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Recently, noble metal nanoparticles (Au or Ag NPs) decorated graphene (GE) sheets are used as good surface-enhanced Raman scattering (SERS) substrates for detection of molecules. Ultrathin GE film covered by Ag NPs has been designed for the SERS substrate in this paper. The films were prepared firstly by dip-coating method with graphene oxide (GO) and AgNO3 or Ag NPs colloid as raw materials and secondly reduced by thermal annealing at 600 °C in H2/Ar atmosphere. The structure and SERS activity of the obtained films have been investigated in detail. Results indicated that Ag NPs can be decorated on graphene sheets through the electrostatic adsorption between the GO sheets and positively charged Ag+ or Ag NPs. Compared with the film obtained with AgNO3, Ag NPs/GE film prepared with Ag NPs colloid showed the higher SERS sensitivity with rhodamine 6G (R6G) as the probing molecules, the enhanced factor for 1×10-5 M of R6G adsorbed on the surface of Ag NPs/GE substrate is about 9.1×107.

In this article a surrogate model between suspension system parameters of tracked vehicle and comfort evaluation indices has been built up by using radial basis function method and the dynamic simulation of tracked vehicle. Then the optimization of suspension system parameters has been carried out by using surrogate model and adaptive simulated annealing optimization arithmetic. The results show that the research method is feasible.

In this paper, we have considered a viral infection model with delayed CTL response and cure rate. For this model, we have researched the stability of these three equilibriums depend on two threshold parameters and , that is, if , the infected-free equilibrium is locally asymptotically stable; if , the infected equilibrium without CTL response is globally asymptotically stable; and if , the infected equilibrium exists, at he same time, we have found that the time delay can lead to Hopf bifurcations and stable periodic solutions when the is unstable.

The vibration character is analyzed with the methods of harmonic wavelet and time domain indexes of reconstruction with simulation signal and test data. Using harmonic wavelet compactly supported characteristic and box spectrum, the data is rebuild with some specific frequency wavelet coefficients. This not only realized the frequency domain filtering, the time domain information is also retained. The analysis of time domain indexes shows the method can identify the vibration amplitude growth derived from the noise or from the useful signals. The simulation and experimental results confirm that, with the harmonic wavelet reconstruction signal time domain indexes, the gear fault detection and diagnosis can be achieved under the condition of strong noise.

Directly mixing the PCM to asphalt mixture may adversely affect mixture performance. By the experiment of SEM, the diffusion-absorption circle testing and the DSC, the micro-morphology and the adsorption characteristics to PCM of four carriers and the thermal properties of the composite shape-stabilized phase change materials (CSPCM) were analyzed. The results showed that the activated carbon, the floating bead and the white carbon black have more developed porous structure. The white carbon black has the best effect on the adsorption of PCM. The shape-stabilized PCM prepared by the physical adsorption method has the leakage problem. The CSPCM with the white carbon black carrier has the best heat storage capacity. The white carbon black is the best carrier of PCM for asphalt mixture.

Non-magnetic steels are required in energy and transportation fields such as superconducting energy storage equipment, magnetic liquid power generation equipment, superconducting generators, superconducting power transmission and ship electromagnetic propulsion. Experimental research on steel making, hot rolling, solution and aging for non-magnetic steel 30Mn27Al4V was carried out in the laboratory. The microstructure evolution was observed and the mechanical property and relative magnetic permeability were tested after heat treatment. The effects of fine particles such as VC, VN and V(CN) dispersively distributed in austenite matrix on precipitation, grain refinement and austenitic nucleation were analyzed. The microstructure of the tested steel is austenite. The grain size is 24~28μm. At room temperature, the yield strength and tension strength are 556 MPa and 701 MPa, elongation after fracture of the steel is 47%, the yield ratio is 0.79, strength and ductility product is 32.9 GPa%. After solution and aging treatment, the steel shows a yield strength of 325~371 MPa, tension strength of 550~645 MPa, elongation of 58~78 %, a yield ratio of 0.54~0.60, strength and ductility product of 36.3~46.3 GPa%. The relative magnetic permeability is below 1.005. The results indicate that the tested steel exhibits good mechanical property and non-magnetism. It has no elements of Ni and Cr, so it just needs simple process flow and lower production cost. The numerous applications of the steel in industry can create great economic benefits.

In this study, the combustion behaviors of three kinds of coal and their mixtures under the pure oxygen and air atmosphere were studied by using a thermo-gravimetric analyzer. The combustion characteristics such as ignition and burnout behavior were investigated in the temperature from 20°C to 800°C. The influence of mixing Shenhua coal with Huaibei bituminous and Sanming anthracite coal on combustion characteristics was conduced. The results obtained show that pure oxygen content accelerated the coal burning process greatly; the coal volatile matter started to release at a lower temperature and the coal burning process was finished earlier compared with the burning process under the air atmosphere. The addition of Shenhua coal improved the combustion characteristics of both Huaibei bituminous coal and Sanming anthracite in a different way. For the Huaibei bituminous coal, both the ignition and burnout temperature decreased linearly with the increasing ratio of Shenhua coal; while for the Sanming anthracite, the addition of Shenhua coal greatly lowered the mixture ignition temperature, and the burnout temperature was nearly the same. The activation energy of the mixture coal with Shenhua and Huaibei coal reduced with the ratio of Shenhua coal. For the Shenhua and Sanming coal mixture, the activation energy changed differently at the two burning stages.

It provides a new way to solve the worldwide the low-temperature cracking and high temperature rutting distresses of the asphalt pavement, by mixing the composite shape-stabilized phase change material (CSPCM) to asphalt mixture. The effect of CSPCM on the temperature of asphalt mixture is analyzed by the monotonic cooling test, the monotonic heating test and the outdoor simulating cycle test. The results of monotonic cooling and heating tests indicate that mixing CSPCM into asphalt mixture can increase the temperature of asphalt mixture during cooling process and decrease the temperature of asphalt mixture during heating process. It has a temperature damping effect as well. The results of outdoor simulation test shows that mixing CSPCM into asphalt mixture decreases the maximum temperature of the bottom of the specimen and increases the minimum temperature of the bottom of the specimen. It cannot change the critical temperature occurring time of the bottom of the specimen. The test results indicate that mixing CSPCM into asphalt mixture could actively adjust the working temperature of asphalt mixture, prolong the ideal temperature of asphalt mixture and improve asphalt mixture’s adaptability to the changing environment.

Concrete interlocking block pavement is characterized of preferred durability, easy construction and maintenance and low construction cost. It can be widely applied in the rural highway. Based with the project of rural highway in Tongchuan Shaanxi province, the paper studies the mechanism of interlocking blocks, design of the pavement, and construction technology for field application. After one year service for open traffic, the interlocking block pavement is shown to have fascinating economy and service performance for the rural road.

Mixing the composite phase change material (CPCM) to asphalt mixture is a new way to solve the worldwide problem of the low-temperature cracking and high temperature rutting of the asphalt pavement. Asphalt mixture with CPCM can remain in the ideal working temperature range for a relatively long time. This paper analyzes the influence of the contents of CPCM on its road performance by laboratory testing. The study shows that mixing CPCM to asphalt mixture had little effect to the optimal asphalt content. For CPCM prepared by polymer shape-stabilized method, the high-temperature stability and the water stability of asphalt mixture increases firstly and then decreases the low-temperature anti-cracking stability decreases firstly and then increases with the increasing of CPCM. For CPCM prepared by carrier-adsorbed packaging process, the high-temperature stability decreases, low-temperature anti-cracking stability decreases firstly and then increases, the water stability increases firstly and then decreases with increasing of CPCM. The results indicate that CPCM has significant influences on its road performance. The optimal content of CPCM is around 0.3%.

Finite element analysis (FEA) method is used to study the mechanical properties of headed studs for composite truss joint. The results show that the shear forces in the first few rows of headed studs are much greater than others. The shear forces in the rear headed studs decrease gradually. This study shows that the stiffness of headed studs, the layout of headed studs, and the steel backing plate are the main influencing factors on shear forces of headed studs. It is also expected that the results presented in this paper would be useful as references for the further research and the design of composite truss bridge and composite joint.

Traditional lead brass is gradually prevented from application by many countries’ governments because lead does harm to human health and pollutes the environment. New types of environment-friendly lead-free brass with favorable machinability are urgently demanded in the electrical, electronics and plumping fields. Lead-free Mg-Sb brass was fabricated in present. Experimental results showed that when the content of Mg is 1.0wt%, Sb is 0.8wt% and Cu is 58.0~59.0wt%, the alloy’s mechanical properties and machinability are favorable for industry application. With the increase of the content of Sb, the machinability increased, while the mechanical properties decreased. Lots of Cu2Mg and Cu9Sb2 particles on the order of microns exist in the inner-grain and grain boundaries. These particles improve the machinability, however, lower the tensile strength and the elongation. A three-way pipe joint was successfully punched with the fabricated Mg-Sb brass bar, and this demonstrated that the fabricated Mg-Sb brass possesses favorable hot working property.

A soft rock is generally prohibited to be used as filling material for highway subgrade. A novel method for improving the performance of subgrade is proposed. Aiming at the large amount of highly weathered soft rock along Shiyan-Tianshui superhighway, the physical and mechanical properties of the natural soft rock is analyzed. Then the cement is mixed into the soft rock as filling material to better the subgrade performance.The field and indoor experiments showed that the maximum dry density and optimum water content increases when the cement content increases. By mixing the cement, the subgrade performance can be significantly improved.

With Monte-Carlo theorem, inclusive of the uncertainty of double phase geo-material parameters as well as math model boundary condition, stochastic difference math model was carried out for bulk terrestrial underground water seepage on the basis of plain confined steady underground water flow math model. The key conclusions are: seepage field behavior has close relation with turbulence of random B.C.; distribution of stochastic head potential depends on the geo-born-variation of parameters and the methods introduced in this paper are applicable for this achievement.

The application of Phase Change Material (PCM) to asphalt mixture can lighten the temperature-dependent disease of the asphalt pavement and improve the usability as well as extend the operating life of it. We choose agreeable PCM with comprehensive consideration to the technical requirement of its application in the construction industry and the characteristic of asphalt mixture. Through simulating temperature experiment, we make a conclusion that incorporate the carrier accompanied PCM into asphalt mixture can reduce the increasing rate and cooling rate of the mixture, which shows that PCM can put into use of adjusting the asphalt mixture operating temperature, softening the negative influence of ambient temperature variation on asphalt mixture.

The main span is the steel truss and the side spans are the composite truss in Minpu Bridge. A 1:2.5 model is made to study the mechanical behavior of the joint segment of steel truss and composite truss. Both a model test and a numerical finite element analysis(FEA) method have been conducted. The results show that the joint segment remains in a linear elastic state under the condition. The maximum stress in the structure is less than the material allowable strength. The FEA results are in very good agreement with those of model test. This study shows that the force transformation of the joint segment is reliable and the composition details are rational. It is also expected that the results presented in this paper would be useful as references for the further research and the design of composite truss bridge and joint segment.