In this article,we consider a discrete right-definite Sturm-Liouville problems with two squared eigenparameter-dependent boundary conditions.By constructing some new Lagrange-type identities and two fundamental functi...In this article,we consider a discrete right-definite Sturm-Liouville problems with two squared eigenparameter-dependent boundary conditions.By constructing some new Lagrange-type identities and two fundamental functions,we obtain not only the existence,the simplicity,and the interlacing properties of the real eigenvalues,but also the oscillation properties,orthogonality of the eigenfunctions,and the expansion theorem.Finally,we also give a computation scheme for computing eigenvalues and eigenfunctions of specific eigenvalue problems.展开更多
The flow in a liquid falling film is predominantly laminar,and the liquid-side mass transfer is limited by molecular diffusion.The effective way to enhance the mass transfer is to improve the liquid film flow behavior...The flow in a liquid falling film is predominantly laminar,and the liquid-side mass transfer is limited by molecular diffusion.The effective way to enhance the mass transfer is to improve the liquid film flow behavior.The falling film behaviors of water,ethanol and ethylene glycol in nine different wavy microchannels were simulated by Computational Fluid Dynamics.The simulation results show that the falling film thickness exhibits a waveform distribution resulting in a resonance phenomenon along the wavy microchannel.The fluctuation of liquid film surface increases the gas-liquid interface area,and the internal eddy flow inside the liquid film also improves the turbulence of liquid film,the gas-liquid mass transfer in falling film microchannels is intensified.Compared with flat microchannel,the CO_(2) absorption efficiency in water in the wavy microchannel is improved over 41%.Prediction models of liquid film amplitude and average liquid film thickness were established respectively.展开更多
Perovskite-based materials can be widely used in the aerospace and transportation field. Perovskite man-ganese oxides La0.7Sr0.3MnO3 （LSMO） thin films were grown on LaAlO3 （100） and Si （100） single crystal sub-s...Perovskite-based materials can be widely used in the aerospace and transportation field. Perovskite man-ganese oxides La0.7Sr0.3MnO3 （LSMO） thin films were grown on LaAlO3 （100） and Si （100） single crystal sub-strates by the polymer-assisted chemical solution deposi-tion （PACSD） method. Electronic transport behavior, microstructure, and magnetoresistance （MR） of LSMO thin films on different substrates were investigated. The resis-tance of LSMO films fabricated on LaAlO3 substrates is smaller than that on the Si substrates. The magnetic field reduces resistance of LSMO films both on Si and LAO in the wide temperature region, when the insulator-metal transition temperature shifts to higher temperature. The low-field magnetoresistance of LSMO films on Si in low temperature range at 1 T is larger than that of LSMO films on LAO. However, the MR of LSMO film on LAO films at room-temperature is about 5.17%. The thin films are smooth and dense with uniform nanocrystal size grain. These results demonstrate that PACSD is an effective technique for producing high quality LSMO films, which is significant to improve the magnetic properties and the application of automotive sensor.展开更多
Background:Consumption of resistant starch(RS)has been associated with various intestinal and systemic health benefits,but knowledge of its effects on intestinal health and inflammatory response in stressed birds is l...Background:Consumption of resistant starch(RS)has been associated with various intestinal and systemic health benefits,but knowledge of its effects on intestinal health and inflammatory response in stressed birds is limited.Here,we examined how dietary RS supplementation from 12%raw potato starch(RPS)modulated inflammatory severity induced by lipopolysaccharide(LPS)in meat ducks.Results:LPS administration at 14,16,and 18 d(chronic challenge)decreased body weight(BW)and glucagon-like peptide 1 receptor(GLP-1R)level with higher intestinal permeability and inflammation,evident by higher proinflammatory cytokine levels.Dietary 12%RPS supplementation enhanced Claudin-1 and GLP-1R expression,along with lower levels of inflammatory factors in both ileum and serum.Microbiome analysis showed that RS treatment shifted microbial structure reflected by enriched the proportion of Firmicutes,Bifidobacterium,Ruminococcus,etc.Dietary RS addition also significantly increased the concentrations of propionate and butyrate during chronic LPS challenge.Furthermore,response to acute challenge,the ducks received 2 mg/kg BW LPS at 14 d had higher concentrations of serum endotoxins and inflammatory cytokines,as well as upregulated transcription of toll like receptor 4(TLR4)in ileum when compared to control birds.Analogous to GLP-1 agonist liraglutide,dietary RS addition decreased endotoxins and inflammation cytokines,whereas it upregulated the GLP-1 synthesis related genes expression.Meanwhile,dietary RS supplementation suppressed the acute LPS challenge-induced TLR4 transcription.Conclusions:These data suggest that dietary 12%RPS supplementation could attenuate the LPS-induced inflammation as well as intestinal injury of meat ducks,which might involve in the alteration in gut microbiota,SCFAs production and the signaling pathways of TLR4 and GLP-1/GLP-1R.展开更多
Image reconstruction for list-mode time-of-flight(TOF)positron emission tomography(PET)can be achieved by analytic algorithms.The backprojection filtering(BPF)algorithm is an efficient algorithm for this task.The conv...Image reconstruction for list-mode time-of-flight(TOF)positron emission tomography(PET)can be achieved by analytic algorithms.The backprojection filtering(BPF)algorithm is an efficient algorithm for this task.The conventional noise control method for analytic image reconstruction is the use of a stationary lowpass filter,which does not model the Poisson noise properly.This study proposes a nonstationary filter for Poisson noise control.The filter is implemented in the spatial domain in a form similar to convolution.展开更多
A specific, precise and accurate ion-pair HPLC-UV method has been developed and validated for simultaneous determination of phosphocreatine (PCr), and its metabolite creatine (Cr) as well as related ATP in plasma and ...A specific, precise and accurate ion-pair HPLC-UV method has been developed and validated for simultaneous determination of phosphocreatine (PCr), and its metabolite creatine (Cr) as well as related ATP in plasma and red blood cell (RBC) of rabbits. After addition of TMP as IS, the samples were deproteinized with 6% PCA. The analytes were separated on a Kromasil C18 column using a tertiary gradient mobile phase composed of buffer A (0.2% KH2PO4 + 0.08% tetrabutyl ammonium hydrogen sulphate, pH 3.0), buffer B (buffer A adjusted to pH 7.5 with 1 mol/L NaOH) and MeOH. Detection wavelengths were set at 210 nm for PCr and Cr and 260 nm for ATP and TMP. Some blank samples were initially run for baseline subtraction. The linear detection responses were obtained for PCr concentration over a range of 10 - 7500 mg/ml (plasma) and 5 - 2500 mg/ml (RBC) and for both Cr and ATP concentrations of 10 - 1500 mg/ml (plasma) and 5 - 750 mg/ml (RBC) (r > 0.99). The QC samples of 3 analytes showed intra-day and inter-day precisions (RSD) of - 107%. The method was successfully used to simultaneously determine plasma and RBC concentrations of the 3 analytes and to study pharmacokinetics after iv administration of PCr to rabbits.展开更多
Water vapor nucleation on particle's surface plays an important role in dust removal,cloud formation,and particle measurement.However,the selectivity of nucleation sites and the nucleation characteristic of water ...Water vapor nucleation on particle's surface plays an important role in dust removal,cloud formation,and particle measurement.However,the selectivity of nucleation sites and the nucleation characteristic of water molecule on the particle's surface are still unclear,especially for the aggregated particles.In this paper,the effects of particle wettability and aggregation modes on the selectivity of nucleation sites and the nucleation characteristics were investigated using molecular dynamics simulation.The results were compared with our earlier experimental findings.It illustrates how the contact angle of clusters,the growth velocity,and the growth duration are all influenced by the interaction coefficient between water and particles.Moreover,the nucleation sites of water molecules on the particle aggregation surface exhibit a definite selectivity.The primary indicator of this selectivity is the preferential nucleation of water molecules at the interfaces of linear chain aggregation particles,at the inner side of non-linear chain aggregation particles,and at the centers of ring aggregation.These results are in good agreement with our previous experimental findings.More significantly,additional research has revealed that subcritical-size clusters typically aggregate on two-particle surfaces spacing when the spacing smaller than the critical cluster size.展开更多
The spreading effect of atmospheric pressure microplasma jets(APμPJ)on the surface of materials will increase the etching area,and controlling the diameter of the jet can improve the precision of surface treatment.In...The spreading effect of atmospheric pressure microplasma jets(APμPJ)on the surface of materials will increase the etching area,and controlling the diameter of the jet can improve the precision of surface treatment.In this work,a two-dimensional axisymmetric simulation model is established to analyze the effect of nitrogen(N_(2))shielding gas on helium(He)from gas dynamics.In addition,by etching the polyethylene terephthalate fllm,the relationship between the etching effect and aerodynamic analysis is verifled.The simulation results are similar to the experimental results,indicating that N2 shielding gas has a focusing effect which is related to the N_(2)flow rate,distance difference between the inner and outer tubes,and outer tube nozzle diameter.It is hoped that the results of this work can provide a certain reference for the use of shielding gas to control the jet flow of APμPJ.展开更多
Magnetoresistive sensor can be widely used in modem transportation field, such as the vehicle positioning and navigation system, vehicle detection system, and intelligent transportation system. In order to improve the...Magnetoresistive sensor can be widely used in modem transportation field, such as the vehicle positioning and navigation system, vehicle detection system, and intelligent transportation system. In order to improve the efficiency of magnetoresistive sensor, we synthesized Lao.sSro.2MnO3 polycrystalline bulks at different sintering temperatures and investigated their DC and AC transport properties in this work. As a result, all samples showed insulator-metal （I-M） phase transition, and the transition temperature （TI-M） shifted to higher temperature with the increase of sintering temperature. The TI-M measured at different AC frequencies was smaller than that measured at DC condition, which implied that the I-M phase transition was suppressed at AC frequencies. The resistivity mea- sured at high AC frequencies was larger than that measured at low AC frequencies, which could be attributed to the change of the magnetic penetration depth （6）. However, the room-temperature AC-magnetoresistance （MR） at low frequencies was much larger than that at high frequencies and room-temperature DC-MR. These findings demon- strate that reducing the AC frequency is an effective way for enhancing the room-temperature MR, which can be used to promote the efficiency of magnetoresistive sensor.展开更多
Increasing the 1,3,5-trioxane(TOX) concentration in the equilibrated vapor phase of TOX-H_(2)O system has been recognized as a challenge for the azeotrope. Ionic liquids(ILs) were used to improve the relative volatili...Increasing the 1,3,5-trioxane(TOX) concentration in the equilibrated vapor phase of TOX-H_(2)O system has been recognized as a challenge for the azeotrope. Ionic liquids(ILs) were used to improve the relative volatility of TOX to H_(2)O and destroy the azeotrope in the TOX-H2O system. The vapor-liquid equilibrium of TOX-H2O system at 101.3 kPa was studied with the addition of 1-butyl-3-methylimidazolium hydrogen sulfate, 1-hexyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimidazolium nitrate, respectively. The results showed that the volatility of TOX increased with the increase in IL dosage. And the volatility of water decreased with the increase in IL dosage. The relative volatility of TOX to H_(2)O was improved with the increase in ILs dosage. The azeotrope could be destroyed with an IL mole fraction of about 0.10. A non-random two-liquid(NRTL) model was successfully used to correlate the experimental data. The interaction parameters were obtained by fitting the experimental data with the model. The results indicated that a strong interaction existed between ILs and water. The strong interaction improved the volatility of TOX and inhibited the volatility of water, and then intensified the relative volatility of TOX to H_(2)O. The results showed that an ILs with strong polarity and hydrophilicity may be a potential additive to improve the TOX concentration in the equilibrated vapor phase.展开更多
基金The authors are supported by National Natural Sciences Foundation of China(11961060,11671322)the Key Project of Natural Sciences Foundation of Gansu Province(18JR3RA084).
文摘In this article,we consider a discrete right-definite Sturm-Liouville problems with two squared eigenparameter-dependent boundary conditions.By constructing some new Lagrange-type identities and two fundamental functions,we obtain not only the existence,the simplicity,and the interlacing properties of the real eigenvalues,but also the oscillation properties,orthogonality of the eigenfunctions,and the expansion theorem.Finally,we also give a computation scheme for computing eigenvalues and eigenfunctions of specific eigenvalue problems.
基金supported by the National Natural Science Foundation of China(Grant No.21576168)。
文摘The flow in a liquid falling film is predominantly laminar,and the liquid-side mass transfer is limited by molecular diffusion.The effective way to enhance the mass transfer is to improve the liquid film flow behavior.The falling film behaviors of water,ethanol and ethylene glycol in nine different wavy microchannels were simulated by Computational Fluid Dynamics.The simulation results show that the falling film thickness exhibits a waveform distribution resulting in a resonance phenomenon along the wavy microchannel.The fluctuation of liquid film surface increases the gas-liquid interface area,and the internal eddy flow inside the liquid film also improves the turbulence of liquid film,the gas-liquid mass transfer in falling film microchannels is intensified.Compared with flat microchannel,the CO_(2) absorption efficiency in water in the wavy microchannel is improved over 41%.Prediction models of liquid film amplitude and average liquid film thickness were established respectively.
基金supported by the Program of International S&T Cooperation 2013DFA51050National Magnetic Confinement Fusion Science Program (2011GB112001)+2 种基金Science Foundation of Sichuan Province (2011JY0031, 2011JY0130)the financial support of the National Natural Science Foundation of China (No. 51271155, No. 51002125)the Fundamental Research Funds for the Central Universities (SWJTU12CX018)
文摘Perovskite-based materials can be widely used in the aerospace and transportation field. Perovskite man-ganese oxides La0.7Sr0.3MnO3 （LSMO） thin films were grown on LaAlO3 （100） and Si （100） single crystal sub-strates by the polymer-assisted chemical solution deposi-tion （PACSD） method. Electronic transport behavior, microstructure, and magnetoresistance （MR） of LSMO thin films on different substrates were investigated. The resis-tance of LSMO films fabricated on LaAlO3 substrates is smaller than that on the Si substrates. The magnetic field reduces resistance of LSMO films both on Si and LAO in the wide temperature region, when the insulator-metal transition temperature shifts to higher temperature. The low-field magnetoresistance of LSMO films on Si in low temperature range at 1 T is larger than that of LSMO films on LAO. However, the MR of LSMO film on LAO films at room-temperature is about 5.17%. The thin films are smooth and dense with uniform nanocrystal size grain. These results demonstrate that PACSD is an effective technique for producing high quality LSMO films, which is significant to improve the magnetic properties and the application of automotive sensor.
基金supported by the National Natural Science Foundation of China(31772622)China Agriculture Research System(CARS-42-10)+2 种基金National Key R&D Program of China(2017YFD0502004)“111”project of Foreign Experts Affairs of ChinaSichuan Agricultural University 211 Foundation.
文摘Background:Consumption of resistant starch(RS)has been associated with various intestinal and systemic health benefits,but knowledge of its effects on intestinal health and inflammatory response in stressed birds is limited.Here,we examined how dietary RS supplementation from 12%raw potato starch(RPS)modulated inflammatory severity induced by lipopolysaccharide(LPS)in meat ducks.Results:LPS administration at 14,16,and 18 d(chronic challenge)decreased body weight(BW)and glucagon-like peptide 1 receptor(GLP-1R)level with higher intestinal permeability and inflammation,evident by higher proinflammatory cytokine levels.Dietary 12%RPS supplementation enhanced Claudin-1 and GLP-1R expression,along with lower levels of inflammatory factors in both ileum and serum.Microbiome analysis showed that RS treatment shifted microbial structure reflected by enriched the proportion of Firmicutes,Bifidobacterium,Ruminococcus,etc.Dietary RS addition also significantly increased the concentrations of propionate and butyrate during chronic LPS challenge.Furthermore,response to acute challenge,the ducks received 2 mg/kg BW LPS at 14 d had higher concentrations of serum endotoxins and inflammatory cytokines,as well as upregulated transcription of toll like receptor 4(TLR4)in ileum when compared to control birds.Analogous to GLP-1 agonist liraglutide,dietary RS addition decreased endotoxins and inflammation cytokines,whereas it upregulated the GLP-1 synthesis related genes expression.Meanwhile,dietary RS supplementation suppressed the acute LPS challenge-induced TLR4 transcription.Conclusions:These data suggest that dietary 12%RPS supplementation could attenuate the LPS-induced inflammation as well as intestinal injury of meat ducks,which might involve in the alteration in gut microbiota,SCFAs production and the signaling pathways of TLR4 and GLP-1/GLP-1R.
文摘Image reconstruction for list-mode time-of-flight(TOF)positron emission tomography(PET)can be achieved by analytic algorithms.The backprojection filtering(BPF)algorithm is an efficient algorithm for this task.The conventional noise control method for analytic image reconstruction is the use of a stationary lowpass filter,which does not model the Poisson noise properly.This study proposes a nonstationary filter for Poisson noise control.The filter is implemented in the spatial domain in a form similar to convolution.
文摘A specific, precise and accurate ion-pair HPLC-UV method has been developed and validated for simultaneous determination of phosphocreatine (PCr), and its metabolite creatine (Cr) as well as related ATP in plasma and red blood cell (RBC) of rabbits. After addition of TMP as IS, the samples were deproteinized with 6% PCA. The analytes were separated on a Kromasil C18 column using a tertiary gradient mobile phase composed of buffer A (0.2% KH2PO4 + 0.08% tetrabutyl ammonium hydrogen sulphate, pH 3.0), buffer B (buffer A adjusted to pH 7.5 with 1 mol/L NaOH) and MeOH. Detection wavelengths were set at 210 nm for PCr and Cr and 260 nm for ATP and TMP. Some blank samples were initially run for baseline subtraction. The linear detection responses were obtained for PCr concentration over a range of 10 - 7500 mg/ml (plasma) and 5 - 2500 mg/ml (RBC) and for both Cr and ATP concentrations of 10 - 1500 mg/ml (plasma) and 5 - 750 mg/ml (RBC) (r > 0.99). The QC samples of 3 analytes showed intra-day and inter-day precisions (RSD) of - 107%. The method was successfully used to simultaneously determine plasma and RBC concentrations of the 3 analytes and to study pharmacokinetics after iv administration of PCr to rabbits.
基金supported by National Natural Science Foundation of China(grant No.52176095)Anhui Provincial Natural Science Foundation(grant No.2308085ME189)China Postdoctoral Science Foundation(grant No.2019M661688).
文摘Water vapor nucleation on particle's surface plays an important role in dust removal,cloud formation,and particle measurement.However,the selectivity of nucleation sites and the nucleation characteristic of water molecule on the particle's surface are still unclear,especially for the aggregated particles.In this paper,the effects of particle wettability and aggregation modes on the selectivity of nucleation sites and the nucleation characteristics were investigated using molecular dynamics simulation.The results were compared with our earlier experimental findings.It illustrates how the contact angle of clusters,the growth velocity,and the growth duration are all influenced by the interaction coefficient between water and particles.Moreover,the nucleation sites of water molecules on the particle aggregation surface exhibit a definite selectivity.The primary indicator of this selectivity is the preferential nucleation of water molecules at the interfaces of linear chain aggregation particles,at the inner side of non-linear chain aggregation particles,and at the centers of ring aggregation.These results are in good agreement with our previous experimental findings.More significantly,additional research has revealed that subcritical-size clusters typically aggregate on two-particle surfaces spacing when the spacing smaller than the critical cluster size.
基金supported by National Natural Science Foundation of China(No.51905002)Anhui Provincial Natural Science Foundation(Nos.2008085QE230,2108085ME174)+2 种基金Open Project of Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials(No.GFST2021KF06)Open Project of Anhui Province Key Laboratory of Special and Heavy Load Robot(No.TZJQRO03-2021)Open Project of Anhui Province Engineering Laboratory of Intelligent Demolition Equipment(No.APELIDE2021B001)。
文摘The spreading effect of atmospheric pressure microplasma jets(APμPJ)on the surface of materials will increase the etching area,and controlling the diameter of the jet can improve the precision of surface treatment.In this work,a two-dimensional axisymmetric simulation model is established to analyze the effect of nitrogen(N_(2))shielding gas on helium(He)from gas dynamics.In addition,by etching the polyethylene terephthalate fllm,the relationship between the etching effect and aerodynamic analysis is verifled.The simulation results are similar to the experimental results,indicating that N2 shielding gas has a focusing effect which is related to the N_(2)flow rate,distance difference between the inner and outer tubes,and outer tube nozzle diameter.It is hoped that the results of this work can provide a certain reference for the use of shielding gas to control the jet flow of APμPJ.
基金supported by the National Magnetic Confinement Fusion Science Program (No. 2011GB112001)Program of International S&T Cooperation (No. 2013DFA51050)+3 种基金the National Natural Science Foundation of China (Nos. 51002125, 11104224, 11004162, and 51271155)the Research Fund for the Doctoral Program of Higher Education of China (No. 20110184120029)the Fundamental Research Funds for the Central Universities (Nos. 2682013ZT16, SWJTU12CX18, SWJTU11ZT31, 2682013CX004, and SWJTU11BR063)the Science Foundation of Sichuan Province (Nos. 2011JY0031 and 2011JY0130)
文摘Magnetoresistive sensor can be widely used in modem transportation field, such as the vehicle positioning and navigation system, vehicle detection system, and intelligent transportation system. In order to improve the efficiency of magnetoresistive sensor, we synthesized Lao.sSro.2MnO3 polycrystalline bulks at different sintering temperatures and investigated their DC and AC transport properties in this work. As a result, all samples showed insulator-metal （I-M） phase transition, and the transition temperature （TI-M） shifted to higher temperature with the increase of sintering temperature. The TI-M measured at different AC frequencies was smaller than that measured at DC condition, which implied that the I-M phase transition was suppressed at AC frequencies. The resistivity mea- sured at high AC frequencies was larger than that measured at low AC frequencies, which could be attributed to the change of the magnetic penetration depth （6）. However, the room-temperature AC-magnetoresistance （MR） at low frequencies was much larger than that at high frequencies and room-temperature DC-MR. These findings demon- strate that reducing the AC frequency is an effective way for enhancing the room-temperature MR, which can be used to promote the efficiency of magnetoresistive sensor.
基金supported by the fundamental research funds for the central universities(2022SCUH0041,SCU2023D012).
文摘Increasing the 1,3,5-trioxane(TOX) concentration in the equilibrated vapor phase of TOX-H_(2)O system has been recognized as a challenge for the azeotrope. Ionic liquids(ILs) were used to improve the relative volatility of TOX to H_(2)O and destroy the azeotrope in the TOX-H2O system. The vapor-liquid equilibrium of TOX-H2O system at 101.3 kPa was studied with the addition of 1-butyl-3-methylimidazolium hydrogen sulfate, 1-hexyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimidazolium nitrate, respectively. The results showed that the volatility of TOX increased with the increase in IL dosage. And the volatility of water decreased with the increase in IL dosage. The relative volatility of TOX to H_(2)O was improved with the increase in ILs dosage. The azeotrope could be destroyed with an IL mole fraction of about 0.10. A non-random two-liquid(NRTL) model was successfully used to correlate the experimental data. The interaction parameters were obtained by fitting the experimental data with the model. The results indicated that a strong interaction existed between ILs and water. The strong interaction improved the volatility of TOX and inhibited the volatility of water, and then intensified the relative volatility of TOX to H_(2)O. The results showed that an ILs with strong polarity and hydrophilicity may be a potential additive to improve the TOX concentration in the equilibrated vapor phase.
