Preparation and Characterization Analysis of Hydroxyapatite/ Gelatin Composite

The hydroxyapatite （ HAp ）/gelatin composite was prepared by self-assembly method. X-ray diffraction confirmed that the inorganic phase in the composite was HAp. The Fourier transform infra-red spectrum （FT-IR） indicated the presence of amide and hydroxyl groups in the composite. The organic-inorganic ratio of the composite is similar to that of the human bone, which was determined by differential thermal analysis （ DTA ） and thermogravimetric analysis （ TGA ）. Transmission Electron Microscopy （TEM） showed that the composite is composed by spindly grains and the rmdtilayer nanostructure can also be seen. Gelatin in the composite assembled orderly and orderly and directionally ; and the HAp crystals grew along the gelatin molecule at nearly the same direction. A model was established to explain the process of the interaction between gelatin and HAp.

XRD,TEM and HREM Study on B-site Ordered Structure of PMW-PZT Doped with ZnO Ceramics

The B-site ordered structure of Pb(Mg1/2W1/2)O3-Pb(Ti1-xZrx)O3 doped with ZnO ce-ramics is investigated by using a X-ray diffractometer,transmission electron microscopy andhigh resolution transmission electron microscopy.It is shown that（111）-type superlatticeexists in both of the XRD pattern and selected-area electron diffraction（SAED）images.Three kinds of（111）-type superlattice diffraction have been observed in[011]zone SAEDdark-field image by TEM.Two kinds of ordered structure,the large ordered regions（≥100nm）and the nanoscale ordered domains（=2-50nm）,have been found by HREM.It issuggested that the dual peaks in the ε-T curve are caused by the complex dielectric proper-ties of the different ordered degree grains in the PMW-PZT doped with ZnO ceramics.

Simulation of calcium oxalate stone in vitro

Crystallization of calcium oxalate is studied mainly in the diluted healthy urine using scanning electron microscopy (SEM), and is compared with the crystallization in the diluted pathological urine. It suggests that the average sizes of calcium oxalate crystals are not in direct proportion to the concentrations of Ca2+ and Ox2- ions. Only in the concentration range of 0.60-0.90 mmol/L can larger size of CaOx crystals appear. When the concentrations of Ca2+ and Ox2- ions are 1.20, 0.80, 0.60, 0.30 and 0.15 mmol/L in the healthy urine, the average sizes of calcium oxalate crystallites are 9.5 X 6.5, 20.0 X 13.5 and 15.0 jj,m X 10.0 jj,m, respectively, for the former three samples after 6 d crystallization. No crystal appears even after 30 d crystallization for the samples of concentrations of 0.30 and 0.15 mmol/L due to their low supersaturations. The results theoretically explain why the probability of stone forming is clinically not in direct proportion to the concentrations of Ca2+ and Ox2- ions. Laser scattering technology also confirms this point. The reason why healthy human has no risk of urinary stone but stone-formers have is that there are more urinary macromolecules in healthy human urines than that in stone-forming urines. These macromolecules may control the transformation in CaOx crystal structure from monohydrate cal-cium oxalate (COM) to dihydrate calcium oxalate (COD). COD has a weaker affinity for renal tubule cell membranes than COM. No remarkable effect of the crystallization time is observed on the crystal morphology of CaOx. All the crystals are obtuse hexagon. However, the sizes and the number of CaOx crystals can be affected by the crystallization time. In the early stage of crystalli-zation (1-6 d), the sizes of CaOx crystals increase and the number of crystal particles changes little as increasing the crystallization time due to growth control. In the middle and late stages (6-30 d), the number of crystals increases markedly while the growth rate changes little due to the nucleation control.

Solvothermal preparation and thermoelectric properties of quasi-binary Sn(Pb)Te-Bi_(2)Te_(3) compounds

Bulk samples of quasi-binary compounds in the Sn(Pb)Te-Bi2Te3 system were prepared by solvothermal method followed by a sintering procedure of compacted pellets. The formation mechanism of the precursor powders, microstructure and thermoelectric properties of the final bulk samples were studied.

Growth Ledges at Nanometer Scale of Bainites in Cu-Zn-Al Alloys

The bainitic transformation mechanism is one of the controversial issues in solid phase transformations on which sharp arguments have lasted for a long time. A lot of research work on this mechanism has been done by both the shear and diffusion schools. Results from these two schools have many differences and the viewpoints on them are different essentially as

Preparation of 3-D porous fibroin scaffolds by freeze drying with treatment of methanol solutions

In this study, silk scaffolds with appropriate porous structures were prepared by adjusting solution concentrations and providing treatment with methanol solutions in the way of freeze drying. The effects of the preparation conditions on the microstructures and properties of the scaffolds were discussed. Fibroin solutions with different concentrations of 4, 6, 8, 10 wt% were used respectively to prepare the scaffolds. The effects of the addition of 20 vol% methanol before or after freeze drying to the 4 wt% fibroin solution were investigated. As demonstrated by Scanning Electron Microscope (SEM), the fib-roin scaffolds prepared without methanol had porous microstructures composed of thin sheets, and the sizes of the pores decreased with the increase of the fibroin solution concentrations, while the scaffolds prepared in the presence of methanol showed porous microstructures formed by fine-particle aggregates. The porosities and mechanical properties of the prepared fibroin scaffolds under different conditions were tested. The crystalline structures and conformations of the fibroin scaffolds were detected by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD).

Preparation and self-scaling behavior of a 3-layer MCrAlX composite coating

A 3-layer CH220/MCrAlX/Al composite protective coating has been designed and prepared by means of two PVD techniques, the multi-arc ion plating and magnetron sputtering so as to improve the surface stability （i.e. the oxidation and corrosion resistance properties）, internal oxidation degradation of MCrAlX coating, and the interfacial stability of MCrAlX/substrate. Ti-N itself is also a composite film, consisting of δ-TiN, ε-Ti2N and α-Ti. The average composition of magnetron-sputtered MCrAlX is Co-32Cr-2.6Al-

Flexible supercapacitors

Flexible supercapacitors show a great potential for applications in wearable, miniaturized, portable, large- scale transparent and flexible consumer electronics due to their significant, inherent advantages, such as being flexible, lightweight, low cost and environmentally friendly in comparison with the current energy storage devices. In this report, recent progress on flexible supercapacitors, flexible electrodes and electrolytes is reviewed. In addition, the future challenges and opportunities are discussed.