Advanced Materials Research Vols. 378-379

Abstract: Permeability coefficient is one of the important hydrogeololgy parameters on dewatering design. Owing to complexity of hydrogeololgy and diversity of calculation, there is much difference in calculated values of permeability coefficient. This paper takes the case of pumping test on steady flow in completely penetrating well at underground station of Zhengzhou-Xinzheng airport route, the test result is analyzed and calculated with the whole process and multi-methods, and then the permeability coefficient of soil horizon is determined comprehensively with some reference value.

Abstract: Constant vertical wind disturbance is a kind of important disturbance form. This form will bring big effect on keeping and controlling aero attitude angle and altitude. Based on established aero sport mathematics models with constant vertical wind disturbance, the structure principle diagram of aero angular displacement control system is founded. Based on MATLAB, simulation researches were emphases done on performance influence of aero angular displacement control system by different disturbance wind speed and disturbance time length. Simulation results show: aerocraft control system performance is greater impacted on constant vertical wind disturbance.

Abstract: In order to solve the problem of aeolian sand subgrade compaction, we studied the technology of impact compaction, applied it to the engineering practice and analyzed its effect with Rayleigh wave. The technology of impact compaction can combine the compaction of potential energy and kinetic energy and make it easier for the materials to reach their elastic stage. With the combined function of "knead-roll-impact", the impact compaction road roller can compact the soil body and offer 6～10 times impact force and 3～4 times the depth of influence more than the vibratory roller. The impact compaction methods of aeolian sand subgrade were put forward. The comparative field compaction tests between impact and vibratory compaction are carried through, which are detected by Rayleigh wave. The results show that the impact compaction can make the density of the aeolian sand subgrade 2～5% higher than the vibratory compaction, and reach the influence depth of 7 metres. To sum up, the impact compaction can clearly increases the strength and stiffness of aeolian sand subgrade with a dynamic elastic modulus of 202.63MPa.

Abstract: The reinforced RC girder with external prestress is applied more and more widely. Reinforcement of the girder is influenced by various factors, among which the concrete intensity degree and the prestress degree are mainly analyzed through the finite element software ABAQUS to learn their influence on the anti-bending bearing capacity of the externally reinforced RC simply supported beam. Since the reinforcement stresses of RC girder (regular reinforced concrete beam) are far less than the maximum intensity of the reinforcing steel bar, the concrete in the pulled area cracks, which causes the stiffness of constructional elements to decrease, deform and expand so that the elements become useless before it is damaged. External prestress can effectively improve such defect of the RC girder, and a great deal of research has been carried out. Due to the experimental boundedness and discreteness, large general finite element software ABAQUS is adopted to analyze the anti-bending bearing capacity of the externally reinforced RC girder, which is based on the size of experimental constructional elements in literature.

Abstract: Strong earthquakes (>7.0 Ms) critically change pedosphere, how the changed soils disturb tree root growth related to forest restoration is unclear globally. Therefore, a total of 15 plots were established in non-removed and landslide areas of Cupressus funebris and Cryptomeria fortunei plantations near northern section of fault belt of Wenchuan Earthquake (8.0 Ms) occurring in May 12, 2008, China. 112 and 114 small fine roots (≤2.0 mm in diameter) in all the plots were sampled in June and October of 2009. Mean tips length/length, area/ length, volume/length, mean tips length/biomass, specific root area and specific root length in 0.0–0.5, >0.5–1.0 and >1.0–2.0 mm diameters of roots were examined. This study revealed 1) root parameters did not respond to the landslide soils in the June, but did until the October, suggesting after many root tips and tiny roots die in winter, the roots lose sensitivity to a changing soil environment; 2) mean tips length/length and mean tips length/biomass decreased for Cupressus funebris, and increased for Cryptomeria fortunei as well as area/length and volume/length in the landslide soils, implying both species roots have different processes of forest restoration; 3) the smallest sized roots were more sensitive to the landslide soils than the other sized roots, which are better indicators for the forest restoration.

Abstract: A coupled modeling system has been developed to describe the mineral dust cycle in the atmosphere. It is composed of MM5, ECIP, WE (wind erosion model) and CMAQ. A strong dust storm of North China in 2002 is simulated by this system. The modeled results show good consistent with observations and pre-existing researches in aspects of dust emission flux in source regions, distributions , vertical profiles and time variation of dust aerosol. Therefore, it can be used for further study on Asian dust storms. Furthermore, this system can be developed for further studies of the impact of dust aerosols on air quality.

Abstract: The aim of this study was to quantify the properties of sludge from iron and steel industry with high content of heavy metals, which has been solidified/stabilised by coal fly ash and Portland cement. The mixtures of sludge and coal fly ash and/or cement after of curing were used for tests. The porosity and permeability characteristics of solidified sludge were examined. To understand the behaviour of mixtures in the long term, the prepared mixtures were tested after 14, 28, 56 and 120 days.

Abstract: The method in this paper the efficiency and reusability of the flow simulation algorithm be significantly improved. We put forward a specific example to demonstrate the application of this method to groundwater simulation. Numerical simulation results can let researchers in VR walked into the model, and to help decision, the investigation, forecast and the management of natural resources.

Abstract: It was the first in China that an attempt was made at screening houseplants to remove ammonia from indoor air. A fumigation system was used to screen 86 species and cultivars at 7.0 mg/m3 of ammonia in the initial screening experiment. Then 9 species of plants were chosen for replication experiment to confirm and quantify the removal effects. Plants in Ericales order showed a promising potential for removing ammonia and further study was suggested. Finally, Nephrolepis exaltata ‘Bostonniensis’ and Plectranthus oertendahlii were fumigated in day-and-night experiment. And the trends of removal rates of ammonia dependence on fumigation time were predicted as cubic functions for both species.

Abstract: To analyse and research the idle hydrocarbon emission regularity of passenger car gasoline engine, based on large sample detected data of different type cars, parameter estimation and hypothesis test are carried on by statistical tools and neans, and the optimum distribution parameters of idle hydrocarbon emission of different type engines are also got. Then the optimum distribution models of these engines are established. The calculating result shows that the maximum error between model calculating and sample detecting certification rates is only 0.526 8%, and the established models have very high calculating precision and practical value. On the other hand, the research also shows that the inspect and maintenance program should be strengthen in order to control vehicle emission pollution effectively.