Preparation and crystallization control of nanoparticle hydroxyapatlte

Nanoparticle hydroxyapatite was prepared by a wet chemical precipitation method. The effects of different synthesis conditions, i.e. contents of reagents (0.2, 0.5 and 0.8 mol/L), reaction temperatures (20, 37, 55 and 75℃) and reaction time (0-24 h), were studied based on crystallization process analysis and the effects of washing methods (with water or alcohol) were also studied. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED) and inductively coupled plasma spectroscopy (ICP) were used to characterize the powders. Chemical analysis shows that the purity of the precipitated hydroxyapatite largely depends on reaction time. X-ray diffraction and TEM micrographs results show that reaction temperature is a key factor affecting crystallinity, morphology and particle size. Degree of supersaturation and stirring also affects the crystallization. Particles are in a shape of short rod and have a size of 20-40 nm in lengt     

One-dimensional nano-structure of Cu-Zn-Al alloy

Cu-Zn-Al alloy of one dimensional nano-structure was prepared and the structure of obtained nano-material was characterized by transmission electron microscope (TEM). It was shown that there are non-linear oscillations on the surface of Cu-Zn-Al alloy and the consanguineous connection exists between non-linear oscillation and the growth process of one dimensional nano-structure. The diameter of one dimensional nano-structure is about 40 nm, and the ratio of length to diameter is over 40. Finally, the growth mechanism of one dimensional nano-structure was also studied.     

Tridimensional Treatment Planning and Rapid Prototyping for Maxillofacial Prosthesis

1　IntroductionThesuccessofmostmaxillofacialsurgerydependsoncarefulanalysisandplanningbasedonavarietyofdiag nosticinformationsuchasphotographs ,radiographsandarticulateddentalmodels .Intheconventionalcephalo metricX raytreatmentplanning ,thesurgicalprocedureisvisualizedinthemid sagittalplane .Ifthepatientshaveasymmetricdeformities ,projectionofthefacialanatomyonthemid sagittalplanedoesnotprovideadequateevalu ationandplanning ,whichmakesthetherapeuticdecisiondifficult .Thisisthereasonwhymany 3…     

Quality Improvement of Granular Wastes-The Effective Way to Recycle Secondary Raw Building Materials

1　IntroductionTherearefourmaintypesofgranularwastematerialslistedinTable 1.Constructionanddemolitionwaste(CDW )arefromtheconstruction ,remodelling ,repairinganddemolishingofbuildingsandotherstructures .Ashesaretheresiduesfromburningofwood ,coal ,andother…     

论破产中债权人利益不当减损的法律缺失与对策

破产本是一种公平的偿债方法,但破产实践中屡屡发生债权人利益受损的不公平现象,其直接根源在于我国破产法的粗陋与不成熟,比如破产中缺乏专门的监督组织、债权人会议难以发挥作用、个别破产财产、破产债权的界定不合理,等等,我国在新破产法的制订过程中应积极寻求对策,保护债权人的合法权益。     

高校图书馆实施文化素质教育的思考

高校图书馆实施文化素质教育,是时代的要求和必然趋势。"课堂型教育--环境熏陶--宣传引导"三位一体是高校图书馆实施文化素质教育的实践模式。为了保障该模式的顺利实施,必须树立使命感和新的服务育人理念,提高馆员的文化素质,建立良好的运行机制。     

Correlations between the Optical Properties and the Microstructure of TiO_2 Thin Films Prepared by Reactive Electron-beam Evaporation

1　IntroductionInrecentyears ,theoreticalandexperimentalinvesti gationsonthetitaniumoxidefilmsareconductedonac countoftheirremarkableproperties .Titaniumdioxidefilmshaveattractedconsiderableattentiontoapplytomi croelectronicdevices ,opticalthin filmdevice…     

Microstructure and Thermal Properties Analysis of (1-x)As_ 2S_3-xCdBr_2 Glass System

1　IntroductionChalcohalideglassesareformedbyaddinghalideel ementsorhalidesalts[1] tothechalcogenideglasses .Theadditionofhalogenssuchaschlorine ,bromineandiodineresultsinadestructionofthethree dimensionalnetworkofchalcogenideglasses .Inrecentyears ,chalc…     

Properties of Nano SiO_2 Modified PVF Adhesive

1　IntroductionPVFadhesiveispolyvinylformalone .Ithasaseriesofadvantages ,suchascheapprice ,easyproduction ,convenientuse ,nopoisonandnoenvironmentalpolluc tion ,andisusedwidelyinthefieldofwood ,paper ,tex tile ,leatherandbuildingmaterial,etc .Butitispoor…     

下一代网络端到端QoS体系的研究

随着下一代网络的发展,如何保障下一代网络端到端QoS是一个重要的研究课题.分析了下一代网络的特点,提出了下一代网络端到端QoS的分层体系结构,指出了保障下一代网络QoS时要研究的一些重要问题.