Developing bimetallic catalysts is an effective strategy for enhancing the activity and selectivity of electrochemical CO_(2) reduction reactions,where understanding the structure-activity relationship is essential fo...Developing bimetallic catalysts is an effective strategy for enhancing the activity and selectivity of electrochemical CO_(2) reduction reactions,where understanding the structure-activity relationship is essential for catalyst design.Herein,we prepared two Cu-Ag bimetallic catalysts with Ag nanoparticles attached to the top or the bottom of Cu nanowires.When tested in a flow cell,the Cu-Ag catalyst with Ag nanoparticles on the bottom achieved a faradaic efficiency of 54%for ethylene production,much higher than the catalyst with Ag nanoparticles on the top.The catalysts were further studied in the H-cell and zero-gap MEA cell.It was found that placing the two metals in the intensified reaction zone is crucial to triggering the tandem reaction of bimetallic catalysts.Our work elucidates the structure-activity relationship of bimetallic catalysts for CO_(2) reduction and demonstrates the importance of considering both catalyst structures and cell characteristics to achieve high activity and selectivity.展开更多
The isothermal compression tests were carried out in the Thermecmastor-Z thermo-simulator at temperatures of 800, 850, 900, 950, 1000 and 1050 ℃ and the strain rates of 0.01, 0.1, 1 and 10 s-1. The influence of defor...The isothermal compression tests were carried out in the Thermecmastor-Z thermo-simulator at temperatures of 800, 850, 900, 950, 1000 and 1050 ℃ and the strain rates of 0.01, 0.1, 1 and 10 s-1. The influence of deformation temperature and strain rate on the flow stress of Ti-6Al-2Zr-IMo-IV alloy was studied. Based on the experimental data sets, the high temperature deformation behavior of Ti-6A1-2Zr-IMo-IV alloy was presented using the intelligent method of artificial neural network （ANN）. The results indicate that the predicted flow stress values by ANN model is quite consistent with the experimental results, which implies that the artificial neural network is an effective tool for studying the hot deformation behavior of the present alloy. In addition, the development of graphical user interface is implemented using Visual Basic programming language.展开更多
对32个碳环类神经氨酸酶抑制剂进行了二维定量构效关系(2D-QSAR)研究,27个作为训练集,5个作为测试集,对计算所得的理化和量化参数进行预选后,采用偏最小二乘法(Partial least squares,PLS)建立预测模型,该模型的非交叉法验证相关系数为R...对32个碳环类神经氨酸酶抑制剂进行了二维定量构效关系(2D-QSAR)研究,27个作为训练集,5个作为测试集,对计算所得的理化和量化参数进行预选后,采用偏最小二乘法(Partial least squares,PLS)建立预测模型,该模型的非交叉法验证相关系数为R2=0.976 2,交叉法验证相关系数为R2CV=0.965 1;以此预测模型对测试集的5个化合物的活性进行预测,相关系数为R2pred=0.877 9,表明该模型具有较强的预测能力,可以指导对已有的流感药物进行化学修饰,并能指导新的神经氨酸酶抑制剂的设计及合成.展开更多
In this paper, CoMFA method was applied to study the 3D QSAR on a series of 3 anilinomethylene 6 alkyl (aryl) 5,6 2H dihydropyran 2, 4 dione compounds, which were designed and synthesized referring to the natural toxi...In this paper, CoMFA method was applied to study the 3D QSAR on a series of 3 anilinomethylene 6 alkyl (aryl) 5,6 2H dihydropyran 2, 4 dione compounds, which were designed and synthesized referring to the natural toxic Alternaric acid structure. The results displayed the information on modification of primary molecules and further synthesis of new bioactive compounds.展开更多
Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carbo...Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carboxylic acids to study the relationship betweentheir structure and the affinity for the glycine site of the NMDA receptor. Result Hie coefficientsof cross-validation q^2 and non cross-validation r^2 for the model established by the study are0.744 and 0.993, respectively, the value of variance ratio F is 261.343, and standard error estimate(SE) is 0.039. Conclusion These values indicate that the CoMFA model may have a good prediction forthe activity of C-3 substituted 4, 6-dichloroin-dole-2-carboxylic acids. As a consequence, thepredicted activity values of new designed compounds supports our conclusion from the model.展开更多
By investigating the types of 371 non-English major freshmen's use of mother-tongue-reliance strategies in English languagelearning,the study showed that students' use of mother-tongue-reliance strategies woul...By investigating the types of 371 non-English major freshmen's use of mother-tongue-reliance strategies in English languagelearning,the study showed that students' use of mother-tongue-reliance strategies would vary significantly with their different L2 profi-ciency.And it was negatively correlated with L2 proficiency.And the study discussed the implications to guide English language teach-ing and learning.展开更多
The Two-dimensional Quantitative Structure-activity Relationship （2D-QSAR） of a series of novel norcantharidin analogues, which exhibit hnhibitory activities of protein phosphatase 1 and 2A （PP1 and PP2A）, has bee...The Two-dimensional Quantitative Structure-activity Relationship （2D-QSAR） of a series of novel norcantharidin analogues, which exhibit hnhibitory activities of protein phosphatase 1 and 2A （PP1 and PP2A）, has been studied with a combined method of ab initio （I/F）, molecular mechanics （MM＋） and statistics. The established 2D-QSAR model （Eq. 1） for PP1 shows a reasonable regressive performance （R2= 0.749）, and the hydrophobic property of this molecule plays a decisive role in determining the inhibitory activity of PP1. In addition, the established 2D-QSAR model （Eq. 2） for PP2A also shows an acceptable regressive performance （R2= 0.701）, and the dipole moment of the molecule determines the inhibitory activity of PP2A.展开更多
Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic...Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.展开更多
A series of novel derivatives of 4, 5, 6, 7-tetrahydrothieno [3,2-c] pyridine were synthesized and structurally characterized by 1H NMR and MS. Their in vivo anti-platelet aggregation activities were evaluated. A 3D-Q...A series of novel derivatives of 4, 5, 6, 7-tetrahydrothieno [3,2-c] pyridine were synthesized and structurally characterized by 1H NMR and MS. Their in vivo anti-platelet aggregation activities were evaluated. A 3D-QSAR was performed using the CoMFA and the CoMSIA. This model provided useful guidelines for novel anti-platelet thienopyridines design.展开更多
Enhancer of Zeste homolog 2（EZH2） is closely correlated with malignant tumor and regarded as a promising target to treat B-cell lymphoma. In our research, the molecular docking and three-dimensional quantitative str...Enhancer of Zeste homolog 2（EZH2） is closely correlated with malignant tumor and regarded as a promising target to treat B-cell lymphoma. In our research, the molecular docking and three-dimensional quantitative structure-activity relationships（3D-QSAR） studies were performed on a series of pyridone-based EZH2 compounds. Molecular docking allowed us to study the critical interactions at the binding site of EZH2 protein with inhibitors and identify the practical conformations of ligands in binding pocket. Moreover, the docking-based alignment was applied to derive the reliable 3D-QSAR models. Comparative molecular field analysis（CoMFA） and comparative molecular similarity indices analysis（CoMSIA） provided available ability of visualization. All the derived 3D-QSAR models were considered to be statistically significant with respect to the internal and external validation parameters. For the CoMFA model, q^2 = 0.649, r^2 = 0.961 and r^2 pred = 0.877. For the CoMSIA model, q^2 = 0.733, r^2 = 0.980 and r^2 pred = 0.848. With the above arguments, we extracted the correlation between the biological activity and structure. Based on the binding interaction and 3D contour maps, several new potential inhibitors with higher biological activity predicted were designed, which still awaited experimental validation. These theoretical conclusions could be helpful for further research and exploring potential EZH2 inhibitors.展开更多
A Mn18Cr2 steel containing TiN precipitates was fabricated by vacuum induction melting.The morphology of TiN precipitates and the interface orientation relationship between TiN and γ-Fe were characterized by means of...A Mn18Cr2 steel containing TiN precipitates was fabricated by vacuum induction melting.The morphology of TiN precipitates and the interface orientation relationship between TiN and γ-Fe were characterized by means of SEM,TEM and SAED,and the formation mechanism of TiN precipitates in Mn18Cr2 steel was clarified.Results show that the TiN precipitates are more likely to exhibit a cubic-shaped morphology and form both within the grain and at the grain boundary of γ-Fe.The interface orientation relationship between TiN and γ-Fe is determined as follows:(100)_(TiN)//■_(γ-Fe),■_(TiN)//■_(γ-Fe).Because of the smallest interfacialmisfit,the secondary close-packed lane {100} of TiN preferentially combines with the close-packed plane {111} of γ-Fe during the precipitation in order to minimize the interface energy.After nucleation,the TiN precipitates exhibit cubic appearance due to the fact that the TiN has a FCC structure with rock salt type structure.This study provides reference for the material design of the austenitic high-manganese steels with excellent yield strength.展开更多
基金the funding support from the National Key Research and Development Program of China(2019YFE0123400)the Tianjin Distinguished Young Scholars Fund(20JCJQJC00260)+4 种基金the Major Science and Technology Project of Anhui Province(202203f07020007)the Anhui Conch Group Co.,Ltdthe“111”Project(B16027)the funding support from the Natural Science Foundation of China(22209081)the fellowship of China Postdoctoral Science Foundation(2021M690082)。
文摘Developing bimetallic catalysts is an effective strategy for enhancing the activity and selectivity of electrochemical CO_(2) reduction reactions,where understanding the structure-activity relationship is essential for catalyst design.Herein,we prepared two Cu-Ag bimetallic catalysts with Ag nanoparticles attached to the top or the bottom of Cu nanowires.When tested in a flow cell,the Cu-Ag catalyst with Ag nanoparticles on the bottom achieved a faradaic efficiency of 54%for ethylene production,much higher than the catalyst with Ag nanoparticles on the top.The catalysts were further studied in the H-cell and zero-gap MEA cell.It was found that placing the two metals in the intensified reaction zone is crucial to triggering the tandem reaction of bimetallic catalysts.Our work elucidates the structure-activity relationship of bimetallic catalysts for CO_(2) reduction and demonstrates the importance of considering both catalyst structures and cell characteristics to achieve high activity and selectivity.
基金Project (2007CB613807) supported by the National Basic Research Program of ChinaProject (35-TP-2009) supported by the Fund of the State Key Laboratory of Solidification Processing in NWPU,ChinaProject (51075333) supported by the National Natural Science Foundation of China
文摘The isothermal compression tests were carried out in the Thermecmastor-Z thermo-simulator at temperatures of 800, 850, 900, 950, 1000 and 1050 ℃ and the strain rates of 0.01, 0.1, 1 and 10 s-1. The influence of deformation temperature and strain rate on the flow stress of Ti-6Al-2Zr-IMo-IV alloy was studied. Based on the experimental data sets, the high temperature deformation behavior of Ti-6A1-2Zr-IMo-IV alloy was presented using the intelligent method of artificial neural network （ANN）. The results indicate that the predicted flow stress values by ANN model is quite consistent with the experimental results, which implies that the artificial neural network is an effective tool for studying the hot deformation behavior of the present alloy. In addition, the development of graphical user interface is implemented using Visual Basic programming language.
文摘In this paper, CoMFA method was applied to study the 3D QSAR on a series of 3 anilinomethylene 6 alkyl (aryl) 5,6 2H dihydropyran 2, 4 dione compounds, which were designed and synthesized referring to the natural toxic Alternaric acid structure. The results displayed the information on modification of primary molecules and further synthesis of new bioactive compounds.
文摘Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carboxylic acids to study the relationship betweentheir structure and the affinity for the glycine site of the NMDA receptor. Result Hie coefficientsof cross-validation q^2 and non cross-validation r^2 for the model established by the study are0.744 and 0.993, respectively, the value of variance ratio F is 261.343, and standard error estimate(SE) is 0.039. Conclusion These values indicate that the CoMFA model may have a good prediction forthe activity of C-3 substituted 4, 6-dichloroin-dole-2-carboxylic acids. As a consequence, thepredicted activity values of new designed compounds supports our conclusion from the model.
文摘By investigating the types of 371 non-English major freshmen's use of mother-tongue-reliance strategies in English languagelearning,the study showed that students' use of mother-tongue-reliance strategies would vary significantly with their different L2 profi-ciency.And it was negatively correlated with L2 proficiency.And the study discussed the implications to guide English language teach-ing and learning.
基金supported by the China Scholarship Council (CSC [2006] No. 3085)
文摘The Two-dimensional Quantitative Structure-activity Relationship （2D-QSAR） of a series of novel norcantharidin analogues, which exhibit hnhibitory activities of protein phosphatase 1 and 2A （PP1 and PP2A）, has been studied with a combined method of ab initio （I/F）, molecular mechanics （MM＋） and statistics. The established 2D-QSAR model （Eq. 1） for PP1 shows a reasonable regressive performance （R2= 0.749）, and the hydrophobic property of this molecule plays a decisive role in determining the inhibitory activity of PP1. In addition, the established 2D-QSAR model （Eq. 2） for PP2A also shows an acceptable regressive performance （R2= 0.701）, and the dipole moment of the molecule determines the inhibitory activity of PP2A.
基金supported by the National Natural Science Foundation of China (No. 30500339)Natural Science Foundation of Zhejiang Province (NO.Y407308)the Sprout Talented Project Program of Zhejiang Province (No. 2008R40G2020019)
文摘Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.
文摘A series of novel derivatives of 4, 5, 6, 7-tetrahydrothieno [3,2-c] pyridine were synthesized and structurally characterized by 1H NMR and MS. Their in vivo anti-platelet aggregation activities were evaluated. A 3D-QSAR was performed using the CoMFA and the CoMSIA. This model provided useful guidelines for novel anti-platelet thienopyridines design.
基金supported by the National Natural Science Foundation of China(No.81270054)the program for Outstanding Young Teachers in Higher Education Institutions of Guangdong Province(No.Yq2013045)
文摘Enhancer of Zeste homolog 2（EZH2） is closely correlated with malignant tumor and regarded as a promising target to treat B-cell lymphoma. In our research, the molecular docking and three-dimensional quantitative structure-activity relationships（3D-QSAR） studies were performed on a series of pyridone-based EZH2 compounds. Molecular docking allowed us to study the critical interactions at the binding site of EZH2 protein with inhibitors and identify the practical conformations of ligands in binding pocket. Moreover, the docking-based alignment was applied to derive the reliable 3D-QSAR models. Comparative molecular field analysis（CoMFA） and comparative molecular similarity indices analysis（CoMSIA） provided available ability of visualization. All the derived 3D-QSAR models were considered to be statistically significant with respect to the internal and external validation parameters. For the CoMFA model, q^2 = 0.649, r^2 = 0.961 and r^2 pred = 0.877. For the CoMSIA model, q^2 = 0.733, r^2 = 0.980 and r^2 pred = 0.848. With the above arguments, we extracted the correlation between the biological activity and structure. Based on the binding interaction and 3D contour maps, several new potential inhibitors with higher biological activity predicted were designed, which still awaited experimental validation. These theoretical conclusions could be helpful for further research and exploring potential EZH2 inhibitors.
基金the financial support from the National Natural Science Foundation of China(Grant No.U1604251)the Major Scientific and Technological Project of Luoyang,China(Grant No.2001017A)。
文摘A Mn18Cr2 steel containing TiN precipitates was fabricated by vacuum induction melting.The morphology of TiN precipitates and the interface orientation relationship between TiN and γ-Fe were characterized by means of SEM,TEM and SAED,and the formation mechanism of TiN precipitates in Mn18Cr2 steel was clarified.Results show that the TiN precipitates are more likely to exhibit a cubic-shaped morphology and form both within the grain and at the grain boundary of γ-Fe.The interface orientation relationship between TiN and γ-Fe is determined as follows:(100)_(TiN)//■_(γ-Fe),■_(TiN)//■_(γ-Fe).Because of the smallest interfacialmisfit,the secondary close-packed lane {100} of TiN preferentially combines with the close-packed plane {111} of γ-Fe during the precipitation in order to minimize the interface energy.After nucleation,the TiN precipitates exhibit cubic appearance due to the fact that the TiN has a FCC structure with rock salt type structure.This study provides reference for the material design of the austenitic high-manganese steels with excellent yield strength.
