08 July 2011, Volume 29 Issue 19
    

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  • BI Yinli;YU Miao;CAO Nan;WANG Zhen;HUANG Bo
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    Phosphorus is one of essential elements of a large number of nutrients for the plant growth. The soil contains a lot of insoluble phosphate. When available phosphorus is reduced, the plant growth and development would be affected. Solubilizing bacteria could change the insoluble phosphate into soluble phosphorus in order to increase available phosphorus in the soil. Through the corn pot experiment, the different strains named Glomus aggregatum(G.a) and phosphate-solubilizing bacteria isolated from Coal fly Ash (CA), their join effects on the release of insoluble phosphate contained by the land, and the effect on plant growth are compared. The results show that the join effect of arbuscular mycorrhizal fungi and phosphate-solubilizing bacteria significantly increases the plants' aboveground and underground biomass; they efficiently release the insoluble phosphate from adding sand to increase available phosphorus content in the soil; pH is increased from acid to neutral; they increase the activity of acid phosphatase, convert organic nutrients into inorganic one, and make them easily absorb by plants; mycorrhizal inoculation significantly increases root colonization and hyphal density, expands root absorption area, and improves the environment of the rhizosphere soil in order to achieve the purpose for promoting plant growth. Microbial reclamation conducted by arbuscular mycorrhizal and phosphate-solubilizing bacteria is of great significance to the ecological restoration of desertified barren land.
  • ZHAO Hua;DUAN Shenglin;HE Congfen;WANG Ling;SONG Jie;WANG Xue;CHEN Zhirong
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    Soybean molasses is the by-product of the production of concentrated proteins in soybeans. It is a kind of brown sticky pulp thing after the concentration of extract liquor by the ethanol of defatted soybean meal. Soybean molasses contains a variety of functional components. It mainly includes soybean oligosaccharides, soybean isoflavone, and other physiologically active components, which have many beneficial effects on the human health. By using monosaccharides and polysaccharides with the method of fermentation, the concentration of functional polysaccharides is improved and the purpose of purifying glycogen is achieved. One strain of yeast, that is, Saccharomyces cerevisiae C that has the function of high consumption to sucrose, and high retention rate to stachyose and raffinose is screened from four stains of yeast and one strain of lactobacillus. The optimal condition for the fermentation of soybean molasses is initial molasses sugar concentration of 9%, initial pH value of 6.5, inoculation amount of 3% and fermentation at 30℃ for 24h. The retention rates in hydrolysates of soybean molasses are 0% for sucrose, 60.90% for functional oligosaccharide, and 24.46% for glucose and fructose. And repeat stability reaches at 95% under the optimal fermentation condition.
  • TIE Shengnian;LI Xing
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    The surface modification of SiC powder with KH-550 aminoorganosilanes was carried out and the optimum process parameters of modification were pointed out by using single factor experiments and orthogonal experiments. The optimum reaction temperature is 90℃, the optimum reaction time is 4h, and the optimum KH-550 concentration is 1.5g. Modified powders are characterized by using scanning electron microscopy, X-ray diffraction, infrared spectroscopy, and laser particle size analyzer. The effect of surface modification on the dispersion stabilization of SiC slurry is also analyzed. The results show that the SiC powder treated by aminoorganosilanes does not change the phase structure of original SiC; it only changes the colloidal properties in water. d0.5 decreases slightly and particle size distribution narrows down. SEM shows that powder agglomeration is reduced and dispersion property is improved for SiC powder. Comparing with the original SiC powder, the surface characteristics of modified SiC powder occur a great change and Zeta potential increases from 17.58mV to 41mV(with pH=3.78). The dispersion stabilization of SiC slurry is remarkably increased.
  • ZHANG Jiquan;ZOU Taohong;LU Xingchang;YI Kunpeng;TONG Zhijun;LIU Xingpeng
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    The land use is a basic issue in the relationship between human and land, and the most direct activity of human with respect to nature is related with the manner of land use; the different types of land use will undoubtedly have different impact on the land eco-system, such as the reduction of the soil organic content, the change of vegetation coverage. In this paper, using the Landsat TM image and the related statistical data, based on the GIS technology and the fuzzy comprehensive evaluation method, the health analysis is made for each land eco-system under different land use types in Badaojiang area in Baishan city. In view of the ecological benefits, the social benefits and the economic benefits of the land eco-system, the states of health stations of the land eco-system are divided into five grades: best, fairly good, general, bad, and worst. And the results show that, the health state of the forest system is the best, then comes the grassland system, the health state of the cultivated land is general, and the health state of the building land is the worst. These results can provide a reference for the future land use in the Badaojiang area, to avoid improper measures in the land use process, for the most efficient land use, and the sustainable use of land.
  • LIU Zhaomiao;ZHANG Chengyin
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    Due to its good carrying performance, low frictional resistance, high precision and stability, the hydrostatic support system becomes the core component in high-precision CNC machine tools. The study of the oil cavity's carrying stability is important in order to improve the precision of machine tools. In this paper, the flow and the bearing carrying capacity of the cycloidal hydrostatic oil cavity in a hydrostatic turntable system is numerically studied for rotating speed ranging from 0 to 5m/s of the turntable and under varied boundary conditions. The results show that the static bearing capacities of the oil cavity are reduced with the increase of oil film thickness. By increasing the lubricant viscosity, the effect of vortex will be weakened and the stability of the oil cavity will be enhanced. With the increase of the oil cavity's depth and the inlet radius, the vortex effect will be enhanced and the stability of the oil cavity reduced. The carrying capacity of the oil cavity diminishes with the increase of the oil film thickness. The oil cavity pressure due to the turntable's rotation is unevenly distributed and increases along the direction of the turntable's motion. With the increase of the turntable speed, the location and the size of the vortex vary in the oil cavity flow field and the strength of the vortex nearby the entrance is gradually weakened and the vortex goes away from the entry. The distribution of the pressure is determined by the location of the vortex. When the vortex is near the wall, the wall pressure will increase at that location. Otherwise, the wall pressure will decrease.
  • ZHOU Yunshan;ZHAO Bin
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    Aiming at the limitations of general ratio controller for Continuously Variable Transmission (CVT), an improved PID control algorithm, which has the engineering value, is presented based on the CVT ratio control strategy, an improved PID controller is designed in the Matlab environment. Moreover, considering that the single simulation software is unable to precisely express model parameters, the vehicle model is developed in Cruise, and co-simulation with Simulink model in term of API is conducted. The simulation results show that the designed controller and joint simulation are feasible, the improved speed ratio controller could well follow the target speed ratio and has the good dynamic response and high control accuracy in a steady state, the results of simulation are well consist with the actual status of the prototype cat, the correctness of the theoretical analysis is verified, and also reflected the CVT's technological superiority in terms of vehicle fuel economy and power.
  • GUO Hongbin;CHEN Jianhong;YANG Shan;LIU Lang
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    A distribution model with two tobacco transfer stations is used to improve the tobacco distribution with the conventional cigarette transportation, and the maximal covering model is used to locate the transfer stations, then the transportation optimal model with a trapezoidal fuzzy parameter is proposed. Combined with the constraints of the suppliers' supply capacity and capability needs of demand points as fuzzy parameters, a new method of linear programming based on the concept of constraint satisfactory degree is proposed. In order to solve the problem of the transport planning model with fuzzy parameters, the interval-valued mean is used to transform the uncertain model into an interval number linear programming model, which is finally transformed into a deterministic linear programming model. With this method, the decision maker can obtain a corresponding satisfactory solution according to different conditions, so the decision process becomes more flexible and more adaptable to real situations. By adopting this method, the transportation costs of tobacco companies in this city are greatly reduced, saving 5.37% of the direct distribution model cost.
  • ZHANG Xiaoliang;LI Di;SUN Junshu;YU Rongze;GONG Ruxiang;LIANG Tao
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    A new productivity analysis method for the fractured well in low-permeability reservoir is derived on the basis of reservoir engineering and numerical calculation. The starting pressure gradient, reservoir pressure sensitivity, and the conductivity attenuation of the artificial fractures are all taken into account in the well productivity analysis. A calculation instance was performed and the comprehensive analysis of the predicted result was provided to study the effect of different factors on the well productivity. The result shows that with the decrease of bottom-hole pressure, pseudo-startup pressure gradient, the deformation coefficient, and the increase of oil production in the early stage, the production declines rapidly. At the same time, with the increase of the artificial fracture conductivity attenuation coefficient, the oil production in the early stage also increases and then declines rapidly as well. At last, the productivity analysis method was applied to the field applications. There is a quite good agreement between the predicted result and the actual production data, the fact has verified the correctness of production analysis method.
  • WU Fengliang
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    In order to make sensibility calculation for a complicated mine ventilation net work easier, the concept of sensibility and stability of a ventilation network were analyzed. An analytic formula to determine the sensibility was put forward. Furthermore, Microsoft Visual C++ software was employed to generate a sensibility calculation program. By introducing mutability coefficient of branches, the calculation method of stability based on the sensibility was optimized. A case was adopted to analyze the attenuation rule of sensibility. And the conclusion is that the more the ventilation constructs are, the more stable the ventilation system is, and it obviously disagrees with the experiences. Aiming at this contradict conclusion, it is pointed out that the definitions of stability in a ventilation system are different while based on the ventilation constructs or on the sensibility. The ventilation constructs are always resulted in the sudden change of air resistance, however, the sensibility always aims at a little change of air resistance. It is also pointed out that ventilation constructs play an even more important role in the ventilation stability. The research result is propitious to optimal choice of projects during the coal mine's ventilation design and reformation.
  • LI Wei;JI Xiaobin;CONG Jing;WU Xiaoke
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    Ovarian cell Insulin Resistance (IR) and abnormal homogenesis is one of the characteristics of Polycystic Ovary Syndrome (PCOS) and could be remedied by the insulin sensitive agent. To investigate herbal medicine as insulin sensitive agents to improve IR ovarian granulosa cell in vitro and clarify the mechanism of herbal medicine on IR, glycyrrhetic acid and silibinin were used to treat dexamethasone (DEX) induced IR porcine ovary granulosa cells. After DEX treatment, the medium testosterone level increased, while the CYP17 mRNA expression increased and the AMP-activated protein kinase activity (AMPK), which is a protein that switches on ATP-producing catabolic pathways and switches off ATP-consuming anabolic processes based on energy status, mRNA expression decreased in vitro IR porcine ovarian theca cell. The results also show that compared to dexamethasone induced IR group, by adding glycyrrhetic acid and silibinin, testosterone production is reduced and mRNA expression of AMPK is increased. In summary, glycyrrhetic acid and silibinin significantly reverse hyperandorgen (testosterone) status and improve the sensitivity of energy balance by promoting the expression of AMPK. Chinese medicine glycyrrhetic acid and silibinin could reduce the hyperandrogenism of in vitro IR granulosa cell via increasing AMPK mRNA expression.
  • GUO Yana
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    On August 10, 2006, the super typhoon Saomai landed in Wenzhou, Zhejiang Province. It is the strongest typhoon landed in Chinese inland since 1949. Saomai seriously affected the coastal areas of eastern China, and caused 25 billion US dollars in losses. Saomai caused serious damages to the Zhejiang, Fujiang, Jiangxi, Hunan Province, respectively. Saomai characters in term of the path and the strength are analyzed in order to give a reference to the analysis and prediction of the typhoon in the future. The results show that there is a quite close relationship between the moving path of the typhoon and the environmental wind field around the typhoon. Therefore, environmental wind field around typhoon must be considered while predicting the path of typhoon. The Saomai is reinforced by small vertical wind shear and strong upper divergence. The strong upper divergence is in favor of production of surface convergence, and then enhances the strength of the typhoon. Among the factors for enhancing the typhoon, the change in its scale also needs to be considered. The typhoon horizontal scale shrinking makes the typhoon energy concentrate, and then enhance the intensity of the typhoon. The emergence of negative divergence field at upper air, the vertical wind shear, landfall, and other factors are the main reasons for its slowing down.
  • Reviews
  • SONG Song;WANG Xuetian;DENG Jiahao
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    Millimeter wave has a nice air propagation property and could provide a moderate angular resolution. On the basis of the discussion involving the theory and characteristic of Passive Millimeter Wave (PMMW) image, the current advances of foreign countries in this domain including the devices, systems, and the signal processing methods are introduced. Then, domestic research work is proposed, and furthermore the developing trend and applications of PMMW image are also detailed.