Bone Formation Process of β-TCP Ceramics with Tetracycline Tracing

To study the new bone formation in the bone defect area after implantation, the tetracycline tracing method was used. The results show that new bone formed in 1 month, and the formation rate of new bone was very high (8. 164 μm/day), considerably faster than that of control groups (3.219 μm/day). The new bone grew up quickly and β_TCP particles were surrounded by double fluorescence bands which became more obvious. The new bone formation rate was maximal at 2 months, and then gradually reduced. The rate was steady at 4 months, and then reduced to resembling as the normal physiologic metabolism of bone, which indicated the implanted materials were completely replaced by bone. Calcium phosphate materials had the ability of osteoconduction.     

The Properties of YSZ Electrolyte Sintering at 1300 ℃

The properties of yttria stabilized zirconia（YSZ） related to the sintering process were discussed.YSZ nano-powders about 40-100 nm as raw material,the sub-micrometer grain sizes such as 0.4-3 μm in YSZ were gotten by sintering process at 1300 ℃,which was performed at 1000 ℃ for 2 h,then raised the temperature at the rate of 50 ℃ / h to 1400 ℃,then decreased directly to 1300 ℃ in 30 minutes,finally at 1300 ℃ for 5-20 hours.The ratio of bigger grain size becomes larger as the holding time increasing at 1300 ℃.The grains less than 1 μm are about 50%,eg,43.2%,52.2% and 51.1% related to 1300 ℃ holding 5 hours,8 hours and 10 hours,respectively.As YSZ grain size became small,the electrical conductivities did not decrease,even increased,about 0.20 s/cm at 1000 ℃.The reduced sintering temperature and time were benefited to co-fire with the electrodes in electrode-supported SOFCs.     

Optimization of the process of gelatin-ceftiofur sodium microspheres

Gelatin microsphere(GMS) was prepared through W/O emulsion chemical-crossline method.The best formula was selected by examining its appearance,size,drug carrier and drug dissolution rate.The experimental results showed that the optimized gelatin microspheres were spherical ball with smooth surface and had well dispersion.The average size of blank gelatin microspheres was 15.84 μm,while the loaded microspheres'average diameter were 33.10 μm.It was also shown that drug loading of microspheres increased with increasing loading capacity,but drug encapsulation efficiency had a trend of climbing up and then decline.The encapsulation efficiency reached the maximum when the dosage ratio was 2:1.And the results show ceftiofur sodium microspheres have sustained release in the PBS buffer of pH7.4.     

Preparation of ZrB2 Ceramics by Self-propagating High-temperature Synthesis and Hot Pressing Sintering

ZrB2 ceramics were prepared by self-propagating high-temperature synthesis（SHS） and were sintered by hot pressing（HP）.The effects of the granularities and doses of raw materials in Zr-B2O3-Mgon SHS process and product were investigated.XRD and combustion temperature curves prove that the ideal SHS reactants of Zr-B2O3-Mg are 50μm Zr powder,75μm B2O3 powder and 400μm Mg powder with 45% excessive.The particle sizes of SHS product,acid-leached product,sintered product are 2-5μm,0.5-2μm,2-10μm respectively.Chemical analysis indicates that the acid-leached product consists of ZrB2（94.59%）,ZrO2（3.87%）,and H3BO3（1.54%）,The sintered product has a relative density of 95.4%.     

Preparation of conducting poly N-methylaniline microsphere and its antibacterial performance to sulfate reducing bacteria

Microspheres of conducting polymers poly N-methylaniline （PNMA） were successfully synthesized through oxidation of N-methylaniline without any template. The average diameter of the microspheres with a smooth surface was about 0.40 μm when 0.2 M N-methylanUine was oxidized with 0.2 M ammonium persulfate in 0.2 M of HClO4 solution. The size of microspheres can be controlled by changing reaction time and temperature. The acid concentration was critical for the formation of microspheres with smooth surfaces. The excellent antibacterial performance of PNMA in novolac epoxy coating to sulfate reducing bacteria was demonstrated. Moreover, in API media, PNMA inhibited growth of SRB and then reduced the corrosion rate of carbon steel remarkably.     

High sp3 content hydrogen-free amorphous diamond: an excellent electron field emission material

Details are given of a study of the characteristics of field-induced electron emission from hydrogen-free high sp³ content (>90%) amorphous diamond (a-D) film deposited on heavily doped (ρ<0.01ω·cm) n-type monocrystalline Si (111) substrate. It is demonstrated that a-D film has excellent electron field emission properties. The emission current can reach 0.9 μA at applied field as low as 1 V/μm, and the emission current density can be about several mA/cm² under 20 V/μm. The emission current is stable when the beginning current is at 50 μA within 72 h. Uniform fluorescence display of electron emission from the whole face of the a-D film under the electric field of 10–12 V/μm is also observed. The contribution of excellent electron emission property results from the smooth, uniform, amorphous surface and high sp³ content of the a-D film. Project supported by the National High-Tech Program of China.     

Osteogenesis Capacity of a Novel BMP／a-TCP Bioactive Composite Bone Cement

To improve the osteogenesis ability of α-trkalcium phosphate (a-TCP ) bone cement, a novel BMP/ a- TCP composite bone cement was prepared. By measuring the setting time and compressive strength, the hydration characteristic of bone cemtwnt icts eralnated. Animal experiments including histological observation, radiographic investigation as well as digital image analyses reveal the difference of osteogenesis ability among BMP, a TCP bone cetnent and BMPI a-TCP composite bone cement, Results show that a-TCP bone cement possesses excellent hydration and setting properties as well as high mechanical property, Comparison experiments show that BMPI a-TCP composite bonc cement has a stronger osteogenesis obility. The gross observation of the implant site does not exhibit any inflammation or necrosis. Histohwcal analyses reveal that the material has good osteointegration with host bone, and new bone formntion is detected within the materials, which are degrading. Strong osteogenesis ability of the composite is due to not only the excellent osteoconductive potential but also the osteoinductive potential contributed by attire BMP releasing and the material degradation . Large skull defect could be well-healed ty filling BMPl a-TCP composite bone cement. This novel material proves itself to be an absorbable and bioaetive bonecement with an osteogenesi ability.     

Research on the preparation of amorphous diamond nanorod arrays and their excellent field emitting properties

During recent years, with the rapid development of IT and micro-electrics, the ultra- thin, ultra-large display screen with low power consumption, has attracted more and more attention. As the core of devices, cathode materials are made much more demands in the vacuum microelectronic technology. So the materials with low power consumption, outstanding field emission properties and extreme stability are very important. To resolve the problem, many researchers have been making efforts. Diamonds…     

Design of small-area multi-bit antifuse-type 1 kbit OTP memory

A multi-bit antifuse-type one-time programmable (OTP) memory is designed, which has a smaller area and a shorter programming time compared with the conventional single-bit antifuse-type OTP memory. While the conventional antifuse-type OTP memory can store a bit per cell, a proposed OTP memory can store two consecutive bits per cell through a data compression technique. The 1 kbit OTP memory designed with Magnachip 0.18 μm CMOS (complementary metal-oxide semiconductor) process is 34% smaller than the conventional single-bit antifuse-type OTP memory since the sizes of cell array and row decoder are reduced. And the programming time of the proposed OTP memory is nearly 50% smaller than that of the conventional counterpart since two consecutive bytes can be compressed and programmed into eight OTP cells at once. The layout area is 214 μm × 327 μm, and the read current is simulated to be 30.4 μA. Foundation item: Project supported by the 2nd Stage of Brain Korea; Project supported by the Korea Research Foundation     

Preparation and characterization of Bi4Ti3O12 platelets by a novel low-temperature molten salt system

Bismuth titanate (Bi₄Ti₃O₁₂) platelets were prepared by molten salt method in a new salt system of CaC_l2-NaCl at 650–750 °C, using bismuth nitrate pentahydrate (Bi(NO₃)₃―H₂O) and titanium butoxide (Ti (OC₄H₉)₄) as raw materials. The synthesis temperature of Bi₄Ti₃O₁₂ platelets was decreased to 650 °C from 900–1100 °C. The phase compositions and crystalline morphology of Bi₄Ti₃O₁₂ platelets were investigated by XRD and SEM. The experimental results indicate that Bi₄Ti₃O₁₂ platelets containing tetragonal and orthorhombic phase with the size of 1–3 μm can be synthesized at 650 °C for 2 h, and the orthorhombic phase becomes the dominant phase at 750 °C for 5 h. The size and proportion of Bi₄Ti₃O₁₂ platelets increase with the increment of the calcining temperature and holding time. The proportion of platelets increases to about ninety percent, and the platelets grow up to about 3–10 μm at 750 °C for 5 h from 1–2 μm at 650 °C for 2 h. This technical route provides a new low-temperature molten salt system for preparing platelets by molten salt methods.