Abstract: In order to find out the mechanics behaviors of the inclined CFST stub columns which are used in some real engineering projects, a series of tests are performed and a total of 6 specimens with circular section were experimented. The main parameters were the inclined angle (0 degree and 9 degree) and with or without infilling concrete. Comparisons between measured sectional strengths and predicted sectional strengths using the existing codes were made. The results show that the circular inclined CFST stub columns behaved in a ductile manner and all the codes were conservative and available for predicting the capacities of the specimens.
Abstract: In this paper, the three straight casing tubes and the double helix casing tubes were modeled using the Gambit software. And the fluid flowing in tubes was simulated by Fluent software. According to the simulation results, with the field synergy principle, two casing tubes’ flow and temperature distribution of carbon dioxide and water have been analyzed. Simulation data show that the double helix casing tubes is better than the three straight casing tubes on heat transfer and synergy. Lay the good foundation for design optimization and efficiency of heat exchanger of carbon dioxide heat pump system.
Abstract: Experiments were conducted to study the basic properties of steel fiber reinforced lightweight aggregate concrete (SFLAC) mixed with machine-made sand and expanded-shale. The effects of sand ratio and cement content on the cubic and axial compressive strengths, splitting and axial tensile strengths, flexural tensile strength as well as compressive and tensile elastic modulus of SFLAC are analyzed comparing with those of LAC in the same conditions. Data from the experiments shows that, the steel fiber has advantages to every mechanical properties of LAC especially to the tensile strengths, and also modifies the abruptness failure states of LAC into multi-cracked characteristics of SFLAC. The optimum mix proportion is suggested for getting better properties of SFLAC.
Abstract: An analytical method based on rough set theory is put forward to judge disease genesis of cement concrete pavement, in which a decision table of disease genesis based on rough set theory is built according to statistical data of pavement disease in special segment. The support degree of each factor is computed by the attribute reduction algorithm of rough set theory to estimate its influence on pavement disease. The feasibility of the method is illustrated by an example, which makes up the shortages of present practical methods of the pavement disease genetic analysis and provides scientific judgment for maintenance decision of pavement.
Abstract: The corrosion is one kind of major damage mechanisms of airplane structure and is also one of the primary causes resulting in flight failure and disaster .The aim of this paper is to analyze the effect of corrosion time on denudation depth, mass loss and the total depth of corrosion damage. Meanwhile, the three parameters have significant influence on residual fatigue life of aluminum alloy, the residual fatigue life of the aluminum alloy is of great difference between shot peening and without shot peening aluminum alloy. Then residual fatigue life tests are carried on Instron 8801 for the shot peening and without shot peening aluminum alloy. Based on contrast analysis of the experimental results, valuable conclusions are obtained: with the increase of the denudation depth, mass loss and the total depth of corrosion damage, fatigue life reduce continuously respectively; Fatigue life decreases rapidly when the denudation depth is in the range of 0.12～0.17mm.
Abstract: Spinel Li4Ti5O12 exhibits inadequate electronic conductivities that negatively impact its electrochemical performance, this disadvantage limits its commerical use in high current applications for future hybrid electric vehicles. Li4Ti5O12/C has been examined in order to improved the electronic conductivities. Different sucrose additions at m(sucrose)/m(Li4Ti5O12) = 5%, 10%, 15% are investigated along with the structure and electrochemical performances. The results show that the best sucrose addtion is 10%, when sintered at this condition, the distribution of particles size and electrochemical performance of the compound are the most satisfying. When charged at 0.5 C, the initial discharge capacity is 167.72 mAh•g-1, and the initial charge capacity is 162.28 mAh•g-1, and it shows the longest and flattest discharge performance among the three synthesized samples.
Abstract: Skin color detection is an important in computer vision.This work presents a new efficient method for skin color detection based on an improved direct least square ellipse fitting in the space CrCbCg. The color distribution statistics of three-dimensional CrCbCg is obtained by fitting the color distribution ellipse boundary in the Cr-Cb, Cr-Cg, Cb-Cg plane exactly ,finally ,the criteria based on the statistics is used to detect skin color area accurately. Experimental results show that this method improves the robustness of the skin color detection to complex environment.
Abstract: Reservoir plane features of Hei 49 block in Daqingzi Oilfield is analyzed with multiattribute analysis. Through the production of fine synthetic seismograms, the block is analyzed by non-linear multiattribute. The authors set up the relationship between the log information and and the multi-attribute, and this relationship will calculate the seismic properties of theogram demarcation and extrapolate well curve. The way is used to establish statistical relationships by nonlinear artificial neural network. Therefore, seismic attribute volume can be transformed into a variety of reservoir parameter data volume. The method to establish relations between seismic attributes and reservoir parameters overcome the problem of inversion's multiple solutions caused by the geological model and seismic wavelet, and it is a more realistic prediction for this block's reservoir prediction and description.
Abstract: Experiments were conducted to study the mechanical properties and water permeability of recycled aggregate porous concrete. The orthogonal test was designed considering four parameters including water to cement ratio, cement content, grain series of recycled aggregate and aggregate to cement ratio, each parameter was set at three levels. Performances of porous concrete were measured such as cubic compressive strength, flexural strength, continuous porosity and water penetration coefficient. Test results are analyzed on the basis of orthogonal test method, the optimum proportions corresponding to every test parameters are given out. The ranges of every test parameters are also proposed. It provides a reference for constructing porous concrete roads by recycled aggregate made of old concrete from dismantled buildings.