Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generat...Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.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
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 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
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 low-temperature spray drying technology was developed to process instant berry powder with high efficiency and higher anthocyanin retention.The maltodextrin,whey protein and inulin were selected as additives for i...The low-temperature spray drying technology was developed to process instant berry powder with high efficiency and higher anthocyanin retention.The maltodextrin,whey protein and inulin were selected as additives for instant properties formation in berry powder.The effects of inlet air temperature(40℃–80℃),vacuum degree(0.02–0.06 MPa)and additive amount on the physicochemical properties of berry powder were analyzed through solubility,anthocyanin retention and powder yield,based on moisture content and microstructure.The findings indicated that adding maltodextrin to berry enhanced the powder yield and instant solubility.Whey protein,as an additive,provided effective protection for the anthocyanins of berry powder,and the addition less than 10 g·100^(-1) g improved the powder yield.Inulin,as an additive,reduced moisture content of berry powder,which was conducive to the higher anthocyanin retention and solubility.Technique for order preference by similarity to ideal solution(TOPSIS)analysis was conducted to optimize the spray drying parameters for anthocyanin protection and solubility.The addition of 100%maltodextrin enhanced anthocyanin protection and solubility,while maintaining the desired moisture content and powder yield.This approach was used to evaluate the comprehensive quality of berry powder.This research can provide technical guidance for producing berry powder under low-temperature spray drying.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
Modifications in fuel spray characteristics fundamentally influence fuel–air mixing dynamics in diesel engines,thereby significantly affecting combustion performance and emission profiles.This study explores the oper...Modifications in fuel spray characteristics fundamentally influence fuel–air mixing dynamics in diesel engines,thereby significantly affecting combustion performance and emission profiles.This study explores the operational behavior of RP-5 aviation kerosene/diesel blended fuels in marine diesel engines.A spray visualization platform based on Mie scattering technology was developed to comparatively analyze the spray characteristics,ignition behavior,and soot emissions of RP-5 aviation kerosene,conventional-35#diesel,and their blends at varying mixing ratios(D100H0,D90H10,D70H30,D50H50,D30H70,D0H100).The findings demonstrate that,under constant injection pressure,aviation kerosene combustion results in a more uniform temperature field,characterized by lower core flame temperatures,broader high-temperature regions,and reduced soot concentrations with spatially homogeneous distribution and no pronounced peaks.In terms of spray dynamics,increasing the proportion of aviation kerosene leads to a marked widening of the spray cone angle.Meanwhile,spray penetration length exhibits a non-monotonic trend—initially decreasing and subsequently increasing—as the kerosene blending ratio rises.展开更多
Magnesium(Mg)alloys are ideal candidates for automotive applications due to their high strength to weight ratio,castability,recyclability etc.,however,they lack corrosion and oxidation resistance.Solid-state depositio...Magnesium(Mg)alloys are ideal candidates for automotive applications due to their high strength to weight ratio,castability,recyclability etc.,however,they lack corrosion and oxidation resistance.Solid-state deposition techniques,such as cold spray,have been demonstrated to enhance their corrosion resistance as it relies on the severe plastic deformation of powder particles upon impact with the substrate to form a metallurgical bond with the substrate and within the coating.At cold sprayed interfaces,a heterogeneous microstructure is formed that includes some porosity,oxides and intermetallics which can significantly affect coating performance.Thus,establishing a direct correlation between the interface microstructure and its properties can aid in designing optimal cold spray parameters.In this study,we investigated the microstructure and mechanical properties of a zinc(Zn)coating deposited on a high pressure die cast(HPDC)AZ91 Mg substrate via high resolution scanning transmission electron microscopy,in situ micro-tensile testing,and finite element method(FEM)modeling.Micro-tensile pillars fabricated using the plasma focused ion beam(PFIB)successfully isolates the coating-substrate interface within the gauge length.The average bond strength of Zn-Mg interface was determined to be∼140 MPa with failure occurring partially at the interface and mostly into the coatings.A detailed microstructural characterization revealed evidence of a strong metallurgical bonding at the Zn-Mg interface and formation of the C14 MgZn_(2)laves phase interlayer resulting in a mixed mode of fracture during the micro-tensile experiments.FEM modeling reveals the stress distribution along the interfaces and suggests that a MgZn_(2)layer thickness between 200–400 nm is optimum to increase the bond strength and minimize the triaxiality.Such a site-specific interfacial analysis with correlative computational modeling provides crucial insight into the overall performance of cold spray interfaces.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
As renewable fuel,alcohol could be added into the fuel with low volatility to trigger flash boiling,which has been considered an effective method to facilitate the atomization of fuel sprays and reduce emissions.Howev...As renewable fuel,alcohol could be added into the fuel with low volatility to trigger flash boiling,which has been considered an effective method to facilitate the atomization of fuel sprays and reduce emissions.However,the competing relationship between volatility and high latent heat leads to a complex atomization process,making it more challenging to investigate the effects of alcohol addition on plume interaction and vortex evolution.To illustrate the influences of alcohol addition on the fuel atomization performance,spray macroscopic and microscopic characteristics under various operating conditions were obtained using Diffuse Backlight Illumination(DBI)and Phase Doppler Anemometry(PDA)methods,and dynamic collapse ratio were used to characterize morphologies variations.The addition of alcohol facilitates the nucleation process,and its effects are affected by heavy components,attributed to the dependence of the energy barrier of nucleation on fuel properties.Parameters were proposed based on the energy barrier,supplementing Rp to predict the plume expansion of fuels with unknown properties.The dynamic collapse ratio is able to reflect the plume evaporation efficiency,plume interaction and vortex movement direction.This study aims to shed more light on the flashing characteristics of multi-component fuels with distinct properties,facilitating the efficient utilization of renewable fuels.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
基金financial support from the Nuclear Energy Science&Technology and Human Resource Development Project of the Japan Atomic Energy Agency/Collaborative Laboratories for Advanced Decommissioning Science(No.R04I034)The author Ruicong Xu appreciates the scholarship(financial support)from the China Scholarship Council(CSC,No.202106380073).
文摘Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.
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 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.
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 National Natural Science Foundation of China(32072352)。
文摘The low-temperature spray drying technology was developed to process instant berry powder with high efficiency and higher anthocyanin retention.The maltodextrin,whey protein and inulin were selected as additives for instant properties formation in berry powder.The effects of inlet air temperature(40℃–80℃),vacuum degree(0.02–0.06 MPa)and additive amount on the physicochemical properties of berry powder were analyzed through solubility,anthocyanin retention and powder yield,based on moisture content and microstructure.The findings indicated that adding maltodextrin to berry enhanced the powder yield and instant solubility.Whey protein,as an additive,provided effective protection for the anthocyanins of berry powder,and the addition less than 10 g·100^(-1) g improved the powder yield.Inulin,as an additive,reduced moisture content of berry powder,which was conducive to the higher anthocyanin retention and solubility.Technique for order preference by similarity to ideal solution(TOPSIS)analysis was conducted to optimize the spray drying parameters for anthocyanin protection and solubility.The addition of 100%maltodextrin enhanced anthocyanin protection and solubility,while maintaining the desired moisture content and powder yield.This approach was used to evaluate the comprehensive quality of berry powder.This research can provide technical guidance for producing berry powder under low-temperature spray drying.
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 Innovation Research Project for the training of high-level scientific and technological talents(Technical expert talents)of the Armed Police Force ZZKY20222415Research and Innovation Team in Marine Propulsion Technology,China Coast Guard Academy.
文摘Modifications in fuel spray characteristics fundamentally influence fuel–air mixing dynamics in diesel engines,thereby significantly affecting combustion performance and emission profiles.This study explores the operational behavior of RP-5 aviation kerosene/diesel blended fuels in marine diesel engines.A spray visualization platform based on Mie scattering technology was developed to comparatively analyze the spray characteristics,ignition behavior,and soot emissions of RP-5 aviation kerosene,conventional-35#diesel,and their blends at varying mixing ratios(D100H0,D90H10,D70H30,D50H50,D30H70,D0H100).The findings demonstrate that,under constant injection pressure,aviation kerosene combustion results in a more uniform temperature field,characterized by lower core flame temperatures,broader high-temperature regions,and reduced soot concentrations with spatially homogeneous distribution and no pronounced peaks.In terms of spray dynamics,increasing the proportion of aviation kerosene leads to a marked widening of the spray cone angle.Meanwhile,spray penetration length exhibits a non-monotonic trend—initially decreasing and subsequently increasing—as the kerosene blending ratio rises.
基金the support of the U.S. Department of Energy Vehicle Technologies Office
文摘Magnesium(Mg)alloys are ideal candidates for automotive applications due to their high strength to weight ratio,castability,recyclability etc.,however,they lack corrosion and oxidation resistance.Solid-state deposition techniques,such as cold spray,have been demonstrated to enhance their corrosion resistance as it relies on the severe plastic deformation of powder particles upon impact with the substrate to form a metallurgical bond with the substrate and within the coating.At cold sprayed interfaces,a heterogeneous microstructure is formed that includes some porosity,oxides and intermetallics which can significantly affect coating performance.Thus,establishing a direct correlation between the interface microstructure and its properties can aid in designing optimal cold spray parameters.In this study,we investigated the microstructure and mechanical properties of a zinc(Zn)coating deposited on a high pressure die cast(HPDC)AZ91 Mg substrate via high resolution scanning transmission electron microscopy,in situ micro-tensile testing,and finite element method(FEM)modeling.Micro-tensile pillars fabricated using the plasma focused ion beam(PFIB)successfully isolates the coating-substrate interface within the gauge length.The average bond strength of Zn-Mg interface was determined to be∼140 MPa with failure occurring partially at the interface and mostly into the coatings.A detailed microstructural characterization revealed evidence of a strong metallurgical bonding at the Zn-Mg interface and formation of the C14 MgZn_(2)laves phase interlayer resulting in a mixed mode of fracture during the micro-tensile experiments.FEM modeling reveals the stress distribution along the interfaces and suggests that a MgZn_(2)layer thickness between 200–400 nm is optimum to increase the bond strength and minimize the triaxiality.Such a site-specific interfacial analysis with correlative computational modeling provides crucial insight into the overall performance of cold spray interfaces.
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financially supported by the National Natural Science Foundation of China(52104183)Natural Science Fundation of Chongqing(cstc2021jcyj-bshX0091)+2 种基金Graduate Research and Innovation Foundation of Chongqing(CYB22024)the Fundamental Research Funds for the Central Universities(2021CDJQY-031)the Cheung Kong Scholars and Innovation Team Development Program(IRT17R112).
文摘As renewable fuel,alcohol could be added into the fuel with low volatility to trigger flash boiling,which has been considered an effective method to facilitate the atomization of fuel sprays and reduce emissions.However,the competing relationship between volatility and high latent heat leads to a complex atomization process,making it more challenging to investigate the effects of alcohol addition on plume interaction and vortex evolution.To illustrate the influences of alcohol addition on the fuel atomization performance,spray macroscopic and microscopic characteristics under various operating conditions were obtained using Diffuse Backlight Illumination(DBI)and Phase Doppler Anemometry(PDA)methods,and dynamic collapse ratio were used to characterize morphologies variations.The addition of alcohol facilitates the nucleation process,and its effects are affected by heavy components,attributed to the dependence of the energy barrier of nucleation on fuel properties.Parameters were proposed based on the energy barrier,supplementing Rp to predict the plume expansion of fuels with unknown properties.The dynamic collapse ratio is able to reflect the plume evaporation efficiency,plume interaction and vortex movement direction.This study aims to shed more light on the flashing characteristics of multi-component fuels with distinct properties,facilitating the efficient utilization of renewable fuels.
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.
