bluuebunny/crossref_metadata_2025 huggingface dataset:
The Precision Observation of Projection Model for Microgripper System Based on Stereo Light Microscope
Authors: Wang Yue Zong , Zhang Chen Chen , Ma Guo Dong , Yin Wen Jia
Published: April 2014

Micro stereovision technology has been widely used in the small scale micro objects which are not convenient observed for human eyes, through micromanipulation and other ways to do image reconstruction for the object surface and show them out in the computer, but during the operation, the precision problem of the position control system and the microgripper system relation to the precision of micro stereovision system. This paper built the camera projection model based on the micro stereovision system and have done lots of displacement experiments of the mobile platform and the gripper reconstruction experiments of microgripper system, through statistical analyzed these experiment data to show the accuracy of the microgripper system.
Design and Research of Dynamical Property Testing System for Nano and Micron Inertial Components
Authors: Zhang Li Yong
Published: April 2014

The accelerometer is a sensitive inertial component of the inertial navigation system, and its output signal is proportional to the transporters acceleration. In system design and test, the dynamic characteristic of the closed-loop system is an important parameter. At present, the use of wire vibration or angular vibration to provide an input signal cannot meet the amplitude and phase of system testing requirements, and the test cost is high. Therefore, the study of how the dynamic characteristics of electrical simulation test system to give a precise mathematical accelerometer model is an important part of the analysis of the inertial navigation system,which is an effective method to acquire the dynamic characteristics and can be extended to mini inertia instruments. In this paper, we use the system identification method to identify the model of the system. Modeling of the system identification method is to determine the mathematical model of the system by observing the relationship between system inputs and outputs. The content of system identification generally includes four parts which are experimental design, model structure identification, parameter estimation and model test. Circuit simulation test of dynamic character of accelerometer system and model identification method have been applied in practical application. This paper has tested the accuracy of developed system designed by different system identifications.
Research of a New Type Rectifier and Voltage-Multiplier Piezoelectric Energy Harvester Circuit
Authors: Lan Jin Hui , Xiao Shu Wei , Zhang Jian , Lin Tong , Yang Jun
Published: April 2014

Traditional rectifier circuit can convert AC to DC, but some disadvantages cant be avoided, such as small output current, high power consumption, low conversion efficiency. This paper designs a new type of rectifier voltage-multiplier circuit named MR_MOS circuit. It uses a low let-through resistance MOS tube to replace the conventional rectifier diode, and adds the voltage-multiplying factor to the synchronous input port. Therefore, it can improve the rectifier effect and increase the output voltage. By the simulation result of Synopsys Saber Platform, it shows that the new type circuit can implement the rectification and voltage-multiplying by the simulating output pulse voltage of nanofiber made in Deakin University as the source of excitation. It can provide the basic theoretical of the piezoelectric energy harvester (PEH) development, and has certain reference significance to the development of piezoelectricity technology.
Design and Simulation of a Parylene-Based Three-Dimensional Cuff Electrode for Peripheral Nerve Stimulation
Authors: Xiong Wen Jie , Yu Huai Qiang , Li Zhi Hong
Published: April 2014

In this paper, a parylene-based three-dimensional cuff electrode for peripheral nerve stimulation was proposed and simulated. The three-dimensional (3D) finite element model was built for simulation study of the electrode. The simulation results show this design has higher power efficiency than conventional planar electrode and it can realize selective stimulation of different fascicles in the target nerve. Moreover, the tripolar configuration has better control of the stimulation electric field than monopolar.
Study on the Influence of N-Doping to the In Situ Growth TiO2 Film Photocatalytic Character
Authors: Yu Zhong Chen , Wang Song , Wang Xin , Niu Yuan Lin , Li Zhuan
Published: April 2014

Thin TiO2 films in-situ growth on titanium alloy substrate were prepared in 0.05 mol/L H2SO4 electrolyte using the micro plasma oxidation method. The photocatalytic properties of the prepared thin TiO2 films were invested using Rhodamine B solution as a target pollutant. In order to improve the photocatalytic properties of the obtained TiO2 films, different content NH3·H2O was added into the H2SO4 electrolyte and obtained the N-doped TiO2 films photocatalyst. The influence of the doping ions on the crystal phase composition and microstructure of the TiO2 films were investigated by scanning electron microscopy (SEM) and X ray photoelectron spectroscopy (XPS). The results show that TiO2 films have uniformly grown closely on the surface of titanium substrate with pore size of 100-200 μm. The degradation efficiency of the TiO2 thin film prepared in H2SO4 + NH3·H2O is higher than that prepared with H2SO4, the degradation efficiency can reach 99% after 75 min, which increase about 10% than that of the H2SO4 eletrolyte.
Reliability Factors Analysis of MEMS Safety and Arming System
Authors: Zhang Hui , Wang Ying , Lou Wen Zhong , Liu Fang Yi , Wang Fu Fu
Published: April 2014

According to the status of the lack of reliability data for MEMS fuze, this paper mainly studied the reliability factors of MEMS Safety and Arming System by using Dynamic simulation method. Through simulation analysis, the mainly reliability factors, weakness and potential failure modes of MEMS Safety and Arming System can be obtained, which can provide theory reference and data support for the design and application of the MEMS Safety and Arming System.
Synthesis and Characterization of Highly Dispersed and Homogeneous Nano Zinc Oxide Rods
Authors: Li Yu Xia , Ren Zhen , Guo Jian Ping , Xi Yun Long
Published: April 2014

Highly monodispersed ZnO nanorods have been synthesized by the hydrothermal approach with polyacrylamide (PAM) as the template and zinc acetate as the zinc source. Most of these synthesized ZnO rods have diameters of 30 nm~200 nm and lengths of 80 nm~15 μm. The structural characterization of ZnO nanorods was carried out by XRD, TG, FTIR, TEM and SEM. nanoZnO rods can be prepared merely by one step reaction using little template. It indicated that this method can be applied to the commercialization of rod-like ZnO preparation technology.
Characterization of Ag-TiO2 Electronic Structures and Nanotubes Based on First-Principles Calculation
Authors: Li Jing Ling , Cao Xiao Xia , Wu Bo , Yu Hua Liang , Gan Yong Jiang
Published: April 2014

In this manuscript, we report the simulation of electronic structures of TiO2 doped with Ag using first-principles calculation, based on the density functional theory (DFT) The mechanism to improve the visible-light photocatalytic activity for TiO2 doped with Ag. EF was displaced into the valence band (VB), narrowing the band gap. An independent energy band was also introduced above the VB and an energy band with the width of 0.9 eV is introduced under the conduction band (CB), also resulting in the narrowing of the band gap. New VB and CB were formed by three orbitals O-2p, Ti-3d and Ag-4d. Composite TiO2 nanotubes with Ag-doping were synthesized using the alkaline fusion and hydrothermal method under ambient atmosphere. XRD results indicated composite Ag-TiO2 nanotubes ranging from the single anatase phase to the anatase and rutile mixed phase. XPS showed an increase in the surface acidity and photo catalytic activity of TiO2 nanotubes due to the presence of OH radicals. Furthermore Ag-doping also facilitated the separation of photo-holes and photo-electrons and enhanced the optical properties.
Research on the Preparation of Antimony Nanoparticles by Mechanical Ball Milling
Authors: Xu Jian Lin , Zhang Liang , Guo Qiang , Zhou Sheng Gang , Feng Chong
Published: April 2014

Taking antimony powder with 75μm of average particle size as raw material, the antimony nanoparticles were synthesized by mechanical ball milling. Crystalline structure, morphology and particle size of the antimony nanoparticles were characterized by XRD, TEM and FT-IR. The effect of milling mediums and ball milling speed on results antimony nanoparticles were studied using dry grinding and wet grinding methods. The results show that the antimony nanoparticles can be prepared successfully by wet process of ball milling. When the ball milling speed is 150 r/min and the milling mediums is a composites of distilled water and OP-10, the best antimony nanoparticles were prepared, which is high dispersibility and the average particle size is 10 nm.
Fabrication and Phase-Transition Characteristic Investigation of Nanocrystalline VO2 Thin Film
Authors: Chen Xi Qu , Hu Xi Zheng , Lv Qiang
Published: April 2014

In this paper, nanocrystalline VO2 thin film is fabricated by a kind method of two steps and its phase transition characteristics are investigated. The two-step method contains low-temperature reactive ion sputtering and post-annealing, and its process parameters determine the phase transition properties of fabricated VO2 thin film. With optimized process parameters, VO2 thin film with nanocrystalline structure can be successfully fabricated and has excellent phase transition performance for smart glass and optical switch.
Synthesis of Nanosized NaY Molecular Sieve under Dynamic Hydrothermal Crystallization
Authors: Chen Ying , Liu Peng , Yu Zhi Wu , Tan Juan
Published: April 2014

Nanosized NaY molecular sieves with high crystallinity was synthesized using sodium silicate solution (industrial water glass) without the presence of additive via dynamic hydrothermal method. The influences of aging time of the seed-gel, the temperature and route of gelation, and the alkalinity of the feed-stock gel on the grain size, relative crystallinity and framework SiO2/Al2O3 ratios of NaY nanoparticles were investigated by XRD(X-ray diffraction, XRD), SEM(Scanning electron microscope, SEM) and TEM(Transmission electron microscope, TEM). The results shown that the grain size could be effectively controlled by adding seed-gel of aging at 20°C for 4 days, and adopting the gelation route of putting sodium silicate solution into NaAlO2 and NaOH mixed solution. The grain size and framework SiO2/Al2O3 ratios decreased with reducing the alkalinity of synthetic system. The nanoNaY products with the grain size at a range of 82-105 nm and the framework SiO2/Al2O3 ratios at 3.9-4.0 could be synthesized by optimizing the synthesis conditions.
Preparation of Nano Silicon Dioxide with Sol-Gel Method
Authors: Fang Lian Min , Liu Peng , Chen Ying , Yu Zhi Wu
Published: April 2014

The influences of temperature, compounds dosages and water on the size of nanosilica prepared by tetraethyl orthosilicate were discussed, and the transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were employed to investigate the characteristics of the nanosilica synthesized by the sol-gel method. Moreover, the silane coupling agent was also used to modify the surface characteristic of the nanosilica. Results showed that the influences of temperature, compounds dosages and water on the size of nanosilica had a significant impact. In fact, the optimal synthesis temperature was 45 degrees centigrade, and the stirring time was 2 hours. In this case, the nanosilica can be prepared with the grain size of 100 nm and the narrow particle size distribution. By FTIR analyzing, it can be seen that the combination of the nanosilica and the silane coupling agent was chemical reaction. In addition, the tests showed that the adsorption process finished in 40 minutes.
Photoelectric Properties of Metallic Mesh Based on Flexographic Printing
Authors: Li Xiu , Liu Wei , Xu Yan Fang , Wang Yu , Ran Jun , Li Lu Hai
Published: April 2014

This paper introduces the principle and manufacture process of a film-taped metallic mesh, and the influence of the parameters of metallic mesh film on optical and electromagnetic features has also been analyzed. By using the flexographic printing technology, the metal mesh film with the line widthes of 15, 203040μm and the period of 300μm on PET substrates have been made, and the maximal electromagnetic shield effectiveness is more than 15dB. The results indicate that the optical and electrical performance of the metallic mesh film is inconsistent, and it is better to select a thinner line width and smaller period to obtain optimal shielding effectiveness.
Switchable Wettability of Silicon Micro-Nano Structures Surface Produced by Femtosecond Laser
Authors: Wang X.Q. , Ding Jian Ning , Yuan Ning Yi , Wang S.Y. , Qiu J.H. , Kan B. , Guo X.B. , Zhu Y.Y.
Published: April 2014

Silicon micro-nanostructures were directly produced by femtosecond laser in air. By varying the laser power, we can tune the surface morphology, the wetting property. As-prepared silicon micro-nanostructures show superhydrophilicity, but with removal of native SiOx, superhydrophobicity is observed without surface modification. And a reversible switch between superhydrophilicity and superhydrophobicity can be realized by immersing samples in hydrofluoric acid and hydrogen peroxide, respectively, for many times.
Theoretical and Experimental Research of CO2 Absorption Enhancement by Carbon Nano-Tube
Authors: Lu Su Min , Xing Min , Li Yong Dan , Song Jing
Published: April 2014

The enhancement characteristics of carbon nanotubes (CNTs) on CO2 absorption were investigated experimentally a stirred thermostatic reactor. A comparison of CNTs with micro active carbon was made. From the experimental results, significant enhancement of CO2 absorption was obtained by both CNTs and micro active carbon, however, different change trends with stirring speed for the two solid particles was observed. With increasing stirring speed, the enhancement factor was decreased in AcC suspensions, whereas in CNT slurries it is increased. The experimental phenomena demonstrated a difference in enhancement mechanism for different size particles. For nanoparticles, besides the grazing effect, the micro-convection caused by Brownian motion should be also taken into account. The micro-convection strengthens the interaction of the concentration field around the particles and thus increases the diffusion rate of the solute. In addition, the agglomeration of the nanoparticle was also an important influencing factor. Due to the agglomeration of the particle, the enhancement factor for CNTs increases initially with increasing stirring speed. A three-dimensional microcosmic mass transfer model was developed to explain the experimental phenomena. Based on the model, the interaction of the flow field around the particles was analyzed.
Design and Fabrication of a Micro Spring with Steel Structures for the Microtensile Testing of Thin Films
Authors: Miao Bin , Wei Xiao Wei , Wu Dong Min , Li Jia Dong
Published: April 2014

A novel micro spring with steel structures is described here. It can be fit into a specially designed microtensile apparatus, which is capable of carrying out a series of tests on micron scale freestanding thin films. This method is suitable for thin metal films or polymer layers with large strain and can be applied to samples with different thicknesses. The novel fabrication method uses the conventional lithography and electrochemical metal etching techniques. A single photomask is used to define the whole structure, resulting in a simple and inexpensive fabrication process. The method proposed here is promising for the low cost fabrication of micro spring based on steel. A micro spring of 100μm wide, 100μm thick, with 200μm diametric of the semicircle and 6 turns was prepared by this method; the elasticity of the spring is 147.3N / m. A gold wire was measured by this micro spring. The young's modulus and ultimate tensile strength of the gold wire were 30Gpa and 120Mpa, respectively.
Preparation and Antibacterial Bioactivity of Ti-Base Titania Nanotube Arrays
Authors: Tian Tian
Published: April 2014

A vertically aligned bioactivity titania nanotube arrays was fabricated on the surface of titanium substrate by anodization. The nanotubes were then treated with optical deposition of silver to make them antibacterial, and to inhibition growth of bacterial in the antibacterial test in vitro. It is shown that the present of silver particle inhibition the growth staphylococcus aureus. Such bioactivity titania nanotube arrays and associated hollow tube structure can be useful as a well-adhered antibacterial bioactive surface layer on titanium implant metals for orthopaedic and dental implants.
Fenton Degradation of Methylene Blue by CuFeS2 Ultrafine Powders
Authors: Liang Da Xin , Li Jian , Li Lu , Pang Guang Sheng
Published: April 2014

Fenton reagent was made by CuFeS2 ultrafine powders with peroxide, and this Fenton reagent can degrade methylene blue solution with 10 mg/L concentration within 1 min. UV-vis spectra were used to investigate this Fenton reagent's degradation activity of methylene blue.
Study and Fabrication of Filter Film in Tactical Optical Fiber Communication System
Authors: Tang Hao Long , Liu Guo Jun , Fu Xiu Hua
Published: April 2014

The development of optical fiber transmission technology provides a broad application prospect for the communication of real-time battlefield information. The information could be communicated between the front and headquarters through the cable by using tactical optical fiber communication system, which ensures the missions of military intelligence communicated and tactical real-time arrangement are completed successfully. According to the requirements of multiplexer for military tactical optical fiber communication system, the filters with low-loss have been developed. Filters are prepared by the depositing method of dual ion beam sputtering, Nb2O5 and SiO2 have been chosen as deposition materials, and the filter film is designed and optimized with the help of TFCalc software. In order to broaden the shortwave cutoff region of the filter, the long-wave pass film have been added behind the initial film, and the thickness of the matching layers have been optimized, which based on the concept of equivalent refractive index, the insertion loss of the pass-band of the filter has been reduced. The optical extreme value method and average time method have been used to control layers thickness, and the problem of the layers thickness accuracy controlling have been solved by using the method of real-time calibration of the deposition rate and the repeatability of parameters accurately control. The transmission spectrum of the filter has been tested, which demonstration that the center wavelength of the filter is 1511.2nm, the width of the filters pass band is 17.1nm and 23.5nm in the region of-0.5dB and-35dB respectively, the worst insertion loss within pass band region is-0.1dB, the ripple of the pass band is 0.06dB. The results show that the preparation of the filter meets the using requirements of military tactical fiber optic communication system well.
Self-Assembly of a Superhydrophobic ZnO Nanorod Arrays Film on Wood Surface Using a Hydrothermal Method
Authors: Sun Qing Feng , Lu Yun , Li Jian , Cao Jun
Published: April 2014

To prohibit wood hygroscopicity, changing naturally hydrophilic wood surface into hydrophobic surface is essential. To achieve this goal, one possible approach is to coat nanostructured metal oxides on wood surface. In this study, wood surface coated by ZnO nanorod arrsys (ZNAs) was successfully fabricated using a hydrothermal method with subsequent modification by a thin layer of n-dodecyltrimethoxysilane (DTMS). SEM images showed uniformly large-scale ZNAs were grown onto the wood surface. XRD patterns confirmed that the ZNAs were the hexagonal wurtzite phase. The wettability of the ZNAs modified wood sample was evaluated by water contact angle (WCA) measurements. The ZNAs modified wood was found to exhibit superhydrophobicity with a WCA of about 156° and a sliding angle of around 2°, which could resulted from the proper surface roughness and lower surface energy. These results demonstrated that hydrothermal method was a feasible method to create superhydrophobic wood.
Large-Area Self-Assembled Monolayer of Silica Microspheres by Convective Assembly
Authors: Wang Yue Hui
Published: April 2014

We reported here a convective assembly process for the formation of large-area self-assembled monolayers of silica microspheres on silicon and glass substrates. Uniformly coated monolayers of silica spheres were achieved on silicon wafers with and without coated SiN2 of 3 inch of diameter and large glass substrate of 6 × 6 in2 in size. The coating of large-area uniform monolayers of silica microspheres was characterized with scanning electron microscopy and optical microscopy. The mechanism of the convective assembly has been explained by the convective flux that is generated by capillary immersion force caused from the solution evaporation and hydrodynamic drag force. The patterns of silica microspheres were transferred to the silicon substrates using a deep reactive ion etching technique. It is found that textured silicon reduced the reflectance of silicon substrate from 52.2% to 33.2% around 400 nm and from 33.9% to 19.5% around 1,100 nm. The rapid self-assembled monolayer with silica microspheres provided a glimpse at the wide range of coating and photonic device applications where convective assembly can be used.
Glass Frit as a Hermetic Joining Material for Bonding among Three Wafers with Metallic Film Feed-Through
Authors: Zhao Cong , Wang Jian , Zhang Shi Ming , Zou Jiang Bo
Published: April 2014

This paper reports a sealing process for reliable hermetic wafer-scale packaging among three wafers forming sandwich structure by glass frit. The process could be applied to Si, quartz crystal, SiC wafers and so on. The device wafer is bonded to the capping wafer in the first step and to another capping wafer forming vacuum-cavities in the second step. Experimental results indicate that the average bonding strength of packaging structure reached as high as 0.85kg/mm2 fulfilling MIL-STD-833E standard. The average leakage rate fits the standard of GJB-548A.This paper also realizes glass frit hermetic bonding in the case of Au/Cr and Pt/Ti film feed-through deposited on the device wafer.Experimental results indicate that Pt/Ti film feed-through hold up to bonding temperature cycling and avoid dissolution and adherence reduction compared with Au/Cr film feed-through
Research on Air-Media Mixed Substrate Technology of GaAs Based Millimeter Wave Antenna
Authors: Jiang Guo Qing , Jia Shi Xing , Hou Fang , Zhu Jian
Published: April 2014

Becoming another key technology for system integration, GaAs based millimeter wave antenna is fabricated by MEMS technology, with high permittivity dielectric substrates. To obtain good performance, it is necessary to achieve the equivalent of low dielectric constant of the local area below microstrip patch antenna. The article describes deep etching fabrication and multiple etching with thick photoresist masking to creat air cavity under the microstrip patch which usually has the height from 70% to 80% of the original media substrate, thus it forms the air-mixed media substrate. Especially for precision control of the substrate thickness, use back thinning and high-precision polishing processes. At last realize back cavity depth of 227μm in the GaAs substrate and complete the process of Ka band MEMS patch antenna. The measurement results: the center frequency is 37.9 GHz, bandwidth is 4.4%, radiation efficiency above 50%.
A Novel Nanoparticles Activation Technique for Electroless Plating on ABS Plastic
Authors: Ma Hong Fang , Ma Fang , Sun Hua , Wang Xiaor Rui , Jiang Rong Yan , Zhang Chang Cun
Published: April 2014

This paper reports a novel and facile activation process for electroless copper plating on Acrylonitrile Butadiene Styrene (ABS) plastic substrate using gold nanoparticles as catalyst. Gold nanoparticles were prepared by chemical reduction method and characterized by UVvisible adsorption spectrum and transmission electron microscope (TEM). The gold nanoparticles were sphere-like with a size of less than 50 nm. Gold nanoparticles were adsorbed on ABS surface and acted as nucleation centers in activating process of the electroless copper plating. The uniform and dense film was obtained at the optimal technological parameters which were achieved by the orthogonal experiment. The scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) were used to detect the morphology, structure and elemental composition of the coating, respectively. The results indicated that copper coating contained only Cu (0) without any other elements.
Experimental Study on Dispersion Stability of Rutile TiO2 Nano-Particles Suspension of Ammonia-Water Solution
Authors: Wu Yun Long , Du Kai , Yang Liu , Bao Shuai Yang , E Wen Ji
Published: April 2014

In order to apply nanofluids to ammonia-water absorption refrigeration, several groups of nanofluids mixing with rutile TiO2(r-TiO2) and ammonia-water were perpared by an optimizing method. Observation tests were carried out to investigate the effects of the kind and mass fraction of dispersant, mass fraction of ammonia-water basefluid and durations of supersonic vibration on the dispersion stability of nanofluids. The results show that, all three factors have influences on the dispersion. The optimal dispersing condition of 0.1wt% r-TiO2 nanofluids was 0.1% of PAA in 25% ammonia water basefluid with 10 minutes of ultrasonic vibration.
Improving the Current Stability through the Bubbles-Free Microfluidic Electro-Spray Ionizing Chip
Authors: Qian Xiang , Liu Lang , Yu Quan , Jing Gang , Wang Xiao Hao
Published: April 2014

The bubbles in the microfluidic based electro-spray ionizing chips seriously affect the performance of the system. This paper presents a bubble capture method to stabilize the current of the microfluidic based electro-spray ionizing sources. A bubble capture structure was introduced to collect the bubbles. A normal close clamp valve assured a suitable pressure in the bubble capture structure that no liquid in the microfluidic channel can enter; when the bubble capture structure was filled with gas bubbles, the clamp valve was opened to release the bubble and balance the pressure. The results indicated that the current fluctuation, which reflects the stability of the electro-spray ionizing devices, was below 1.8% during the stable cone-jet electro-spray stage (2000V~4500V) for the proposed system, which was a notable improvement comparing with normal microfluidic-based electro-spray ionizing chip without the bubble capture structure.
Organic Solvent Fumigation Bonding for Multi-Layer Poly(methyl Methacrylate) Microfluidic Device
Authors: Zhang He , Liu Xiao Wei , Tian Li , Han Xiao Wei , Liu Yao
Published: April 2014

In this paper, a novel bonding method for microfluidic devices was presented. The organic solvent fumigation bonding method can be used to produce multi-layer PMMA microfluidic devices under the condition of room temperature and low pressure. During the bonding, we choose chloroform as bonding solvents, the polyimide tape was used to protect no-need-bonding side of the cover sheet and the sealant silicone adhesive was used to protect the microstructure in the bonding side. The substrate was fumigated for 5minutes in the saturated steam conditions, then remove the polyimide tape as well as the sealant silicone adhesive. Assemble the fumigation cover sheet to the substrate with microchannel by using fixtures, soon after put the fixture and the substrates into the oven, dried at 50 °C for 10 minutes. Finally, remove the fixture, the bonding complete. Because of the bonding was accomplished under conditions of low temperature and pressure, the deformation of microchannel is very small. When the method was used for multilayer chip bonding, it also achieved good results.
Numerical Analysis of the Liquid Crystalline Backflow-Driven Effect under a Continuous Square Wave Electric Field
Authors: Liu Chun Bo , Wang An Biao
Published: April 2014

In order to broaden the application range of liquid crystals, a new microfluidic drive and control method is proposed. Through a simulation model construction that links the plate motion and the liquid crystal backflow, we can study the coupling of the internal alignment and velocity fields of the liquid crystal in the model. On applying a continuous square wave electric field, the upper plate of the cell can be driven to move continuously, and the moving state can be related to the structure of the cell. When the gap between the two plates was 50 μm, the range of the change of tilt angle at the center of the cell was 6090°, and the induced backflow velocity profile was an S-shape. When the gap was 110 μm, because of the influence of the kickback effect, the range changed to 90100°, and the velocity profile was a double S-shape.
Preparation and Microstructure of Layered Hydroxyapatite Nanorods on Bioceramic Coatings Using Plasma Electrolytic Oxidation Technique
Authors: Li Ying , Wang Qin , Fang Jian Hong , Gao Qing , Lin Ming , Han Ji Qin , Li Feng , Xu Xin
Published: April 2014

Plasma electrolytic oxidation (PEO) has been one of the most applicable methods to deposit bioceramic coating on an implant and can provide the possibility for incorporating Ca and P ions. In this study, the titanium substrates were oxidized by optimized electric parameters for 5, 10, 15 and 20 mins respectively during PEO process, to analyze the effect of varied oxidation intensity on the microstructure, phase and element composition of the treated coatings. The results show that the PEO coating of 15 min exhibited excellent advantages of creating favorable microstructure, phase and element composition, and could promote the formation of nanoHA on the treated coating, as a result of some HA nanorods deposited on the surface after 7 days immersion in SBF. The PEO technique proved to be another choice to enhance the bioactivity of titanium and the coating could facilitate the precipitation of nanoHA to functionalize the biomedical materials.
Study on Fabrication Process of SU8 Photoresist Microstructures and Evaluation of Stress Gradient
Authors: Rong Hua , Wei Jian , Chen Xi
Published: April 2014

A fabrication process to manufacture SU8 photoresist microstructures is presented in which BP212 positive photoresist was used as sacrifice layer and SU8 was used as structure layer. No crack has been observed in the obtained microstructures. The relation between PEB temperature and stress gradient in SU8 film has been studied by measuring radii of released SU8 cantilevers made at different PEB temperatures.
Two Benches PDMS Free Flow Electrophoresis Chip
Authors: Wang Wei , Tian Li , Han Xiao Wei , Zhao Lin , Ye Guo Hua , Zhang Hai Feng , Liu Xiao Wei
Published: April 2014

This paper puts forward a kind of two benches structure of the glass-PDMS free flow electrophoresis chip. We use die casting method to produce microstructure, and use PDMS as its structure layer. The mold is made in tape-PMMA by micro cementing technology. During the progress of PDMS curing, gold wires are directly integrated in the electrode groove to form the chips electrodes. PDMS and glass are sealed in natural bonding method. Chips glass surface of separation chamber realizes the modification through sticking polyimide tape. Visual technology is conducted for chip electrophoresis separation. The sample is the mixture of methyl green and Rhodamine B. The separation effect of methyl green and Rhodamine B is obvious when the electric field is 31 V/cm. the "two benches" between the electrode groove and the separation chamber block the electrolytic bubbles into the separation chamber. When the separation chamber height is 70 μm and the electric field is 50 V/cm, the air bubbles can be glidingly discharged from electrode groove. The samples steady separation time is more than 2 hours, and this free flow electrophoresis chip realizes continuous work.
The Enhanced Raman Scattering from Ag Nanoball/ZnO Hollow Nanosphere Arrays Fabricated by Laser-Induced Annealing
Authors: Zang Ya Shu , Yin Jun , Li Jing , Kang Jun Yong
Published: April 2014

In this work, a facile method was presented to produce Ag nanoball (NB)/ZnO hollow nanosphere (HNS) hybrid structure. Large scale, two-dimensional (2D) ZnO HNS arrays were fabricated on sapphire substrates using the polystyrene (PS) nanospheres as the template. Ag film were deposited on ZnO HNS arrays by radio frequency (RF) magnetron sputtering and then aggregated into Ag NBs on the top of ZnO HNS by the laser irradiation treatment. The size and distribution of Ag NB arrays were controlled by employing different ZnO HNS supporting structure templates. The scanning electron microscopy (SEM) was applied to visually study the evolution process of Ag NB/ZnO NHS arrays. X-ray diffraction (XRD) was carried out to characterize crystal structures of the samples. Obvious surface enhanced Raman (SERS) signals were observed from the Ag NB/ZnO NHS nanocomposite structure compared with that in the ZnO HNS structure by using the R6G as the testing agent. Theoretical simulation results demonstrate that the Raman enhancement originates from the significant enhanced local electromagnetic field induced by the surface plasmon resonance (SPR) of Ag NBs.
Study on Parameters of MEMS Planar Zigzag Slot for Fuze
Authors: Zhou Zhi Jian , Nie Wei Rong , Wang Xiao Feng , Xi Zhan Wen
Published: April 2014

This paper has proposed a MEMS planar zigzag slot for fuze to discriminate between drop impact acceleration and smooth start acceleration. It can fulfill the requirements that fuze power should be activated reliably in smooth start environment and kept off in service handling environment. The planar zigzag slot is used in medium and large caliber ammunition. At first, a structure consists of a spring, a mass with an anchor, a fixed zigzag slot and two baffles has been proposed. Then, the working principle of the structure and motion of anchor after colliding to zigzag slot has been analyzed. At last, key parameters of the structure on the performance of acceleration recognition is studied by dynamic simulation.
The Study of SiC Thin Films Produced by Magnetron Sputtering
Authors: Lai Lei , Wang Xiao Jia , Hao Jun Jie
Published: April 2014

In this paper, SiC films were deposited on the surface of 316L stainless steel by magnetron sputtering with sintering SiC target to improve its wear resistance. The structure and morphologies of the SiC films were characterized by XRD and SEM. The impacts of sputtering way, deposition time, and substrate temperature on the deposition rate and mechanical properties of SiC films were further investigated by the performance parameters of hardness, elastic modulus, friction and wear properties, coating adhesion, etc. The results show that coating adhesion is higher when the films are deposited by mid-frequency magnetron sputtering than that of which by direct current sputtering; Hardness and elastic modulus of the films increased gradually with the deposition time changing from 1 to 5h or the substrate temperature changing from room temperature to 200°C; However, the friction coefficient initially decreases, but turns to increase with the deposition time prolonging or the substrate temperature rising. The wear resistance of the films is the best when deposition time is 2h and substrate temperature is 100°C.
Fabrication and Formation Mechanism of Electrospun Spatially Defined Fibrous Patterning Structures on Conductive and Insulating Substrates
Authors: Liu Shu Liang , Sun Guang Hui , Huang Yuan Yuan , Sun Bin , Zhang Hong Di , Long Yun Ze
Published: April 2014

Besides the conductive patterning substrate, spatially well-defined microfibrous architectures can also be electrospun by using an insulating topographically structured collector (e.g.a nylon fabric). In both cases, it is proposed that the formation of the electrospun microfibrous patterns can be ascribed to the re-distribution of static electric field whenever collectors with different topography are introduced. Moreover, a series of simulation of the static electric field for various collectors (e.g.flat Al foil, conductive and insulating patterned substrates) have been systematically made to illustrate the formation mechanism, respectively. Our results are considered to warrant further scientific understanding on the formation of electrospun microfibrous patterning constructs, and helpful for easy generation of spatially defined architectures which have applications in a variety of areas such as tissue engineering, cell adhesion, proliferation and migration,etc.
Design and Analysis of a Novel Locking Mechanism of MEMS Safety and Arming Device
Authors: Wang Fu Fu , Lou Wen Zhong , Wang Ying , Liu Fang Yi , Lu Jun , Wu Jian
Published: April 2014

In this paper, a novel locking mechanism of MEMS S&A device has been proposed. Through establishing the mathematical model of the motion for the slider and simulating the physical model by the non-linear dynamic mechanics, appropriate novel locking mechanism is designed to meet two items, one item is the slider can slide to the bottom under the launch overload conditions; the other item is the slider cant be pulled back after the launch overload conditions. Through the experiment, the feasibility of the above research is confirmed.
Surface Modification of Nano-Titanium and its Effect on the Antibacterial Property of Waterborne Wood Coating
Authors: Qian Lei , Long Ling , Xu Jian Feng
Published: April 2014

In the paper, the surface modification of nanotitanium and its effect on the antibacterial properties of waterborne wood coating were studied. The effect of the type and amount of surfactant (system) and the ultrasonic treatment time on the property of nanotitanium and the effect of the dosage and adding method of nanoslurry on the properties of water-based wood coating were both investigated. The nanotitanium slurry made in the optimum conditions was also characterized. The results showed that nanotitanium slurry with excellent performance was obtained when 0.5wt% polyoxyethylene octylphenol ether and 3wt% sodium polyacrylate were used and ultrasonic treated 5h. It also showed that the waterborne wood coating with excellent drying performance and antibacterial property was got when 1.5wt % nanoslurry was mixed to water-based emulsion to hybrid. Under the conditions, the antibacterial rate against Escherichia coil and Staphlococcus aureus reaches to 95%.
Control System of an Electromagnetic Vibrating Ring Gyroscope
Authors: Liu Ji Li , Chen De Yong , Wang Jun Bo
Published: April 2014

Presented is a control system that is designed for an electromagnetic vibrating ring gyroscope. Three functions are realized in this control system. First, fixed amplitude of the drive-mode is guaranteed by using a variable gain control (VGC). Test result shows that the stability of the drive-mode amplitude is about 0.4% in the range of-40°C~80°C. Second, suitable drive-frequency is set up. And experimental result indicates that the suitable drive-frequency should be set between the drive-and sense-mode resonance frequencies, which results in a superior sensitivity. Third, regulation module is employed to further improve the performance.
A Novel Passive Wireless Humidity Sensor Based on a Dual-Metal Inductor
Authors: Li Guo , Huang Jian Qiu , Zhang Cong , Wang Li Feng , Huang Qing An
Published: April 2014

This paper describes a wireless, passive humidity sensor, based upon an inductor-capacitor circuit. An inductor with a dual-metal structure is employed to reduce the size of the chip and decrease the complexity of the process. This paper analyzes the shortcomings of conventional sensors and gives a novel structure to overcome these disadvantages, and also use ADS to simulate and verify the feasibility of the new structure. Finally this paper presents a detail fabrication process of this novel sensor. According to the wireless applications, the LC resonant frequency of the LC circuit was designed at 30 ~ 150 and 350~450MHz.
Structure Refinement of Medium Carbon Steel and Deformation Properties Respond
Authors: Zrník Jozef , Dobatkin Sergey , Raab George
Published: April 2014

The work presents the results on grains refinement of steel containing 0,45 wt pct carbon resulted from severe plastic deformation (SPD). Different steel structures from prior solutioning and/or thermomechanical treatment were prepared for deformation experimental. A coarse grain ferrite-pearlite structure was achieved applying solutioning. By application of thermomechanical (TM) controlled forging process, performing multistep open die forging, the refined ferrite-pearlite mixture was prepared. Final structure refinement of steel, having different initial structure, was then accomplished applying warm Equal Channel Angular Pressing (ECAP) at 400°C. Employment of this processing route resulted in extensive deformation of ferrite grains and cementite lamellae fragmentation. Applying the highest shear stress (εef - 4) the mixed structure of subgrains and ultrafine grains was present within the ferrite phase. In pearlite grains, modification of cementite lamellae due to shearing, bending, twisting and breaking was found efficient. The coarse cementite lamellae spheroidization was more efficient in prior TM treated steel. The tensile deformation records confirmed strength increase and diversity in strain hardening behaviour.
Shape Evolution of Cementite during Accelerated Carbide Spheroidisation
Authors: Dlouhý Jaromir , Hauserova Daniela , Novy Zbysek
Published: April 2014

Pearlite spheroidisation of 100CrMn6 steel was investigated. This process is well known and studied during conventional soft annealing. Presented paper describes cementite lamellae fragmentation during accelerated carbide spheroidisation. Mechanism of cementite lamellae fragmentation during conventional soft annealing depends on carbon and iron diffusion in ferrite-cementite system. On the other hand, accelerated carbide spheroidisation relies on partial pearlite austenitization and backward austenite decomposition. Aim of presented experiments was to examine shape evolution of cementite particles during transition from lamellar to globular form.
Pearlite spheroidisation is normally quantified by image analysis of 2D metallographic section. Conventional metallographic observation was used for globular-lamellar particle ratio estimation. However, whole lamellae observation is necessary for spheroidisation process revelation. Ferrite matrix deep etching and cementite separation was performed to study morphological aspects of acceolerated carbide spheroidisation.
Microstructure Development of Bearing Steel during Accelerated Carbide Spheroidisation
Authors: Hauserova Daniela , Dlouhý Jaromir , Novy Zbysek
Published: April 2014

Carbide spheroidisation is a significant metallurgical process, which contributes to profound changes in microstructure and mechanical properties. Carbide spheroidising occurs through diffusion, which is a long-term and energy-demanding process. The holding times, sometimes up to tens of hours make soft annealing one of the most expensive heat treatment processes. The process was newly designed at the company COMTES FHT shortens carbide spheroidising several times and therefore delivers considerable time and cost savings. The heat treatment was performed using induction heating. The purpose of this annealing process is to obtain globular carbides uniformly distributed in the matrix and to achieve overall softening. The present paper explores the effect of the newly-designed thermal schedules on the cementite lamellae fragmentation, on the decrease in hardness in bearing steel grade 100CrMnSi6-4 and on processing times.
Microstructure and Mechanical Properties of Steel Grade 14MoV6-3
Authors: Domovcová Lucia , Beraxa Pavol , Mojžiš Milan , Weiss Michal , Fujda Martin , Parilák Ľudovít
Published: April 2014

Steel grade 14MoV6-3 is a low-carbon microalloyed steel with addition of chromium and molybdenum. This medium-strength steel exhibits a ferritic-bainitic microstructure after the heat treatment. This grade is designed mainly for power industry applications, withstanding operating temperatures up to 580 °C; in Železiarne Podbrezová, this particular grade is used for production of hot rolled seamless boiler tubes. In this paper we present the basic chemical concept of 14MoV6-3 steel along with its mechanical properties after the heat treatment. Further, analysis of the final microstructure, carbide phases and precipitation of vanadium is being presented as well. For this purpose, the yield stress theory has been proposed along with predictive nomograms for selected ferritic-bainitic phases. According to the results of DTA analyses, necessary conditions for heat treatment after rolling have been proposed. Finally, CCT diagrams for required ferritic-bainitic structure are presented as well.
Effect of Sample Mount on Active Screen Plasma Duplex Processing
Authors: Nishimoto Akio , Nakazawa Kunishige
Published: April 2014

Nitriding steel sample SACM 645 was nitrided by active screen plasma nitriding using a titanium double screen to form simultaneously TiN coatings/nitrogen-diffusion layer on the sample surface. The sample was placed on the sample mount of the various materials (SACM 645, Cu, Ti and SiO2-Al2O3). The sample with the mount was placed on the sample stage in a cathodic potential. A titanium double screen was placed on the cathodic stage around the mount. Active screen plasma duplex processing were performed in 75% N2 + 25% H2 atmosphere for 18 ks at 823 K under 100 Pa. In each sample, the hardness of the sample surface was high and beneath compound layer, the hardness decreased rapidly with the distance from the surface, following a flattening of the profile. Wear loss of each duplex-processed sample decreased than that of untreated sample. Particularly, wear loss of the sample using the Ti mount considerably decreased.
Application of Metallography for the Slovak Nuclear Power Plants
Authors: Kapusňák Michal , Kupča Ľudovít
Published: April 2014

The austenitic cladding of liquid radioactive waste underground storage tanks was recently required to be under continuous corrosion surveillance with aim to monitor its corrosion stability until all radioactive waste will be processed and safely stored. Tanks are intended primarily to be used for long-term storage of radioactive waste water solutions and nascent sediments. Tanks are components of technology designed for post-processing of radioactive sediments by means of cement matrix fixation. This paper is dealing with an example of metallografical methods focused on corrosion processes monitoring using the special surveillance program. The brief information is presented for the preparation of specific long-run corrosion programme and experimental material samples evaluation. General view of the monitoring system is shown in Fig. 1.
Changes of Mechanical Properties in Response to Changes in the Microstructure of High Pressure Steel Cylinders Obtained by the Various Heat Treatments
Authors: Kučera Pavel , Mazancová Eva
Published: April 2014

The field of high-pressure steel cylinders (HPSC) and vessels used for the variety of applications especially for the CNG (Compressed Natural Gas) in automotive industry is still expanding. With increasing safety requirements, a need of new techniques applied in field of HPSC structural innovations comes into place. Conventional treatment provides generally sufficient parameters of HPSC, but the long-term goal is to achieve as high as possible strength properties vs. as high as possible notch impact strength, which is currently difficult fully accessible, because of the banded structures (segregation banding) created during the process of reversed extrusion and reversed hot rolling.