bluuebunny/crossref_metadata_2025 huggingface dataset:
Interference Fit Assembly of Micro-Parts Based on Microscopic Vision and Force
Authors: Zhang Juan , Wu Wen Rong , Shen Fei , Deng Yong Jun
Published: May 2015

To assemble easily damaged micro-parts safely in interference fit way, the assembly process is designed and the interaction force in assembly process is analyzed. The pose of micro-parts is aligned based on calibration of three microscopic vision systems from different directions. In addition, a control strategy based on feedback of vision and force is proposed to assemble safely. In the case of two micro-parts just contact, position of micro-part is adjusted based on force information to compensate pose alignment error and keep force in safe range. When micro-part is deformed as increased contact force, position of micro-part is adjusted based on force in the interference fit process and deformation of micro-part. Experimental results demonstrate the effectiveness of proposed methods.
Experimental Research on Nanostructure Fabricated by AFM Probe Combining with a CW Laser
Authors: Yang Li Jun , Cheng Bai , Wang Yang
Published: May 2015

Although the nanostructure machining by AFM probe assisted with laser has gain a great progress, few studies has been done on the optical fiber probe guiding the continuous laser to irradiate on AFM probe to machining nanostructure. Using this technology to create nanodot and nano-groove was presented in this paper. The law of how the experiment parameters influenced the results was summarized in the paper. The scale of nanodot is about 450nm, and nano-groove is about 40nm. When the fabrication is completed, the wear of the AFM probe was observed by SEM and drew a conclusion. In the method of nano machining by AFM Probe combining with a CW Laser, there will be a combined field to achieve the fabrication, and the method is better than mechanical characterization with AFM probe.
Constructing Dual Band Metamaterial Absorbers at Mid-Infrared by Employing Multi-Resonant Structures
Authors: Ma Wei , Wen Yong Zheng , Zhao Rui , Yu Xiao Mei
Published: May 2015

In this paper, we present two metamaterial absorbers (MMA) at mid-infrared using multi-resonant structures. The dual band MMAs employ the typical metal/dielectric/metal structure with 80 nm gold ground plane at the bottom, 190 nm SiO2 dielectric spacer in the middle and periodic gold patterns on top. The top resonant structure in MMA1 consists of a gold cross resonator ringed by four gold split-ring resonators (SRR) at the ends of the cross, while in the unit cell of MMA2, gold SRRs are placed at the four quadrants of the cross resonator. MMA1 shows two absorption peaks of 90.3% and 88.4% at 4.17μm and 4.86μm respectively, and the absorption peaks of MMA2 are observed to be 72.4% at 3.90μm and 48.0% at 5.66μm.
Structure Design of Large Travel One-Arm Bridge Type Z-Axis Nano-Positioning Stage
Authors: Fan Wei , Li Zhong Shen , Jiang Shao Yin
Published: May 2015

In some areas such as micro-mechanical, ultra-precision machining, nanotechnology, the high-precision positioning and very fine vertical scanning motion are needed urgently. Therefore, the Z-axis micro-displacement driving control technology has become the key technology in these areas. The piezoelectric ceramics actuator and stepper motor were integrated into hybrid linear actuator in Z-axis nanopositioning stage, and this can simplify the structure of the drive system. By calculating the gravity center of the vertical scanning system, and using single counterweight, a new one-arm bridge type structure was built. Appropriate tension and current sensors were also equipped in order to real-time monitor the drive status. It is feasible to balance the weight with this simplified system structure, and also guarantee the driving control accuracy of nanopositioning stage. Besides, in the structural design, the Abbe error can be reduced greatly by placing the stage center, grating ruler and displacement measurement centerline on the same line with grating reading head. The driving travel of nanopositioning stage is 150mm, and driving resolution is 1nm. The designing method introduced gives a scientific method and practical reference for the development of z-axis driving control system.
Implementation of Convolutional Encoder in Quantum-Dot Cellular Automata
Authors: Zhang Ming Liang , Cai Li , Yang Xiao Kuo , Cui Huan Qing , Wang Zhi Chun
Published: May 2015

As a nanoelectronic system, Quantum-dot cellular automata (QCA) is very likely to present high defect and fault rates. Therefore making QCA bits distortion-free is a necessary work. In this paper, we present the QCA based rate-1/2 and memory length-2 convolutional encoders that can generate one kind of error correcting codes from the perspective of information redundancy. Three schemes of layouts are presented and compared, and the majority-based type has the compactest layout and lowest latency. Our simulation results demonstrate that these encoders can all functionally work.
Theoretical and Experimental Studies on Microcavity Organic Light-Emitting Diodes with Different Emitters
Authors: Peng Cui Yun , Wei Meng Jie , Huang Rong Juan , Guo Kun Ping , Jing Yue Lin , Xu Tao , Wei Bin
Published: May 2015

We have theoretically and experimentally investigated the microcavity organic light-emitting diodes (MOLEDs) that enhanced the emission intensity and narrowed the spectra simultaneously. In this work, MOLEDs with the reflectivities of 70% and 90% have been successfully fabricated. Comparing to non-cavity OLEDs, the maximum forward electroluminescence intensity and the peak luminescence can be improved by 6.8 times and 2.2 times, respectively. The full width at half maximum could be sharply narrowed to 10 nm. The different configurations of MOLEDs with varied emitting layers have also been evaluated which fitted well with the experimental results.
The Thermal Decomposition Behavior of Graphene Oxide/HMX Composites
Authors: Zeng Gui Yu , Zhou Jian Hua , Lin Cong Mei
Published: May 2015

Graphene oxide (GO) was prepared by Hummers method and GO/1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) composite was prepared via an ultrasonic compounding method. The structure of GO was characterized using XRD and SEM, the thermal decomposition of HMX and GO/HMX composite was analyzed by DSC/TG test. The results show that interlayer space of GO increases markedly, the thermal decomposition process of HMX can be promoted with the nanolayer structure of GO, resulting the reduced thermal decomposition activation energy of about 50 kJ/mol with 1% GO.
High-Frequency InP-InGaAsP Heterojunction Phototransistor Employing a UTC Structure
Authors: Jiang Zhi Yun , Xie Hong Yun , Zhang Wan Rong , Zhang Liang Hao
Published: May 2015

In this paper, the working mechanism and high characteristics of an InP/InGaAsP uni-traveling-carrier (UTC) double hetero-junction phototransistor (DHPT) has been analyzed. The UTC-DHPT employs a heavy doping base and two hetero-junctions to realize UTC structure to ease the contract between HPT responsivity and HPT working speed. Optical responsivity and optical transit frequency are analyzed physically through illustrated several kinds of paramistic capacitors in BE junction and BC junction under different electrical bias, optical bias and combined electrical and optical bias in this work. The results show that three-terminal (3T) working mode with combined electrical bias and optical bias in base achieves a highest maxim fT of 120GHz at collector current of 30mA and keeps the same optical responsivity (37.5A/W) compared with two-terminal (2T) working mode.
Surface Micromachined Mirror Based on Pre-Stress Comb-Drive Actuator
Authors: Wang Wei Min , Yan Sheng Mei , Wang Qiang , Qiu Chuan Kai , Chen Ze Xiang , Fan Bin
Published: May 2015

A micromirror fabricated by surface micromachined process is developed. The developed micromirror contains four pre-stress comb-drive actuators, which support tip/tilt/piston degrees of freedom. Pre-stress comb-drive actuators have the advantage of large displacement and fast response. Prototype is fabricated by a commercially available MEMS surface micromachined process. Experimental results indicate that the device can realize designed function and have the potential in MOEMS applications.
Novel Wind Energy Harvesting Device for City Building Based on ZnO Films Array
Authors: Wu Shao Hua , Du Li Dong , Zhao Zhan , Kong De Yi , Fang Zhen
Published: May 2015

A kind of novel wind energy harvesting device with square ZnO piezoelectric thin films array structure has been investigated in the article. It is designed and fabricated for ambient wind energy on high buildings in city blocks particularly. Ordinary elements of wind energy harvesting are various windmills or turbines, they are usually expensive and noisy, and are not suitable to be used in the crowed city. The novel wind energy harvesting device is fabricated by Micro Electro Mechanical System (MEMS) technology in order to avoid the deficiencies mentioned above. The films array has a multilayer structure with five layers, and has a thickness of about 2.5μm. The maximum open circuit output voltage of the device reaches 2.81V, and its maximum output power density is 23.39nW/cm2.
VCuxOy Thin Film by Magnetron Sputtering as Cathode Material for Thin Film Lithium-Ion Microbatteries
Authors: Lin Jie , Guo Jian Lai , Liu Chang , Guo Hang
Published: May 2015

A Cu doped V2O5film for lithium-ion batteries is prepared by magnetron sputtered using a vanadium target. Coppers are doped in varying proportions to investigate the effect of doping on the electrochemical properties. In comparison, the surface of doped samples is smooth and uniform. And the results of electrochemical tests indicate that the proper doped films (V: Cu=8: 1 by area) exhibit better cycle performance, wider voltage plateaus and higher capacity than other samples.
A 3D All-Solid-State Thin Film Microbattery with Inverted Pyramid Arrays
Authors: Lin Jie , Guo Jian Lai , Liu Chang , Guo Hang
Published: May 2015

A 3D all-solid-state thin film lithium-ion microbattery (TFLM) with inverted pyramid arrays is fabricated by microfabrication technology. Compared with 2D TFLMs, the effective area of this 3D TFLM increases more than 30%. The 3D TFLM prepared by magnetron sputtering is composed of LiCoO2 cathode, LiPON solid electrolyte, and copper doped SnOx anode. The 3D TFLM is tested by electrochemical measurements, and the results show that it has reliable capacity and excellent performance.
Asymmetric Design of Anode and Cathode Current Collectors for Micro Direct Methanol Fuel Cells
Authors: Zhang Yu Feng , Zhang Shu Bin , Ma Ze Zhong , Chen Hai Long , Liu Xiao Wei
Published: May 2015

This paper studied the combined effect of anode and cathode current collectors on the behavior of water and methanol crossover in micro direct methanol fuel cells (μDMFC). A two-phase, two-dimensional, isothermal model was built to analyze the mass transport behavior in the membrane electrolyte assembly (MEA). The results show that the distribution of methanol exhibits uniform concentration feature over the anode porous area with the asymmetric anode and cathode current collectors. Also, lower water content gradient across the membrane is found. Comparing experiments were conducted to verify the simulation results. Two passive μDMFCs were fabricated and tested. The cells presents almost the same performance at relatively low methanol concentration. However, an increase of 10% cell performance (from 27.5 mW.cm-2 for symmetric current collectors to 30.3 mW.cm-2 for asymmetric current collectors) at 5 mol.L-1 methanol solution was observed. This reveals that the couple of asymmetric current collectors induced the methanol to distribute uniformly and largely suppressed the water and methanol crossover.
Study on the Energy Harvesting Performance of PE Cantilever Beam
Authors: Liu Hai Peng , Gao Shi Qiao , Jin Lei
Published: May 2015

Harvesting ambient vibration energy through piezoelectric (PE) means is a popular energy harvesting technique. The merit of applying PE means to supply energy for microelectronic devices is that they can reduce the battery weight and possibly make the device self-powered by harvesting mechanical energy. This investigation will examine the energy generating performance of miniature PE cantilever beam through theoretical modeling, simulation and experiment testing. Through the theoretical analysis of the piezoelectric energy harvesting structure, the expression of open circuit voltage output is obtained. Using ANSYS software, the working performance of piezoelectric cantilever beam is analyzed. On the basis of theoretical analysis and simulation optimization, a set of experimental system is established to test the energy harvesting performance of the piezoelectric cantilever beam. The testing result shows that the harvested energy by the piezoelectric cantilever beam could supply electrical power to some micro electrical devices.
Numerical Optimization Approach of the Gap between the Magnet and Coil for Electromagnetic Vibration Energy Harvesters Design
Authors: Lei Yi Ming , Wen Zhi Yu
Published: May 2015

In the design of the micro electromagnetic vibration harvester, an important goal is maximization of the magnetic flux linkage gradient, which directly determines the induced voltage and output power of the electromagnetic vibration harvester. This paper established a numerical model based on structure of the electromagnetic vibration energy harvester. An analytic expression for the magnetic field of rectangular permanent magnets is used to build up an electromagnetic coupling model. The magnetic field distribution of the rectangular permanent magnet was analyzed. The effects of the gap between the magnet and the coil on the load voltage of the electromagnetic vibration energy harvester were investigated. According to the formula, the magnetic flux linkage and flux gradient were calculated to optimize the geometrical parameter of the magnet and coil. The method and boundary conditions of optimizing the gap between the magnet and coil were presented. The maximum output voltage can be obtained by optimizing the gap between the magnet and the coil. A simple prototype was fabricated and measured to validate the theoretical deducing and the feasibility of method.
Stabilization of Pickering Emulsions by Bacterial Cellulose Nanofibrils
Authors: Fu Wei , Liu Yang , Yang Chen , Wang Wen Hua , Wang Man , Jia Yuan Yuan
Published: May 2015

In order to develop safe and sustainable food and pharmaceutical emulsions, bacterial cellulose (BC) nanofibrils were prepared to stabilize maize oil/water Pickering emulsions. The influence of BC content and pH value on the emulsion stability was explored. Droplet diameters decreased with BC contents in emulsions. At pH 12, the emulsions were most stable among all tested pH values. The transformation of emulsion structure from liquid to gel-like at 8-15°C with BC content higher than 1.55 g/L is predominantly depended on the viscoelastic entangled BC network. These results can have meaningful inspiration of designing edible food and pharmaceutical emulsions.
In Situ Synthesis of the Hollow Silica Microspheres with Porous Surface by Using Chemical Modified Pollen Grains as Biotemplate
Authors: Cao Feng , Li Dong Xu , Wu Zheng Ying
Published: May 2015

Hollow silica microspheres with porous surface were synthesized by using the pollen grains as biotemplate through an in-situ synthesis process, in which the pollen grains were surface modified by ammonium oleate. Scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption-desorption porosimetry analyzer were applied to investigate the as-prepared microspheres. Bovine serum albumin was used as the model drug to estimate the adsorption property. And the effect of the different amount of tetraethoxysilane during the synthesis process were discussed in this paper. Results indicated that the hierarchical network of the pollen wall could be well replicated through this method, in which the hydrophobic interaction between the pollen wall and surfactant as well as the electrostatic interaction between the surfactant and the hydrolysate of tetraethoxysilane were considered as the key factors for the replication. The hollow silica microspheres have loading capacity for the model drug, and the adsorption property of this microsphere could be easily adjusted by changing the amount of tetraethoxysilane.
CMOS Amplifier for Neural Signal Recording Applications
Authors: Zhang Zhang , Cheng Zheng Xi , Zhuang Yi Wei
Published: May 2015

A low power low noise CMOS amplifier with integrated filter for neural signal recording is designed and fabricated with CSMC 0.5 μm CMOS process. DC offsets introduced by electrode-tissue interface are rejected through a feedback low-pass filter. The bandwidth of the amplifier is in 3.5Hz-5.5KHz range, and the gain is about 48dB in the midband. AC input differential mode voltage range is 10mV, and DC input differential mode voltage range is 180mV. The amplifier can accommodate 180mV DC offsets drift and 10mV neural spikes. The neural probe array is integrated directly on the surface of the amplifier array chip, and is tested in saline solution, and also is implanted in rats in vivo , the results of the experiments show that the amplifier is suitable for neural signal recording. The power dissipation is about 14μW while consuming 0.16 mm2 of chip area, which satisfies implantable devices requirements.
A Biological 3D Printer for the Preparation of Tissue Engineering Micro-Channel Scaffold
Authors: Zhang Ya Nan , Liu Yuan Yuan , Li Yu , Li Shuai , Hu Qing Xi
Published: May 2015

The clinical applications of tissue engineering are still limited by the lack of a functional vascular supply in tissue-engineered constructs. In order to improve the pre-vascularization of tissue-engineered scaffold during in vitro culture, in this study, based on three-dimensional (3D) printing technology, using the crosslinking effect of coaxial fluids (sodium alginate and CaCl2) to prepare vessel-like hollow gel fibers, then layer by layer overlapping into 3D scaffold. The biological 3D printing platform was successfully developed and a coaxial nozzle module was introduced to generate a CaCl2-in-Alginate coaxial microfluidic. The inner core diameters of the prepared hollow gel fibers were 220~380 micrometers. In addition, the influence of materials concentration and dispensing rates on hollow fiber dimension were investigated, the cell-encapsulated in the printed hollow fibers was realized and the viability of endothelial cells (ECs) was studied with Laser scanning confocal microscopy (LSCM) and Live-Dead cell staining. The 3D scaffold built by hollow fibers could improve the phenomenon of diffusion constrain and enhance the survival rate of those ECs growing at a greater depth in the construct. This study provides a new theoretical basis for the vascularization of bone scaffold.
Specific Detection of Staphylococcus Enterotoxin B in Milk Using Piezoresistive Cantilever Aptasensor
Authors: Zhao Rui , Wen Yong Zheng , Ma Wei , Yang Jian Cheng , Yu Xiao Mei
Published: May 2015

In this paper, an aptasensor with high sensitivity and rapid response was developed for the detection of staphylococcus enterotoxin B (SEB) by using thiol-modified piezoresistive cantilever. Thiol-modified aptamers, acting as the functionalized sensing elements, were immobilized on the nanogold-coated surface of the sensing cantilever as agents for detecting SEB. By using the functionalized aptasensors, different concentrations of SEB were detected with a wide detection range of 6-100 ng/mL and a quick response in milk. The experimental results indicated that the cantilever-based aptasensors had sufficient sensitivity for the detection of SEB in real food commodities and might provide an economical platform for on-site detections of different toxicants with the advantages of portability, high sensitivity, and rapid response.
Research of Magnetic Characteristics of the Split-Drain MAGFET Based on Nano-Polysilicon TFTs
Authors: Zhao Xiao Feng , Guan Han Yu , Lv Mei Wei , Bai Yi Nan , Wen Dian Zhong
Published: May 2015

The split-drain magnetic field effect transistor (MAGFET) based on nanopolysilicon thin film transistor (TFT) is fabricated on <100> high resistivity silicon substrates by (complementary metal oxide semiconductor) CMOS technology in this paper. It contains source (S), drain1 (D1), drain2 (D2) and gate (G), and adopts nanopolysilicon thin films and nanopolysilicon/high resistivity silicon heterojunction interfaces as the magnetic field sensing layers. The influence of the channel size and shapes on the transistor, are studied to further improve its magnetic sensitivity. When the ratio of channel length and width (L/W) of MAGFET is 80 μm/160 μm, VDS=5.0 V, the MAGFET with convex channel has higher magnetic sensitivity than the rectangle and concave, the absolute current magnetic sensitivity SI and the absolute voltage magnetic sensitivity SV of the proposed sensor reach the maximum values, and are 0.021 mA/T and 55 mV/T, respectively.
The Application of Micro-Flow Extrusion Forming Technology in the Denture Preparation
Authors: Zhou Jing , Duan Guo Lin , Zhu Dong Bin , Cai Jin
Published: May 2015

The forming process of denture preparation based micro-flow extrusion was researched. The dental ceramic materials having health care function was preparation. Through analysis and calculation, the rheological properties of the ceramic slurry confirmed to be pseudo-plastic fluid . The extrusion head as a key part was designed. The pressure distribution and velocity distribution of the internal flow field of extrusion head were simulated by using START-CD software ,the analysis result can used to guide the optimal design of extrusion head.
Yeast Cells Immobilization in Microfluidic Channels Based on a Self-Polymerized Nano-Film of Poly(Dopamine)
Authors: Chen Xing , Zhang Lu Lu , Sun Jian Hai , Li Hui , Cui Da Fu
Published: May 2015

In this paper, an effective, simple and universal method for cell immobilization was developed. A self-polymerization nanofilm of poly (dopamine) was used to fix yeast cells in microfluidic channels. The surface morphology of the poly (dopamine) film was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. Water contact angles (WCA) was also used to characterize the surface property of the poly (dopamine) nanofilm. The WCA on the PDMS substrates rapidly decreased from 105° to 59.8° with an increase in poly (dopamine) coating time. The interfacial process of dopamine self-polymerization and the cell immobilization were measured in a label-free and real-time mode by a surface plasmon resonance (SPR) instrument. Finally the immobilized yeast cells were observed by using a light microscope. From the experimental results, the yeast cells can be easily immobilized on the microfluidic channels modified with the nanofilm of poly (dopamine), which will hold great potential for the immobilization, detection and further analysis of other suspension cells, such as blood cells.
Preparation and Characterization of Tissue Engineering Scaffolds by Composite Molding of 3D Printing and Electrospinning
Authors: Ma Yun Min , Liu Yuan Yuan , Chen Hai Ping , Hu Qing Xi
Published: May 2015

Currently, the developed electrospinning technique is capable of producing sub-micron diameter fibers, has better bionic of the extracellular matrix (ECM) on the size and morphology. Joining the nanofiber network into the porous macro scaffolds by the association of electrospinning with 3D printing technology can effectively support bionic microenvironment and improve the cell compatibility of scaffolds. We prepared the GE/CA-PCL scaffold by the composite approach, and characterized the morphology, cell compatibility and mechanical properties of scaffolds compared to the GE/CA scaffold prepared by single 3D printing technology. The composite molding process of 3D printing and electrospinning is a promising technique used for preparing scaffolds for tissue engineering and clinical medicine.
Graphene Field Effect Transistor’s Circuit Modeling and Radio Frequency Application Study
Authors: Zhu R. , Zhang Y. , Luo J. , Chang S. , Wang Hao , Huang Q. , He Jin
Published: May 2015

In this paper, a large signal circuit model of graphene field effect transistor (GFET) is described accurately by Verilog-A language, which is suitable for radio frequency circuit design and can be applied in HSPICE and ADS directly. Then two typical radio frequency (RF) circuits, frequency multiplier and mixer, are based on this GFET circuit model. The proposed circuits’ performance are analyzed respectively in 10GHz, 15GHz and 20GHz, and GFET’s application foreground in radio frequency area is discussed.
Synthesis and Dispersity of YBCO Powder Produced by Oxalic Acid Precipitation Method
Authors: Wang Ai Qin , Han Hui Hui , Li Min , Xie Jing Pei , Wu Qing Jie , Ma Dou Qin
Published: May 2015

The YBCO powder was prepared by oxalic acid precipitation method and consequent annealing. The correlation between pH values of oxalic acid solution and the precipitation percentage of precursors were analysed based on thermodynamics analysis. The differential scanning calorimetryanalysis (DSC) was used to confirm the synthetic technological parameter. The phases of powder in each process were investigated by XRD. The microstructures of each powder were tested by SEM and TEM. The mean grain size was calculated by the scherrer’s equation. The test results indicated that the YBCO powder with high purity, less impurities, smaller particle, but severe agglomeration, was Y123 when annealing at 900°C. However, adding dispersants could effectively solve the severe agglomeration. The size of YBCO particles was nanosized and coincided with the calculation.
The Dilute Magnetic Properties of Monolayer MoS2 Doped with Transition Metal Fe and VA Atoms
Authors: Lan Lan , Cao Jia Mu , Cao Yi Jiang , Xu Dian Shuang , Zhou Jing
Published: May 2015

The two-dimensional material MoS2 has attracted a growing attention due to its potential applications in electronic devices in recent years [1,2,3], and the monolayer MoS2 is a direct gap semiconductor with a band gap of 1.8eV [4]. In the existing studies, it has indicated that MoS2 can get an available magnetism with doping transition metal atoms [5], and is expected to be a new generation of diluted magnetic semiconductor (DMS) [6,7]. Moreover, we found that Fe-doped MoS2 could present a strong magnetism but a semimetal characteristic, losing its original semiconductor properties while obtaining magnetism. Therefore, it is necessary to explore some methods to make monolayer MoS2 exhibit both magnetic and semiconductor properties. In this paper, we propose the method of N, Fe atoms co-doping to achieve this objective. The structural, electronic and magnetic properties of MoS2 doped with transition metal Fe and VA atoms have been investigated by first principle calculations based on density functional theory. The 3×3×1 supercell of monolayer MoS2 as a calculation model has been used. The result shows that pure MoS2 has no magnetism, while Fe-doped MoS2 exhibits a good magnetism about 1.849μB but a semimetal characteristic. This is due to that Mo-4d, S-2p, Fe-3d states has a strong coupling around the Femi energy for the introduction of Fe atom, and the Femi energy only pass through the spin-up density of states. For the co-doping with VA atoms and Fe atoms, it is found that the magnetic moment of Fe-N, Fe-P and Fe-As co-doped MoS2 is 0.956μB, 0.775μB, 0.782μB. Moreover, the Fe-N co-doped MoS2 presents semiconductor characteristics, in contrast, Fe-P and Fe-As co-doped MoS2 appear semimetal properties. It indicates that the semimetal characteristic of Fe-doped MoS2 could change into indirect band gap semiconductor due to the introduction of N atom. The band gap is 0.2eV. Our study demonstrate that the method of Fe, N co-doping could make MoS2 have good magnetic and also semiconductor properties at the same time.
An Investigation on Resistive Switching Characteristics Induced by HfOx and Electrode Interfaces
Authors: Chen Xiao Rong , Feng Jie
Published: May 2015

Pt/HfOx/Pt resistive switching devices with symmetric electrodes were fabricated. Bipolar resistive switching (RS) behaviors and unipolar behaviors were then observed under a positive/negative bias applied to the top electrode (TE). A comparison and analysis of bipolar/unipolar RS behaviors under different voltage polarities was then performed.The results demonstrated that bipolar RS was achieved via a drift of anion (O2-) under the electric field resulting in the rupture and recovery of filaments at the interface. When the filaments dissolved and formed at the interface near BE, the performance of the bipolar RS devices was better. However, for unipolar RS devices, when filaments dissolved and formed at the interface near TE, the performance was even better. These results indicated that a drift of O2-caused by electric field and a diffusion of O2-induced by Joule heat were the main reasons for unipolar RS. The different characteristics of the bipolar and unipolar devices can be attributed to the existence of a different number of defects at the active interface of the devices. This was where the rupture and recovery of filaments occurred. The results also indicate that the active interface is more important than other interfaces for RRAM performance.
Preparation of TiO2 Nano-Film by Anodic Oxidation Method and its Hydrophobic Modification
Authors: Liu Feng Bin , Jing Bao
Published: May 2015

TiO2nanofilms with different morphology were prepared by anodic oxidation method by changing the electrolyte concentration, anodization voltage, anodization time and anode-cathode distance. The surface of the nanofilm was modified by a kind of solution which consists of lauric acid and hexadecane. And this article find a proper electrolytic time, a medium voltage, a proper anode-cathode distance and a lower electrolyte concentration are beneficial to the hydrophobicity of the nanofilm.
Research on Microstructure and Wear Resistance of Cast-Penetrated Layer Strengthened by Nano-Sized TiN Intermediate Alloy
Authors: Xie Jing Pei , Shao Xing Hai , Liu Shu , Wang Feng Mei , Wang Ai Qin , Ma Dou Qin
Published: May 2015

High-Cr cast-penetrated layer contained nanometer ceramic particles was formed on the surface of the medium carbon steel ZG250-470 by adding nanoTiN intermediate alloy powder to cast-penetrated agent. Microstructure and wear resistance of the strengthened cast-penetrated layer were studied. The results showed that: compared with not adding intermediate alloy, there were finer and more uniform microstructure and better high temperature and high speed wear performance of strengthened cast-penetrated layer strengthened by nanoTiN intermediate alloy. Strengthening effect would be best by adding the intermediate alloy containing rare earth. By adding intermediate alloy containing Ni, the best high temperature wear resistance of cast-penetrated layer could be obtained.
Preparation of Nano α-Fe2O3 Powders and Characterization of their Photo-Catalysis Capacities
Authors: Zhang Nan Yang Sheng , Zen Yan An , Wang Shuang Bao , Zhu Bing
Published: May 2015

The hematite α-Fe2O3 is considered as low cost-effective semiconductor for photo-catalysis recently. We have prepared high quality α-Fe2O3 nanopowder by sol-gel method, as shown by XRD diffraction, we could find that the powder are as small as 5-10nm. We also characterize the photo-catalysis properties on such magnets, which show unique photo-induced catalysis capacity.
Effect of Hydrophilic and Hydrophobic SiO2 Particles on Performances of PI/Al2O3 Composite Films
Authors: Li Yuan Yuan , Liu Li Zhu , Shi Hui , Weng Ling , Cui Wie Wei
Published: May 2015

In this paper, we mainly analyzed the different influence of hydrophilic SiO2 particles and hydrophobic SiO2 particles on the properties of PI/Al2O3 films. PI/Al2O3/SiO2(hydrophilic) films and PI/Al2O3/SiO2(hydrophobic) films with 16 wt% content of Al2O3 and 3 wt‰, 5 wt‰, 7 wt‰ content of SiO2 respectively were prepared by in-situ polymerization method. Firstly, the hydrophilic SiO2 particles and hydrophobic SiO2 particles were investigated by transmission electron microscopy (TEM), infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results showed that the average sizes and infrared characteristic peaks of two kinds of SiO2 particles were similar, and two kinds of SiO2 particles were amorphous inorganic particles. Then the morphology of the composite films was characterized by scanning electron microscopy (SEM), and the mechanical properties, the breakdown field strength and corona resistant time were tested and analyzed. Results indicated that inorganic particles added to PI/Al2O3/SiO2(hydrophilic) films dispersed better than that of PI/Al2O3/SiO2(hydrophobic) films. When the content of SiO2 particles was 5 wt‰, the mechanical properties and corona resistance of PI/Al2O3/SiO2(hydrophilic) films were best, the tensile strength, elongation at break and corona resistance times of the films were: 132.44 MPa, 12.64%, 378 min, respectively. The breakdown field strength of PI/Al2O3/SiO2(hydrophilic) films was only 211.15 kV/mm, and inferior to that of PI/Al2O3/SiO2(hydrophobic) films (232.08 kV/mm).
The Effect of Thermal Accumulation to the Field Emission Properties of the Carbon Nanotubes
Authors: Yan Fei , Li Nan Nan , Chen Lei , Jin Da Zhi , Xiang Wei
Published: May 2015

In this paper, we report a recent experimental observation of the effect of thermal accumulation to the field emission properties of the carbon nanotubes. The carbon nanotubes are grown on Ni by CVD. We compare the field emission characteristics of carbon nanotubes cathodes under DC and pulse mode. Our research shows that the higher current and higher current density could be acquired by suppressing the thermal accumulation. The Fowler-Nordheim plot shows a good linear fit, indicating that the emission current of carbon nanotubes follows Fowler-Nordheim behavior.
Effect of Ammonia as an Inert Solvent on Structure and Separation Performance for Oil/Water Mixtures of PVDF Porous Membranes
Authors: Cui Wei Wei , Liu Jing Qiang , Liu Li Zhu , Xu Wen Hua , Li Yuan Yuan , Gao Zhan Qiang
Published: May 2015

Porous polyvinylidene fluoride (PVDF) membranes were prepared from PVDF and N-methyl-2-pyrrolidone (NMP) solution system using immersion precipitation phase inversion technique with ammonia as an inert solvent additive. The effects of ammonia amount on pore size, surface morphology, crystallinity, hydrophobic property, oil uptake and water-oil separation performance of the membranes were investigated. It was found that all membranes had an interpenetrating porous structure. The increase of ammonia amount led to significant variations in morphology. Lots of tiny apophysis formed on the membrane surface, pore size deceased, and pore density increased with the increase of ammonia amount. The crystallinity decreased with increasing ammonia amount, and hydrophobic property was improved. The membrane showed high oil uptake and effective separation function of oil-water mixture.
Ejection and Motion Behaviors Simulation for Multi-Jet Electrospinning
Authors: Li Wen Wang , Luo Zhi Wei , Wang Xiang , Zheng Jian Yi , Zheng Gao Feng , Sun Dao Heng
Published: May 2015

Multi-jet ejection is the key factor to promote the industrial application of electrospinning technology. Simulation model based on Maxwell theory was built up to investigate the ejection and motion behaviors of multi charged jets. The charge Coulomb repulsive force among adjacent jet was introduced into the simulation model, which enhanced the instability motion and promoted the stretching process of charged jets. The stretching ratio of charged jet increased with the increasing of injection distance, applied voltage, distance between spinneret and collector. But stretching ratio of charged jet decreased with the increasing of distance between charged jets. Stretching ratio in multi-jet electrospinning was larger than that in single-jet electrospinning. The maximal stretching ratio of charged jet was larger than 9000 in the nine jets electrospinning mode. This work provided a good method to investigate the controlling technology of multi-jet electrospinning.
Measurement on the Mechanical Properties of SiC Thin Films Based on Square Thin Films Theory
Authors: Chen Yao Min , Dong Pei Tao , Wu Xue Zhong , Wu Yu Lie
Published: May 2015

SiC films made of different methods may have different mechanical properties, so their mechanical properties need to be determined by mechanical property measurement [1]. Since SiC films have stable chemical properties, it’s very difficult to be etched [2]. This paper introduce a method for SiC films mechanical property testing without processing SiC. Moreover, in view of the lack of square SiC films’ mechanical properties research, this paper also do simulation on it.
Effect of Reaction Inhibitors on Synthesized Silver Nanostructures via Solvothermal Method
Authors: Xie Hui , Xiong Na Na , Liu Jian Zhuang , Zhao Yu Zhen , Wang Yue Hui
Published: May 2015

In this paper, silver nanostructures were synthesized via a solvothermal method by reducing silver nitrate with ethylene glycol in the presence of poly (vinylpyrrolidone) and using NaCl, MgCl2, AlCl3, FeCl3, Fe2(SO4)3, NaOH, NaBr and Na2S as reaction inhibitor, respectively. Characteristics of the as-prepared silver nanostructures were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-visible (UV-vis) absorption spectrum. It is found that the mixture of nanoparticles and nanorods and nanowires can be observed in the AlCl3and NaOH systems, the nanorods as main products can be obtained in the MgCl2and NaCl and Fe2(SO4)3systems, the large scale silver nanowires as main products can be obtained in the FeCl3and Na2S systems, especially in the Na2S system, silver nanowires are very long and curved. The results indicated the reasons of the effect of the reaction inhibitors on the morphologies of silver nanostructures depend on the solubility product constant of silver salt which formed with silver ion and inhibitor anion ion in the initial stage and the properties of metal cationic ion of inhibitor. The smaller solubility product constant of silver salt or the presence of Fe3+or low valence metal iongreatly facilitate the formation of one-dimensional silver nanostructures, especially to nanowires.
A Novel High Precision Analytic Potential Function for Diatomic Molecules
Authors: Yu Chang Feng
Published: May 2015

A new analytical potential energy functions is presented, the potential energy function is examined by 13 examples of different diatomic molecules or ions——homonuclear ground-state for neutral diatomic molecules, heternuclear ground-state for charged diatomic molecular ion, heternuclear excitation-state neutral diatomic molecules ,heternuclear excited-state for charged diatomic molecular ion, homonuclear excited-state for neutral diatomic molecule , homonuclear excited-state for charged diatomic moleculeetc.. as a consequence, the theoretical values of the vibrational energy level of molecules calculated by the potential energy function are in high-precision consistent with RKR data (Rydberg-Klein-Rees) or experimental data.
Effects of n-Type Dopants on Electronic Properties in 4H-SiC
Authors: Tang Jin Long , Zhong Jun Nan , Wen Cai
Published: May 2015

Based on first-principles calculations, we have investigated atomic and electronic structures of 4H-SiC crystal doped by N, P and As elements as n-type dopants. We have obtained the bond lengths of the optimization system, as well as the impurity levels, the band structure and the density of states. The results show that the higher impurity level above the Fermi level is observed when 4H-SiC doped by N with concentration as 6.25% in these dopants, and the band gap of 4H-SiC decreases while the doping concentration or the atomic number of dopant increases.
Synthesis of Nano-Al with Fe2O3 Nanowires to Realize Core-Shell Composite Materials Arrays Based on Colloidal Templates
Authors: He Si Min , Chen Jin , Fang Kuang , Qiao Zhi Qiang , Li Jin Shan
Published: May 2015

Controlled composite materials arrays have been widely applied for their unique physical and chemical properties, with the aim of developing nanodevices functionality. Nanosphere lithography is a successful technique for fabricating highly ordered arrays of various materials. In this work, the polystyrene colloidal crystal template in large area on Si substrate was obtained via dipping method. The thickness of the single layer template fabricated can be precisely controlling the particle concentration and the film formation speed. The ordered arrays of Fe2O3 nanowires were obtained via convenient spin method on this template and heat treatment subsequently. Finally, the uniform Al/Fe2O3 arrays were produced by magnetron sputtering method. These periodic composite arrays cover large area substrates (of dimensions > 1 cm × 1 cm) and are uniform in terms of nanowire height and density. The arrays thickness and gaps between nanowires are easily controlled by either the diameter of colloidal crystal or the parameters of magnetron sputtering.
The Study on the Selectivity Ratio of SiC/Epoxy Resin Based on ICP Etching
Authors: Hu Jiang , Zhou Shun , Cai Chang Long , Zhu Yu Feng , Hu Shuai , Liu Wei Guo
Published: May 2015

SiC molds have excellent performance for high-temperature molding optical lenses. The stable physical and chemical properties of SiC results in the difficulty of manufacture high precision SiC molds. Using etching method can manufacture SiC molds apace and accurately, which is used for Micro-embossing needs to study the suitable selectivity ratio of SiC and the anti-etch layer-epoxy resin. The etching gas is SF6 and O2. Under different ICP power, bias voltage, the gas mixing ratio and other parameters, it has studied the influence of various factors on the etching ratio, the etching rate and the etching quality. Experiments show that under the parameters of SF6 flow of 80sccm, O2 flow of 5sccm, ICP power of 1200w, bias power of 70w, temperature of 30 °C, and pressure of 30mTorr, the SiC etching rate is 246.44nm/min, and the epoxy etching rate is 616nm/min. The SiC/epoxy resin etching ratio is stable at 1:2.5. The roughness of SiC is 1.2nm (Sa= 1.2nm). The anisotropic of etching is good.
The Influence of Polyhedral Oligomeric Silsesquioxane on Heat Resistance and Curing Kinetics of Potting Materials
Authors: Fan Jing Hui , Jing Hua , Wu Ju Ying
Published: May 2015

The influence of polyhedral oligomeric silsesquioxane on heat resistance and curing kinetics of potting materials were studied. The results showed that POSS can promote the cure, but did not change the potting materials curing mechanism. The research results have important significance for improving the performance of potting materials in electronic products.
Preparation and Mechanical Properties of Ultra-Fine Grain Medium-Carbon Steel Based on Equal-Channel Angular Pressing
Authors: Wang Jian Min , Hou Wen Tao , Lu Lin
Published: May 2015

A new technology of preparing submicron medium-carbon steel quickly using martensitic steel by equal-channel angular pressing is developed. The technology combines martensite phase transformation with severe plastic deformation. In this research, martensitic steel is heated to 923K quickly and held for appropriate time, then equal-channel angular pressing is implemented. Supersaturated ferrites of average grain size within 0.5μm are obtained by the interaction of dislocation intersection, dynamic recrystallization and strain-induced phase transformation. At the same time, strain-induced phase transformation leads to dispersive precipitation of supersaturated carbon particles in the form of carbide inside grains or in grain boundaries. The optimal size of ferrite grains and the optimal distribution of carbides are acquired by controlling tempering temperature and time. The results show that ultra-fine grained materials prepared by this technology possess superior thermal stability.
Tribological Properities of Oil-Based ZnO Nanofluids
Authors: Ran Xu , Yu Xue Ying , Wang Yong , Xiao Zhe
Published: May 2015

In this research, the friction and wear characteristics of nanofluids were studied through experimental investigation by dispersing ZnO nanoparticles into 60SN base oil. Oleic acid was used as a surfactant for the improved dispersibility and stability of nanofluids. Nanoparticles were dispersed using a magnetic stirring apparatus and ultrasonic bath. The micro/nano mechanics comprehensive test system UNMT- 1 wear testing machine was used to evaluate the friction properties. The wear track was measured by a Zeiss laser confocal microscope and scanning electron microscope (SEM). The effect of ZnO nanoparticles on the friction and wear performance of the nanofluids was investigated, and the optimal ratio between the surfactant and particle concentration was studied. The results showed that oil-based nanofluids with ZnO nanoparticles could reduce friction and wear under certain conditions. The optimally stable concentration of the fluids was that the oleic acid adding quantity was 5wt%～10wt% and ZnO nano-particles was 0.2wt%～0.7wt%. And when the oleic acid adding quantity was 10wt% and ZnO nanoparticles was 0.2 wt%, the nanofluids had best friction-reducing and anti-wear properties.
Effect of Flow Rate of Slurry in Micro-Channels on the Consistency of Polishing Rate
Authors: Li Yan , Sun Ming , Liu Yu Ling , Wang Ao Chen , Tang Ji Ying , Fan Shi Yan
Published: May 2015

According to the Bernoulli equation and Darcy formula, the flow model of slurry in micro-channels was established, it indicated that slurry viscosity is the main factor affecting the slurry mean velocity. According to the characteristics that liquid viscosity is mainly determined by the liquid temperature and the property that mechanical friction can improve the liquid temperature, the effects of slurry temperature, working pressure and polishing speed on the heterogeneity of polishing rate were investigated. The results showed that the effect of removal rate of each parameter on the central part of the copper film can be described as: slurry temperature > working pressure > polishing speed. In order to obtain the best planarization process, through the central composite experimental method, the technological parameters were optimized regarding the heterogeneity of polishing rate as response value. It was finally concluded that: when the slurry temperature was 21.60°C, the working pressure was 8.83kpa, the system speed was 43.92rpm, the predicted minimum value of the heterogeneity of polishing rate (HOPR) was 0.0574.
Effect of Elliptical Dimples on Hydrodynamic Lubrication
Authors: Ji Jing Hu , Wang Hao , Fu Yong Hong
Published: May 2015

This paper develops an analytical model to investigate the effect of elliptical dimples on hydrodynamic lubrication of surface contact. The hydrodynamic pressure generated by elliptical dimples is solved by the multi-grid method. The evaluation criterion of hydrodynamic effect of dimensionless average pressure is calculated and presented with the variation of elliptical dimple depth, area density, slender ratio and inclination angle. The results indicate that geometrical parameters of elliptical dimples have an obvious influence on the hydrodynamic pressure. The hydrodynamic lubrication performance can be ameliorated by optimizing the geometrical parameters of elliptical dimples according to the operating parameters of the mechanical components.
The Research of Turn-On Time for Silicon Micromechanical Gyroscope on a Chip
Authors: Bian You , Shi Qin , Xia Guo Ming
Published: May 2015

On the basis of analyzing the boot process of silicon micromechanical gyroscope on a chip at room temperature, -40 °C and 60 °C constant temperature environment, for the character that the gyroscope can realize the compensation function and possess temperature-sensitive output model, This paper analyzes the relationship between the bias and temperature meter, and presents compensation method of the initial bias so as to reduce different turn-on time caused by the variation with the temperature of working environment. Experimental results demonstrate the method can effectively reduce turn-on time at the variation with temperature of working environment.