bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Molecular Weight Molecules of Oyster Nacre Induce Mineralization of the MC3T3-E1 Cells
Authors: Rousseau Marthe , Boulzaguet Helene , Biagianti Julie , Duplat Denis , Milet Christian , Lopez Evelyne , Bedouet Laurent
Published: March 2009

The nacre layer from the pearl oyster shell is considered as a promising osteoinductive
biomaterial. Nacre contains one or more signal molecules capable of stimulating bone formation.
The identity and the mode of action of these molecules on the osteoblast differentiation were
analyzed.
Water-soluble molecules from nacre were fractionated according to dialysis, solvent extraction and
reversed-phase HPLC. The activity of a fraction composed of low molecular weight molecules in
the mineralization of the MC3T3-E1 extracellular matrix was investigated. Mineralization of the
preosteoblast cells was monitored according to alizarin red staining, Raman spectroscopy, scanning
electron microscopy and quantitative RT-PCR.
Molecules isolated from nacre, ranging from 50 to 235 Da, induced a red alizarin staining of the
preosteoblasts extracellular matrix after 16 days of culture. Raman spectroscopy demonstrated the
presence of hydroxyapatite in samples treated with these molecules. Scanning electron microscopy
pictures showed at the surface of the treated cells the occurence of clusters of spherical particles
ressembling to hydroxyapatite. The treatment of cells with nacre molecules accelerated expression
of collagen I and increased the mRNA expression of Runx2 and osteopontin.
This study indicated that the nacre molecules efficient in bone cell differentiation are certainly
different from proteins, and could be useful for in vivo bone repair.
Effect of Ionic Exchange on Osteoblast Behaviour on Bioactive Tissue Engineering Substrates
Authors: del Valle Sergio , Engel Elisabeth , Braak S. , Planell Josep A. , Ginebra M.P.
Published: March 2009

In this work we examine the effect of the ionic exchange in cell behaviour of two apatite
substrates with the same chemical composition but different microstructures (Coarse and Fine) by
culturing cells with their extracts. A higher decrease in Ca and a higher increase in P concentrations
were detected in the culture medium extracts from the finer apatite substrate in accordance with its
higher specific surface area. A decrease in cell proliferation was observed when cells were cultured
with the Fine extract in comparison with cells in contact with the Coarse extract or the control
group. Although the higher ionic exchange, this could not explain the drastic decrease in cell
proliferation observed on Fine apatite substrates, so a strong interaction with the underlying
microstructure that modulates cell behaviour is also present.
Expression of ODF and ICAM-1 of Bone Marrow Mesenchymal Stem Cells is Enhanced with Osteogenic Differentiation
Authors: Wang Jun , Fan Yu Bo , Zhao Zhi He , Li Juan , Liu Jun
Published: March 2009

Osteoblasts were perceived as pivotal cells, recognized as the cells that control both the formative and the resorptive phases of the bone remodeling cycle. Osteoblasts were an essential requirement for osteoclastogenesis though expressing or secreating bioactive osteoclast-differentiation-regulatory proteins, osteoclast differentiation factor (ODF)was the most important factor among these, ODF participate nearly in every step of differentiation and activation of osteoclasts. In addition, intercellular adhesion molecule-1 (ICAM-1)and its receptors LFA-1 play a role in osteoclast development by affecting adhesion between stromal cells and osteoclast progenitors before the occurrence of ODF-ODF receptor signaling. However, it is not clear about the relationship between ODF, ICAM-1 expression of osteoblasts and differentiation state of osteoblasts. So,the aim of this study was to investgate whether the expression of ODF, ICAM-1 depended on the stage of osteoblastic differentiation from rat bone marrow mesenchymal stem cells(rBMSCs). The viability of rBMSCs is reduced significantly by osteogenic inducement as differentiating into osteoblasts, ALPase activity of OS-treated rBMSCs was enhanced obviously within 9 days , declined subsequently and recovered nearly the original level at day 14. Expression of ODF is enhanced with osteogenic differentiation guadully. whereas, expression of ICAM-1 is activated at OS-treated day 6, then keeping at a stable level. This study indicated that rBMSCs undergoing osteogenic inducement was an ideal model for studying the differentiation and maturation of osteoblasts. During the early stage of differentiation along osteoblasts from stem cells to osteocytes, rBMSCs or Osteoprogenitor react somewhat differently from osteoblasts, suggesting the ability of osteoblasts to regulating differentiation and maturation of osteoclasts have been improved with osteogenic culture.
Bone Ingrowth for Sinus Lift Augmentation with Micro Macroporous Biphasic Calcium Human Cases Evaluation Using MicroCT and Histomorphometry
Authors: Mailhac N. , Daculsi G.
Published: March 2009

The development of implantology requires enough bone support, sufficient bone
architecture. The use of autograft remains the gold standard; however the surgeons use cortical bone
coming from mandibular part or craniofacial site, involving severe anaesthetic bone loss. The
strategy of bone substitutes in place of autograft can be an efficient method. Several patients having
a sinus lift augmentation using MBCP, and BioOss have been performed in human, and bone
biopsies were realized during the preparation of the site for dental implantation. Biopsies were
analyzed in classical histology without decalcification and by 3D reconstruction using micro CT.
Both techniques revealed bone ingrowth and MBCP resorption. For BioOss, no bone ingrtowth and
resorption process were observed in spite of stability of the implant and clinical efficiency. These
case reports confirm the performance of bone substitutes for Sinus Lift augmentation.
Qualitative and Quantitative Evaluation of Bone and Synthetic Calcium Phosphates Using Raman Spectroscopy
Authors: Numata Yasuko , Sakae Toshiro , Suwa Taketoshi , Nakada Hiroshi , LeGeros Racquel Z. , Kobayashi Kihei
Published: March 2009

The purpose of this study was to evaluate synthetic calcium phosphates and animal bones using
Raman spectroscopy and explore the possibility of its application in characterizing newly formed bone around
implants. Synthetic calcium phosphates (monobasic calcium phosphate, dibasic calcium phosphate, tribasic
calcium phosphate, fiber apatite, hydroxyapatite and carbonate hydroxyapatite) and animal bones (from pig,
cow, rabbit with and without implants) were analyzed in this study. Slight differences in the Raman bands
among the 7 types of synthetic calcium phosphate were observed. Furthermore, a 3 cm-1 difference was noted in
the bands of the main PO4
3- in rabbit’s bone formed around the implant, compared to the existing bone,
suggesting a difference in the molecular structure between the existing and newly formed bones.
Effect of Mg2+ Addition during HA Nanoparticles Synthesis Using Ultrasonic Irradiation
Authors: Gouveia D.S. , Rumbao Ana Carolina S. Coutinho , Bressiani Ana Helena A. , Bressiani José Carlos
Published: March 2009

Nanocrystalline hydroxyapatite was prepared by a precipitation method with add of ultrasonic
irradiation. In this work the effect of H3PO4 addition rate during synthesis and the influence of
the magnesium incorporation into apatite were studded. The results revealed that the morphology
and cristalinity of synthesized nanopowders are significantly affected by ultrasonic irradiation. Monophase
hydroxyapatite was obtained when magnesium was added into HA lattice during the synthesis
with ultrasonic irradiation.
In Vitro Behavior of Fiber Bundles and Particles of Bioactive Glasses
Authors: Zhang Di , Arstila Hanna , Vedel Erik , Ylänen Heimo O. , Hupa Leena , Hupa Mikko
Published: March 2009

In vitro reactions of bundles of fibers with diameters 20-500 μm and crushed glasses of
fractions 500-800 μm were compared with the reactions of plates of the same bioactive glasses. The
samples were immersed in simulated body fluid (SBF) for 2-7 days. After immersion the changes
on the surfaces of the samples were observed by SEM/EDXA. Layer formation on the glass surface
was found to vary with glass composition, sample shape and local condition of single particle/fiber.
However, only some fibers or particles formed similar in vitro reaction layers as the plates. The
product form did not change the in vitro bioactivity of particles or fibers exposed to the bulk
immersion solution. When the glasses were used as fiber bundles or particle beds, the packing
degree and the flow of body fluids within the system interfered with the reactivity. Also a clear
correlation between in vivo layer formation in bone and in vitro of the glass plates could be found.
Preparation of a Novel Poly(Methyl Methacrylate)-Dimethyl Diethoxysilane Nano-Composite
Authors: Lee Kyu Hyeon , Lee Yong Keun , Lim Bum Soon , Cho Sung Baek , Rhee Sang Hoon
Published: March 2009

The poly(methyl methacrylate)/silica nano-composite made from trimethoxysilyl
functionalized poly(methyl methacrylate) and dimethyl diethoxysilane was newly prepared and its
apatite-forming ability and mechanical properties were evaluated comparing to poly(methyl
methacrylate)/silica nano-composite made from trimethoxysilyl functionalized poly(methyl
methacrylate) and tetraethyl orthosilicate. Its apatite-forming ability was similar to that of
poly(methyl methacrylate)/silica nano-composite using tetraethyl orthosilicate but its fracture
toughness was much improved. Its high fracture toughness might come from the less quantity of
siloxane linkages in its structure because dimethyl diethoxysilane had only two ethoxysilane groups
while tetraethyl orthosilicate had four ethoxysilane groups. From the results, it can be concluded that
it has a possibility to be used as bioactive bone cement.
Effect of a Silane Coupling Agent on Mechanical Properties of Hydroxyapatite/Polycaprolactone Composites
Authors: Yang X.B. , Lu X. , Ge J.J. , Weng Jie
Published: March 2009

Silanization of hydroxyapatite was employed to improve the bonding between
hydroxyapatite and polycaprolactone. FTIR of HA after silanization showed that new peaks
attributed to silane do exist. The increase of melting and crystallization temperatures of silaned
composites shown from DSC implied that there exists much stronger bonding between PCL and
silaned HA particles. Fracture surface of composites after tensile testing observed by using SEM
showed that silaned HA particles dispersed much evenly and coalesced compactly in PCL matrix,
suggesting that silaned HA particles had good compatibility with PCL. The tensile strength and
modulus increased from 16.81 MPa and 239.21 MPa to 20.49 MPa and 539.57 MPa, respectively.
Development of Bioactive Titanium-Apatite Nuclei Composite
Authors: Yabutsuka Takeshi , Hibino Mitsuhiro , Yao Takeshi
Published: March 2009

Apatite nuclei were precipitated in the pores of titanium in simulated body fluid (SBF)
and titanium-apatite nuclei composite was obtained. Apatite was induced by the apatite nuclei
inside the pores of the composite and apatite layer was formed on the composite surface by soaking
in SBF. The apatite layer showed high adhesive strength to the composite due to a mechanical
interlocking effect between the composite and the apatite.
Effect of Oxidation Pressure on Controlling Octacalcium Phosphate Nucleation on Implant Titanium by ECR Plasma Oxidation
Authors: Orii Yusuke , Masumoto Hiroshi , Goto Takashi , Honda Yoshitomo , Anada Takahisa , Sasaki Keiichi , Suzuki Osamu
Published: March 2009

The surface oxide films were prepared by Electron Cyclotron Resonance (ECR)
plasma oxidation on Ti substrates. Octacalcium phosphate (OCP) and dicalcium phosphate
dihydrate (DCPD) peaks were formed after calcification by supersaturated calcium and
phosphate solutions. Calcification ability was enhanced with increasing the oxidation time and
the total pressure of ECR plasma treatment during oxidation. The results demonstrated that the
calcium phosphate nucleation and the deposition can be controlled by various ECR plasma
conditions.
Processing and Characterization of Apatite-Wollastonite Porous Scaffolds for Bone Tissue Engineering
Authors: Wood David J. , Dyson J. , Xiao K. , Dalgarno Kenny W. , Genever P.
Published: March 2009

There is a clinical and socio-economic need to produce synthetic alternatives to autologous or allogenic bone grafts. Bioactive glasses and glass-ceramics offer great potential in this area. The aims of this study were to optimise production of apatite-wollastonite (A-W) glassceramic scaffolds produced by selective laser sintering, in terms of their physical and biological properties and to look at how human Mesenchymal Stem Cells (MSCs) responded to these 3-D scaffolds in vitro. An indirect selective laser sintering process successfully produced strong, porous scaffolds. Depending upon particle size(s) and infiltration of the porous structure, flexural strengths between 35 MPa and 100 MPa were obtained. Following static seeding of A-W scaffolds with MSCs, fluoresecent actin and nuclei staining, as observed by confocal microscopy, showed that these scaffolds supported the adherence of human MSC’s at time periods of up to 21 days. As such these seeded scaffolds show great potential for use in bone regenerative medicine.
Characterization of the Calcium Phosphate Porous Ceramic Obtained by Foam Consolidation Using Albumin
Authors: Ribeiro Christiane , Bressiani José Carlos , Bressiani Ana Helena A.
Published: March 2009

In many in-vivo and in vitro studies, the behavior of calcium phosphate ceramics like β -
tricalcium phosphate in biological environments has been reported to be predictive and positive. In
terms of bone tissue growth, this ceramic can be more attractive presenting a porous microstructure.
To obtain biomaterial quality ceramics, in this investigation β- TCP porous ceramics were prepared
by a special consolidation method with albumin as a foam generating agent. This technique enables
preparation a variety of formats with complex geometries. To obtain porous samples using albumin,
heat had to be introduced into the system during the consolidation stage. After consolidation, the
samples were sintered at 1250oC for 30 minutes and characterized using X-ray diffractometry,
scanning electron microscopy and mercury porosimetry. The foams that were obtained by this
method exhibited spherical and interconnected pores, characteristics desirable in biomedical
implants.
Effects of Hydrothermal Treatment Temperature on the Crystallinity of Cancellous Bone Type Carbonate Apatite Foam
Authors: Wakae Hanae , Takeuchi Akari , Matsuya Shigeki , Munar Melvin L. , Nakagawa Masaharu , Udoh Koh-ichi , Nakashima Akihiko , Kunio Ishikawa
Published: March 2009

We have previously reported that the carbonate apatite (CAP) foam that has similarities in
both inorganic chemical composition and morphology to cancellous bone could be prepared from
α-tricalcium phosphate (α-TCP) foam by the hydrothermal treatment with Na2CO3 at 200°C for 24 hrs.
However, the crystallinity of the CAP foam was much higher than that of bone. In order to prepare
CAP foam similar to cancellous bone in crystallinity as well as its inorganic composition and
morphology, this study attempted to prepare CAP foam at lower temperature. Hydrothermal
treatment at 100°C allowed low-crystalline CAP foam whereas longer period was imposed for
complete conversion of α-TCP foam into CAP foam.
Dynamic Design for a Novel Parallel Kinematic Machine with Passive Linkage
Authors: Hu Ying , Li Bing , Su Dai Zhong , Hu Hong
Published: March 2009

Based on the proposed 4PUS-1RPU parallel mechanism a 5-axis Parallel Kinematic
Machine (PKM) scheme has been developed and the dynamic characteristics of the PKM have been
investigated in detail. To avoid the intensive computation caused by finite element analysis in the
research, two typical metamodeling techniques of Response Surface Methodology (RSM) and its
artificial neural network enhanced technique were employed as the robust design approaches.
Comparing the results obtained from the direct RSM the modeling accuracy by the artificial neural
network enhanced RSM can be improved.
A Novel Living-Cell Imaging System Design with Ultra-Long Working Distance and High Numerical Aperture
Authors: Huang Guo Liang , Dong Zhong Hua , Deng Cheng , Xu Shu Kuan , Zhu Jiang , Yang Xiao Yong , Jin Guo Fan
Published: March 2009

Microscopy is an important tool in biology and medicine, but it is often limited to optical
imaging structures with high numerical aperture(NA) with a short working distance(wd), for
example NA = 0.6 and wd <1 mm are usual. The common microscope objective is inadequate for
imaging of living cells in culture as an optical imaging structure with both high numerical aperture
and long working distance is required. In this study, a novel optical design has been developed to
meet the long working distance and high resolution power imaging of living cells in a vessel with a
high culture solution thickness, where cells need to be developed in about 48 hours or a week. The
developed optical design was characterized by an ultra-long working distance (wd >13.5 mm) and
high numerical aperture (NA = 0.7). This optical imaging system is not only good for the
subcellular imaging of free-floating cells in culture, but also for the imaging of cells attached at a
surface of vessel.
Fabrication of High Aspect Ratio Periodical Structure on Metal Using an Electroforming Process
Authors: Chuang Wei Ching , Chao Ching Kong , Chang Wen Chung , Ho Chi Ting
Published: March 2009

A procedure for fabricating a periodic structure on a metal at submicron order using holographic interferometry and molding processes is described. First, holographic interference using a He-Cd (325nm) laser is used to create the master of the periodic line structure on an i-line sub-micron positive photoresist film. A 200nm nickel thin film is then sputtered onto the positive photoresist. Pattern is then transferred to a metal using Nickel-Cobalt electroforming. Initial results show the technique can accurately control the grating’s period and depth.
The Analysis on Penetrating Efficiency in High-Energy Beam Drilling
Authors: Ho Je Ee , Young Hong Tsu
Published: March 2009

In Laser Beam (L.B.) and Electron Beam (E.B.) drilling, the energy distribution
significantly affects both the penetrating efficiency and working performance, both of which are
usually estimated by numerical skill or experimental measure. Through the application of a
stimulation model, an unstable solution with the finite difference method will result near the solidliquid
interface unless much finer grid sizes are set up. To improve on the above defect, nonuniform
grids are therefore utilized; this will complicate the built-up of the program and also easily
causes the simulated energy distribution to be divergent in the iteration process. In this study, an
estimated small Peclet number and observed narrow-deep cavity made the convective and radial
diffusion terms small enough to be neglected in the governing equation. From these assumptions,
the model was then used to investigate the drilling efficiency where two-phase flow convection
could be simplified further into one dimension and thus the analytical solution becomes possible by
transferring the penetration velocity into the logarithmic form. When compared with the experiment
made by Allmen [1] , the present model shows good agreement in higher energy density and
relative errors are no more than 10%.
Laser Patterning Indium Tin Oxide Thin Films on Glass Substrate
Authors: Chen Ming Fei , Chen Yu Pin , Hsiao Wen Tse , Gu Zhi Peng
Published: March 2009

Laser patterning technology of indium tin oxide thin films has been studied in this
research. ITO thin films, which usually coat on the glass and the plastic substrate, have been
adopted in the flat panel displays (FPDs) and the plasma display planes. The conventional method
of the ITO patterning usually uses the wet chemical etching processing. However, the wet etching
processing is not adopted in the plastic materials because the chemical fluid usually damages the
plastic substrate. The laser direct writing processing has been developed and replaces the wet
etching processing. This investigation is interested in the laser patterning used the third-harmonic
Nd:YAG laser (355 nm) to ablate the ITO films of glass substrate. The scanning electron
microscope (SEM) measures the characterization of the ablated grooves used the different
parameters, including the laser energy, the repetition rate and the feeding speed of the table. Finally,
the effect parameters of laser ablating ITO film will be presented in this paper.
The Design of an Atmospheric Pressure Plasma Torch Used for Polishing Ultra-Smooth Surfaces
Authors: Zhang Ju Fan , Wang Bo , Dong Shen
Published: March 2009

As there are always certain defects on the final surface of large-scale lightweight mirrors, which are formed in traditional mechanical polishing process, such as microcracks, lattice disturbances, plastic deformation, and so on, an atmospheric pressure plasma polishing method is a good solution to this problem. As a key component, the design of the capacitance coupling atmospheric pressure radio-frequency plasma torch is introduced. The designed torch uses water cooled coaxial aluminium electrodes with special treatment to avoid arcing between them. In normal machining process, the mixture of reaction gas and plasma gas with optimum ratio is input into the plasma torch. Then, excited by radio-frequency power, reaction gas is ionized in the plasma so as to create high density and energy reactive radicals under atmospheric pressure. The radicals cause chemical reactions with the atoms on the part surface, which performs an effective atomscale removal process. As the machining process is chemical in nature, this method avoids surface/subsurface defects mentioned above. Furthermore, initial experiment data analysis has proved that the atmospheric pressure plasma polishing method is effective and reliable, as well as demonstrates the validity of the designed plasma torch.
A Study on the Characteristics of Micro Deep Hole Machining Processes
Authors: Seo Tae Il , Kim Dong Woo , Cho Myeong Woo , Lee Eung Sug
Published: March 2009

Recently, the trends of industrial products move towards more miniaturization, variety
and mass production. Micro drilling which take high precision in cutting work is required to
perform more micro hole and high speed working. Especially, Micro deep hole drilling is becoming
more important in a wide spectrum of precision production industries, ranging from the production
of automotive fuel injection nozzle, watch and camera parts, medical needles, and thick multilayered
Printed Circuit Boards(PCB) that are demanded for very high density electric circuitry. The
industries of precision production require smaller holes, high aspect ratio and high speed working
for micro deep hole drilling. However the undesirable characteristics of micro drilling is the small
signal to noise ratios, wandering motion of drill, high aspect ratio and the increase of cutting force
as cutting depth increases. In order to optimize cutting conditions, an experimental study on the
characteristics of micro deep hole machining processes using a tool dynamometer was carried out.
And additionally, microscope with built-in an inspection monitor showed the relationship between
burr in workpieces and chip form of micro drill machining.
ELID Assisted Precision Conditioning of Coarse-Grained Diamond Grinding Wheel
Authors: Zhao Qing Liang , Brinksmeier Ekkard , Riemer Otmann , Rickens Kai
Published: March 2009

In order to realize ductile machining of optical glasses using mono-layer nickel
electroplated coarse-grained diamond grinding wheel, a novel conditioning technique features using
a copper bonded diamond grinding wheels of 15m grain size dressed by ELID (electrolytic inprocess
dressing) to condition the 46m grain sized diamond wheel has been developed. During the
conditioning process, a force transducer was used to monitor the conditioning force, a coaxial
optical distance measurement system was used to in-situ monitor the modified wheel surface status.
White-light interferometry (WLI), scanning electron microscopy (SEM) and atomic force
microscopy (AFM) were used to characterize the conditioned wheel surface status as well as the
ground optical glass surface topography correspondingly. The experimental result indicates that a
minimized wheel radial run-out error of less than 2μm as well as the top-flattened diamond grains
of constant wheel peripheral envelop profile were generated on a 5-axis ultra-precision machine
tool. The grinding experiment proved that the well conditioned 46μm coarse-grained diamond
wheel can be used in realizing the ductile grinding of optical glass BK7, which indicates that the
newly developed conditioning technique is feasible and applicable to introduce the coarse-grained
diamond wheels into precision machining of brittle and hard-to-machine materials.
Fabrication of Light Guide Plate on PDMS-Based Using MEMS Technique for Application of LED-Backlight
Authors: Chien Chao Heng , Chen Zhi Peng
Published: March 2009

Following the development of the thin-LCD, many researchers have improved the traditional backlighting module to make it thinner, lighter, and brighter which has already become the trend. The light guide plate is a very important component in backlighting module. Generally, the traditional light guide plate (LGP) is made of PMMA material. Injection molding technique is applied to fabricate the traditional LGP. In this research, Polydimethylsiloxane (PDMS) material was used to make the LGP, which was fabricated by using MEMS technique. In order to modify the traditional LGP, the micro prisms were constructed on the bottom surface of the PDMS LGP. Silicon mold was used to define the geometry of the micro-prism. Anisotropic etching technique was applied to fabricate the prism silicon mold. A liquid PDMS mixture was cast onto the prism silicon mold and the PDMS LGP was completed. White LED was utilized to be the light source of the PDMS LGP. After going through the illuminative test, PDMS LGP was demonstrated successfully of guide light function and its 77% of illuminative uniformity was achieved requirement of a general v-grooved light guide. The thickness of the PDMS LGP is easy to control and the PDMS is a heat-resistant and cheap material; therefore, the space and fabrication cost are saved. The field of MEMS has experienced rapid growth in the recent decade. In the future, the PDMS LGP can make displays thinner and brighter for thin-LCD applications.
Regular Dot Pattern of Light Guide Used in Liquid Crystal Display Backlight
Authors: Meng Xiao , Li Xiao Tong , Cen Zhao Feng , Deng Shi Tao
Published: March 2009

This paper proposes a backlight system that generates the regular dot pattern on the
bottom of light guide to achieve uniform luminance. The simulation program employs the variable
r-cut technique combined with some regular dot pattern such as shift-rectangular, hexagonal and so
on. The r-cut technique based on molecular-dynamic method, was first bought up to apply in the
random dot pattern. By using such a technology, we could easily evaluate the right range of radius
within each cell to get the general dot distribution according to the specific position away from light
sources and the sources properties, after we divided the total effective domain into several sections
of cells. In the end we made some fine-tuning on the boundaries to obtain the final result. It has
been revealed in the simulation that the light guide can achieve a uniformity of more than 90% and
optical efficiency about 26%. What we have more interest in are the optical properties that have
much influence on both the uniformity and the optical efficiency. Particularly when it comes to
larger size backlight products used in PC screen for instance, it will have a great impact. Several
figures in this paper also illustrate the dots distribution and the illuminance distribution.
Study on the Influence Factors of Electrochemical Micromachining
Authors: Wang Zhen Long , Zhu Bao Guo , Zeng Wei Liang , Sun Li Zhong
Published: March 2009

There are many influence factors of electrochemical micromachining (EMM)
development. So the characteristics of EMM technology were analyzed firstly. It was an effective
method that the nanosecond pulses voltage was used in EMM, and the nanosecond pulses voltage
was prepared to solve the problems of machining area, using small gap, and machining micro 3D
structure. Its minimum pulse duration is 5ns, and its voltage, current, and duty ratio can be changed
freely. Moreover, many experiments of EMM were carried into execution. After the phenomenon
and results of the experiments were analyzed, the reformative project of experiment was put
forward. The feasibility of the project and technique route was testified correctly by the nanosecond
pulses voltage on the multifunction machine tool which was manufactured independently. After
studying on the influences of EMM technology, the experiences of EMM process will be enriched
and make EMM have a further development.
Fabrication of Ti2AlC/TiAl Composites with the Addition of Niobium by Spark Plasma Sintering
Authors: Yue Yun Long , Wu H.T.
Published: March 2009

Ti2AlC/TiAl composites with the addition of niobium were prepared by spark plasma sintering
using titanium, aluminum, niobium elemental powers and TiC particles as reactants. The experimental
and analytical studies on this kind of material concentrated on the relationship between reinforcement
phase and mechanical properties. The Ti2AlC/TiAl composites with 5% niobium exhibit high mechanical
properties. The three-point bending strength and fracture toughness reaches as high as 915MPa and 23
MPa·m1/2, respectively. It is found that the in-situ reaction occurs at 1100°C with the addition of niobium
at the interface between the TiAl matrix and original reinforcement TiC. Further XRD results indicate
that the difference in the reinforcement phase from TiC to Ti2AlC is one of the most important origins to
the variation in mechanical properties.
Complex Permittivity of 3D Textile SiC/C/SiC Composites Fabricated by Chemical Vapor Infiltration at X-Band Frequency
Authors: Zhao Dong Lin , Yin Hong Feng , Xu Yong Dong , Luo Fa , Zhou Wan Cheng
Published: March 2009

Three-dimensional textile SiC fiber reinforced SiC composites with pyrolytic carbon
interfacial layer (3D-SiC/C/SiC) were fabricated by chemical vapor infiltration. The microstructure and
complex permittivity of the 3D textile SiC/C/SiC composites were investigated. The flexural strength of
the 3D textile SiC/C/SiC composites was 860 MPa at room temperature. The real part (ε′) and imaginary
part (ε″) of the complex permittivity of the 3D-SiC/C/SiC composites are 9.11~10.03 and 4.11~4.49,
respectively at the X-band frequency. The 3D-SiC/C/SiC composites would be a good candidate for
structural microwave absorbing material.
Gelcasting of Alumina-Spinel Refractories
Authors: Liu Kai Qi , Pan Wei , Fan Zheng Kun , Liu Yong Feng , Wang Bing Jun
Published: March 2009

The preparation process of alumina-spinel slurries by using micro-sized alumina-spinel
mixtures as raw materials was investigated. The slurries with solids content of 62 vol% and viscosity of 0.3
Pa·s were prepared by adding self-made dispersant ANSP which was a mixture of AN-2000 and STP in
mass ratio of 4 to 1. The alumina-spinel refractory was fabricated from the slurries by gelcasting process.
The dry parts containing micro-sized alumina-spinel powders with 3.57wt% gel have the highest bending
strength of 29.8 MPa and 17.6 MPa with 15:1 AM-MBAM and 4:1 MAM-MBAM respectively. The
bending strength enhanced with the increase of reaction temperature. For example, to the 15 wt% 15:1
AM-MBAM gel premix, the bending strength of the parts gelled at 25°C and 55°C were 27.3 MPa and
32.4 MPa respectively. The bending strength also increased with the rising of the amount of monomer.
Bond Strengths of Alumina-Glass and Zirconia-Glass Composites to Opaque-Dentine Porcelain
Authors: Zhang Shao Feng , Gao Jing , Tian Jie Mo , Jia Jun , Li Jiang
Published: March 2009

This study was conducted to evaluate shear bond strength between self-made alumina glass
composites (AGC), zirconia glass composites (ZGC) and Vita alpha opaque-dentine porcelain, and also
evaluate the effects of different surface treating methods on the bond strength. The AGC and ZGC
specimens were treated differently and then bonded with Vita alpha opaque-dentine porcelain. The bond
strength was measured by shear test and the surface treating methods included no-treatment, sandblasting
and etching. The results showed that the values of bond strength for AGC groups were 30.1, 41.1 and 41.9
MPa respectively, and the bond strength of both sandblasting group and etching group were significantly
higher than that of the untreated group; the bond strength of ZGC groups were 60.2, 63.6 and 35.5MPa
respectively, and the value of sandblasting group was significantly higher while etching group was lower
than that of untreated group. These results indicated that Vita alpha opaque-dentine porcelain can be well
sintered to self-made AGC and ZGC. Sandblasting can greatly improve the bond strength for both AGC
and ZGC, while the etching treating method had different effect on their bond strengths.
Residual Stress and Stability of Thermal Barrier Coatings during Cyclic Thermal Loading
Authors: Xu Ying Qiang , Gao Xi Ya , Yuan Yu An , Wang Zhen Long , Zhou Ren , Lv Guo Zhi
Published: March 2009

The residual stress accumulation of thermal barrier coatings (TBC) during thermal cycling has
been simulated by thermal elastic-plastic finite element method. Stability process of thermal barrier
coatings during thermal cycling is studied by Melan's static shakedown theorem considering thermal
gradients and thermal expansion misfit. The influences of the interfacial morphology of top coat / bond
coat (TC/BC) on residual stress and stability process are analyzed. Thus, the residual stress and stability
process are affected remarkably by interfacial topography between TC and BC. Accidented interface
cause the sudden change of the interfacial residual stress which is harmful to interface bonding intensity
and stabilization. It is useful information for studying of the life and final spallation of TBC system.
Preparation of Cu Coated ZrW2O8 Composite Powders via Heterogeneous Precipitation Process
Authors: Yan Xue , Qiu Jie , Wang Chun Sheng , Zhang Cheng Hua , Cheng Xiao Nong
Published: March 2009

ZrW2O8 powder was prepared by the solid-state method. A heterogeneous precipitation process
was developed to fabricate Cu coated ZrW2O8 composite powders based on a cementation process under
100oC. SEM and XRD were applied to assess the coating quality as well as the phase composition. The
result shows that the mean size of ZrW2O8 powders is less than 2 microns. The nanometer compounds are
easier formed on the surface of the spheric agglomerated ZrW2O8 powders. The Cu coated ZrW2O8
composite powders can be obtained with flowing hydrogen at 300oC.
Electrical Conductivity in Alkali Iron Phosphate Glasses
Authors: Li Tong Wei , Tang Zheng Xin , Ju Wei Wei , Gong Xiao Yang
Published: March 2009

The electrical properties of 10M2O-36Fe2O3-54P2O5 (M=Li, Na and K) glasses were studied in
the temperature range from 323 to 573 K. Non-linear Arrhenius behavior was observed for all the samples
examined. It was shown that in both high- and low-temperature ranges, the replacement of Li, Na and K
would result in decreases in both the dc conductivity and the activation energy. Analysis of the relationship
of the parameters included in the Arrhenius equation, activation energy and the pre- exponential
factor for each sample, preliminary explanations for these experimental phenomena have been presented.
Combustion Synthesis of Alumina-Based Multiphase Foam Ceramic
Authors: Li Jun Shou , Li Liang , Wang Jian Jiang , Xu Bing She , Yin Yu Jun
Published: March 2009

Al2O3-TiO-TiO2 multiphase foam ceramic was prepared with Al powders and TiO2 powders by
combustion synthesis, Direct observation and metallographic microscope indicated that the pore diameter
is 100~6000μm, and Archimedean method showed that the porosity is 35~50%. The influencing factors
of the pore diameter and porosity and, the effects of adding SiO2 on compression strength of the Al2O3-
TiO-TiO2 multiphase foam ceramic were discussed. It was shown that the addition of proper high temperature
foaming agent can increase porosity and adding SiO2 can decrease porosity. The Al2O3-TiO-TiO2
multiphase foam ceramic has good mechanical properties and high-temperature resistance.
Preparation and Characterization of Coated ZnO Nanoparticles
Authors: Xue Tao , Nie Deng Pan , Zeng Shu , Zhang Yu , Pan Lu
Published: March 2009

SiO2 coated and SiO2/Al2O3 coated nano-ZnO were synthesized by chemical liquid deposition
method. The surface properties and dispersion stability of the coated and uncoated ZnO nanoparticles
were characterized. The results showed that a SiO2 or SiO2/Al2O3 amorphous layer was coated on the ZnO
nanoparticles. The adsorbed hydroxyl content of ZnO was found to increase accompanied by the decrease
of UV-shielding ability by surface modification; moreover, the isoelectric point of ZnO slurry was
changed, and the stability of nano-ZnO in water was also improved effectively.
Modeling on Falling Velocity of Sodiumtetraborate Aqueous Solution Drops before the Gelation of PVA-TiO2 Suspensions by the Runge-Kutta Method in Matlab 6.5
Authors: Yu Cheng Long , Wang Xiu Feng , Zhou Jun Xin , Jiang Hong Tao , Wang Yan
Published: March 2009

Numerical modeling on falling of sodiumtetraborate aqueous solution drops as the initiator
before the gelation of PVA-TiO2 suspensions was conducted. Effect of time and elevation angle of the
PVA-TiO2 suspensions on the falling velocity of the sodiumtetraborate aqueous solution drops was
analyzed. An ordinary differential equation was given. Integration of the ordinary differential equation
was fulfilled using the fourth-order Runge-Kutta method in Matlab 6.5. From the model, a two-order
nonlinear effect of time on the velocity of the drops during falling is determined and the quadratic term
-3.408t2 serves as the time dependent air resistance. The component of the falling velocity along the
suspensions increases with the increasing of the elevation angle. However, for the component vertical to
the suspensions, with elevation angle increasing, it decreases.
An Original Process of Nanoporous Materials via Templating Nickel Phosphate Colloidal Particles
Authors: Han Ruo Bing , Wan Chun Lei , Wu Hui , Pan Wei
Published: March 2009

A novel templating method for preparing nanoporous materials has been developed. Spherical
nickel phosphate particles synthesized through a homogeneous precipitation method were used as
templates after annealing to fabricate porous metals. Effort of annealing temperature on the morphology
of the spherical particles and the structure of outcome materials were studied. Hierarchical nanoporous
metal with a high surface area was obtained using a template annealed at 200 oC.
Microstructure and Mechanical Properties of High Density PCBN Aggregates
Authors: Ren X.J. , Wang Ming Zhi
Published: March 2009

Polycrystalline cubic boron nitride (PCBN) is formed by sintering cubic boron nitride particles
(cBN) at high temperature and high pressure. In this process, a network of cBN particles is formed by
intergrowth and bridging between the particle phases. The response of the aggregate to applied stresses in
process such as hard machining, will therefore principally involve the deformation of this skeletal
structure. In this work, the microstructure and hot hardness and adhesion properties of three high-density
PCBN aggregates were comparatively studied. The results were correlated to their cutting performance
and wear modes in machining a carbide-based hardfacing material.
Preparation of Mg and Ti Co-Doped NiO-Based Ceramic and its High Dielectric Properties
Authors: Cheng Bo , Lin Yuan Hua , Cai Jing Nan , Nan Ce Wen
Published: March 2009

We present Mg and Ti co-doped NiO-based polycrystalline ceramic with high-permittivity
dielectric properties. Analysis of the ceramic’s microstructure and composition proves that obvious grain
boundaries NiTiO3 are formed. The measurements of frequency and temperature dependence of
impedance and dielectric permittivity indicate that the grain and grain boundaries have remarkable
influence on the dielectric properties due to the various activation energies.
Effects of Processing on Microstructure and Dielectric Properties of Ultrafine- Grained Barium Titanate Based Ceramics for BME-MLCC Applications
Authors: Wang Tian , Wang Xiao Hui , Yao Guo Feng , Zhang Yi Chi , Liao Xun Xun , Yang Gang , Song Tae Ho , Li Long Tu
Published: March 2009

Ultrafine-grained ceramics based on nano-scale barium titanate for BME-MLCC applications
have been prepared. Relationships of milling time, microstructures and dielectric properties have been
investigated. With processing selected carefully, the present ceramics show ultrafine grain size (180nm)
and homogeneous microstructures, well with high dielectric constant (ε25=2550), low dielectric loss
(<0.02), high resistivity, high breakdown field and X7R temperature specifications, which would be
promising materials for the next generation BME-MLCC applications.
Preparation of ZnO Nanopowder by Chemical Liquid-Phase Method with Polyethylene Glycol Additives
Authors: Yi Zhong Zhou , Liu Wei , Zhang Guo Wei , Li Ying , Xie Zhi Peng
Published: March 2009

One-dimensional ZnO nanopowder was prepared by chemistry liquid-phase method with polyethylene glycol (PEG) as additive in [Zn(OH)4]2- premonitory solution. TEM results showed that the nanopowder with the diameter of 30~50nm has the structure such as the good crystal state and well-defined crystallographic surfaces. The UV–Vis absorption revealed that the ZnO nanopowder have strong absorption in the UV region. The function of polyethylene glycol and the effects of solvent conditions were discussed.
P-Type Transparent Conductivity of Cu1-xAlS2 (x = 0 ~ 0.08)
Authors: Liu Min Ling , Huang Fu Qiang , Chen Li Dong
Published: March 2009

A series of Cu1-xAlS2 (x = 0 ~ 0.08) bulk samples were synthesized by spark plasma sintering. The electrical and optical properties were investigated. P-type conductions for all samples were confirmed by both positive Seebeck coefficient and Hall coefficient. Bulk undoped CuAlS2 had a high conductivity of about 0.9 S/cm with a large band gap of 3.4 eV at room temperature. For vacancy-doped in Cu site, the carrier concentration was highly enhanced, reaching 1.7 × 1019 cm-3 for 8 mol% doped sample, and without decreasing the bang gap. The introduction of vacancies destroys the continuity of Cu-S network, which decreases the Hall mobility.
Preparation and Characterization of Pr-CeO2 Nano-Powders by Co-Precipitation-Hydrothermal Method
Authors: Zhu Zhen Feng , Li Jing Ping , Yang Jun
Published: March 2009

Pr-CeO2 nano-size powders with the average crystallites size of 12 nm and particle size of 18
nm were prepared by a co-precipitation-hydrothermal method using Ce(NO3)3·6H2O, Pr6O11 as raw
materials and ammonia as the precipitation agent. The influence of hydrothermal treatment time,
hydrothermal treatment temperature on the average crystallites size, color of powders and the solubility of
praseodymium were investigated. The synthesized powders were characterized by X-ray diffraction,
transmission electron microscopy and color measurements. Results showed that after calcining at 800°C
for 4 hours, the color of the as-prepared powder changes from light red to red brown, the solubility of
praseodymium and the crystallites size of the Pr-CeO2 powder both increase.
Preparation of Microcrystalline CBN Abrasive
Authors: Zhang Ai Ju , Li Zhi Hong , Li Zi Cheng , Zhu Yu Mei
Published: March 2009

In this paper microcrystalline CBN abrasives are prepared with CBN powders and vitrified bond additives by pressureless sintering method. Mechanical properties of the products are measured by using single particle compressive strength tester and three-point bending strength tester. The effects of vitrified bond additives, the CBN powders particle size and the sintering temperature on the performance of microcrystalline CBN abrasives are investigated. The microstructure characteristics of microcrystalline CBN abrasives are examined. The results showed that the performance and microstructure of microcrystalline CBN abrasives are significantly influenced by particle size of CBN powder and the addition amount of vitrified bond.
Theoretical and Experimental Research on Tapping of GH4169 and TC4 with Modified-Tooth Taps
Authors: Tang Yan Li , Han Rong Di , Ju Jia Bin
Published: March 2009

Based on the theoretical principle of tapping formation and simulation with
modified-tooth tap, the relationship among the different geometric parameters of the tap was further
analyzed. A series of modified-tooth taps and standard ones with a cutting cone angle of 7°30´and a
outer diameter of M6, which were made from high-speed steel W9, were taken to do the
comparative tapping test on nickel-based high-temperature alloy GH4169, titanium alloy TC4 and
45 steel. The test results indicated that the leading cause of difficult tapping in GH4169 and TC4
was the largeness of their friction torques which were about 35 % and 62 % of tapping torque
respectively, where the frictional wear was a fundamental reason for tough tapping GH4169 and the
spring back of machined surface for TC4.The obvious decreases of friction torque with the
modified-tooth tap approximately 70% and 50% respectively for GH4169 and TC4 were attributed
to its unique tapping formation principle of generating broaching but no remarkable effects on 45
steel in comparison with standard tap.
Research on Chemical Mechanical Polishing for Silicon Nitride Ceramics
Authors: Zhu Cong Rong , Yuan Ju Long , Xu Qin , Lv Bing Hai
Published: March 2009

Silicon nitride ceramics materials have excellent properties such as small density, high
rigidity, high Young's modulus, high wearability, good thermal stability and chemical stability,
which make it become one of the most appropriate materials for rollers of high precision bearing.
Chemical Mechanical Polishing (CMP) technology is employed to have an ultra-precision
machining process for silicon nitride ceramics materials workpiece and the effects of workpiece
surface roughness in different abrasive are discussed in this research. The XRD and SEM
technology are used to take phase analysis and surface profile detection for the finishing workpiece
polished with CeO2 abrasive. The chemical reaction mechanism and the material remove
mechanism of silicon nitride ceramics materials in CMP process with CeO2 abrasive are both
analysed and discussed in this paper. The research result shows that an extremely smooth surface of
silicon nitride ceramics materials workpiece with roughness 5nm Ra is obtained after CMP process
with polyurethane polishing pad and CeO2 abrasive.