Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consi...Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consider linear correlations between features(indicators)of the source and target projects.These models are not capable of evaluating non-linear correlations between features when they exist,for example,when there are differences in data distributions between the source and target projects.As a result,the performance of such CPDP models is compromised.In this paper,this paper proposes a novel CPDP method based on Synthetic Minority Oversampling Technique(SMOTE)and Deep Canonical Correlation Analysis(DCCA),referred to as S-DCCA.Canonical Correlation Analysis(CCA)is employed to address the issue of non-linear correlations between features of the source and target projects.S-DCCA extends CCA by incorporating the MlpNet model for feature extraction from the dataset.The redundant features are then eliminated by maximizing the correlated feature subset using the CCA loss function.Finally,cross-project defect prediction is achieved through the application of the SMOTE data sampling technique.Area Under Curve(AUC)and F1 scores(F1)are used as evaluation metrics.This paper conducted experiments on 27 projects from four public datasets to validate the proposed method.The results demonstrate that,on average,our method outperforms all baseline approaches by at least 1.2%in AUC and 5.5%in F1 score.This indicates that the proposed method exhibits favorable performance characteristics.展开更多
Decision implication is a form of decision knowledge represen-tation,which is able to avoid generating attribute implications that occur between condition attributes and between decision attributes.Compared with other...Decision implication is a form of decision knowledge represen-tation,which is able to avoid generating attribute implications that occur between condition attributes and between decision attributes.Compared with other forms of decision knowledge representation,decision implication has a stronger knowledge representation capability.Attribute granularization may facilitate the knowledge extraction of different attribute granularity layers and thus is of application significance.Decision implication canonical basis(DICB)is the most compact set of decision implications,which can efficiently represent all knowledge in the decision context.In order to mine all deci-sion information on decision context under attribute granulating,this paper proposes an updated method of DICB.To this end,the paper reduces the update of DICB to the updates of decision premises after deleting an attribute and after adding granulation attributes of some attributes.Based on this,the paper analyzes the changes of decision premises,examines the properties of decision premises,designs an algorithm for incrementally generating DICB,and verifies its effectiveness through experiments.In real life,by using the updated algorithm of DICB,users may obtain all decision knowledge on decision context after attribute granularization.展开更多
Biometric gait recognition is a lesser-known but emerging and effective biometric recognition method which enables subjects’walking patterns to be recognized.Existing research in this area has primarily focused on fe...Biometric gait recognition is a lesser-known but emerging and effective biometric recognition method which enables subjects’walking patterns to be recognized.Existing research in this area has primarily focused on feature analysis through the extraction of individual features,which captures most of the information but fails to capture subtle variations in gait dynamics.Therefore,a novel feature taxonomy and an approach for deriving a relationship between a function of one set of gait features with another set are introduced.The gait features extracted from body halves divided by anatomical planes on vertical,horizontal,and diagonal axes are grouped to form canonical gait covariates.Canonical Correlation Analysis is utilized to measure the strength of association between the canonical covariates of gait.Thus,gait assessment and identification are enhancedwhenmore semantic information is available through CCA-basedmulti-feature fusion.Hence,CarnegieMellon University’s 3D gait database,which contains 32 gait samples taken at different paces,is utilized in analyzing gait characteristics.The performance of Linear Discriminant Analysis,K-Nearest Neighbors,Naive Bayes,Artificial Neural Networks,and Support Vector Machines was improved by a 4%average when the CCA-utilized gait identification approachwas used.Asignificant maximumaccuracy rate of 97.8%was achieved throughCCA-based gait identification.Beyond that,the rate of false identifications and unrecognized gaits went down to half,demonstrating state-of-the-art for gait identification.展开更多
Grand canonical Monte Carlo simulation(GCMCs)is utilized for studying hydrogen storage gravimetric density by pha-graphene at different metal densities,temperatures and pressures.It is demonstrated that the optimum ad...Grand canonical Monte Carlo simulation(GCMCs)is utilized for studying hydrogen storage gravimetric density by pha-graphene at different metal densities,temperatures and pressures.It is demonstrated that the optimum adsorbent location for Li atoms is the center of the seven-membered ring of pha-graphene.The binding energy of Li-decorated phagraphene is larger than the cohesive energy of Li atoms,implying that Li can be distributed on the surface of pha-graphene without forming metal clusters.We fitted the force field parameters of Li and C atoms at different positions and performed GCMCs to study the absorption capacity of H_(2).The capacity of hydrogen storage was studied by the differing density of Li decoration.The maximum hydrogen storage capacity of 4Li-decorated pha-graphene was 15.88 wt%at 77 K and100 bar.The enthalpy values of adsorption at the three densities are in the ideal range of 15 kJ·mol^(-1)-25 kJ·mol^(-1).The GCMC results at different pressures and temperatures show that with the increase in Li decorative density,the hydrogen storage gravimetric ratio of pha-graphene decreases but can reach the 2025 US Department of Energy's standard(5.5 wt%).Therefore,pha-graphene is considered to be a potential hydrogen storage material.展开更多
Triple Negative Breast Cancer (TNBC) is a malignant form of cancer with very high mortality and morbidity. Epithelial to Mesenchymal Transition (EMT) is the most common pathophysiological change observed in cancer cel...Triple Negative Breast Cancer (TNBC) is a malignant form of cancer with very high mortality and morbidity. Epithelial to Mesenchymal Transition (EMT) is the most common pathophysiological change observed in cancer cells of epithelial origin that promotes metastasis, drug resistance and cancer stem cell formation. Since the information regarding differential gene expression in TNBC cells and cell signaling events leading to EMT is limited, this investigation was done by comparing transcriptomic data generated by RNA isolation and sequencing of a EMT model TNBC cell line in comparison to regular TNBC cells. RNA sequencing and Ingenuity Pathway Software Analysis (IPA) of the transcriptomic data revealed several upregulated and downregulated gene expressions along with novel core canonical pathways including Sirtuin signaling, Oxidative Phosphorylation and Mitochondrial dysfunction events involved in EMT changes of the TNBC cells.展开更多
Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showe...Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P<0.05 and P<0.01, respectively). The first toxicity canonical variable (TOXI), formed from the toxicity data set, explained 49% of the total variance in the toxicity data set; the first biological canonical variable(BIOL) explained 42% of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (P<0.0001). Therefore, it is reliable and feasible to use the achievement to assess toxicity of heavy metal combined polluted soil using canonical analysis. Toxicity of soil combined polluted by heavy metals to plant community was estimated by comparing the IC 50 values describing the concentration needed to cause 50% decrease with grow rate compared to no metal addition. Environmental quality standard for soils prescribe that all these tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features.展开更多
The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system are studied. The relations between the invariants and the symmetries of the ...The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system are studied. The relations between the invariants and the symmetries of the system are established. Based on the concept of higher-order adiabatic invariant of a mechanical system under the action of a small perturbation, the forms of the exact invariants and adiabatic invariants and the conditions for their existence are proved. Finally, the inverse problem of the perturbation to symmetries of the system is studied and an example is also given to illustrate the application of the results.展开更多
The adsorption behavior of benzene and propylene in zeolite ZSM-5 was studied by Grand Canonical Monte Carlo(GCMC) simulations. It could be found that benzene and propylene molecules showed different adsorption beha...The adsorption behavior of benzene and propylene in zeolite ZSM-5 was studied by Grand Canonical Monte Carlo(GCMC) simulations. It could be found that benzene and propylene molecules showed different adsorption behavior in the zeolite cavities. The loadings of propylene were significantly larger than those of benzene at 100 kPa. From the figures of potential energy distribution, the potential energy of benzene/zeolite was more negative than that of propylene/zeolite, so benzene could be adsorbed more stably than propylene. When the temperature was in- creased from 298 to 443 K at 100 kPa, the loading ofpropylene was reduced from 99 to 82 molecules, whereas that of benzene changed little. When benzene and propylene were adsorbed in zeolite simultaneously, the competitive adsorption of them occurred; therefore, the potential energy distribution could be changed significantly. Besides, the adsorption isotherms of benzene and propylene in ZSM-5 at 298 and 443 K were simulated. The results exhibit that the different factors influenced the molecular adsorption at various temperatures and pressures, leading to the diffe- rent rules for the adsorption of benzene and propylene molecules in the zeolite. At a low pressure, the unfavorable energy of propylene/zeolite and the "commensurate freezing" phenomenon of benzene would make the loadings of itself higher than those of propylene. When pressure was higher than 5 kPa, the adsorption of benzene in ZSM-5 would nearly reach saturation.展开更多
The concepts of branching chain in random environmnet and canonical branching chain in random environment are introduced. Moreover the existence of these chains is proved. Finally the exact formulas of mathematical ex...The concepts of branching chain in random environmnet and canonical branching chain in random environment are introduced. Moreover the existence of these chains is proved. Finally the exact formulas of mathematical expectation and variance of branching chain in random environment are also given.展开更多
The diffusion and adsorption behaviors of benzene and propylene in zeolites MFI, MWW and BEA have been studied by molecular dynamics(MD) and grand canonical Monte Carlo(GCMC) simulations. The diffusion coefficient...The diffusion and adsorption behaviors of benzene and propylene in zeolites MFI, MWW and BEA have been studied by molecular dynamics(MD) and grand canonical Monte Carlo(GCMC) simulations. The diffusion coefficients of benzene and propylene in MFI, MWW and BEA zeolites were calculated by simulating the mean-square displacements(MSD) at 298 and 600 K. Benzene and propylene showed the different adsorption rules in the channels of the three zeolites. For propylene, the molecular loadings decreased in the order: BEA(linear channel)〉BEA (tortuous channel)〉MFI(linear channel)〉MWW(12-membered rings, 12MR channel)〉MFI(tortuous channel)〉MWW (10-membered rings, 10MR channel); for benzene, the molecular loadings decreased in the order: BEA(linear chan-nel)〉BEA(tortuous channel)〉MWW(12MR channel)〉MFI(linear channel)〉MFI(tortuous channel)〉MWW(10MR channel). Besides, the adsorption isotherms of benzene and propylene in the three zeolites at 298 and 443 K were simulated. The results show that the different factors influenced the molecular adsorption at various temperatures and pressures, leading to the different rules for the adsorption of benzene and propylene molecules in the zeolites. At a low pressure, the unfavorable energy would make the loadings of propylene lower than those of benzene. When pressure was higher than 0.25 kPa, the adsorption of benzene in MFI would nearly reach saturation.展开更多
The theory of time scales,which unifies continuous and discrete analysis,provides a powerful mathematical tool for the study of complex dynamic systems.It enables us to understand more clearly the essential problems o...The theory of time scales,which unifies continuous and discrete analysis,provides a powerful mathematical tool for the study of complex dynamic systems.It enables us to understand more clearly the essential problems of continuous systems and discrete systems as well as other complex systems.In this paper,the theory of generalized canonical transformation for second-order Birkhoffian systems on time scales is proposed and studied,which extends the canonical transformation theory of Hamilton canonical equations.First,the condition of generalized canonical transformation for the second-order Birkhoffian system on time scales is established.Second,based on this condition,six basic forms of generalized canonical transformation for the second-order Birkhoffian system on time scales are given.Also,the relationships between new variables and old variables for each of these cases are derived.In the end,an example is given to show the application of the results.展开更多
Using factorization viewpoint of differential operator, this paper discusses how to transform a nonlinear evolution equation to infinite-dimensional Hamiltonian linear canonical formulation. It proves a sufficient con...Using factorization viewpoint of differential operator, this paper discusses how to transform a nonlinear evolution equation to infinite-dimensional Hamiltonian linear canonical formulation. It proves a sufficient condition of canonical factorization of operator, and provides a kind of mechanical algebraic method to achieve canonical 'σ/σx'-type expression, correspondingly. Then three examples are given, which show the application of the obtained algorithm. Thus a novel idea for inverse problem can be derived feasibly.展开更多
Both bone morphogenetic protein 2(BMP2) and the wingless-type MMTV integration site(WNT)/p-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis.Cross-talk between BMP2 ...Both bone morphogenetic protein 2(BMP2) and the wingless-type MMTV integration site(WNT)/p-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis.Cross-talk between BMP2 and WNT/p-catenin in osteoblast differentiation and bone formation has been identified.However,the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown.Here,we demonstrate that BMP2 promotes the differentiation of human dental pulp cells(HDPCs) by activating WNT/p-catenin signalling,which is further mediated by p38mitogen-activated protein kinase(MAPK) in vitro.BMP2 stimulation upregulated the expression of p-catenin in HDPCs,which was abolished by SB203580 but not by Noggin or LDN193189.Furthermore,BMP2 enhanced cell differentiation,which was not fully inhibited by Noggin or LDN193189.Instead,SB203580 partially blocked BMP2-induced p-catenin expression and cell differentiation.Taken together,these data suggest a possible mechanism by which the elevation of p-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway,which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation.展开更多
基金NationalNatural Science Foundation of China,Grant/AwardNumber:61867004National Natural Science Foundation of China Youth Fund,Grant/Award Number:41801288.
文摘Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consider linear correlations between features(indicators)of the source and target projects.These models are not capable of evaluating non-linear correlations between features when they exist,for example,when there are differences in data distributions between the source and target projects.As a result,the performance of such CPDP models is compromised.In this paper,this paper proposes a novel CPDP method based on Synthetic Minority Oversampling Technique(SMOTE)and Deep Canonical Correlation Analysis(DCCA),referred to as S-DCCA.Canonical Correlation Analysis(CCA)is employed to address the issue of non-linear correlations between features of the source and target projects.S-DCCA extends CCA by incorporating the MlpNet model for feature extraction from the dataset.The redundant features are then eliminated by maximizing the correlated feature subset using the CCA loss function.Finally,cross-project defect prediction is achieved through the application of the SMOTE data sampling technique.Area Under Curve(AUC)and F1 scores(F1)are used as evaluation metrics.This paper conducted experiments on 27 projects from four public datasets to validate the proposed method.The results demonstrate that,on average,our method outperforms all baseline approaches by at least 1.2%in AUC and 5.5%in F1 score.This indicates that the proposed method exhibits favorable performance characteristics.
基金supported by the National Natural Science Foundation of China (Nos.61972238,62072294).
文摘Decision implication is a form of decision knowledge represen-tation,which is able to avoid generating attribute implications that occur between condition attributes and between decision attributes.Compared with other forms of decision knowledge representation,decision implication has a stronger knowledge representation capability.Attribute granularization may facilitate the knowledge extraction of different attribute granularity layers and thus is of application significance.Decision implication canonical basis(DICB)is the most compact set of decision implications,which can efficiently represent all knowledge in the decision context.In order to mine all deci-sion information on decision context under attribute granulating,this paper proposes an updated method of DICB.To this end,the paper reduces the update of DICB to the updates of decision premises after deleting an attribute and after adding granulation attributes of some attributes.Based on this,the paper analyzes the changes of decision premises,examines the properties of decision premises,designs an algorithm for incrementally generating DICB,and verifies its effectiveness through experiments.In real life,by using the updated algorithm of DICB,users may obtain all decision knowledge on decision context after attribute granularization.
基金supported by Istanbul University Scientific Research Project Department with IRP-51706 Project Number.
文摘Biometric gait recognition is a lesser-known but emerging and effective biometric recognition method which enables subjects’walking patterns to be recognized.Existing research in this area has primarily focused on feature analysis through the extraction of individual features,which captures most of the information but fails to capture subtle variations in gait dynamics.Therefore,a novel feature taxonomy and an approach for deriving a relationship between a function of one set of gait features with another set are introduced.The gait features extracted from body halves divided by anatomical planes on vertical,horizontal,and diagonal axes are grouped to form canonical gait covariates.Canonical Correlation Analysis is utilized to measure the strength of association between the canonical covariates of gait.Thus,gait assessment and identification are enhancedwhenmore semantic information is available through CCA-basedmulti-feature fusion.Hence,CarnegieMellon University’s 3D gait database,which contains 32 gait samples taken at different paces,is utilized in analyzing gait characteristics.The performance of Linear Discriminant Analysis,K-Nearest Neighbors,Naive Bayes,Artificial Neural Networks,and Support Vector Machines was improved by a 4%average when the CCA-utilized gait identification approachwas used.Asignificant maximumaccuracy rate of 97.8%was achieved throughCCA-based gait identification.Beyond that,the rate of false identifications and unrecognized gaits went down to half,demonstrating state-of-the-art for gait identification.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11904175,11804169,and 11804165)the Graduate Innovation Project of Jiangsu Province,China(Grant No.KYCX210700)。
文摘Grand canonical Monte Carlo simulation(GCMCs)is utilized for studying hydrogen storage gravimetric density by pha-graphene at different metal densities,temperatures and pressures.It is demonstrated that the optimum adsorbent location for Li atoms is the center of the seven-membered ring of pha-graphene.The binding energy of Li-decorated phagraphene is larger than the cohesive energy of Li atoms,implying that Li can be distributed on the surface of pha-graphene without forming metal clusters.We fitted the force field parameters of Li and C atoms at different positions and performed GCMCs to study the absorption capacity of H_(2).The capacity of hydrogen storage was studied by the differing density of Li decoration.The maximum hydrogen storage capacity of 4Li-decorated pha-graphene was 15.88 wt%at 77 K and100 bar.The enthalpy values of adsorption at the three densities are in the ideal range of 15 kJ·mol^(-1)-25 kJ·mol^(-1).The GCMC results at different pressures and temperatures show that with the increase in Li decorative density,the hydrogen storage gravimetric ratio of pha-graphene decreases but can reach the 2025 US Department of Energy's standard(5.5 wt%).Therefore,pha-graphene is considered to be a potential hydrogen storage material.
文摘Triple Negative Breast Cancer (TNBC) is a malignant form of cancer with very high mortality and morbidity. Epithelial to Mesenchymal Transition (EMT) is the most common pathophysiological change observed in cancer cells of epithelial origin that promotes metastasis, drug resistance and cancer stem cell formation. Since the information regarding differential gene expression in TNBC cells and cell signaling events leading to EMT is limited, this investigation was done by comparing transcriptomic data generated by RNA isolation and sequencing of a EMT model TNBC cell line in comparison to regular TNBC cells. RNA sequencing and Ingenuity Pathway Software Analysis (IPA) of the transcriptomic data revealed several upregulated and downregulated gene expressions along with novel core canonical pathways including Sirtuin signaling, Oxidative Phosphorylation and Mitochondrial dysfunction events involved in EMT changes of the TNBC cells.
文摘Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P<0.05 and P<0.01, respectively). The first toxicity canonical variable (TOXI), formed from the toxicity data set, explained 49% of the total variance in the toxicity data set; the first biological canonical variable(BIOL) explained 42% of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (P<0.0001). Therefore, it is reliable and feasible to use the achievement to assess toxicity of heavy metal combined polluted soil using canonical analysis. Toxicity of soil combined polluted by heavy metals to plant community was estimated by comparing the IC 50 values describing the concentration needed to cause 50% decrease with grow rate compared to no metal addition. Environmental quality standard for soils prescribe that all these tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features.
基金Project supported by the Heilongjiang Natural Science Foundation of China (Grant No 9507).
文摘The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system are studied. The relations between the invariants and the symmetries of the system are established. Based on the concept of higher-order adiabatic invariant of a mechanical system under the action of a small perturbation, the forms of the exact invariants and adiabatic invariants and the conditions for their existence are proved. Finally, the inverse problem of the perturbation to symmetries of the system is studied and an example is also given to illustrate the application of the results.
基金Supported by the National Natural Science Foundation of China(Nos.20576012 and 20625621)
文摘The adsorption behavior of benzene and propylene in zeolite ZSM-5 was studied by Grand Canonical Monte Carlo(GCMC) simulations. It could be found that benzene and propylene molecules showed different adsorption behavior in the zeolite cavities. The loadings of propylene were significantly larger than those of benzene at 100 kPa. From the figures of potential energy distribution, the potential energy of benzene/zeolite was more negative than that of propylene/zeolite, so benzene could be adsorbed more stably than propylene. When the temperature was in- creased from 298 to 443 K at 100 kPa, the loading ofpropylene was reduced from 99 to 82 molecules, whereas that of benzene changed little. When benzene and propylene were adsorbed in zeolite simultaneously, the competitive adsorption of them occurred; therefore, the potential energy distribution could be changed significantly. Besides, the adsorption isotherms of benzene and propylene in ZSM-5 at 298 and 443 K were simulated. The results exhibit that the different factors influenced the molecular adsorption at various temperatures and pressures, leading to the diffe- rent rules for the adsorption of benzene and propylene molecules in the zeolite. At a low pressure, the unfavorable energy of propylene/zeolite and the "commensurate freezing" phenomenon of benzene would make the loadings of itself higher than those of propylene. When pressure was higher than 5 kPa, the adsorption of benzene in ZSM-5 would nearly reach saturation.
文摘The concepts of branching chain in random environmnet and canonical branching chain in random environment are introduced. Moreover the existence of these chains is proved. Finally the exact formulas of mathematical expectation and variance of branching chain in random environment are also given.
基金Supported by the National Natural Science Foundation of China(No.20576012)the Doctoral Fund of Qingdao University of Science and Technology China(No. 0022430)
文摘The diffusion and adsorption behaviors of benzene and propylene in zeolites MFI, MWW and BEA have been studied by molecular dynamics(MD) and grand canonical Monte Carlo(GCMC) simulations. The diffusion coefficients of benzene and propylene in MFI, MWW and BEA zeolites were calculated by simulating the mean-square displacements(MSD) at 298 and 600 K. Benzene and propylene showed the different adsorption rules in the channels of the three zeolites. For propylene, the molecular loadings decreased in the order: BEA(linear channel)〉BEA (tortuous channel)〉MFI(linear channel)〉MWW(12-membered rings, 12MR channel)〉MFI(tortuous channel)〉MWW (10-membered rings, 10MR channel); for benzene, the molecular loadings decreased in the order: BEA(linear chan-nel)〉BEA(tortuous channel)〉MWW(12MR channel)〉MFI(linear channel)〉MFI(tortuous channel)〉MWW(10MR channel). Besides, the adsorption isotherms of benzene and propylene in the three zeolites at 298 and 443 K were simulated. The results show that the different factors influenced the molecular adsorption at various temperatures and pressures, leading to the different rules for the adsorption of benzene and propylene molecules in the zeolites. At a low pressure, the unfavorable energy would make the loadings of propylene lower than those of benzene. When pressure was higher than 0.25 kPa, the adsorption of benzene in MFI would nearly reach saturation.
基金supported by the National Natural Science Foundation of China(Grants 11972241 and 11572212)
文摘The theory of time scales,which unifies continuous and discrete analysis,provides a powerful mathematical tool for the study of complex dynamic systems.It enables us to understand more clearly the essential problems of continuous systems and discrete systems as well as other complex systems.In this paper,the theory of generalized canonical transformation for second-order Birkhoffian systems on time scales is proposed and studied,which extends the canonical transformation theory of Hamilton canonical equations.First,the condition of generalized canonical transformation for the second-order Birkhoffian system on time scales is established.Second,based on this condition,six basic forms of generalized canonical transformation for the second-order Birkhoffian system on time scales are given.Also,the relationships between new variables and old variables for each of these cases are derived.In the end,an example is given to show the application of the results.
基金Project supported by the National Natural Science Foundation of China (Grant No 10562002) and the Natural Science Foundation of Nei Mongol, China (Grant No 200508010103).
文摘Using factorization viewpoint of differential operator, this paper discusses how to transform a nonlinear evolution equation to infinite-dimensional Hamiltonian linear canonical formulation. It proves a sufficient condition of canonical factorization of operator, and provides a kind of mechanical algebraic method to achieve canonical 'σ/σx'-type expression, correspondingly. Then three examples are given, which show the application of the obtained algorithm. Thus a novel idea for inverse problem can be derived feasibly.
基金supported by the National Nature Science Foundation of China(grant nos.81200759,81070801 and 813220170)the Innovative Research Team of the Education Department of Sichuan Province(13TD0038)+1 种基金the Sichuan Province Science and Technology Support Program(2012SZ0034)the Program of International Science and Technology Cooperation(2014DFA31990)
文摘Both bone morphogenetic protein 2(BMP2) and the wingless-type MMTV integration site(WNT)/p-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis.Cross-talk between BMP2 and WNT/p-catenin in osteoblast differentiation and bone formation has been identified.However,the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown.Here,we demonstrate that BMP2 promotes the differentiation of human dental pulp cells(HDPCs) by activating WNT/p-catenin signalling,which is further mediated by p38mitogen-activated protein kinase(MAPK) in vitro.BMP2 stimulation upregulated the expression of p-catenin in HDPCs,which was abolished by SB203580 but not by Noggin or LDN193189.Furthermore,BMP2 enhanced cell differentiation,which was not fully inhibited by Noggin or LDN193189.Instead,SB203580 partially blocked BMP2-induced p-catenin expression and cell differentiation.Taken together,these data suggest a possible mechanism by which the elevation of p-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway,which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation.