Hongjun Ni

3D Reverse Modeling and Rapid Prototyping of Complete Denture

An integrated method of reverse engineering and rapid prototyping technology to manufacture complete denture was presented in this paper. Firstly, geometrical surfaces of complete denture were measured by three-dimensional scanner and their point clouds were obtained. Then the point clouds de-noising processing was performed,data was filtered and reduced, the missing data was repaired and triangular surfaces splicing was realized in Geomagic software. 3D model of complete denture was reconstructed in Pro/E software, and the STL file was generated. Finally, the entity model was manufactured by rapid prototyping machine. Through this process the entity model of running-in-period complete denture was manufactured, which can reduce denture repairing time and contribute to health and medical research.

Effect of cryogenic treatment on microstructure and properties of acrylonitrile–butadiene–styrene

In order to improve the mechanical behavior of polymer materials for three-dimensional printing. acrylonitrile–butadiene–styrene (ABS) samples are divided into five groups, based on different degrees of cryogenic treatment. A hydraulic universal testing machine is used to test the samples’ tensile properties, percent elongation and bending strength, while each sample’s wear performance is tested by using a tribometer. In addition, the functional groups and the internal molecular chain in every sample are characterized by Fourier transform infrared spectroscopy. The experimental results show that cryogenic treatment is an effective technique for the enhancement of the mechanical properties of ABS, such as its tensile strength, bending strength, wear performance and crystallinity. Particularly, the mechanical properties of ABS are improved after cryogenic treatment at −130°C for 4 h. The tensile strength is improved by 6·31 MPa, 93% higher than that of unprocessed samples. The bending strength is improved b...

Napredak u istraživanju metoda priprave nanokompozita grafena za niskotemperaturne gorivne ćelije i litij-ionske baterije

Because of its unique two-dimensional structure, huge specific surface area, high electrical conductivity, and other excellent performances, graphene has shown great potential for application in catalysis, electronics, sensors, energy storage, and other areas. Especially, graphene nanocomposites have been found to be promising catalyst support for low-temperature fuel cells, and as anode nanomaterials for high reversible capacity and excellent rate capability for lithium-ion batteries, which has triggered a new round of research hotspot. Preparation methods of graphene nanocomposites mainly for low-temperature fuel cells are reviewed. Particularly, the research progress and principles of physical preparation methods (molecular beam epitaxy), chemical preparation methods (chemical reduction, electrochemical deposition and hydrothermal/solvothermal methods, etc.) and high-energy ball milling are summarized. Research outlook of graphene nanocomposites for low-temperature fuel cells are prospected.

Research Progress of Preparation Methods of Graphene Nanocomposites for Low-Temperature Fuel Cells and Lithium-Ion Batteries

Because of its unique two-dimensional structure, huge specific surface area, high electrical conductivity, and other excellent performances, graphene has shown great potential for application in catalysis, electronics, sensors, energy storage, and other areas. Especially, graphene nanocomposites have been found to be promising catalyst support for low-temperature fuel cells, and as anode nanomaterials for high reversible capacity and excellent rate capability for lithium-ion batteries, which has triggered a new round of research hotspot. Preparation methods of graphene nanocomposites mainly for low-temperature fuel cells are reviewed. Particularly, the research progress and principles of physical preparation methods (molecular beam epitaxy), chemical preparation methods (chemical reduction, electrochemical deposition and hydrothermal/solvothermal methods, etc.) and high-energy ball milling are summarized. Research outlook of graphene nanocomposites for low-temperature fuel cells are prospected.

Performances of Sulfonated Polyether Ether Ketone Composite Membranes for Fuel Cell Applications

A variety of modification approaches such as cross-linking and nano blending have been explored to prepare efficient membranes based on Sulfonated polyether ether ketone (SPEEK). The addition filler is also one of the most widely used approaches to modify the SPEEK. The crosslinked membranes were utilized as proton exchange membranes (PEM) for fuel cell application. The performances of these composite membranes were comparative researched in terms of water uptake, ion exchange capacity, proton conductivity, and methanol permeability.While the nanohybrid membranes display remarkably enhanced proton conduction property due to the incorporation of additional sites for proton transport and the formation of well-connected channels by bridging the hydrophilic domains in SPEEK matrix. The as-prepared nanohybrid membranes also show elevated thermal and mechanical stabilities as well as decreased methanol permeability.

Study of 1 # direct methanol fuel cells for commercial market applications

In order to reduce the costs and improve the performances, conceptual design was proposed for a novel direct methanol fuel cells (DMFCs), named “1#DMFCs”, whose outside size and shape were ascertained by common 1# batteries. All basic parameters were gained from experiment datum. Inside dimension and structure were determined by calculating, admeasuring and devising elaborately. Three-dimensional model was devised through Pro/E, planar diagrammatic drawing was created by the software also, and detail drawing was drew with CAD further. Tubular membrane electrode assembly (MEA) without the fluid fields bipolar plates was used in this conceptual design, which was made up of titanium mesh anode layer, anode catalyst layer, Nafion membrane layer, cathode catalyst layer, gas diffusion layer and titanium mesh cathode layer in turn. This 1#DMFCs had perfect structure, including a one-way valve, a plug screw, a self-locking collecting water part et al. The MEA working area of 1#DMFCs was increased effectively by using of two tubular MEA, which would enhance the performance of the 1#DMFCs consequently.

Design and Analysis Of composite material bipolar plate pressure injection molding based on Pro/ENGNEER

A bipolar plate is one of the key components of a proton exchange membrane fuel cell. Development of a suitable processing method for bipolar plate is scientically. Three kinds of processing methods of composite bipolar plate are compared, and it thinks moulded method is the least investment shaping method. According to the shape and structure of the bipolar plate, pressure injection molding was designed by using three-dimensional design