Abstract:Continuously reinforced concrete pavement (CRCP) will break into separate slabs in the longitudinal direction a few months after its construction.Based on the calculation results of finite element method (FEM), a simplified formula of separate slab's temperature contraction stress was established by means of orthogonal design and multivariate statistical regression.Range analysis of the calculation results ranked the factors in the order of importance as follows: temperature change, crack spacing, slab thickness, bond-slip stiffness coefficient, bar diameter and bar spacing.Through single-factor and single-variable regression analysis, the general relationship between the temperature contraction stress and each factor was determined.A fitting formula was then obtained by single-variable and multi-factor multivariate statistical regression method through the assumption and combination analysis of each variable.The formula passed the hypothesis test, and error analysis showed that its maximum error range was controlled within 8%.

Abstract:The fatigue properties of RPC (Reactive Powder Concrete) with different steel fiber ratios of 0%, 1.5% and 3% in volume were investigated with the uniaxial compressive fatigue test.The results showed that the splitting failure mode appeared for pure RPC specimens without steel fiber, but the shear failure mode occurred for those specimens with steel fiber of 1.5% or 3% in volume.The fatigue life and strength increased with the increase of steel fiber ratio; the macroscopic damage, ε-n/Nf curves and the evolution of the fatigue deformation modulus of tested RPC experienced three stages.With the increase of steel fiber ratio, the first and third stages of ε-n/Nf curves lengthened，and the fatigue deformation modulus significantly increased with the increase of the steel fiber ratio corresponding to the same n/Nf.It is suggested that the ratio of fatigue deformation modulus to the initial elastic modulus should be 0.7 and 0.75 for the RPC with a steel fiber ratio of 1.5% and 3%, respectively.

Abstract:Based on the deflection theory and equal-substitute beam method, the reasonable rise-span ratio and height-span ratio were suggested.A single-tower suspension bridge was designed according to the proposed rise-span ratio and height-span ratio, and was compared with a three-tower suspension bridge.According to the results, the number of main cables and the tower's construction cost of a single-tower suspension bridge reduced by 14% and 3.5%, respectively, as compared with a three-tower suspension bridge.The ratio of deflection to span, the maximum rotation angle of the main girder and the longitudinal displacement of the tower top in a single-tower suspension bridge are lower than that computed for a three-tower suspension bridge separately under live load.Therefore, a single-tower suspension bridge is more economical and competitive, compared with three-tower suspension bridges.

Abstract:Wind tunnel tests were carried out to measure the wind pressure on the closed flat roof, closed curved roof and retractable roof.The characteristics of mean and fluctuating wind pressure coefficients were particularly studied.The wind pressure fields of the roofs were decomposed in the proper orthogonal decomposition method, and the wind pressure field of flat roof was reconstructed.It has been shown that the performance of POD of oblique wind flat roof behaves best among all the three roofs, retractable roof is second, and closed curved roof is the worst; The overall distribution of mean wind pressure is reflected by the first dominant eigenvectors of POD.The POD reconstruction performance varies a lot among individual taps.The same taps have better performances for more eigenvectors.Different taps have better performances for higher variance taps.

Abstract:The response surface method and an Improved Nondominate Sorting Genetic Algorithm（NSGA-II） were applied to optimize suspension structural parameters.The design parameters' sensitivity was analyzed by ADAMS/Insight.And then, for the greater sensitivity of design parameters, a second-order response surface approximate model ,which explicitly expresses the approximate relationship between the design parameters and the wheel alignment parameters maximum variation in the wheel beating, was established.Finally, the model's stability was analyized and the improved NSGA-II with an elitist preserve strategy and removing duplicates individual algorithm were used to solve the multi-objective optimization problem.The optimization results indicate that these methods have high accuracy and validity.

Abstract:To resolve the problem of inadequate performance of road snowplow of engineering vehicles on current Chinese market, this paper used the theory of TRIZ to study the evolution of road snowplow of engineering vehicles.The theory makes the evolution by resolving the conflicts of snowplow development and design.This paper first analyzed the problems between the road and the vehicle, found the internal conflicts to restrict the evolution and sorts out the conflicts according to the characteristic, and used TRIZ theory to describe this characteristic by general technology parameters.In the second part, the author used conflict matrix and the separation principle to solve the corresponding technological and physical conflict, and found solutions to the inventive principles according to different types of conflict.Finally, according to the principle of the invention and combined with the engineering experience, we obtained the evolution of new snowplow of engineering vehicle programs.The analysis shows this new program of the vehicle has made rapid progress in avoiding obstacle performance, speed of removing snow and adaptability of snow.

Abstract:In order to exploit the potential of energy-saving of blast furnaces in SKS lead smelting systems (hereinafter referred to as SKS blast furnace )，the income and expense distribution of energy and exergy were calculated and analyzed by adopting the energy and exergy analysis approach.The results indicated that the thermal efficiency and the exergy efficiency of the SKS blast furnace is 47.55% and 38.88%, respectively.The efficiencies can be improved by reducing the loss of discharged gas，making use of the energy of cooling water, directly reducing the high lead slag with new techniques.and so on.The thermal efficiency and the exergy efficiency of the SKS blast furnace can reach 71.34% and 43.01%, respectively,by only utilizing the energy of cooling water.The total output of the exergy leaving the SKS blast furnace is much smaller than the total input, and the internal irreversible exergy loss accounts for 41.85% of the total input of exergy.The exergy income of the SKS blast furnace is 1.61 times of the total energy income，which illustrates that the balance of the energy and the exergy have little relevance.Exergy analysis further shows the essential of the consumption of material and energy in systems.Moreover, the exergy analysis is simpler than the energy analysis.

Abstract:Taking a burner-type diesel particulate filter (DPF) as an example and based on the pyrogenation regeneration model, the variety laws of the exhaust back-pressure, particulate layer thickness and wall maximum temperature, etc.during the burner-type DPF regeneration were studied and analyzed under different working parameters, such as oil-spray pressure, spray rate and air-supply flux.The results indicate that the working parameters could influence the regeneration evidently.With the improvement of the oil-spray pressure, the wall maximum temperature increased markedly, and the regeneration rate was quickened.The burner power became stronger with the increase of oil -spray rate, and the amplitude of the wall maximum temperature was greater.But for the safe endurable temperature of DPF, the oil-spray rate must be controlled.When the oil-spray rate reached a certain extent, the oxygen content in the exhaust was deficient, the combustion efficiency decreased, and the soot oxidation velocity and regeneration rate slowed down.It increased the oxygen content by air supply and the regeneration process quickened.But with more air-supply quantity, the regeneration may slow down because of the enhancement of convection transfer heat loss.

Abstract:Based on single machine equal area criterion, the stability margin based on single study generator and reference generator was defined.The power angle curve expression for single study machine was analyzed.Based on the Taylor series, the power angle curve of single study generator can be expressed as the function of the rotor angle of the study generator with respect to the reference machine angle, which is fitted by using polynomial function.The stability margins obtained by both prediction method and post event method were compared.Single Generator Equal Area Criterion(SGEAC) based stability margin is the real evaluation of the global stability margin, and it does not need the identification of the two group mode.Lots of example analysis verified the proposed method.

Abstract:The particle size distribution and Zeta potential of a kind of quaternary ammonium salts emulsified asphalt were investigated, and the effects of the amount of emulsifier and pH value on the storage stability were discussed.The results have shown that the amount of emulsifier and pH value had an obvious influence on the average particle size, Zeta potential and storage stability of the asphalt emulsion.Moreover, the experiment has shown that the optimum amount and pH value of the quaternary ammonium salt was 1.6 wt% and 4 respectively.

Abstract:The preparation of dialkyl diselenides by the reaction of tosylates with disodium diselenide derived from hydrazine reduction of selenium promoted by sodium hydroxide needs high temperature (100 ℃), and this method is only suitable for preparation of the diselenides without functional group.Cesium ion (Cs+) is bulky, and the electrostatic interaction between cesium ion (Cs+) and anion is very weak.So the anion attached to Cs+ has strong alkality and nucleophilicity.The reaction proceeds more readily under mild reactive conditions using alkali of cesium as a catalyst because of the remarkable decline in activation energy.However, CsOH is very expensive compared to KOH. In this paper, according to the principle of ion exchange, using cesium chloride (CsCl) and TBAI as catalysts and dry DMF as solvent, hydrazine reduced selenium promoted by potassium hydroxide, followed by treatment with functional alkyl halide or tosylates at room temperature to afford corresponding diaryl diselenides in high yields.The method not only prepares diselenides containing functional group but has the advantages of mild conditions and high yields.

Abstract:A static adsorption experiment was carried out to investigate the influence of initial concentration, pH, and cationic strength on adsorption of two kinds of quinolone antibiotics (ciprofloxacin and norfloxacin) on montmorillonite.The results showed that the adsorption process of ciprofloxacin and norfloxacin were consistent with pseudo-second-order kinetics, and the adsorption rate constants were 0.063 and 0.024 kg·mg-1·h-1 respectively.Adsorption isotherms were well described by Freundlich equation, and the high lgKf showed strong adsorption ability.When the solution pH was less than the pKa2 of ciprofloxacin and norfloxacin, the adsorption capacity was higher.The adsorption capacity decreased sharply when the solution pH was above the pKa2.Both cationic and zwitterionic forms of ciprofloxacin and norfloxacin could be adsorbed significantly.At higher pH, the complexation of anion on the montmorillonite surface might become the main mechanism.The concentration of Ca2+ had a great influence on adsorption.The higher the concentration, the lower the adsorption capacity of ciprofloxacin and norfloxacin.

Abstract:A transition pixel based detection and localization algorithm was proposed for the artificial texts in the video frame.The transition map was generated by extracting transition pixels in both horizontal and vertical directions.The transition pixels in the background were suppressed by block filtering, and candidate text regions were obtained by intensity based region growing.Finally, the candidate text regions were verified by improved local binary pattern (LBP).Experiment results have shown that, compared with Kim's work, the proposed approach can achieve more accurate text detection and localization.

Abstract:To solve the problem of low efficiency of probabilistic packet marking, an improved algorithm was proposed.This new algorithm optimizes the encoding of path information and modifies the marking and reconstruction process, so that victims can quickly reconstruct the attack path.Simulation results have shown that the new algorithm can effectively reduce combination frequency, improve tracking efficiency and greatly reduce the false positives rate.In the actual denial of service attack, victims can track the attacker faster and more accurately, thus minimizing the damage.

Abstract:The increasing application of WSN (Wireless Sensor Network) brings forward higher and higher requirements on the security of the network.The Sybil is one of the multitudinous security attacks that WSN has to face now and is one of the most ruinous.Based on the analysis of its attacking principle, a type of dispersing guarding algorithm linked with network localization was proposed.The algorithm was used for the measurement of the consistency and the calculation of two methods for the detection of attack nodes, which is different from the traditional centralized guarding mode.The emulation of the algorithm and the experiment results indicate that the algorithm has very good pertinence and robustness against Sybil attack.

Abstract:By using trapdoor functions with preimage sampling, lattice's growth, and lattice basis randomization in the bonsai tree, a lattice-based proxy signature scheme was proposed.The security of the proxy signature is based on the hardness of average-case SIS (Small Integer Solution) and ISIS (Inhomogeneous Small Integer Solution).It is also existential unforgeability under adaptive chosen-message attack in the random oracle.Compared with the schemes based on factoring or discrete log, the public and secret keys of our scheme are larger, but it requires only linear operation on small integers.

Abstract:Considering the many models of nonlinear partial differential equations existing in physics and other fields， the existence of exact travelling wave solutions of equations was proposed． By introducing a wave variable and using the first integral method based on the ring theory of commutative algebra，we have obtained the exact travelling solitary wave solutions for two nonlinear evolution equations.It has many advantages over other traditional techniques, it is direct and concise.It also shows that the first integral method is an effective method with great potentials when finding complex solitary wave solutions of the nonlinear equations．