bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Rock Mass Permeability Based on Geometry Measuring Method in a Gold Mine
Authors: Ma Feng Shan , Zhao Hai Jun , Guo Jie
Published: February 2012

In this paper, a practical technical approach for the evaluation of hydraulic conductivity in complex fractured rock mass is present in a seabed gold mine. According to hydrogeological conditions and characteristics survey in the field, geometry measuring method was applied in the in-situ investigation. Moreover, various methods were involved in the evaluation of the fracture development, water seepage features and permeability of the fractured rock mass. Through this study, a particular set of hydrogeological investigation, research and permeability evaluation methods were put forward, which are of great significance to the research and practical production of mines with similar cases.
Research on Permeability of Coal Samples with and without the Effect of Supercritical CO2
Authors: Yang Tao , Nie Bai Sheng , Yang Dong , Zhang Ru Ming
Published: February 2012

To improve the low-permeability coal seam gas drainage and gas prevention and to seek the methods to improve the permeability of low-permeability coal, the experimental study on supercritical CO2 on coal was conducted in the laboratory conditions, and the experiment on pseudo-triaxial permeability testing for coal samples, with and without supercritical CO2, was conducted. The results show that due to the effect of supercritical CO2 on coal like physi-chemistry, the porosity of coal was changed, which markedly varied the permeability of coal samples before and after the effect of supercritical CO2; the permeability of the experimented coal samples was significantly higher than before, and average permeability increased by nearly an order of magnitude under the same volume-stress.
ADRC Applied in Micro Grid of Wind Turbine with Flywheel
Authors: Zhang Yan Ning , Kang Long Yun , Cao Bing Gang , Xu Jian Ming
Published: February 2012

The auto-disturbance-rejection-controller (ADRC) is a new control theory that doesn’t need the exact object model. The variation of load resistance is observed and estimated by an extended state observer, which is the core of the ADRC. It is known to all that t-he output power of wind turbine is direct ration to the third power of wind speed; hence the flywheel is introduced to keep the stable current output. The system is composed by the permanent magnetism synchronized generator wind turbine and the permanent magnetism synchronized generator flywheel. The control system is nonlinear, the nonlinear parts of the system can be considered as the disturbance which is estimated by an additional state. The Matlab simulink software and lab system have been carried out and the results confirm the robustness of the ADRC.
Formulation of a New Type of Electrolytes for LiNi1/3Co1/3Mn1/3O2 Cathodes Working in an Ultra-Low Temperature Range
Authors: Yang Chun Wei , Ren Yong Huan , Wu Bo Rong , Wu Feng
Published: February 2012

A new type of electrolytes for low temperature operation of Li-ion batteries was formulated in this work. Instead of LiPF6, LiBF4 and LiODFB were used to form this new type of electrolytes, although LiPF6 is the mostly chosen solute in the state-of-the-art Li-ion electrolytes. It was found although a LiBF4-based electrolyte had a lower ionic conductivity than that of a LiODFB-based electrolyte, a LiODFB-based electrolyte demonstrated improved low temperature performance. In particular, at-30°C, a Li-ion cell with 1M LiODFB dissolved in a 1:2:5 (wt.) propylene carbonate (PC)/ethylene carbonate (EC)/ethyl methyl carbonate (EMC) mixed solvent delivered 86% of the capacity obtained at 20°C. Furthermore, the cells with a LiODFB-based electrolyte showed lower polarization at-30°C. The above results suggest that beside the ionic conductivity of an electrolyte as a limitation to the low temperature operation of Li-ion batteries, there was interface impedance having effect on it. Analysis of cell impedance revealed that reduced charge-transfer resistance by using LiODFB resulted in improved low temperature performance of Li-ion batteries.
Numerical Simulation of the Nuclear Main Pump in the Sbloca
Authors: Yu Jian , Tian Fu , Ma Ming , Wang Xiao Fang
Published: February 2012

In this paper, the transient of the flow field of the nuclear main pump has been analyzed in the SBLOCA and the half mass flow rate time is obtained through the simulation. The results of the simulation show that, as nuclear main pump runs down, the mass flow rate and head of the pump drops as well. The blade surface pressure is not evenly distributed. The blade bears the force of the flow. So Pump unit should have sufficient moment of inertia, so that when the reactor in an emergency shuts down caused by the failure of power supply, nucleate burning down can be avoided by cooling the core. On the braking operation condition, the half mass flow rate time required should be guaranteed. Through simulation, we find when the half time is equal to 10s, the half mass flow rate time is about 4.6s Though it is a little shorter than 5s required, the AP1000 model selected basically meet the idle requirement.
Numerical Simulation on Small Scale Straight-Blade and Twisted-Blade Vertical Axis Wind Turbine
Authors: Lv Yong Zhe , Jiang Dong Xiang , Jiang Yong
Published: February 2012

This paper presents an analysis on the performance of vertical axis wind turbine of two types, namely straight-blade vertical axis wind turbine (SB-VAWT) and twisted-blade vertical axis wind turbine (TB-VAWT). An attempt of this simulation is to identify which type performs better in the same wind conditions and swept area. Three-dimensional computational fluid dynamics (CFD) was adopted in this analysis, after solid models of them were generated. Preliminary results of torque, power and aerodynamics in the fluid field were obtained for discussion. Finally, there provided some guidance for future wind tunnel tests.
Numerical Calculation and Simulation on Melting and Solidification Time Periods of a Phase Change Material
Authors: Sun Xiao Qin , Zhang Quan , Liu Ying Jun , Yang Hong Xing , Zhang Lin Feng , Liao Shu Guang
Published: February 2012

Energy storage technology is becoming more important nowadays due to use of renewable energy resources. The heat transfer performance of a PCM (phase change material) which is the carrier of energy is the main factor that affects its utilization. This paper presents the thermal characteristics of the PCM-20. An energy storage module is designed based on the numerical calculation results from the MATLAB. Numerical simulation about this module is carried out by CFD software. The simulation results have been compared with the results of numerical calculation and the error between them has been analyzed and discussed.
Aerodynamic Optimization Design of a Turbocharger Compressor Impeller
Authors: Ji Chun Jun , Li Xiao Qing
Published: February 2012

The flow inside the impeller and diffuser of a turbocharger compressor was analyzed numerically in this paper. The results indicate that the internal flow is disturbed and efficiency is low. There exists a big vortex in the diffuser which dissipates a large amount of energy. Based on the commercial design software, different design parameters were optimized by trial-and-error. Numerical flow analysis results of the final design show that the efficiency is increased by 6.26% and internal flow is improved greatly. It can be concluded that the meridian radius of the impeller flow path has great effect on the compressor performance.
Mechanism Analysis of Jet Drilling Rock by Numerical Simulation and Experiment
Authors: Liao Hua Lin
Published: February 2012

Rock damage and breaking mechanism with water jet has been as yet a difficult problem due to jet high turbulence and complicacy of rock material. According to fluid-structure interaction (FSI) theory, the standard k-epsilon two equations and control volume method for water jet, and the elastic orthotropic continuum and finite element method for rocks, are employed respectively to establish a numerical analyzing model of high pressure water jet impinging on rock. A damage criterion, with non-dimensional coefficient to characterize rock damage, is also set up for analyzing rock failure mechanism with water jet. The process of jet impact on the rock is simulated, by using the FSI model, Micro failure mechanism test and analysis with scanning electron microscope (SEM) for rock failure surface by jets cutting were performed, whose results show that the micro-mechanism of rock failure due to water jet impingement is a brittle fracture in the condition of tensile and shearing stress. The test results also agree well with the numerical simulating analysis, which constructs a bridge between the micro-failure and macro-breaking mechanism of rock with water jets impact. The investigation affords a new method for studying the mechanism of rock failure underhigh pressure water jet impingement.
The Research for the Extraction of Yeast’S Nucleic Acid with [BMIM] BF4-H2O-KH2PO4 Ionic Liquid Aqueous Two-Phase System
Authors: Huang De Juan , Huang De Chao
Published: February 2012

Construct ionic liquid - salt aqueous two-phase system for extracting yeast DNA. By using NaOH solution to process yeast, leaching the nucleic acid by ultrasonic assisting, variety of salts’ aqueous two-phase influence on the ionic liquid 1-butyl-3-methylimidazolium fluoroborate are discussed, and the influence of additive quantity of KH2PO4 and PH on the ionic liquid aqueous two-phase system for extraction of nucleic acid are studied. The result shows that process the yeast with 0.3% NaOH solution, assisted by ultrasound with power of 80W, temperature 60 °C, 3 hours’ extraction. KH2PO4take obvious advantage in the formation of ionic liquid aqueous two-phase system. In the process of extraction nucleic acid from [BMIM] BF4-H2O-KH2PO4aqueous two-phase process of nucleic acid, the best B-R buffer PH is 8.95, when the additive dosage of KH2PO4is 2.000g, A260/A280 in the supernatant is smaller than control group, the substratum which rich in ionic liquid contains more nucleic acid than the supernatant, and A260 in the supernatant is more than that in the control group. Therefore, we conclude that the ionic liquid aqueous two-phase has a relatively good effect in extraction of nucleic.
Comparison of Non-Covalent Interactions between a Series of N-Phosphoryl Dipeptide or Methyl Esters and Cytochrome C by Electrospray Ionization Mass Spectrometry
Authors: Qiang Li Ming , Dong Xu Ru , Lu Ming Xiu , Lu Kui , Zhao Yu Fen , Cao Shu Xia
Published: February 2012

The non-covalent interaction between a series of N-phosphoryl dipeptides (or methyl esters) (DPP) and cytochrome C was studied by ESI-MS. The function of different groups in DPP and binding sites of protein were investigated. The results revealed that hydroxyl and aromatic ring in DPP were both important group for the interaction, and aromatic ring had double functions on the interaction. In addition, the molecular size, flexibility and steric hindrance showed obvious effects on the interaction, while, the chirality, sequence and length of carbon chains (changing 1−2C) of amino acid residue in DPP showed little effects on the interaction under the experimental conditions. The results provide some useful information and theoretical basis for the molecular design of peptide drugs.
Molar Kinetics in Catalytic Hydrocracking of Asphaltenes
Authors: Zhang Sheng Jian , Zhao Ying Xian
Published: February 2012

The hydrocracking of a pentane-insoluble asphaltene over NiMo/γ-Al2O3 was investigated in a microbatch reactor at 703 K. The cracking kinetics of the asphaltene was analyzed on a total molar basis. The first-order kinetics fits the experimental data in reaction times ≤30 min adequately, to give the rate constant of 0.0498 min-1. For reaction times over 30 min, however, secondary reactions such as coke formation could become significant. The formation probability of gas products decreases from the initial value of circa 0.8 to a stable level of 0.6 in 30 min, and the formation probability of liquid products increases from 0.2 to 0.4 accordingly.
Preparation and Properties of Copolymer of Degraded Starch and CA-HPA Initiated by HRP/H2O2/ACAC
Authors: Lv Sheng Hua , Yan Xiao Liang , Wang Fei
Published: February 2012

Citrate-hydroxypropyl acrylate (CA-HPA) was prepared by esterification of citric acid and hydroxypropyl acrylate. Then a graft copolymer was synthesized by copolymerization of degraded starch and CA-HPA using a complex initiation system of horseradish peroxidase (HRP)/H2O2/acetylacetone (ACAC). The effects of amount of CA-HPA, HRP, ACAC and reaction temperature on grafting efficiency (GE) and grafting percentage (GP) were investigated. The results showed that the graft copolymer with higher grafting level could be prepared by grafting copolymerization of 50 g degraded starch (wt 15%) with 13.9 g CA-HPA in the presence of 6.4 mg HRP/4.7mL H2O2/1.2g ACAC at 35 °C for 5h under system pH 8. The graft copolymer can be used as retannage. The structure of the copolymer was characterized by FTIR, and the mechanism of polymerization was advanced. The retanned leather has the merits of good uniformity fullness softness, strong selecting filling properties and good elasticity.
The Synthesized Principle and Property of Several Extraction Agents for Germanium
Authors: Liang Jie , Xu Kai , Fan Li Jun , Huang Yan
Published: February 2012

There is an introduction of the synthesis principles and extraction performance of several kinds of germanium extraction agents including Lix63, Kelex100, and 7815. In addition, the general procedures and technical advantages of the extraction agents for germanium recycling are analyzed and compared. Finally, recommendations for the synthesis of a new generation of germanium extraction agent are proposed.
Preparation of ZrO2 Composite Ceramics with High Thermal Shock Resistance
Authors: Ge He Yi , Liu Jian Ye , Hou Xian Qin , Wang Dong Zhi
Published: February 2012

The physical and mechanical properties of nanometer ZrO2-ZrO2fiber composite ceramics were studied by introduction of ZrO2fiber. ZrO2composite ceramics at different sintering temperature was investigated by porosity and water absorption measurements, flexual strength and thermal shock resistance analysis. Results showed that ZrO2composite ceramics containing 15 wt% ZrO2fiber with sintering temperature of 1650°C exhibited good mechanical properties and thermal shock resistance. The porosity and the water absorption were 8.84% and 1.62%, respectively. The flexual strength was 975 MPa and the thermal shock times reached 31 times. Scanning electron microscope (SEM) was used to analyze the microstructure of ZrO2composite ceramics.
Efficient Synthesis of Thieno [2,3-d] Pyrimidin-4(4H)-ones by the Aza-Wittig Methodology
Authors: Chen Hong , Yan Kai , Liu Ming Guo
Published: February 2012

The carbodiimides 4, obtained from the aza-Wittig reaction of iminophosphorane 3 with aromatic isocyanates, reacted with aliphatic amines or alcohols to give 2-substituted thieno [2,3-d] pyrimidin-4(4H)-ones 6 in the presence of catalytic amount of sodium alkoxide in good yields.
Purification of Polyether Polyols Made by Double Metal Cyanide Catalysis
Authors: Ma Wei Hua , Yang Liu , Zhong Qin
Published: February 2012

Purification of polyether polyols made by double metal cyanide catalysis was studied. The removal effect of residual double metal cyanide in the polyols by the methods of adsorption and precipitation-filtration is characterized by the residual concentration of the zinc and cobalt ions which is measured by Inductively Coupled Plasma Atomic Emission Spectrometry. Compared with precipitation-filtration, the method of adsorption was more practical and efficient for the purification of the polyols. And the optimum kind and amount of the adsorbent were obtained. The results showed that the combination of chelating fiber and attapulgus clay was the most favorable for the removal of zinc and cobalt ions and the appropriate weight ratio of chelating fiber and attapulgus clay was 1:1. The total concentration of zinc and cobalt ions can be reduced to lower than 1×10-6. And the amount of the adsorbent added was 3.33% by the weight of the polyether polyols. Also through Scanning Electron Spectroscopy the morphology of the chelating fiber was characterized before and after adsorption. The functional groups on the surface of the fiber could be coordinated with the catalyst attached to the polyol polymer chains to form the separable insoluble particles.
Preparation and Electrochemical Investigation of LiCoPO4 Cathode Material for Lithium Ion Batteries
Authors: Wang Shao Liang , Tang Zhi Yuan , Sha Ou , Yan Ji , Ma Li
Published: February 2012

LiCoPO4 was prepared by a citric acid assisted sol-gel method and exploited as cathode material for lithium ion batteries. TG curve showed the appropriate temperature of the reaction and X-ray diffraction patterns indicated that LiCoPO4 synthesized at different temperatures was crystallized in an orthorhombic structure. During charge-discharge cycles, LiCoPO4 presented a plateaus of 4.8V corresponding to Co3+/Co2+ redox couples, and a discharge capacity of 126.3 mAh/g in the ﬁrst cycle. The CV curve of LiCoPO4 showed that Li-ion diffusion in LiCoPO4 obeyed a different mechanism between charge and discharge processes.
Three-Dimensional Open-Framework Zinc Phosphite: Synthesis and Characterization
Authors: Chen Rui Xin , Xu Ling Yan , Sun Chang Feng
Published: February 2012

Generally, open-framework metal phosphites like phosphates, are synthesized under hydrothermal or solvothermal conditions in the presence of organic amines, which may act as structure-directing agent or template to avoid the formation of dense phase, but few of them has been successfully prepared at room temperature which seems to be difficult to synthesize these compounds. In this work, at room temperature, employing n-propylamine as a template, a three-dimensional zinc phosphite (C3H10N) 2·[Zn3(HPO3)4] has been prepared and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, powder X-ray diffraction, and thermogravimetric analysis. The compound crystallizes in the orthorhombic space group Pccn, with cell parameters, a = 9.839(3) Å, b = 23.356(8) Å, c = 8.970(3) Å, V = 2050.2(8) nm3 and Z = 4.
Solvent-Free Synthesis and Characterization of the Zn(II) Complexes with Amino Acid Schiff Base
Authors: Zhong W. , Zhong Guo Qing , Zhang Y. , Zhong Q.
Published: February 2012

Three zinc (II) complexes of the amino acid Schiff base were synthesized by the one step reaction of amino acid with aldehyde, zinc acetate in solvent-free. The compositions and structures of the complexes were characterized by elemental analyses, FTIR, XRD, TG-DSC. The compositions of the complexes are ZnL•nH2O (L = sal-leu, sal-ala, van-leu; sal = salicylaldehyde; van = vanillic aldehyde; leu = leucine; ala = alanine). Infrared spectra of the complexes indicate that the Schiff base ligands are formed, zinc ion is coordinated to the Schiff base ligands as terdentate with O, O and N donors from carboxylic, phenolic and imino groups respectively, the coordination numbers of zinc ion is four. The possible pyrolysis reactions in the thermal decomposition process of the complexes, the experimental and calculated percentage mass loss are also given.
The Experiment Study on the Void Fraction in PPG Solution
Authors: Chen Qian Qiao , Zhong Qin , Qi Li , Cheng Qun Qun , Wang Lu , Hu Miao
Published: February 2012

Using the three-layer impellers with big size diameter in an unbaffled elliptic bottom stirred tank，the gas holdup (ε) was studied in the systems of air-polyether polyol (PPG). The results indicate that the gas holdup in the air-PPG system is higher, it increase with the superficial gas phase velocity (Vs) and specific power input (Pm) increase, and decrease as the temperature increase. The influence is severely when the temperature is below 100°C, and is weak above 100 °C.The conclusions give reference for choosing the operation parameter and designing and scale-up of PPG polymerization reactor.
Research on Solvent Extraction Process of Coal for Direct Carbon Fuel Cells
Authors: Bi Wen Yan , Yang Hong , Miao Juan , Zhang Yu Gui , Wan Jian Feng
Published: February 2012

Two different extraction methods, microwave extraction and traditional soxhlet extraction, were used to evaluate the optimal extraction process of coal for direct carbon fuel cells through enrichment efficiency of the organic components and extraction time required under the same extraction rate. The experimental results showed that the extraction rate of microwave extraction was 9.7368% when adopted tectonic coal of 8th coal mine as sample, selected 80mL pyridine as solvent, set 95W as microwave power and 3min as extraction time. Under the same extraction rate condition, soxhlet extraction time is 35.73h, and the extraction efficiency of the microwave extraction was 714.6 times that of the soxhlet extraction. The microwave extraction was a simplify and promising working for coal, which was used as raw fuel for direct carbon fuel cells, with fast extraction speed, large sample capacity, energy saving and environmental friendly.
Preparation of Soluble Chitosan by Mechnochemistry Process
Authors: Xu Zhi , Fei Qing Zhi
Published: February 2012

The active technology of the mechnochemistry process is studied. Structure of chitin during this process is characterized by infrared spectroscopy (IR) and scanning electron microscopy (SEM). Different mechanical activating time and size of shrimp shell have effects on solubility, which have been examined respectively. The results indicate that the mechanical-chemical process cause remarkable impact on changing molecular structure, among which stirring time、quantity of shrimp shell ground at a time are the most obvious phenomenon effecting water-solubility of chitosan. The crystal structure of chitin in shrimp shell is destroyed in mechanical-chemical process and changed from chitin to chitosan in a short time, taken off the acetyl group.
Preparation and Characrization of Tic/C Composite Fiber by Chemical Vapor Deposition
Authors: Wang Hai Quan
Published: February 2012

- TiC/C composite fibers were prepared by vapor phase titanizing of the regular carbon fibers via chemical vapor deposition (CVD). The carbon fibers were titanized from the surface of the fiber to the core. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were applied to characterize the morphology and structure of the TiC/C composite fibers. The influences of CVD reaction conditions such as temperature and reaction time on the TiC particle size and the thickness of the deposited layer were investigated. Higher temperature and longer time resulted in the growth of bigger size of the TiC crystal particles, and the particle uniformity was also decreased.
Adsorption of Phthalate Esters from Aqueous Solution by Mg–Al Layered Double Hydroxide
Authors: Wang Long , Gao Xu , Guo Jin Song , Zhang Wen , Xu Yang
Published: February 2012

Mg–Al layered double hydroxide (Mg–Al LDH) was investigated for adsorption of dimethyl phthalate (DMP), di-(2-ethylhexyl) phthalate (DEHP) and dioctyl phthalate (DOP) from water samples. The adsorption capability of the Mg–Al LDH was compared with that of activated carbon. Adsorption of the three phthalate esters (PAEs) fitted pseudo-second-order kinetics, and the Langmuir or Freundlich equations described the adsorption isotherms. Adsorption of the PAEs was exothermic, and was mainly dominated by physical interactions including dispersion, induction, orientation and hydrogen bond forces. Compared with activated carbon, the Mg–Al LDH removal efficiency of the relatively small PAE, DMP, was about 20 % lower. The removal efficiencies of the larger PAEs, DEHP and DOP, were about the same on both sorbents. After three regeneration cycles of the Mg–Al LDH at 300 °C for 2 h, its adsorption capacity remained above 90 %. The infrared (IR) spectra and the X-ray diffraction (XRD) patterns for the Mg-Al-LDH before and after regeneration showed no large differences, which indicates that the structure of the Mg–Al LDH does not change after regeneration.
Enhancement of Absorption of Injected Gas in New Type Mechanical Stirring Injection Refine Equipment
Authors: Zhang Ting An , Liu Yan , Wang Qiang , He Ji Cheng , Masamichi Sano
Published: February 2012

The bubble disintegration is of great scientific importance in metal refining, In order for further improvement, Research on bubble disintegration and dispersion becomes necessary, The intensification of bubble disintegration experiment that we have done in cold water model by study absorption rate ,The purpose is to research bubble disintegration under difference experimental condition . In this paper, we use mass transfer coefficients stand for absorption rate, we also study utilization rate, we want to research the best experimental condition which can enhance mass transfer coefficients and utilization rate. On the basis of experimental result, Provided a scientific and experimental basis to high-temperature experiment of bubble dispersion and disintegration .Experimental results show:the rate of absorption of CO2 injected in aqueous NaOH solution can be increased greatly by mechanical stirring when the positive-reverse rotation mode is adopted. Dispersion of small bubbles in the liquid is very effective for increasing the absorption rate.
An Improved Block 2DPCA Face Recognition Algorithm with L1-Norm
Authors: Zheng Hao , Pan Lei
Published: February 2012

Most of the existing Block 2DPCA algorithms are based on Frobenius norm, which makes them sensitive to outliers. In this paper, we propose a new improved Block 2DPCA algorithm with L1-norm, which is robust to outliers. The experimental results of FERET face database indicated that the recognition performance of new algorithm is superior to Block 2DPCA, more robust than Block 2DPCA.
Non-Autonomous Wheeled Mobile Robot Trajectory Tracking Control Based on the Navigation via WSN
Authors: Lu Da Yong , Luo Zhen Hua , Tian Jian Lu
Published: February 2012

Trajectory tracking control is a major control problem in the application of the wheeled mobile robots (WMRs). However, many of the WMRs are autonomous which are equipped with several kinds of sensor to detect the position and orientation by itself, such as ultrasonic, laser, infrared and visual. This paper studies the implementation for a distributed network feedback control system and the trajectory tracking control algorithm for a non-autonomous WMR. The control system consists of a wireless sensor network (WSN) and a monitoring base station for measurement and feedback, and a non-autonomous WMR as controlled plant. To cope with the distributed and asynchronous measurements and slow response of the feedback channel, the sectional error amplitude limited algorithm is studied and the results show the system can effectively track a reference trajectory.
Digitally Assisted Backend Correction Pipeline ADC Verilog-A Modeling
Authors: Gong Yue Hong , Luo Min , Ma Jian Guo
Published: February 2012

In this paper, a 12 bits pipeline ADC (analog to digital converter) based on digitally assisted backend correction is described and behaviorally modeled in Verilog-A language. The Verilog-A model is simulated with Cadence Spectre simulator. In the traditional use of pipeline ADC, the for-end sample and hold amplifier occupies the most power consumption. To decreases the system power consumption, open-loop amplifier is used in the first residual amplify circuit between first and second stage sub-ADC. To correct the nonlinear error introduced by the open-loop amplifier, backend digitally correction is applied.
Stress and Adhesion Determination of a Wedged Iron Film System by Buckle Morphologies
Authors: Zhou Hong , Yu Sen Jiang , Zhang Yong Ju , Chen Miao Gen
Published: February 2012

By using the mobile property of silicone oil, a wedged iron (Fe) film system, deposited on glass substrate, has been prepared by dc-magnetron sputtering technique. The wedged Fe film is quenched by the silicone oil during deposition, and therefore contains a very high compressive stress, which is relieved by formation of a large number of telephone cord buckles. Both the buckle width l and maximum buckle deflection δ increase linearly with the film thickness, but the ratio of δ to l (l/δ ) decreases steadily. The internal stress and adhesion energy are estimated in the frame of continuum elastic theory.
Structured Design and Residual Stress for Ni/Ni3Al Multi-Layered Sheet
Authors: Xiao Yong Dong , Hu Zhao Hui , Gao Hong Cheng , Li Ji Min
Published: February 2012

The residual stress and the effect of microstructure prameters on failure performance of Ni/Ni3Al multi-layered sheet were studied by Correlative theory and FE method. The results showed that the fracture work increases gradually with the increasing of layer number or thickness ratio. However, the rising extent reduced gradually and when the two parameters exceeded a certain value, the fracture work would not be changed. The value of residual stress reached its maximum at the centre and reached its minimum at the edge of multi-layered sheet. Residual stress in Ni layers and Ni3Al layers was compressive stress and tension stress respectively. With increasing of layer number or thickness ratio, compressive stress would rise gradually and compressive stress would reduce gradually.
POMM: Precise Overpass Map-Matching Model and Algorithm
Authors: Zhu Zhen Xing , Xing Jian Ping , Wang De Qiang
Published: February 2012

Current map-matching algorithms consider more about the common plain road networks. The overpass always be ignored or treated as normal intersection without considering its complex topological structure. In order to fill this gap in map-matching area, the POMM (Precise Overpass Map-matching Model and Algorithm) is proposed in this paper. A novel overpass model is built for the overpasses map-matching algorithm. This model divided the overpass into straight roads and curve ones which consist of a set of directional points. According to the match degree for each straight road or directional point, the optimum road can be selectd from the candidate roads. Finally, the vehicle can be matched to the actual position on the optimum road. Experiment results of Jinan Bayi overpass using the actual GPS data shows that the algorithm has efficiency in accuracy (over 95%) and can precisely find the actual position of the vehicle in the overpass road, especially for the curve roads.
Discernibility Matrix-Based Attribute Reduction Algorithm of Decision Table
Authors: He Ying , He Dan
Published: February 2012

A discernibility matrix-based attribute reduction algorithm of decision table is introduced in this paper, which takes the importance of attributes as the heuristic message. This method solves the problem of the attribute selection when the frequencies of decision table attributes are equal. The result shows that this method can give out simple but effective method of attribute reduction.
Optical Properties of Near-Infrared Cyanine Dye Molecules Adsorbed on Silver Nanoparticles
Authors: Meng Tao , Zhang Chun Mei , Li Mi Dan , Liu Chun , Meng Shan Shan
Published: February 2012

The optical property of near-infrared cyanine dye adsorbed on silver nanopaticals has been studied by means of UV-Vis spectrophotometer. The adsorption of near-IR cyanine dye on silver nanopaticles was highly dependent on the concentration of silver nanoparticles. As a result, in the UV-Vis spectra, it was shown that the “red-shift”, as silver nanoparticles size, increased and the “blue-shift”, as concentration of silver nanoparticle increased as well. The adsorbed spectral peaks of near-infrared cyanine dye disappeared as concentration of silver nanoparticles increased.
Vibration Control of a Flexible Beam Using Model Predictive Control
Authors: Hu Jun Feng , Zhu Da Chang , Chen Qiang
Published: February 2012

Model predictive control is applied to suppress the vibration of a flexible link with piezoelectric actuators and strain gage transducer. The state-space dynamic model of the system was derived by using finite element method and experimental modal test. On the basis of the model, model predictive controller is designed taking into account the uncertain disturbance and measurement noise. The discrete prediction model is derived from the state-space equation of the system, and the future output is obtained from the model. The uncertain external disturbance and measurement noise are white noise signal, the Kalman filter estimator is designed to estimate the state variables of the system. A standard quadratic programming optimization problem is formed where the performance index function minimizes a quadratic performance function that trades off controller performance and control effort. The constraints are the control input voltage and its change rate. Finally, the optimization problem is solved to obtain the optimal control output. A MIMO control system is built using dSPACE DS1103 platform, and experimental tests are performed. The performances of the controller are verified experimentally. The results of experiment show the effectiveness of the controller.
Analysis of Motion in Longitudinal Plane of Negative Buoyancy Vehicle
Authors: Yan Hui , Ge Tong , Liu Jian Min
Published: February 2012

This article described a novel type of autonomous underwater vehicle and modeled the dynamics. This kind of vehicle looked like an air-plane with large wings and worked under the condition of negative buoyancy. The motions of negative-buoyancy-vehicle (NBV) in the longitudinal plane were analyzed through linear system theory. This paper divided motion of NBV into a few modes in the longitudinal plane and provided a method of reduction of order to simplify the analysis, as well as gave the criterion of static stability under constant load in longitudinal plane. It had been found that the maneuverability and stability of NBV was related to many factors such as the velocity, lift-drag ratio, buoyancy and metacentric height. All of the conclusions could be applied on NBV design.
The Design Method of Optimum Field-Plate Structure for HEMTs
Authors: Zhou Wei , Wu Jie , Li Xiang , Yang Jie , Xia Su Jing , Wu Tang
Published: February 2012

This paper investigated on the optimization design of the AlGaN/GaN High electron mobility transistors (HEMT) with gate terminal field-plate (FPs) structure and proposed an optimization method at a given work conditions, such as drain bias Vd . Though the simulation, we obtain two fitting formula about the FPs thickness tox and the minimum length lmin.
A Strong Forward-Secure Proxy Blind Signature Scheme
Authors: Zhang Long , Lu Shu Yi
Published: February 2012

Combining the mechanism of the hash chain with the forward-secure proxy blind signature, we firstly propose a new strong forward-secure proxy blind signature scheme. This scheme has many secure characters, such as strong forward security, namely, although the attacker get the key in some period , the attacker cannot forge the signature in the past and future periods, verifiability, unforgeability, distinguishability, identifiability, strong blindness.
Spectral Prediction Model for Halftone Prints by Enhanced Clapper-Yule Model
Authors: Meng Tao , Zhang Chun Mei , Li Mi Dan , Song Yi Xiao , Sun Tai , Chen Cai
Published: February 2012

The classical Clapper-Yule model and its improved models will both introduced the extended application which supports rough printing and halftone color fluorescent imaging. The characteristics of the new model were analyzed and the prospect of the Clapper-Yule mode was discussed. We proposed a new model, which was an enhancement of the classical Clapper-Yule model, which simulate optical dot gain of halftone prints by taking into account lateral scattering within the paper bulk and multiple internal reflections. The model we propose also takes into account the reflectance of inks at surface of the specific colors at specific rates. The model opens the way towards color separation of images to be reproduced. Several designs printed on an offset press demonstrate their applicability and their benefits.
Spectrum Trade Model Based on Voronoi Diagram
Authors: Liu Li Xia , Hu Gang , Huang Zhen , Peng Yu Xing
Published: February 2012

In wireless cognitive networks the secondary users (SU, the unlicensed user) can share the spectrum via opportunistic access and spectrum trade. The former can’t offer the reliable and steady communication, while the latter can. It is a hot topic how the primary users (PU, the licensed user) provide the resources to SUs. We propose a novel spectrum trade model based on the Voronoi diagram: V-STM, which can promise fairness and rationality of spectrum lease. We also analyze the effect of communication range and price on spectrum trade. Simulation results demonstrate the performance of the proposed model in terms of the fairness of users and the whole profit of the network.
Research Progress of Structural Seismic Design Thought
Authors: Hao Ting Yue
Published: February 2012

Research progress of structural seismic design theory is analyzed and collated in this paper, including static analysis theory, theory of response spectrum, dynamic theory. The three theoretical research and design methods are analyzed and described in the paper one by one. At last, modern seismic design method which is called performance-based seismic design theory is compared and analyzed with the traditional anti-seismic design theory. Its advanced characteristics and advantages are obtained, which will be the core and development of seismic design ideas.
A Differential Capacitive Accelerometer with Four Folded Springs and Changeable Area
Authors: Dong Wei , Zhou Jing Ran , Guo Wen Bin , Zhang Xin Dong , Liu Cai Xia , Shen Liang , Ruan Sheng Ping , Chen Wei You
Published: February 2012

A differential capacitive accelerometer with four folded springs and changeable area was designed and fabricated. It was composed of upper electrode(proof mass), four folded springs、lower comb electrode. Modal and statics were analyzed by ANSYS, accelerometer was fabricated by bond and ICP etching technology. Detection circuit was fabricated and the test was completed. The maximum measured acceleration is 12g, sensitivity is 86mV/g, and precision is higher than ±4.5%.
Speech Enhancement Method under Low SNR
Authors: Cai Wen Long , Ma Guang
Published: February 2012

In this document, the pitch period is detected according to the sensitivity to weak sinusoidal signal and strong immunity ability to noise of Duffing oscillator, at the background of strong noise. And then enhancing pitch obtained by harmonic method. The test results show that the enhancing effect of this method is obvious under low SNR condition, and speech distortion is small.
Modal Analysis of Mast Section of Hoist Based on the Vibration Theory
Authors: Luo Ji Man , Jiang Yang , Xing Zhi Hui
Published: February 2012

Vibration is one of problems of mechanical structures, because structural resonance or fatigue will be caused by the vibration, thus it will be cause the damage of structure. In order to avoid the damage of structure, it is necessary to analyze the stiffness characteristics of the structure，which is the natural frequency and vibration mode figure, therefore unnecessary loss because of the resonance causes can be effectively avoided. By using modal analysis method which is in the structural dynamics, vibration pattern of structure system can be visually obtained from theoretical calculation and ANSYS simulation. The first 6 order natural frequencies of different working conditions have been calculated in this paper, dynamic displacement formula in external excitation have been shown when the cage move to a different location. Vibration mode figure of structure system can be drawn corresponding to the first 6 order natural frequencies, based on the finite element analysis software ANSYS, vibration image of structure system have been simulated corresponding to the first 6 order natural frequencies. The dynamic characteristics of structure system are affected when the cage to a different location. Through the cage to a different location, external excitation force have a great influence on the top of the free end, in the actual construction, the top free ends connected tie-in device stiffness should be strengthened, the system stability will be improved.
Analysis of Hydrogen Content in Hydride Film by Elastic Recoil Method
Authors: Liu Chao Zhuo
Published: February 2012

The essential principle of elastic recoil detection analysis (ERDA) of hydrogen content in the film and the experimental method were described briefly. The energy spectrum of the recoiled hydrogen atom can be obtained by the elastic collision of incident ion beam with hydrogen atoms in film, and the spectrum can be transferred easily into hydrogen concentration and depth profile. For illustrating the application of ERDA in hydrogen storage research, a beam of helium ion was used to recoil hydrogen in titanium hydride and deuteride film to obtain hydrogen contents and depth profiles. This technique was believed to be powerful in determining hydrogen content in hydride films.
Preparation and Electromagnetic Wave Absorption Properties of Carbon Nanotubes-Titanium Dioxide Nanoparticles
Authors: Wang Xin Jun , Wang Fang , Gao Chen , Sun Dong Shan
Published: February 2012

A novel titanium dioxide （TiO2） nanoparticles coated carbon nanotubes (CNTs) composites were prepared by sol-gel method as microwave absorbing materials in this paper. SEM and XRD researches show that sol-gel method can realize uniform coating of CNTs with TiO2. Among them, with the weight fraction of TiO2/ CNTs composites was 10%, microwave absorption characteristics with a minimum RL value of -34 dB at 6.2 GHz on a coating with a matching thickness of 4mm and <−10 dB was obtained in the frequency range of 4.5-18 GHz with the thickness of 1.5-5.0mm.
Dynamic Modeling and Simulation of Stratospheric Airships
Authors: Hu Guo Chang , Wu Mei Ping
Published: February 2012

Aiming at the requirements of autonomous control for stratospheric airships, based on description of the modeling plant and forces analysis in detail, the dynamic model is established by Newton Method. The motion characteristics of airships under control action are analyzed using simulation method. Simulation results indicate the correctness of dynamic model, and can make itself a theoretical basis for the overall design of the stratospheric airship.
The Progress in Aluminum Foam Research in China
Authors: Yao Guang Chun , Liu Huan , Song Bin Na
Published: February 2012

The aluminum foam materials have studied for the last 15 years in China, from laboratory experiments to industrialized scale. we can manufacture 800mm×2000mm aluminum foam board products. The essential parameters of our aluminum foam product are as follows, density: 0.3~0.6g/cm3; porosity: 77%~88%; pore diameter 5MPa. Some properties of aluminium foam materials were studied such as sound absorption, energy absorption, impact bending strength of aluminum (steel) plate/Al foam sandwich, etc.
A CuZnAl-Based Hybrid Material for the Direct Synthesis of Dimethyl Ether from Syngas
Authors: Li Zhuo , Yang Cheng , Li Jian Qing , Wu Jin Hu
Published: February 2012

A CuZnAl-based hybrid material was prepared by co-precipitation impregnation method using the active components of methanol synthesis material and pseudo-boehmite as the precursors. The as-prepared material was evaluated for the direct synthesis of dimethyl ether (DME) from syngas in a pressurized continuous flow fixed-bed reactor system. It was revealed that the hybrid material showed high activity and selectivity after an induced period, i.e. the CO conversion and DME selectivity reached as high as 81% and 67%, respectively. Moreover, it was observed that there was only slight carbon which could be eliminated rather than graphite carbon deposited on the material after run for 150 h, indicating its good stability for the direct synthesis process .
Towards Fabrication of Low-Cost Carbon/Ceramics Membranes: Substrate Modification
Authors: Wang Chan , Huang Yan
Published: February 2012

This paper presents a novel method for fabrication of carbon membranes for gas separation by mean of surface modification with a conventional 2B pencil on the low-cost macroporous Al2O3 substrate. The resulting membrane was characterized by SEM, which shows that the modified membrane is continuous and uniform without defects. Gas permeation experiments were conducted by single gas measurements (test gas: H2, CO2, O2 and N2) at 20–80 °C under 100–400 kPa. The results show that the pencil lead layer can effectively prevent deep infiltration of precursor solution into the pores of substrate, and that gas transport through carbon membrane follows the molecular sieving mechanism. Based on the modified substrate, the carbon membrane exhibits good permeability (up to the order magnitude of 10-9 mol/m2 s Pa) and separation capability such as H2/N2 of 37.3, CO2/N2 of 11.2, and O2/N2 of 8.3.
Research on Existences and Concept System of Reversal Symmetry in Mechanical Systems
Authors: Ma Zhi Yong
Published: February 2012

Reversal symmetry is one kind of mechanical static structure symmetry, grouped by rotation symmetry and mirror symmetry, widely exists in structures of mechanical products. On the basis of research on the concept systems of rotation symmetry and mirror symmetry and based on analysis of a lot of instances, the concept system of reversal symmetry was established by taking the independence of symmetry components, the directivity of symmetry components, the rotary type of symmetry components and the dimensionality of symmetry components as standards. Accurate instances were particularized to explaining and verifying the concept system. The further research of the application laws of reversal symmetry can benefit from this research result.
Gypsum Dehydration to Alpha-Gypsum in Mixed Chloride Solutions
Authors: Dvořák Karel , Fridrichová Marcela , Gazdič Dominik
Published: February 2012

Brno University of Technology solves in the long term the problem of alpha gypsum preparation by dehydrating the gypsum in the solution of chloride salts. This study verified that alpha-gypsum can be trouble free prepared by gypsum dehydration in solution of a number chloride salts, among others CaCl2, MgCl2 or NaCl. In the same time it was found that owing to the different electro-chemical behavior of Potassium ions, the by heat conditioned reaction of gypsum with the KCl solution the dehydration doesn’t take place, but a partial substitution of Potassium ions by Calcium ions takes place. The product of this reaction is the mineral görgeyit, K2SO4.5CaSO4.H2O.This important problem was solved by reduction of the extremely electro-chemical high mobility of Potassium ions by the method of the mixed chloride solution with Potassium and Sodium ions, the mobility of which is in comparison with the preceding only one third. Samples of hemihydrate in the solution of mixed salts were prepared and tested in conclusion of the research.
Study on Crack Tip Field of Shape Memory Alloy Board under Bending Load
Authors: Zhou Bo , Yin Tai Yue , Li Xu Kun
Published: February 2012

This paper focuses on the thermo-mechanical behaviors of shape memory alloy (SMA) board with a crack subjected to bending load. The stress field near the crack tip of SMA board is described according to the solution of linear elastic mechanics. The phase transformation behaviors of SMA board are formulated based on Zhou’s one-dimensional phase transformation model. The phase transformation zone equation is derived to describe the phase transformation zone near the crack tip.