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SnO2 nanowires with a tetragonal structure were synthesized by thermal evaporation of tin grains at 900 °C. The obtained SnO2 nanowires were doped with Pt and Pd. The morphology, crystal structure, and H2 sensing properties of undoped, Pt-doped, and Pd-doped SnO2 nanowires were investigated. SnO2 nanowires were approximately 30–200 nm in diameter and several tens of micrometers in length. Gas sensors based on undoped, Pt-doped, and Pd-doped SnO2 nanowires showed a reversible response to H2 at an operating temperature of RT–300 °C. The response was improved in the order undoped < Pt-doped < Pd-doped SnO2 nanowire sensors under the same conditions. The highest response upon exposure to 1000 ppm H2 was 252.9 at 100 °C for Pd-doped SnO2 nanowire sensor. The results demonstrated that impurity doping improved the sensor response and lowered the operating temperature at which the sensor response was maximized.

The key technology of electric vehicle battery management lies in the battery state of charge (SOC) estimation, accurate and efficient estimation of SOC can provide the reference data for the control system of the electric vehicle in time. On the basis of the Ah measurement method, Calman filtering method, open circuit voltage method to estimate method, the estimation procedure to estimate the charged battery optimized Calman filtering method, effectively shorten the calculation process, improve the estimation accuracy, in the normal operation of electric vehicles under the influence of comprehensive consideration about the discharge voltage, battery temperature to estimate the state of charge, the Calman filter optimization algorithm, and its application in the electric vehicle battery management system. The experimental results show that, the algorithm can calculate the real-time high charge state of surplus value, provides a set of effective estimation scheme of calculating the battery charge state.

Ultra-High Performance Concrete (UHPC) is a relatively new kind of matierials with excellent mechanical and durability performance compared with the conventional concrete. By making a comparison with the conventional concrete ,the compressive strength of UHPC may reach about 200MPa,which is its significant advantage and potential in applications of bridges. The performance of high tensile strength (especially with some steel fibers) enables the UHPC members to absorb energy and resist impulsive loading. In addition, because of the low porosity, the durability of the material is excellent. Based on collecting and analyzing international research results. the materials and production, and mechanical properties of UHPC were summarized. Together with a general introduction of existing international projects ,the summarization provides a comprehensive reference to further application and development of UHPC products.

For bridge structures using the traditional steel material, some problems are hard to solve, such as corrosion of steel bar and fatigue of steel deck. And the self-weight stress of the traditional high-strength steel as the material of cable stayed and suspension bridges will limit the main span and load-carrying. As a new type of high performance structural material, fiber reinforced plastic (FRP) has many advantages, such as small mass density, high tensile strength, excellent corrosion and fatigue resistant ability. Therefor in recent years, it has attracted much attention by the construction industry. In this paper, characteristics of FRP material are introduced and then applications of FRP material in bridge structures are discussed.

Bridge constructions of crossing wider sea straits allowed the span of suspension bridge to move forward unceasingly, but the self-weight stress of the traditional high-strength steel as the material of main cable accounted for the ratio of allowable stress would be increasing with the growth of main span. That would limit the main span and load-carrying efficiency. Due to its high tensile strength，small mass density，excellent corrosion and fatigue resistant ability, the carbon fiber reinforced polymer(CFRP) was the ideal material for the main cable of suspension bridge. In this paper the limitation spans of two suspension bridge systems were studied by the static analysis and the theoretical formula derived from the ultimate strength of the main cable.

Bridge constructions of crossing wider sea straits allow the span of suspension bridge to move forward unceasingly, but the self-weight stress of the traditional high-strength steel as the material of main cable accounts for the ratio of allowable stress will be increasing with the growth of main span.That will limit the main span and load-carrying efficiency.Due to its high tensile strength,small mass density,excellent corrosion and fatigue resistant ability,the carbon fiber reinforced polymer(CFRP) is the ideal material for the main cable of suspension bridge.In this paper, the feasibility of applying CFRP materials in the suspension bridges was proved and the applicable spans for the suspension bridges with CFRP cables were also provided.

The lattice parameters, phase transition, and thermodynamic properties of OsN2in pyrite and fluorite structure are investigated by first-principles calculations. The pressure and temperature induced phase transitions of OsN2from fluorite structure to pyrite structure have been obtained. It is found that the transition pressure of OsN2at zero temperature is 158.2 GPa, and there exists no transition temperature. In addition, the thermal expansion, the Debye temperature, and the Grüneisen parameter in diverse pressures and temperatures about these two structures have also been obtained. Key words: transition phase; thermodynamic properties; OsN2PACS numbers: 71.15.Mb, 64.70.Kb