Abstract:Most houses in rural areas are low and wide. And the houses often have one or two floors which lack seismic ability. Based on the sufficient research of the steel asphalt isolation layer, we used the special isolation layer for a practical engineering case with three floors, and the isolation layer proved cheap with simple construction and obvious isolation effect. After the structure of the house was finished, we used the hammering method to test the isolation coefficient of the house by putting the vibration pickup style 941B on the basement floor and the first floor. The results showed that the isolation layer could decay the acceleration by about 40%. At the same time, the construction cost of the house did not increase any more at the contrast calculation. Therefore, this new type isolation layer is very suitable to be widely used in rural areas.

Abstract:Two types of terrain categories, C and D, were simulated in a boundary layer wind tunnel, a wind tunnel test was carried out on a tall urban building, and the wind pressure distribution, wind load and wind-induced response of the building model were investigated. The result has indicated that the coefficients of average wind-pressure, overall bending moment, the maximum base shear and the maximum base bending moment under the conditions of terrain categories C are larger than that of terrain categories D.; the wind load of terrain categories C is larger than that of terrain categories D; wind pressure spectral peak corresponds to the frequency of terrain categories C, less than that of terrain categories D; and the accelerated speed of terrain categories C is larger than that of terrain categories D.

Abstract:By simulating the fact circs of project reinforcement, an experimental study in the post-installed pull-out method was conducted for the evaluation of the strength of polypropylene-engineered cementitious composite with five strength grades. We compared the pullout force of PP-ECC with steel mesh with that without steel mesh. The effect of different steel mesh spacing on the pullout force was studied. The feasibility of the method in practical projects was analyzed. Test results have indicated that there is a significant linear correlation between the pullout force of PP-ECC and its compressive strength. The pullout force changes with the steel mesh spacing. The post-installed pullout method has widespread applications in project reinforcement and meets the demand of practical projects.

Abstract:This paper provided a practical method to decide the reasonable spoke cable pre-stress for flexible Ferris wheels. By analyzing the factors influencing spoke cable pre-stress, this paper proposed a method to determine pre-stress value range and a method to adjust the value range, pointing out that the lower limit is determined by the slack of the 0 degree cable, and the upper limit is controlled by the safety factor of the spoke cable. The reduction of wheel weight and spoke cable safety factor can both expand value range, but the increase of spoke cable section area may cause a vicious cycle in spoke cable pre-stress adjustment. Other factors affecting spoke cable pre-stress, including wheel rigidity and cable sag, were also analyzed. Besides, since the mechanical property of flexible Ferris wheels can be generally decided by the ratio R of spoke cable pre-stress and wheel weight, flexible Ferris wheels of different scales can take similar R value as Beijing Great Wheel to decide an approximate pre-stress value.

Abstract:The existing heavy-haul railway concrete simply supported double-T-type beam bridges can not meet the requirements of heavy haul transport. So, a strengthening method of bonding assisted steel beams for the existing heavy-haul railway bridges was put forward. Using the theory of train-track-bridge time-varying system, the spatial dynamic analysis model of train-track-bridge system was set up. And based on the existing heavy-haul railway concrete simply supported double-T-type beam bridge and strengthening method, the dynamic response was analyzed, the dynamic response of bridges at different speed reinforcements was calculated. Comparing the real vehicle testing data with the calculation results, it has been shown that the strengthening method of bonding assisted steel beams can improve the lateral and vertical stiffness of the concrete simply supported double-T-type beam bridge. Therefore, the strengthening method is feasible and reasonable.

Abstract:A crack detection method of concrete bridges was proposed by using digital image technology, and some image processing algorithms, including gray processing of image, calculation of pixel rate, image noise filter, and edge detection of crack, were analyzed and evaluated for the crack detection of concrete surface. Then, a computer program was developed with visual C++6.0 programming language to detect the cracks, which was tested with 15 cases of bridge video images. The results have indicated that this method can effectively detect the width of cracks for reinforced concrete bridges and the B type prestressed concrete bridges. The results have also showed that the relative error is within 6% for the more than 0.3 mm cracks and it is less than 10% for the crack width between 0.2 mm to 0.3 mm.

Abstract:One of the difficulties of the numerical solution of incompressible Navier-Stokes equations is the determination of the pressure field and the fulfillment of the incompressibility condition. In fact, the pressure variable is not present in continuity equation, but a constraint for the velocity field is present. In this paper, the basic variables of velocity and stress were proposed for incompressible viscous fluid, a one-order fluid dynamics equation system without pressure term was proposed and its integral form was given to handle this problem. The stress and the velocity were interpolated by equal order finite element. The Newton iterative method was used to handle the nonlinear convective term. The backward Euler method was used to discretize the time term. A steady flow of incompressible viscous fluid between two infinite parallel plates and a Benchmark problem of incompressible viscous fluid flow around a cylinder were computed on the basis of FreeFem++. The feasibility and the effectivity of the method were verified by comparing with the analytic solution and the Benchmark results respectively. The difficulty of pressure term which is not present in continuity equation is circumvented by using one-order system without pressure term.

Abstract:Because of the special forms of the suspensions of the mining dump truck (MDT), common methods can not be used to solve the problem of “braking nod”. In view of those, based on the neutral plane and the moment center, suspension parallel bench test simulation and vehicle braking simulations were conducted to get the wheels' contact point trajectory and the suspension longitudinal angle stiffness and so on. And then, the value of suspension longitudinal stability coefficient was obtained. It was identified as the target function, and the optimal variables were the suspension parameters, the pitching performance of MDT was optimized. The simulation result has shown that the suspension longitudinal stability coefficient is increased by 19.04%, the nodded size of the front suspension and the pitch angle decreased by 18.23% and 15.25%, respectively. The “braking nod” phenomenon of the mining dump truck was improved noticeably.

Abstract:Considering the huge and transient force in the spool opening process of the hydraulic press, a cam profile curve design method based on the combination of two arcs was presented. The method aims at getting small pressure angles when the driving force reaches its maximum value and getting a fast opening speed in the whole process by finding a suitable combined two-arc curves. The mathematical model of the cam profile was established on the basis of homogeneous coordinate transformation, whose kinematic characteristic was investigated by using equivalent slider crank representation. This method was applied on the cam design of the spool drive system in 300MN die forging hydraulic press. The cam has good flexibility and small impact. Industrial field application shows that the cam designed in this method can effectively reduce the frequency of equipment failures. This method provides guidance for cam design on the condition of heavy and transient load.

Abstract:The microscopic morphologies of uniaxially compressed copper bicrystals (CB) with horizontal and vertical grain boundaries (GB) were observed. Experiment results have shown that, under the same comppressive loading condition and comparing the case of CB sample with horizontal GB, a higher stress exists beside the GB for the CB sample with vertical GB, for which there are much more micro-voids and cracks, whose locations are much concentrated to or beside the slip lines.

Abstract:This paper investigated the sustained effect of central nervous system activities on human brain between traditional manual acupuncture and electro-acupuncture on ST-36 by collecting resting-state functional magnetic resonance imaging (fMRI) data and analyzing the fMRI data. 12 (male/female=6/6, aged from 23 to 27) acupuncture naive, right-handed healthy adult volunteers were chosen and divided into manual acupuncture (MA) group (12 subjects) and electro-acupuncture (EA) group (12 subjects). The needle was rotated bi-directionally at the frequency of 2 Hz for 2 minutes stimulation on ST-36 during MA (2 Hz) and EA (constant square wave, 2 Hz, intensities ranging from 0.5 to 1.4 mA). Statistical results showed that manual acupuncture and electro-acupuncture induced different long-lasting responses after the administration of acupuncture on ST-36.Structures associated with the release of analgesia-related neurotransmitters, including the midbrain and basal ganglia, presented prolonged activities in post-stimulus stage. Different patterns of brain responses between the two modalities may show differences in the transmission channels of meridian and activities in neurotransmitter system.

Abstract:Complicated simultaneous differential equations need to be solved as the result of non-observable quantities in the model of synchronious generator, which leads to difficulty of identification. Firstly, an identification model was derived for synchronious generator completely presented by the observable quantities, in which the quantities of state in the equation of state were represented with measurable quantity, including the outlet current of generator, exciting voltage, exciting current, power angle and increment of rotate speed. Then, the principle of direct integration least square (DILS) was utilized to identify the parameters of generator based on this model, which avoided the solution of complicated differential equation and simplified the method for parameter identification. Finally, a simulation sample was calculated in the MATLAB and the results showed that the identification model and algorithm were correct, feasible and effective.

Abstract:Aluminium-based composites containing 7%, 13% ,20%Si contents and 15vol% of SiCp were fabricated by spray deposition technique and followed by hot extrusion. The dry sliding wear performance of SiCP/Al-Si composites was investigated. Dry sliding wear tests have been performed using a block-on-ring type apparatus under different normal loads of 10, 50, 100,120,150,200 and 220 N and at a constant sliding speed of 1 m/s. The microstructures, morphologies and phases of worn Surfaces were analyzed by optical microscope (OM), scanning electron microscope (SEM) and energy-dispersive X-ray microanalysis (EDX), respectively.The results have shown that Al-20%Si/SiCp composite has better wear properties in the applied load range and the transition load increases with silicon content increasing. At low test load (50 N), the main wear mechanism is oxidation wear and abrasive wear for three composites. Adhesive wear becomes the main wear mechanism for SiCp/Al-7Si at 120 N and SiCp/Al-13Si at 200 N. But for SiCp/Al-20Si at 220 N, the main wear mechanism is still oxidation wear, and has a minor adhesive wear.

Abstract:CAE Integration Platform based on Super Computation can solve some problems in industrial products design, such as CAE software integration, calculation speed and parallel computer using. This paper proposed the overall structure and the overall architecture of the platform for development. The platform consists of 5 layers and 7 subsystems. The front end system adopts SSH architecture, ESB bus and middleware uses Spring, Hibernate and Tuscany combination. Cluster system is mainly on the “Tianhe No.1” super computer scheduling system improvements. According to the overall architecture design, the prototype platform was developed.

Abstract:On the basis of the current adaptive constraint solving algorithms, this paper proposed a new adaptive constraint propagation solving algorithm ADAPTAC-LmaxRPC, which adaptively switches between enforcing a strong and expensive local consistency LmaxRPC and a weak but more cheaper one AC according to the activity of individual constraints. Test data from several Benchmark instances shows that ADAPTAC-LmaxRPC balances the contradiction between the constraint solving efficiency and algorithm cost effectively, and it improves the efficiency of constraint solving substantially.

Abstract:This paper, we considered the rank range of the least-squares solutions of matrix equation AXB=C. By applying the singular value decomposition of matrix and the properties of Frobenius matrix norm, we have obtained the range of the rank and the least-squares solution expression of under rank constrained. Finally, we have provided the expressions of the least-squares solutions with maximal and minimum rank respectively.

Abstract:The problem of multivariate polynomial coprime was studied, where multivariate polynomial is in polynomial rings over unique factorization domain. From the classical definition of resulatants and combining the property proposed, we obtained the necessary and sufficient condition to judge whether multivariate polynomials are coprime polynomials or not, and whether there is a common factor of positive degree in these polynomials or not.

Abstract:The experimental economics method was utilized to examine the effects of buyer demand information transmission on the results and process of housing search. Firstly, based on the asymmetric information theory and the multi-attribute reverse auction theory, two hypotheses with reference to the effects of buyer demand information transmission on the result and process of housing search were proposed for test. Secondly, according to the characteristics of actual housing search process, three treatment housing search experiments were designed and conducted in laboratory. Thirdly, utilizing the experimental data, nonparametric tests were implemented for the best of two hypotheses. The findings indicated that the match degree has positive correlation with the buyer demand information transmission while the attribute competition has negative correlation with the amount of buyer demand information transmission. Besides, there is no significant effect of buyer demand information transmission on the buyer's earnings, the broker's earnings, the search duration and the price competition. In conclusion, the transmission of buyer demand information can help buyers to search more suitable houses without negative effects on the search results.

Abstract:From the standpoint of traditional DEA model and taking environmental pollution outputs into account, according to Chinese provincial panel data from 2005 to 2010, we have analyzed China's energy efficiency by using different cross-evaluation methods. The results have shown the low-level of China's energy efficiency and significant differences of provincial energy efficiency. Besides, there is a pattern of high energy efficiency in the eastern region and low energy efficiency in the western region. In addition, China's energy efficiency has an upward trend during the 11th Five-Year Plan, but the gap of energy efficiency between eastern and western regions has a trend of widening.