Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
Add more filters










Database
Language
Publication year range
1.
ACS Omega ; 7(8): 6935-6943, 2022 Mar 01.
Article in English | MEDLINE | ID: mdl-35252685

ABSTRACT

In-depth insights into the chemical composition and structural information of coal are an effective way to improve the efficiency of coal utilization. Laser-induced acoustic desorption coupling with vacuum ultraviolet photoionization time-of-flight mass spectrometry (LIAD-VUVPI-TOFMS) was applied to structural characterization of cyclohexane extracts of low-rank Naomaohu coal. The characterization of four types (12 model compounds) of mixed coal model compounds (three compounds per category)-saturated hydrocarbons, substitute aromatic hydrocarbons, aromatic hydrocarbons, and aromatic heteroatom rings-demonstrated that the approach can provide intact molecular weight information. The cyclohexanone extract (E CYC) was obtained by microwave-assisted extraction and separated into four group components (F1-4) by column chromatography to achieve component classification and simplify analysis. The molecular weight and structure were obtained by LIAD-VUVPI-TOFMS and synchronous fluorescence spectroscopy, combined with microwave-assisted extraction and column chromatography to separate product characteristics. Chemical components of a total of 248 species were observed, of which 46 are derived from aliphatic hydrocarbons embedded in the coal skeleton structure, 132 species are derived from aromatic hydrocarbons embedded in the coal skeleton structure, 61 are derived from possible coal skeleton units (compounds have obvious stacking and bonding effects), and 9 could not be determined (aromatic hydrocarbons or a possible coal skeleton structure unit).

2.
Sci Rep ; 7(1): 17709, 2017 12 18.
Article in English | MEDLINE | ID: mdl-29255141

ABSTRACT

A novel NiO/Ni/RGO three-dimensional core-shell architecture consisting of Ni nanoparticles as core, NiO as shell and reduced graphene oxide (RGO) as conductivity layer, has been constructed by redox reactions with hydrothermal method and heat treatment. High density arrayed nickel nanoparticles (20 nm diameter) semi-coated by a 3 nm thick layer of NiO are evenly distributed on the surface of graphene. This elaborate design not only uses abundant NiO surfaces to provide a wealth of active sites, but also bridges electrochemical active NiO shell and graphene by Ni core to construct an interconnected 3D conductive network. Since both electrochemical activity and excellent conductivity are reserved in this Ni/NiO core-shell/graphene layer 3D structure, the as-prepared electrode material exhibits an extremely high specific capacitance (2048.3 F g-1 at current density of 1 A g-1) and excellent cycle stability (77.8% capacitance retention after 10000 cycles at current density of 50 A g-1). The novel method presented here is easy and effective and would provide reference for the preparation of other high performance supercapacitor electrodes.

3.
Sci Rep ; 7(1): 3021, 2017 06 08.
Article in English | MEDLINE | ID: mdl-28596559

ABSTRACT

A facile one-step hydrothermal reaction was employed to synthesis an integrated bifunctional composite composed by a network structure of ZnS/ZnO/Ni(OH)2 nanosheets with ZnS/ZnO nanospheres in situ growing on Ni foam. The synergistic effect of these three substances make the composite having both improved electrochemical performances and photocatalytic activity. The ZnS/ZnO/Ni(OH)2-4mmol shows a high specific capacitance of 1173.8 F g-1 at 1 A g-1, as well as good rate capability and relatively stable cyclability. Using as photocatalyst, the methyl orange dye in solution can be completely decomposed under ultraviolet-visible radiation in about 80 min. And the composite is easy to be repeatedly used because bulk Ni foam was used as a carrier. Such a bifunctional composite material provides a new insight for energy storage and utilization as well as the water pollution treatment.

4.
Chemistry ; 23(17): 4128-4136, 2017 Mar 23.
Article in English | MEDLINE | ID: mdl-28133889

ABSTRACT

A novel Ni foam-Ni3 S2 @Ni(OH)2 -graphene sandwich-structured electrode (NF-NN-G) with high areal mass loading (8.33 mg cm-2 ) has been developed by sulfidation and hydrolysis reactions. The conductivity of Ni3 S2 and Ni(OH)2 were both improved. The upper layer of Ni(OH)2 , covered with a thin graphene film, is formed in situ from the surface of the lower layer of Ni3 S2 , whereas the Ni3 S2 grown on Ni foam substrate mainly acts as a rough support bridging the Ni(OH)2 and Ni foam. The graphene stabilized the Ni(OH)2 and the electrochemical properties were effectively enhanced. The as-synthesized NF-NN-G-5mg electrode shows a high specific capacitance (2258 F g-1 at 1 A g-1 or 18.81 F cm-2 at 8.33 mA cm-2 ) and an outstanding rate property (1010 F g-1 at 20 Ag-1 or 8.413 F cm-2 at 166.6 mA cm-2 ). This result is around double the capacitance achieved in previous research on Ni3 S2 @Ni(OH)2 /3DGN composites (3DGN=three-dimensional graphene network). In addition, the as-fabricated NF-NN-G-5mg composite electrode has an excellent cycle life with no capacitance loss after 3000 cycles, indicating a potential application as an efficient electrode.

5.
Mater Sci Eng C Mater Biol Appl ; 57: 14-23, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26354235

ABSTRACT

Porous biocompatible hydroxyapatite (HAP) nanorods of various sizes were synthesized by the combination of chemical precipitation and hydrothermal method without the use of organic modifiers. The HAP nanorod samples were characterized by powder X-ray diffraction, transmission electron microscopy, and N2 adsorption/desorption techniques. HAP nanorods with average diameters and average lengths ranging from 8.5 to 26.6 nm and from 23.1 to 49.7 nm, respectively, could be controllably synthesized via these methods. Low autoclaving temperature and high pH value favored the formation of relatively small HAP nanorods. The TEM images showed that the nanorods possessed porous structures with average pore diameters ranging from 1.6 to 2.7 nm. These HAP nanoparticles effectively prolonged the release time of 5-fluorouracil up to 24h. The as-synthesized HAP nanorods displayed no cytotoxicity to bone marrow stem cells at low HAP concentration, indicating that these nanorod materials could serve as potential carriers for novel drug release systems.


Subject(s)
Delayed-Action Preparations/chemistry , Durapatite/chemistry , Fluorouracil/chemistry , Nanocapsules/chemistry , Nanopores/ultrastructure , Nanotubes/chemistry , Absorption, Physicochemical , Antimetabolites, Antineoplastic/administration & dosage , Antimetabolites, Antineoplastic/chemistry , Diffusion , Fluorouracil/administration & dosage , Nanocapsules/ultrastructure , Nanotubes/ultrastructure , Organic Chemicals/chemistry , Particle Size , Porosity
6.
Mater Sci Eng C Mater Biol Appl ; 33(6): 3256-62, 2013 Aug 01.
Article in English | MEDLINE | ID: mdl-23706208

ABSTRACT

Different-sized α-calcium sulphate hemihydrate (α-CSH) rods were hydrothermally prepared by converting calcium sulphate dihydrate at 110-140°C in the presence of MgCl2, sodium citrate (CANa), and sodium dodecyl benzene sulfonate (SDBS) as the modifiers. The α-CSH rods with the average diameters and the average lengths in the ranges of 2.6-5.2 and 17.5-33.1 µm, respectively, were tunably prepared. The presence of the modifiers favoured the formation of small-sized α-CSH rods. The effect of the modifiers on decreasing the diameters of α-CSH rods was in an order of SDBS>CANa>MgCl2. The dissolution rates of the different-sized α-CSH rods prepared at 140°C in simulated body fluid were in an order of α-CSH (CANa)>α-CSH (MgCl2)>α-CSH (reference)>α-CSH (SDBS). The naked and small-sized α-CSH rods had high dissolution rates. The adsorption of SDBS on the surfaces of α-CSH rods decreased their dissolution rates.


Subject(s)
Calcium Sulfate/chemistry , Adsorption , Benzenesulfonates/chemistry , Body Fluids/chemistry , Citrates/chemistry , Hot Temperature , Magnesium Chloride/chemistry , Microscopy, Electron, Scanning , Sodium Citrate , X-Ray Diffraction
7.
J Pediatr Orthop B ; 20(2): 84-8, 2011 Mar.
Article in English | MEDLINE | ID: mdl-20975588

ABSTRACT

The sequelae of poliomyelitis are the common causes of leg discrepancy. Tibial lengthening is an effective way to solve this problem but it is associated with a high rate of complications. In this study, we combined the use of humeral nail and external fixator in tibial lengthening with the purpose of reducing lengthening complications. Compared with the cases lengthened by a single-plane external fixator alone, this combined strategy was found to be beneficial in maintaining the tibial alignment. Therefore, it can be recommended as a good technique for tibial lengthening in patients with sequelae of poliomyelitis.


Subject(s)
Bone Nails , External Fixators , Ilizarov Technique , Leg Length Inequality/surgery , Poliomyelitis/surgery , Tibia/surgery , Adolescent , Adult , Female , Humans , Leg Length Inequality/etiology , Leg Length Inequality/rehabilitation , Male , Poliomyelitis/complications , Postoperative Complications , Radiography , Retrospective Studies , Tibia/diagnostic imaging , Tibia/pathology , Treatment Outcome , Young Adult
8.
Int Orthop ; 35(6): 935-40, 2011 Jun.
Article in English | MEDLINE | ID: mdl-20455061

ABSTRACT

Leg discrepancy is common after poliomyelitis. Tibial lengthening is an effective way to solve this problem. It is believed lengthening over a tibial intramedullary nail can provide a more comfortable lengthening process than by the conventional technique. However, patients with sequelae of poliomyelitis typically have narrow intramedullary canals allowing limited space for inserting a tibial intramedullary nail and Kirschner wires. To overcome this problem, we tried using humeral nails instead of tibial nails in the lengthening procedure. In this study, we used humeral nails in 20 tibial lengthening procedures and compared the results with another group of patients who were treated with tibial lengthening over tibial intramedullary nails. The mean consolidation index, percentage of increase and external fixation index did not show significant differences between the two groups. However, less blood loss and shorter operating time were noted in the humeral nail group. More patients encountered difficulty with the inserted intramedullary nail in the tibial nail group procedure. The complications did not show a statistically significant difference between the two techniques on follow-up. In conclusion, we found the humeral nail lengthening technique was more suitable in leg discrepancy patients with sequelae of poliomyelitis.


Subject(s)
Bone Nails , Humerus/surgery , Ilizarov Technique/instrumentation , Leg Length Inequality/surgery , Poliomyelitis/surgery , Tibia/surgery , External Fixators , Female , Humans , Humerus/diagnostic imaging , Humerus/pathology , Leg Length Inequality/etiology , Male , Poliomyelitis/complications , Postoperative Complications , Radiography , Retrospective Studies , Tibia/diagnostic imaging , Tibia/pathology , Treatment Outcome , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL
...