To address the current issues with the conventional slide gate system utilized in the steel teeming process,a unique electromagnetic induction controlled automated steel teeming(EICAST)technology has been developed.Co...To address the current issues with the conventional slide gate system utilized in the steel teeming process,a unique electromagnetic induction controlled automated steel teeming(EICAST)technology has been developed.Cooling means of spiral coil in this technology is directly related to its service life.Firstly,heat transfer processes of air cooling and spray cooling were compared and analyzed.Secondly,the impacts of water temperature,water flow rate and air flow rate were examined in order to maximize the spray cooling effect.To maintain coil temperature at a low value consistently throughout the entire thermal cycle process of the ladle,a combined cooling mode was finally employed.Numerical simulation was applied to examine the coil temperature variation with different cooling systems and characteristics.Before coil operation,spray cooling is said to be more effective.By controlling the water flow rate and air flow rate,the spray cooling effect is enhanced.However,water temperature has little or no impact when using spray cooling.Air cooling during the secondary refining process and spray cooling prior to coil operation are combined to further lower coil temperature.When the direction of the spray cooling is from bottom to top,the coil temperature is lowered below 165℃.A practical induction coil cooling plan was provided for the EICAST technology’s production process.展开更多
Ambient temperature of induction coil is an important factor to influence the implementation of the electromagnetic induction-controlled automated steel-teeming(EICAST) technology. Meanwhile, it also affects the forma...Ambient temperature of induction coil is an important factor to influence the implementation of the electromagnetic induction-controlled automated steel-teeming(EICAST) technology. Meanwhile, it also affects the formation of Fe–C alloy blocking layer, which determines the length and installation position of induction coil. An experimental platform was designed to imitate actual working conditions in a ladle with the EICAST system. Ambient temperature of induction coil under high-temperature condition was measured to verify the accuracy of numerical result. After containing molten steel for 120 min and steel teeming for 40 min, the ambient temperature on the upper side of induction coil is 791 °C. In addition, the position of blocking layer in a 110 t ladle was measured by sand-collection and steel-pour methods, and the criterion temperatures of blocking layer in numerical simulation process were corrected. When the refining temperature is1600 °C and the containing time of molten steel is 120 min, the thickness of blocking layer is 130 mm, and the distance between the upper surface of blocking layer and the upper surface of nozzle brick is 154 mm. When the criterion temperatures are 919 °C and 428 °C, the numerical results can be used to confirm the position of blocking layer and the installation position of induction coil.展开更多
In the electromagnetic induction-controlled automated steel teeming(EICAST)technology of ladle,the height and location of the blocking layer are critical factors to determine the structure size and installation locati...In the electromagnetic induction-controlled automated steel teeming(EICAST)technology of ladle,the height and location of the blocking layer are critical factors to determine the structure size and installation location of induction coil.And,they are also the key parameters affecting the successful implementation of this new technology.In this paper,the influence of the liquid steel temperature,the holding time and the alloy composition on the height and location of the blocking layer were studied by numerical simulation.The simulation results were verified by 40 t ladle industrial experiments.Moreover,the regulation approach of the blocking layer was determined,and the determination process of coil size and its installation location were also analyzed.The results show that the location of the blocking layer moves down with the increase in the liquid steel temperature and the holding time.The height of the blocking layer decreases with the increase in the liquid steel temperature;however,it increases with the increase in the holding time.The height and location of the blocking layer can be largely adjusted by changing the alloy composition of filling particles in the upper nozzle.When the liquid steel temperature is 1550℃,the holding time is 180 min and the alloy composition is confirmed,the melting layer height is 120 mm,and the blocking layer height is 129 mm,which are beneficial to design and installation of induction coil.These results are very important for the industrial implementation of the EICAST technology.展开更多
The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides...The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.展开更多
Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune ...Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune response,and drug sensitivity.Methods:Data were obtained from The Cancer Genome Atlas(TCGA)-Hepatocellular Carcinoma(LIHC)and Gene Expression Omnibus(GEO,GSE14520 datasets).47 sphingolipid metabolism genes were obtained from the Kyoto Encyclopedia of Genes and Genomes(KEGG)database.After classifying HCC samples using the Non-negative Matrix Factorization(NMF)clustering method,differentially expressed genes were screened.Then,8 risk genes were obtained by univariate analysis,survival random forest reduction and lasso analysis.The expression of 8 risk genes was verified in vitro.Results:8 risk genes were used to construct the Sphingolipid score model.High-Sphingolipid score predicted poor prognosis of HCC patients.Sphingolipid score was associated with immune checkpoints(IL-1B,TLR4,TGFB1,and IL-10),immune cells(Th2,Treg,MDSC,Neutrophil,Fibroblasts and macrophage),and MAPK Cascade.In the High-Sphingolipid score group,a significantly higher proportion of patients with TP53(p53)mutations was significantly higher(56%).Furthermore,patients with a high-Sphingolipid score were predicted to have a higher sensitivity to chemotherapy drugs.In vitro validation showed that compared with normal liver cells LX-2,TRIM47,and S100A9 significantly increased in liver cancer cells Hep G2,MHCC-97H,and Hep3B2.1-7,while SLC1A7,LPCAT1,and CFHR4 significantly decreased.Silencing TRIM47 reduced the proliferation and promoted apoptosis.The levels of ceramide synthesis-related indexes(CERS1,CERS6,CERS5,and SPTLC2)increased,and the ACER3 related to catalytic hydrolysis decreased.Conclusion:We constructed a sphingolipid metabolism-related prognostic signature(Sphingolipid score)based on 8 risk genes.TRIM47 may affect the development of liver cancer by regulating the relevant indicators of ceramide synthesis and catalytic hydrolysis.展开更多
BACKGROUND Esophageal cancer constitutes one of the most aggressive malignant neoplasms associated with poor clinical outcomes.While surgical resection remains the cornerstone of curative intervention,optimization of ...BACKGROUND Esophageal cancer constitutes one of the most aggressive malignant neoplasms associated with poor clinical outcomes.While surgical resection remains the cornerstone of curative intervention,optimization of perioperative care protocols has emerged as an essential strategy to reduce postoperative complications and potentially improve long-term survival rates in patients undergoing esophagectomy.However,substantial debate persists regarding the relative importance of various perioperative risk factors and their impact on post-resection outcomes.AIM To identify perioperative factors affecting prognosis after radical esophagectomy,aiming to improve patient outcomes through targeted interventions.METHODS A retrospective study analyzed 378 patients with esophageal cancer who underwent radical esophagectomy(McKeown,Sweet,or Ivor-Lewis procedures)from January 2022 through December 2023.All operations were performed by experienced surgeons following standardized perioperative protocols.The investigation gathered data on patient demographics,surgical parameters,tumor pathology(using the 8th edition American Joint Committee on Cancer staging system),and survival outcomes.Statistical analyses utilized Kaplan-Meier estimates and Cox proportional hazards modeling,with adjustment for confounding variables.RESULTS Multivariate Cox proportional hazards analysis identified three independent predictors of survival:Tumor-nodemetastasis staging[Hazard ratio(HR)=2.31,95%confidence interval(CI):1.72-3.10,P<0.001],tumor differentiation(moderate:HR=1.46,95%CI:1.02-2.09,P=0.038;poor:HR=2.15,95%CI:1.47-3.14,P<0.001),and extended postoperative analgesic use(>5 days)(HR=1.43,95%CI:1.08-1.89,P=0.012).Kaplan-Meier analysis demonstrated significantly lower overall survival rates in patients requiring analgesics for>5 days compared to≤5 days(P=0.003),with consistent patterns observed for both opioid(P=0.019)and nonsteroidal anti-inflammatory drug use(P=0.028).The extended analgesic group exhibited a higher proportion of elderly patients(48.47%vs 35.57%,P=0.015),while other baseline characteristics and tumor features remained comparable between groups.CONCLUSION Tumor-node-metastasis staging,tumor differentiation,and duration of postoperative analgesic use independently predict survival following radical esophagectomy,underscoring the significance of optimal pain management protocols.展开更多
BACKGROUND Esophageal cancer(EC)is one of the most common malignancies worldwide,and lymph node(LN)metastasis remains one of the leading causes of EC recurrence.Metabolic disorders critically affect cancer progression...BACKGROUND Esophageal cancer(EC)is one of the most common malignancies worldwide,and lymph node(LN)metastasis remains one of the leading causes of EC recurrence.Metabolic disorders critically affect cancer progression,and lipid levels are closely associated with the occurrence of EC and several other tumor types.This study analyzed pretreatment lipid levels to determine their association with LN metastasis.AIM To dissect the possible mechanisms underlying LN metastasis and clarify the prognostic role of lipid profiles in EC.METHODS Serum lipid levels and clinicopathological information were retrospectively collected from 294 patients,and risk factors for LN metastasis were confirmed using a logistic regression model.Latent factors were explored using information from publicly accessible databases and immunofluorescence and immunohistochemical staining techniques.RESULTS High serum levels of low-density lipoprotein(LDL)cholesterol promote LN metastasis in EC,while high-density lipoprotein cholesterol has the opposite role.Information of a public database revealed that LDL receptors LRP5 and LRP6 are highly expressed in ECs,and LRP6 overexpression positively correlated with the infiltration of B lymphocytes and a poor prognosis.Immunofluorescence and immunohistochemical staining revealed that the expression of LRP6 and infiltrated B lymphocytes in patients with≥1 regional LN metastasis,containing N1-3(N+group)were significantly higher than those in the N0 group.LRP6 was also highly expressed in the B lymphocytes of the N+group.There was no difference in CXCL13 expression between the N+and N0 groups.However,CXCR5 expression was significantly higher in the N0 group than in the N+group.CONCLUSION High serum LDL levels can promote LN metastasis in EC,and the mechanisms may be related to LRP6 expression and the infiltration of B lymphocytes.展开更多
This study proposes a double-rough-walled fracture model to represent the natural geometries of rough fractures.The rough surface is generated using a modified successive random additions(SRA)algorithm and the apertur...This study proposes a double-rough-walled fracture model to represent the natural geometries of rough fractures.The rough surface is generated using a modified successive random additions(SRA)algorithm and the aperture distribution during shearing is calculated using a mechanistic model.The shear-flow simulations are performed by directly solving the Navier-Stokes(NS)equations.The results show that the double-rough-walled fracture model can improve the accuracy of fluid flow simulations by approximately 14.99%-19.77%,compared with the commonly used single-rough-walled fracture model.The ratio of flow rate to hydraulic gradient increases by one order of magnitude for fluids in a linear flow regime with increment of shear displacement from 2.2 mm to 2.6 mm.By solving the NS equations,the inertial effect is taken into account and the significant eddies are simulated and numerically visualized,which are not easy to be captured in conventional experiments.The anisotropy of fluid flow in the linear regime during shearing is robustly enhanced as the shearing advances;however,it is either increased or decreased for fluids in the nonlinear flow regime,depending on the geometry of shear-induced void spaces between the two rough walls of the fracture.The present study provides a method to represent the real geometry of fractures during shearing and to simulate fluid flow by directly solving the NS equations,which can be potentially utilized in many applications such as heat and mass transfer,contaminant transport,and coupled hydro-thermo-mechanical processes within rock fractures/fracture networks.展开更多
Electrochemical CO_(2)reduction to formate is a promising approach to store renewable electricity and utilize CO_(2).Tin oxide catalysts are efficient catalysts for this process,while the mechanisms underneath,especia...Electrochemical CO_(2)reduction to formate is a promising approach to store renewable electricity and utilize CO_(2).Tin oxide catalysts are efficient catalysts for this process,while the mechanisms underneath,especially the existence and role of oxidized tin species under CO2 electroreduction conditions remain unclear.In this work,we provide strong evidence on the presence of oxidized tin species on both SnO_(2)and Sn during CO_(2)reduction via in situ surface‐enhanced Raman spectroscopy,while in different nature.Reactivity measurements show similar activity and selectivity to formate production on SnO_(2)and Sn catalysts.Combined analysis of Raman spectra and reactivity results suggests that Sn(IV)and Sn(II)oxide species are unlikely the catalytic species in CO_(2)electroreduction to formate.展开更多
Homogenization of physical properties and the chemical composition through the control of liquid metal flow is essentialduring the continuous casting production of billets. This work was aimed at obtaining improved fi...Homogenization of physical properties and the chemical composition through the control of liquid metal flow is essentialduring the continuous casting production of billets. This work was aimed at obtaining improved finished products viacontinuous casting that implements two magnetic fields. These fields were realized via two electromagnetic stirringprocesses implemented in a single process： one in the nozzle and one in the mold. The qualitative effects of applyingdouble electromagnetic stirring （EMS） were verified through numerical simulation of 178 mm × 178 mm square billetsexposed to double electromagnetic fields during the continuous casting process. The accuracy of the numerical calculationswas verified via physical experiments. In addition, the final simulation results were compared with the intermediate results,to determine the true effects of different EMS on the metal flow in the mold. The results revealed that casting using EMSwith different directions of magnetic field in the mold and the nozzle has the best effect on the distribution of the fluid flowand minimal influence on the stability of the meniscus and yields the minimum metal-jet penetration into the mold.展开更多
Feather, as a by-product of the poultry industry, has long been treated as a solid waste, which causes environ- mental and economic problems. In this work, the hydrolyzed feather keratin （HFK） was extracted from the...Feather, as a by-product of the poultry industry, has long been treated as a solid waste, which causes environ- mental and economic problems. In this work, the hydrolyzed feather keratin （HFK） was extracted from the chicken feather using a cost-effective method of alkali-extraction and acid-precipitation by applying urea and sodium sulfide. The aim was development and characterization of the eco-friendly films based on the HFK with variable glycerol contents by a thermoplastic process. The thermal analysis showed that high temperature and high pres- sure improved the compatibility between the glycerol and the HFI（ molecules. Also it was shown that the addi- tion of water is necessary in the hot-pressing process of films, The FT-IR analysis indicated that the formation of the new hydrogen bonds between HFK and glycerol. By increasing the glycerol content, the film tensile strength （orb ） decreases from 10,5 MPa to 5.7 MPa and the solubility increases from 15.3% to 20.9%, while the elongation at break （εb） achieves the maximum value of 63,8% for the film with 35% glycerol. The swelling was just below 16.9% at 25 ℃ for 24 h, suggesting a good stability of the films in water. The water vapor permeability （WVP） varied between 3.02 x 10 ^10g. m 2. s-1 . pa-1 and 4.11 x 10-10g · m-2 · s-1 · Pa-1 for the films with 20%and 40% glycerol, respectively. The HFK film was uniform, translucent and tough, which could be used in packaging and agricultural field.展开更多
An experimental and numerical study was carried out to investigate the solute removal process through a large-scale fracture plane considering different flow paths and hydraulic head differences.The visualization tech...An experimental and numerical study was carried out to investigate the solute removal process through a large-scale fracture plane considering different flow paths and hydraulic head differences.The visualization techniques were utilized in the experiment to capture the removal process images,which were then transferred to binary images.The variations in dimensionless concentration,which is defined as saturation of solute phase,were analyzed.With increasing hydraulic head difference,the speed of solute removal increases and the dimensionless concentration decreases.The flow paths result in different solute distribution patterns and different mechanisms for solute removal such as advection and diffusion,thus the curves of dimensionless concentration versus time are different.The dimensionless concentration over time decreases from approximately 1,which is smaller than 1 due to the existence of bubbles,to approximately 0,which is larger than 0 because the folds of the background are dealt as“solute”.A significant longer time is needed to achieve a certain fixed dimensionless concentration for a smaller hydraulic head difference.With the finite element software COMSOL multiphysics,the solute removal process,flow velocity fields,flow streamlines,as well as the hydraulic pressure fields were analyzed,which shows a good consistency with the experimental results.In practical engineering,when the solute pollutes the underground environment,the removal ability can be more significantly enforced by immediately applying a larger hydraulic head difference along a longer distance between the inlet and outlet boundaries.展开更多
By introducing the pyrazole moiety into the 5-position of 1,3,4-oxadiazole,a series of novel 2-（thioether/sulfone）-5-pyrazolyl-l,3,4-oxadiazole derivatives were synthesized.Preliminary bioassays suggested that targe...By introducing the pyrazole moiety into the 5-position of 1,3,4-oxadiazole,a series of novel 2-（thioether/sulfone）-5-pyrazolyl-l,3,4-oxadiazole derivatives were synthesized.Preliminary bioassays suggested that target compounds exhibited appreciable activity against pathogenic bacteria Xanthomonas oryzae pv.oryzae（Xoo） and five phytopathogenic fungi in vitro.Among them,the half-maximal effective concentration（EC_（50）） values of 6c,7a,7b and 7c against Xoo were within 16.6 μg/mL and 65.7 μg/mL,which were better than those of commercial agricultural antibacterial bismerthiazol（92.6 μg/mL） and thiodiazole copper（121.8 μg/mL）.While compounds 7a,7b,and 7c exerted comprehensive antifungal activity toward five plant fungi,which were comparable with that of hymexazol.The results demonstrated that this kind of compounds can be further studied and developed as promising antifungal and antibacterial agents.展开更多
In this study,carboxymethylation,which introduces carboxyl groups to hydroxyl sites in pulp fibers,was used as a pretreatment before mechanical nanofibrillation.The carboxyl group content of the pulp fibers was greatl...In this study,carboxymethylation,which introduces carboxyl groups to hydroxyl sites in pulp fibers,was used as a pretreatment before mechanical nanofibrillation.The carboxyl group content of the pulp fibers was greatly affected by the dosage of chloroacetic acid and the reaction temperature.During the following fibrillation process,it was found that pulp fibers with higher carboxyl group content exhibited higher water holding capacities and smaller dimensions.A more homogenous structure with a higher amount of individual fibrils was also observed in FE-SEM images of pulp fibers with high carboxyl group content.This can be explained by a high ionic group content in the fiber wall resulting in lower delamination resistance,making the fibrils easier to separate.Carboxymethylation pretreatment as a facilitator of fibrillation in cellulosic pulps is an efficient way to obtain cellulose nanofibrils and consequently decrease the energy consumption of the process.展开更多
An efficient synthesis of chromeno[4,3-b]quinoline derivatives via one-pot,four-component reaction of 4-hydroxycoumarin, formaldehyde,cyclohexanedione,ammonium ceric nitrate under microwave irradiation was accomplishe...An efficient synthesis of chromeno[4,3-b]quinoline derivatives via one-pot,four-component reaction of 4-hydroxycoumarin, formaldehyde,cyclohexanedione,ammonium ceric nitrate under microwave irradiation was accomplished.The structures of these compounds were unambiguously confirmed by single crystal X-ray diffraction.Furthermore,the anti-AChE activities of these compounds in vitro were investigated at concentrations of 20μM and 50μM by using a standard Ellman's method.The relationship of inhibitory activities and structures of these chromeno [4,3-b]quinolines was also systematically studied.Of all the compounds investigated,4ag emerged as the most potent AChE inhibitor with IC50 values of 5.63μM,and it might be used as potent lead for the development anti-AChE agents.Moreover,molecular modelling was conducted to understand the optimal interaction of AChE with these types of compounds.展开更多
In this paper, the totally non-positive matrix is introduced. The totally non-positive completion asks which partial totally non-positive matrices have a completion to a totally non-positive matrix. This problem has. ...In this paper, the totally non-positive matrix is introduced. The totally non-positive completion asks which partial totally non-positive matrices have a completion to a totally non-positive matrix. This problem has. in general, a negative answer. Therefore, our question is for what kind of labeled graphs G each partial totally non-positive matrix whose associated graph is G has a totally non-positive completion? If G is not a monotonically labeled graph or monotonically labeled cycle, we give necessary and sufficient conditions that guarantee the existence of the desired completion.展开更多
The fluid-structure interaction of the oscillating bubble and floating body with circular hole is essentially the nonlinear coupling problem among the incomplete movable boundary,free surface and bubble.This problem i...The fluid-structure interaction of the oscillating bubble and floating body with circular hole is essentially the nonlinear coupling problem among the incomplete movable boundary,free surface and bubble.This problem is particularly complicated in bubble dynamics.Combined with the volume of fluid method,the Eulerian finite element method is employed to deal with the fluid movement.Based on the improved penalty immersed boundary method,the transient axisymmetric numerical model is established in this paper,considering the fluid-structure interaction effect.The results of simulation are consistent with those of the electric discharge bubble experiment and explosion experiment.Subsequently,considering the influence of the hole size,floating body density,explosive location,and buoyancy,this complex fluid-structure interaction problem is analyzed systematically.Through numerical simulation,we get some new conclusions.When the radius of the hole Rh less than the maximum radius of the oscillating bubble,the changes in the whole system are incredibly intense,and the free surface crushing will emerge.The energy of the bubble acts more on the radial direction of the floating body,when the explosive location parameter is small.When the floating body has the same density as the water,the multiple spike skirt is displayed vividly.And the buoyancy of fluid can produce a lifting effect on the floating body.展开更多
基金supported by the Startup Foundation of Shenyang Agriculture University(No.X2023050)the Fundamental Research Funds for the Central Universities(No.N2209006)the National Natural Science Foundation of China(No.U22A20173).
文摘To address the current issues with the conventional slide gate system utilized in the steel teeming process,a unique electromagnetic induction controlled automated steel teeming(EICAST)technology has been developed.Cooling means of spiral coil in this technology is directly related to its service life.Firstly,heat transfer processes of air cooling and spray cooling were compared and analyzed.Secondly,the impacts of water temperature,water flow rate and air flow rate were examined in order to maximize the spray cooling effect.To maintain coil temperature at a low value consistently throughout the entire thermal cycle process of the ladle,a combined cooling mode was finally employed.Numerical simulation was applied to examine the coil temperature variation with different cooling systems and characteristics.Before coil operation,spray cooling is said to be more effective.By controlling the water flow rate and air flow rate,the spray cooling effect is enhanced.However,water temperature has little or no impact when using spray cooling.Air cooling during the secondary refining process and spray cooling prior to coil operation are combined to further lower coil temperature.When the direction of the spray cooling is from bottom to top,the coil temperature is lowered below 165℃.A practical induction coil cooling plan was provided for the EICAST technology’s production process.
基金financially supported by the National Natural Science Foundation of China (Grant No. U1560207)
文摘Ambient temperature of induction coil is an important factor to influence the implementation of the electromagnetic induction-controlled automated steel-teeming(EICAST) technology. Meanwhile, it also affects the formation of Fe–C alloy blocking layer, which determines the length and installation position of induction coil. An experimental platform was designed to imitate actual working conditions in a ladle with the EICAST system. Ambient temperature of induction coil under high-temperature condition was measured to verify the accuracy of numerical result. After containing molten steel for 120 min and steel teeming for 40 min, the ambient temperature on the upper side of induction coil is 791 °C. In addition, the position of blocking layer in a 110 t ladle was measured by sand-collection and steel-pour methods, and the criterion temperatures of blocking layer in numerical simulation process were corrected. When the refining temperature is1600 °C and the containing time of molten steel is 120 min, the thickness of blocking layer is 130 mm, and the distance between the upper surface of blocking layer and the upper surface of nozzle brick is 154 mm. When the criterion temperatures are 919 °C and 428 °C, the numerical results can be used to confirm the position of blocking layer and the installation position of induction coil.
基金financially supported by the National Natural Science Foundation of China(Grant No.U1560207)the Liaoning Innovative Research Team in University(Grant No.LT2017011)
文摘In the electromagnetic induction-controlled automated steel teeming(EICAST)technology of ladle,the height and location of the blocking layer are critical factors to determine the structure size and installation location of induction coil.And,they are also the key parameters affecting the successful implementation of this new technology.In this paper,the influence of the liquid steel temperature,the holding time and the alloy composition on the height and location of the blocking layer were studied by numerical simulation.The simulation results were verified by 40 t ladle industrial experiments.Moreover,the regulation approach of the blocking layer was determined,and the determination process of coil size and its installation location were also analyzed.The results show that the location of the blocking layer moves down with the increase in the liquid steel temperature and the holding time.The height of the blocking layer decreases with the increase in the liquid steel temperature;however,it increases with the increase in the holding time.The height and location of the blocking layer can be largely adjusted by changing the alloy composition of filling particles in the upper nozzle.When the liquid steel temperature is 1550℃,the holding time is 180 min and the alloy composition is confirmed,the melting layer height is 120 mm,and the blocking layer height is 129 mm,which are beneficial to design and installation of induction coil.These results are very important for the industrial implementation of the EICAST technology.
基金supported by the National Natural Science Foundation of China(Nos.12125509,12222514,11961141003,and 12005304)National Key Research and Development Project(No.2022YFA1602301)+1 种基金CAST Young Talent Support Planthe CNNC Science Fund for Talented Young Scholars Continuous support for basic scientific research projects。
文摘The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.
基金The work was supported by funds from The Science and Technology Project of Hangzhou City(Agriculture and Social Development,No.2016007)&(Agriculture and Social Development,No.20201231Y131)&(Social Development,No.20140633B57)The Science and Technology Project of Yuhang District,Hangzhou City(Nos.2017002&2014003)+2 种基金The Health Science and Technology Project of Hangzhou City(No.2015B32)Zhejiang Provincial Natural Science Foundation of China under Grant(No.LTGY23H160006)The Health Science and Technology Project of Zhejiang Province(No.2023XY009).
文摘Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune response,and drug sensitivity.Methods:Data were obtained from The Cancer Genome Atlas(TCGA)-Hepatocellular Carcinoma(LIHC)and Gene Expression Omnibus(GEO,GSE14520 datasets).47 sphingolipid metabolism genes were obtained from the Kyoto Encyclopedia of Genes and Genomes(KEGG)database.After classifying HCC samples using the Non-negative Matrix Factorization(NMF)clustering method,differentially expressed genes were screened.Then,8 risk genes were obtained by univariate analysis,survival random forest reduction and lasso analysis.The expression of 8 risk genes was verified in vitro.Results:8 risk genes were used to construct the Sphingolipid score model.High-Sphingolipid score predicted poor prognosis of HCC patients.Sphingolipid score was associated with immune checkpoints(IL-1B,TLR4,TGFB1,and IL-10),immune cells(Th2,Treg,MDSC,Neutrophil,Fibroblasts and macrophage),and MAPK Cascade.In the High-Sphingolipid score group,a significantly higher proportion of patients with TP53(p53)mutations was significantly higher(56%).Furthermore,patients with a high-Sphingolipid score were predicted to have a higher sensitivity to chemotherapy drugs.In vitro validation showed that compared with normal liver cells LX-2,TRIM47,and S100A9 significantly increased in liver cancer cells Hep G2,MHCC-97H,and Hep3B2.1-7,while SLC1A7,LPCAT1,and CFHR4 significantly decreased.Silencing TRIM47 reduced the proliferation and promoted apoptosis.The levels of ceramide synthesis-related indexes(CERS1,CERS6,CERS5,and SPTLC2)increased,and the ACER3 related to catalytic hydrolysis decreased.Conclusion:We constructed a sphingolipid metabolism-related prognostic signature(Sphingolipid score)based on 8 risk genes.TRIM47 may affect the development of liver cancer by regulating the relevant indicators of ceramide synthesis and catalytic hydrolysis.
文摘BACKGROUND Esophageal cancer constitutes one of the most aggressive malignant neoplasms associated with poor clinical outcomes.While surgical resection remains the cornerstone of curative intervention,optimization of perioperative care protocols has emerged as an essential strategy to reduce postoperative complications and potentially improve long-term survival rates in patients undergoing esophagectomy.However,substantial debate persists regarding the relative importance of various perioperative risk factors and their impact on post-resection outcomes.AIM To identify perioperative factors affecting prognosis after radical esophagectomy,aiming to improve patient outcomes through targeted interventions.METHODS A retrospective study analyzed 378 patients with esophageal cancer who underwent radical esophagectomy(McKeown,Sweet,or Ivor-Lewis procedures)from January 2022 through December 2023.All operations were performed by experienced surgeons following standardized perioperative protocols.The investigation gathered data on patient demographics,surgical parameters,tumor pathology(using the 8th edition American Joint Committee on Cancer staging system),and survival outcomes.Statistical analyses utilized Kaplan-Meier estimates and Cox proportional hazards modeling,with adjustment for confounding variables.RESULTS Multivariate Cox proportional hazards analysis identified three independent predictors of survival:Tumor-nodemetastasis staging[Hazard ratio(HR)=2.31,95%confidence interval(CI):1.72-3.10,P<0.001],tumor differentiation(moderate:HR=1.46,95%CI:1.02-2.09,P=0.038;poor:HR=2.15,95%CI:1.47-3.14,P<0.001),and extended postoperative analgesic use(>5 days)(HR=1.43,95%CI:1.08-1.89,P=0.012).Kaplan-Meier analysis demonstrated significantly lower overall survival rates in patients requiring analgesics for>5 days compared to≤5 days(P=0.003),with consistent patterns observed for both opioid(P=0.019)and nonsteroidal anti-inflammatory drug use(P=0.028).The extended analgesic group exhibited a higher proportion of elderly patients(48.47%vs 35.57%,P=0.015),while other baseline characteristics and tumor features remained comparable between groups.CONCLUSION Tumor-node-metastasis staging,tumor differentiation,and duration of postoperative analgesic use independently predict survival following radical esophagectomy,underscoring the significance of optimal pain management protocols.
文摘BACKGROUND Esophageal cancer(EC)is one of the most common malignancies worldwide,and lymph node(LN)metastasis remains one of the leading causes of EC recurrence.Metabolic disorders critically affect cancer progression,and lipid levels are closely associated with the occurrence of EC and several other tumor types.This study analyzed pretreatment lipid levels to determine their association with LN metastasis.AIM To dissect the possible mechanisms underlying LN metastasis and clarify the prognostic role of lipid profiles in EC.METHODS Serum lipid levels and clinicopathological information were retrospectively collected from 294 patients,and risk factors for LN metastasis were confirmed using a logistic regression model.Latent factors were explored using information from publicly accessible databases and immunofluorescence and immunohistochemical staining techniques.RESULTS High serum levels of low-density lipoprotein(LDL)cholesterol promote LN metastasis in EC,while high-density lipoprotein cholesterol has the opposite role.Information of a public database revealed that LDL receptors LRP5 and LRP6 are highly expressed in ECs,and LRP6 overexpression positively correlated with the infiltration of B lymphocytes and a poor prognosis.Immunofluorescence and immunohistochemical staining revealed that the expression of LRP6 and infiltrated B lymphocytes in patients with≥1 regional LN metastasis,containing N1-3(N+group)were significantly higher than those in the N0 group.LRP6 was also highly expressed in the B lymphocytes of the N+group.There was no difference in CXCL13 expression between the N+and N0 groups.However,CXCR5 expression was significantly higher in the N0 group than in the N+group.CONCLUSION High serum LDL levels can promote LN metastasis in EC,and the mechanisms may be related to LRP6 expression and the infiltration of B lymphocytes.
基金partially funded by National Natural Science Foundation of China(Grant Nos.51979272 and 51709260)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20170276).
文摘This study proposes a double-rough-walled fracture model to represent the natural geometries of rough fractures.The rough surface is generated using a modified successive random additions(SRA)algorithm and the aperture distribution during shearing is calculated using a mechanistic model.The shear-flow simulations are performed by directly solving the Navier-Stokes(NS)equations.The results show that the double-rough-walled fracture model can improve the accuracy of fluid flow simulations by approximately 14.99%-19.77%,compared with the commonly used single-rough-walled fracture model.The ratio of flow rate to hydraulic gradient increases by one order of magnitude for fluids in a linear flow regime with increment of shear displacement from 2.2 mm to 2.6 mm.By solving the NS equations,the inertial effect is taken into account and the significant eddies are simulated and numerically visualized,which are not easy to be captured in conventional experiments.The anisotropy of fluid flow in the linear regime during shearing is robustly enhanced as the shearing advances;however,it is either increased or decreased for fluids in the nonlinear flow regime,depending on the geometry of shear-induced void spaces between the two rough walls of the fracture.The present study provides a method to represent the real geometry of fractures during shearing and to simulate fluid flow by directly solving the NS equations,which can be potentially utilized in many applications such as heat and mass transfer,contaminant transport,and coupled hydro-thermo-mechanical processes within rock fractures/fracture networks.
文摘Electrochemical CO_(2)reduction to formate is a promising approach to store renewable electricity and utilize CO_(2).Tin oxide catalysts are efficient catalysts for this process,while the mechanisms underneath,especially the existence and role of oxidized tin species under CO2 electroreduction conditions remain unclear.In this work,we provide strong evidence on the presence of oxidized tin species on both SnO_(2)and Sn during CO_(2)reduction via in situ surface‐enhanced Raman spectroscopy,while in different nature.Reactivity measurements show similar activity and selectivity to formate production on SnO_(2)and Sn catalysts.Combined analysis of Raman spectra and reactivity results suggests that Sn(IV)and Sn(II)oxide species are unlikely the catalytic species in CO_(2)electroreduction to formate.
基金financial support from the National Natural Science Foundation of China(Nos.U1560207and U51504057)the National Key R&D Program of China:Upgrading and Industrialization of Key Basic Material Technology(No.2017YFB0304400)
文摘Homogenization of physical properties and the chemical composition through the control of liquid metal flow is essentialduring the continuous casting production of billets. This work was aimed at obtaining improved finished products viacontinuous casting that implements two magnetic fields. These fields were realized via two electromagnetic stirringprocesses implemented in a single process： one in the nozzle and one in the mold. The qualitative effects of applyingdouble electromagnetic stirring （EMS） were verified through numerical simulation of 178 mm × 178 mm square billetsexposed to double electromagnetic fields during the continuous casting process. The accuracy of the numerical calculationswas verified via physical experiments. In addition, the final simulation results were compared with the intermediate results,to determine the true effects of different EMS on the metal flow in the mold. The results revealed that casting using EMSwith different directions of magnetic field in the mold and the nozzle has the best effect on the distribution of the fluid flowand minimal influence on the stability of the meniscus and yields the minimum metal-jet penetration into the mold.
基金Supported by the National Natural Science Foundation of China(21176269,31371880,31401526)Higher School Science and Technology Innovation Project of Guangdong Province(2013KJCX0102)Science and Technology Plan Project of Guangdong Province(2013B010403029)
文摘Feather, as a by-product of the poultry industry, has long been treated as a solid waste, which causes environ- mental and economic problems. In this work, the hydrolyzed feather keratin （HFK） was extracted from the chicken feather using a cost-effective method of alkali-extraction and acid-precipitation by applying urea and sodium sulfide. The aim was development and characterization of the eco-friendly films based on the HFK with variable glycerol contents by a thermoplastic process. The thermal analysis showed that high temperature and high pres- sure improved the compatibility between the glycerol and the HFI（ molecules. Also it was shown that the addi- tion of water is necessary in the hot-pressing process of films, The FT-IR analysis indicated that the formation of the new hydrogen bonds between HFK and glycerol. By increasing the glycerol content, the film tensile strength （orb ） decreases from 10,5 MPa to 5.7 MPa and the solubility increases from 15.3% to 20.9%, while the elongation at break （εb） achieves the maximum value of 63,8% for the film with 35% glycerol. The swelling was just below 16.9% at 25 ℃ for 24 h, suggesting a good stability of the films in water. The water vapor permeability （WVP） varied between 3.02 x 10 ^10g. m 2. s-1 . pa-1 and 4.11 x 10-10g · m-2 · s-1 · Pa-1 for the films with 20%and 40% glycerol, respectively. The HFK film was uniform, translucent and tough, which could be used in packaging and agricultural field.
基金supported by National Natural Science Foundation of China(Nos.51979272,51904290,51979156)the Natural Science Foundation of Jiangsu Province,China(No.BK20180663)State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology,China(No.SKLGDUEK1906).
文摘An experimental and numerical study was carried out to investigate the solute removal process through a large-scale fracture plane considering different flow paths and hydraulic head differences.The visualization techniques were utilized in the experiment to capture the removal process images,which were then transferred to binary images.The variations in dimensionless concentration,which is defined as saturation of solute phase,were analyzed.With increasing hydraulic head difference,the speed of solute removal increases and the dimensionless concentration decreases.The flow paths result in different solute distribution patterns and different mechanisms for solute removal such as advection and diffusion,thus the curves of dimensionless concentration versus time are different.The dimensionless concentration over time decreases from approximately 1,which is smaller than 1 due to the existence of bubbles,to approximately 0,which is larger than 0 because the folds of the background are dealt as“solute”.A significant longer time is needed to achieve a certain fixed dimensionless concentration for a smaller hydraulic head difference.With the finite element software COMSOL multiphysics,the solute removal process,flow velocity fields,flow streamlines,as well as the hydraulic pressure fields were analyzed,which shows a good consistency with the experimental results.In practical engineering,when the solute pollutes the underground environment,the removal ability can be more significantly enforced by immediately applying a larger hydraulic head difference along a longer distance between the inlet and outlet boundaries.
基金the financial support of the Key Technologies R&D Program (No. 2014BAD23B01)National Natural Science Foundation of China (No. 21372052)+1 种基金the Research Project of Chinese Ministry of Education (Nos. 213033A, 20135201110005)Scientific Research Foundation for the Introduced Talents of Guizhou University (2015-34)
文摘By introducing the pyrazole moiety into the 5-position of 1,3,4-oxadiazole,a series of novel 2-（thioether/sulfone）-5-pyrazolyl-l,3,4-oxadiazole derivatives were synthesized.Preliminary bioassays suggested that target compounds exhibited appreciable activity against pathogenic bacteria Xanthomonas oryzae pv.oryzae（Xoo） and five phytopathogenic fungi in vitro.Among them,the half-maximal effective concentration（EC_（50）） values of 6c,7a,7b and 7c against Xoo were within 16.6 μg/mL and 65.7 μg/mL,which were better than those of commercial agricultural antibacterial bismerthiazol（92.6 μg/mL） and thiodiazole copper（121.8 μg/mL）.While compounds 7a,7b,and 7c exerted comprehensive antifungal activity toward five plant fungi,which were comparable with that of hymexazol.The results demonstrated that this kind of compounds can be further studied and developed as promising antifungal and antibacterial agents.
基金financial support from the National Key Research and Development Program of China (Grant No.2017YFB0307900)the National Natural Science Foundation of China (Grant No.31470602,31670595,31770628)the Taishan Scholars Program
文摘In this study,carboxymethylation,which introduces carboxyl groups to hydroxyl sites in pulp fibers,was used as a pretreatment before mechanical nanofibrillation.The carboxyl group content of the pulp fibers was greatly affected by the dosage of chloroacetic acid and the reaction temperature.During the following fibrillation process,it was found that pulp fibers with higher carboxyl group content exhibited higher water holding capacities and smaller dimensions.A more homogenous structure with a higher amount of individual fibrils was also observed in FE-SEM images of pulp fibers with high carboxyl group content.This can be explained by a high ionic group content in the fiber wall resulting in lower delamination resistance,making the fibrils easier to separate.Carboxymethylation pretreatment as a facilitator of fibrillation in cellulosic pulps is an efficient way to obtain cellulose nanofibrils and consequently decrease the energy consumption of the process.
基金NSFC(Grant No.81773557,81573279,81373255)Major Project of Technology Innovation Program of Hubei Province(Grant No.2016ACA126)+1 种基金NSFHP(Grant No.2017CFA024)and the Fun damental Research Funds for the Central Universities of China(Grant No.2042017kf0288)
文摘An efficient synthesis of chromeno[4,3-b]quinoline derivatives via one-pot,four-component reaction of 4-hydroxycoumarin, formaldehyde,cyclohexanedione,ammonium ceric nitrate under microwave irradiation was accomplished.The structures of these compounds were unambiguously confirmed by single crystal X-ray diffraction.Furthermore,the anti-AChE activities of these compounds in vitro were investigated at concentrations of 20μM and 50μM by using a standard Ellman's method.The relationship of inhibitory activities and structures of these chromeno [4,3-b]quinolines was also systematically studied.Of all the compounds investigated,4ag emerged as the most potent AChE inhibitor with IC50 values of 5.63μM,and it might be used as potent lead for the development anti-AChE agents.Moreover,molecular modelling was conducted to understand the optimal interaction of AChE with these types of compounds.
基金The work was supported by the National Science Foundation of China (10571146).
文摘In this paper, the totally non-positive matrix is introduced. The totally non-positive completion asks which partial totally non-positive matrices have a completion to a totally non-positive matrix. This problem has. in general, a negative answer. Therefore, our question is for what kind of labeled graphs G each partial totally non-positive matrix whose associated graph is G has a totally non-positive completion? If G is not a monotonically labeled graph or monotonically labeled cycle, we give necessary and sufficient conditions that guarantee the existence of the desired completion.
基金The National Key R and D Program of China(2018YFC0308900)the National Natural Science Foundation of China(Grant No.51879050)+1 种基金the Industrial Technology Development Program(Grant No.JCKY2018604C010)the China Postdoctoral Science Foundation(Grant Nos.2016M600244,2018T110271).
文摘The fluid-structure interaction of the oscillating bubble and floating body with circular hole is essentially the nonlinear coupling problem among the incomplete movable boundary,free surface and bubble.This problem is particularly complicated in bubble dynamics.Combined with the volume of fluid method,the Eulerian finite element method is employed to deal with the fluid movement.Based on the improved penalty immersed boundary method,the transient axisymmetric numerical model is established in this paper,considering the fluid-structure interaction effect.The results of simulation are consistent with those of the electric discharge bubble experiment and explosion experiment.Subsequently,considering the influence of the hole size,floating body density,explosive location,and buoyancy,this complex fluid-structure interaction problem is analyzed systematically.Through numerical simulation,we get some new conclusions.When the radius of the hole Rh less than the maximum radius of the oscillating bubble,the changes in the whole system are incredibly intense,and the free surface crushing will emerge.The energy of the bubble acts more on the radial direction of the floating body,when the explosive location parameter is small.When the floating body has the same density as the water,the multiple spike skirt is displayed vividly.And the buoyancy of fluid can produce a lifting effect on the floating body.
