Camptothecine （CPT） and hydroxycamptothecin （HCPT）, two kinds of anti-cancer alkaloids, were extracted from Camptotheca acuminata leaves using homogenate extraction technology under different conditions such as th...Camptothecine （CPT） and hydroxycamptothecin （HCPT）, two kinds of anti-cancer alkaloids, were extracted from Camptotheca acuminata leaves using homogenate extraction technology under different conditions such as the ratio of material to liquid, ethanol concentration, and homogenate time. The optimum technology parameters for homogenate extraction of CPT and HCPT from C acuminata leaves were determined as homogenate time at 8 rain, ethanol concentration at 55% and the ratio of material to liquid at 1：15 （g：mL）. By using the optimized parameters, we obtained 0.639‰ extraction rate for CPT and 0.437‰ for HCPT. The extraction yields of CPT and HCPT extracted by homogenating technology were higher than those by other extractive methods, such as ultrasonic, reflux, shaking in water bath. It is concluded that the homogenate extraction technology was an efficient method for extracting CPT and HCPT from C acuminata leaves, with characteristics of less extraction time and high yield.展开更多
The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods （homogenized with distilled water at...The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods （homogenized with distilled water at room temperature, homogenized with 0.3% citric acid （w/v） at room temperature, 5- min boiling and homogenized with distilled water at room temperature, homogenized with 85℃ distilled water）, and after preserving at room temperature, the change of the Epigallocatechin gallate （EGCG） contents of the extracts was investigated. Results indicated that the EGCG content of homogenate extracted with 85℃ distilled water was the highest before the extract was preserved, followed by that of the extract homogenized with 0.3% citric acid at room temperature. During preservation, EGCG content changed obviously. The EGCG contents of homogenates extracted with distilled water at room temperature and 85℃ distilled water declined quickly and separately reduced to 21.52% and 54.6% of their initial contents after preservation for 12 h. The EGCG contents extracted by 0.3% citric acid （w/v） solvent at room temperature and 5- min boiling/homogenized with distilled water at room temperature declined relatively slowly ,and separately reduced to 76.9% and 85.16% of their initial contents after preservation for 12 h. It was also found that the citric acid can prevent the degradation of EGCG and the extract solution color is light green展开更多
BACKGROUND Pulmonary cryptococcosis(PC)is an opportunistic infectious disease of the respiratory system.Lung tissue biopsies,culture of respiratory samples(e.g.,sputum,lung tissue,pleural fluid,and bronchoalveolar lav...BACKGROUND Pulmonary cryptococcosis(PC)is an opportunistic infectious disease of the respiratory system.Lung tissue biopsies,culture of respiratory samples(e.g.,sputum,lung tissue,pleural fluid,and bronchoalveolar lavage fluid),and cryptococcal antigen(CrAg)testing are helpful for a definitive diagnosis.However,these tests are sometimes falsely negative.PC is often misdiagnosed or underdiagnosed owing to the absence of obvert symptoms,poor imaging specificity,and false-negative laboratory tests.CASE SUMMARY We report two female patients who underwent computed tomography-guided percutaneous needle pulmonary biopsy of a lung nodule for a confirmed diagnosis.In both patients,the CrAg test on the lung biopsy tissue homogenate was positive,while the serum CrAg test was negative.Combined with the lung tissue pathology,we made the diagnosis of PC.Antifungal therapy was effective in both patients.CONCLUSION Given the findings of our cases and the literature review,lung tissue homogenate CrAg testing can be helpful in improving the diagnosis of PC.展开更多
BACKGROUND：Live delivery limits the clinical application of maggot therapy. To date in China, there are no in vivo reports regarding wound healing mechanisms of maggot therapy or the effects of maggot homogenate on w...BACKGROUND：Live delivery limits the clinical application of maggot therapy. To date in China, there are no in vivo reports regarding wound healing mechanisms of maggot therapy or the effects of maggot homogenate on wound nerve regeneration.OBJECTIVE：To avoid complications due to the use of live maggots, an aseptic maggot homogenate was applied. Substance P （SP） and gene protein product 9.5 expression in a cutaneous wound was analyzed to explore possible mechanisms of neural regeneration and wound healing in the rat.DESIGN, TIME AND SETTING：A random grouping and controlled animal study was performed at the laboratory of the Department of Orthopedic Surgery, First Affiliated Hospital, Dalian Medical University from August 2008 to April 2009.MATERIALS：Live maggots were cultured and provided by the laboratory of the Department of Orthopedic Surgery of the First Affiliated Hospital, Dalian Medical University, China.METHODS：A total of 48 adult rats were selected and two acute, full-thickness wounds （round, 1.5 cm diameter） were created on the back of each rat. The two wounds were randomly assigned to homogenate product and control groups. Following two-step disinfection of maggots, a homogenate was produced from 10 maggots and applied to the wound area in the homogenate product group, while the wounds in the control group were treated with normal saline alone.MAIN OUTCOME MEASURES：On days 1,3, 7, 10, 14, and 21 following injury, the wound tissue was excised. Histological examination of the wound was observed by hematoxylin and eosin staining or Masson＇s Trichrome staining. SP and protein gene product 9.5 expressions were examined by immunohistochemistry to evaluate wound neural regeneration.RESULTS：On days 7, 10, and 14, the rate of wound healing was significantly greater in the homogenate product group compared with the control group （P 〈 0.05）, and homogenate healing was better than that seen in the control group. On days 3, 7, and 10, SP expression in cells and regenerative nerves was significantly greater in the homogenate product group compared with the control group （P 〈 0.05）. On days 7 and 10, protein gene product 9.5 expression was detected in the regenerative nerve, and expression level was significantly greater in the homogenate product group compared with the control group （P 〈 0.05）.CONCLUSION：Maggot homogenate resulted in upregulated SP and protein gene product 9.5 expressions, thereby promoting neural regeneration and wound healing.展开更多
Camptothecine(CPT) and hydroxycamptothecin(HCPT), two kinds of anti-cancer alkaloids, were extracted from Camptotheca acuminata leaves using homogenate extraction technology under different conditions such as the rati...Camptothecine(CPT) and hydroxycamptothecin(HCPT), two kinds of anti-cancer alkaloids, were extracted from Camptotheca acuminata leaves using homogenate extraction technology under different conditions such as the ratio of material to liquid, ethanol concentration, and homogenate time.The optimum technology parameters for homogenate extraction of CPT and HCPT from C.acuminata leaves were determined as homogenate time at 8 min, ethanol concentration at 55% and the ratio of material to liquid at 1:15(g:mL).By using the optimized parameters, we obtained 0.639‰ extraction rate for CPT and 0.437‰ for HCPT.The extraction yields of CPT and HCPT extracted by homogenating technology were higher than those by other extractive methods, such as ultrasonic, reflux, shaking in water bath.It is concluded that the homogenate extraction technology was an efficient method for extracting CPT and HCPT from C.acuminata leaves, with characteristics of less extraction time and high yield.展开更多
To date, complex components of available reagents have been used for directional induction of neural stem cells into dopaminergic neurons, resulting in a poor ability to repeat experiments. This study sought to invest...To date, complex components of available reagents have been used for directional induction of neural stem cells into dopaminergic neurons, resulting in a poor ability to repeat experiments. This study sought to investigate whether a homogenate of the substantia nigra of adult rats and/or basic fibroblast growth factor could directionally induce neural stem cells derived from the subventricular zone of embryonic rats to differentiate into dopaminergic neurons. Tyrosine hydroxylase-positive cells were observed exclusively after induction with the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor for 48 hours in vitro. However, in the groups treated with homogenate supernatant or basic fibroblast growth factor alone, tyrosine hydroxylase expression was not observed. Moreover, the content of dopamine in the culture medium of subventricular zone neurons was significantly increased at 48 hours after induction with the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor. Experimental findings indicate that the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor could directionally induce neural stem cells derived from the subventricular zone of embryonic rats to differentiate into dopaminergic neurons in the substantia nigra with the ability to secrete dopamine.展开更多
Significant research has been conducted on using natural plant-based homogenates(NPBH)as additives to improve the quality of yogurt.This paper reviews the effects,mechanisms,and research methods of NPBH as additives t...Significant research has been conducted on using natural plant-based homogenates(NPBH)as additives to improve the quality of yogurt.This paper reviews the effects,mechanisms,and research methods of NPBH as additives to the probiotic content,texture,flavor,and nutritional value of yogurt.The mechanisms by which NPBH promotes the growth of lactic acid bacteria are reviewed,including nutrients in the homogenates,a suitable buffering environment,and the metabolic production of probiotics.Fructose,pectin,dietary fiber,protein,and polysaccharides are the primary influences on the yogurt texture.The aromatic precursors contained in NPBH,their contribution to yogurt flavor,and the health benefits of yogurt nutritional fortification are detailed.In the future,priority could be given to adding Chinese herbs(like wolfberry,saffron,and Rhodiola)with preventing alcoholic liver,anti-aging,blood pressure reduction,and other disease treatment or prevention functions to the yogurt to achieve a win-win situation.In addition,research on the function of NPBH yogurt should focus on the clinical implications.展开更多
Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indice...Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indices,has provided a fresh perspective and valuable insight into the study of freezing of gait in Parkinson's disease.It has been revealed that Parkinson's disease is accompanied by widespread irregularities in inherent brain network activity.However,the effective integration of the multi-level indices of resting-state functional magnetic resonance imaging into clinical settings for the diagnosis of freezing of gait in Parkinson's disease remains a challenge.Although previous studies have demonstrated that radiomics can extract optimal features as biomarkers to identify or predict diseases,a knowledge gap still exists in the field of freezing of gait in Parkinson's disease.This cross-sectional study aimed to evaluate the ability of radiomics features based on multi-level indices of resting-state functional magnetic resonance imaging,along with clinical features,to distinguish between Parkinson's disease patients with and without freezing of gait.We recruited 28 patients with Parkinson's disease who had freezing of gait(15 men and 13 women,average age 63 years)and 30 patients with Parkinson's disease who had no freezing of gait(16 men and 14 women,average age 64 years).Magnetic resonance imaging scans were obtained using a 3.0T scanner to extract the mean amplitude of low-frequency fluctuations,mean regional homogeneity,and degree centrality.Neurological and clinical characteristics were also evaluated.We used the least absolute shrinkage and selection operator algorithm to extract features and established feedforward neural network models based solely on resting-state functional magnetic resonance imaging indicators.We then performed predictive analysis of three distinct groups based on resting-state functional magnetic resonance imaging indicators indicators combined with clinical features.Subsequently,we conducted 100 additional five-fold cross-validations to determine the most effective model for each classification task and evaluated the performance of the model using the area under the receiver operating characteristic curve.The results showed that when differentiating patients with Parkinson's disease who had freezing of gait from those who did not have freezing of gait,or from healthy controls,the models using only the mean regional homogeneity values achieved the highest area under the receiver operating characteristic curve values of 0.750(with an accuracy of 70.9%)and 0.759(with an accuracy of 65.3%),respectively.When classifying patients with Parkinson's disease who had freezing of gait from those who had no freezing of gait,the model using the mean amplitude of low-frequency fluctuation values combined with two clinical features achieved the highest area under the receiver operating characteristic curve of 0.847(with an accuracy of 74.3%).The most significant features for patients with Parkinson's disease who had freezing of gait were amplitude of low-frequency fluctuation alterations in the left parahippocampal gyrus and two clinical characteristics:Montreal Cognitive Assessment and Hamilton Depression Scale scores.Our findings suggest that radiomics features derived from resting-state functional magnetic resonance imaging indices and clinical information can serve as valuable indices for the identification of freezing of gait in Parkinson's disease.展开更多
Arteannuic acid and(-)11R,13-d(?)ydroarteannuic acid are the key intermediates in the biosynthesis of arteannuin by the leaf homogenate of Artemisia annua L.,and arteannuic acid and epoxyarteannuic acid are the interm...Arteannuic acid and(-)11R,13-d(?)ydroarteannuic acid are the key intermediates in the biosynthesis of arteannuin by the leaf homogenate of Artemisia annua L.,and arteannuic acid and epoxyarteannuic acid are the intermediates of arteannuin B.and epoxyarteannuic acid can not be transformed into arteannuin by the homogenate.展开更多
The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-...The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%).展开更多
In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order hom...In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order homogenization(ROH)approach.The ROH method typically involves solving multiple finite element problems under periodic conditions to evaluate elastic strain and eigenstrain influence functions in an‘off-line’stage,which offers substantial cost savings compared to direct computational homogenization methods.Due to the unique structure of the fibrous unit cell,“off-line”stage calculation can be eliminated by influence functions obtained analytically.Introducing the standard solid model to the ROH method enables the creation of a comprehensive analytical homogeneous viscoelastic constitutive model.This method treats fibrous composite materials as homogeneous,anisotropic viscoelastic materials,significantly reducing computational time due to its analytical nature.This approach also enables precise determination of a homogenized anisotropic relaxation modulus and accurate capture of various viscoelastic responses under different loading conditions.Three sets of numerical examples,including unit cell tests,three-point beam bending tests,and torsion tests,are given to demonstrate the predictive performance of the homogenized viscoelastic model.Furthermore,the model is validated against experimental measurements,confirming its accuracy and reliability.展开更多
As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal...As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.展开更多
Porous organic cages(POCs)with permanent porosity and excellent host–vip property hold great potentials in regulating ion transport behavior,yet their feasibility as solid-state electrolytes has never been testifie...Porous organic cages(POCs)with permanent porosity and excellent host–vip property hold great potentials in regulating ion transport behavior,yet their feasibility as solid-state electrolytes has never been testified in a practical battery.Herein,we design and fabricate a quasi-solid-state electrolyte(QSSE)based on a POC to enable the stable operation of Li-metal batteries(LMBs).Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC,the resulting POC-based QSSE exhibits a high Li+transference number of 0.67 and a high ionic conductivity of 1.25×10^(−4) S cm^(−1) with a low activation energy of 0.17 eV.These allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 h.As a proof of concept,the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85%capacity retention after 1000 cycles.Therefore,our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems,such as Na and K batteries.展开更多
Social interaction with peer pressure is widely studied in social network analysis.Game theory can be utilized to model dynamic social interaction,and one class of game network models assumes that people’s decision p...Social interaction with peer pressure is widely studied in social network analysis.Game theory can be utilized to model dynamic social interaction,and one class of game network models assumes that people’s decision payoff functions hinge on individual covariates and the choices of their friends.However,peer pressure would be misidentified and induce a non-negligible bias when incomplete covariates are involved in the game model.For this reason,we develop a generalized constant peer effects model based on homogeneity structure in dynamic social networks.The new model can effectively avoid bias through homogeneity pursuit and can be applied to a wider range of scenarios.To estimate peer pressure in the model,we first present two algorithms based on the initialize expand merge method and the polynomial-time twostage method to estimate homogeneity parameters.Then we apply the nested pseudo-likelihood method and obtain consistent estimators of peer pressure.Simulation evaluations show that our proposed methodology can achieve desirable and effective results in terms of the community misclassification rate and parameter estimation error.We also illustrate the advantages of our model in the empirical analysis when compared with a benchmark model.展开更多
Hot compression tests for GH4706 alloy were performed at a true strain of 1.2 within the temperature range of 950-1150℃ and the strain rate range of 0.001-1 s^(-1).The optimal hot deformation temperature and strain r...Hot compression tests for GH4706 alloy were performed at a true strain of 1.2 within the temperature range of 950-1150℃ and the strain rate range of 0.001-1 s^(-1).The optimal hot deformation temperature and strain rate range were determined using nephogram maps of dynamic recrystallization fraction,average grain size,and grain distribution standard deviation.Processing maps at true strains from 0.4 to 0.9 were generated based on flow stress curves to identify the strain corresponding to optimal microstructure homogenization efficiency at various temperatures and strain rates.Results show that within the optimal parameter range,under the conditions of 1150℃ and 0.01 s^(-1),the true strain of about 0.6 results in the optimal microstructure homogenization efficiency.The grain orientation spread maps obtained from the experiment also confirms this conclusion.This study provides an effective method for microstructure homogenization control of GH4706 alloy and an effective reference for the minimum strain threshold of the local part of the forging in engineering.展开更多
To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)...To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)and a 1,5‑cyclooctadiene(cod)molecule:[Ir(cod)(κ^(3)‑CN^(im)P)]Cl(1⁃Cl),[Ir(cod)(κ^(3)‑CN^(im)P)]PF6(1⁃PF_(6)),and[Ir(cod)(κ^(3)‑CNHP)]Cl(2).The^(1)H NMR spectra,^(31)P NMR spectra,and high‑resolution mass spectra verify the successful synthesis of these three Ir(Ⅰ)‑CNP complexes.Furthermore,single‑crystal X‑ray diffraction analysis confirms the coordination geometry of 1⁃PF_(6).The strong Ir—C(NHC)bond suggests that the carbene carbon plays an enhanced anchoring role to iridium due to its strongσ‑donating ability,which helps stabilize the active metal species during CO_(2)hydrogenation.As a result,the Ir(Ⅰ)‑CNP complex exhibits remarkable activity and long catalytic lifetime for the hydrogenation of CO_(2)to formate,reaching a turnover number(TON)of 1.16×10^(6)after 150 h at a high temperature of 170℃,which was a relatively high value among all the Ir complexes.CCDC:2384071,1⁃PF_(6).展开更多
[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which...[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which were advantageous for the protection and reproduction of V.macrolepis.[Method] V.macrolepis was used as test materials for the hemagglutination test by dialdehyde fixation to prove the existence of lectins in muscle crude homogenate of Varicorhinus macrolepis and study the physical and chemical characters.[Result] Lectins in muscle crude homogenate of V.macrolepis had shown hemagglutination effects on erythrocytes of six types of animals and had the maximum hemagglutination activity against rabbit erythrocytes,which belonged to the S-type lectins with optimal pH ranged from 4 to 8 and optimal temperature at 60 ℃.Results from the saccharide inhibition test had indicated that the sucrose was the only kind of saccharide which had inhibited the hemagglutination,suggesting that sucrose had played an important role in the process of recognition and aggregation of lectins.[Conclusion] It had been speculated that the optimal pH ranges for thermal sensitivity and hemagglutination activity of lectins in different types of aquatic organisms were similar.展开更多
Photoredox catalysis has made significant advances in stateof-the-art chemical synthesis,drawing energy from inexhaustible light and enabling various organic transformations to occur under mild reaction conditions.Ove...Photoredox catalysis has made significant advances in stateof-the-art chemical synthesis,drawing energy from inexhaustible light and enabling various organic transformations to occur under mild reaction conditions.Over the past few years,a variety of homogeneous and heterogeneous photocatalysts have been applied in the photoredox catalysis.Heterogeneous photoredox catalysis offers advantages such as easy separation and superior recyclability compared to homogeneous counterparts,although homogenous catalysts are usually associated with higher activities and selectivity.From a practical perspective,an optimal photoredox catalytic system would integrate the advantages of both homogeneous and heterogeneous cases.展开更多
The acoustic wave propagation in gas-saturated double-porosity materials composed of a microporous matrix and mesopores with arrays of plate-type resonators is investigated.A macroscopic description,established with t...The acoustic wave propagation in gas-saturated double-porosity materials composed of a microporous matrix and mesopores with arrays of plate-type resonators is investigated.A macroscopic description,established with the two-scale asymptotic homogenization method,evidences the combined effect of inner resonances on the acoustic properties of the respective effective visco-thermal fluid.One type of resonance originates from strong pore-scale fluid-structure interaction,while the other one arises from pressure diffusion.These phenomena respectively cause weakly and highly damped resonances,which are activated by internal momentum or mass sources,and can largely influence,depending on the material's morphology,either the effective fluid's dynamic density,compressibility,or both.We introduce semi-analytical models to illustrate the key effective properties of the studied multiscale metamaterials.The results provide insights for the bottom-up design of multiscale acoustic metamaterials with exotic behaviors,such as the negative,very slow,or supersonic phase velocity,as well as sub-wavelength bandgaps.展开更多
Based on microstructure analysis,diffusion theory,and hot deformation experiments,the solidification microstructure and element segregation of the Alloy 625 Plus ingot,the diffusion kinetics of Ti,Nb,and Mo during hom...Based on microstructure analysis,diffusion theory,and hot deformation experiments,the solidification microstructure and element segregation of the Alloy 625 Plus ingot,the diffusion kinetics of Ti,Nb,and Mo during homogenization and the hot deformation behavior of the homogenized ingot were investigated in this study.The results indicate that:(1)the solidified ingot exhibits a typical dendritic microstructure,and significant element segregation occurs,leading to the presence of Ti,Nb,and Mo-rich precipitates in the interdendritic region;(2)Following homogenization,the degree of element segregation in the ingot is significantly reduced.The diffusion coefficients(D)of Ti,Nb,and Mo under various homogenization conditions were calculated.Subsequently,the diffusion constants(D_(0))and activation energies(Q)of Ti,Nb,and Mo were obtained to be 0.01432,0.00397 and 0.00195 cm^(2)/s and 244.851,230.312,and 222.125 kJ/mol,respectively.Finally,the diffusion kinetics formulas for Ti,Nb,and Mo in Alloy 625 Plus were established.After homogenization at 1220℃for 8 h,the alloy exhibits low deformation resistance,a high degree of recrystallization,and optimal deformation coordination ability.Therefore,this represents a rational single-stage homogenization process.展开更多
文摘Camptothecine （CPT） and hydroxycamptothecin （HCPT）, two kinds of anti-cancer alkaloids, were extracted from Camptotheca acuminata leaves using homogenate extraction technology under different conditions such as the ratio of material to liquid, ethanol concentration, and homogenate time. The optimum technology parameters for homogenate extraction of CPT and HCPT from C acuminata leaves were determined as homogenate time at 8 rain, ethanol concentration at 55% and the ratio of material to liquid at 1：15 （g：mL）. By using the optimized parameters, we obtained 0.639‰ extraction rate for CPT and 0.437‰ for HCPT. The extraction yields of CPT and HCPT extracted by homogenating technology were higher than those by other extractive methods, such as ultrasonic, reflux, shaking in water bath. It is concluded that the homogenate extraction technology was an efficient method for extracting CPT and HCPT from C acuminata leaves, with characteristics of less extraction time and high yield.
文摘The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods （homogenized with distilled water at room temperature, homogenized with 0.3% citric acid （w/v） at room temperature, 5- min boiling and homogenized with distilled water at room temperature, homogenized with 85℃ distilled water）, and after preserving at room temperature, the change of the Epigallocatechin gallate （EGCG） contents of the extracts was investigated. Results indicated that the EGCG content of homogenate extracted with 85℃ distilled water was the highest before the extract was preserved, followed by that of the extract homogenized with 0.3% citric acid at room temperature. During preservation, EGCG content changed obviously. The EGCG contents of homogenates extracted with distilled water at room temperature and 85℃ distilled water declined quickly and separately reduced to 21.52% and 54.6% of their initial contents after preservation for 12 h. The EGCG contents extracted by 0.3% citric acid （w/v） solvent at room temperature and 5- min boiling/homogenized with distilled water at room temperature declined relatively slowly ,and separately reduced to 76.9% and 85.16% of their initial contents after preservation for 12 h. It was also found that the citric acid can prevent the degradation of EGCG and the extract solution color is light green
文摘BACKGROUND Pulmonary cryptococcosis(PC)is an opportunistic infectious disease of the respiratory system.Lung tissue biopsies,culture of respiratory samples(e.g.,sputum,lung tissue,pleural fluid,and bronchoalveolar lavage fluid),and cryptococcal antigen(CrAg)testing are helpful for a definitive diagnosis.However,these tests are sometimes falsely negative.PC is often misdiagnosed or underdiagnosed owing to the absence of obvert symptoms,poor imaging specificity,and false-negative laboratory tests.CASE SUMMARY We report two female patients who underwent computed tomography-guided percutaneous needle pulmonary biopsy of a lung nodule for a confirmed diagnosis.In both patients,the CrAg test on the lung biopsy tissue homogenate was positive,while the serum CrAg test was negative.Combined with the lung tissue pathology,we made the diagnosis of PC.Antifungal therapy was effective in both patients.CONCLUSION Given the findings of our cases and the literature review,lung tissue homogenate CrAg testing can be helpful in improving the diagnosis of PC.
基金Supported by the National Natural Science Foundation of China,No. 30873336
文摘BACKGROUND：Live delivery limits the clinical application of maggot therapy. To date in China, there are no in vivo reports regarding wound healing mechanisms of maggot therapy or the effects of maggot homogenate on wound nerve regeneration.OBJECTIVE：To avoid complications due to the use of live maggots, an aseptic maggot homogenate was applied. Substance P （SP） and gene protein product 9.5 expression in a cutaneous wound was analyzed to explore possible mechanisms of neural regeneration and wound healing in the rat.DESIGN, TIME AND SETTING：A random grouping and controlled animal study was performed at the laboratory of the Department of Orthopedic Surgery, First Affiliated Hospital, Dalian Medical University from August 2008 to April 2009.MATERIALS：Live maggots were cultured and provided by the laboratory of the Department of Orthopedic Surgery of the First Affiliated Hospital, Dalian Medical University, China.METHODS：A total of 48 adult rats were selected and two acute, full-thickness wounds （round, 1.5 cm diameter） were created on the back of each rat. The two wounds were randomly assigned to homogenate product and control groups. Following two-step disinfection of maggots, a homogenate was produced from 10 maggots and applied to the wound area in the homogenate product group, while the wounds in the control group were treated with normal saline alone.MAIN OUTCOME MEASURES：On days 1,3, 7, 10, 14, and 21 following injury, the wound tissue was excised. Histological examination of the wound was observed by hematoxylin and eosin staining or Masson＇s Trichrome staining. SP and protein gene product 9.5 expressions were examined by immunohistochemistry to evaluate wound neural regeneration.RESULTS：On days 7, 10, and 14, the rate of wound healing was significantly greater in the homogenate product group compared with the control group （P 〈 0.05）, and homogenate healing was better than that seen in the control group. On days 3, 7, and 10, SP expression in cells and regenerative nerves was significantly greater in the homogenate product group compared with the control group （P 〈 0.05）. On days 7 and 10, protein gene product 9.5 expression was detected in the regenerative nerve, and expression level was significantly greater in the homogenate product group compared with the control group （P 〈 0.05）.CONCLUSION：Maggot homogenate resulted in upregulated SP and protein gene product 9.5 expressions, thereby promoting neural regeneration and wound healing.
基金supported by National Key Tech-nology R & D Program (grant no. 2006BAD18B04).
文摘Camptothecine(CPT) and hydroxycamptothecin(HCPT), two kinds of anti-cancer alkaloids, were extracted from Camptotheca acuminata leaves using homogenate extraction technology under different conditions such as the ratio of material to liquid, ethanol concentration, and homogenate time.The optimum technology parameters for homogenate extraction of CPT and HCPT from C.acuminata leaves were determined as homogenate time at 8 min, ethanol concentration at 55% and the ratio of material to liquid at 1:15(g:mL).By using the optimized parameters, we obtained 0.639‰ extraction rate for CPT and 0.437‰ for HCPT.The extraction yields of CPT and HCPT extracted by homogenating technology were higher than those by other extractive methods, such as ultrasonic, reflux, shaking in water bath.It is concluded that the homogenate extraction technology was an efficient method for extracting CPT and HCPT from C.acuminata leaves, with characteristics of less extraction time and high yield.
基金sponsored by the General Program of Yunnan Provincial Application Basic Research, No. 2008ZC109M
文摘To date, complex components of available reagents have been used for directional induction of neural stem cells into dopaminergic neurons, resulting in a poor ability to repeat experiments. This study sought to investigate whether a homogenate of the substantia nigra of adult rats and/or basic fibroblast growth factor could directionally induce neural stem cells derived from the subventricular zone of embryonic rats to differentiate into dopaminergic neurons. Tyrosine hydroxylase-positive cells were observed exclusively after induction with the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor for 48 hours in vitro. However, in the groups treated with homogenate supernatant or basic fibroblast growth factor alone, tyrosine hydroxylase expression was not observed. Moreover, the content of dopamine in the culture medium of subventricular zone neurons was significantly increased at 48 hours after induction with the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor. Experimental findings indicate that the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor could directionally induce neural stem cells derived from the subventricular zone of embryonic rats to differentiate into dopaminergic neurons in the substantia nigra with the ability to secrete dopamine.
基金supported by the Natural Science Funding of China(31972048)the outstanding youth fund of Zhejiang Province(LR22C200001).
文摘Significant research has been conducted on using natural plant-based homogenates(NPBH)as additives to improve the quality of yogurt.This paper reviews the effects,mechanisms,and research methods of NPBH as additives to the probiotic content,texture,flavor,and nutritional value of yogurt.The mechanisms by which NPBH promotes the growth of lactic acid bacteria are reviewed,including nutrients in the homogenates,a suitable buffering environment,and the metabolic production of probiotics.Fructose,pectin,dietary fiber,protein,and polysaccharides are the primary influences on the yogurt texture.The aromatic precursors contained in NPBH,their contribution to yogurt flavor,and the health benefits of yogurt nutritional fortification are detailed.In the future,priority could be given to adding Chinese herbs(like wolfberry,saffron,and Rhodiola)with preventing alcoholic liver,anti-aging,blood pressure reduction,and other disease treatment or prevention functions to the yogurt to achieve a win-win situation.In addition,research on the function of NPBH yogurt should focus on the clinical implications.
基金supported by the National Natural Science Foundation of China,No.82071909(to GF)the Natural Science Foundation of Liaoning Province,No.2023-MS-07(to HL)。
文摘Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indices,has provided a fresh perspective and valuable insight into the study of freezing of gait in Parkinson's disease.It has been revealed that Parkinson's disease is accompanied by widespread irregularities in inherent brain network activity.However,the effective integration of the multi-level indices of resting-state functional magnetic resonance imaging into clinical settings for the diagnosis of freezing of gait in Parkinson's disease remains a challenge.Although previous studies have demonstrated that radiomics can extract optimal features as biomarkers to identify or predict diseases,a knowledge gap still exists in the field of freezing of gait in Parkinson's disease.This cross-sectional study aimed to evaluate the ability of radiomics features based on multi-level indices of resting-state functional magnetic resonance imaging,along with clinical features,to distinguish between Parkinson's disease patients with and without freezing of gait.We recruited 28 patients with Parkinson's disease who had freezing of gait(15 men and 13 women,average age 63 years)and 30 patients with Parkinson's disease who had no freezing of gait(16 men and 14 women,average age 64 years).Magnetic resonance imaging scans were obtained using a 3.0T scanner to extract the mean amplitude of low-frequency fluctuations,mean regional homogeneity,and degree centrality.Neurological and clinical characteristics were also evaluated.We used the least absolute shrinkage and selection operator algorithm to extract features and established feedforward neural network models based solely on resting-state functional magnetic resonance imaging indicators.We then performed predictive analysis of three distinct groups based on resting-state functional magnetic resonance imaging indicators indicators combined with clinical features.Subsequently,we conducted 100 additional five-fold cross-validations to determine the most effective model for each classification task and evaluated the performance of the model using the area under the receiver operating characteristic curve.The results showed that when differentiating patients with Parkinson's disease who had freezing of gait from those who did not have freezing of gait,or from healthy controls,the models using only the mean regional homogeneity values achieved the highest area under the receiver operating characteristic curve values of 0.750(with an accuracy of 70.9%)and 0.759(with an accuracy of 65.3%),respectively.When classifying patients with Parkinson's disease who had freezing of gait from those who had no freezing of gait,the model using the mean amplitude of low-frequency fluctuation values combined with two clinical features achieved the highest area under the receiver operating characteristic curve of 0.847(with an accuracy of 74.3%).The most significant features for patients with Parkinson's disease who had freezing of gait were amplitude of low-frequency fluctuation alterations in the left parahippocampal gyrus and two clinical characteristics:Montreal Cognitive Assessment and Hamilton Depression Scale scores.Our findings suggest that radiomics features derived from resting-state functional magnetic resonance imaging indices and clinical information can serve as valuable indices for the identification of freezing of gait in Parkinson's disease.
基金This project was supported by National Natural Science Foundation of China.
文摘Arteannuic acid and(-)11R,13-d(?)ydroarteannuic acid are the key intermediates in the biosynthesis of arteannuin by the leaf homogenate of Artemisia annua L.,and arteannuic acid and epoxyarteannuic acid are the intermediates of arteannuin B.and epoxyarteannuic acid can not be transformed into arteannuin by the homogenate.
基金Project(2018YFC1900403) supported by the National Key Research and Development Program of ChinaProject(CX20210197) supported by the Postgraduate Scientific Research Innovation Project of Hunan Province,China+1 种基金Project(202206370103) supported by the China Scholarship CouncilProject(2021zzts0115) supported by the Fundamental Research Funds for the Central Universities,China。
文摘The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%).
基金support by the National Key R&D Program of China(Grant No.2023YFA1008901)the National Natural Science Foundation of China(Grant Nos.11988102,12172009)is gratefully acknowledged.
文摘In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order homogenization(ROH)approach.The ROH method typically involves solving multiple finite element problems under periodic conditions to evaluate elastic strain and eigenstrain influence functions in an‘off-line’stage,which offers substantial cost savings compared to direct computational homogenization methods.Due to the unique structure of the fibrous unit cell,“off-line”stage calculation can be eliminated by influence functions obtained analytically.Introducing the standard solid model to the ROH method enables the creation of a comprehensive analytical homogeneous viscoelastic constitutive model.This method treats fibrous composite materials as homogeneous,anisotropic viscoelastic materials,significantly reducing computational time due to its analytical nature.This approach also enables precise determination of a homogenized anisotropic relaxation modulus and accurate capture of various viscoelastic responses under different loading conditions.Three sets of numerical examples,including unit cell tests,three-point beam bending tests,and torsion tests,are given to demonstrate the predictive performance of the homogenized viscoelastic model.Furthermore,the model is validated against experimental measurements,confirming its accuracy and reliability.
基金financially supported by the National Key R&D Program of China(No.2022YFE0121300)the National Natural Science Foundation of China(No.52374376)the Introduction Plan for High-end Foreign Experts(No.G2023105001L)。
文摘As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.
基金supported by the National Natural Science Foundation of China(No.92372123)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515012057,2022B1515020005,2023B1515130004)Guangzhou Basic and Applied Basic Research Foundation(No.202201011342).
文摘Porous organic cages(POCs)with permanent porosity and excellent host–vip property hold great potentials in regulating ion transport behavior,yet their feasibility as solid-state electrolytes has never been testified in a practical battery.Herein,we design and fabricate a quasi-solid-state electrolyte(QSSE)based on a POC to enable the stable operation of Li-metal batteries(LMBs).Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC,the resulting POC-based QSSE exhibits a high Li+transference number of 0.67 and a high ionic conductivity of 1.25×10^(−4) S cm^(−1) with a low activation energy of 0.17 eV.These allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 h.As a proof of concept,the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85%capacity retention after 1000 cycles.Therefore,our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems,such as Na and K batteries.
基金supported by the National Nature Science Foundation of China(71771201,72531009,71973001)the USTC Research Funds of the Double First-Class Initiative(FSSF-A-240202).
文摘Social interaction with peer pressure is widely studied in social network analysis.Game theory can be utilized to model dynamic social interaction,and one class of game network models assumes that people’s decision payoff functions hinge on individual covariates and the choices of their friends.However,peer pressure would be misidentified and induce a non-negligible bias when incomplete covariates are involved in the game model.For this reason,we develop a generalized constant peer effects model based on homogeneity structure in dynamic social networks.The new model can effectively avoid bias through homogeneity pursuit and can be applied to a wider range of scenarios.To estimate peer pressure in the model,we first present two algorithms based on the initialize expand merge method and the polynomial-time twostage method to estimate homogeneity parameters.Then we apply the nested pseudo-likelihood method and obtain consistent estimators of peer pressure.Simulation evaluations show that our proposed methodology can achieve desirable and effective results in terms of the community misclassification rate and parameter estimation error.We also illustrate the advantages of our model in the empirical analysis when compared with a benchmark model.
基金National Key R&D Program Project(2022YFB3705103)。
文摘Hot compression tests for GH4706 alloy were performed at a true strain of 1.2 within the temperature range of 950-1150℃ and the strain rate range of 0.001-1 s^(-1).The optimal hot deformation temperature and strain rate range were determined using nephogram maps of dynamic recrystallization fraction,average grain size,and grain distribution standard deviation.Processing maps at true strains from 0.4 to 0.9 were generated based on flow stress curves to identify the strain corresponding to optimal microstructure homogenization efficiency at various temperatures and strain rates.Results show that within the optimal parameter range,under the conditions of 1150℃ and 0.01 s^(-1),the true strain of about 0.6 results in the optimal microstructure homogenization efficiency.The grain orientation spread maps obtained from the experiment also confirms this conclusion.This study provides an effective method for microstructure homogenization control of GH4706 alloy and an effective reference for the minimum strain threshold of the local part of the forging in engineering.
文摘To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)and a 1,5‑cyclooctadiene(cod)molecule:[Ir(cod)(κ^(3)‑CN^(im)P)]Cl(1⁃Cl),[Ir(cod)(κ^(3)‑CN^(im)P)]PF6(1⁃PF_(6)),and[Ir(cod)(κ^(3)‑CNHP)]Cl(2).The^(1)H NMR spectra,^(31)P NMR spectra,and high‑resolution mass spectra verify the successful synthesis of these three Ir(Ⅰ)‑CNP complexes.Furthermore,single‑crystal X‑ray diffraction analysis confirms the coordination geometry of 1⁃PF_(6).The strong Ir—C(NHC)bond suggests that the carbene carbon plays an enhanced anchoring role to iridium due to its strongσ‑donating ability,which helps stabilize the active metal species during CO_(2)hydrogenation.As a result,the Ir(Ⅰ)‑CNP complex exhibits remarkable activity and long catalytic lifetime for the hydrogenation of CO_(2)to formate,reaching a turnover number(TON)of 1.16×10^(6)after 150 h at a high temperature of 170℃,which was a relatively high value among all the Ir complexes.CCDC:2384071,1⁃PF_(6).
基金Supported by National Natural Science Foundation of China(3070007131172074)National Natural Science Foundation of Shandong Province(ZR2010CL002)~~
文摘[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which were advantageous for the protection and reproduction of V.macrolepis.[Method] V.macrolepis was used as test materials for the hemagglutination test by dialdehyde fixation to prove the existence of lectins in muscle crude homogenate of Varicorhinus macrolepis and study the physical and chemical characters.[Result] Lectins in muscle crude homogenate of V.macrolepis had shown hemagglutination effects on erythrocytes of six types of animals and had the maximum hemagglutination activity against rabbit erythrocytes,which belonged to the S-type lectins with optimal pH ranged from 4 to 8 and optimal temperature at 60 ℃.Results from the saccharide inhibition test had indicated that the sucrose was the only kind of saccharide which had inhibited the hemagglutination,suggesting that sucrose had played an important role in the process of recognition and aggregation of lectins.[Conclusion] It had been speculated that the optimal pH ranges for thermal sensitivity and hemagglutination activity of lectins in different types of aquatic organisms were similar.
基金the National Natural Science Foundation of China(No.22271060),The Department of Chemistry at Fudan University and College of Chemistry and Chemical Engineering at Ningxia University is gratefully acknowledged.
文摘Photoredox catalysis has made significant advances in stateof-the-art chemical synthesis,drawing energy from inexhaustible light and enabling various organic transformations to occur under mild reaction conditions.Over the past few years,a variety of homogeneous and heterogeneous photocatalysts have been applied in the photoredox catalysis.Heterogeneous photoredox catalysis offers advantages such as easy separation and superior recyclability compared to homogeneous counterparts,although homogenous catalysts are usually associated with higher activities and selectivity.From a practical perspective,an optimal photoredox catalytic system would integrate the advantages of both homogeneous and heterogeneous cases.
基金Project supported by the Chilean National Agency for Research and Development(ANID)through Grants ANID FONDECYT Regular(Nos.1211310 and 1250496)ANID Anillo de Tecnologia(No.ACT240015)the Polish National Science Centre(NCN)through Grant Agreement(No.2021/41/B/ST8/04492)。
文摘The acoustic wave propagation in gas-saturated double-porosity materials composed of a microporous matrix and mesopores with arrays of plate-type resonators is investigated.A macroscopic description,established with the two-scale asymptotic homogenization method,evidences the combined effect of inner resonances on the acoustic properties of the respective effective visco-thermal fluid.One type of resonance originates from strong pore-scale fluid-structure interaction,while the other one arises from pressure diffusion.These phenomena respectively cause weakly and highly damped resonances,which are activated by internal momentum or mass sources,and can largely influence,depending on the material's morphology,either the effective fluid's dynamic density,compressibility,or both.We introduce semi-analytical models to illustrate the key effective properties of the studied multiscale metamaterials.The results provide insights for the bottom-up design of multiscale acoustic metamaterials with exotic behaviors,such as the negative,very slow,or supersonic phase velocity,as well as sub-wavelength bandgaps.
基金Project(52174303)supported by the National Natural Science Foundation of ChinaProject(2023JH2/101700302)supported by the Joint Program of Science and Technology Plans in Liaoning Province,China。
文摘Based on microstructure analysis,diffusion theory,and hot deformation experiments,the solidification microstructure and element segregation of the Alloy 625 Plus ingot,the diffusion kinetics of Ti,Nb,and Mo during homogenization and the hot deformation behavior of the homogenized ingot were investigated in this study.The results indicate that:(1)the solidified ingot exhibits a typical dendritic microstructure,and significant element segregation occurs,leading to the presence of Ti,Nb,and Mo-rich precipitates in the interdendritic region;(2)Following homogenization,the degree of element segregation in the ingot is significantly reduced.The diffusion coefficients(D)of Ti,Nb,and Mo under various homogenization conditions were calculated.Subsequently,the diffusion constants(D_(0))and activation energies(Q)of Ti,Nb,and Mo were obtained to be 0.01432,0.00397 and 0.00195 cm^(2)/s and 244.851,230.312,and 222.125 kJ/mol,respectively.Finally,the diffusion kinetics formulas for Ti,Nb,and Mo in Alloy 625 Plus were established.After homogenization at 1220℃for 8 h,the alloy exhibits low deformation resistance,a high degree of recrystallization,and optimal deformation coordination ability.Therefore,this represents a rational single-stage homogenization process.
