Purpose： This paper aims to gain an insight into the disciplinary structure of nanoscience ＆ nanotechnology （N＆N）： What is the disciplinary network of N＆N like？ Which disciplines are being integrated into N＆N...Purpose： This paper aims to gain an insight into the disciplinary structure of nanoscience ＆ nanotechnology （N＆N）： What is the disciplinary network of N＆N like？ Which disciplines are being integrated into N＆N over time？ For a specific discipline, how many other disciplines have direct or indirect connections with it？ What are the distinct subgroups of N＆N at different evolutionary stages？ Such critical issues are to be addressed in this paper. Design/methodology/approach： We map the disciplinary network structure of N＆N by employing the social network analysis tool, Netdraw, identifying which Web of Science Categories （WCs） mediate nbetweenness centrality in different stages of nano development. Cliques analysis embedded in the Ucinet program is applied to do the disciplinary cluster analysis in the study according to the path of ＂Network-Subgroup-Cliques,＂ and a tree diagram is selected as the visualizing type. Findings： The disciplinary network structure reveals the relationships among different disciplines in the N＆N developing process clearly, and it is easy for us to identify which disciplines are connected with the core ＂N＆N＂ directly or indirectly. The tree diagram showing N＆N related disciplines provides an interesting perspective on nano research and development （R＆D） structure. Research limitations： The matrices used to draw the N＆N disciplinary network are the original ones, and normalized matrix could be tried in future similar studies. Practical implications： Results in this paper can help us better understand the disciplinary structure of N＆N, and the dynamic evolution of N＆N related disciplines over time. The findings could benefit R＆D decision making. It can support policy makers from government agencies engaging in science and technology （S＆T） management or S＆T strategy planners to formulate efficient decisions according to a perspective of converging sciences and technologies. Originality/value： The novelty of this study lies in mapping the disciplinary network structure of N＆N clearly, identifying which WCs have a mediating effect in different developmental stages （especially analyzing clusters among disciplines related to N＆N, revealing close or distant relationships among distinct areas pertinent to N＆N）.展开更多
The crystal and molecular structures of O-ethyl-N-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate were determined by X-ray crystallography. It crystallizes in the orthorhombic system with space group P2(1)2(1)2(...The crystal and molecular structures of O-ethyl-N-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate were determined by X-ray crystallography. It crystallizes in the orthorhombic system with space group P2(1)2(1)2(1), lattice parameters a=0.90636(18) nm, b=0.94716(19) nm, c=2.1855(4) nm, V=1.8762(7) nm 3, and Z=4. All the substituents are in equatorial positions. There are four intramolecular interactions, each forming a five-membered ring. The molecules are linked by interactions to form three-dimensional framework. Atoms O6 and O8 show positional disorder.展开更多
In present work, the metal-ceramic interpenetrating composites (IPCs) as AlSi11/ Si3N4 are fabricated by infiltrating technique. IPCs exhibit special characterization of brittle ceramic reinforced phase introduced by ...In present work, the metal-ceramic interpenetrating composites (IPCs) as AlSi11/ Si3N4 are fabricated by infiltrating technique. IPCs exhibit special characterization of brittle ceramic reinforced phase introduced by ductile metal matrix phase. During the sliding wear processes, IPCs exhibit four wear mechanism such as initial adhesive wear, mixed adhesive and abrasive wear, adhesive wear and final abrasive wear. Reinforcements inhibit plastic flow and restrict propagation of wear cracks. Increase in the volume fraction of reinforcement leads to improvement in the wear resistance. Under higher load and lower round speed conditions, the friction coefficients are lower than that of relative conditions.展开更多
With N,N′ bis(benzimidazol 2 yl methyl)amine as the ligand, a novel Cu(II) dinuclear complex was synthesized as a mimetic compound of superoxide dismutase (SOD). The complex was characterized with element ana...With N,N′ bis(benzimidazol 2 yl methyl)amine as the ligand, a novel Cu(II) dinuclear complex was synthesized as a mimetic compound of superoxide dismutase (SOD). The complex was characterized with element analysis, UV and IR spectra. The crystal structure was determined by using X ray diffraction analysis. The crystal structure shows that Cu(II) and its coordinated atoms construct distorted octahedron configuration with oxygen atoms of (ClO - 4) s in the axial directions. The coordinated cations are linked by (ClO - 4) s to form nonplanar sheets. All sheets are linked together into three dimensional network by the intermolecular hydrogen bonds. The result of the activity assay indicates that the complex does have certain biological activity.展开更多
Two novel one- and two-dimensional network structure bismuth(III) complexes with N,N-di(2-hydroxylethyl)- aminodithiocarboxylate, {Bi[S2CN(C2H4OH)2]2[1,10-Phen]2(NO3)}3H2O (1) and {Bi[S2CN(C2H4OH)2]3}2 (2) were synthe...Two novel one- and two-dimensional network structure bismuth(III) complexes with N,N-di(2-hydroxylethyl)- aminodithiocarboxylate, {Bi[S2CN(C2H4OH)2]2[1,10-Phen]2(NO3)}3H2O (1) and {Bi[S2CN(C2H4OH)2]3}2 (2) were synthesized. Their crystal and molecular structures were determined by X-ray single crystal diffraction analysis. The crystal 1 belongs to monoclinic system with space group C2/c, a=1.6431(7) nm, b=2.4323(10) nm, c=1.2646(5) nm, =126.237(5)o, Z=4, V=4.076(3) nm3, Dc=1.757 Mg/m3, =4.598 mm-1, F(000)=2156, R=0.0211, wR=0.0369. The structure shows a distorted square antiprism configuration with eight-coordination for the central Bi atom. The one-dimensional chain structure was formed by H-bonding interaction between hydroxyl group of N,N-di(2-hydroxylethyl)aminodithiocarboxylate ligands and crystal water. The crystal 2 belongs to monoclinic system with space group P2(1)/c, a=1.1149(4) nm, b=2.1274(8) nm, c=2.2107(8) nm, =98.325(8), Z=4, V=5.188(3) nm3, Dc=1.920 Mg/m3, =7.315 mm-1, F(000)=2944, R=0.0565, wR=0.0772. The structure shows a distorted square antiprism configuration with eight-coordination for the central Bi atoms. The two-dimensional network structure was formed by H-bonding interaction between adjacent molecules.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Grant No.:71473028)the Project of Dalian University of Technology (DLUT) Educational Reform(Grant No.:ZD201509)
文摘Purpose： This paper aims to gain an insight into the disciplinary structure of nanoscience ＆ nanotechnology （N＆N）： What is the disciplinary network of N＆N like？ Which disciplines are being integrated into N＆N over time？ For a specific discipline, how many other disciplines have direct or indirect connections with it？ What are the distinct subgroups of N＆N at different evolutionary stages？ Such critical issues are to be addressed in this paper. Design/methodology/approach： We map the disciplinary network structure of N＆N by employing the social network analysis tool, Netdraw, identifying which Web of Science Categories （WCs） mediate nbetweenness centrality in different stages of nano development. Cliques analysis embedded in the Ucinet program is applied to do the disciplinary cluster analysis in the study according to the path of ＂Network-Subgroup-Cliques,＂ and a tree diagram is selected as the visualizing type. Findings： The disciplinary network structure reveals the relationships among different disciplines in the N＆N developing process clearly, and it is easy for us to identify which disciplines are connected with the core ＂N＆N＂ directly or indirectly. The tree diagram showing N＆N related disciplines provides an interesting perspective on nano research and development （R＆D） structure. Research limitations： The matrices used to draw the N＆N disciplinary network are the original ones, and normalized matrix could be tried in future similar studies. Practical implications： Results in this paper can help us better understand the disciplinary structure of N＆N, and the dynamic evolution of N＆N related disciplines over time. The findings could benefit R＆D decision making. It can support policy makers from government agencies engaging in science and technology （S＆T） management or S＆T strategy planners to formulate efficient decisions according to a perspective of converging sciences and technologies. Originality/value： The novelty of this study lies in mapping the disciplinary network structure of N＆N clearly, identifying which WCs have a mediating effect in different developmental stages （especially analyzing clusters among disciplines related to N＆N, revealing close or distant relationships among distinct areas pertinent to N＆N）.
文摘The crystal and molecular structures of O-ethyl-N-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate were determined by X-ray crystallography. It crystallizes in the orthorhombic system with space group P2(1)2(1)2(1), lattice parameters a=0.90636(18) nm, b=0.94716(19) nm, c=2.1855(4) nm, V=1.8762(7) nm 3, and Z=4. All the substituents are in equatorial positions. There are four intramolecular interactions, each forming a five-membered ring. The molecules are linked by interactions to form three-dimensional framework. Atoms O6 and O8 show positional disorder.
文摘In present work, the metal-ceramic interpenetrating composites (IPCs) as AlSi11/ Si3N4 are fabricated by infiltrating technique. IPCs exhibit special characterization of brittle ceramic reinforced phase introduced by ductile metal matrix phase. During the sliding wear processes, IPCs exhibit four wear mechanism such as initial adhesive wear, mixed adhesive and abrasive wear, adhesive wear and final abrasive wear. Reinforcements inhibit plastic flow and restrict propagation of wear cracks. Increase in the volume fraction of reinforcement leads to improvement in the wear resistance. Under higher load and lower round speed conditions, the friction coefficients are lower than that of relative conditions.
基金NationalNaturalScienceFoundationofTianjinEducationCommittee (No .972 0 2 )
文摘With N,N′ bis(benzimidazol 2 yl methyl)amine as the ligand, a novel Cu(II) dinuclear complex was synthesized as a mimetic compound of superoxide dismutase (SOD). The complex was characterized with element analysis, UV and IR spectra. The crystal structure was determined by using X ray diffraction analysis. The crystal structure shows that Cu(II) and its coordinated atoms construct distorted octahedron configuration with oxygen atoms of (ClO - 4) s in the axial directions. The coordinated cations are linked by (ClO - 4) s to form nonplanar sheets. All sheets are linked together into three dimensional network by the intermolecular hydrogen bonds. The result of the activity assay indicates that the complex does have certain biological activity.
基金Project supported by the National Natural Science Foundation of China (No. 20271025) and the Natural Science Foundation of Shandong Province (No. L2003B01).
文摘Two novel one- and two-dimensional network structure bismuth(III) complexes with N,N-di(2-hydroxylethyl)- aminodithiocarboxylate, {Bi[S2CN(C2H4OH)2]2[1,10-Phen]2(NO3)}3H2O (1) and {Bi[S2CN(C2H4OH)2]3}2 (2) were synthesized. Their crystal and molecular structures were determined by X-ray single crystal diffraction analysis. The crystal 1 belongs to monoclinic system with space group C2/c, a=1.6431(7) nm, b=2.4323(10) nm, c=1.2646(5) nm, =126.237(5)o, Z=4, V=4.076(3) nm3, Dc=1.757 Mg/m3, =4.598 mm-1, F(000)=2156, R=0.0211, wR=0.0369. The structure shows a distorted square antiprism configuration with eight-coordination for the central Bi atom. The one-dimensional chain structure was formed by H-bonding interaction between hydroxyl group of N,N-di(2-hydroxylethyl)aminodithiocarboxylate ligands and crystal water. The crystal 2 belongs to monoclinic system with space group P2(1)/c, a=1.1149(4) nm, b=2.1274(8) nm, c=2.2107(8) nm, =98.325(8), Z=4, V=5.188(3) nm3, Dc=1.920 Mg/m3, =7.315 mm-1, F(000)=2944, R=0.0565, wR=0.0772. The structure shows a distorted square antiprism configuration with eight-coordination for the central Bi atoms. The two-dimensional network structure was formed by H-bonding interaction between adjacent molecules.
