bluuebunny/crossref_metadata_2025 huggingface dataset:
Sandstone Unloading Rheological Test and Model Parameters Study
Authors: Jiang Yu Zhou , Wang Rui Hong
Published: February 2011

Rock rheology is common in engineering practice, which has an effect on long-term security and stability of the project. In order to understand the rheological mechanical properties under the condition of unloading sand, automatic servo apparatus of triaxial creep of rock was used to have a rheological mechanical unloading triaxial test on sandstone, which got typical flow complete curves of rock. Rheological test results showed that rheological phenomena occured in sandstone, and its rheological properties were significant with large rheological deformation, especially in high-stress conditions, When the external load exceeded the long-term strength of rock samples, specimen deformation went through three typical rheological stages with time increasing, and ultimately speed up the flow breakdown. Based on the experimental results, analyzed and studied the rheological parameters that were obtained, and discussed unsteady character law of rheological parameters. defined rheological damage of rock in the accelerating flow process as the unloading capacity and time-related exponential function, and proposed corresponding damage evolution equation, brought damage evolution equation into Burgers rheological model, and obtained nonlinear unloading model of rheological damage of rock, used accelerating rheological test curve of sandstone samples under the condition of 15MPa confining pressure and 135MPa stress level to verify nonlinear unloading model of rheological damage of rock, and the results showed that the fitting results of rheological test data and the improved rheological model had good consistency, and the rheological model can reflect the three stages of nonlinear rheology of rock, which can reflect the rheological characteristics under the condition of unloading sandstone more accurately.
Numerical Simulation for Thermal Shock Resistance of Thermal Protection Materials under Temperature Rising
Authors: Li Wei Guo , Li Ding Yu , Wang Chao , Fang Dai Ning
Published: February 2011

Due to the complexity of service environment of thermal protection system on the aerocraft, the thermal shock resistance (TSR) of ultra-high-temperature ceramics (UHTCs), which are used as thermal protection materials, is no longer the material itself’s. Based on the restrictions of current experiments and the lack of theories, hafnium diboride (HfB2) is used to study the effects of the external constraint conditions and different thermal environment on the TSR of the UHTC in detail. The effects of different initial temperature, different external constraint conditions, and temperature rising rate on the TSR of the UHTCs through numerical simulation are discussed in detail in this study. This study can provide a more intuitively visual understanding of the evolution of the TSR of UHTCs during actual causative conditions.
Preparation and Characterization of MCM-22 Zeolite by Varying-Temperature Hydrothermal Synthesis
Authors: Cheng Yue , Su Xiao Yuan , Lu Mang
Published: February 2011

MCM-22 zeolite of high crystallinity was synthesized with varying-temperature hydrothermal method. Zeolite was characterized by means of XRD, SEM, TEM and TG-DTA. XRD pattern showed that the sample was MCM-22 zeolite. SEM analysis indicated that the MCM-22 sample is in the form of thin platelet-like crystals, and no amorphous material. TEM analysis exhibited regular shaped aggregate assembled by the independent growth of many small flaky crystals. N2-adsorption/desorption analysis showed that the pore size and BET surface area of MCM-22 were 3.5 nm and 387.8 m2/g, respectively. By means of the varying-temperature hydrothermal method, synthesis time can be effectively reduced, and energy consumption also decreases.
The Effect of Poisson’s Ratio on the Contact Traction Distribution of a Functionally Graded Coating
Authors: Liu Tie Jun , Wang Yue Sheng
Published: February 2011

This paper deals with the finite frictional contact of a functionally graded coating with considering the effect of Poisson’s ratio. We assume that a functionally graded coated half-space is indented by a rigid spherical punch and that the shear modulus of FGMs varies as exponential function. The whole contact region is divided into the central adhesion zone and the slip annulus. Within the slip annulus, the shear stress is limited by friction. By using the Hankel integral transform technique, the problem is reduced to a set of Cauchy singular integral equations. A numerical method is used to get the contact pressure and tangential tractions in the contact region for different Poisson’s ratio. The results show that the variation of Poisson’s ratio has obvious effect on both normal and tangential tractions. With the increase of ν, the peak value of the normal traction increases and that of the tangential traction decreases.
Calculation Error Analysis on the Strain Fatigue Life Predication Formula of Manson-Coffinn and Damage Stain Model
Authors: Wang Zhen Wei , Du Ping An , Yu Ya Ting
Published: February 2011

Mechanical components are subjected heavy alternate load in industries, such as engine crankshaft, wheel axle, etc. The fatigue failure happens after a long work loading, which affects the production cost, safe and time. So the fatigue life predication is fundamental for the mechanical components design. Especially, it is very important for heavy, high-speed machinery. In this paper, both main fatigue life predication formulas are introduced briefly, including Manson-Coffinn formula and Damage strain model. Then, shortages of above life predication formulas are pointed out, and coefficients are explained in detail. Further calculation error analysis is conducted on the basis of experiments on 16 materials. Results show that above life predication formulas lack calculation accuracy. Finally, it is pointed out that coefficients of fatigue life predication formulas are dependent of material performance. So it is unreliable that coefficients are constants for Manson-Coffin and Damage strain model.
Effect of Sulphite Sediment on Hydrogen Embrittlement Susceptivity of Hot-Dip Galvanized Steel Exposed to Simulated Marine Atmosphere
Authors: Zhang Da Lei , Jin You Hai , Li Yan , Tang Xiao
Published: February 2011

Hydrogen permeation and embrittlement behavior of hot-dip galvanized steels with different sulphite sediment on surface exposed to stimulant marine atmospheric environment was investigated by hydrogen permeation current measurement using modified Devanathan-Stachurski cell, slow strain rate tensile test and scanning electron microscopy technique. The results indicated that hydrogen permeation curves were increasing along with the sediment rising gradually. On the other hand, it was found that hydrogen absorption was accelerated by the cathodic protection of scratched steel surface afforded by zinc coating. Hydrogen absorption and permeation reduced the percentage elongation after fracture of galvanized steel specimens; meanwhile, the fracture characteristics of samples fringe occurred some lacerated phenomena, i.e., galvanized steels show a higher susceptivity of hydrogen embrittlement when exposed to marine atmospheric environment with sulphite.
Observations on the Correlation between Statistics of some Fatigue Crack Growth Data and Applied Loads for 2024-T351
Authors: Ni C.C.
Published: February 2011

Three sets of fatigue crack growth data tested under different constant-amplitude loads for CT specimens made of 2024 T-351 aluminum alloy are released, and the analyzed results presented in this study are specially emphasized on the correlation between statistics of these scattered fatigue data and their applied loads. Investigating the scatters of initiation cycle and specimen life, it was found that both the mean and standard deviation of initiation cycle, as well as the mean and standard deviation of specimen life, decrease as applied stress amplitude increases. Moreover, the negatively linear correlation between the median values of initiation cycle and applied stress amplitudes presented in linear scale, and between the median values of specimen life and applied stress amplitudes presented in logarithmic scale were found, where the initiation cycle and specimen life are all best depicted by normal distributions for all three data sets. Finally, the mean of intercepts and mean of exponents of Paris-Erdogan law for each data set were studied, and it was found that the mean of intercepts decreases greatly as applied stress amplitude increases, while the mean of exponents decreases slightly.
Fatigue Damage Assessment of the Engine Mount Bracket Using a Statistical Based Approach
Authors: Zakaria Kamarul Ariffin , Abdullah Shahrum , Ghazali Mariyam Jameelah , Nuawi Mohd Zaki , Padzi Mahfodzah M.
Published: February 2011

Fatigue damage assessment is very important in design process of the component to determine their durability under service loading conditions. In service, the great majority of structures and components are subjected to stress of variable amplitude loading. The purpose of this research is to analyse statistically of two types of strain signals from road loading and compare their effect on fatigue damage of the engine mount bracket. Strain gauges were attached to the engine mount bracket and were connected to the data acquisition set in order to capture the actual strain signals when an automobile was driven on two different road surfaces. The strain signals were then analysed using global signal statistic and integrated kurtosis based algorithm for Z-filter (I-kaz) method. Meanwhile, damage of the engine mount bracket was evaluated using finite element commercial software. From the analysis, it was found that the fatigue damage showed an increment with the respective statistical values of the strain signals.
Dynamic Mechanical Property of a Steel
Authors: Tao Jun Lin , Xu Wei Fang , Cheng Gang , Huang Xi Cheng , Zhang Fang Ju , Pan Xiao Xia
Published: February 2011

In order to realize the dynamic mechanical property of a steel, the quasic-static and dynamic compressive and tensile mechanical tests of a steel are carried out. Based on the stress-strain curves of the steel, the constitutive relation is presented and it can be used to describe compressive and tensile mechanical property correspondently. The stress-strain curves at different strain rate and the obtained dynamic constitutive relationship show that the flow stress of the steel is increased with strain rate increased. The dynamic tension experimental results show that failure strain and stress of the steel are increased small with strain rate increased, and the fracture of tension sample is ductile fracture.
The Equivalence Method of Protective Structures
Authors: Zhang Zhong Guo , Gao Bin , Liu Zhao Hui
Published: February 2011

In this paper, according to the structure of warships, the equivalence method of the protective structure with reinforcing ribs is presented abided by the principal of equivalence in rigidity. The minimized model and the equivalence model of the protective structure with reinforcing ribs penetrated by projectiles are investigated in experiment and numerical simulations, and the results show that the equivalence method of the protective structure is reasonable. The reinforcing ribs are extensively used in protective structures, especially in ship structures. The reinforcing ribs are characterized in extensive distribution range and little weight of unit length, and have the main effect that the rigidity requirement of the structure is satisfied so that the structure has enough rigidity stability. However, the big and the small reinforcing ribs in actual structures originally have small size of the cross sectional area (CSA). According to a usual model research method, after an original structure is proportionally reduced according to the minimized proportion of one to four [1], the size of the CSA of the big and the small reinforcing ribs becomes smaller, and the shape of the cross sectional area is shown in Figure1. Under such circumstances, an experimental research on the dynamic response of the reinforcing ribs under the impact load has the characteristics of great difficulty and bad feasibility, and in addition, the reliability of reflecting target characteristic by a proportionally reduced model is very low[2]. In order to study the action of the reinforcing ribs more objectively, the T-shaped cross section of the reinforcing ribs is converted to a rectangular cross section according to the principle of rigidity equivalence, and then, the action can be researched actually. The study method is given as follows.
Development of Industrial Ethernet Windows Driver for Motion Control System
Authors: Yang Lin , Zhang Cheng Rui
Published: February 2011

An industrial Ethernet based motion control system is presented in the paper. The first slave node in the line topology is responsible for the precise cyclic communication, and it will reduce the real-time requirement on the main controller. The communication protocol is implemented as Windows NDIS protocol driver, and provides higher priority than normal user mode application. In addition, the development environment and process are also discussed, through which the developer can debug the system software at a single computer in both simulated mode and real mode.
Effects of Different Thermal Treatment on Optical Properties and Microstructure of ZnO Thin Films
Authors: Zhang Dong Ping , Fan Ping , Zheng Zhuang Hao , Ru Li Li , Huang Jian Jun , Cai Xing Min , Chen Tian Bao
Published: February 2011

ZnO thin films were prepared by DC reactive magnetron sputtering at room temperature. Two of them were annealed with different modes under vacuum condition. One was annealed with constant temperature of 300°C ; the other was annealed with temperature rising step by step from room temperature to 300°C . By comparing the microstructure and optical properties of the as-grown and annealed samples, the effects of different annealing modes on ZnO films performances were revealed. The experiment results investigated that the sample annealed with constant temperature of 300°C has the high grain size and surface roughness. Both of the two annealing modes could release the intrinsic stresses to some degree. The optical band gap of the samples narrowed after annealing, and the two annealed samples have almost the same band gap. Strong green emissions are observed for all the samples, but the emission intensity decreased of the sample annealed with the temperature rising step by step compared with that of other samples.
Mechanical Properties and Crystalline Morphology of Blends of Poly(3-Hydroxybutyrate-Co-4-Hydroxybutyrate) with Poly(L-Lactide)
Authors: Lu Xiu Ping , Wen Xing , Zhu Fu Yan
Published: February 2011

Blends of poly (3-hydroxybutyrate-co-4-hydroxybutyrate) [P (3HB-co-4HB)] with poly(L-lactide) (PLA) were prepared by melt-mixing and subsequent injection molding, and their mechanical properties and morphology were investigated. The results show that the tensile properties, impact strength and spherulitic morphology depend strongly on the composition of the blend. The point of transition shows that phase inversion takes place at composition with 40 weight fraction of PLA in the blend.
Study on the Formation of Wood Zone Line Pattern Induced by the Fungi
Authors: Qin Lei , Guo Ming Hui , Qiu Jian , Liu Cui
Published: February 2011

Through the analysis of wood microstructure, the study revealed the reason of forming the wood zone line pattern, and analyzed the wood zone line pattern’s similarities and differences between the artificial cultivation and natural formation. And the wood zone line pattern was formed because that the fungal hyphae invaded into the wood inside. The research results showed that: (1) The causes for the formation of wood zone line pattern, took place when different fungi eroding the same tree, due to antagonism among the hyphae, and the zone line was formed on their against interface. (2) Artificial cultivation and natural formation wood zone line pattern were the same, their hyphae both entered into the wood cells, and formed the irregular, natural and beautiful pattern. The wood zone line pattern could be used as the woodwork surface decoration materials, they were the excellent materials of furniture and indoor decoration. The study laid a theoretical foundation for further research on artificial cultivation fungi coloring wood, really realized the wood biological coloring. And the wood zone line pattern was green, low-carbon, and environmentally friendly products.
Effect of Carburization Process on Adhesion Strength of Ti Carbide Layer on Titanium Alloy Substrate
Authors: Izman Sudin , Kadir Mohammed Rafiq Abdul , Anwar Mahmood , Nazim Engku Mohammad , Nalisa Adila , Konneh Mohamed
Published: February 2011

Titanium alloys are commonly used in biomedical application in hard tissues replacement especially for knee and hip implants. Surface modifications are required prior to diamond coating process for improving tribological and wear properties of the titanium alloy. In this study, experiments were carried out to investigate the effects of different carburizing times on the adhesion strength of carbide layer formed on the Ti-6Al-7Nb. Prior to carburization process, all samples were treated to remove residual stress and oxide scales by annealing and pickling processes respectively. Hard wood charcoal powder was used as a medium. The carburizing process was carried out for 6, 12 and 24 hours at 950 °C under normal atmospheric condition. Surface morphology, carbide layer thickness and adhesion strength were evaluated using SEM, XRD, 3D Surface Profilometer and Blast Wear Tester (BWT). It is found that a mixture of oxide and carbide layers formed on the substrate and the thickness of these layers increases with carburizing time. It is also revealed that the 24 hr carburizing time provides the strongest adhesion strength among the three and TiC as the dominant layer.
Encapsulation of Glycoprotein Extracted from Kiwifruit in Chitosan-Based Microspheres
Authors: Wang An Na , Wu Li Gen , Jia Lin Lu , Sun Yu Dan , Li Xiu Ling , Xu Xiang Ying , Wang Jie , Wang Chao , Zhang Yuan Yuan , Fu Qin Qin
Published: February 2011

Encapsulation glycoprotein extracted from kiwifruit in chitosan-alginate microspheres was prepared by ionic gelation method for controlling release by using various combinations of chitosn and Ca2+ as cation and alginate as anion. The concentration of chitosan, sodium alginate and calcium chloride could affect glycoprotein loading efficiency and the total release capacity of glycoprotein from chitosan-alginate microspheres. The maxmum amount of glycoprotein loaded and the minimum total release capacity were attained when 2% alginate, 0.7% chitosan, and 0.2M Ca2+ were crosslinked at pH 5.5, 37°C.
The Study of Automatic Programming System for Near-Field Electrospinning Direct Write
Authors: Lin Zhi Min , Yao Bin , Ye Jun Jun , Zheng Gao Feng
Published: February 2011

In order to control the machining process of Direct-Write based on Near-field Electrospinning automatically, an automatic programming system used for an open architecture CNC system is proposed in this paper. This system descirbes the machining trajectory via the 2D CAD drawing, from which the data is extracted by the system. According to the processing parameters, the data is classified and reordered, and NC codes are automatically generated. The system solves the problem in integrating the design and machining, makes it more convenient to experimental research and realizes patterned fabrication of micro/nano-structure,which provides a good experimental base for the development of electrospinning technology.
Dielectric Properties of Zn-Doped CCTO Ceramics by Sol-Gel Method
Authors: Xu Dong , Zhang Chen , Cheng Xiao Nong , Fan Yuee , Yang Tao , Yuan Hong Ming
Published: February 2011

The CaCu3-xZnxTi4O12 (CCZTO) (x=0, 0.06, 0.1, 0.2) ceramics were prepared by Sol–gel method. The XRD pattern shows that crystal structure of the sample with no Zn is basically single-phase. The SEM results indicate that the samples have porous structures and the gain size decreases with the content of Zn increasing. The dielectric properties of CCZTO were analyzed by Agilent 4294A. The experimental results show that the dielectric constants are less than that in other papers reported obviously because of their mesoporous structures. With the little doping amount(x=0.06, 0.1), a sharp decrease happened in the dielectric constant (εr). The higher εr was found when x=0.2, but its dielectric loss (D) had greatly increased and frequency stability of dielectric property became worse. The uniformity of gains was put forward to explain the results which showed great impact on the dielectric constant.
Influence of Random Disorders on Anti-Plane Waveguiding Modes in a Two-Dimensional Phononic Crystal
Authors: Chen A Li , Wang Yue Sheng , Zhang Chuan Zeng
Published: February 2011

In this paper, combined with the supercell technique, the plane wave expansion method is used to calculate the band structures of the two-dimensional phononic crystals with line defects and the random disorders in either radius or location of the scatterers. Phononic systems with plumbum scatterers embedded in an epoxy matrix are calculated in detail. The influences of the random disorder on the band structures of anti-plane waveguiding modes will be discussed. The displacement distributions are calculated to show the wave localization phenomenon. Propagation of the guided wave in the phononic crystals with different disordered degree is studied. The analysis is relevant to the assessment of the influences of manufacture errors on wave behaviors in waveguiding phononic crystals as well as the possible control of wave propagation by intentionally introducing disorders into the systems.
Effect of Thickness and Length of Ion Polymer Metal Composites (IPMC) on its Actuation Properties
Authors: Li Shu Feng
Published: February 2011

IPMC (ionic polymer metal composite), a kind of ionic electroactive polymer (EAP) has wide applications in the filed of bionics and artificial apparatus for its fast and large bending deformation under the low driving voltages. In this paper, thick IPMCs with various numbers of films were first fabricated by the hot-pressing method. Then the effect of the thickness on its properties, such as the tip forces and water uptake capability, were investigated. The effect of length of the IPMC on its tip forces was further studied. SEM (scanning electron microscopy) micrographs of IPMC specimen were also examined.
Application of Macro-micro Dual-drive System in Micro-EDM
Authors: Zhu Guo Zheng , Bai Ji Cheng , Guo Yong Feng , Ma Hu Liang , Liu Yan Wu
Published: February 2011

Micro-EDM technology has the advantages of no-contact and no-cutting force, it has been used in many fields. In order to use micro-EDM to machine proprietary micro array holes, which needs high precise of hole spacing and consistent hole diameter, a new macro-micro dual-drive system of micro-EDM have been made. It uses macro drive to move to a place, measures the error with the high precise grating, and uses micro drive to compensate the error. Online measurement proved that this method has important value if it will be used in micro-EDM.
Influence of Thickness and Density of Nonwoven Sound-Absorbing Material on the Sound-Absorption Capability
Authors: Su Wen , Qian Xiao Ming , Li Xin Yu , Liu Shu Sen
Published: February 2011

In this paper, the influence of thickness and density of nonwoven materials on the sound-absorption capability is studied through the serial experiments. The results show that the sound-absorption coefficient increases with material thickness increasing and this relationship is more distinct for low or mid frequencies than for high frequencies. When the material thickness is made constant, the sound-absorption coefficient increases with density increasing for low-mid frequencies, while the coefficient decreases with density for high frequencies. The conclusion is that the nonwoven materials with low density structure own better capacity in absorbing sound according to the experiment results.
Griseofulvin Solid Lipid Nanoparticles Based on Microemulsion Technique
Authors: Anurak Lorwongngam , Chansiri Gaysorn , Peankit Dangprasert , Somlak Kongmuang
Published: February 2011

The need for a topical drug delivery system of griseofulvin (GF) is dued to its poor oral bioavailability because of its low water solubility and excessively side effects. The preparation of griseofulvin-loaded into solid lipid nanoparticles (GF-SLNs) to nanometer range is expected to improve the dissolution rate by increasing the specific surface area. The aim of investigation was to produce griseofulvin-loaded into solid lipid nanoparticles by using a simple microemulsion technique, using glyceryl monostearate as solid lipid, polysorbate 20 as emulsifier, butanol and Transcutol HP®as co-emulsifiers. The GF-SLNs were evaluated for physical and chemical properties including GF release from GF-SLNs. The spherical particles were observed by TEM. The mean particle size of GF-SLNs was 165 nm and the zeta potential of GF-SLNs was -36 mV. There were interactions between GF and excipients in formula. The GF releasing profiles were obtained by a dialysis method with pH 5.5 phosphate buffer as medium, the release profile of GF was to be a prolong release of 63.53% within 12 hours.
Preparation of a Novel Night Vision Imaging System Filter for Display Applications
Authors: Dai Feng , Huang Xao Gu , Zhang Qi Tu
Published: February 2011

A novel NVIS filter based on NIR-dyes and polymer film was prepared through a special designed method. The relation between optical performance and NIR-dye content was discussed. The optical properties of the filter can be easily controlled by changing the amount of NIR-dyes. The results showed there was a good linear relationship between absorbance value and amount of NIR-dyes. Then, a filter with optimal amount of NIR-dyes was prepared. The filter showed strong absorbing ability in the region between 660nm and 930nm. Meanwhile, it showed sufficient transmittance between 400nm and 630nm. At last, an environmental test was taken to evaluate the performance stability of the filter.
Synthesis and Catalytic Study of Magnetic Separable Catalyst: M(Salen)-Functionalized Fe3O4 Polymer Composite Materials (M = Ru(III), Cu(II), Fe(III))
Authors: Shen Hao Yu , Pan Sheng Dong , Fang Fang , Shi Jia
Published: February 2011

M(Salen)-functionalized Fe3O4 polymer magnetic composites (Fe3O4-poly(MMA -DVB-GMA)-M(Salen), where M = Ru(III), Cu(II), Fe(III)) of approximately 20 nm in size were synthesized and characterized by IR, AAS, EA, TGA, XRD, TEM and VSM. These magnetic composites were air-stable, efficient catalysts for the selective oxidation of alcohols to aldehyde and ketones.
Research on the Superhydrophobic Modification of Polyvinylidene Fluoride Membrane
Authors: Yang Wen Fang , Zhang Zhi Qui , Gu Zhen Ya , Shen Xiao Xing , Zhang Qing Fu
Published: February 2011

In order to improve the hydrophobic property of Polyvinylidene fluoride (PVDF) membrane, in this paper nano-silica was modified by silane coupling agent firstly, then the modified nano-silica mixed with fluororesin，crosslinking agent and thickener to prepare the super-hydrophobic surface coating, finally the surface coating was covered on PVDF membrane. The results showed that the contact angle of the modified membrane was 162°and the sliding angle was 4°. The modified membrane was test by SEM and AFM, the surface coating on the PVDF membrane formed micro/nano-meter structure such as lotus leaves surface.
Efficient, Synthesis, Photochromism Properties of a Hybrid Diarylethene
Authors: Liu Wei Jun , Pu Shou Zhi , Jiang Duo Hua , Yan Pei Jian
Published: February 2011

An unsymmetrical diarylethene derivative bearing both phenyl and thiophene moieties, in which a methoxyl group was substituted at the para-positions of the terminal phenyl ring, was synthesized. At the same time, its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light both in solution and in PMMA film. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 297 nm UV light in hexane.
A More Exact Model for Predicting the Deflection of a Clamped Magnetostrictive Film-Substrate System
Authors: Li Ming
Published: February 2011

A more exact general analytical formula of preditcting the magnetostrictive coefficient is derived for any aspect ratio based the deflection difference between the x and y directions. The curvatures are found by minimizing the total energy of the system, which taking into account shear strain energy. The in-plane stress distribution including shear stress for short specimen is also given by the ANSYS® ﬁnite element package to illustrate the role of shear strain in the deformation of magnetostrictive film-substrate system.
Preparation and Properties of Form-Stable Phase Change Materials Polyacrylonitrile Fiber / Stearic Acid Blends
Authors: Guo Jing , Xiang Heng Xue , Wang Qian Qian
Published: February 2011

With stearic acid (SA) as phase change material, waste polyacrylonitrile fiber (PAN) as framework material, N,N-dimethylformamide (DMF) as solvent, form-stable PAN/SA blends phase change materials (PCM) are prepared by solution blending process. Phase change temperature and latent heat and the thermal stability of the PAN/SA PCM are characterized using Differential Scanning Calorimetry (DSC). The structure, crystalline morphology, and thermal insulation properties of the PAN/SA PCMs are investigated using Fourier transformation infrared spectroscope (FTIR), polarizing optical microscopy (POM), and temperature-recording instrument. The FTIR and POM results show that PAN and SA are combined by intermolecular forces, and SA is homogeneous distribution in the PAN matrix. The DSC results indicate that PAN/SA PCMs have high latent heat storage capacity of more than 115J/g, the phase transition temperature and phase transition enthalpy of the PCMs increase with increasing the mass percent of SA. Cooling curve of PAN/SA PCMs show that the PCMs have good insulation properties, the soaking time is continued for about six minutes, and the thermal insulation properties remain unchanged after five and ten times of thermal cycling. The best process condition is obtained by the soaking time and orthogonal experiment.
Studying on Preperation and Emulsifying Properties of Silk Protein Calcium Salt Made from Waste Silk
Authors: Li Jun Sheng , Cheng Hai Tao
Published: February 2011

One key step for silk protein further uses is to let them be dissolved in aqueous solution. However, the silk protein is usually not soluble in aqueous solution. Silk protein dissolved in calcium chloride solution is one of the few effective ways. Silk fibroin was well dissolved in 15-20min. in boiling calcium chloride solution [50% (w/v)] with the ratio of 15g dry waste silk per100mL calcium chloride solution. After dialysis, silk protein calcium salt unexpectedly showed excellent emulsification capacity and stability. Only 0.8-1.2% of silk protein calcium salt solution (50mL) could let 50mL soybean salad oil be mixed and emulsified well. Silk protein calcium salt may be used as a new protein-based surfactant.
Synthesis and Characterization of Some Functional Schiff Base Derivatives with Azobenzene Substituted Groups
Authors: Jiao Ti Feng , Li Xu Hui , Zhou Jing Xin , Liang Jing Ya , Ren Jing
Published: February 2011

Some functional Schiff base derivatives with azobenzene substituted groups have been designed and synthesized from the reaction of aminoazobenzene with different aromatic aldehydes. It has been found that depending on the size of aromatic groups, the formed Schiff base derivatives showed different properties, indicating distinct regulation of molecular skeletons. UV and IR data confirmed commonly the formation of Schiff base as well as aromatic segment in molecular structures. Thermal analysis showed that the thermal stability of Schiff base molecules with naphthalene segment increased slightly in comparison with other derivatives. The difference of thermal stability is mainly attributed to the formation of Schiff base group and aromatic substituent groups in molecular structure. The present results have demonstrated that the special properties of Schiff base derivatives can be turned by modifying molecular structures of objective compounds with proper substituted groups, which show potential application in functional material field.
Estimation of Hydrogen Diffusivity in Austenitic Stainless Steels by Microhardness Gradient Technique
Authors: Kan Wen Bin , Li Yong Feng , Pan Hong Liang
Published: February 2011

The present study developed a subsurface microhardness gradient technique to estimate hydrogen diffusivity of stainless steels, as per the similarity between concentration distribution and hardness gradient. Cathodic charging were performed on 304 stainless steels for 24 h in a 0.5 mol/L H2SO4 solution using a current density of 100 mA/cm2, with 0.25g/L Na2S as the hydrogen recombination poison. Microhardness in the cross-sectional region had an increase than the uncharged materials due to the hardening mechanism as found by martensite transformation. Hydrogen diffusivity was estimated using the microhardness data and the diffusion equation. The estimated diffusivity of hydrogen at 306 K in 304 stainless steels is 3.28×10-13 m2/s, which has good agreements with the one measured by time-lag electrochemical method in a previous research.
The Fault Analysis and Diagnosis of Proton Exchange Membrane Fuel Cell Stack
Authors: Lin Zhen , Wang Chang Hui , Liu Yu
Published: February 2011

In order to find the reason of the weak performance of a H2/O2 proton exchange membrane fuel cell (PEMFC) stack, a series of fault analysis and diagnosis tests were conducted. According to the test data, the problematic points were focused, and the fault types of the specific single cells were analyzed. It is found that a minimum of three groups of diagnosis tests based on three relatively high load resistances and a voltmeter could judge the working condition of the PEMFC stack and confirm the fault types of its single cells. The method is useful for quick detecting and handling of PEMFC stack in Industrial field and home usage.
Thermodynamic Analysis of Fuel Processor for Fuel Cell Vehicles
Authors: Li Cong , Wu Xun Cheng
Published: February 2011

Thermodynamic analysis was carried out for theoretical reaction of hydrogen produced from dimethyl ether (DME) auto-thermal reforming by using the minimum of GIBBS energy. The volume content of various gases were calculated at adiabatic condition as function of air to DME ratio (0.2~0.8), H2O to DME ratio (1~6) and pressure (0.1~0.6MPa). The result proves that the volume content of H2 decrease with the increasing of pressure. With the increasing of the H2O to DME ratio and the O2 to DME ratio the volume of H2 increases first then decreases. With the increasing of the H2O to DME ratio the volume of CH4 and CO decreases, the volume of CO2 increases. The model reliability was verified experimentally on self-designed equipment. The experiments data are closed to simulation results.
Comparison of Two Different Rolling Processes on Microstructure and Properties of Ferrite-Bainite Dual-Phase Pipeline Steels
Authors: Hu Yue Yue , Zuo Xiu Rong , Li Ru Tao , Wang Zhen Wei
Published: February 2011

The microstructure and mechanical properties of ferrite-bainite dual-phase pipeline steels respectively produced by thermomechanical control process (TMCP) and intercritical annealing were studied using optical microscope, scanning electron microscope (SEM), Vickers hardness tester and MTS 810 servo-hydraulic machine. The results show that these two processes obtain different morphology and distribution of microstructure, but the mechanical properties of them are similar and superior, especially the yield ratios are low. It is found that for TMCP steel, the grains of ferrite are large and the average ferrite grain size is approximately 6.1µm. The bainite structures are lump-shaped with concentrated distribution in the ferrite matrix and the band structure is obvious. For steels produced by intercritical annealing process, the grains are finer and the distribution of bainite is uniform on the ferrite grain boundaries. From the rolling plane to the centre, the grain sizes of ferrite in these two microstructures increase obviously, and the volume fraction of bainite first increases significantly, then decreases slightly in the TMCP steel and the average volume fraction is approximately 60.1%. However, the bainite volume fraction in the intercritical annealing steel decreases gradually and the average volume fraction is approximately 35.4%. Moreover, hardness values in through-thickness direction are uniform in the TMCP steel and these values are also similar in the intercritical annealing steel except the values in the region near the rolling plane are much larger.
Preparation and Visible-Light Photocatalytic Activity of TiO2 Nanotubes from a Hydrothermal Method
Authors: Liu Rui , Yang Wein Duo , Chueng Hui Ju
Published: February 2011

TiO2 nanotubes were synthesized using TiO2 powder as raw material from a hydrothermal method. It was observed that the sample prepared at 130°C and calcined at 450°C only anatase formed, but the sample calcined at 800°C, both anatase and rutile formed. The obtained TiO2 nanotubes prepared at a hydrothermal temperature of 130°C and calcined at 450°C have a greater surface area of 356.8m2/g. Moreover, the TiO2 nanotubes demonstrate the photocatalytic degradation of methylene blue solution effectively by exposing the nanotubes in aqueous solution under visible light.
Preparation and Characterization of Potassium Ferrate
Authors: Tan Xun Mei , Ji Fang Ying , Li Si , Lu Peng , Zhang Gui Zhi
Published: February 2011

In this paper, electrolysis and hypochlorite oxidation methods are adopted for the preparation of potassium ferrate, focusing on increasing the production yield and product’s purity. The oxidation of benzopyrene by potassium ferrate was investigated. The yield of potassium ferrate prepared with hypochlorite at optimized conditions is 21% higher than that of using electrolysis method. With the presence of hypochlorite, various conditions of oxidation reaction were determined as following: reaction temperature 25°C, re-crystallization temperature of -5 °Cand reaction time 40 minutes, which all contribute a yield of 80%. Spectrophotometric was used to analyze the purity of the product, which was measured up to 97%. XRD and IR were used to characterize the final product. The aqueous stability of potassium ferrate at various pH values was investigated. It was found that potassium ferrate solution had a maximum stability at pH 9-10.5. With three-dimensional excitation emission matrix fluorescence spectrosopy technique, the reaction of ferrate and benzopyrene (BaP) in aqueous phase which is a representative polycyclic aromatic hydrocarbon, was also investigated. The maximum degradation (49.5%) of BaP was gained at conditions of pH 9.5, Fe(VI): BaP molar ratio of 1:5, reaction time of 3 hours.
Photodegradation of Gaseous Toluene by the CdS/TiO2/ACFs Composites under Daylight Irradiation
Authors: Zhao Wen Xia , Guo Bin , Ren Ai Ling
Published: February 2011

To improve the photocatalytic application performances of TiO2, in this work, firstly CdS modified Degussa P25 TiO2 (CdS/TiO2) composites were prepared, then they were loaded on activated carbon fibers(ACFs) by dip-coating method. The composites were characterized by XRD, UV-vis, SEM, EDS and BET. Their photocatalytic activities under daylight were investigated by the degradation of gaseous toluene. The results showed that CdS/TiO2 composites mainly composed of anatase TiO2 and little CdS phases; CdS/TiO2 absorption edge had a pronounced “red shift”, the corresponding absorption edge wavelength of CdS/TiO2 composites were extended to 740 nm, respectively. From EDS spectrum, the main elements of CdS/TiO2/ACFs were Ti and O and a small quantities of S and Cd. CdS/TiO2 loaded on ACFs was in the form of small clusters, but not very uniform; compared with original ACFs, the surface area and pore volume of CdS/TiO2/ACFs decreased slightly, while the average size remained unchanged. The photodegradation rate of toluene by CdS/TiO2/ACFs composites under daylight irradiation was markedly higher than that by TiO2/ACFs, the maximal increasing rate reached as high as 18%.
Post-Doping of ZnO with Cu and its Effect on their Photocatalytic Production of Active Oxygen Species
Authors: Xu Xiao Ling , Chen Dan , Duan Xing , Yi Zhi Gang , Zhou Zuo Wan
Published: February 2011

Cu doping zinc oxides (ZnOs) were prepared by a post doping process with CuCl2 at high temperature. With the increase of the dopant loading, the lattice constant c decreased firstly and then increased, which indicated that the doped Cu atoms substituted for Zn atoms at lower loading and extra dopant of the Cu atoms existed as interstitial atoms. UV-Vis diffuse reflectance spectra (UV-DRS) illustrated that the energy band gap was effectively narrowed after Cu doping. The photocatalytic production of hydroxyl radical (•OH) and superoxide anion (O2-) were determined by terephthalic acid with fluorescence spectrophotometer and nitroblue tetrazolium with UV-Vis spectrophotometer respectively, and the results showed that both the photocatalytic production of •OH and O2- were deceased with the increase of the dopant concentration, which indicated that the recombination centers were formed in the samples.
A New Kind of United Treatment Technology of “Three Wastes” from Paper Mill and Flue Gas from Boiler
Authors: Yao Jing Hong
Published: February 2011

Combining with the production practice in the particular consortium of the paper mill, power plant and calcium carbonate fines factory, a new kind of united treatment technology is designed. The technology is mixing the waste pulp and waste scum with coal to finish the in-furnace desulphurization, spraying waste water to the flue gas to finished flue gas desulphurization and using waste hydrogen of calcium as absorb material. This method can comprehensive use of resource to reach a better economic effective and social benefit. It reduces the processing cost and avoids city environment pollution. The three factories have mutually pleasant business. The technology opens up a new effective approach of desulphurization and can be good example to the same enterprises. An economical benefit is analyzed.
Technology Optimization Study on Preparation of Activated Carbon from Rice Husk Cracking
Authors: Gao Feng , Ge Ying Xin , Zhao Jia , Yang Hai Xia
Published: February 2011

Response surface methodology (RSM) was adopted to study the key parameters such as activation temperature, activation time, and active agent amount in order to increase activated carbon iodine adsorption value from rice husk. A second order quadratic equation was established and the applicability of model and interaction involved factors on predicting the iodine adsorption value was verified. The results indicated that the effect on the iodine adsorption value was as follows: activation temperature, activation ratio, activation time. The optimal levels for achieving the highest iodine adsorption value were obtained, including activation temperature of 550°C, activation time of 48min and activation ratio of 1.25. The iodine adsorption value reached 1464.793mg/g under optimized conditions. Iodine adsorption value was conducted under the optimum condition and the results showed the average relative error 0.58%, it proved that the models fitted well, the experimental data and the model were feasible.
Pollution Assessment of Luanhe–Beidaihe Estuary by Eutrophication Index and Biodiversity Index
Authors: Wang Su Feng , Jin Yin Long
Published: February 2011

Several pollution assessment indexes were applied in the pollution evaluation of Luanhe-Beidaihe Estuary. The results of evaluation by single diversity index of phytoplankton (DIP), diversity index of zooplankton (DIZ), and diversity index of macrobenthos (DIM) showed that the environment of seven sections were all not severe polluted. Otherwise, the results of evaluation by eutrophication index (E. I.) showed that six sections (section A, B, C, D, E, and F) were in the level of eutrophication, only section G was in the level of mesotrophy. Pollution assessment by E. I. was more appropriate than biodiversity index, according to the fact of ‘red tide’occurrence in August 2009. It was suggested that the comprehensive pollution index, considering both of the response of pullution and the cause of pollution simultaneously, should be developed to reduce the the discrepancy resulted from the pollution assessment by singular index.
Catalytic Hydrogenation of Nitrate Ions over Pd-Cu/ZSM-5 Catalyst
Authors: Gao Wen Liang , Li Fang
Published: February 2011

Palladium-copper bimetallic catalysts supported over different supporters were prepared by chemical reduction method, and their catalytic performance was investigated with the hydrogenation of nitrate ions in drinking water under mild conditions. The results show that Pd-Cu/ZSM-5 bimetallic catalyst has the highest catalytic activity among all used catalysts. In addition, nitrate conversion influenced by metal content, metal molar ratio (Pd:Cu) and the addition of CO2 are also discussed. It is well established that the addition of CO2 has changed the reduction path of the intermediate nitrite, but is no influence on the steps of nitrate-to-nitrite reduction. In the end, the mechanism of catalytic nitrate reduction was discussed on the basis the literature results.
Synthesis of a Supported Amorphous Ni-B /TiO2-Al2O3 Alloy Catalyst by Electroless Plating
Authors: Lan Ling , Ge Shao Hui , Hou Yuan Dong , Liu Kun Hong
Published: February 2011

A supported amorphous Ni-B/TiO2-Al2O3 catalyst was synthesized by a silver-catalyzed electroless plating method. To control the deposition of Ni-B particles on support, the distribution and load of silver clusters were designed by combining the photocatalysis of TiO2 and the sol-gel technique. The as-prepared catalyst exhibits superior catalytic activity in the hydrogenation of sulfolene.
Study on Dynamics of the Bionic Mechanical Coupled Diaphragms for Sound Source Localization
Authors: Wang Qing Sheng , Liu Xiao Hang , Zhu Xin Lei , Rao Zhu Shi
Published: February 2011

Sound source localization is always of great value in many engineering applications. In recent years, studies on orientation mechanisms of the auditory systems and research of bionic structures of subminiature creatures, especially of the parasitoid fly Ormia Ochracea which has a remarkable ability to detect the direction of the incident sound stimulus despite of its tiny body size, may provide preferable solutions for the miniaturization of acoustic localization structure. In this paper, the bionic acoustic sensing device are set up and taken as the research object to find feasible orientation mechanisms, and the dynamics of the bionic mechanical coupled diaphragms are analyzed. These works provide the basis for the manufacture of experimental acoustic sensing device. In the last part of this paper, experiments on bionic acoustic sensing device are conducted after the test system has been established. The measured data and the analyses based on the measured data demonstrate that the modeling methods and theoretical study in this paper are correct.