Applied Mechanics and Materials Vol. 142

Abstract: When establishing the prestressed bridge model with the entity unit, the simulation of prestress bar has very big limitation. The paper takes 20 nodes isoparametric element as an example and puts forward a kind of numerical method combined with the Newton iterative algorithm and Gauss integral algorithm to calculate equivalent loads of prestress in body element. This method can be used to calculate the equivalent loads of prestress in the various complex steel in bundle shapes and suits the computer programming. Through the final regular inspection, this method has been proved to have very high precision.

Abstract: The interaction between femtoseocnd laser and transparent materials has been studied intensively in recent years. When the femtosecond laser was focused onto the surface of the transparent materials, if the laser fluence applied to the sample exceeds the material’s fluence threshold, ablation occurs. In this paper, we study the surface ablation of lithium niobate by femtosecond laser. We produced a two-dimensional array of voids in the sample surface by varying the number of shots and laser energy, and analyze of the damage depth with the relation to the pulse energy and the number of the pulse. It has important reference on the microfabrication in such materials by femtosecond laser.

Abstract: In this paper a phase transformation equation is supposed to describe the phase transformation behaviors of the shape memory alloy (SMA) under complex stress state. The stress field near crack-tip of mode I in SMA at various temperatures is investigated based on the supposed phase transformation equation and linear elastic fracture mechanics. Results show both the martensite region and the mixed region of martensite and austenite near the crack-tip become larger with the decrease of temperature. The fracture mechanics behaviors of SMA are much influenced by the temperature.

Abstract: This study coats complex colloid mixed with Sn-xAl powders and polyethylene on glass to examine the shield effect on electromagnetic interference (EMI). In addition, the sputtering specimens and powder coating specimens were compared. The results show that adding Al to the Sn-xAl powders can increase the electromagnetic interference (EMI) shield at lower frequencies. Notably, the number of cavities in the coating layer increased with the coating thickness, with the result that the EMI shield could not improve with an increase in the coating thickness at higher frequencies. However, the EMI shield of sputtering films had a tendency to increase as the thin thickness increased. The Sn-40Al undergoes a dispersing effect which forms a fine overlapping structure, thereby improving the low frequency EMI shielding. In addition, the Sn-20Al powders possessed the properties of a small particle size, closed structure and higher electric conductivity which improved the high frequency EMI shielding. For the sputtering films, the annealed treatment not only had higher electric conductivity but also increased the high frequency EMI shielding.

Abstract: Changes of the content of starch, amylose and the activities of 3 key enzymes involved in starch synthetic metabolism in developing rice grains under four different temperature in phytotrons during grain filling stage of two aromatic rice varieties were studied. The results showed that compared with that under the lower temperature (21°C and 23°C), the content of starch and amylose and the activities of SBE and GBSS under higher temperatures (26°Cand 30°C) were generally higher at the beginning of the grain filling stage and obviously lower during the middle and late grain filling stage, with the exception of the activity SSS which were always higher under lower temperature. The relationship between the changes of activities of SSS, SBE and the variation of starch accumulating rate was very close and so did the relationship between GBSS activity and the amylose content. The lower activities of SSS, SBE and GBSS during the middle and late grain filling stage may be the key physiological factors which lead to the poorer progress quality and appearance quality of aromatic rice under high temperature.

Abstract: Accoding to the current situation of deck surfacing with Epoxy asphalt and its development in China and abroad, this paper has analyzed the feature of the function of Epoxy asphalt used on surface pavement of cement concrete bridge through analyzing the physical and chemical properties of Epoxy asphalt and further testing the superiority of Epoxy asphalt in the road construction.

Abstract: This paper starts with the mineral structure, reducing properties of chromium ore and the physical and chemical properties of chromium oxide and discusses the requirements of the chemical composition of chromite and confirms the selection principle of chromium ore and reducing agent of chromium ore smelting reduction. The chemical compositions of the available chromite request the relatively high contents of chromium and iron, the lower contents of Al₂O₃, MgO and P in gangue and the lower Cr/Fe ratio in keeping with the case of high chromium. Chromoium ore in South Africa is considered to be suitable for smelting stainless steel crude melts in a smelting reduction converter. From the reducing power and economy angle, carbon as a reducing agent is more suited to reducing chromium ore.

Abstract: The secondary effluent of WWTPs can be treated by the coagulation advancedly. The laboratory results showed that, PFS and PAC had lower efficient for the treatment of pollutants, and the effluent can not meet the requirements, so they were not s uitable as the coagulant. The PSFA, produced by the laboratory, had a higher removal rate of pollutants, and the quality of effluent can meet the relevant requirements of the standards, so it can be used as the coagulant of advanced treatment. The results of the experiment showed that the optimal dosage of PSFA was 20mg/L, and the COD, SS, turbidity, chromaticity, and TP of effluent were 9.5mg/L, 4.9mg/L, 2.7NTU, 10times and 0.15mg/L respectively.

Abstract: The use of rubber asphalt pavement as a bridge deck waterproofing adhesive layer material, the use of shear test and pull-out test analysis of the adhesive layer of rubber bitumen adhesive properties. The best rubber asphalt spraying volume has been tested, and the stress - deformation of rubber asphalt waterproofing adhesive layer has been obtained. Studies have shown that rubber asphalt has good deformation ability, suitable for bridge deck waterproofing adhesive layer materials.

Abstract: A substrate culture experiment was conducted to study the effect of different biological organic fertilizer levels (control: zero fertilization, low level, medium level and high level) on plant growth and yield of Chinese kale (Brassica alboglabra Bailey). Results showed that compared with control, treatments of medium and high fertilization increased the leaf number, plant height, stem diameter, yield and plant dry matter of Chinese kale. Thus they promoted plant growth. The fertilizer utilization ratio of Chinese kale was the lowest for low fertilization treatment, and it was the highest for medium fertilization treatment, while it was decreased for high fertilization treatment. The treatment of medium level fertilization (30g/plant) promoted plant growth and increased the yield of Chinese kale; also it had the highest fertilizer use efficiency. So it was the appropriate organic fertilization amount for Chinese kale production.