bluuebunny/crossref_metadata_2025 huggingface dataset:
Practical Isolation of Bullatacin from Annona muricata Leaves Extract Using an Open Column Chromatography Technique
Authors: Mulia Kamarza , Winarcahyo Silvester W. , Krisanti Elsa , Kurniasuci Dewi
Published: February 2014

Annonaceous acetogenins are bioactive compounds present in the leaves of Annona muricata (soursop) with significant anti-cancer activities. In this study, acetogenin-rich ethanol fraction extracted from soursop leaves was further separated and isolated using a simple open column chromatography technique with silica gel as the stationary phase. The separation procedure consists of three steps, each step employing sequential elution with organic solvents having different polarity as the eluent. Eluted fractions rich in acetogenin compounds were identified using the Kedde reagent which formed a distinctive dark green complex with the unsaturated γ-lactone group present in all of the annonaceous acetogenin compounds. HPLC analysis showed that the initial methanol fraction, as well as isolates from the second and the third isolation steps, contain bullatacin, squamocin, squamostatin-A, and squamostatin-D. Bullatacin produced from this study can be used further as a standard compound for quantitative analysis of other acetogenin compounds contained in soursop leaves extract.
Crystallite Size Characterization of Mechanically Alloyed of (Ba,Sr) Hexaferrite and (Ba,Sr) Titanate Composite System
Authors: Novizal Novizal , Manaf Azwar , Sardjono P.
Published: February 2014

Barium - Strontium Hexaferrite and Barium Strontium Titanate are both well established materials which widely used respectively as permanent magnets and piezoelectric devices. As the properties are a structure sensitive, materials structure as well as crystal structure must be properly designed to meet a specific application. In this paper, we report our recent investigation on material structure analysis of Ba0.3Sr0.7Fe12O19 and Ba0.7Sr0.3TiO3 composite system prepared by a mechanical alloying process to promote feroic properties. The average of particle size for composites system was found initially increased to a large size of 9 μm after mechanically milled for 30 hours and then start to decreased to smaller size of ~ 5μm when the milling time was extended to 80 hours and showing trend toward further reduction in mean particle sizes. In the latter case, the XRD trace for milled powders showed broadened diffracted peaks pattern due to deformation during mechanically milling. After sintering at a temperature of 1050 °C much finer crystallites of 7-13 nm size in a dense pellet were observed. Hence, sintering to the milled particles has promoted formation of nanocrystal containing particles. The mean crystallite size for magnetic phase was about more than 350 times smaller than the mean particle size of composite particles. Finer crystallite sizes were found in B3SF in which the mean was about 700 times smaller than the mean particle size. The magnetic and electric properties of the composite system are also discussed.
Thermal Decomposition of Phosphate Ore by Using Differential Scanning Calorimetric Method
Authors: Ma Lin Zhuan , Huang Chao , Guo Jun Ming , Wang Zhi Ying
Published: February 2014

Phosphate ore was decomposed by using thermogravimetric (TG) and differential scanning calorimetric (DSC). The TG-DSC curves contained different sizes and heating rates. The results showed that phosphate ore had four weight loss stages at the range of 40 ~ 1100°C. With the particle size decreasing, the third weight loss stage became more obvious in TG curves and the endothermic peak became sharper in DSC curve ; the starting and ending temperature of thermal decomposition process moved to higher,the weight loss rate also tended to increase; the activation energy of phosphate ore endothermic decomposition process was calculated by Owaza method in 600~800°C, the average activation energy was 202.80 kJ / mol. It provided a basis for the utilizing of phosphate ore.
A Material Selection Method Based on Finite Element Method
Authors: Wu Sheng Bin , Liu Xiao Bao
Published: February 2014

A new method for material selection in structure design based on the theory of the finite element method was presented. The method made material selection and structure design working at the same time. The mathematical model was established based on the finite element method. Finally, the material selection of an excavator's boom was verified, the results show that the proposed method is effective and feasible.
The Study on the Pipe Retracting Shape Parameter Identify of Quantum and Immunity Algorithm
Authors: Liu Zhan Jun
Published: February 2014

The point of quantum and immunity algorithm is concluded. A identify model of quantum and immunity algorithm network is constructed. The input and output design of pipe retracting shape parameter is given, and the collection and deal of sample data is also given. Using quantum and immunity algorithm network does the imitate sample of model. The identify result of satisfaction is given. The new field of the pipe retracting shape parameter identify of quantum and immunity algorithm network is opened.
Application of Distribution of Oxygen Coefficient in Explosive Neutron Detection
Authors: Ding Wen , Guo Tao , Ji Chong , Shen Rui Qi
Published: February 2014

Oxygen coefficients of 396 explosives, including liquid and solid explosives, 177 dangerous materials, including oxidants, combustible substances, chemical hazards and narcotics, and 9 common packing materials were collected and compared. It can be seem that the explosives can be distinguished from non-explosives by oxygen coefficient with boundary 0.3 to 1.2. This result can support a convincing proof for explosive neutron detection.
Fatigue Propagation Life Evaluating for Materials or Components Suffered Load Spectrum by Quantitative Fractography
Authors: Liu Xin Ling , Chen Xing , Tao Chun Hu
Published: February 2014

Quantitative fractography is the important tool for evaluating the fatigue propagation life about material research and manufacturing process perfect, it is very useful in the circumstances that crack expands inside of the material or the crack cannot be observed because of the hidden part of the component. In-service components are usually suffered different load spectrums, and the fracture characteristics are combined created by random load spectrum and block spectrum, which are beach marks, small beach marks and fatigue striations. The most important thing for fractography quantitative analysis is to confirm the parameter used for evaluating the fatigue life and determine the relationship between the parameter and load spectrum. The relationships between different fracture characteristics and load spectrums are analyzed, and the selection means of characteristic parameter for different load spectrums are proposed. This paper also discussed a case of fatigue propagation life estimation of some aircraft lower wall panel suffered in-service aircraft flight load spectrum.
Design of a Simple and Demountable Experimental Device for Drag Reduction of Super Hydrophobic Surface
Authors: Fu Xin Sheng , Mei Lei , Wang Da Zheng
Published: February 2014

In recent years, super hydrophobic surfaces for fluid drag reduction effectively promote the development of drag reduction technique. For the experiment of surface friction test, traditional water tunnel device and popular PIV technique are both complicated and expensive. It is significant to design an experimental device which can be applied easily with little error. In this paper, we design a simple and demountable experimental device for drag reduction based on the calculation of resistance, friction and the specimen strain and deflection. Application technology of strain gauge sensor, the device could realize the drag resistance test on small friction. By means of analyzing the hydrodynamic of test section, we change and simulate partial structure of the test section to optimize the experimental apparatus. With the help of this device, we can measure small friction resistance directly by amplifying and output the small mechanical signals.
Study on Macroscopic Morphology and Microstructure of Single Ni60 Laser Clad Tracks Prepared Using a Variable Laser Beam Shaper
Authors: Sun You Zheng , Wang Si Yu , Wellburn Daniel , Shang Shuo , Cheng Jian , Chen Sui Yuan , Zhang Bin , Liang Jing , Liu Chang Sheng
Published: February 2014

The objective of the present study was to find the influence of laser beam shape on macroscopic morphology and microstructure of single Ni60 laser clad tracks. Laser cladding of Ni60 alloy powder can be used to manufacture and remanufacture backup rollers for the steel industry. Controlling temperature distribution can assist with achieving favorable macroscopic morphology and microstructure. Five different beam profiles were used in our experiment to prepare clad tracks. The beam profiles varied in terms of the ratio of energy densities between the internal and external parts. The macroscopic morphology and microstructure was tested using SEM. The study founds decreasing the ratio is possible to achieve wider clad tracks with a larger cross section area. It was found that microstructure in upper region tended to form net-like dendrite microstructure at low energy density ratios.
Comparison of Surface Properties of TiN and TiAlN Coating Prepared by Arc Ion Plating for the Improvement of Life-Time Extension of Tool Steel
Authors: Sun Guo Dong , Yi Deng Liang , Liu Chang Hua
Published: February 2014

TiN and TiAlN films have been coated on the surface of tool materials by various methods for the life-time extension of tool. In this work, for the improvement of hardness and adhesion of coating to SKD61 substrate, radical nitriding (RN) of substrate was carried out at 450°C for 5 hours in ammonia gas pressure of 2.7×103 Pa. The results showed that TiN and TiAlN coatings were distributed uniformly on the SKD 61 substrate. And the film thickness was up to 4 μm, which showed so high deposition efficiency (~ 66.7 nm/min) of arc ion plating at this typical process condition. For both coatings, the TiN phases could be detected and the (111) was dominant crystallite grown orientation. The AlN crystallite structure could be detected as expected in TiAlN film. The critical load of TiN film (22.36 N) was slightly smaller than that of TiAlN film (23.88 N). With increasing the load during scratch test, the friction coefficient of TiN film rose quickly, but friction coefficient of TiAlN had a little change, even decreased slightly.
Surface Roughness Study of Milled Carbon Fiber Reinforced Polymer (CFRP) Composite Using 4 mm 2-Flute Titanium Aluminum Nitride (TiAlN) Coated Carbide End Mills
Authors: Konneh Mohamed , Izman Sudin , Dzahi Padil Mirza Emmil , Roszat Rosniza
Published: February 2014

As the goal for aircraft weight reduction and low fuel consumption becomes a dire concern in aerospace industries, there is driving desire for the increasing use of advanced exotic materials such as composites, titanium and Inconels in the aerospace industry because of their high strength to weight ratio. Nevertheless the inherent anisotropy, inhomogeneous properties of CFRP and low bonding strength within the laminates make machining of these composite materials results in several undesirable effects such as delamination, micro-cracking, burr, fiber pull out and breakage. This paper discusses an experimental investigation into the influence of machining parameters on surface roughness when milling CFRP using 4 mm-diameter 2-fluted carbide end-mill coated with Titanium Aluminium Nitride (TiAlN). Relationship between the machining variables and the output variables is established and a mathematical model is predicted for the surface roughness produced during the milling process for the machining conditions investigated.
Research on the Conductive Property of CNT Nanopaper Facilitates the Actuation in Shape Memory Polymer Composites
Authors: Zhang A Ying
Published: February 2014

A method of synthesizing three-dimensional self-assembled multi-walled carbon nanotube (MWCNT) nanopaper on hydrophilic polycarbonate membrane was investigated. In combination with shape-memory polymer (SMP), the conductive MWCNT nanopaper facilitates the actuation in SMP composite induced by electrically resistive heating. The process is based on the very well-defined dispersion of nanotube and controlled pressure vacuum deposition procedure. The morphology and structure of the nanopaper are characterized with scanning electronic microscopy (SEM) over a wide range of scale sizes. A continuous and compact network observed from the microscopic images indicates that the MWCNT nanopaper could have highly conductive property. The experiment results show that the electrical resistivity of MWCNT nanopaper decreased as temperature increase. SMP composites recovery from a fixed benting shape to the oroginal shape under a constant DC voltage.
Microstructure Analysis on GMAW Additive Manufacturing Parts Constrained by Electromagnetism
Authors: Meng Fan Jun , Ba De Ma , Yin Feng Liang , Du Jun
Published: February 2014

A GMAW additive manufacturing process is performed with H08Mn2Si wire to fabricate a cube forming part. A optical microscope was used to observe the cross section aspect of forming part and the structure mechanism has been analysed. The results demonstrate that the forming part structure presents a characteristic that macrostructure is uniform and microstructure changes circularly. The circularly heating pattern of GMAW surfacing forming results in circular microstructure change and preheating of formed bead to subsequent bead and postheating of subsequent bead to formed bead are primary reason. Electromagnetic stirring effect of longitudinal dc magnetic field to molten pool can break dendritic crystal and refine crystal grain, which is in favor of enhancing forming part performance.
The Crystallization Research on the Zr-Based Bulk Metallic Glasses by Ion Thinning
Authors: Bai Ying Liang , He Lian Long
Published: February 2014

Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD) were used to investigate crystallization of the Zr70Cu8Ti7Ni15 bulk amorphous alloy, the results show that the edge region of BMGs sample produces nanosize Nickel crystals using the method of the ion thinning to make the TEM sample. The quantity of nanocrystals is proportional to the time of ion thinning and they are not residual crystals in the BMGs.
Two-Step Identification of Instantaneous Cutting Force Coefficients and Cutter Runout
Authors: Hao Hong Yan , Tang Wen Cheng , Wang Bao Sheng
Published: February 2014

Cutting force coefficients and cutter runout parameters are the key factors for accurate prediction of instantaneous milling forces. A new two-step identification method is presented to calibrate them in end milling. Based on analyzing effects of cutter runout on milling forces, a method of extracting nominal milling forces from measured milling forces is proposed. By calibrating average cutting force coefficients and corresponding average chip thickness, an approach to evaluate the instantaneous cutting force coefficients is proposed. Then, an iterative method is presented to identify cutter runout, and the procedure is also given in detail. Milling tests are performed to test the proposed method, and validity of the identification approach is proved by a good agreement between predicted results and experimental results.
Cutting Performance of TiB2/WC/h-BN Micro/nano Composite Gradient Self-Lubricating Ceramic Tool when Machining Carbon Steel
Authors: Chen Hui , Xu Chong Hai , Xu Xiu Guo , Fang Bin , Xiao Guang Chun
Published: February 2014

Continuous cutting experiments of steel 45 were conducted to investigate cutting performance of TiB2/WC/h-BN micro/nano composite gradient self-lubricating ceramic tool. Influences of cutting speed on flank wear and tool life were analyzed. The results show that flank wear increases slightly when cutting speed V≥80 m/min, tool life increases initially and then decreases with increasing cutting speed. Wear mechanism was studied: the primary pattern of tool wear is abrasive wear and adhesive wear and solid-lubricants in tool have a noticeable wear-resistance effect during machining.
Influence of Temperature on the Preparation of GaN Nanowires
Authors: Wang Xin Zhong , Wu Cheng Guo , Li Shi Guo
Published: February 2014

As one-dimensional GaN material has excellent physical properties, it owns a huge prospect in the field of optoelectronic devices, and nanowire is currently one of the hotspots, at home and abroad, which had already invested a considerable force into the GaN nanowires. This paper studied the growth method based on Gas Liquid Solid (VLS) mechanism using Ni as catalyst in a chemical vapor deposition (CVD) system. By scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDX) spectroscopy, transmission electron microscopy (TEM) test, we focused on the influence of temperature and pretreat on the morphology and properties of GaN nanowires. At the same time, we explored the law and gave an appropriate explanation.
Powder Particles Grinder Mechanism Design and Exploration Tool
Authors: Xu Su Ying
Published: February 2014

The powder particles using the tool grinder is composed of two types . One is mounted on the rotating shaft of the machine tool . This tool is generally single cutting edge . The installation tool is a bolt shank fixed to the rotary shaft of the positioning groove . When you need to replace the tool mechanical enclosure open , loosen all bolts to remove the tool to replace the new tool . With no cutting edge tools can extend tool life. Reduce the number of replacement tools . The second tool is mounted on the housing of the machine tool . Single cutting edge of the tool mounting clearance is small, difficult to adjust the gap . Multi-blade cutter working gap can be formed when using the wedge mounting the inlet and outlet ports of the difference . Move the material in the resulting gap wedge and promote the formation of shear extrusion processing . Quick change fixed tool so that the tool sharp edge retention , reduce heat generation . Quick tool change involves cooling structure , the tool fixed way, the position of the discharge port design and rapid tool change .
Effect of Heat Treatments on Microstructure and Mechanical Properties of Low Carbon Steel Pipes Welded by Induction Process
Authors: Boumerzoug Zakaria , Lakhdari Lakhdar
Published: February 2014

In this work, the effect of isothermal heat treatments on microstructure evolution and mechanical properties after welding by induction of A37 pipeline steel have been studied by scanning electron microscopy, hardness measurements, and tensile tests. Microstructural evolution in welded joint was identified after isothermal annealing from 200 until 900 °C.
The Research on Ceramic Friction and Flow Stress of Plastic Forming
Authors: Liu Zhan Jun
Published: February 2014

The interface friction is used to evaluate the plastic flow behavior of workpiece material in different conditions such as temperature, pressure, strain rate and strain distribution. It is analyzed that deformation and material flow by the ring compression method during compression, which is contained with the theoretical calculation of different interface friction ring inside diameter and the height of the change. The progressive deformation incremental method is studied to the curve of the friction factor and ring size. It is given that the standard calibration curve of ring friction factor by 6:3:2 size ratio. According to the practical circle deformation ,it is given to the relative average stress, and then to calculate the average normal stress, according to the actual load stress ,it can be concluded that the actual flow stress of material. The change of ring height and diameter is measured by experiment. The results show that the friction factor is relatively stable, the maximum is 0.48, and then the minimum is 0.35.
Reliable Solvothermal Growth of Diverse Heterostructures Based on CdS Nanowires
Authors: Yang Fan , Yan Shan Cheng , Wang Bo Jun , Shuai Zhen Hua , Zhang Ming Xia
Published: February 2014

In the present study, the heterostructures of ZnO Nanoparticle (NP)/CdS nanowire (NW), SnO2NP/CdS NW, NiS NP/CdS NW, FeS NP/CdS NW, Ag2S NP/CdS NW, and Au NP/CdS NW have been successfully fabricated via the two-stage solvothermal process. Field-emission scan electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were adopted to characterize the as-prepared products. The optical properties of the as-obtained heterostructures were separately investigated. New insights into understanding and controlling the synthesis of different NW heterostructures are demonstrated in the reliable solvothermal route. We demonstrate that CdS NWs synthesized for 2h are the bifunctional mediator acting as catalyst or active spot for the growth of NW heterostructures Furthermore, understanding and controlling this phenomenon is a great asset for the realization of the formation mechanism of the NW heterostructures and opens up new ways toward for construction of other semiconductor heterostructures with novel properties.
Hydrothermal Synthesis and Visible-Light-Driven Photocatalytic Activities of Bi2WO6 Uniform Hierarchical Microspheres
Authors: Lan Yan , Wang Xiong
Published: February 2014

The microsphere Bi2WO6has been synthesized by a facile hydrothermal method by using Bi (NO3)35H2O, H40N10O41W125H2O and CO(NH2)2(urea) as the starting materials. The as-synthesized Bi2WO6was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM),BET and UV-vis absorption spectroscopy. The visible-light-responsive photocatalytic activity of Bi2WO6microspheres was evaluated by the photo-degradation of RhB under Xe lamp irradiation. The degradation is up to 96% in 3h. The results show that microsphere Bi2WO6exhibited excellent photocatalytic activity. The reasons for the high photocatalytic activity have been discussed carefully.
On the Damping Properties of a Polyurea Elastomer
Authors: Ghezzo Fabrizia , Miao Xi Geng , Ji Chun Lin , Liu Ruo Peng
Published: February 2014

The development of materials with high damping and energy absorption properties in the form of bulk materials or coatings is today a target for designing components and structures with improved durability and survivability to serve in fields such as aeronautical, mechanical, civil and environmental engineering. This paper presents the results of the dynamic mechanical characterization conducted on reinforced polyurea composites. The mechanical properties of two types of composite materials utilizing the polyurea elastomer as a matrix are compared with those of the pure polymer. The composite materials show a substantial increase of the damping ability. Such materials can be produced in the form of coatings and successfully applied for maximizing the damping of mechanical and structural vibrations or for limiting the damage effects of impact events on structures and components.
Microstructure Observation of the Tensile Fractured 430 Ferritic Stainless Steel
Authors: Zang Shu Jun , Li Juan Juan , Yin Xiao Qiang , Zhang Jian Bin
Published: February 2014

The article studies on sections microstructure of 430ferritic stainless steel after tension, the tensile temperatures are the 1073K, 1173K, 1223K, 1273K, 1323K and 1423K. The transverse sections (vertical tensile direction) of fractured specimens microstructure of 430ferritic stainless steel were observed and compared with those of longitudinal sections (parallel tensile direction). Moreover, we compare microstructure of transverse section specimens with the salt water-cooled condition and air-cooled condition. The optical micrograph of fractured tensile specimens of 430stainless steel after cooling to room temperature indicated that the volume fraction of the martensite is gradually increased and then declined from 1073K to 1423K. At 1223K, the martensite content is highest. At 1423K, martensite is sharply reduced and disappeared, the microstructure of 430ferritic stainless steel is almost all of ferrite and grain boundary obviously observed. Due to tensile deformation, the morphology of martensite is massive in the transverse section specimens. Whereas, the strip-type morphology of martensite was observed in the longitudinal section specimens. The cooling rate impact on the microstructure was also discussed.
Designing Q&P Process for Experimental Steel with 0.47 % Carbon Content
Authors: Pileček Vít , Jirková Hana , Mašek Bohuslav
Published: February 2014

The Q&P process (Quenching and Partitioning) is a heat treating method for high-strength low-alloyed steels. It delivers the desired combinations of high strength and adequate ductility. These properties are achieved thanks to the unique martensitic microstructure with a certain volume fraction of stable retained austenite. Retained austenite imparts plasticity to the otherwise brittle martensitic structure. Optimum mechanical properties are achieved by using correct processing parameters and chemistry of the material. The experimental material was a steel with 0.47 % carbon alloyed with silicon, manganese and chromium. The purpose of the effort was to optimise the heat treating parameters in order to obtain a strength level above 2000 MPa and an elongation of no less than 10%. In the first step, the appropriate austenitizing temperature was identified. In the second, effects of various quenching temperatures and cooling rates on the microstructure evolution were explored. In the third, the impact of raising the partitioning temperature on stabilization of retained austenite was examined. Adjustment of the parameters led to a strength of more than 2300 MPa and an elongation of 8 %.
Effect of Carbon Content in Direct Reduction Process of Limonite Iron Oxide to Produce Pig Iron Substitute for Thin Wall Ductile Iron Process
Authors: Soedarsono Johny Wahyuadi , Astini Vita , Fazri Fahmi , Kawigraha Adji , Sulamet-Ariobimo Rianti Dewi , Rustandi Andi , Tjahyono Seto
Published: February 2014

Quality molten metal needed to produce thin wall ductile iron (TWDI). Pig iron, as the major base material to produce quality molten metal, due to its high price, has been change with scraps. The use of scrap as major base material associates with more cleaning and chemical composition adjustment. The ITmk3 technology in iron making has successfully produced iron nugget. Iron nugget can be use to substitute pig iron due to its quality that is comparable to pig iron but lower in price. This research conducted to see the effects of carbon content in producing iron nugget. Limonite iron ores used in this research are part of laterite rocks taken from Sebuku Island in South Kalimantan, Indonesia. Variation made to weight of carbon mixed with laterite. Heating temperatures of direct reduction process are 700°C, 900°C, and 1000°C. The process times are 10, 20, and 30 minutes. XRF used in analysing Fe content in laterite and XRD is used in analysing result of direct reduction process. The result shows that increasing carbon content to certain condition will increase the rate of gasification process during direct reduction. The increase of gasification rate will result to higher Fe formation.
Effect of Homogenization Annealing on Microstructure and Property of Cu-7.5Ni-5Sn Alloy
Authors: Liu Rui Qing , Yang Sheng Li , Huang Guo Ji , Zhong Qiang Qiang
Published: February 2014

The microstructure and properties of Cu-7.5Ni-5Sn alloy after homogenization treatment was investigated. The research results show that homogenization treatment can obviously eliminate dendritic segregation in Cu-7.5Ni-5Sn alloy. The temperature of homogenization annealing has a great influence than the effect of holding time. The ingots of Cu-7.5Ni-5Sn alloy which were homogenization treated at 780°C for 24 hours can be rolled up to 30% deformation by cold-rolling. Some tiny white matter is still remaining in dendrite boundary, but atom fraction of Ni and Sn of the dendritic segregation is decreased by 12.04% and 4.73% respectively compare with casting state. The electrical conductivity and Brinell hardness of Cu-7.5Ni-5Sn alloy homogenization treated at 800°C for 24 hours is 12.8%IACS and 132Hv, and increases 18.5% and 29.9% respectively.
Characterization on the Microstructures and Optical Performances of TiO2 Doped with Transition Metals
Authors: Liu Xin Hua , Deng Yi , Zhang Yu Chuan , Zhou Yin Hang
Published: February 2014

The structures and optical performances of TiO2doped with 4thperiodic transition metal ions were investigated in this paper. The characterization results of X-ray photoelectron spectroscopy and X-ray diffraction showed that the transition metal ions existed in oxidative states, and composites formed because of the reaction between doped metal ions and TiO2. The absorption spectroscopy of TiO2doped with zinc was mainly in ultraviolet region, close to that of the pure TiO2. While for TiO2doped with other transition metal ions including V, Cr, Mn, Fe, Co, Ni and Cu ions, the absorption spectroscopies covered ultraviolet region and visible light region, much broader than that of the pure TiO2.
Numerical Analysis of Residual Stresses in Quenched High-Strength Aluminum Alloy Ultra-Thick Plates and their Reduction through Single-Side Cold Compression Method
Authors: Liu Jia Chen , Wang Jin Liang , Chen Hui Qin
Published: February 2014

Residual stresses developed after quenching of high-strength aluminum alloy ultra-thick plates have an important effect on the quality and reliability of parts, and should be reduction to meet the requirement. In this investigation, numerical techniques of SIMUFACT software are used to simulate residual stresses in quenched 340mm×127mm×124mm Al-Zn-Mg-Cu high-strength aluminum alloy ultra-thick plate, and the results have been verified. On the basis of verified simulation parameters, residual stresses in quenched 4000mm×720mm×285mm ultra-thick plate and their reduction through single-side cold compression method were simulated by SIMUFACT software. After quenching, the value of maximum tension stress located at the interior center of the plate is 200MPa, and the value of maximum compression stress located on the surface of the plate is-169MPa. Through analysis of single-side cold compression processes, it can be concluded that more than 90% quenching residual stresses can be reduced by 1% upsetting ratio and 75% feed of the top die. Residual stresses after compression can be reduced down to the range of-25~9MPa. Mean residual stress values of simulation after compression are identical to the XRD testing data.
Investigation on p-In0.51Ga0.49As LOPC Mode by Raman Spectra
Authors: Gao Han Chao , Yin Zhi Jun , Huang Zi Qian , Li Zhong Hui , Xie Zi Li
Published: February 2014

Heavily P type In0.51Ga0.49As was grown with hole concentration from 3.3E19cm-3 to 4.6E19cm-3. Standard (001) surface Raman backscattering geometry was used to measure samples. Two mode behavior and LO phonon-plasmon-coupled mode (LOPC) were observed obviously. Raman peak of LOPC mode is insensitive to hole concentration. The full width at half maximum (FWHM) of LOPC and the intensity ratio of GaAs-like LO mode and LOPC mode depend on hole concentration. The coupling strength of GaAs-like LO mode and plasmons is weak when hole concentration is very high and Raman peak of LOPC mode is independence with increasing hole concentration.
Growth and Spectrum Properties of Ho:BaY2F8 Crystal
Authors: Zeng Fan Ming , Li Chun , Lin Hai , Zhou Yan Yan , Liang Xuan , Fang Xu Guang , Liu He , Cui Ya Jun , Liu Jing He
Published: February 2014

Ho3+:BaY2F8(Ho:BYF) single crystal was grown by the Czochralski method. The optimal technical parameters obtained are as follows: the pulling rate is 0.5mm/h, the rotation rate is 5rad/min, the cooling speed is 10°C/h.The result of XRD curve shows that as-grown Tm:BYF crystal belongs to the monoclinic system and space group C12/m1. The cell parameters calculated are a=0.642nm,b=1.03293nm,c=0.42621nm,β= 99.62o.The absorption and fluorescence spectra of the Ho:BYF crystal were measured.FWHM is 8 nm on 884 nm wavelength,absorption coefficient and absorption cross-section calculated are 1.21cm-1and 1.21×10-21cm2.
Epitaxial Growth of SiC Epilayers for 10kV Schottky Diodes Using Chloride-Based CVD
Authors: Li Yun , Zhao Zhi Fei , Li Zhong Hui
Published: February 2014

A 100μm silicon carbide epilayer with mean doping concentration 6×1014 cm-3 was achieved on 3 inch silicon carbide substrate using a growh rate of 30 μm/h. Hydrogen gas foil rotation was adopted to improve the doping uniformity. The intra-wafer thickness and doping uniformity was 1.83% and 7.51%, respectively. Schottky diodes fabricated on this epilayer presented a breakdown voltage of 10kV. This is the first report of 10kV schottky diodes fabricated on silicon carbide epilayer made in China.
Microstructure and Compound Developed from the Ce-As-Fe at 1173K
Authors: Zhu Si Si , Zhang Jin Zhu , Yang Wei Yu
Published: February 2014

In this study, a certain amount of Cerium and Arsenic were closed in the barrel-shaped cylinder machined by H08 steel, heated to 1173 K for 50 h, and the interaction among the cerium, arsenic and iron in the barrel-shaped cylinder was studied by X-ray diffraction, optical microscopy and electronic probe microscopy analysis. The result shows that the gray phase is the ternary compound Ce12Fe57.5As41, and the ternary compound Ce12Fe57.5As41 is the main interaction product when the atomic ratio of Ce to As is 1:3. The eutectic compound Fe2As can be precipitated from ferrite with the temperature decreasing.
Current Situation of the Study on Oxidative Stability of Biodiesel
Authors: Ni Hong Jun , Chen Lei , She De Qin , Yuan Yin Nan
Published: February 2014

As a high quality alternative of fossil diesel, biodiesel is widely concerned at domestic and abroad for its environmentally friendly and renewable. Oxidation stability is one of the important properties of biodiesel, which is also one of the quality criteria in storing and using. The oxidative mechanism and the influencing factors of Oxidation stability, oxidation stabilitys evaluation methods and the application of biodiesel antioxidants were reviewed. Then the direction of oxidation stability is put forward.
The Study on Oxidation Resistance of SiC Composites Used for Solar Absorber Coating
Authors: Xu Xiao Hong , Rao Zheng Gang , Wu Jian Feng
Published: February 2014

The SiC composites with good oxidation resistance were fabricated via semi-dry pressing and pressureless firing in the air. The SiC, talc, kaolin, alumina, BN and H3BO3were used as starting materials. Sample B2 fired at 1280 °C had the optimal physical properties with a bending strength of 85.84 MPa. Sample B3 contained 1 wt% H3BO3and fired at 1300 °C for 2 h had the best oxidation resistance. After oxidized at 1000 °C for 50 h, the weight gain and oxidation rate constant of sample B3 were 3.3990 mg/cm2and 0.52×10-4g2/(cm4·s) respectively. The oxidation products of SiC, BN and H3BO3could generate SiO2-B2O3film and improve the oxidation resistance effectively. It is believed that these SiC composites should be a promising candidate in solar absorber coating.
Influence of Activated Carbon to the Hydrogen Storage Characteristics of THF Hydrate
Authors: Fang Ya Jun , Xie Ying Ming , Zhou Xing Fa , Yan Lin , Wang Shu Hao
Published: February 2014

High pressure hydrate experiment device was used to research the influence of active carbon to the hydrogen storage characteristics of THF hydrates in volume 502.4 ml and 1°C. The results show that within the experimental pressure range, the induction time changes irregularly, so active carbon has no apparent effect on the induction time, but has obvious influence to the pressure drop, under same initial pressure, the pressure drops with activated carbon are larger than that without activated carbon; With activated carbon, the higher the initial pressure the larger the pressure drop. Because the pressure drop is proportional to the hydrogen storage density, so the larger the pressure drop, the higher the hydrogen storage density. When the initial pressure is 8.4 MPa, with activated carbon the hydrogen storage density (0.0082wt%) is far higher than that (0.0031wt%) without it. So activated carbon can promote the hydrogen storage density of THF hydrate.
Kinetics Studies on Chemical Reaction of Producing Biodiesel Based on Transesterification
Authors: Wei Yi , Zhang Jing , Zhang Mu , Zhang Yin Dong
Published: February 2014

Orthogonal experiment of producing biodiesel needs to collect large volume of experimental data. In order to save time, factors which influence the yield of biodiesel were analyzed by combining Mass Action Law with Arrhenius equation and the reaction rate equation of biodiesel yield was determined when esterification reactions go along with the same amount of catalyst. At the same time, it provides the theoretical guidance to obtain the optimum reaction conditions.
Antibacterial Activity of the Extracts from Gentiana farreri Balf. f.
Authors: Yang Ai Mei , Shi Xiao Long , Sun Jing , Yang Lin , Men Yun
Published: February 2014

The antibacterial activity of extracts from Gentiana farreri Balf. f. was studied using Bnfillus licheniformis, Aeruginosus Bacillus, Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli as the test bacteria by Oxford cup. Meanwhile, the MIC of each extraction part of the ethanol extracts were determined. The results showed that the EtOAc extracts displayed the best antibacterial activity, the n-BuOH extracts had the lower activity, and the petroleum ether extracts had the lowest activity. The antibacterial activity enhanced along with the increase of sample concentration.
A Preliminary Study of Crosslinked Alginate-Chitosan Microspheres for Delivery System
Authors: Zhou Jie , Cui Yuan Lu , Qi Yun
Published: February 2014

Glutaraldehyde cross-linked chitosan coated-alginate microspheres were prepared to improve site specificity in colonic drug delivery system. Microspheres were characterized by microscopic image analysis, DSC and IR to study the formation of microspheres structure as well as the chemical interactions between drug and polymer. Microscope observation showed good spherical and homogeneous of microspheres. The glutaraldehyde cross-linked microspheres could produce Schiff base reaction and decrease chitosan hydrogen bonding interaction with mucous membrane. The drug loading of chitosan coated-alginate microspheres reached 43% and in vitro release properties of microspheres without cecal contents reached 20.96% after 12 h. The release profiles indicated that microsphere has a satisfactory sustained release behavior. Glutaraldehyde cross-linked chitosan coated-alginate microspheres have a great potential use in drug delivery system.
AMPK and Metabolisms of Glucose and Lipid
Authors: Chang Ying , Jiang Xin , Wang Yan Chun
Published: February 2014

AMPK is ubiquitous in eukaryotes.It takes part in cells metabolism and is called energy receptor.It is activated with AMP/ATP ratio increasing.At present,metformin is used to activate AMPK in order to regulate glucose metabolism and treat diabetes.In this article,we summarize the structure activity of AMPK and its effects on glucose and lipid metabolism.
Comparison of Physicochemical Properties of Gelatins Prepared from Different Fish Skins through Hot Water Extraction at Mild Temperature Condition
Authors: Jiang Yu , Yu Jun , Liu Cheng Chu
Published: February 2014

Gelatins were prepared from tilapia, salmon and halibut skin through hot water extraction (60°C, 180 min) and their physiochemical properties were compared with commercial gelatins from porcine and bovine sources. Tilapia gelatin contained highest hydroxyproline content (8.45%) and had highest gel strength (376.6 g), followed by salmon gelatin. Halibut gelatin had the lowest hydroxyproline content (24.72% in average) and gel strength (47.56 g in average). Gelatin prepared from tilapia had much higher gel strength and viscosity than commercial pharmaceutical gelatins of porcine and bovine sources and showed a great potential to be utilized in pharmaceutical industry.
Analysis of Composites for Best Designs of Refractive Solar Concentrators
Authors: Pérez Calero José Ignacio
Published: February 2014

This Paper studies the important role of the Composites, in the complex process of designing Solar Refractive Concentrators, that would be unthinkable and unrealizable without their employment, when having necessary the technical characteristics that they make them viable. It contributes, also, the methodologies followed for the accomplishment of optimal prototypes, by means of Numeric Methods of simulation (Finite Elements), experimental on models and of characterization of composite laminates.
The Development of the Multi-Functional Wool/Aramid 1313 Blended Fabric
Authors: Zhang Hui , Shen Lan Ping
Published: February 2014

The wool and aramid 1313 blended yarn by ratio of 80/20 was introduced. The 2/1 twill and 11-heddle double satin were selected. Then the high hydraulic pressure infiltration finishing and the dry cloth impact finishing were done. By carrying on the comprehensive performance test, two kinds of multi-functional fabric used in spring-summer and autumn-winter were developed. It provides a scientific basis for the further development of flame-retardant fabric with medium and high grade, and has a positive significance for its design and production in textile.
Application of Ferritin Modified Eggshell Membrane in Heavy Metal Ion Uptake and Recovery
Authors: Zhang Tuo , Zang Jia Chen , Zhang Sheng Li , Zhao Guang Hua
Published: February 2014

A ferritin mutant A1C with 24 free SH groups on its outer surface was prepared, which was successfully cross-linked to hen eggshell membrane outer layer (ESM-OL) by a disulfide linkage as characterized by SEM and TEM. Generally, this ferritin conjugated ESM-OL (Ft-ESM-OL) exhibited a significantly higher activity of heavy metal ion uptake as compared to ESM-OL alone under the same experimental conditions. For example, the adsorption capacity of Ft-ESM-OL for U6+ and Fe2+ were 21.16% and 18.4% higher than that of natural ESM-OL, respectively. On the other hand, the recovery capacity of Fe2+ by Ft-ESM-OL was 8.11 mg/g ESM, a value 67.9% higher than that of natural ESM-OL. Thus, this newly ferritin-modified ESM-OL greatly improved the adsorption and recovery efficiency of heavy metal ion as compared to ESM-OL alone.
Preparation and Antioxidant Activities of Peanut (Arachin conarachin L.) Protein Peptides by Bacillus Subtilis Solid State Fermentation Method
Authors: Yu Li Na , Feng Jian Xiong , Ming Qiang Qiang , Yang Qing Li , Zhang Chu Shu , Sun Jie , Bi Jie
Published: February 2014

The objective of this work is to study on preparation of peanut protein peptide by bacillus subtilis solid state fermentation method. Results indicated that soluble nitrogen concentration of protein peptide could reach 122.86mg/mL, 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) and hydroxyl free radicals scavenging rates were 85.22% and 84.88%, respectively, under the following optimum conditions: nutrient salt solution of 16.3mL, bacterial suspension volume of 3.8mL, temperature of 45°C, and time of 41h. IC50values for scavenging of DPPH, hydroxyl and superoxide anion free radicals rates, iron and copper ion chelating rates, inhibition rate of anti-lipid peroxidation were 2.88mg/mL, 4.63mg/mL, 1.22mg/mL, 0.04mg/mL, 0.94mg/mL, 3.78mg/mL, respectively. When absorbance value of iron and molybdenum reduction capacities was 0.5, the required protein peptide concentrations were 7.28mg/mL and 1.85mg/mL, respectively.
Experimental Investigation into Spall of Carbon Phenolic Composites
Authors: Zhu Zhi Gang , Li Yong Chi
Published: February 2014

The velocity history of free-surface particle for carbon phenolic composites (density is 1.4g/cm3) is obtained based on the loading technology of the light gas gun, the relationship between the striking velocity of flyer and the spall thickness as well as time is investigated. Besides, spall strength and thickness are obtained by analyzing the samples data and curves. The high pressure physical characteristics, such as type Hugoniot curve and Murnagham state equation for this material, are acquired by analyzing the velocity history of free-surface and spall characteristics. This study provides a methodology to quantify spall and physical characteristics for carbon phenolic composites under tensile wave loading.
Function and Application of Calixarene Derivatives
Authors: Tan Ri Hong
Published: February 2014

Calixarene is the third generation of the main compound. Its molecular recognition, simulation enzyme catalysis, molecular catalysis, analytical chemistry, self-assembly, and other areas of research have made great progress. calixarene represent a well-known family of macrocyclic molecules with broad range of potential applications in engineering materials fields. calixarene derivatives for simulating biological system, or in the form of new drug molecules targeting molecule reaction vessel, molecular switches, etc.; Under certain conditions because some new calixarene derivatives with the liquid crystal properties, so some new type of liquid crystal materials can be screened and prepared.
Controllable Preparation Cu2O/AC and Application in Photocatalytic Degradation of Organic Dyes
Authors: Wang Zhen Wei , Guo YaJie , Kang Fang Fang , Cao Qing Xi , Wang Guang Jian
Published: February 2014

The Cu2O supported by active carbon (Cu2O/AC) was prepared by impregnation with different concentrations of CuSO4 and Na2SO3 in HAc-NaAc buffer solution. The addition of a few C6H12O6 (glucose) in reaction favored of improving the quality of the cuprous oxide. The sample was characterized by chemistry analysis, SEM, XRD and so on. The results showed that the cuprous oxide was of pure phase and radial spherical morphology. The photocatalytic activity of prepared catalysts was investigated for degradation of organic dyes. The degradation efficiency was up to 95% under the optimized experimental conditions.
Polymerization and Chiroptical Behavior of Polymethacrylamides Bearing a Bulky Oxazoline Pendant
Authors: Fu Zheng , Wei Hong , Yuan Chao , Li Zhong Wen
Published: February 2014

The radical polymerization of optically active methacrylamide derivatives, N-[o-(4-phenyl-4,5-dihydro-1,3-oxazol-2-yl) phenymethacrylamide ((R)-PhOPMAM) and N-[o-(4-isopropyl-4,5-dihydro-1,3-oxazol-2-yl) phenymethacrylamide ((S)-PriOPMAM), were carried out under various conditions. The effect of the Lewis acid, that is, rare earth metal trifluoromethanesulfonates on the free-radical polymerization were examined under different solvents. The Lewis acids are effective in enhancing the isotacticity in the polymerization of (S)-PriOPMAM. The same phenomenon were not happened in the polymerization of (R)-PhOPMAM. The polymerization characteristics and the chiroptical behavior of the resultant polymers have been examined by using circular dichroism (CD), UVVis, and NMR spectroscopies.
Study on the Prepartion of Slag Haycite for Phosphorus Removal Using Ammonium Hydrogen Carbonate as Pore Former
Authors: Li Xue Lian , Liu Xiao , Cao Guo Ping
Published: February 2014

Porous slag haycite for phosphorus removal was made from slag, as the main raw material, clay, as binder, and ammonium hydrogen carbonate, as a pore forming agent. And the influence of material ratio and sintering condition were investigated. The best ratio of steel slag: Clay: ammonium hydrogen carbonate was 53.5%:42.5%:4% as ascertained, and the best sintering temperature 800°C, sintering time 60min. The porosity of slag haycite was 2 times more than original slag, and the specific surface area was increased evidently, thus very conducive to microbial growth.