bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the Effect of Process Parameters on Surface Roughness in Wire EDM of Titanium Alloy
Authors: Garg Mohinder Pal , Jain Ajai , Bhushan Gian
Published: February 2012

This paper investigates the Wire Electric Discharge Machining of Titanium alloy 6-2-4-2.Eight process parameters namely pulse-on time, pulse-off time, peak current, spark gap set voltage, wire feed, wire tension, water pressure, pulse peak voltage and servo feed are varied to study their effect on surface roughness and wire breakage. The experiments are conducted using one-factor-at-a-time approach. Moreover, a few random experiments are also carried to study the phenomenon of wire breakage precisely. The study revealed that surface roughness is directly affected by the pulse-on time, pulse-off time, peak- current, spark gap set voltage and wire tension. Wire feed, Water pressure and pulse peak voltage have negligible effect on the surface roughness. Moreover, wire breakage is predominantly dictated by all the parameters except peak current and pulse peak voltage. An optimum range of input parameters has been bracketed as the final outcome for cutting in terms of surface roughness and to minimize the wire breakage frequency.
Formability Predictions of Deep Drawing Process for Aluminum Alloy A1100-O Sheets by Using Combination FEM with ANN
Authors: Nguyen Duc Toan , Kim Young Suk , Jung Dong Won
Published: February 2012

The FEM simulation results of deep drawing process are carried out to create training cases for the artificial neural network (ANN), and then the well-trained ANN(s) is used to predict the formability of aluminum alloy A1100-O sheets. The OYANE’ s ductile fracture criterion equation [J. Mech. Work. Technol. 4 (1980), pp. 65-81] was implemented to predict the formability of deep drawing process. This ductile fracture criterion is introduced and evaluated from the histories of stress and strain calculated by means of finite element analysis in order to get the ductile fracture value (I). The resolution of the results of ductile fracture criterion equations is carried out via a VUMAT user material, using ABAQUS/Explicit finite element code. From the calculative results of FEM simulation with the changing of various parameters, the formability predictions using ANN methodology was investigated by comparing with random case studies of FEM results and shown good agreements
Statistical Analysis of the Roundness Error Data
Authors: Dong Zhao Peng , Huang Li Ling , Xie Hai Ting , Huang Fu Gui
Published: February 2012

In order to simulate the actual roundness measurement accurately, must find the mathematical model of the actual roundness data, the paper’s main emphasis is doing statistical analysis by plenty of measurement data of roundness, using mathematical knowledge to prove that the actual characteristics of roundness parameters obey the normal distribution, and providing the basis for subsequent computer simulation in the future
Design of New Small Hydroelectric Device
Authors: Zhang Li Zhen , Cao Xiao Long , Li Jun Tao , Wu Shu Lei
Published: February 2012

The paper designed a new small hydroelectric device after analyzing the technological characteristics and the deficiency of the existing hydropower. As a supplement of conventional power, the device can be used in the places that have no conditions to build dams but have a lot of water resource. The new device working principle was introduced and the analysis of its force and motion was made. The design scheme is proved feasibility through theoretical analysis. The model test indicates that this new hydroelectric device has high efficiency.
Investigation of the Microgeometry after Hard Turning and Diamond Burnishing
Authors: Líska Katalin , Kodácsy János , Líska János
Published: February 2012

Paper deals with research of optimal technological parameters at burnishing after hard turning. Burnishing is a less known method, when we machine the surface of workpiece with a harder tool, without chip. Experiments focus on the microgeometrical properties of workpiece, at variation of feed and burnishing force. We measured also machining force at hard turning. Workpiece was from material steel bearing, with signal 100Cr6k and hardeness HRC64.
Development and Application of Multi-Modular Roll Magnetic Separator
Authors: Huang Ding Guo , Liu Song , Jiao Hong Guang , Wang Fei Yue
Published: February 2012

This new dry magnetic separator has a special structure. It has many magnetic roll which are staggered like a stairsteps. It can finish the task of separating different minerals with only this one machine. And also it can make the different magnetic material which are in the same mineral separate at the same time. The permanent magnet system is made of large fan-shaped magnet. The magnet pole N and S are staggered and has perfect performance of magnetic separation. And the magnetic force is made full use by going-up dynamic separation. And also it gives an analysis of stress in the magnetic field. It also shows that its separation idex is better, the economic benefits are obvious, and it has broader prospects of popularization and application.
Study on the Electric Processing Characteristics of Difficult-to-Cut Materials
Authors: Peng Hai , Zhang Qian Yao
Published: February 2012

This paper analyzes the mechanism of EDM and the machining characteristics of difficult-to-cut materials. Analyzes the EDM parameter selection and the influences from electric parameters to electrode wear and processing speed in EDM. Through the test of electric machining difficult-to-cut materials, the degree of influence that electric parameters to electrode wear, processing speed and processing quality are analyzed. Titanium and stainless steel materials are processed by high-current power. After the processing, analysis and study are carried out on the metallographic structure and mechanical properties of these materials. The test result is satisfactory.
Frequency Conversion Timing to Adjust the Centrifugal Pump Flows
Authors: Cheng Guang Zhen , Lin Hong Fei , Dai Ying Jun
Published: February 2012

This document introduce commonly used to control the centrifugal water pump flow, The valve export opens degree, control pump turning speed , working principle and characteristics of the Two kinds methods, the structure of the three-phase Frequency Conversion, the Frequency Conversion external connection, point out the effect that frequency conversion timing to Adjust the flow of the pump.
Study of Electronic and Optical Properties of PbS
Authors: Du Jin Ju , Li Wei
Published: February 2012

The electronic and optical properties of the lead sulfide are studied using first-principles calculations. The energy band structure and density of state of PbS are calculated. The results suggest that PbS exhibit a narrow band gap. The Mulliken analysis shows that the Pb-S bond is ionic. The dielectric function, absorption coefficient, reflectivity spectrum, refractive index and extinction coefficient are calculated for radiation up to 35eV. We have show that S (3p) electrons states and Pb (6p) electrons states play an important role in these transitions.
Torsion-Impedance in Soft Magnetic Amorphous and Nanocrystalline Wires
Authors: Wang Jian Yong , Li Yin Feng , An Lan Zhu , Feng Su Qin , Wang Cheng Lin , Zhao Xi Mei
Published: February 2012

The measurements of magneto-impedance,, have been performed, at the frequency f = 1 MHz, on amorphous and nanocrystalline wires under the application of torsion stress ( = 0-125 rad/m). At , exhibit single-peak due to the axial easy direction of the wires. The torsion-impedance,, is defined as the impedance change with at the condition of the axial field H = 0. We found that at the low torsion , shows a maximum at = 0.87 and 5.23 rad/m for the amorphous and the nanocrystalline samples, respectively; with increasing ,of the amorphous wire decreases monotonously and tends to the saturation, but of the nanocrystalline sample shows two more peaks at = 70.65 and 104.67rad/m. These results have been discussed considering the modification of domain structure by the applied torsion.
Influence of Overburning on Microstructure and Property of 6061 Aluminum Alloy
Authors: Zhang Shi Xing , Qu Shao Min
Published: February 2012

Process of solution treatment of 6061 aluminum alloy was done by hardness test and microanalysis in this paper. The effects of different solution treatment temperature on the microstructure and mechanical properties of 6061 aluminum alloy were studied and the influence of overburning on the microstructure and mechanical properties of 6061 aluminum alloy were also analyzed. The experimental results show that overburning occurring while 6061 aluminum alloy is heated above 580°C . The hardness measurements and microstructure analysis results show that the hardness decreased, grain boundary becomes trigemanal and compounded –melting structure (burnt structure) appeared when overburning occuring for this alloy .
Dynamic Simulations of Rehabilitation Move-Assistant Device Based on Adams
Authors: Zhang Wan Gong , Wu Hai Tao , Liu Hong Bin
Published: February 2012

The authors established a rehabilitation move-assistant device in SolidWorks, and then imported the model into Adams to create a simulation model via the interface between them. Adams run dynamic simulations of the model under different load outputting torque applied to the model when it was moving at uniform speed. The dynamic simulations have forecasted the performance of products based on the model well and shown the importance of Adams in product development.
Influence of Magnesium Content on Preparation of Aluminum Foam
Authors: Luo Hong Jie , Zhang Ping , Liu Yi Han , Yao Guang Chun
Published: February 2012

Aluminum foam was prepared by foaming in melt route. Bubble growth and structure of the obtained foam blocks were investigated. Viscosity and surface tension of aluminum melt were also analyzed after adding Mg into it. The main results are as follows: expanding velocity of aluminum melt is accelerated after adding Mg and height of the foamed block is higher than that without adding Mg. The apparent density of aluminum foam increases first and then declines with increasing the Mg content. Intermetallic compounds existing in aluminum melt are largely oxidized when Mg is put into the melt and amount of the composite oxides increases obviously. These changes result in elevation of viscosity and reduction of surface tension in the aluminum melt.
Effect of the Non-Equilibrium Solidus Temperature on Length of Soft Reduction Zone
Authors: Qian Hong Zhi , Hu Pi Jun , Zhang Jia Quan
Published: February 2012

Solidus temperature is one of the important key parameters to describe the non-equilibrium solidification states. However, the study of the non-equilibrium solidus is not enough presently. In present work, the key Influence factors on solidus temperature have been discussed, and it can be calculated by a mathematical model for solute microsegregation during the solidification. The calculated solidus can be agree with the recommended values by some dynamic soft reduction model. It is shown clearly the thermal analysis with non-equilibrium solidus was consistent with the pin shooting experiments. And the effect of the non-equilibrium solidus temperature on solid fraction and the length of soft reduction zone at the solidifying front has been studied sufficiently. Dynamic soft reduction metallurgical effect with the non-equilibrium solidus has been agreed by carbon segregation index and Macroetched experiment.
Preparation of Raspberry-Like Polymer/Silica Composite Particles through Cationic Soap-Free Emulsion Polymerization
Authors: Fan Xin , Qin Qiu Ju , Wen Xiu Fang , Cheng Jiang , Yang Zhuo Ru
Published: February 2012

In this paper raspberry-like composite particles were prepared via cationic soap-free emulsion polymerization with silica sol as stabilizer and 2-(methacryloyl) ethyltrimethylammonium chloride (MTC) as cationic auxiliary monomer. According to the TGA and TEM results we could find that the electrostatic attraction supplied by MTC played a vital role in the adsorption of silica particles as well as the generation of raspberry-like morphology. The silica content and appearance of composite particles were found to be improved with the increasing amount of silica sol and MTC while varied little with changes of AIBA amount.
Research on the Microstructure and the Growth Mechanism of Oxidation Film of T91 Steels after Service
Authors: Zhong Wan Li , Li Zheng Gang , Wang Wei , Yang Bing
Published: February 2012

The character of structure and the micro-area elements of inner oxidation film were investigated by using metallographic microscope, electron microscopy, energy spectrum analysis and other testing methods based on samples of superheater and reheater tube cutting from three units. The results showed that the inner wall oxide layer of T91 steel superheater tube after running exhibited a double-layer structure, including inner and outer layer, and the interface between the two layers is the original metal surface. There exists a transition zone between the inner oxide film and metal matrix. A concentration gradient of alloy element in transition zone can be observed and the intergranular oxidation is present. The Fe-rich outer oxide layer does not contain Cr, which consists of Fe3O4, and the internal oxidation layer is composed of (Fe,Cr)3O4.
Dynamic Test of Nitrite Removal by SSI from Wastewater
Authors: Li Jun Guo , Li Shou Zhang , Tian Wei
Published: February 2012

Spherical sponge iron (SSI) with high activity and intension could be prepared through direct reduction by hydrogen. To investigate the optimized method of nitrate removal from wastewater by SSI, dynamic testing of nitrate removal has been investigated. pH values should be elevated quickly after the addition of SSI, and nitrate removal percentage reached to more than 88% during dynamic state experiment. Nitrate removal expressed two-phase removal process including the nitrate removal percentage increasing phase persistently and the nitrate removal percentage maintaining constant phase. The reduction temperature of SSI has significant influence on nitrate removal during fore-period. When the nitrate concentration was 5mg-N/L, nitrate removal percentage could only amount to 60% even the libration time prolonged to 200h. When the nitrate concentration increased to 50mg-N/L, the nitrate removal concentration increased quickly to about 80% and then the removal percentage maintained about 88%.
Study on the Characterization and Controlled Drug Release Carrier of Thiolated Chitosan-Based Nanoparticles
Authors: Chou Chih Wei , Shih Yang Chia , Wu Te Hsing
Published: February 2012

In this paper, we prepared and characterized the thiolated chitosan nanoparticles (CS NPs) Through modification. Bridged with a carbodiimide reagent, L-cysteine was therefore covalently bound to CS NPs which are capable of forming double bonds with thiol group and the mucus glycoprotein. A quantitative analysis of the widely used Ellman’s method can obtain the amount of thiol groups in various compounds. The resulted polymer conjugation displayed that the amount of thiol groups attached onto CS NPs, was increased with increasing concentration of cysteine. The method C exhibited greater conjugation ratio of thiol groups attached onto CS NPs. In particular, the evidence of thiol groups attached onto CS NPs was present in the thiolated specimens, can be shown by FTIR spectra.
Structure and Optical Properties of SnS Nanowire Arrays Prepared with Two-Step Method
Authors: Lin You Dao , Wen Xin , Wang Lai Sen , Yue Guang Hui , Peng Dong Liang
Published: February 2012

Abstract. Single crystalline SnS nanowire arrays have been synthesized by sulfurating the Sn nanowire arrays which were prepared with the electrochemical deposition. The obtained SnS nanowire arrays are charactered with the XRD, SEM, TEM and the UV/Visible/NIR spectrophotometer. And the results indicate that the nanowires with an average diameter of 50 nm and a length of several tens micrometers, which same with the as prepared Sn nanowires. There are two absorption peaks indicate with the direct and indirect bandgaps about the orthorhombic SnS nanowire arrays.
Analysis of Vibration Reducing Effects of Cone Shape Materials with Holes Installed on Platforms
Authors: Meng Ling Yun
Published: February 2012

Abstract: Drilling platforms in ice-infested regions tend to vibrate intensively, threatening the safety of personnel. Cone with holes as vibration-absorbed material is added to platforms so that the failure mode of ice sheet is changed and resonation of platform is avoided. Simulated analysis of breaking length of ice sheet is made and the comparison between observed breaking lengths and predicted ones is made and it is found that the results are in good agreement.
Study on Light Porous Sintered Material
Authors: Jiang Cong Cong , Li Guo Zhong , Li Qi Jin
Published: February 2012

A light porous sintered material was prepared with red mud, fly ash, silica fume as the main raw materials, mixed with a certain amount of foam, by the technology of casting, calcination and etc. The influence of calcined temperature on the flexural strength, compressive strength, shrinkage and other properties of sample was studied. The microstructure of sample was characterized by scanning electron microscopy (SEM) and then the sintering mechanism was studied. The results showed that the optimum calcined temperature was 1150°C, and for the best sample, its bulk density was 691kg•m-3, compressive and flexural strength were 4.2MPa and 3.2MPa, thermal conductivity coefficient was 0.110W• (m•K)-1, firing shrinkage was 3.9%.
Research on Antiseptic and Corrosion-Inhibiting Admixture for Concrete
Authors: Li Tao , Chen Xue , Li Qiu Yi , Wang Feng Can
Published: February 2012

Concrete buildings in coastal area are dual attacked by chloride and sulfate easily. The erosions make great damage to buildings. This research develops a new type of antiseptic and corrosion-inhibiting admixture for concrete. It is a kind of inner-adding inorganic powder and made up by compaction component, corrosion-inhibiting component and sodium nitrite. The test results show that this admixture has the ability to resistant chloride and sulfate erosion, the admixture also can prolong service life of buildings which are exposed to high concentration of chloride and sulfate.
Study the Properties of Mae-Khong Alluvial Gravel Concrete for Producing the Non-Bearing Thin Wall Concrete
Authors: Namboonruang Weerapol , Rawangkul Rattanakorn , Yodsudjai Wanchai , Suphadon Nutthanan , Yong-Amnuai Prayoon
Published: February 2012

This work studies the development of using the Mae-Khong Flat Shape Alluvial Gravel which mostly found in Mae-Khong River as the raw material of the concrete combinations (GVCM) to produce the non-bearing thin wall. There are three main material properties investigated: the compressive strength, the tensile strength and the thermal conductivity. All properties are also compared with limestone concrete (LSC) which is widely used in normal concrete works. Results show that all properties of both materials increase with increasing cured time. For GVMC, the compressive strength increases as 6.66% for cured time from 28 to 180 days. The ratio of compressive strength to tensile strength is 8.69 compared with LSC which the value is 8.89. These can confirm that GVCM has the enough quality to produce the non-bearing materials according to the Thai community product standard.
Experimental Study on Frost Resistance Properties of Pumice Mixed Aggregate Concrete
Authors: Huo Jun Fang , Chu Jian Jun , Yang Hui
Published: February 2012

Different amount of pumice were used to replace gravel to make mixed aggregate concrete, the fast freeze-thaw cycle test were conducted and the influence of pumice rate substitution to the frost resistance properties of concrete were studied.The mass loss rate, strength loss and relative dynamic elastic modulus were regarded as the evaluation index of frost resistance properties of concrete. Results showed that the mass loss rate and strength loss rate gradually decreased and the relative dynamic elastic modulus gradually increased with the increase of pumice rate, the mass loss rate, strength loss rate and the relative dynamic elastic modulus gradually decreased with the increase of freeze-thaw cycles. Polypropylene fibers could reduce the strength loss rate, improved the relative dynamic elastic modulus, but had little effect to improve the mass loss. Through the frost resistance, the frost resistance of concrete improved with the increase of pumice content, at the same time, polypropylene fiber also could improve the frost resistance of concrete.
Investigation on the Effect of Silica Fume on Shrinkage Characteristics of Portland Cement-Silica Fume Paste
Authors: Bui Le Anh Tuan , Chen Chun Tsun , Hwang Chao Lung , Kurniawan Fondly Reymont , Li Cheng Hsiao
Published: February 2012

The ring-test was used to evaluate the plastic shrinkage crack tendency of paste specimen added with silica fume in this investigation. Silica fume was used as a partial replacement by weight of cement from 0% to 30%. The compressive strength and drying shrinkage were also examined. The test results show that the addition of SF (up to 30%) increases the compressive strength of paste. No significant influence of silica fume was found on the drying shrinkage of paste. The crack index is significantly increased in the paste specimen added with 10% and 20% replacement. This shows that the addition of SF increases the plastic shrinkage cracking tendency of paste. Using the ring-test method to detect the plastic shrinkage cracking of SF paste can provide more accurate measurements, which is helpful to understand the plastic shrinkage crack tendency of paste added with SF.
The Growth Mechanism and PL Performance of Bat-Like ZnO Nanorods
Authors: Li Zong Mu , Zhao Shi Xia , Xu Fa Qiang
Published: February 2012

Bat-like ZnO nanorods were prepared by evaporation of Zn powders without any catalyst. The length of nanorods ranged from several micrometers to tens of micrometers. Growth mechanism of the nanorods was discussed combining field emission scanning electron microscopy and high-resolution transmission electron microscopy results. The photoluminescence spectrum was measured by using a He-Cd laser as the excitation source (325 nm) and all the results indicated the product had perfect crystal quality.
Analysis and Prevention of Pulling Inhibition and Stagnation of Slab Casters
Authors: Wang Yan Feng , Yang Zhi Zheng , Rao Jiang Ping , Cheng Jun , Peng Zhu Gang , Hong Xia
Published: February 2012

For case of pulling inhibition and stagnation of slab casters appeared in one continuous casting department of WISCO, Factors include stress of dummy bar systems, integrated frictional force , compression force and pulling speed control mode are analyzed to get the causes. The case was ultimately changed with countermeasures such as equipment optimizing and technology improving. The stability and productivity of continuous casting was improved obviously as long as more benefit being provided.
Analysis on Mechanical Properties of Lotus Fibers
Authors: Yuan Xiao Hong , Gan Ying Jin , Chen Dong Sheng , Ye Yuan Jing
Published: February 2012

To understand the fundamental mechanical properties of lotus fiber could provide theoretical basis for developing lotus fiber fabric. This paper is focused on the mechanical properties of lotus fiber under the state of wet, dry and normal temperature, which include the single tensile properties, the repeated tensile stress properties under constant elongation, stress relaxation and creep properties, and have comparation and analysis on the cotton fiber and the viscose fiber. The conclusion shows that the lotus fiber and viscose fiber are more effect by humidity than the cotton fiber. The fibre strength of lotus fiber was the biggest than cotton fiber and viscose fiber under the normal temperature and dry state. The elongation at break of viscose fiber was the biggest than lotus fiber and cotton fiber under the state of wet, dry and normal temperature. From wet state to normal temperature state to dry state, the fiber strength of lotus fiber increase gradually, and elongation at break gradually decreased. The plastic deformation resistance ability, the stress relaxation and creep properties of bamboo pulp fiber under wet state are best, and the dry condition are the worst.
Research on Special Cement for the Concrete with Ultra-Fine Iron Tailings
Authors: Liu Wen Yong , Yan Shuai , An Yong Ye , Li Hua Jie
Published: February 2012

This essay is the subject of national eleventh five support schemes: The analysis of key technology on emission reduction and comprehension utilization of solid waste from large iron ore mine (Number:2008BAB32B14).For the concrete with ultra-fine iron tailings the research on the new special cement has been successfully prepared by means of using a low dosage of crystal-core-element named CCE for short (which has an excellent capability to accelerate the hydration speed and develop the strength of the cement)and high percentage of blast furnace slag and other several industrial residue. Compared to the ordinary Portland cement grade 42.5, the new cement has several outstanding virtues such as lower use level of cement clinker, higher level usage of industrial residue and lower cost. According to the cement standard GB175-2007, strength of special cement sample NO.3 is same as the ordinary Portland cement grade 42.5 with the standard sand. When with ultra-fine iron tailings, the new special cement has higher strength after 28days than the OPC. That shows the special cement has an excellent long-term performance of concretion. The manufacturing cost of the new special cement sample NO.3 is decreased by 20.76% than the ordinary Portland cement grade 42.5, that will bring a great environment and economic effect.
Relationship between Akund Fibers’ Carding and Sliver Quality
Authors: Jiang Xiao , Cheng Long Di , Yu Jian Yong , Wang Qin , Stojanovska Elena , Xu Shan Wen
Published: February 2012

The akund fiber has great potential to be used in the textile industry benefiting from its excellent properties. The adoption of akund fiber from calotropis gigantea could substitute or supplement cotton as raw materials for textile fabric and might reduce the possible damage to the environment. Therefore, The study in this paper on the relationship between carding procedure and the quality of akund fiber sliver aimed at optimizing the process of this new kind fiber on a flat top card has significant meaning. The results in this paper show that high quality slivers can be produced by using new wires, low speed of card elements or proper akund fiber content in blended yarn. However, decreasing the number of moving flats in the main carding zone too much would deteriorate the sliver quality.
Using Mahalanobis Clustering Algorithm for College Student Learning Fundamental Mathematics
Authors: Chen Chin Chun
Published: February 2012

The popular fuzzy c-means algorithm based on Euclidean distance function converges to a local minimum of the objective function, which can only be used to detect spherical structural clusters. Gustafson-Kessel clustering algorithm and Gath-Geva clustering algorithm were developed to detect non-spherical structural clusters. However, Gustafson-Kessel clustering algorithm needs added constraint of fuzzy covariance matrix, Gath-Geva clustering algorithm can only be used for the data with multivariate Gaussian distribution. In GK-algorithm, modified Mahalanobis distance with preserved volume was used. However, the added fuzzy covariance matrices in their distance measure were not directly derived from the objective function. In this paper, an improved Normalized Mahalanobis Clustering Algorithm Based on FCM by taking a new threshold value and a new convergent process is proposed. The experimental results of real data sets show that our proposed new algorithm has the best performance. Not only replacing the common covariance matrix with the correlation matrix in the objective function in the Normalized Mahalanobis Clustering Algorithm Based on FCM.
Rheological Behaviors of Polyacrylonitrile Melt Using Ionic Liquids as a Plasticizer
Authors: Tian Yin Cai , Han Ke Qing , Qin Hui Lin , Rong Huai Ping , Yan Bin , Wang Dan , Liu Shu Ping , Yu Mu Huo
Published: February 2012

The rheological behaviors of polyacrylonitrile/ionic liquids (PAN/ILs) melt were investigated to determine the general processing parameters and offer an important theoretical foundation of plasticized melt spinning. A step was carried out to decide the accurate temperature through the temperature sweep and time sweeps. The impacts of the concentration and temperature on the modulus of PAN/ILs samples were studied by dynamic sweeps. The three-parameter Carreau viscosity model was used to predict the zero-shear viscosity from the apparent viscosity data. The PAN/ILs melt showed shear-thinning behaviors. The melt with higher PAN concentration was found to be more sensitive to the temperature. However the structural viscosity index of the melt first decreased and then increased with the increase of temperature.
Preparation of Highly Conductive Polyaniline in Carbamide Aqueous Solution Using SnCl4 as Initiator
Authors: Lin Guan Nan , Yu Qun , Wang Wei , Wang Gui Bao
Published: February 2012

In this paper, we demonstrated a novel method for the preparation of highly conductive polyaniline (PANI) compounded with Sn(OH)4. We obtained the PANI directly in the oxidation polymerization system via simultaneous reaction of aniline (using ammonium persulfate, APS as oxidant) and SnCl4 in carbamide aqueous solution. The resulting PANI was compounded with Sn(OH)4 had been characterized by FTIR, UV-Vis spectroscopy, X-ray diffractometry, thermal analysis, scanning electron microscope and conductivity measurements, and the results showed that PANI was in well doped state due to the hydrolysis of APS and the complex between PANI and Sn(OH)4. We are sure this alkali-guided polymerization to obtain conductive PANI will lead to the preparation of a new class of PANI composites.
An High-Performance Water-Based Drilling Fluid and its Application
Authors: Lv Kai He , Wu Xue Dong , Shi Tao , Ren Kuan Long , Liu Yu Xia
Published: February 2012

An high-performance water-based drilling fluid is a hot subject of research both at home and abroad in recent years. In this paper, the inhibition property and the influence of amino polyols AP-1 and aluminum polymer DLP-1 on drilling fluid properties were evaluated, on this basis, through the formula optimization, the high-performance water based drilling fluid was developed and and field applied. Both laboratory study and field application showed that aluminum polymer can reduce viscosity and filtration rate, and can effectively inhibit the hydration expansion of clay. Amino polyols had a little effect on the viscosity, gel strength and filtration of drilling fluid, but it had a good shale inhibition. This drilling fluid has good properties in rheology, filtration, inhibition and anti-contamination, with a satisfactory overall performance, which is helpful in solving wellbore instability that are due to unenven hydration or well developed micro fractures.
Effect of Carbon Fiber Reinforcement on the Mechanical and Tribological Properties of PA6/PPS Composites
Authors: Zhou Shao Feng , Wu Chao Qun , Chen Lian Hui , Zhang Qiao Xin
Published: February 2012

The mechanical and tribological properties of PA6/PPS blend reinforced by different content of carbon fiber were studied in the manuscript. It was found that the strength, modulus and hardness of PA6/PPS blend is improved apparently though breaking elongation rate and impact strength decreases to some extent. Average friction coefficient value of the carbon fiber reinforced PA6/PPS (PA6/PPS-CF) composites at the state stage is lower than PA6/PPS blend and PA6/PPS-CF10% exhibits the lowest friction coefficient of 0.34. As the content of carbon fiber increases, wear rate of the PA6/PPS-CF composites trends to increasing. These results is useful for providing some practical guidance for the application of polymer materials in the tribological field.
First-Principles Study of Electronic Structure of V-Si-N Nanocomposite Thin Film
Authors: Jia Hui Ling , Li Zhao Xi , Liu Xue Jie
Published: February 2012

In this paper, the method for plane wave ultrasoft pseudopotentials of first-principles is adopted to calculate electronic structures of three models including VN crystal, the absence of V atoms and the replacement of V atoms by Si atoms by the VASP software package. On the basis of the optimized VN’s lattice constant, the energy band structures and density of states(DOS) curves of those three models are analyzed. The results show that the 3d electrons of V atoms determine that VN crystal is a conductor. The crystal lack of V atoms forms a peak caused by the empty position near the Fermi level. Its valence band energy level splits and the ability to form bonds reduces to be a metastable phase structure. The formation of solid solution interface due to Si atoms replacing V atoms leads to the peak value of total DOS to decrease, the distribution of electrons to be more diffuse and the ability to form bonds to strengthen.
Effect of Energy Input of Welding Thermal Cycles on the Cryogenic Toughness of the CGHAZ in Steel 9Ni
Authors: Wang Duan Jun , Liu Li Gang , Wang Yu Hui , Zhao Xi Qing , Liu Wen Jun , Wang Qing Feng
Published: February 2012

The effect of energy input of welding thermal cycles with different t_(8/5) on the cryogenic toughness of the coarse-grained heat-affected zones(CGHAZs) in steel 9Ni was invested. The CGHAZ specimens for different energy input welding thermal cycles were prepared by GLEEBLE3500 thermal simulative experimental machine. The fracture morphology of welding thermal cycle specimens with different t_(8/5) was observed by using SEM. The microstructure, prior austenite grain and the appearance of packet in HAZ were observed by using OM. The block width was measured by using EBSD. The cryogenic toughness of the welding thermal cycle specimens becomes better with increasing t_(8/5). With increasing t_(8/5)，the appearance of granular bainite makes the space of martensite diminish, which refines the packet and block sizes. The refinement of martensite packet is the reason of the improvement of cryogenic toughness in steel 9Ni.
Numerical Analysis of Thermally-Induced Residual Stresses in Beryllium Caused by BeO
Authors: Mao Jing , He Li Jun , Xu De Mei
Published: February 2012

A numerical analysis was performed to investigate the thermally-induced residual stress caused by the thermal expansion mismatch between Be and BeO. Models were constructed according to the real situation that the BeO particles embedded in grains or distributed at the grain boundaries, where the temperature-dependent materials properties, particle volume fraction and size and interparticle distance were taken into account. In simulation, it supposes particles inside grain no interacting with others, particles along the grain boundary being a period distribution. Be is modeled as elastic and elastic-plastic material with bilinear kinematic hardening model. BeO is modeled as isotropic and linear elastic. All simulations are performed by using ANSYS finite element code. Results show that the size, location and the volume fraction of particles influence on the residual stress (strain) to different extent during cooling process.
Application of Ultrasonic Guided Wave Method for Flaw Detection in Coal-Fired Power Plants
Authors: Li Shi Tao , Cai Hong Sheng , Yang Jing
Published: February 2012

Ultrasonic guided wave method used for detection of cracks in the desuperheater header and main steam pipes of boiler in power plants has been reported. The dispersion curves of the guided wave for the main steam pipe were calculated and the wave modes used for the detection of notches were verified experimentally. One defect was found at the welded joint of the low temperature pipe on the furnace side. The time of flight diffraction (TOFD) was also carried out to verify the experimental results. The length, depth and height of the defect are 1200 mm, 18.9 mm and 5.5 mm, respectively. And one circular crack was found inside of the desuperheater header.
Failure Analysis of Hard Alloy Roll Rings and their Repairing Technology
Authors: Huang Li Rong , Liu Fei Fei , Chen Yu Hang
Published: February 2012

Roll rings are important parts in bars, and wire rolling, and their number consumed is large. They can fail and fracture due to defects of their own material and poor working conditions. There are many measures to prolong service life of roll rings, for example, their correct use and maintenance, suitable material, advanced manufacturing technology, and well machining quality, but mixed wear is inevitable. Such problems as surface defects and negative deviation of roll’s diameter caused by mixed wear can be solved by advanced repairing technology to make them meet users’ requirements, and prolong service life.
The Effect of Trace Boron on Corrosion Resistance of the Casted 0.04C-16Cr Ferritic Stainless Steels in H2SO4 Medium
Authors: Guo Tie Ming , Zhang Ding Cang , Han Chang Song , Hui Zhi , Zhao Li Ming
Published: February 2012

Three groups of 0.04C-16Cr ferritic stainless steels, with boron quality score of 0ppm, 16ppm and 26ppm, were smelted by a vacuum induction furnace. The chemical soak method, the tafel polarization curve method and the anode circular polarization curve method were used to research their general corrosion and intergranular corrosion resistance. The results showed that both general corrosion and intergranular corrosion of the casted 0.04C-16Cr ferritic stainless steels happened in dilute H2SO4 medium. The resuluts of electrochemical and chemical soak indicate that the addition of B improves intergranular corrosion resistance of 0.04C-16Cr stainless steel, moreover, the intergranular corrosion resistance increases with an increasing content of B. The addtion of B makes the general corrosion rate and self-corrosion current density of the 0.04 C-16Cr stainless steel reduced at active dissolution region in dilute sulphuric acid medium, so the general corrosion resistance of the 0.04 C-16Cr stainless steel is improved. The blunt-dimensional current density of the steel with 26ppm B is the lowest and the passivation zone of it is wider, so the stability of passive film and protection capacity of the steel with 26ppm B are the best. The electrochemical characteristics of general corrosion coincided with the results of soak corrosion.
Recovery of Copper and Cobalt from Spent Aerospace Material with Pollution-Free Oxidant
Authors: Xiao Yue Bin , Zhou Xue Jiao , Cao Lei , Gao Ya , Liu Da , Yuan Ming , Xia Wen Tang
Published: February 2012

The acid leaching of spent aerospace material with pollution-free oxidation is discussed. Effect of parameters including initial concentration of hydrochloric acid solution, leaching temperature, reaction time, agitation speed, liquid to solid ratio and concentration of oxidant on valuable element extractions are determined, the optimized conditions are 6 M, 60 °C, 30 min, 250 r/min, 6:1 and 0.0378 mol•L-1•min-1, respectively. The comprehensive results of experiments show that the extracting efficiency of Co and Cu are over 83% and 98% respectively when optimized conditions were adopted.
Review of the Research on Evaluation of Livable City
Authors: Wang Xiao Yan
Published: February 2012

The evaluation of livable city is a popular subject. From the main study perspective of livable city, this paper discussed the concept and connotation of a livable city, summarized the current indicators and methods for the evaluation of City Liability, and made the prospects on its future research.
Study on the Shearing Characteristic of the Epoxy Resin Matrix Composite Enforced Promiscuously by SiC Nano Fiber and Twaron Staple
Authors: Guan Li Ping , Zhang Jian Chun
Published: February 2012

The SiC ceramic is the perfect ballistic material in the modern war because it has lower density, the weight is lighter and the cost is moderate. In this paper, the shearing academic modular of the epoxy resin matrix composite enforced promiscuously by SiC nano fiber and Twaron staple was built and proved by the way of mathematic deduced and testing validated. And the shearing characteristic was analyzed. The result shows that the total volume percentage of the enforced fiber is bigger, and the shearing modulus of the composite is higher. The modulus of the composite would be higher if that of the matrix is bigger. If the volume percentage of the fiber with lower shearing modulus is bigger, the modulus of the composite would be lower. The mainly factor which influenced the shearing characteristic of the composite is not the shearing properties of the enforced fiber, but that of the epoxy matrix. The effect to the shearing characteristic of the epoxy resin composite enforced by the mixture of SiC nano fiber and Twaron staple is plus certainly.
The Study on the Change of Sheer Strength Characteristic Parameter and Soil Nail Firmness of Effect in the Condition of Freezing-Thaw Cycling
Authors: Jiang Chun Yan , Feng Yong , Zhou Yuan
Published: February 2012

By fine earth freeze-thaw simulated experiment and cut experiment in the room, this paper studied the sheer strength characteristic parameter before and after the freezing-thaw cycling, and got the change discipline of the internal cohesive force c, internal friction angle Ф in the different temperature range and the number of the freezing-thaw cycling, deduced the calculation formula of c, Ф and T(soil nail counteract evulsion force) according to the experiment data, and compared the effect of the firmness.
The Effect of Nano-Aluminum on Morphology and Properties of Polyimide Matrix Composites
Authors: Liu Li Zhu , Weng Ling , Shi Hui , Wang Feng Chun , Ding Jun , Lei Qing Quan
Published: February 2012

Nano-sized Al2O3/polyimide composite films based on Pyromellitic dianhydride(PMDA) and 4,4’-Oxydianiline(ODA) were synthesized by addition with different contents of nano-sized Al2O3 via in situ polymerization. Before addition, nano-Al2O3 particles were firstly modified by coupling agent DB550. The morphology, structure and properties including the mechanical and electrical properties were investigated. SEM microstructures analysis result indicated that the inorganic particles were homogenously dispersed in the polyimide matrix by means of the ultrasonic-mechanical method and the treatment of coupling agent DB550. XRD analysis showed that the addition of nano Al2O3 particles destroyed the molecular order of the PI matrix. Moreover, with the increased in Al2O3 content, the weaken effect on the molecular order also increased. The mechanical property decreased with the increase of Al2O3 content. Better electric breakdown strength could be achieved if the pure polyimide films were incorporated with nano-Al2O3 particles.
Research on Machining Simulation of Large Scale Spiral Bevel Gear Machine Tool
Authors: Xu Yan Wei
Published: February 2012

The machining coordinate system of spiral bevel gear machine tool is established through analyzing the machining mechanism of spiral bevel gear, and the three dimensional structure model of large scale spiral bevel gear machine tool is also established using the new cutting feed method. The numerical control machining model of large scale spiral bevel gear machine tool is proposed. Finally, the machining simulation of one pair of given large scale spiral bevel gears has been done, the result indicates that the machining simulation model meets the prospective design requirement.
Research Progress in Preservation of Postharvest Edible Fungi
Authors: Chen Xiang Ning , Jin Wen Bin , Dong Yin Ran , Meng Ling Chuan , Wei Qiang
Published: February 2012

Once edible fungi are picked, metabolism and inoculating microbes affect the quality of the products badly. This article expounds on mushroom freshness-keeping mechanism and on research progress regarding maturity, after-picking treatment technology, temperatures, and packaging materials that can influence edible fungi storage quality which can serve as a guide to edible fungus freshness-keeping technology research and production practices.
PP/Wasted PET Fabric Composites Compatibilized by two Different Methods: Mechanical Properties, Morphology and Thermal Stability
Authors: Lin Zhi Dan , Guan Zi Xian , Liu Neng Sheng , Li Zheng Jun
Published: February 2012

The composites of polypropylene (PP) and wasted PET fabric (WF) were prepared by extrusion blending and injection molding, and then, the interface of the composites was modified by two different types of compatibilizers, i.e., maleic anhydride grafted PP (PP-g-MA) and the mixture of methyl methacrylate (MMA) and styrene (St). The mechanical properties, morphology and thermal stability of these composites were studied.
A Novel Process to Synthesize NiCoMnO4 Nano-Powder for NTC Electro-Ceramics
Authors: Wang Jun Hua , Yao Jin Cheng , Chen Zhao Yang , Fan Yan Wei , Jia Dian Zeng
Published: February 2012

A pure spinel-type phase was attained by solid state reactions at room temperature, with no intermediate compounds. Its formation and the structural evolutions have been characterized by thermogravimetry-differential scanning calorimetry (TG/DSC) tests, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Related electrical analyses were also performed. The results showed that the powders and ceramics prepared by the solid state reactions at room temperature exhibit a good electrical property because of narrow grain size distribution, controlled morphology, and high purity. Most importantly, this new approach greatly simplifies the preparation processes.
Reliability Sensitivity Analysis for Differential Expansion of Steam Turbine by Saddlepoint Approximation
Authors: Li Le Xin , Su Chang Qing , Jin Ya Juan
Published: February 2012

Based on Saddlepoint Approximation method and sensitivity analysis method, reliability sensitivity analysis for differential expansion of steam turbine with random parameters are studied. On the premise of the probability distribution of random parameters, using Saddlepoint Approximation method, probability density function of limit state function of differential expansion of steam turbine is obtained. The result of Saddlepoint Approximation method is very close to the one of Monte-Carlo, and the computing speed is fast. Then, the sensitivity analysis method and probability density function were employed to discuss the variation regularities of reliability sensitivity and the effect of design parameters on reliability of differential expansion of steam turbine is analyzed.
Pareto and Cause-Result Diagram Analysis of Automatic Rifles Failures
Authors: Cai Wei , Wang Rui Lin , Li Yun Feng
Published: February 2012

In the high-technique war of the future, infantries are main strength across the battlefield, so automatic rifles are weapons that cannot be dispensable. This article introduces methods of Pareto and Cause-result diagram at first, and then sets up diagrams combining with dates of rifles composite life tests. Through analyzing the diagrams, typical failures are confirmed, and improving suggestions are put forward at last.
Product Design Research Based on Sustainable Concept
Authors: Cheng Jin Xia
Published: February 2012

In the premise of achieving corresponding functions, sustainable design means to take the most natural, harmless and energy-saving materials to realize the product functions to meet the need of the present without compromising the ability of future generation to meet their own needs. While with the Chinese characteristic features and the endless expansion demand on consumption, design is going on the opposite direction. The product design research based on sustainable concept is a re-examined view of human-oriented design in front of the challenge of limited resources protection. And with the help of unlimited creativities and design, we can care more about our nature and society on one hand. On the other hand, the silent affection and promotion on green, energy-saving and low-carbon living concept will also definitely influence our human being to be more rational.