08 February 2013, Volume 31 Issue 4
    

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    Articles
  • WANG Shuli;ZHENG Mianping
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    The wide distribution of the Cambrian rock gypsum and salt is an important feature of older strata in Asia. The Cambrian salt-bearing sequences are mainly distributed in East Siberia of Russia, Iran, Oman, India, Pakistan, and China. Potash salts are also found in East Siberia, Iran, India, and Pakistan. The nature of the tectonic basement is a key controlling factor for the formation of potash basins. The stable tectonic region is favorable for the potash concentration in a quasi-stable region, and the quasi-stability is favorable for the salt concentration and the potash formation in a local stable tectonic region. For example, one of the largest potash deposits in the world--the Siberian Nepa potash deposit-was formed in the Early Cambrian in the palae-depression of Precambrian strata. China's major ancient saline basins are in quasi-cratons (continental block) with the Precambrian basement. In China, only one solid potash deposit in Yunnan can be exploited. However, there are a number of marine evaporite basins, so the study of marine evaporite basins is an important way to solve the problem of serious shortages of potash in China. In recent years, with the exploration of oil and natural gas and the development of the salt industry in China, the drilling has uncovered extensive gypsum and salt deposits in Cambrian strata. Four large marine evaporite basins were found in China. In this paper, through the lithofacies-paleogeographic analysis and the potash geological survey, extensive thick rock salt deposits are found in the Yangtze block and the Tarim block, where good and pronounced anomalies of high Br/Cl and K/Cl coefficients were identified. The Chengkou-Wuxi area of the Yangtze and the Tazhong area of the Tarim block are important areas for potash explorations in the Cambrian, and merit a further study. They provide some important information for carrying out the halite and potash explorations in Cambrian evaporite basins in China.
  • ZHAO Guoyan;WANG Shan;WANG Jiang
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    Based on the mathematical theory of discriminant analysis method, the Fisher's discriminant analysis model is applied to select support pattern for mining roadway in fully mechanized caving face, eight indexes reflecting the selection of support pattern, that is, surrounding rock intensity, coal seam intensity, mining depth, joint and crack of surrounding rock, mining influence coefficient, top coal thickness, coal pillar width, and section area of roadway are taken as the discriminant factors of Fisher's discriminant analysis model. Discriminant functions are obtained by training a large set of expansive samples. The results show that the forecasting model of Fisher's discriminant analysis has the excellent classification performance, high prediction accuracy, and is an effective method for selecting support pattern for the mining roadway in fully mechanized caving face.
  • HUANG Si;DING Tiantian;YAN Chao;WANG Zisheng
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    By using the software of Airpak, unsteady air flow and heat transfer in a drying room used for containers are simulated with two different schemes of air supply. The transient numerical solutions are obtained for air flow within the drying room, including flow speed, pressure, temperature, mean age of air, etc.. The analysis focuses on temperature field distribution, temperature rise, and the mean age of air surrounding the container surface changing with heating time. Two air supply schemes are that scheme one with air inlets located on the ground under the container and scheme two with just air inlets raised into the container, the rest of factors remaining unchanged. Calculation results show that comparing with scheme one, in scheme two, the temperature field distribution is evener, temperature raises more quickly, and the mean age of air is smaller, especially in critical places where it is difficult to dry. It could be concluded from the results that scheme two is the scheme that should be selected for better drying quality, shorter drying time, and less energy consumption.
  • LI Shaohua;HUANG Hongwei;LI Can
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    An anti-lock braking system for a heavy vehicle was simulated based on ADAMS and Matlab/Simulink. A nonlinear heavy vehicle dynamic model was built in ADAMS/Car, including the front and the rear suspension systems, the vehicle body, the engine system, the steering system, the antiroll system, the brake system, and the tire dynamic model. The nonlinear characteristics of the tire, the bushing spring and the damper were considered so as to reveal the dynamic performance of the vehicle accurately. A fuzzy control Anti-lock Braking System(ABS) model based on the wheel slipping rate was built in Matlab/Simulink. Then the straight-line braking simulations were carried on three types of roads with high friction coefficient, low friction coefficient and split friction coefficient under different vehicle loads. In a joint simulation, the braking dynamic responses of the heavy vehicle were compared with the case of a general brake without ABS. It is shown that the ABS fuzzy control based on the slipping rate as designed in this paper performs very well for the heavy vehicle. The wheel slipping ratio could be maintained near the optimal slipping ratio, and each wheel is prevented from locking up. In addition, the braking distance, the braking time, and the braking stability are greatly improved.
  • LIU Jianjun;YU Xianbin;XIONG Huan;ZHANG Linzhi
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    The perforation, to a certain extent, can effectively reduce the formation fracture pressure to avoid cracked distortions and multiple fractures. And the perforation parameters are related with the borehole wall surrounding rock stress and the fracture pressure, thereby, the fracturing pressure capacity and the dynamic evolution of the perforation shaft wall surrounding rock stress field are important issues for the hydraulic fracturing operation, the wellbore stability, and the reservoir reconstruction. In this paper, firstly, using the finite element analysis software ABAQUS, a three-dimensional numerical model of the casing-cement ring-formation is established to study the fluid-structure coupling effects and the dynamic effects. A qualitative understanding of the borehole wall surrounding rock stress distribution and the hydraulic fracturing breakdown pressure is achieved and the optimal perforating parameters are obtained by the numerical simulation on the basis of the single variable theory for the perforation parameters, including the perforation density, the perforation length, and the perforation azimuth. The results provide some theoretical guidance for the fractured well perforating technology optimization design.
  • SU Haitao;YANG Jing;ZHANG Sen
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    This paper studies the vibration characteristics of the phononic crystal beam on elastic foundations, based on the Euler beam theory and the Winkler foundation model. The finite element method is used to obtain the band structures of phononic crystal Euler beams. The results reveal the influence of the foundation constraint on the bending vibration band gaps in the phononic crystal Euler beam. The computational results of the band structures of the phononic crystal Euler beam without foundation are compared with those on the elastic foundation. The significantly different band gaps of the model are shown.. The influences of different component ratioes of the phononic crystal Euler beam model are also studied, as well as the frequency ranges of the vibration band gaps.
  • MA Xia;WU Yanli;YU Hongqian
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    The paper studies the preparation of the fragrance microcapsule, of diameter in the range of 200-600nm and with the coefficient of dispersion less than 0.30, enjoying a long sustained-release effects, based on β-poly-malic acid (PMA) and chitosan (CS) as the wall materials. The Plackett-Burman design was adopted to select the most important nutrients and Box-Benhnken Design was used to identify the optimum concentrations of the key nutrients. The optimum conditions were determined: the chitosan concentration of 1.5g/L, the emulsification of 45min, the rotational speed of 600r/min, the reaction time of 60min, the poly (malic acid) concentration of 1.0g/L, the ratio of poly (malic acid) to chitosan of 1:2, the pH value of 6.0, the dropping speed of 7.5mL/h, and the core material amount of 1mL. In the SEM observation of the micro-spherical microcapsules, the particle size is 481.0nm, and the embedding ratio is 28.57% with a continuous long-term releasing effect.
  • BAO Yanyan;WU Di;YUN XingFu
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    Previous studies show that the celery extracts have the allelopathic effect on the Fusarium oxysporium f. sp. Cucumerinum with an inhibitory rate of 12.89%-84.83% and different fresh celery root and root soil extracts have different prohibitive allelopathic strengths against the cucumber wilt. With a steep decline in morbidity, however, the prohibitive allelopathic strengths are within 5.45%-46.95%. An interesting issue is the mechanism of the celery extract allelopathy, including the protective enzyme systems, the soluble substances and the active oxygen metabolism of the cucumber leaf, which were studied by researchers However, little attention was paid to the phenol and nitrogen metabolites in the cucumber leaf To study the mechanisms of the celery root soil extracts allelopathy on the Fusarium oxysporium f. sp. Cucumerinum, the changes in the phenol metabolites and the nitrogen metabolites were analyzed in "Jinchun 4"cucumber leaves treated with the extracts once its first leaf was 5cm wide, including the lignin, the tannin, the chlorogenic acid, the ferulic acid, the amino acid, the soluble protein, the ammonia, the nitrate and the nitrite. It is shown that the phenol metabolites in the cucumber leaves treated with the celery root soil extracts are significantly higher those without the treatment, the content of the nitrogen metabolites changes significantly, the contents of the Arg, the Pro, the soluble protein, and the ammonia are higher, but the contents of the Gly, the Val, the Met, the Ile, the Phe and the nitrate are lower. For different treatments, the most significant effects on the phenol metabolites and the nitrogen metabolites are caused by the acetone extracts, followed by the ethanol extracts and the distilled water extracts.
  • YE Xiaorong;SHAO Qing
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    The mobile internet in China is under very rapid development, but the print advertisement encounters some difficulties to enter the mobile advertising market, lack of desirable effects. This paper proposes a new solution. Based on the Android platform, a mobile advertising system is designed, which takes advantage of technologies such as the augmented reality and the location based services, with the adoption of the ARToolKit, Hadoop, Blender, min3D and other open source software modularization designs. This system consists of two parts: the mobile client side and the server side. In the first step, the mobile client is responsible to recognize the two-dimensional codes from the print advertisement, and to locate the coordinates of the current location of the phone. Then these data are sent to the server. In the second step, the server using the scope of the search algorithm obtains the corresponding 3D virtual image advertisement file by retrieving the map database and the virtual image file library. After the server sends the advertisement file back to the phone, the mobile client is able to display the 3D virtual image advertising finally. This system makes the advertisement more effective and targeted.
  • Reviews
  • TIE Shengnian;HOU Siyi;WANG Chang'an;WANG Tao
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    With the rapidly increasing demand of the silicon wafer, due to the use of the cutting fluid in the cutting process, a large amount of cutting waste liquid will be produced. This paper reviews the researches of the production and cutting techniques, the online recycling process and the offline recycling process of the silicon carbide cutting waste in the new energy resource silicon industry, with focuses on the physical and chemical methods in the offline recycling process used to recycle the cutting waste liquid. It is shown that the comprehensive recovery of the silicon carbide, the polyethylene glycol and the silicon, instead of only recycling the silicon carbide, is the trend. The physical methods in the offline process have advantages of low energy consumption, simple process, low-cost equipment and easiness for industrialization. Among the physical methods, the separation method of the electing effective collector and using the forth floatation technology is simple to operate and enjoys a high separation efficiency, and it becomes the key of the current research. The chemical methods depend on the transformation of the raw materials to produce the new product and to recycle the silicon carbide at the same time. The recovered materials have a high purity. This method has potential applications and deserves further researches.