Showing papers by "Nanjing Tech University published in 2003"
TL;DR: The synthesis of the faceted single-crystalline h-AlN nanotubes with the length of a few micrometers and diameters from 30 to 80 nm provides an ideal substrate for the construction of GaN-based nanoheterostructures in future nanoelectronics.
Abstract: The synthesis of the faceted single-crystalline h-AlN nanotubes with the length of a few micrometers and diameters from 30 to 80 nm is first reported. This provides an ideal substrate for the construction of GaN-based nanoheterostructures in future nanoelectronics. The experimental results suggest the further extensive experimental and theoretical studies on the promising nonlayered nanotubular structures.
312 citations
TL;DR: Hexagonal AlN (h-AlN) nanowires with an average diameter of around 15 nm have been prepared by an extended vapor-liquid-solid growth technique and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive Xray analysis, Raman spectroscopy and field emission measurements.
Abstract: Hexagonal AlN (h-AlN) nanowires with an average diameter of around 15 nm have been prepared by an extended vapor–liquid–solid growth technique and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray analysis, Raman spectroscopy and field emission measurements. This preparation is a rather simple route for bulk fabrication of h-AlN nanowires. The promising field emission property observed for h-AlN nanowires points to the important application potential of this material.
119 citations
TL;DR: Ion-exchanged Na beta zeolite with Fe2+ and Co2+ cations shows high catalytic activity at room temperature in phenol hydroxylation with H2O2, where the conversion of phenol is ca.
117 citations
TL;DR: In this article, a new kind of alkali-slag-red mud cementitious (ASRC) material, with both high early and ultimate strength and excellent resistance against chemical attacks, has been developed by the introduction of composite solid alkali activator into slagred mud mixture system.
113 citations
TL;DR: Regular stibnite (Sb(2)S(3) nanorods with diameters of 20-40 nm and lengths of 220-350 nm have been successfully synthesized by a sonochemical method under ambient air from an ethanolic solution containing antimony trichloride and thioacetamide.
Abstract: Regular stibnite (Sb2S3) nanorods with diameters of 20−40 nm and lengths of 220−350 nm have been successfully synthesized by a sonochemical method under ambient air from an ethanolic solution containing antimony trichloride and thioacetamide. The as-prepared Sb2S3 nanorods are characterized by employing techniques including X-ray powder diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, and optical diffuse reflection spectroscopy. Microstructural analysis reveals that the Sb2S3 nanorods crystallize in an orthorhombic structure and predominantly grow along the (001) crystalline plane. High-intensity ultrasound irradiation plays an important role in the formation of these Sb2S3 nanorods. The experimental results show that the sonochemical formation of stibnite nanorods can be divided into four steps in sequence: (1) ultrasound-in...
112 citations
TL;DR: Poly(3-hydroxybutyrate) (PHB) was produced by fed-batch cultures of Ralstonia eutropha with phosphate limitation under different glucose concentrations and the highest PHB productivity was obtained with glucose at 9 g l−1.
Abstract: Poly(3-hydroxybutyrate) (PHB) was produced by fed-batch cultures of Ralstonia eutropha with phosphate limitation under different glucose concentrations. When glucose was kept at 2.5 g l−1, cell growth and PHB synthesis were limited due to the shortage of carbon source but a higher PHB content occurred in the cell-growth stage. This shows that a low glucose concentration is favorable for PHB accumulation in R. eutropha. PHB obtained with glucose at 9 g l−1 is 1.6 times that obtained with 40 g l−1. When glucose was in the range of 9 to 40 g l−1, PHB concentration and productivity decreased significantly with the increase of glucose concentration. The highest PHB productivity was obtained with glucose at 9 g l−1.
106 citations
TL;DR: In this paper, the oxide powders were synthesized by solid-state reaction, modified citrate and citrate-EDTA complexing method and showed different grain morphologies.
105 citations
TL;DR: In this paper, the authors introduce some typical cases of industrial applications, which include the equipment for the waste heat recovery and the industrial process equipment, and they also discuss the application of high-temperature heat pipe technology in various industrial fields.
87 citations
TL;DR: In this paper, the incorporation of Zr and its effect on the crystal chemistry, oxygen permeation, and structural stability of SrCo0.6-xZrxO3-δ have been investigated.
Abstract: A new series of SrCo0.4Fe0.6-xZrxO3-δ (0 ≤ x ≤ 0.2) and SrCo0.95-xFexZr0.05O3-δ (0.1 ≤ x ≤ 0.8) oxides were synthesized by the solid-state reaction method. The incorporation of Zr and its effect on the crystal chemistry, oxygen permeation, and structural stability of SrCo0.4Fe0.6-xZrxO3-δ have been investigated. Formation of the solid solutions with the cubic perovskite-type structure was found in the SrCo0.4Fe0.6-xZrxO3-δ oxide system in the range of 0 ≤ x < 0.1. The incorporation of the proper content of Zr into SrCo0.4Fe0.6O3-δ suppressed the oxygen loss at high temperature and could stabilize the cubic structure of perovskite in a low oxygen partial pressure atmosphere, while the oxygen permeability of SrCo0.4Fe0.6-xZrxO3-δ membranes decreased with increasing Zr content. A total of 5 mol % of Zr cation dissolution was considered to be enough for the structural stability without deleteriously affecting the oxygen flux. Meanwhile, an investigation of the effect of the Co content on the oxygen permeation...
65 citations
TL;DR: In this article, a mixed-conducting complex oxide La 2 NiO 4+ δ was prepared by complex sol-gel method by using both ethylene diamine tetraacetic acid (EDTA) and citric acid (Cit) ligands.
47 citations
TL;DR: In this article, X-ray diffraction (XRD) patterns revealed that the BSCF oxides had a perovskite-related structure with mixed-phase, and a small difference in crystal structures was found for membranes prepared at different sintering conditions including Sintering temperature and dwell time.
TL;DR: In this paper, the authors used a practical alkali reactive aggregate-Beijing aggregate to test the long-term effectiveness of LiOH in inhibiting alkali-aggregate reaction (AAR) expansion.
TL;DR: In this paper, a triply-bridged dicopper(II) complex was formulated as [Cu2(dpa)2(μ-Cl)(μ-OH)(μHCOO)]·(ClO4) 1 and two terephthalate anions bridged 2,2′-bipyridine (2,2''-bpy) dicoppers.
TL;DR: In this article, the authors investigate the hydrogen storage properties of HCSed Mg2NiH4 in comparison to the cast Mg 2Ni. The results suggest that the HCS-based Mg-2Ni-H4 has some advantages over the IM product.
TL;DR: In this article, a periodic spindle-unit boron nitride (BN) nanotubes with buglelike open-end tips have been found in the product by nitriding Fe-B nanoparticles at 1100 °C with a mixture of nitrogen and ammonia gas.
Abstract: Periodic spindle-unit boron nitride (BN) nanotubes with buglelike open-end tips have been found in the product by nitriding Fe-B nanoparticles at 1100 °C with a mixture of nitrogen and ammonia gas. The microstructure was well-characterized by high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy (EDX). The diameter of this BN nanotube shows a decreasing tendency along the growth direction. For each spindle unit, the outer diameter decreases steeply and then increases gradually, accompanied by thinning of the wall thickness along the growth direction. Some spindle units are partially occupied by the iron-containing catalyst particles at the hemispherical-like ends. An improved stress-induced sequential growth model has been reasonably deduced accordingly, with which the formation process of this novel BN nanostructure could be well understood.
TL;DR: A mesostructured sulfated zirconia with a large surface area (189 m2/g) has been successfully prepared using a triblock copolymer as a structure-directing agent as discussed by the authors.
Abstract: A mesostructured sulfated zirconia with a large surface area (189 m2/g) has been successfully prepared using a triblock copolymer as a structure-directing agent. The resulting material was characterized by XRD, TEM, nitrogen adsorption, FTIR and TG/DTA, which suggested that the mesostructured sulfated zirconia was tetragonal crystalline. Catalytic testing showed that the mesostructured sulfated zirconia was much more active than conventional sulfated zirconia for n-butane isomerization.
TL;DR: In this article, a growth mechanism mainly based on the space-limited and self-catalytic functions of template channels has been proposed accordingly, and the disordered structure of the carbon nanotubes was assigned to the lattice mismatch between alumina and carbon species.
TL;DR: This work investigated the effect of different kinds of turbulence promoter on flux of ceramic membrane filtration in ceramic membrane bioreactor, finding that the flux under the same operation condition increased about 2.5 times with the introduction of the winding insert.
TL;DR: In this article, high-yield production of quasi-aligned carbon nanotube (CNT) bundles is presented, where benzene was used as the precursor for this catalytic process at a moderate temperature of 650°C over γ-Al2O3-supported Fe-Ni alloy catalysts with different mole ratios.
Abstract: High-yield production of quasi-aligned carbon nanotube (CNT) bundles is presented. Benzene was used as the precursor for this catalytic process at a moderate temperature of 650°C over γ-Al2O3-supported Fe–Ni alloy catalysts with different mole ratios. The maximum yield of high-quality CNTs per hour is even greater than 350% for the optimized catalyst. The products were characterized by thermal gravimetry/differential scanning calorimetry and high-resolution transmission electron microscopy. The results indicated that the products are well graphitized with tube diameters of about 20 nm. Three typical morphologies of the end parts of the CNTs were identified as the open end capped with an Fe–Ni catalyst, the open end without catalyst and the closed end, respectively. A hexagonal carbon-cluster-based growth for this synthesis is suggested.
TL;DR: In this paper, the crystal structure, oxygen permeation and stability of ZrO 2 -promoted SrCo 0.4 Fe 0.6 O 3-δ (SCFZ) were compared with those of SCF.
TL;DR: In this paper, a new polyurethane (PU)/polyacrylate (PA) latex interpenetrating networks (LIPNs) were synthesized using self-emulsification polymerization.
Abstract: Some new kinds of novel polyurethane (PU)/polyacrylate (PA) latex interpenetrating networks (LIPNs) were synthesized. Firstly PU dispersions were synthesized by self-emulsification polymerization. Then PU/PA LIPNs using PU dispersion as the seed were prepared by soap free emulsion polymerization. The effects of different PU/PA ratios, the blending method and the NCO/OH molar ratio of PU components on PU/PA LIPNs performance were also investigated. The structure and properties of PU/PA LIPNs such as mechanical properties, particle size, morphology of the surface were characterized by dynamic mechanical analysis, scanning electron microscopy, and dynamic light scattering. It was found that PU/PA LIPNs can markedly improve the water resistance and the mechanical properties of PU latex much more than those of PU/PA physical blends due to a great deal of interpenetrating and entangling between PU and PA latex. Moreover, the particle size of PU/PA LIPNs is related to the PA content and NCO/OH molar ratio of PU components: the higher the NCO/OH molar ratio in PU dispersions, the larger is the particle size of PU/PA LIPNs, and the average particle size of PU/PA LIPNs becomes larger with an increase in PA content.
TL;DR: By applying a combinatorial method, SAPO-34 was successfully synthesized via vapor-phase transport technique, and the synthesis factors were systematically examined.
TL;DR: In this paper, the anodic aluminum oxide membranes (AAOMs) with nanopores, produced by electrochemical etching method in oxalic/sulphuric/phosphoric acid, were transformed from amorphous phase to crystalline phase by annealing.
TL;DR: In this article, the gallium-promoted sulfated zirconia (GSZ) catalysts were used for the conversion of n-hexane to hexane and the selectivity of 2,2-DMB reached 20%.
TL;DR: In this article, a double metal cyanide (DMC) complex catalyst based on Zn 3 [Fe(CN) 6 ] 2 was synthesized and developed by reaction between aqueous solutions of zinc chloride and potassium hexacyanoferrate with complexing agents to form a precipitate of the DMC compound.
TL;DR: In this paper, a modified feed mode was suggested to prolong the lifetime of the membrane tubes in the POM environment by adding a small amount of oxygen in dilute methane and introducing the mixed gas through the tube side.
Abstract: Tubular perovskite-related yttria-stabilized zirconia (YSZ) promoted SrCo0.4Fe0.6O3-δ oxygen-permeable membrane reactors, packed with NiO/Al2O3 catalyst, were investigated for the partial oxidation of methane (POM) to syngas. When helium-diluted methane was introduced into the tube side of the membrane reactors, the membrane tubes could survive only for 4−6 h. X-ray diffraction (XRD) analyses showed that, at the inlet position of the membrane tubes, serious phase decomposition occurred, which resulted in the breakage of the membrane tubes. A modified feed mode was suggested to prolong the lifetime of the membrane tubes in the POM environment by adding a small amount of oxygen in dilute methane and introducing the mixed gas through the tube side. Under the modified operating mode, the membrane reactors were successfully operated for over 70 h.
TL;DR: In this article, a Ga-promoted tungstated zirconia (GWZ) was prepared by a slurry impregnation method, and the textural properties as well as the acidities of the GWZ were characterized by X-ray powder diffraction (XRD), N2 adsorption, NH3 temperature-programmed desorption (NH3 TPD), microcalorimetry and H2 temperatureprogrammed reduction (H2 TPR).
Abstract: Ga-promoted tungstated zirconia (GWZ) was prepared by a slurry impregnation method. The textural properties as well as the acidities of the Ga-promoted catalysts were characterized by X-ray powder diffraction (XRD), N2 adsorption, NH3 temperature-programmed desorption (NH3 TPD), microcalorimetry and H2 temperature-programmed reduction (H2 TPR). The catalytic behavior of GWZ for n-butane isomerization was studied in the presence of hydrogen. In comparison to tungstated zirconia (WZ), the catalytic activity of the Ga-promoted catalyst was greatly improved. The reason proposed for the higher activity of the Ga-promoted catalysts was that Ga enhances the oxidizing ability of the catalysts.
TL;DR: In this article, two macrocyclic dinuclear zinc(II) complexes have been self-assembled in the presence of pyridine and 2,2′-bipyridine, respectively, to form μ2-OH-bridged bimacrocycles with a Zn4O4 cavity through coordination bonding.
Abstract: Two macrocyclic dinuclear zinc(II) complexes (1a and 1b) have been self-assembled in the presence of pyridine and 2,2′-bipyridine, respectively, to form μ2-OH-bridged bimacrocycles with a Zn4O4 cavity through coordination bonding. The X-ray structural analysis reveals that both compounds {2a: [Zn4La2(OH)2]2(ClO4)2; 2b: [Zn4Lb2(OH)2]2(ClO4)2} have an open-mouthed sandwich-like structure with π−π interactions between parts of two phenyl rings to strengthen two hydroxyl groups connecting the metal atoms in the same direction of the macrocycle. Furthermore, nonclassical C−H···Cl intermolecular interactions have been observed in the crystal of 2b. In addition, the reaction of 1a with quinoline derivatives has yielded novel hydrogen-bond-supported donoracceptor complexes {3a: [Zn2La(H2O)2(C10H9N)2](ClO4)2}. The crystallographic study of the complex containing 2-methylquinoline indicates that two 2-methylquinoline molecules are linked to two coordinating water molecules above and below the macrocyclic framework through O−H···N hydrogen bonds. The 2-methylquinoline plane interacts in a face-to-face fashion with the phenyl ring of adjacent macrocyclic frameworks, forming an ordered arrangement where one macrocycle and two 2-methylquinolines are arrayed alternately with almost the same separation. The interplanar distance mentioned before is ca. 3.6 A. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
TL;DR: In this paper, a mesoporous molecular sieves were used to synthesize carbon nanotubes (CNTs) with Fe- or Fe/Coloading M41S (MCM-41 or MCM-48) as catalysts and benzene as precursor at 650°C.
01 Jan 2003
TL;DR: A modification of the base PSO named fitness sharing particle swarm optimizer (FSPSO) is proposed, which can maintain diversity and avoid convergence to local solution successfully and indicates that FSPSO is an effective strategy on multimodal problem.
Abstract: The particle swarm optimizer (PSO) has exhibited good performance on unimodal problem. But on multimodal problem it tends to suffer from premature convergence. In this paper, we propose a modification of the base PSO named fitness sharing particle swarm optimizer (FSPSO) to solve such problem. Through using fitness sharing technique, FSPSO can maintain diversity and avoid convergence to local solution successfully. Experiment indicates that FSPSO is an effective strategy on multimodal problem.