Materials such as Koch AH—70, basalt aggregate, limestone powder and graphite particles were used to prepare conductive asphalt concrete, which is a new type of multifunctional concrete. The mix proportion by weight was shown as follows. Fine aggregates (2.36–4.75 mm): fine aggregates (<2.36mm): lime-stone powder: asphalt=120∶240∶14∶30. The content of added graphite particles ranged from 0% to 20% (by the weight of asphalt concrete). A conductive asphalt concrete with a resistivity around 10–10³Ω·m was obtained. Special attention was paid to the effects of graphite content, graphite physical-chemical properties, asphalt content and temperature on the resistivity. Furthermore, an attempt was made to develop an electrically conductive model for asphalt concrete.

An experimental program was undertaken to study the individual and admixed effects of lime and fly ash on the geotechnical characteristics of expansive soil. Lime and fly ash were added to the expansive soil at 4%–6% and 40%–50% by dry weight of soil, respectively. Testing specimens were determined and examined in chemical composition, grain size distribution, consistency limits, compaction, CBR, free swell and swell capacity. The effect of lime and fly ash addition on reducing the swelling potential of an expansive soil is presented. It is revealed that a change of expansive soil texture takes place when lime and fly ash are mixed with expansive soil. Plastic limit increases by mixing lime and liquid limit decreases by mixing fly ash, which decreases plasticity index. As the amount of lime and fly ash is increased, there are an apparent reduction in maximum dry density, free swell and swelling capacity under 50 kPa pressure, and a corresponding increase in the percentage of coarse particles, optimum moisture content and CBR value. Based on the results, it can be concluded that the expansive soil can be successfully stabilized by lime and fly ash.

A new model of repaired concrete which divides the bonding interface into a penetrating layer, a strongly-affected layer and a weakly-affected layer was put forward. The model is mainly based on the observation of the microstructure of interface between fresh and old (3 months to 60 years) concretes by using scanning electron microscopy. Then, the mechanism of the microstructure formed was analyzed. Finally, the relationship between the micro-structure and macro-mechanical performance of the interface was discussed. V 3

By means of “Mortar Bar Method”, the ratio of cement to aggregate was kept as a constant 1∶2,25 the water-cement ratio of the mixture was 0.40, and six prism specimens were prepared for each batch of mixing proportions with dimensions of 10×10×60mm³ at 38±2°C and RH≧95%, the influences of content and particle size of active aggregate, sort and content of alkali component and type of slag on the expansion ratios of alkali-activated slag cement (ASC) mortars due to alkali aggregate reaction (AAR) were studied. According to atomic absorption spectrometry, the amount of free alkali was measured in ASC mortars at 90d. The results show above factors affect AAR remarkably, but no dangerous AAR will occur in ASC system when the amount of active aggregate is below 15% and the mass fraction of alkali is not more than 5% (Na₂O). Alkali participated in reaction as an independent component, and some hydrates containing alkali cations were produced, free alkalis in ASC system can be reduced enormously. Moreover, slag is an effective inhibitor, the possibility of generating dangerous AAR in ASC system is much lower at same conditions than that in ordinary Portland cement system.

This paper discussed the preparing process of hydroxyapatite fibers which were widely used as reinformcement for biomedical materials by homogeneous precipitation method. The needle-like hydroxyapatite crystals were synthesized in an aqueous system. They were transferred from precursors-dicalcium phosphate anhydrate and octacalcium phosphate crystals. The reaction conditions were well controlled in order to obtain crystals in given morphology. The products were characterized by X-ray powder diffractometry (XRD), scanning electron microscopy (SEM) and infrared spectroscopy(IR). They were verified to be hydroxyapatite crystals with needle-like in shape.

Normal spinel LiMn₂O₄ was synthesized by sol-gel method using lithium nitrate, manganese nitrate, citric acid and ethylene glycol as raw materials. LiMn₂O₄ was characterized by XRD, TG-DTA, IR, SEM and AAS. The optimum conditions for the synthesis were explored. Citric acid and ethylene glycol were mixed with molar ratio of 0.25, and the mixture was esterified at 140°C for 4 hours. Then lithium nitrate and manganese nitrate were added with molar ratio of 0.6. In the system, the total molar of cations was equal to that of citric acid. At last, reflux the system at 105°C for 2 hours. Dried gel was fired at 600°C for 8 hours. Particle diameters of raw product were about 100 nm mainly. Further research shows that lithium ion of LiMn₂O₄ is easy to be extracted, and normal spinel λ-MnO₂ can be obtained after lithium ion extraction.

To solve the problems of EDM when using the ordinary fluid and mold manufacturing, this paper provides the orthogonal experiment in the suspended powder fluid, which can optimize the main process parameters. And it also achieves the technology of EDM in the suspended powder fluid primarily.

λ-MnO₂ was prepared by column method from normal spinel LiMn₂O₄ with purity of 99.38%. The influence of LiMn₂O₄ grain size and acidity of leaching solution on the lithium leaching process was studied. The results show that the appropriate range of LiMn₂O₄ grain size was 60–160 meshes and the concentration of leaching solution HCl was 0.1 mol·L⁻¹. The adsorption capacity Q of λ-MnO₂ for lithium increased with the increase of pH and changed markedly at pH 6.0–10.0. It was 3.80mmol/g at pH 12.0 The distribution coefficients K_d of Li⁺ and Na⁺ were 3.406×10⁴ and 2.300 respectively, and the separation coefficient a_Na ^Li was 1.481 ×10⁴ at pH 6.5. As a result, λ-MnO₂ is a high performance ion-sieve material for lithium ion.

Tissue engineering has confronted many difficulties mainly as follows: 1) How to modulate the adherence, proliferation, and oriented differentiation of seed cells, especially that of stemcells. 2) Massive preparation and sustained controllable delivery of tissue inducing factors or plasmid DNA, such as growth factors, angiogenesis stimulators, and so on. 3) Development of “intelligent biomimetic materials” as extracellular matrix with a good superficial and structural compatibility as well as biological activity to stimulate predictable, controllable and desirable responses under defined conditions. Molecular biology is currently one of the most exciting fields of research across life sciences, and the advances in it also bring a bright future for tissue engineering to overcome these difficulties. In recent years, tissue engineering benefits a lot from molecular biology. Only a comprehensive understanding of the involved ingredients of tissue engineering (cells tissue inducing factors, genes, biomaterials) and the subtle relationships between them at molecular level can lead to a successful manipulation of reparative processes and a better biological substitute. Molecular tissue engineering, the offspring of the tissue engineering and molecular biology, has gained an increasing importance in recent years. It offers the promise of not simply replacing tissue, but improving the restoration. The studies presented in this article put forward this new concept for the first time and provide an insight into the basic principles, status and challenges of this emerging technology.

To develop a new generation of absorbable fracture fixation devices with enhanced biocompatibility, the biodegradation mechanism and its influence on the cellular response at the tissue/implant interface of hydroxyapatite/poly-DL-lactide (HA/PDLIA) composites were investigated in vitro and in vivo. HA/PDLIA rods were immersed in phosphate-buffered saline, or implanted in muscle and bony tissue for 52 weeks. Scanning electron microscopic and histological studies were done. The degradation rate was the slowest in vitro, slower in muscle tissue and fast in bone. In vitro, the composites degraded heterogeneously and a hollow structure was formed. In bone, the limited clearing capacity leads to the accumulation of oligomeric debris, which contribute totally to the autocatalytic effect. So, the fastest degradation and intense tissue response were seen. In muscle tissue, oligomeric debris migrated into vicinal fibers over a long distance from the original implant cavity and the tissue reactions were, however, quite moderate. For the same size organic/inorganic composite, the environment where it was placed is the major factor in determining its biodegradation process and cellular reaction. In living tissue, factors such as cells, enzymes and mechanical stress have an obvious influence on the biodegradation and biological process at the tissue/implant interface. The biocompatibility of the HA/PDLIA composites is enhanced with the incorporating of the resorbable HA microparticles.

A type of recycling agent was developed and its use for modifying used asphalt is described. The results show that the viscosity and three main properties of the aged asphalt were remarkably improved. With 5%–7% content of recycling agent, the main properties of recycled asphalt comported with China GB asphalt standard AH—70 and the recycled asphalt concrete could be used as high-grade highway. Furthermore, the recycling mechanism of the aged asphalt is discussed.

Shape Memory Alloy (SMA) optically activated is the key technology of optical SMA activator. According to the shape memory mechanism of SMA, researches are done on the activating response time and light wavelength of activating source etc of SMA optically activated to approach the parameters selection of optical activation. SMA has the optimum efficiency in the range of 13 seconds to 27 seconds when SMA is illuminated continuously by wavelength of 675nm; The power of light wave has a low effect on SMA; The longer the activating wavelength, the quicker the response time of SMA activated. If the proper activating time and activating wavelength are adopted, and the structure deformation of composite material of SMA imbedded may be actively controlled, an ideal effect will be gotten. The research provides an evidence for the design of optical SMA activator and is of great significance to its application. The research on smart structure has a wide application prospect.

The relationship between the electrical resistivity of carbon fiber reinforced concrete (CFRC) containing different carbon fiber contents and temperature was studied. it is found that carbon fiber contents influence greatly on the temperature sensibility of CFRC road material. Only with a certain amount of carbon fiber can CFRC show a sensitive and stable temperature sensibility.

The bonding of steel plate to Al-7 graphite slurry was studied for the first time. The relationship model about preheat temperature of steel plate, solid fraction of Al-7 graphite slurry, rolling speed and interfacial shear strength of bonding plate could be established by artificial neural networks perfectly. This model could be optimized with a genetic algorithm. The optimum bonding parameters are: 516°C for preheat temperature of steel plate, 32.5% for solid fraction of Al-7 graphite slurry and 12 mm/s for rolling speed, and the largest interfacial shear strength of bonding plate is 70.6MPa.

Both titanium and germanium were introduced into silicon dioxide system by sol-gel method to move its region of anomalous dispersion caused by IR resonance absorption towards the wavelength of CO₂ laser. It is indicated by IR absorption spectra that as the content of SiO₂ decreases in this glass system TiO₂ and GeO₂ tends to exist in their own phases. As for the gel glass with a composition of 40 SiO₂·30TiO₂·30GeO₂, when the temperature is below 600°C, germanium atoms exist mainly in Ge−O−Ge bonds. With the temperature increasing from 800°C to 1000°C, titanium atoms in Si−O−Ti bonds abmost transform into Ti−O−Ti bonds. Furthermore, a large number of Si−O−Ti and Si−O−Ge bonds formed when the temperature approaches 800°C, which makes a notable IR absorption band round the wavelength of CO₂ laser. Therefore, sol-gel based SiO₂−TiO₂−GeO₂ gel glass is a candidate material for CO₂ laser hollow waveguide.

α-tricalcium phosphate (α-TCP)/tetracalcium phosphate (TTCP) composite bone cement had good hydration characteristic. In our system, α-TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g·mL⁻¹. The setting time could be adjusted, the maximum compressive strength was 45.36MPa, and the hydration product was hydroxyapatite (HAP). In vitro biological simulated experiments indicate that α-TCP/TTCP bone cement has α certain dissolubility. The hardened product is mainly HAP after soaking in simulated body fluid (SBF) for 10 weeks. The results of in vitro test and animal experiments and SEM analyses show that no local or general toxicity response, no muscle stimulation, no haemolysis, no cruor, no inflammatory reaction and no exclusion response are caused by α-TCP/TTCP cement, which can be contributed to bone tissue spreading and impinging. α-TCP/TTCP cement hydrated and hardened continually in vivo. The materials fused with host bone together with implanting time prolonging. Therefore, it is believed that α-TCP/TTCP composite bone cement has a high biocompatibility and bioactivity, a certain biodegradation and good osteogenesis as well.

The effects of mineral admixtures on fluidity, mechanical and hydrational exothermic behavior were studied. The results show that, double-adding ways, i e, fly ash and slag were added at the same time, not only improves the fluidity of fresh concrete with low W/B and compensates the lower early compressive strength of harden concrete caused by high adding amount of fly ash, but also greatly reduces the highest temperature rise, exothermic rate and total heat liberation of 3 day of binder pastes in HLPC, and postponed the arrival time of the highest temperature rise. HLPC was prepared and applied to project practice successfully.

According to the characteristics of granular soil, the technological requirements of the special-purpose cement for stabilizing granular soil are put forward to meet the demands of implementation of highway base engineering. A kind of slow-setting and slight-expansive cement is developed by the cross experiment method in slag-clinker-gypsum-alkaline system, the final setting time of the cement can be prolonged to 8h, and it has properties of low dry shrinkage, high flexural strength and good crack resistance. The strength of granular soil stabilized by the cement is increased by 20% compared with that stabilized by Chinese 425-Grade slag cement.

BN ceramic is an advanced engineering ceramics with excellent thermal shock resistance, good workability and excellent dielectricity. TiB₂ ceramic has excellent electric conductivity, high melting points, and corrosion resistance to molten metal. Therefore, the composite consisting of BN and TiB₂ ceramics is expected to have a combination of above-mentioned properties, thereby can be used as self- heating crucible. In this paper, hot pressing technology was used to fabricate the high performance BN-TiB₂ composite materials. microstructure and electric conducting mechanism were studied, and the relationship between the microstructure and physical property was discussed. The results show that the microstructure of composites has a great influence on the physical property of composites. The BN-TiB₂ composites with excellent mechanical strength and stable resistivity can be obtained by optimizing the processing parameter and controlling the microstructure of composites.

The method of controlling separating anode and separating power source was used to perform orthogonal optimization for the parameters in electroplating Zn-Al alloy. The electroplating Zn-Al alloy technology was decided, in which the content of Al is about 12%–15%.

The influence of Cu dopant (x) and sintering temperature (T_s) on the transport properties of La_2/3Ca_1/3Mn_1−xCu_xO₃ series samples prepared by Sol-Gel technique was investigated. X-ray diffraction patterns show that all the samples with different Cu dopant and sintering temperatures (T_s) are of single phase without obvious lattice distortion. Experimental results indicate that the insulator-metal transition temperature is directly related to the sintering temperature and Cu dopant x. It is interesting to observe that a proper amount of Cu dopant can substantially improve magnetoresistance effects.

By using such flier-plate material, quasi-isentropic compression can be realized. Based on it, hypervelocity launching is further accomplished. As a result, an extremely high dynamic pressure can be obtained in laboratory, offering a practical method for the comprehensive determination of materials behavior, response, equation-of-state and properties in dynamic loading process.

It is confirmed that the essential condition for glasses and glass-ceramics to bond to living bone is the formation of an apatite layer on their surfaces in the body. It is proposed that a hydrated silica formed on the surfaces of these materials in the body plays an important role in forming the surface apatite layer, which has noi been proved yet. It is shown experimentally that a pure hydrated silica gel can induce the apatite formation on its surface in a simulated body fluid when its starting pH is increased from 7.2 to 7.4.

The low-voltage-electromagnetic forming was applied to powder compaction. A series of experiments was performed to compact aluminum, copper and tin pwders in an indirect working way. Having compacted high-density powder parts successfully, the authors analyzed the effects of voltage, capacitance, friction, compaction times, powder size and other factors on the densities of compacted specimens. The experimental results show that lower voltage but larger capacitance are beneficial to increasing the density and homogeneity of the compacted specimens, if the loading velocity and discharging energy are suitable. The higher the voltage, the greater the percentage of energy consumed by friction. If the equipment energy is limited, the iterative compaction is an efficient way to manufacture homogeneous and high-density powder parts.

Ag−TiO₂ thin films were prepared on glasses. The morphology and structure of Ag−TiO₂ films were investigated by XRD, SEM and FT-IR. The photocatalytic and hydrophilic properties of Ag−TiO₂ thin films were also evaluated by examining photocatalytic degradation dichlorophos under sunlight illumination and the change of contact angle respectively. The research results show that the Ag−TiO₂ thin film is mainly composed of 20–100 nm Ag and TiO₂ particles. The Ag−TiO₂ thin films possess a super-hydrophilic ability and higher photocatalytic activity than that of pure TiO₂ thin film.

The effects of the grinding mode, fineness, gypsum kinds and dosage, mix proportions on properties of the composite cements consisting of slag, fly ash, limestone and a lower content clinker were investigated, respectively. The results show that when the proportions among slag, fly ash and limestone are appropriate, the grinding technology and system are reasonable, the optimized gypsums and additives are effective, the 52.5R grade cement (52.5R grade cement means a higher strength than 52.5 at early age) can be prepared by clinker dosage of 50% in weight, the 42.5R or 42.5, 32.5 grade composite cement containing 40% and 30% clinker also may be made, respectively. Moreover, the high performance concrete prepared from the above composite cements was studied experimentally.

A series of 0–3 composites of the polyvinylidene fluoride (PVDF) and BaTiO₃ was prepared. BaTiO₃ was modified with titanate coupling agent. The dielectric properties and the interfacial interaction of composites by different preparation methods were examined and compared. The result shows that the relative dielectric constant ∈ of the composite prepared in solution has a maximum value at about 70% weight fraction of BaTiO₃ and the dielectric loss tanδ increases rapidly when the fraction exceeds 70%. For the composite prepared in melt, the relative dielectric constant ε almost reaches a maximum value at about 60% weight fraction of BaTiO₃ and the dielectric loss is comparatively lower. The dielectric properties of composites are improved by using a coupling agent.

Based on sound absorption mechanism of material, the special sound absorption material CEMCOM for road sound insulation is introduced. This high sound absorption material is mainly composed of expanded perlite. Using multiple sound absorption structure can improve sound absorption property of material. According to the preparation principle and durability design of material, a new kind of material with low cost and high durability is developed.

A program control was applied in the fuel gas shuttle kiln, and its principle and disadvantge were analyzed. An advanced set point control method, in which the change rate of temperature is the controlled variable, is also described, and the new control system makes the control precision of temperature improved.

An Al-50wt% TiC composite was directly synthesized by self-propagating high-temperature synthesis (SHS) technology, and then was used as a grain refining master alloy for commercially pure aluminum. the microstructure and grain refining performance of the synthesized master alloy were emphatically investigated. The SHS master alloy only contained submicron TiC particles except for Al matrix. Moreover, TiC particles were relatively free of agglomeration. Grain refining tests show that adding only 0.1 wt% of the master alloys to the aluminum melt could transform the structure of the solidified samples from coarse columnar grains to fine equiaxed grains (average grain size 120 μm), and that this grain refining effectiveness could be maintained for almost 1. 5h at 1003 K. Therefore, it is concluded that the SHS master alloy is an effective grain refiner for aluminum and its alloys, and that it is highly resistant to the grain refining fading encountered with most grain refiners.