)and 1%Mg modified LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90-Mg1).This method gets rid of mixing Li/Mg source and the precursor prepared by common co-precipitation,thus could achieve homogeneous lithiation and Mg2+doping.The cell parameter c is expanded,and the cation disorder is reduced after Mg2+doping.Furthermore,the harmful H2-H3 phase transition in NCM90-Mg1 is also well suppressed.As a result,the obtained NCM90-Mg1 shows better electrochemical performance than NCM90.Within 2.8–4.3 V(25℃),the specific discharge capacity of NCM90-Mg1 at 5 C is as high as 169.1m Ah/g,and an outstanding capacity retention of 70.0%(10.0%higher than NCM90)can be obtained after400 cycles at 0.5 C.At 45℃,a capacity retention of 81.9%after 100 cycles at 1 C is recorded for NCM90-Mg1.Moreover,the NCM90-Mg1 also exhibits superior cycle stability when cycled at high cut-off voltage(4.5 V,25℃),possessing the capacity retention of 79.2%after 200 cycles at 1 C.Therefore,SP can be proposed as a powerful method for the preparation of multi-element materials for next-generation high energy density LIBs.展开更多
Large interfacial strains in particles are crucial for promoting bonding in cold spraying(CS),initiated either by adiabatic shear instability(ASI)due to softening prevailing over strain hardening or by hydrostatic pla...Large interfacial strains in particles are crucial for promoting bonding in cold spraying(CS),initiated either by adiabatic shear instability(ASI)due to softening prevailing over strain hardening or by hydrostatic plasticity,which is claimed to promote bonding even without ASI.A thorough microstructural analysis is vital to fully understand the bonding mechanisms at play during microparticle impacts and throughout the CS process.In this study,the HEA CoCrFeMnNi,known for its relatively high strain hardening and resistance to softening,was selected to investigate the microstructure characteristics and bonding mech-anisms in CS.This study used characterization techniques covering a range of length scales,including electron channeling contrast imaging(ECCI),electron backscatter diffraction(EBSD),and high-resolution transmission microscopy(HR-TEM),to explore the microstructure characteristics of bonding and overall structure development of CoCrFeMnNi microparticles after impact in CS.HR-TEM lamellae were prepared using focused ion beam milling.Additionally,the effects of deformation field variables on microstructure development were determined through finite element modeling(FEM)of microparticle impacts.The ECCI,EBSD,and HR-TEM analyses revealed an interplay between dislocation-driven processes and twinning,leading to the development of four distinct deformation microstructures.Significant grain refinement occurs at the interface through continuous dynamic recrystallization(CDRX)due to high strain and temperature rise from adiabatic deformation,signs of softening,and ASI.Near the interface,a necklace-like structure of refined grains forms around grain boundaries,along with elongated grains,resulting from the coexistence of dynamic recovery and discontinuous dynamic recrystallization(DDRX)due to lower temperature rise and strain.Towards the particle or substrate interior,concurrent twinning and dislocation-mediated mechanisms refine the structure,forming straight,curved,and intersected twins.At the top of the particles,only deformed grains with a low dislocation density are observed.Our results showed that DRX induces microstructure softening in highly strained interface areas,facilitating atomic bonding in CoCrFeMnNi.HR-TEM investigation confirms the formation of atomic bonds between particles and substrate,with a gradual change in crystal lattice orientation from the particle to the substrate and the occurrence of some misfit dislocations and vacancies at the interface.Finally,the findings of this research suggest that softening and ASI,even in materials resistant to softening,are required to establish bonding in CS.展开更多
The spray characteristics of different regions downstream of swirl cups play a critical role in cold start and re-ignition of gas turbines.The spray measurements were performed at the fuel pressures of 0.5,0.8,1.0,1.5...The spray characteristics of different regions downstream of swirl cups play a critical role in cold start and re-ignition of gas turbines.The spray measurements were performed at the fuel pressures of 0.5,0.8,1.0,1.5,and 2.0 MPa and the fuel temperatures of-23,-13,-3,7,17 and 27℃,respectively.The droplet size,droplet velocity,droplet number,and instantaneous spatial spray image of sprays from an aviation kerosene Jet-A were measured using a two-component phase Doppler particle analyzer and a digital off-axis holography system.As the fuel pressure and temperature increase,the Sauter Mean Diameter(SMD)and spray non-uniformity of the Spray Shear Layer(SSL)gradually decrease.As the fuel pressure increases,the SMD and spray non-uniformity of the Central Toroidal Recirculation Zone(CTRZ)gradually decrease,and the slopes of these curves both decrease.As the fuel pressure increases,the SMD and spray nonuniformity of the CTRZ rapidly decrease at the fuel temperature of23℃,while slightly decrease at the fuel temperature of 27℃.The droplets in the CTRZ come from 3 different sources:simplex nozzle,venturi,and outside the CTRZ.As the fuel pressure increases,the proportion of droplets recirculated from outside the CTRZ decreases.This study proposed the concept of the“pressure critical point”for the swirl cups.As the fuel temperature decreases,the proportion of droplets recirculated from outside the CTRZ increases below the critical pressure,while decreases above the critical pressure.In addition,through the models of liquid film formation and breakup on the curved cylindrical wall,a semi-theoretical model was established to predict the SMD of SSL for swirl cups.The prediction uncertainty of this model is less than 6%for all 14 conditions in this paper.展开更多
The reduction of oxygen consumption is a key factor to improve the energy density of underwater Stirling engine.A series of fundamental experiments are carried out to elucidate the spray characteristics of soybean oil...The reduction of oxygen consumption is a key factor to improve the energy density of underwater Stirling engine.A series of fundamental experiments are carried out to elucidate the spray characteristics of soybean oil/2,5-dimethylfuran(DMF)blended fuel in an underwater Stirling engine.Spray characteristics such as spray penetration,spray angle,spray area,and light intensity level under low injection and ambient pressures are obtained using image post-processing method.The results show that the effects of injection pressure,ambient pressure,and nozzle diameter on the transient spray characteristics of underwater Stirling engine are similar to those of diesel engine.However,in the steady spray process,the injection pressure has little effect on spray near angle,and the spray far angle increases with the increase of the injection pressure.Compared with the spray far angle at injection pressure of 3 MPa,the spray far angle at 5 MPa and 7 MPa increased by 11.38%and 18.14%respectively.The addition of DMF can obviously improve the atomization of soybean oil/DMF blended fuel.The spray angle of blended fuel in transient process increases with the increase of the DMF concentration.The spray near angle has exceeded that of diesel(46.21°)when the DMF volume fraction exceeds 25%.The spray far angle is equivalent to that of diesel when the DMF volume fraction reaches 75%.Moreover,the spray with gas ejection no longer keeps conical,the droplet diameter distribution is more dispersed,and the droplet diameter is smaller.展开更多
Cold spray,as a solid-state additive manufacturing process,has been attracting increasing attention from both scientific and industrial communities.However,cold-sprayed deposits generally have unfavorable mechanical p...Cold spray,as a solid-state additive manufacturing process,has been attracting increasing attention from both scientific and industrial communities.However,cold-sprayed deposits generally have unfavorable mechanical properties in their as-fabricated state compared to conventionally manufactured and fusion-based additive-manufactured counterparts due to the inherent microstructural defects in the deposits(e.g.,porosity and incomplete interparticle bonding).This downside reduces its competitiveness and limits its wide applications as an additive manufacturing process.In the past years,many strengthening technologies have been developed or introduced to adjust the microstructure and improve the mechanical properties of cold-sprayed deposits.The term“strengthening”in this work specifically refers to improving the mechanical strength,particularly the tensile strength of the cold-sprayed bulk deposits.According to the stage that the strengthening technologies are used in the cold spray process,they can be classified into three categories:pre-process(e.g.,powder heat treatment),in-process(e.g.,powder heating,in-situ micro-forging,laser-assisted cold spray),and post-process(e.g.,post heat treatment,hot isostatic pressing,hot rolling,friction stir processing).Therefore,a comprehensive review of these strengthening technolo-gies is conducted to illuminate the possible correlations between the strengthening mechanisms and the resultant deposit microstructures and mechanical properties.This review paper aims to help researchers and engineers well understand the different strengthening methods and provide guidance for the cold spray community to develop new strengthening strategies for future high-quality mass production.展开更多
基金supported by the National Natural Science Foundation of China(No.52061135101 and 52001078)the German Research Foundation(DFG,No.448318292)+3 种基金the Technology Innovation Guidance Special Foundation of Shaanxi Province(No.2023GXLH-085)the Fundamental Research Funds for the Central Universities(No.D5000240161)the Project of Key areas of innovation team in Shaanxi Province(No.2024RS-CXTD-20)The author Yingchun Xie thanks the support from the National Key R&D Program(No.2023YFE0108000).
文摘1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.
文摘This article comments on the article by Du et al,who conducted a randomized controlled trial aiming at evaluating the effectiveness of a novel spray flushing system in cleaning flexible endoscopes while minimizing damage to the working channels.We share our perspective on the importance of improving endoscope reprocessing methods.The findings highlight the spray flushing system's capacity to improve cleaning efficacy while minimizing damage,suggesting that it might be important in enhancing endoscope reprocessing procedures.
基金Funded by the Major Special Projects of Technological Innovation of Hubei Province(No.2017ACA168)the Open Fund Project of Sanya Science and Education Innovation Park of Wuhan University of Technology(No.2021KF0012)the Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120091)。
文摘To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug loading.By advanced spray drying,attapulgite was transformed into microspheres,refining its drug release characteristics.Various parameters were examined,achieving optimal particle size and morphology at 25%solid content,2.5%dispersant,and 3% binder.Attapulgite microspheres demonstrated exceptional encapsulation efficiency,exceeding 95% for doxorubicin hydrochloride,highlighting their versatility in drug delivery.FTIR and XRD were used to predict changes in material properties after spray drying.Notably,cytotoxicity tests confirmed the high biocompatibility of attapulgite microspheres,devoid of cell death induction.Attapulgite microsphere loaded with doxorubicin enable sustained drug release and maintain killing ability against tumor cells.This study confirms the viability of spray dried attapulgite microspheres for efficient drug loading and delivery and provides insights for innovative drug delivery systems that utilize the unique properties of attapulgite to advance therapeutics.
基金support from APC LLC,Ankeny,IA,USA,is greatly appreciated.
文摘Background Feeding spray dried plasma(SDP)to weanling pigs improves growth,but there is a lack of research on how SDP impacts oxidative stress and inflammatory response in lactating sows,and performance of their piglets after weaning.Therefore,an experiment was conducted to test the hypothesis that sows fed a diet with SDP in late gestation and lactation have improved reproductive performance and reduced inflammation compared with sows fed no SDP.The second hypothesis was that pigs weaned from sows fed 0.5%SDP in lactation have reduced diarrhea incidence and improved growth performance during the initial 14 d of the nursery period regardless of dietary SDP.Results The percent of low vitality or starved pigs during lactation was less(P<0.05)from sows fed 0.5%dietary SDP compared with sows fed the diet without SDP.Dietary SDP did not influence oxidative stress markers in the plasma of sows,but serum cytokines increased(P<0.05)in sows fed the diet with 0.5%SDP compared with sows fed the diet without SDP.Pigs weaned from young sows fed no SDP or from mature sows fed 0 or 0.5%SDP had a greater gain to feed ratio when fed a phase 1 diet containing 6%SDP compared with pigs fed a diet without SDP,but the gain to feed ratio of pigs weaned from young sows fed 0.5%dietary SDP was not affected by dietary SDP in phase 1(interaction,P<0.05).Regardless of sow treatment,pigs fed a phase 1 diet with 6%SDP had greater(P<0.05)growth performance than pigs fed a phase 1 diet without SDP,and pigs fed the phase 1 diet with 6%SDP had reduced(P<0.05)diarrhea incidence in phase 1.Conclusions Feeding 0.5%dietary SDP to sows may reduce the number of mummified pigs and increase pig vitality during lactation,but adding 0.5%SDP to sow diets during lactation did not improve post-weaning performance of pigs fed a starter diet with 6%SDP.
基金financially supported by the King Mongkut’s University of Technology North Bangkok(KMUTNB),Thailand(No.KMUTNB-63-KNOW-039)the Electricity Generating Authority of Thailand(No.64-N201000-11-IO.SS03N3008589)the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(No.B13F660125).
文摘This study examines how ball milling parameters,specifically rotational speeds(20,40,and 60 r/min)in dry and wet condi-tions,affect the development of mullite/5wt%nano-fly ash coatings on AISI 410 steel,focusing on their impact on feedstock powders and plasma-sprayed coatings.Optimized milling parameters at 60 r/min under wet conditions yielded high-quality feedstock powders with a particle size of 14μm and limited size distribution.Coatings produced from wet-milled powders demonstrated a higher deposition effi-ciency(35%)due to their smaller,uniformly distributed particles,which enhanced melting during the spraying process.These coatings also exhibited significantly lower porosity(7.9%),resulting in denser structures with superior mechanical properties,including a hardness of HV_(1)647,fracture toughness of 1.41 MPa·m^(0.5),and a smoother surface finish with a roughness(R_(a))of 6.1μm.Residual stress analysis showed that wet-milled coatings had higher residual stresses,reaching up to 165.95 MPa,compared to dry-milled coatings.This increase is attributed to finer particle sizes and rapid thermal cycling during deposition,which intensified tensile stresses within the coating.These results highlight the importance of optimizing milling parameters to enhance coating performance and process efficiency.
基金Supported by Shandong Province Major Agricultural Technologies Collaborative Promotion Project(SDNYXTTG-2024-04)National Key Laboratory for Quality Control of Chinese Medicinal Materials and Decoction Pieces Project(2024GSMPA-KL16)Weifang Municipal Science and Technology Bureau Project(2021GX031).
文摘[Objectives]To establish a high-performance liquid chromatography(HPLC)method for the simultaneous determination of forsythin,baicalin,and chlorogenic acid in a traditional Chinese medicine spray disinfectant.[Methods]The chromatographic separation was performed on a GL Sciences(19H0044724)-C_(18)column(4.6 mm×250 mm,5μm)with a mobile phase of acetonitrile-0.05%formic acid solution at a flow rate of 1 mL/min.The injection volume was 10μL,detection wavelength was set at 280 nm,and column temperature was maintained at 25℃.[Results]The linear ranges of forsythin,baicalin,and chlorogenic acid were 10.5-52.5,20.6-103,and 14.2-71μg/mL,respectively,with good linear relationships between concentration and peak area(R^(2)=0.9999).The relative standard deviations(RSD s)for precision and repeatability tests were all≤1.0%.The average recoveries were 98.51%,98.48%,and 97.71%for the three components,with RSD s of 0.96%,0.97%,and 0.73%,respectively.[Conclusions]This method demonstrates strong specificity,high precision,excellent accuracy,and simplicity of operation,making it suitable for the simultaneous quantification of forsythin,baicalin,and chlorogenic acid in traditional Chinese medicine spray disinfectants.It provides a reliable basis for quality control and practical applications in animal breeding environments.
基金supported by the National Natural Science Foundation of China(Nos.U23B6009 and 12272050)。
文摘Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.This paper presents a high-fidelity numerical study of liquidatomization and spray combustion under high-pressure conditions,emphasizing the effects of pres-sure oscillations on the flow evolution and combustion dynamics.The theoretical framework isbased on the three-dimensional conservation equations for multiphase flows and turbulent combus-tion.The numerical solution is achieved using a coupling method of volume-of-fluid and Lagran-gian particle tracking.The Zhuang-Kadota-Sutton(ZKS)high-pressure evaporation model andthe eddy breakup-Arrhenius combustion model are employed.Simulations are conducted for amodel combustion chamber with impinging-jet injectors using liquid oxygen and kerosene as pro-pellants.Both conditions with and without inlet and outlet pressure oscillations are considered.Thefindings reveal that pressure oscillations amplify flow fluctuations and can be characterized usingkey physical parameters such as droplet evaporation,chemical reaction,and chamber pressure.The spectral analysis uncovers the axial variations of the dominant and secondary frequenciesand their amplitudes in terms of the characteristic physical quantities.This research helps establisha methodology for exploring the coupling effect of liquid atomization and spray combustion.It alsoprovides practical insights into their responses to pressure oscillations during the occurrence ofcombustion instability.This information can be used to enhance the design and operation ofliquid-fueled propulsion engines.
基金supported by the Baoding City Self-Financed Fund Project(Project No.2241ZF339).
文摘Objective:This study investigates the preventive and therapeutic effects of medical radiation protection spray(Bergmann)compared to triethanolamine cream in patients undergoing radiotherapy following breast cancer surgery.Methods:Ninety patients with breast cancer who received postoperative radiotherapy between July 2018 and July 2021 were randomly divided into the Bergmann treatment(experimental)group and the triethanolamine cream treatment(control)group,with 45 patients in each group.Radiodermatitis severity was assessed using the RTOG radiodermatitis grading standards.Results:The radiation dose required to develop grade I radiodermatitis was significantly higher in the experimental group compared to the control group,at(36.13±1.17 Gy)and(25.38±0.63 Gy),respectively.At a radiation dose of 30 Gy,the proportion of grade I radiodermatitis cases in the experimental group was significantly lower than in the control group(P=0.002).At radiation doses of 40 Gy and 50 Gy,the proportion of grade II radiodermatitis cases in the experimental group was also significantly lower than in the control group(P<0.001).No cases of grade III or higher radiodermatitis were observed in the experimental group,while three cases of grade III radiodermatitis occurred in the control group,although the difference was not statistically significant.No patients in the experimental group discontinued treatment due to radiodermatitis or mucosal reactions,whereas two patients in the control group interrupted treatment due to these reactions but eventually completed therapy.Conclusion:Bergmann spray effectively prevents radiodermatitis in patients undergoing radiotherapy after breast cancer surgery and is more effective than triethanolamine cream in treating skin lesions.Its ease of use improves the quality of life for patients undergoing radiotherapy and ensures successful treatment completion.Bergmann is suitable for clinical promotion and application.
基金supported by the National Key Research and Development Program of China(2022YFB3504501)the National Natural Science Foundation of China(52274355)。
文摘This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions.It proposes the idea of introducing spray pyrolysis technology into the rare earth extraction and separation processes.This paper briefly describes the development history of chloride spray pyrolysis technology,focusing on the research status and application progress of rare earth chloride solution and magnesium chloride solution spray pyrolysis technology,as well as spray pyrolysis equipment.The paper also analyzes the challenges and technical intricacies associated with applying spray pyrolysis technology to chloride solutions in the rare earth extraction and separation processes.Additionally,it explores future trends and proposes strategies to facilitate the full recycling of acids and bases,streamline the process flow,and enhance the prospects for green and low-carbon rare earth metallurgy.
文摘The advancement in endoscopic technology and techniques has increased its use in the diagnosis and treatment of gastrointestinal diseases.Reprocessing of reusable endoscopes remains a challenge.Inadequate reprocessing leads to bacterial contamination of the endoscope,a significant cause of endoscope-related infections.To thoroughly address the complexities of cleaning a flexible endo-scope,various cleaning methods have been devised and tested across different studies.This letter evaluates one such method,spray flushing for flexible gastro-scopes,developed and tested in a randomized controlled trial by Du et al.Based on the post-processing test results for this method,Du et al conclude that there is improved cleaning efficacy and reduced damage compared to manual brush cleaning.The validity and reliability of the results could be further enhanced by carefully considering the study design and a few underlying concepts that contribute to the reprocessing quality of different types of endoscopes.
文摘Delay tolerant wireless sensor networks(DTWSN)is a class of wireless network that finds its deployment in those application scenarios which demand for high packet delivery ratio while maintaining minimal overhead in order to prolong network lifetime;owing to resource-constrained nature of sensors.The fundamental requirement of any network is routing a packet from its source to destination.Performance of a routing algorithm depends on the number of network parameters utilized by that routing protocol.In the recent years,various routing protocol has been developed for the delay tolerant networks(DTN).A routing protocol known as spray and wait(SnW)is one of the most widely used routing algorithms for DTN.In this paper,we study the SnW routing protocol and propose a modified version of it referred to as Pentago SnW which is based on pentagonal number series.Comparison to binary SnW shows promising results through simulation using real-life scenarios of cars and pedestrians randomly moving on a map.
基金supported by the National Natural Science Foundation of China(Nos.U2341202,12402333).
文摘Dual Synthetic Jets (DSJ) can directly affect the development of spray through the complex vortex structure. The mechanism of flow control on spray and its thermal management application are studied by combining experiment and simulation. The spray characteristics under different injection angles are studied, and the results show that the angle should be controlled in the range of 45°–60°, so that sufficient momentum transfer can be obtained, and meanwhile spray impingement area narrowing can be avoided. The spray characteristics under flow control of DSJ with different Reynolds numbers are studied, and the results show that Reynolds number should be controlled in the range of 2859–3574, so that strong particle streamwise acceleration and wall film disturbing can be achieved. In addition, the DSJ kinetic energy is utilized more efficiently. On the basis of previous research, this paper proposes a novel active heat pipe based on spray controlled by DSJ. The space occupancy has been reduced by more than 60%. Even in a sealed state, the active heat pipe is able to cool a hot surface with heat flux of 22.2 kW/m^(2) from 111℃ to 57℃ only in 20 s. The noise of DSJ is reduced from 85 dB to 60 dB, which is expected to promote the practical application of DSJ in thermal management.
基金supported by Guangdong Natural Science Foundation(No.2024A1515011287)Guangdong Academy of Sciences Project(No.2021GDASYL-20210102002)+2 种基金GDAS’Project of Science and Technology Development(Nos.2022GDASZH-2022010103 and 2022GDASZH-2022010202-04)GuangDong Province Key-Area R&D Program(No.2020B0101340004)the Ministry of Science and Higher Education of the Russian Federation within the framework of the“World-class Science Center”program:Advanced Digital Technologies(No.075-15-2022-312 from 20 April 2022).
文摘Cold spray(CS)has been attracting an increasing interest due to low heat input,which avoids grain growth and high thermal stress.This feature is beneficial for high damping Mn-Cu alloy through limiting oxidation and formation of hot cracks.However,high dislocation density formed because of extensive plastic deformation,pores,and cracks result in the low damping capacity in the as-deposited Mn-Cu alloy.New strategy was introduced for improving damping capacity in cold sprayed Mn-20Cu-5Ni-2Fe(M2052 at%)alloy with different particle sizes(below 25μm and between 15 and 53μm).The 15-53μm powder has high yield strength and plastic deformation resistance,which leads to a large number of defects and non-bonded interface between powders due to insufficient plastic deformation.Ageing treatment at 420℃leads to spinodal decomposition of the fcc-austenite,and the formation of Mn-rich matrix and Cu-rich nanoscale network structure is found.Under the same ageing conditions,the spinodal decomposition level of the fcc-austenite in the CS M2052 alloy with the particles of 15-53μm is higher than that with the particles of<25μm,which results from the difference in the grain size.As a result,the damping capacity in the CS M2052 samples with particle size of 15-53μm is higher compared with the CS M2052 sample with particle size of<25μm.There is a significant increase in the damping capacity in the CS M2052 samples after HIP treatment,which can effectively reduce the internal defects and improve the bonding properties between powders.
基金supported by the National Natural Science Foundation of China(No.52404354).
文摘Pitting corrosion poses a significant challenge to 9Cr18 high-carbon chromium bearing steel in chloride-rich environments,severely compromising its structural integrity.The study systematically investigates the pitting behaviour of 9Cr18 bearing steel under salt spray conditions,focusing on the progressive evolution of surface morphology and cross-sectional characteristics of pits on finished bearings.Scanning electron microscopy,energy-dispersive spectroscopy and X-ray diffraction were employed to examine the surface morphology,elemental composition and phase structure of corrosion products over varying salt spray exposure durations.The results show that 9Cr18 steel exhibits localized pitting with“volcanic crater”-like pits in the early stage of salt spray corrosion.After 48 h,pitting develops into a“multi-point”pattern,marking the initial transition toward uniform corrosion.Until 240 h,corrosion products completely cover the surface,indicating the complete transformation from localized pitting to uniform corrosion.The high carbon and chromium content in 9Cr18 steel promotes carbide precipitation and uneven distribution in the matrix.Cr-depleted regions near the carbide/matrix interface serve as preferential sites for pitting initiation.The low effective utilization of chromium reduces the overall corrosion resistance of 9Cr18.
基金supported by the National Natural Science Foundation of China (No.52175315)the Shenzhen Science and Technology Program,China (No.KQTD20200820113110016)the Hunan Provincial Postgraduate Research Innovation Program,China (No.CX20220404)。
文摘The corrosion resistance of aluminum(Al)cable-copper(Cu)terminal joints fabricated by magnetic pulse crimping(MPC)and hydraulic clamp crimping(HCC)was compared.Performance degradation was evaluated by mechanical and electrical properties.Additionally,corrosion behavior was analyzed by electrochemical testing.Microscopic characterization was performed by scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Results show that the tensile strength of the corroded joints is reduced.However,due to the advantages of high-speed forming and contact tightness unique to MPC,the contact resistance of the corroded joints still maintains excellent.Electrochemical tests demonstrate that the MPC joints have higher corrosion potentials and smaller corrosion currents,providing better corrosion resistance.The formation of a primary battery between Al and Cu at the lap joint leads to the formation of severer corrosion pits.
基金supported by the National Natural Science Foundation of China(No.52122407)the Science and Technology Innovation Program of Hunan Province(No.2022RC3048)。
文摘Nickel-rich cathode materials have received widespread attention due to their high energy density.However,the poor rate capability and inferior cycle stability seriously hinder their large-scale application.The traditional co-precipitation method for preparing them has a long process and easily arises agglomeration leading to inhomogeneous element distribution.Here,a novel precursor containing Li element was prepared by ultrafast spray pyrolysis(SP)in 3–5 s.Then the precursor was used to synthesize pristine LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90)and 1%Mg modified LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90-Mg1).This method gets rid of mixing Li/Mg source and the precursor prepared by common co-precipitation,thus could achieve homogeneous lithiation and Mg2+doping.The cell parameter c is expanded,and the cation disorder is reduced after Mg2+doping.Furthermore,the harmful H2-H3 phase transition in NCM90-Mg1 is also well suppressed.As a result,the obtained NCM90-Mg1 shows better electrochemical performance than NCM90.Within 2.8–4.3 V(25℃),the specific discharge capacity of NCM90-Mg1 at 5 C is as high as 169.1m Ah/g,and an outstanding capacity retention of 70.0%(10.0%higher than NCM90)can be obtained after400 cycles at 0.5 C.At 45℃,a capacity retention of 81.9%after 100 cycles at 1 C is recorded for NCM90-Mg1.Moreover,the NCM90-Mg1 also exhibits superior cycle stability when cycled at high cut-off voltage(4.5 V,25℃),possessing the capacity retention of 79.2%after 200 cycles at 1 C.Therefore,SP can be proposed as a powerful method for the preparation of multi-element materials for next-generation high energy density LIBs.
文摘Large interfacial strains in particles are crucial for promoting bonding in cold spraying(CS),initiated either by adiabatic shear instability(ASI)due to softening prevailing over strain hardening or by hydrostatic plasticity,which is claimed to promote bonding even without ASI.A thorough microstructural analysis is vital to fully understand the bonding mechanisms at play during microparticle impacts and throughout the CS process.In this study,the HEA CoCrFeMnNi,known for its relatively high strain hardening and resistance to softening,was selected to investigate the microstructure characteristics and bonding mech-anisms in CS.This study used characterization techniques covering a range of length scales,including electron channeling contrast imaging(ECCI),electron backscatter diffraction(EBSD),and high-resolution transmission microscopy(HR-TEM),to explore the microstructure characteristics of bonding and overall structure development of CoCrFeMnNi microparticles after impact in CS.HR-TEM lamellae were prepared using focused ion beam milling.Additionally,the effects of deformation field variables on microstructure development were determined through finite element modeling(FEM)of microparticle impacts.The ECCI,EBSD,and HR-TEM analyses revealed an interplay between dislocation-driven processes and twinning,leading to the development of four distinct deformation microstructures.Significant grain refinement occurs at the interface through continuous dynamic recrystallization(CDRX)due to high strain and temperature rise from adiabatic deformation,signs of softening,and ASI.Near the interface,a necklace-like structure of refined grains forms around grain boundaries,along with elongated grains,resulting from the coexistence of dynamic recovery and discontinuous dynamic recrystallization(DDRX)due to lower temperature rise and strain.Towards the particle or substrate interior,concurrent twinning and dislocation-mediated mechanisms refine the structure,forming straight,curved,and intersected twins.At the top of the particles,only deformed grains with a low dislocation density are observed.Our results showed that DRX induces microstructure softening in highly strained interface areas,facilitating atomic bonding in CoCrFeMnNi.HR-TEM investigation confirms the formation of atomic bonds between particles and substrate,with a gradual change in crystal lattice orientation from the particle to the substrate and the occurrence of some misfit dislocations and vacancies at the interface.Finally,the findings of this research suggest that softening and ASI,even in materials resistant to softening,are required to establish bonding in CS.
基金supported by the Provincial or Ministerial Level Project.
文摘The spray characteristics of different regions downstream of swirl cups play a critical role in cold start and re-ignition of gas turbines.The spray measurements were performed at the fuel pressures of 0.5,0.8,1.0,1.5,and 2.0 MPa and the fuel temperatures of-23,-13,-3,7,17 and 27℃,respectively.The droplet size,droplet velocity,droplet number,and instantaneous spatial spray image of sprays from an aviation kerosene Jet-A were measured using a two-component phase Doppler particle analyzer and a digital off-axis holography system.As the fuel pressure and temperature increase,the Sauter Mean Diameter(SMD)and spray non-uniformity of the Spray Shear Layer(SSL)gradually decrease.As the fuel pressure increases,the SMD and spray non-uniformity of the Central Toroidal Recirculation Zone(CTRZ)gradually decrease,and the slopes of these curves both decrease.As the fuel pressure increases,the SMD and spray nonuniformity of the CTRZ rapidly decrease at the fuel temperature of23℃,while slightly decrease at the fuel temperature of 27℃.The droplets in the CTRZ come from 3 different sources:simplex nozzle,venturi,and outside the CTRZ.As the fuel pressure increases,the proportion of droplets recirculated from outside the CTRZ decreases.This study proposed the concept of the“pressure critical point”for the swirl cups.As the fuel temperature decreases,the proportion of droplets recirculated from outside the CTRZ increases below the critical pressure,while decreases above the critical pressure.In addition,through the models of liquid film formation and breakup on the curved cylindrical wall,a semi-theoretical model was established to predict the SMD of SSL for swirl cups.The prediction uncertainty of this model is less than 6%for all 14 conditions in this paper.
基金the Natural Science Foundation of Jiangsu Province(No.BK20220588)the Initial Scientific Research Fund of Yangzhou University(No.137012553)and the Public Welfare Technology Research Program of Zhejiang Province(Nos.LGG19E060001 and LGG 21E090001)。
文摘The reduction of oxygen consumption is a key factor to improve the energy density of underwater Stirling engine.A series of fundamental experiments are carried out to elucidate the spray characteristics of soybean oil/2,5-dimethylfuran(DMF)blended fuel in an underwater Stirling engine.Spray characteristics such as spray penetration,spray angle,spray area,and light intensity level under low injection and ambient pressures are obtained using image post-processing method.The results show that the effects of injection pressure,ambient pressure,and nozzle diameter on the transient spray characteristics of underwater Stirling engine are similar to those of diesel engine.However,in the steady spray process,the injection pressure has little effect on spray near angle,and the spray far angle increases with the increase of the injection pressure.Compared with the spray far angle at injection pressure of 3 MPa,the spray far angle at 5 MPa and 7 MPa increased by 11.38%and 18.14%respectively.The addition of DMF can obviously improve the atomization of soybean oil/DMF blended fuel.The spray angle of blended fuel in transient process increases with the increase of the DMF concentration.The spray near angle has exceeded that of diesel(46.21°)when the DMF volume fraction exceeds 25%.The spray far angle is equivalent to that of diesel when the DMF volume fraction reaches 75%.Moreover,the spray with gas ejection no longer keeps conical,the droplet diameter distribution is more dispersed,and the droplet diameter is smaller.
基金the financial support from the following funding agency and projects:Science Foundation Ireland Frontiers for the Future Project(No.20/FFP-P/8815)National Natural Science Foundation of China(Nos.51875471,52001078,and 52061135101)+2 种基金China Scholarship Council-Trinity College Dublin Joint Scholarship Programme(No.201906460020)International Cooperation Project of Guangdong Province(No.2021A0505030052)Alexander von Humboldt Foundation.
文摘Cold spray,as a solid-state additive manufacturing process,has been attracting increasing attention from both scientific and industrial communities.However,cold-sprayed deposits generally have unfavorable mechanical properties in their as-fabricated state compared to conventionally manufactured and fusion-based additive-manufactured counterparts due to the inherent microstructural defects in the deposits(e.g.,porosity and incomplete interparticle bonding).This downside reduces its competitiveness and limits its wide applications as an additive manufacturing process.In the past years,many strengthening technologies have been developed or introduced to adjust the microstructure and improve the mechanical properties of cold-sprayed deposits.The term“strengthening”in this work specifically refers to improving the mechanical strength,particularly the tensile strength of the cold-sprayed bulk deposits.According to the stage that the strengthening technologies are used in the cold spray process,they can be classified into three categories:pre-process(e.g.,powder heat treatment),in-process(e.g.,powder heating,in-situ micro-forging,laser-assisted cold spray),and post-process(e.g.,post heat treatment,hot isostatic pressing,hot rolling,friction stir processing).Therefore,a comprehensive review of these strengthening technolo-gies is conducted to illuminate the possible correlations between the strengthening mechanisms and the resultant deposit microstructures and mechanical properties.This review paper aims to help researchers and engineers well understand the different strengthening methods and provide guidance for the cold spray community to develop new strengthening strategies for future high-quality mass production.
