Heteroatom-doped carbon has been demonstrated to be one of the most promising non-noble metal catalysts with high catalytic activity and stability through the modification of the electronic and geometric structures.In...Heteroatom-doped carbon has been demonstrated to be one of the most promising non-noble metal catalysts with high catalytic activity and stability through the modification of the electronic and geometric structures.In this study,we develop a novel solvent method to prepare interconnected N,S co-doped three-dimensional（3D）carbon networks with tunable nanopores derived from an asso-ciated complex based on melamine and sodium dodecylbenzene sulfonate（SDBS）.After the intro-duction of silica templates and calcination,the catalyst exhibits 3D networks with interconnected 50-nm pores and partial graphitization.With the increase of the number of Lewis base sites caused by the N doping and change of the carbon charge and spin densities caused by the S doping,the designed N,S co-doped catalyst exhibits a similar electrochemical activity to that of the commercial 20-wt%Pt/C as an oxygen reduction reaction catalyst.In addition,in an aluminum-air battery,the proposed catalyst even outperforms the commercial 5-wt%Pt/C catalyst.Both interconnected porous structures and synergistic effects of N and S contribute to the superior catalytic perfor-mance.This study paves the way for the synthesis of various other N-doped and co-doped carbon materials as efficient catalysts in electrochemical energy applications.展开更多
To systematically study the effect of Lewis acid sites(LASs)and Lewis base sites(LBSs)in MOF materials for the CO_(2)cycloaddition reaction,four isomorphous copper polyhedron-based MOFs(Cu-PMOFs),JLU-Liu20,JLU-Liu21,J...To systematically study the effect of Lewis acid sites(LASs)and Lewis base sites(LBSs)in MOF materials for the CO_(2)cycloaddition reaction,four isomorphous copper polyhedron-based MOFs(Cu-PMOFs),JLU-Liu20,JLU-Liu21,JLU-Liu22 and JLU-Liu46 with different amounts of LASs and LBSs were selected to investigate their CO_(2)fixation catalytic performance.It is commendable that the catalytic capabilities of the four Cu-PMOFs exceed that of most reported MOF-based catalysts.展开更多
There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of wa...There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.展开更多
The method on accounting the site-based cost was erected in this paper. It is well adapted to the actual production characters of China’s coal industry. The principle and detailed method of determining the boundaries...The method on accounting the site-based cost was erected in this paper. It is well adapted to the actual production characters of China’s coal industry. The principle and detailed method of determining the boundaries among costing sites were put forward. The code structure with 7-digit number of the costing sites was also introduced. The accounting method of the site-based cost and the principle of designing the spatial characters database were expounded at the same time.展开更多
The site occupations of the alloying elements of O phase in Ti 2AlNb based intermetallics are clarified. The ordering behaviours of the O phase in Ti y Al z Nb( y ≥ 25%, mole fraction) orthorhombic alloys are also in...The site occupations of the alloying elements of O phase in Ti 2AlNb based intermetallics are clarified. The ordering behaviours of the O phase in Ti y Al z Nb( y ≥ 25%, mole fraction) orthorhombic alloys are also investigated with a Bragg Williams model. In the temperature range where the O phases exist, the order parameters change with the alloy composition and temperature continuously, and the first order transition character is very "展开更多
Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and p...Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and products formation from the oxidation of the primary and the secondary hydroxyl groups are understood by combining the model calculations and DFT calculations, aiming to discriminate the corresponding dominant Pt active sites. The Pt(100) facet is demonstrated to be the dominant active sites for the glycerol conversion and the products formation from the two routes. The insights revealed here could shed new light on fundamental understanding of the Pt particle size effects and then guiding the design and optimization of Pt-catalyzed base-free oxidation of glycerol toward targeted products.展开更多
该文阐述了近期液化震害特点,根据技术体系属性要求,对国际先进的风险管理体系、既有工程风险管理技术体系以及地震工程性态设计技术体系的优缺点进行了对比分析,提出了抗液化性态设计的基本内涵,构建了抗液化性态设计(performance-base...该文阐述了近期液化震害特点,根据技术体系属性要求,对国际先进的风险管理体系、既有工程风险管理技术体系以及地震工程性态设计技术体系的优缺点进行了对比分析,提出了抗液化性态设计的基本内涵,构建了抗液化性态设计(performance-based design for liquefaction resistance,PBDLR)技术体系框架和流程,并分析了体系中的若干要点。所构建的PBDLR技术体系,考虑了液化震害特点,吸纳了国际上先进的风险管理体系和既有地震工程性态设计技术体系的优点,就液化设防标准、液化设防投资标准、液化概率评价和考虑液化概率的地基处理措施等关键点提出了解决方案,使风险和性态理念下抗液化设计技术的发展有了明确的纲领和准则,对液化理论研究与抗液化性态设计技术发展将起到指导、控制和协调的重要作用,亦可为其他灾种灾害防治技术体系的制定提供参考。展开更多
The doping effects on the stacking fault energies(SFEs),including the superlattice intrinsic stacking fault and superlattice extrinsic stacking fault,were studied by first principles calculation of the/phase in the Ni...The doping effects on the stacking fault energies(SFEs),including the superlattice intrinsic stacking fault and superlattice extrinsic stacking fault,were studied by first principles calculation of the/phase in the Ni-based superalloys.The formation energy results show that the main alloying elements in Ni-based superalloys,such as Re,Cr,Mo,Ta,and W,prefer to occupy the Al-site in Ni3 AI,Co shows a weak tendency to occupy the Ni-site,and Ru shows a weak tendency to occupy the Al-site.The SFE results show that Co and Ru could decrease the SFEs when added to fault planes,while other main elements increase SFEs.The double-packed superlattice intrinsic stacking fault energies are lower than superlattice extrinsic stacking fault energies when elements(except Co) occupy an Al-site.Furthermore,the SFEs show a symmetrical distribution with the location of the elements in the ternary model.A detailed electronic structure analysis of the Ru effects shows that SFEs correlated with not only the symmetry reduction of the charge accumulation but also the changes in structural energy.展开更多
基金supported by the National Natural Science Foundation of China (51674297)the Natural Science Foundation of Hunan Province (2016JJ2137)the Fundamental Research Funds for the Central Universities of Central South University (2015cx001)~~
文摘Heteroatom-doped carbon has been demonstrated to be one of the most promising non-noble metal catalysts with high catalytic activity and stability through the modification of the electronic and geometric structures.In this study,we develop a novel solvent method to prepare interconnected N,S co-doped three-dimensional（3D）carbon networks with tunable nanopores derived from an asso-ciated complex based on melamine and sodium dodecylbenzene sulfonate（SDBS）.After the intro-duction of silica templates and calcination,the catalyst exhibits 3D networks with interconnected 50-nm pores and partial graphitization.With the increase of the number of Lewis base sites caused by the N doping and change of the carbon charge and spin densities caused by the S doping,the designed N,S co-doped catalyst exhibits a similar electrochemical activity to that of the commercial 20-wt%Pt/C as an oxygen reduction reaction catalyst.In addition,in an aluminum-air battery,the proposed catalyst even outperforms the commercial 5-wt%Pt/C catalyst.Both interconnected porous structures and synergistic effects of N and S contribute to the superior catalytic perfor-mance.This study paves the way for the synthesis of various other N-doped and co-doped carbon materials as efficient catalysts in electrochemical energy applications.
基金supported by the National Natural Science Foundation of China(No.21771078 and 21621001)the 111 Project(B17020)the National Key Research and Development Program of China(2016YFB0701100).
文摘To systematically study the effect of Lewis acid sites(LASs)and Lewis base sites(LBSs)in MOF materials for the CO_(2)cycloaddition reaction,four isomorphous copper polyhedron-based MOFs(Cu-PMOFs),JLU-Liu20,JLU-Liu21,JLU-Liu22 and JLU-Liu46 with different amounts of LASs and LBSs were selected to investigate their CO_(2)fixation catalytic performance.It is commendable that the catalytic capabilities of the four Cu-PMOFs exceed that of most reported MOF-based catalysts.
文摘There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.
文摘The method on accounting the site-based cost was erected in this paper. It is well adapted to the actual production characters of China’s coal industry. The principle and detailed method of determining the boundaries among costing sites were put forward. The code structure with 7-digit number of the costing sites was also introduced. The accounting method of the site-based cost and the principle of designing the spatial characters database were expounded at the same time.
文摘The site occupations of the alloying elements of O phase in Ti 2AlNb based intermetallics are clarified. The ordering behaviours of the O phase in Ti y Al z Nb( y ≥ 25%, mole fraction) orthorhombic alloys are also investigated with a Bragg Williams model. In the temperature range where the O phases exist, the order parameters change with the alloy composition and temperature continuously, and the first order transition character is very "
基金financially supported by the Natural Science Foundation of China (21776077)the Shanghai Natural Science Foundation (17ZR1407300 and 17ZR1407500)+5 种基金the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learningthe Shanghai Rising-Star Program (17QA1401200)the Open Project of State Key Laboratory of Chemical Engineering (SKLChe-15C03)the State Key Laboratory of Organic– Inorganic Composites (oic-201801007)the Fundamental Research Funds for the Central Universities (222201718003)the 111 Project of the Ministry of Education of China (B08021)
文摘Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and products formation from the oxidation of the primary and the secondary hydroxyl groups are understood by combining the model calculations and DFT calculations, aiming to discriminate the corresponding dominant Pt active sites. The Pt(100) facet is demonstrated to be the dominant active sites for the glycerol conversion and the products formation from the two routes. The insights revealed here could shed new light on fundamental understanding of the Pt particle size effects and then guiding the design and optimization of Pt-catalyzed base-free oxidation of glycerol toward targeted products.
文摘该文阐述了近期液化震害特点,根据技术体系属性要求,对国际先进的风险管理体系、既有工程风险管理技术体系以及地震工程性态设计技术体系的优缺点进行了对比分析,提出了抗液化性态设计的基本内涵,构建了抗液化性态设计(performance-based design for liquefaction resistance,PBDLR)技术体系框架和流程,并分析了体系中的若干要点。所构建的PBDLR技术体系,考虑了液化震害特点,吸纳了国际上先进的风险管理体系和既有地震工程性态设计技术体系的优点,就液化设防标准、液化设防投资标准、液化概率评价和考虑液化概率的地基处理措施等关键点提出了解决方案,使风险和性态理念下抗液化设计技术的发展有了明确的纲领和准则,对液化理论研究与抗液化性态设计技术发展将起到指导、控制和协调的重要作用,亦可为其他灾种灾害防治技术体系的制定提供参考。
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFB0701502).
文摘The doping effects on the stacking fault energies(SFEs),including the superlattice intrinsic stacking fault and superlattice extrinsic stacking fault,were studied by first principles calculation of the/phase in the Ni-based superalloys.The formation energy results show that the main alloying elements in Ni-based superalloys,such as Re,Cr,Mo,Ta,and W,prefer to occupy the Al-site in Ni3 AI,Co shows a weak tendency to occupy the Ni-site,and Ru shows a weak tendency to occupy the Al-site.The SFE results show that Co and Ru could decrease the SFEs when added to fault planes,while other main elements increase SFEs.The double-packed superlattice intrinsic stacking fault energies are lower than superlattice extrinsic stacking fault energies when elements(except Co) occupy an Al-site.Furthermore,the SFEs show a symmetrical distribution with the location of the elements in the ternary model.A detailed electronic structure analysis of the Ru effects shows that SFEs correlated with not only the symmetry reduction of the charge accumulation but also the changes in structural energy.
