Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal diseases.During the last few years,the incidence rate of perforations in colonoscopi...Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal diseases.During the last few years,the incidence rate of perforations in colonoscopic procedures has increased,especially in therapeutic colonoscopies.The recent advancements in endoscopic techniques and gastrointestinal tumoral resection procedures such as endoscopic mucosal resection,endoscopic full-thickness resection,and endoscopic submucosal dissection(ESD)could be a risk factor for this increased risk.The incidence rate of mortality of serious colonoscopic perforations is 7.1%.The management plan for these perforations starts with conservative treatment in mild cases,endoscopic closure,and surgical management in severe cases.Recently,endoluminal vacuum therapy was found to be effective in the management of colorectal perforations and this has been reported in multiple case reports.This editorial provides an overview of the current guidelines for the management of iatrogenic colorectal perforations.These insights are from the perspectives of endoscopists and gastroenterologists.We also present a management algorithm based on the guidelines of the European Society of Gastrointestinal Endoscopy,the American Gastroenterological Association,and the World Society of Emergency Surgery.We also discussed in brief the use of endoluminal vacuum therapy in colorectal perforations.展开更多
In recent years,there has been a growing global demand for carbon neutrality and energy efficiency,which are expected to become long-term trends.In the field of architecture,an effective approach to achieve this is to...In recent years,there has been a growing global demand for carbon neutrality and energy efficiency,which are expected to become long-term trends.In the field of architecture,an effective approach to achieve this is to reduce heat loss in buildings.Vacuum insulation panels(VIPs),a type of high-performance insulation material,have been increasingly utilised in the construction industry and have played an increa-singly important role as their performance and manufacturing processes continue to improve.This paper provides a review of the factors affecting the thermal conductivity of VIPs and presents a detailed overview of the research progress on core materials,barrier films,and getters.The current research status of VIPs is summarised,including their thermal conductivity,service life,and thermal bridging effects,as well as their applications in the field of architecture.This review aims to provide a comprehensive understanding for relevant practitioners on the factors influencing the thermal conductivity of VIPs,and based on which,measures can be taken to produce VIPs with lower thermal conductivity and longer service life.展开更多
High-temperature phase change materials(PCMs)have attracted significant attention in the field of thermal energy storage due to their ability to store and release large amounts of heat within a small temperature fluct...High-temperature phase change materials(PCMs)have attracted significant attention in the field of thermal energy storage due to their ability to store and release large amounts of heat within a small temperature fluctuation range.However,their practical application is limited due to problems such as leakage,corrosion,and volume changes at high temperatures.Recent research has shown that macroencapsulation technology holds promise in addressing these issues.This paper focuses on the macroencapsulation technology of high-temperature PCMs,starting with a review of the classification and development history of high-temperature macroencapsulatd PCMs.Four major encapsulation strategies,including electroplating method,solid/liquid filling method,sacrificial material method,and powder compaction into sphere method,are then summarized.The methods for effectively addressing issues such as corrosion,leakage,supercooling,and phase separation in PCMs are analyzed,along with approaches for improving the heat transfer performance,mechanical strength,and thermal cycling stability of macrocapsules.Subsequently,the structure and packing arrangement optimization of macrocapsules in thermal storage systems is discussed in detail.Finally,after comparing the performance of various encapsulation strategies and summarizing existing issues,the current technical challenges,improvement methods,and future development directions are proposed.More attention should be given to utilizing AI technology and reinforcement learning to reveal the multiphysics-coupled heat and mass transfer mechanisms in macrocapsule applications,as well as to optimize material selection and encapsulation parameters,thereby enhancing the overall efficiency of thermal storage systems.展开更多
Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate...Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate than aluminum,and its greater complexity poses challenges to existing recycling processes.Although vacuum distillation can be used to recycle Mg alloy scrap,this requires optimizing and maximizing metal recirculation,but there has been no thermodynamic analysis of this process.In this study,the feasibility and controllability of separating inclusions and 23 metal impurities were evaluated,and their distribution and removal limits were quantified.Thermodynamic analyses and experimental results showed that inclusions and impurity metals of separation coefficient lgβ_(i)≤-5,including Cu,Fe,Co,and Ni below 0.001 ppm,could be removed from the matrix.All Zn entered the recycled Mg,while impurities with-1<lgβ_(i)<-5 such as Li,Ca,and Mn severely affected the purity of the recycled Mg during the later stage of distillation.Therefore,an optimization strategy for vacuum distillation recycling:lower temperatures and higher system pressures for Zn separation in the early stage,and the early termination of the recovery process in the later stage or a continuous supply of raw melt can also prevent contamination during recycling.The alloying elements Al and Zn in Mg alloy scrap can be further recovered and purified by vacuum distillation when economically feasible,to maximize the recycling of metal resources.展开更多
Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industr...Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industries.The global production of primary magnesium has reached approximately 1.2 million tons per year,with anticipated diversification in future applications and significant market demand.Nevertheless,approximately 80%of the world’s primary magnesium is still manufactured through the Pidgeon process,grappling with formidable issues including high energy consumption,massive carbon emission,significant resource depletion,and environmental pollution.The implementation of the relative vacuum method shows potential in breaking through technological challenges in the Pidgeon process,facilitating clean,low-carbon continuous magnesium smelting.This paper begins by introducing the principles of the relative vacuum method.Subsequently,it elucidates various innovative process routes,including relative vacuum ferrosilicon reduction,aluminum thermal reduction co-production of spinel,and aluminum thermal reduction co-production of calcium aluminate.Finally,and thermodynamic foundations of the relative vacuum,a quantitative analysis of the material,energy flows,carbon emission,and production cost for several new processes is conducted,comparing and analyzing them against the Pidgeon process.The study findings reveal that,with identical raw materials,the relative vacuum silicon thermal reduction process significantly decreases raw material consumption,energy consumption,and carbon dioxide emissions by 15.86%,30.89%,and 26.27%,respectively,compared to the Pidgeon process.The relative vacuum process,using magnesite as the raw material and aluminum as the reducing agent,has the lowest magnesium-to-feed ratio,at only 3.385.Additionally,its energy consumption and carbon dioxide emissions are the lowest,at 1.817 tce/t Mg and 7.782 t CO_(2)/t Mg,respectively.The energy consumption and carbon emissions of the relative vacuum magnesium smelting process co-producing calcium aluminate(12CaO·7Al_(2)O_(3),3CaO·Al_(2)O_(3),and CaO·Al_(2)O_(3))are highly correlated with the consumption of dolomite in the raw materials.When the reduction temperature is around 1473.15 K,the critical volume fraction of magnesium vapor for different processes varies within the range of 5%–40%.Production cost analysis shows that the relative vacuum primary magnesium smelting process has significant economic benefits.This paper offers essential data support and theoretical guidance for achieving energy efficiency,carbon reduction in magnesium smelting,and the industrial adoption of innovative processes.展开更多
High-purity indium finds extensive application in the aerospace,electronics,medical,energy,and national defense sectors.Its purity and impurity contents significantly influence its performance in these applications.Hi...High-purity indium finds extensive application in the aerospace,electronics,medical,energy,and national defense sectors.Its purity and impurity contents significantly influence its performance in these applications.High-purity indium was prepared by combining zone refining with vacuum distillation.Results show that the average removal efficiency of impurity Sb can approach 95%,while the removal efficiency of impurities Sn and Bi can reach over 95%,and the removal efficiency of Si,Fe,Ni,and Pb can reach over 85%.Ultimately,the amount of Sn and Sb impurities is reduced to 2.0 and 4.1μg/kg,respectively,and that of most impurities,including Fe,Ni,Pb,and Bi,is reduced to levels below the instrumental detection limit.The average impurity removal efficiency is 90.9%,and the indium purity reaches 7N9.展开更多
Polycrystalline diamond compact(PDC)cutters and carbon steel were brazed by AgCuInTi filler metal under vacuum condition.The effects of brazing temperature on the wettability of base metal and shear strength of joints...Polycrystalline diamond compact(PDC)cutters and carbon steel were brazed by AgCuInTi filler metal under vacuum condition.The effects of brazing temperature on the wettability of base metal and shear strength of joints were investigated.Besides,the joint's interface microstructure,composition,and phases were analyzed.Results show that the AgCuInTi filler metal exerts a good wetting effect to the surface of cemented carbide and steel.With the increase in brazing temperature,the wetting angle decreases and the spreading area increases.The suitable temperature for vacuum brazing of PDC cutters is 770℃,and the maximum shear strength is 228 MPa at this temperature.展开更多
BACKGROUND A case study of multiple distinct levels of skipped thoracolumbar spine infection was reported in which 13 successful vacuum sealing drainage(VSD)surgeries were treated.CASE SUMMARY The patient underwent a ...BACKGROUND A case study of multiple distinct levels of skipped thoracolumbar spine infection was reported in which 13 successful vacuum sealing drainage(VSD)surgeries were treated.CASE SUMMARY The patient underwent a total of 13 procedures within our medical facility,including five performed under local anesthesia and eight performed under general anesthesia.The source of the ailment was ultimately identified as Enterobacter cloacae.After the last procedure,the patient's symptoms were alleviated,and the recovery process was satisfactory.Three months post-operation,the Japanese Orthopaedic Association scores had improved to 100%.Imageological examination revealed a satisfactory position of internal fixation,and the abnormal signals in the vertebral body and intervertebral space had been eliminated when compared to the pre-operative results.CONCLUSION The study demonstrates that the extreme lateral approach debridement combined with multiple VSD operations is a secure and successful method of treatment for recurrent spinal infection,providing an alternative to traditional surgery.展开更多
We introduce our state-of-the art of“vacuum consistent electrochemistry”to an investigation of the interfaces between oxides and ionic liquid(IL).Pulsed laser deposition(PLD)has been one of the powerful and sophisti...We introduce our state-of-the art of“vacuum consistent electrochemistry”to an investigation of the interfaces between oxides and ionic liquid(IL).Pulsed laser deposition(PLD)has been one of the powerful and sophisticated techniques to realize nanoscale preparation of high-quality epitaxial oxide thin films.On the other hand,electrochemistry is a simple,very sensitive,and non-destructive analysis technique for solid-liquid interfaces.To ensure the reproducibility in experiment of the interfaces of such epitaxial oxide films,as well as bulk oxide single-crystals,with IL,we employ a home-built PLD-electrochemical(EC)system with IL as an electrolyte.The system allows one to perform all-in-vacuum experiments during the preparation of well-defined oxide electrode surfaces to their electrochemical analyses.The topics include electrochemical evaluations of the oxide’s own properties,such as carrier density and relative permittivity,and the interfacial properties of oxides in contact with IL,such as flat band potential and electric double layer(EDL)capacitance,ending with future perspectives in all-solid-state electrochemistry.展开更多
AZ31/Al/Ta composites were prepared using the vacuum hot compression bonding(VHCB)method.The effect of hot compressing temperature on the interface microstructure evolution,phase constitution,and shear strength at the...AZ31/Al/Ta composites were prepared using the vacuum hot compression bonding(VHCB)method.The effect of hot compressing temperature on the interface microstructure evolution,phase constitution,and shear strength at the interface was investigated.Moreover,the interface bonding mechanisms of the AZ31/Al/Ta composites during the VHCB process were explored.The results demonstrate that as the VHCB temperature increases,the phase composition of the interface between Mg and Al changes from the Mg-Al brittle intermetallic compounds(Al_(12)Mg_(17)and Al_(3)Mg_(2))to the Al-Mg solid solution.Meanwhile,the width of the Al/Ta interface diffusion layer at 450℃increases compared to that at 400℃.The shear strengths are 24 and 46 MPa at 400 and 450℃,respectively.The interfacial bonding mechanism of AZ31/Al/Ta composites involves the coexistence of diffusion and mechanical meshing.Avoiding the formation of brittle phases at the interface can significantly improve interfacial bonding strength.展开更多
Magnesium plays an important role in biomedicine,new energy vehicles,aerospace and other fields because of its excellent physical and chemical properties.China is a major source of magnesium worldwide,with the output ...Magnesium plays an important role in biomedicine,new energy vehicles,aerospace and other fields because of its excellent physical and chemical properties.China is a major source of magnesium worldwide,with the output of primary magnesium accounting for>80%of the world’s total annual output.The smelting process represented by the Pidgeon process plays the leading role in China because of its simple process flow and equipment and the flexibility of the production scale.However,the Pidgeon process always has the problems of low utilization of reduction heat,a short lifetime of the reduction tank,a high cost of the reduction furnace,and a discontinuous production process.Therefore,how to produce magnesium in a clean,efficient and continuous manner has been the focus of industry development research.In this work,from the perspective of the preparation of magnesium by thermal reduction,the production of high-purity magnesium,and the recycling of waste magnesium alloys,the research status of magnesium preparation by direct vacuum and relative vacuum processes was reviewed,including the reduction mechanism,migration and condensation patterns and production efficiency of magnesium.The effects of the reducing agent,reduction temperature,holding time and other factors on the preparation of magnesium were emphasized.Finally,by comparing the production processes of magnesium by direct vacuum and relative vacuum methods,the advantages and disadvantages of the two methods for the preparation of magnesium were mainly discussed,and the future development of magnesium was proposed.展开更多
Many azo compounds and their intermediates are toxic and have been linked to various health issues,representing a growing global problem.Molecular engineering for selective encapsulation of azobenzene compounds is cri...Many azo compounds and their intermediates are toxic and have been linked to various health issues,representing a growing global problem.Molecular engineering for selective encapsulation of azobenzene compounds is critical,given their significant use in smart materials and prevalence as environmental micropollutants released from the food and dye industries.However,the current host molecules catering to azobenzene compounds are mainly limited to cyclodextrins,pillar[n]arenes and cucurbit[n]urils,demonstrating a moderate affinity.This report describes that a novel 3,3'-bipyridinium-based cyclophane was capable of encapsulating anionic azobenzene compounds in water with high binding affinity and pH stability through electrostatic attraction-enhanced mechanism,surpassing the extensively reported supramolecular systems.1D&2D NMR experiments,UV-vis spectrum,X-ray crystallography and computational modeling were carried out to understand the host-vip complexation.It's worth noting that the tetracationic cyclophane exhibited good selective and anti-interference encapsulation properties in binary,ternary and seawater systems.Furthermore,upon UV/white light irradiation,the reversible conversion between(E)-4,4'-azobisbenzoate and(Z)-4,4'-azobisbenzoate triggers the dissociation/recomplexation of the host-vip complex within 3 min.This reversible photo-switchable(E)-disodium 4,4'-azobisbenzoateBPy-Box^(4+)supramolecular system holds promise for designing novel materials for extraction/release of azo compounds and other small smart materials.展开更多
Vacuum pressure vessels are one of the critical components in the aerospace field,and understanding the mechanical behavior feature is particularly important for safe operation.Therefore,it is meaningful to obtain the...Vacuum pressure vessels are one of the critical components in the aerospace field,and understanding the mechanical behavior feature is particularly important for safe operation.Therefore,it is meaningful to obtain the stress and strain distributions in the key positions of the vacuum tank,which can contribute to the safe performance assessment,operation efficiency,and fault analysis.Hence,this paper provides the distribution characteristics and variation rules of stress and tank strain of vacuum under different internal and external pressures through the elastic theoretical analysis and iteration method.The quasi-distributed fiber Bragg grating(FBG)sensors and the layout on the vacuum pressure vessel have thus been designed to monitor the whole vacuum extraction and loss process under three different loading conditions.Data analysis based on the theoretical results and monitoring information has further been conducted to validate the effectiveness of the proposed monitoring method for possible leakage defects.Research results indicate that the continuously monitoring data can quite sensitively and accurately characterize the microstrain variation features of the vacuum tank at different vacuum stages,and the loading-induced vibration effect should be carefully considered during the data interpretation.The study can provide scientific support for the vacuum loss state monitoring and safe performance assessment of the vacuum pressure vessels.展开更多
Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the...Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the treatment of gastrointestinal and respiratory issues along with increasing the platelet count in patients suffering from dengue.In this review paper,the nutritional composition and bioactive compounds of guava leaves,including proteins,vitamins,minerals,and polysaccharides,have been reviewed.The methods of extraction of bioactive compounds from guava leaves and their bioactivities,including antioxidant,anti-diabetic,and anti-cancer potential,have been explored.Further,encapsulation techniques for improving the transport of bioactive compounds and living cells into foods have been studied.The application of guava leaves in different food systems such as herbal tea,pork sausage,chocolates,jelly,meals for chickens,functional beverages,and as antibacterial agents in food preservatives has also been investigated.The findings of this review illustrated that the phytochemicals present in guava leaves showed excellent antimicrobial and antioxidant properties.Encapsulation appears to be a promising technique for improving the stability,bioavailability,and controlled release of bioactive chemicals extracted from guava leaves.Different methods for the encapsulation of bioactive compounds employed and applied in distinct food systems showed preservation of phytochemicals,improved bioactivities,and nutritional values.Overall,this review paper demonstrated how guava leaves,an abundant source of bioactive compounds,can be used as a multipurpose component to create functional foods,edible coatings,and active packaging to enhance the nutritional,antioxidant,and antimicrobial properties of various food systems that have qualities that promote health.展开更多
One of the issues of plasma technologies is the design of a high-performance plasma source.Due to its properties,a diffuse vacuum arc discharge may be one of the promising options.In this study,the dependence of the c...One of the issues of plasma technologies is the design of a high-performance plasma source.Due to its properties,a diffuse vacuum arc discharge may be one of the promising options.In this study,the dependence of the charge composition of a diffuse vacuum arc plasma with a hot cathode on the value of the external axial magnetic field and discharge voltage was investigated.The study was conducted with a thermionic gadolinium(Gd)cathode.Monitoring the charge composition was done by analyzing the emission spectra of the plasma.Steady states of arc discharge were obtained for a range of parameters.The arc currents were 30 and 40 A,the arc voltage was up to 29 V and the external magnetic field was varied from 0 to 20 mT.It was found that in the presence of the eternal magnetic field the defining factor of the charge composition was the arc voltage.Moreover,for a fixed arc voltage,an increase in magnitude causes an increase in intensities of all atomic and ionic plasma components(Gd,Gd+,Gd++).The potential causes of this effect were discussed.It was established that in an axial magnetic field it is possible to implement discharge modes with predominance of single-charge ions by increasing the magnitude of the external magnetic field.Potentially,these discharge modes will be of use for the implementation of plasma methods for reprocessing spent nuclear fuel.展开更多
Encapsulation and protection of hesperidin(HES)in mung bean protein isolate(MPI)-dextran(DX)conjugatestabilized nanoemulsions(MDC NEs)were investigated in this study.The degree of grafting of MDC prepared by a dry-hea...Encapsulation and protection of hesperidin(HES)in mung bean protein isolate(MPI)-dextran(DX)conjugatestabilized nanoemulsions(MDC NEs)were investigated in this study.The degree of grafting of MDC prepared by a dry-heating method reached 39.70%±0.01% under the optimal conditions of MPI/DX mass ratio 1:2.3,reaction temperature 58.8℃,and reaction time 4 d.Moreover,the analyses of Fourier infrared spectroscopy,intrinsic fluorescence spectroscopy,surface hydrophobicity,and thermal stability further confirmed the covalent grafting of dextran onto MPI molecules.When encapsulated in MDC NEs at 80 MPa for three times by highpressure homogenization,the encapsulation efficiency and loading capacity of HES were 63.62%±0.01%and 0.40±0.00 g/g,respectively.The encapsulated HES exhibited higher antioxidant activity and stronger light and storage stability than the free HES.Additionally,the incorporation of HES inhibited the formation of lipid peroxides in the nanoemulsions.The findings suggest that glycosylation combined with high-pressure homogenization is an effective strategy for enhancing the stability of MPI-based emulsions and improving their encapsulation of HES.This study provides a promising approach for the development of innovative food and beverage products based on MPI emulsions or new materials for encapsulating fat-soluble bioactive compounds.展开更多
The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with B...The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with Bi/Si ratio in low-melting glass was investigated.In addition,the relationships between laser power,low-melting glass solder with different Bi/Si ratios and laser sealing shear strength were revealed.The results show that a decrease in the Bi/Si ratio can cause a contraction of the glass network of the low-melting glass,leading to an increase of its characteristic temperature and a decrease of its coefficient of thermal expansion.During laser sealing,the copper ions in the low-melting glass play an endothermic role.A change in the Bi/Si ratio will affect the valence state transition of the copper ions in the low-melting glass.The absorbance of the low-melting glass does not follow the expected correlation with the Bi/Si ratio,but shows a linear correlation with the content of divalent copper ions.The greater the concentration of divalent copper ions,the greater the absorbance of the low-melting glass,and the lower the laser power required for laser sealing.The shear strength of the low melting glass solder after laser sealing was tested,and it was found that the maximum shear strength of Z1 glass sample was the highest up to 2.67 MPa.展开更多
Cryopreservation is a fundamental technology in biomedical research,regenerative medicine,and tissue engineering,enabling the long-term storage of cells,tissues,and organs.However,its effectiveness is limited by chall...Cryopreservation is a fundamental technology in biomedical research,regenerative medicine,and tissue engineering,enabling the long-term storage of cells,tissues,and organs.However,its effectiveness is limited by challenges such as intracellular ice formation,cryoprotectant toxicity,and reduced post-thaw viability.This review explores the crucial role of encapsulation in enhancing cryopreservation efficiency,with a focus on recent advances in materials science,bioengineering,and cryobiology.Emerging technologies,such as nanotechnology and stimuli-responsive polymers,are transforming encapsulation strategies.Innovations such as microfluidic systems offer precise control over cooling rates and cryoprotectant distribution,thereby mitigating conventional limitations.The review also addresses current obstacles related to scaling up encapsulation processes and ensuring the long-term biocompatibility and stability of preserved specimens.By synthesizing recent findings,this work provides a comprehensive resource for researchers and clinicians seeking to enhance biopreservation techniques and their applications in contemporary medicine and biotechnology.Finally,the review identifies critical knowledge gaps that must be addressed to improve the efficacy of cryopreservation strategies and advance their clinical translation.展开更多
Magnesium alloys,regarded as the most promising structural materials for lightweight applications,have gained enhanced strength and heat resistance through the addition of rare earth elements,leading to their widespre...Magnesium alloys,regarded as the most promising structural materials for lightweight applications,have gained enhanced strength and heat resistance through the addition of rare earth elements,leading to their widespread use in aerospace and defense industries.However,with the growing volume of end-of-life components and inherently low production yields,the efficient recycling of rare earth-containing magnesium alloys has become increasingly critical.This study explores the separation and enrichment behavior of magnesium and neodymium during the vacuum recycling of rare earth magnesium alloys,utilizing gas-liquid phase theory and phase diagram computational methods.Both theoretical analyses and experimental results indicate that the separation process in the Mg-Nd system—whether by vacuum distillation or gasification—follows a consistent phase transformation sequence:Mg_(41)Nd_(5)→Mg_(3)Nd→MgNd→Nd.Two distinct neodymium-rich morphologies were observed:a loose porous structure and a dense,compact form.Notably,vacuum gasification of ZM6 rare earth magnesium alloy resulted in a neodymium concentration of 82.91 wt.%in the solid residue.The process demonstrated high direct recovery efficiency,rapid separation kinetics,and zero secondary waste generation—establishing it as a green and highly efficient recycling approach for magnesium alloy scrap.These findings provide fundamental theoretical and practical support for the recycling of Nd-containing magnesium alloys and contribute to the sustainable utilization of secondary rare earth resources.展开更多
Nervonic acid(NA) is a long-chain monounsaturated fatty acid with significant potential for neural fiber repair.In this study,a mixed fatty acid methyl ester was synthesized as the raw material through saponification ...Nervonic acid(NA) is a long-chain monounsaturated fatty acid with significant potential for neural fiber repair.In this study,a mixed fatty acid methyl ester was synthesized as the raw material through saponification of Acer truncatum Bunge seed oil.Based on the differences in boiling points and relative volatilities of various components,a four-stage vacuum batch distillation process was employed to enrich the nervonic acid methyl ester(NAME).The effect of distillation process parameters on enrichment efficiency was investigated,including distillation temperature,operating pressure,and reflux ratio.The purity of NAME achieved as 91.20% under optimal conditions and the corresponding yield was 48.91%.To further increase the purity,a low-temperature crystallization process was adopted and a final purity of NAME was obtained as 97.56%.Simulation of the above four-stage batch distillation was conducted using Aspen Plus software,and a continuous distillation processes was further simulated to establish a theoretical basis for future industrial-scale production.The results of experiments and simulation demonstrate that the integrated process of vacuum distillation and low-temperature crystallization exhibits remarkable separation performances,providing robust guidance for the production of high-purity NA.展开更多
文摘Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal diseases.During the last few years,the incidence rate of perforations in colonoscopic procedures has increased,especially in therapeutic colonoscopies.The recent advancements in endoscopic techniques and gastrointestinal tumoral resection procedures such as endoscopic mucosal resection,endoscopic full-thickness resection,and endoscopic submucosal dissection(ESD)could be a risk factor for this increased risk.The incidence rate of mortality of serious colonoscopic perforations is 7.1%.The management plan for these perforations starts with conservative treatment in mild cases,endoscopic closure,and surgical management in severe cases.Recently,endoluminal vacuum therapy was found to be effective in the management of colorectal perforations and this has been reported in multiple case reports.This editorial provides an overview of the current guidelines for the management of iatrogenic colorectal perforations.These insights are from the perspectives of endoscopists and gastroenterologists.We also present a management algorithm based on the guidelines of the European Society of Gastrointestinal Endoscopy,the American Gastroenterological Association,and the World Society of Emergency Surgery.We also discussed in brief the use of endoluminal vacuum therapy in colorectal perforations.
文摘In recent years,there has been a growing global demand for carbon neutrality and energy efficiency,which are expected to become long-term trends.In the field of architecture,an effective approach to achieve this is to reduce heat loss in buildings.Vacuum insulation panels(VIPs),a type of high-performance insulation material,have been increasingly utilised in the construction industry and have played an increa-singly important role as their performance and manufacturing processes continue to improve.This paper provides a review of the factors affecting the thermal conductivity of VIPs and presents a detailed overview of the research progress on core materials,barrier films,and getters.The current research status of VIPs is summarised,including their thermal conductivity,service life,and thermal bridging effects,as well as their applications in the field of architecture.This review aims to provide a comprehensive understanding for relevant practitioners on the factors influencing the thermal conductivity of VIPs,and based on which,measures can be taken to produce VIPs with lower thermal conductivity and longer service life.
基金supported by the National Natural Science Foundation of China(Grant No.51976092)。
文摘High-temperature phase change materials(PCMs)have attracted significant attention in the field of thermal energy storage due to their ability to store and release large amounts of heat within a small temperature fluctuation range.However,their practical application is limited due to problems such as leakage,corrosion,and volume changes at high temperatures.Recent research has shown that macroencapsulation technology holds promise in addressing these issues.This paper focuses on the macroencapsulation technology of high-temperature PCMs,starting with a review of the classification and development history of high-temperature macroencapsulatd PCMs.Four major encapsulation strategies,including electroplating method,solid/liquid filling method,sacrificial material method,and powder compaction into sphere method,are then summarized.The methods for effectively addressing issues such as corrosion,leakage,supercooling,and phase separation in PCMs are analyzed,along with approaches for improving the heat transfer performance,mechanical strength,and thermal cycling stability of macrocapsules.Subsequently,the structure and packing arrangement optimization of macrocapsules in thermal storage systems is discussed in detail.Finally,after comparing the performance of various encapsulation strategies and summarizing existing issues,the current technical challenges,improvement methods,and future development directions are proposed.More attention should be given to utilizing AI technology and reinforcement learning to reveal the multiphysics-coupled heat and mass transfer mechanisms in macrocapsule applications,as well as to optimize material selection and encapsulation parameters,thereby enhancing the overall efficiency of thermal storage systems.
文摘Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate than aluminum,and its greater complexity poses challenges to existing recycling processes.Although vacuum distillation can be used to recycle Mg alloy scrap,this requires optimizing and maximizing metal recirculation,but there has been no thermodynamic analysis of this process.In this study,the feasibility and controllability of separating inclusions and 23 metal impurities were evaluated,and their distribution and removal limits were quantified.Thermodynamic analyses and experimental results showed that inclusions and impurity metals of separation coefficient lgβ_(i)≤-5,including Cu,Fe,Co,and Ni below 0.001 ppm,could be removed from the matrix.All Zn entered the recycled Mg,while impurities with-1<lgβ_(i)<-5 such as Li,Ca,and Mn severely affected the purity of the recycled Mg during the later stage of distillation.Therefore,an optimization strategy for vacuum distillation recycling:lower temperatures and higher system pressures for Zn separation in the early stage,and the early termination of the recovery process in the later stage or a continuous supply of raw melt can also prevent contamination during recycling.The alloying elements Al and Zn in Mg alloy scrap can be further recovered and purified by vacuum distillation when economically feasible,to maximize the recycling of metal resources.
基金supported by the China Postdoctoral Science Foundation(No.2023T160088)the Youth Fund of the National Natural Science Foundation of China(No.52304324).
文摘Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industries.The global production of primary magnesium has reached approximately 1.2 million tons per year,with anticipated diversification in future applications and significant market demand.Nevertheless,approximately 80%of the world’s primary magnesium is still manufactured through the Pidgeon process,grappling with formidable issues including high energy consumption,massive carbon emission,significant resource depletion,and environmental pollution.The implementation of the relative vacuum method shows potential in breaking through technological challenges in the Pidgeon process,facilitating clean,low-carbon continuous magnesium smelting.This paper begins by introducing the principles of the relative vacuum method.Subsequently,it elucidates various innovative process routes,including relative vacuum ferrosilicon reduction,aluminum thermal reduction co-production of spinel,and aluminum thermal reduction co-production of calcium aluminate.Finally,and thermodynamic foundations of the relative vacuum,a quantitative analysis of the material,energy flows,carbon emission,and production cost for several new processes is conducted,comparing and analyzing them against the Pidgeon process.The study findings reveal that,with identical raw materials,the relative vacuum silicon thermal reduction process significantly decreases raw material consumption,energy consumption,and carbon dioxide emissions by 15.86%,30.89%,and 26.27%,respectively,compared to the Pidgeon process.The relative vacuum process,using magnesite as the raw material and aluminum as the reducing agent,has the lowest magnesium-to-feed ratio,at only 3.385.Additionally,its energy consumption and carbon dioxide emissions are the lowest,at 1.817 tce/t Mg and 7.782 t CO_(2)/t Mg,respectively.The energy consumption and carbon emissions of the relative vacuum magnesium smelting process co-producing calcium aluminate(12CaO·7Al_(2)O_(3),3CaO·Al_(2)O_(3),and CaO·Al_(2)O_(3))are highly correlated with the consumption of dolomite in the raw materials.When the reduction temperature is around 1473.15 K,the critical volume fraction of magnesium vapor for different processes varies within the range of 5%–40%.Production cost analysis shows that the relative vacuum primary magnesium smelting process has significant economic benefits.This paper offers essential data support and theoretical guidance for achieving energy efficiency,carbon reduction in magnesium smelting,and the industrial adoption of innovative processes.
基金National Key Research and Development Program of China(2023YFC2907904)National Natural Science Foundation of China(52374364)。
文摘High-purity indium finds extensive application in the aerospace,electronics,medical,energy,and national defense sectors.Its purity and impurity contents significantly influence its performance in these applications.High-purity indium was prepared by combining zone refining with vacuum distillation.Results show that the average removal efficiency of impurity Sb can approach 95%,while the removal efficiency of impurities Sn and Bi can reach over 95%,and the removal efficiency of Si,Fe,Ni,and Pb can reach over 85%.Ultimately,the amount of Sn and Sb impurities is reduced to 2.0 and 4.1μg/kg,respectively,and that of most impurities,including Fe,Ni,Pb,and Bi,is reduced to levels below the instrumental detection limit.The average impurity removal efficiency is 90.9%,and the indium purity reaches 7N9.
基金National Natural Science Foundation of China(52075551,52271045,51975469)Supported by State Key Laboratory of Advanced Welding and Joining(AWJ-22M09)+2 种基金Supported by State Key Laboratory of Advanced Brazing Filler Metals and Technology(SKLABFMT201904)Key Research and Development Program of Shaanxi Province(2022GY-224)Innovative Talent Recommendation Program(Youth Science and Technology New Star Project)of Shaanxi Province(2020 KJX X-045)。
文摘Polycrystalline diamond compact(PDC)cutters and carbon steel were brazed by AgCuInTi filler metal under vacuum condition.The effects of brazing temperature on the wettability of base metal and shear strength of joints were investigated.Besides,the joint's interface microstructure,composition,and phases were analyzed.Results show that the AgCuInTi filler metal exerts a good wetting effect to the surface of cemented carbide and steel.With the increase in brazing temperature,the wetting angle decreases and the spreading area increases.The suitable temperature for vacuum brazing of PDC cutters is 770℃,and the maximum shear strength is 228 MPa at this temperature.
基金Supported by Natural Science Foundation of Shandong Province,No.ZR2023MH331.
文摘BACKGROUND A case study of multiple distinct levels of skipped thoracolumbar spine infection was reported in which 13 successful vacuum sealing drainage(VSD)surgeries were treated.CASE SUMMARY The patient underwent a total of 13 procedures within our medical facility,including five performed under local anesthesia and eight performed under general anesthesia.The source of the ailment was ultimately identified as Enterobacter cloacae.After the last procedure,the patient's symptoms were alleviated,and the recovery process was satisfactory.Three months post-operation,the Japanese Orthopaedic Association scores had improved to 100%.Imageological examination revealed a satisfactory position of internal fixation,and the abnormal signals in the vertebral body and intervertebral space had been eliminated when compared to the pre-operative results.CONCLUSION The study demonstrates that the extreme lateral approach debridement combined with multiple VSD operations is a secure and successful method of treatment for recurrent spinal infection,providing an alternative to traditional surgery.
文摘We introduce our state-of-the art of“vacuum consistent electrochemistry”to an investigation of the interfaces between oxides and ionic liquid(IL).Pulsed laser deposition(PLD)has been one of the powerful and sophisticated techniques to realize nanoscale preparation of high-quality epitaxial oxide thin films.On the other hand,electrochemistry is a simple,very sensitive,and non-destructive analysis technique for solid-liquid interfaces.To ensure the reproducibility in experiment of the interfaces of such epitaxial oxide films,as well as bulk oxide single-crystals,with IL,we employ a home-built PLD-electrochemical(EC)system with IL as an electrolyte.The system allows one to perform all-in-vacuum experiments during the preparation of well-defined oxide electrode surfaces to their electrochemical analyses.The topics include electrochemical evaluations of the oxide’s own properties,such as carrier density and relative permittivity,and the interfacial properties of oxides in contact with IL,such as flat band potential and electric double layer(EDL)capacitance,ending with future perspectives in all-solid-state electrochemistry.
基金National Natural Science Foundation of China(52275308,52301146)Fundamental Research Funds for the Central Universities(2023JG007)Supported by Shi Changxu Innovation Center for Advanced Materials(SCXKFJJ202207)。
文摘AZ31/Al/Ta composites were prepared using the vacuum hot compression bonding(VHCB)method.The effect of hot compressing temperature on the interface microstructure evolution,phase constitution,and shear strength at the interface was investigated.Moreover,the interface bonding mechanisms of the AZ31/Al/Ta composites during the VHCB process were explored.The results demonstrate that as the VHCB temperature increases,the phase composition of the interface between Mg and Al changes from the Mg-Al brittle intermetallic compounds(Al_(12)Mg_(17)and Al_(3)Mg_(2))to the Al-Mg solid solution.Meanwhile,the width of the Al/Ta interface diffusion layer at 450℃increases compared to that at 400℃.The shear strengths are 24 and 46 MPa at 400 and 450℃,respectively.The interfacial bonding mechanism of AZ31/Al/Ta composites involves the coexistence of diffusion and mechanical meshing.Avoiding the formation of brittle phases at the interface can significantly improve interfacial bonding strength.
基金the combined funding from the National Natural Science Foundation of China(U1908225,U1702253,U1508217)。
文摘Magnesium plays an important role in biomedicine,new energy vehicles,aerospace and other fields because of its excellent physical and chemical properties.China is a major source of magnesium worldwide,with the output of primary magnesium accounting for>80%of the world’s total annual output.The smelting process represented by the Pidgeon process plays the leading role in China because of its simple process flow and equipment and the flexibility of the production scale.However,the Pidgeon process always has the problems of low utilization of reduction heat,a short lifetime of the reduction tank,a high cost of the reduction furnace,and a discontinuous production process.Therefore,how to produce magnesium in a clean,efficient and continuous manner has been the focus of industry development research.In this work,from the perspective of the preparation of magnesium by thermal reduction,the production of high-purity magnesium,and the recycling of waste magnesium alloys,the research status of magnesium preparation by direct vacuum and relative vacuum processes was reviewed,including the reduction mechanism,migration and condensation patterns and production efficiency of magnesium.The effects of the reducing agent,reduction temperature,holding time and other factors on the preparation of magnesium were emphasized.Finally,by comparing the production processes of magnesium by direct vacuum and relative vacuum methods,the advantages and disadvantages of the two methods for the preparation of magnesium were mainly discussed,and the future development of magnesium was proposed.
基金support by the National Natural Science Foundation of China(No.52473225)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515110262)。
文摘Many azo compounds and their intermediates are toxic and have been linked to various health issues,representing a growing global problem.Molecular engineering for selective encapsulation of azobenzene compounds is critical,given their significant use in smart materials and prevalence as environmental micropollutants released from the food and dye industries.However,the current host molecules catering to azobenzene compounds are mainly limited to cyclodextrins,pillar[n]arenes and cucurbit[n]urils,demonstrating a moderate affinity.This report describes that a novel 3,3'-bipyridinium-based cyclophane was capable of encapsulating anionic azobenzene compounds in water with high binding affinity and pH stability through electrostatic attraction-enhanced mechanism,surpassing the extensively reported supramolecular systems.1D&2D NMR experiments,UV-vis spectrum,X-ray crystallography and computational modeling were carried out to understand the host-vip complexation.It's worth noting that the tetracationic cyclophane exhibited good selective and anti-interference encapsulation properties in binary,ternary and seawater systems.Furthermore,upon UV/white light irradiation,the reversible conversion between(E)-4,4'-azobisbenzoate and(Z)-4,4'-azobisbenzoate triggers the dissociation/recomplexation of the host-vip complex within 3 min.This reversible photo-switchable(E)-disodium 4,4'-azobisbenzoateBPy-Box^(4+)supramolecular system holds promise for designing novel materials for extraction/release of azo compounds and other small smart materials.
基金supported by the Provincial Scientific Projects of Gansu(22YF7GA182)Innovation Foundation of Provincial Education Department of Gansu(2024B-005)Fundamental Research Funds for the Central Universities(No.lzujbky-2024-05).
文摘Vacuum pressure vessels are one of the critical components in the aerospace field,and understanding the mechanical behavior feature is particularly important for safe operation.Therefore,it is meaningful to obtain the stress and strain distributions in the key positions of the vacuum tank,which can contribute to the safe performance assessment,operation efficiency,and fault analysis.Hence,this paper provides the distribution characteristics and variation rules of stress and tank strain of vacuum under different internal and external pressures through the elastic theoretical analysis and iteration method.The quasi-distributed fiber Bragg grating(FBG)sensors and the layout on the vacuum pressure vessel have thus been designed to monitor the whole vacuum extraction and loss process under three different loading conditions.Data analysis based on the theoretical results and monitoring information has further been conducted to validate the effectiveness of the proposed monitoring method for possible leakage defects.Research results indicate that the continuously monitoring data can quite sensitively and accurately characterize the microstrain variation features of the vacuum tank at different vacuum stages,and the loading-induced vibration effect should be carefully considered during the data interpretation.The study can provide scientific support for the vacuum loss state monitoring and safe performance assessment of the vacuum pressure vessels.
文摘Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the treatment of gastrointestinal and respiratory issues along with increasing the platelet count in patients suffering from dengue.In this review paper,the nutritional composition and bioactive compounds of guava leaves,including proteins,vitamins,minerals,and polysaccharides,have been reviewed.The methods of extraction of bioactive compounds from guava leaves and their bioactivities,including antioxidant,anti-diabetic,and anti-cancer potential,have been explored.Further,encapsulation techniques for improving the transport of bioactive compounds and living cells into foods have been studied.The application of guava leaves in different food systems such as herbal tea,pork sausage,chocolates,jelly,meals for chickens,functional beverages,and as antibacterial agents in food preservatives has also been investigated.The findings of this review illustrated that the phytochemicals present in guava leaves showed excellent antimicrobial and antioxidant properties.Encapsulation appears to be a promising technique for improving the stability,bioavailability,and controlled release of bioactive chemicals extracted from guava leaves.Different methods for the encapsulation of bioactive compounds employed and applied in distinct food systems showed preservation of phytochemicals,improved bioactivities,and nutritional values.Overall,this review paper demonstrated how guava leaves,an abundant source of bioactive compounds,can be used as a multipurpose component to create functional foods,edible coatings,and active packaging to enhance the nutritional,antioxidant,and antimicrobial properties of various food systems that have qualities that promote health.
基金supported by the Russian Science Foundation(No.23-72-10073)。
文摘One of the issues of plasma technologies is the design of a high-performance plasma source.Due to its properties,a diffuse vacuum arc discharge may be one of the promising options.In this study,the dependence of the charge composition of a diffuse vacuum arc plasma with a hot cathode on the value of the external axial magnetic field and discharge voltage was investigated.The study was conducted with a thermionic gadolinium(Gd)cathode.Monitoring the charge composition was done by analyzing the emission spectra of the plasma.Steady states of arc discharge were obtained for a range of parameters.The arc currents were 30 and 40 A,the arc voltage was up to 29 V and the external magnetic field was varied from 0 to 20 mT.It was found that in the presence of the eternal magnetic field the defining factor of the charge composition was the arc voltage.Moreover,for a fixed arc voltage,an increase in magnitude causes an increase in intensities of all atomic and ionic plasma components(Gd,Gd+,Gd++).The potential causes of this effect were discussed.It was established that in an axial magnetic field it is possible to implement discharge modes with predominance of single-charge ions by increasing the magnitude of the external magnetic field.Potentially,these discharge modes will be of use for the implementation of plasma methods for reprocessing spent nuclear fuel.
基金financially supported by the National Natural Science Foundation of China(Grant No.32101981)the cooperation project between Ya’an city and Sichuan Agricultural University(23ZDF0003)。
文摘Encapsulation and protection of hesperidin(HES)in mung bean protein isolate(MPI)-dextran(DX)conjugatestabilized nanoemulsions(MDC NEs)were investigated in this study.The degree of grafting of MDC prepared by a dry-heating method reached 39.70%±0.01% under the optimal conditions of MPI/DX mass ratio 1:2.3,reaction temperature 58.8℃,and reaction time 4 d.Moreover,the analyses of Fourier infrared spectroscopy,intrinsic fluorescence spectroscopy,surface hydrophobicity,and thermal stability further confirmed the covalent grafting of dextran onto MPI molecules.When encapsulated in MDC NEs at 80 MPa for three times by highpressure homogenization,the encapsulation efficiency and loading capacity of HES were 63.62%±0.01%and 0.40±0.00 g/g,respectively.The encapsulated HES exhibited higher antioxidant activity and stronger light and storage stability than the free HES.Additionally,the incorporation of HES inhibited the formation of lipid peroxides in the nanoemulsions.The findings suggest that glycosylation combined with high-pressure homogenization is an effective strategy for enhancing the stability of MPI-based emulsions and improving their encapsulation of HES.This study provides a promising approach for the development of innovative food and beverage products based on MPI emulsions or new materials for encapsulating fat-soluble bioactive compounds.
基金Funded by the National Natural Science Foundation of China(No.52472012)Opening Project of State Silica-Based Materials Laboratory of Anhui Province(No.2022KF11)the Research and Development of Glass Powder for Laser Sealing and Its Sealing Technology(No.K24556)。
文摘The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with Bi/Si ratio in low-melting glass was investigated.In addition,the relationships between laser power,low-melting glass solder with different Bi/Si ratios and laser sealing shear strength were revealed.The results show that a decrease in the Bi/Si ratio can cause a contraction of the glass network of the low-melting glass,leading to an increase of its characteristic temperature and a decrease of its coefficient of thermal expansion.During laser sealing,the copper ions in the low-melting glass play an endothermic role.A change in the Bi/Si ratio will affect the valence state transition of the copper ions in the low-melting glass.The absorbance of the low-melting glass does not follow the expected correlation with the Bi/Si ratio,but shows a linear correlation with the content of divalent copper ions.The greater the concentration of divalent copper ions,the greater the absorbance of the low-melting glass,and the lower the laser power required for laser sealing.The shear strength of the low melting glass solder after laser sealing was tested,and it was found that the maximum shear strength of Z1 glass sample was the highest up to 2.67 MPa.
基金supported by the National Natural Science Foundation of China(82172114)the"Challenge and Response"project for key and common technology research of Hefei(GJ2022SH08).
文摘Cryopreservation is a fundamental technology in biomedical research,regenerative medicine,and tissue engineering,enabling the long-term storage of cells,tissues,and organs.However,its effectiveness is limited by challenges such as intracellular ice formation,cryoprotectant toxicity,and reduced post-thaw viability.This review explores the crucial role of encapsulation in enhancing cryopreservation efficiency,with a focus on recent advances in materials science,bioengineering,and cryobiology.Emerging technologies,such as nanotechnology and stimuli-responsive polymers,are transforming encapsulation strategies.Innovations such as microfluidic systems offer precise control over cooling rates and cryoprotectant distribution,thereby mitigating conventional limitations.The review also addresses current obstacles related to scaling up encapsulation processes and ensuring the long-term biocompatibility and stability of preserved specimens.By synthesizing recent findings,this work provides a comprehensive resource for researchers and clinicians seeking to enhance biopreservation techniques and their applications in contemporary medicine and biotechnology.Finally,the review identifies critical knowledge gaps that must be addressed to improve the efficacy of cryopreservation strategies and advance their clinical translation.
基金supported by the National Natural Science Foundation of China(No.92475108)Yunnan Province Nonferrous Metal Vacuum Metallurgy Top Team(No.202305AS350012).
文摘Magnesium alloys,regarded as the most promising structural materials for lightweight applications,have gained enhanced strength and heat resistance through the addition of rare earth elements,leading to their widespread use in aerospace and defense industries.However,with the growing volume of end-of-life components and inherently low production yields,the efficient recycling of rare earth-containing magnesium alloys has become increasingly critical.This study explores the separation and enrichment behavior of magnesium and neodymium during the vacuum recycling of rare earth magnesium alloys,utilizing gas-liquid phase theory and phase diagram computational methods.Both theoretical analyses and experimental results indicate that the separation process in the Mg-Nd system—whether by vacuum distillation or gasification—follows a consistent phase transformation sequence:Mg_(41)Nd_(5)→Mg_(3)Nd→MgNd→Nd.Two distinct neodymium-rich morphologies were observed:a loose porous structure and a dense,compact form.Notably,vacuum gasification of ZM6 rare earth magnesium alloy resulted in a neodymium concentration of 82.91 wt.%in the solid residue.The process demonstrated high direct recovery efficiency,rapid separation kinetics,and zero secondary waste generation—establishing it as a green and highly efficient recycling approach for magnesium alloy scrap.These findings provide fundamental theoretical and practical support for the recycling of Nd-containing magnesium alloys and contribute to the sustainable utilization of secondary rare earth resources.
基金supported by the National Natural Science Foundation of China(22125802,22108150,22338001)。
文摘Nervonic acid(NA) is a long-chain monounsaturated fatty acid with significant potential for neural fiber repair.In this study,a mixed fatty acid methyl ester was synthesized as the raw material through saponification of Acer truncatum Bunge seed oil.Based on the differences in boiling points and relative volatilities of various components,a four-stage vacuum batch distillation process was employed to enrich the nervonic acid methyl ester(NAME).The effect of distillation process parameters on enrichment efficiency was investigated,including distillation temperature,operating pressure,and reflux ratio.The purity of NAME achieved as 91.20% under optimal conditions and the corresponding yield was 48.91%.To further increase the purity,a low-temperature crystallization process was adopted and a final purity of NAME was obtained as 97.56%.Simulation of the above four-stage batch distillation was conducted using Aspen Plus software,and a continuous distillation processes was further simulated to establish a theoretical basis for future industrial-scale production.The results of experiments and simulation demonstrate that the integrated process of vacuum distillation and low-temperature crystallization exhibits remarkable separation performances,providing robust guidance for the production of high-purity NA.
