Table of Content

28 May 2012, Volume 46 Issue 05 Previous Issue    Next Issue

Engergy and Power Engineering

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Experimental Investigation on Humid Air Diffustion Combustion in a Multihole Nozzle Swirl Burner GE Bing, ZANG Shu-Sheng, GUO Pei-Qing 2012, 46 (05):  661-665.  Abstract ( 3342 )   Save Experiments were performed to investigate the flow structures of humid air combustion flame in a multihole nozzle swirl burner. The experiments show that with steam addition, the flame becomes dark, and the flame dimensions grow; the distances between vortexes of recirculation zone and nozzle reduce; the peaks of radial mean velocity, radial rms velocity and Reynolds shear stress decrease; the maximum mean turbulent kinetic energy decreases, and the biggest reversing velocity on nozzle centerline reduces; the width of recirculation zone and the distance between centerline biggest reversing velocity and nozzle is lower; the expansion angle of swirling jet reduces；the axial nonuniform coefficient of outlet increases. References | Related Articles | Metrics

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Experimental Study of NOx Storage/Reduction (NSR) Using DME as Reducer ZHOU Xiang-Man, CHEN Xiao-Ling, WU Jiao, WU Min-Chao, QIN Ping, ZHANG Wu-Gao 2012, 46 (05):  666-670.  Abstract ( 3469 )   Save  Using Pt/Co-BaO/γ- Al2O3 as the catalyst, dimethyl ether (DME) as the reductant, this paper investigated the NOx storage-reduction (NSR) percormance and the influence of the reduction time and temperature on the DME-NSR. The result indicates that the NOx conversion ratio for NOx can be kept between 60%~70%. Then the influence of DME on the thermal stability of the stored NOx over the NSR catalyst was investigated by using the temperature programmed desorption (TPD) and DME temperature programmed surface reaction (DME-TPSR). The result indicates that DME can promote the decomposition of the nitrate over the catalyst, and then react with the decomposed NOx.   References | Related Articles | Metrics

Energy and Power Engineering

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Migration Characteristic of Spherical Nanoparticles from Liquid to Vapor Phase during Refrigerant/Nanolubricant Mixture Boiling DING Guo-Liang-1, PENG Hao-2, HU Hai-Tao-1, ZHUANG Da-Wei-1 2012, 46 (05):  671-676.  Abstract ( 2982 )   Save In order to evaluate the heat transfer characteristics of nanorefrigerant and the cycle behavior of nanoparticles in the refrigeration system, the migration of nanoparticles during pool boiling was investigated experimentally. Weigh method is used in the present study. The research focuses on the influence of nanoparticle type and size, refrigerant type, mass fraction of lubricating oil, heat flux and initial liquidlevel height on the migration of nanoparticles during pool boiling. The experimental results show that the migration ratio of nanoparticles during the pool boiling of refrigerantbased nanofluid increases with the decrease of nanoparticle density, nanoparticle size, dynamic viscosity of refrigerant, mass fraction of lubricating oil or heat flux; while increases with the increase of liquidphase density of refrigerant or initial liquidlevel height. References | Related Articles | Metrics

Engergy and Power Engineering

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Experimental Study on Automobile Exhaust Thermoelectric Generator in Series QUAN Rui-a, TANG Xin-Feng-a, QUAN Shu-Hai-b, c , HUANG Liang-b 2012, 46 (05):  677-682.  Abstract ( 3732 )   Save To utilize the exhaust heat of automobile engine, a kind of fourlayer automobile exhaust thermoelectric generator (AETEG) in series which is composed of Bi2Te3 based thermoelectric modules of low temperature was designed, its output performance was tested with bench experiments and the influence factors were analyzed. The experimental results validate that its maximum power recovered is almost 60W when the maximum hot side temperature of a certain thermoelectric module approaches its maximum enduring temperature, only with the indirect cooling manner in this system the cold side temperature of AETEG can hardly be cut down evidently so that temperature difference between its hot side and cold side is not evident, the output performance of the intermediate two layers in series is much superior to the ones of the other two layers on the same occasions, the overall output performance of AETEG can be improved for the heat capacity and surface temperature of heat exchanger can be increased evidently when decreasing its dimensions appropriately. References | Related Articles | Metrics

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Influence by Heat Conductivity of Battery Framework to Thermal Process of Underwater Vehicle’s Battery Compartment WANG Yan-Feng, HU Yu-Li 2012, 46 (05):  683-687.  Abstract ( 2539 )   Save Thermal process inside battery compartment of underwater vehicle was theoretically analyzed and experimentally measured when batteries are discharging under some working condition. Otherwise, temperaturetime curves and temperature contours inside battery compartment were simulated by FLUENT software when heat conductivity of battery framework is different. It is indicated that when the heat conductivity of battery framework is higher, the maximum temperature inside compartment is lower, meanwhile, using aluminum framework can lower the maximum temperature to 64 °C, which can meet the temperature requirement (≤70 °C). References | Related Articles | Metrics

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Variation on Multicylinder Gasoline HCCI /SI Engine Based on Optimized Kinetic Process Technology ZHANG Xu-Zhou-1, ZHENG Hua-Hang-1, LI Zhong-Zhao-1, SHEN Yi-Tao-2, 吕Xing-Cai-1 , FANG Jun-Hua-1, HUANG Zhen-1 2012, 46 (05):  688-694.  Abstract ( 2801 )   Save Stable homogeneous charge compression ignition (HCCI) combustion on a commercial gasoline engine was realized through the optimized kinetic process technology. Statistical analysis method was adopted to analyze the spark ignition (SI)HCCI switching process at different load point. And then the same method was used to analyze cycletocycle and cylindertocylinder variation characteristics for these two modes under the same load. Finally, the restrict conditions and solutions for HCCI load expansion were discussed. The results show that, for the switching process at low engine speed 1 400 r/min, properly increasing load can make switching process more smoothly; at the same load, each combustion parameter variation in HCCI mode is remarkably less than that of parameters in SI mode, the cycletocycle variation of indicated mean effective pressure is less than 2.5% and the cylindertocylinder variation is less than 3.0%. The statistics also show that each cylindertocylinder combustion parameter has regular difference; this trouble can be solved through the rearrangement of intake manifold and coolant circulation. Meanwhile, in order to expand the HCCI load, decreasing the inlet air temperature and exhaust gas recirculation strategies should be used to retard the beginning of combustion and slow the rate of heat release. References | Related Articles | Metrics

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Effects of Spark Assisted HCCI on Combustion and Emissions  in Multicylinder Gasoline Engine ZHENG Hua-Hang-1, ZHANG Xu-Zhou-1, LI Zhong-Zhao-1, SHEN Yi-Tao-2, ZHANG Jian-Yong-2, FANG Jun-Hua-1, 吕Xing-Cai-1 , HUANG Zhen-1 2012, 46 (05):  695-700.  Abstract ( 3672 )   Save Applying optimized kinetic process technology the waste thermal energy in the coolant and exhaust gases for intake air heating was used to realize HCCI combustion in a multicylinder gasoline engine. The effects of spark assisted HCCI on combustion and emissions were investigated. The results show that utilization of spark assisted HCCI is found to increase indicated mean effective pressure (IMEP), pmax, (dp/dθ)max and reduce cyclebycycle variation so as to improve the stability of HCCI combustion. Spark assisted HCCI can achieve a twostage combustion. When increasing the spark advance angle, the heat release rate peak value will increase. The introduction of spark significantly advances the combustion to top dead center (TDC) and lowers the NOx and HC emissions. References | Related Articles | Metrics

Mechanical instrumentation engineering

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Bayesian Networks Modeling Based on Small Samples for VariationSource Diagnosis LIU Yin-Hua, JIN Sun 2012, 46 (05):  701-705.  Abstract ( 3254 )   Save Based on the small samples collected in the assembly process, a new approach based on Bayesian networks was proposed for the variationsource diagnsosis. The conditional independence testing algorithm was proposed to obtain the structure of Bayesian networks. After the prior conditonal probabilities are calculated based on the mapping of the variation simulation model, posterior conditonal probabilities are updated by incorporating the small sample data. The results of the body side case show the method is effective and acurate for fixture fault diangosis. References | Related Articles | Metrics

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Manufacturing Quality Evaluation for the Complex Curved Surface of HighSpeed Train Driver Room WU Tao-Sheng-1, LI Zhi-Min-1, FENG Xiao-Zhong-2, YANG Yan-Qun-2, WANG Hua-1 2012, 46 (05):  706-711.  Abstract ( 2709 )   Save The evaluation for complex curved surface of highspeed train driver room was investigated from three aspects including dimension precision，surface profile and surface smoothness. On the basis of dimension variation calculating with the algorithm of subdivision approach and surface smoothness analyzing with the map of Gauss curvature and reflection line，a new method for the evaluation of profile deformation rule and microscopic geometrical characteristics was brought forward, which uses normal vector to analyze the curved surface. The comprehensive evaluation model was performed based on quantified results of surface smoothness with fuzzy math using the method of TOPSIS. The test on the application in actual manufacturing shows that the new method and model of evaluation for complex curved surface are effectual．   References | Related Articles | Metrics

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Integrated Model of Preventive Maintenance Policy and EPQ for Reconfigurable Manufacturing System WANG Gui-Na, PAN ErShun 2012, 46 (05):  712-716.  Abstract ( 3064 )   Save An integrated economical production quantity (EPQ) model of a typical parallelserial reconfigurable manufacturing system producing a single product was proposed, which is generalized by integrating maintenance and configuration policy with the EPQ model. Periodic preventive maintenance policy with minimal repair at failure is considered, and when the production rates change and system reliability reaches predesigned threshold, configuration action will occur. Based on these policies, a profit model was formulated including set up cost, holding cost, minimal maintenance cost, preventive maintenance cost and production cost. The objective is to maximize profit with appropriate EPQ by obtaining the optimal PM period and system reliability threshold. Finally, a numerical example was given to show that the model is reasonable. References | Related Articles | Metrics

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Deviation of Light Spot in Rotationally Symmetric Triangulation Sensor ZHANG Hai-Bo, TAO Wei, YANG Jin-Feng, ZHAO Hui 2012, 46 (05):  717-721.  Abstract ( 2665 )   Save To illustrate the effect of the deviation of the spot in a rotational symmetric triangulation sensor, the model of the relation between the radius of the ring in the image and the deviation of the spot was built. Based on the model, the average radius of the ring with different deviations of the spot was estimated, and the change of the ray in direction was also discussed. The experimental results agree well with the theoretical results. Therefore, the model can be used as a useful tool for the design, optimization and manufacture of the sensor.   References | Related Articles | Metrics

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Numerical Analysis of Gas Thermal Viscosity Effect on Performance of a Spiral-Groove Gas Face Seal XU Jing-a, PENG Xu-Dong-a, b , BAI Shao-Xian-a, b , MENG Xiang-Kai-a, b , LI Ji-Yun-a, b 2012, 46 (05):  722-728.  Abstract ( 4201 )   Save The modified Reynolds equation was presented based on the theories of both gas polytrophic process and gas lubrication so as to study the thermal viscosity effect of gas on seal performance of a spiralgrooved dry gas seal (SDGS). The finite element method was used to solve the governing equations and analyze the influence of thermalviscosity on the dry gas seal sealing performance. The results show that due to the high polytrophic exponent, the greater the values of gas film pressure, gas film temperature and gas film viscosity, the stronger the loading capacity of gas film. When an SDGS is operating at high speed or at medial or high pressures of sealed gas, the thermal viscosity effect should be considered to get more accurate simulation values of seal performance. The variations of seal performance with film thickness would not be affected by thermalviscosity effect  when film thickness is greater than two micrometer. Key words： References | Related Articles | Metrics

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Similarity Relationship of Fretting Amplitudes Between Scaled-Model Wheel-Set and Prototype Wheel-Set ZENG Fei-1, 2 , CHEN Guang-Xiong-1, ZHOU Zhong-Rong-1 2012, 46 (05):  729-733.  Abstract ( 3684 )   Save  In order to provide a reference for designing model tests and analyze the results of the model tests, the similarity relationship of fretting amplitudes of the interference fitting surfaces between the prototype wheel-set and its geometrically similar scaled-model one was deduced based on the dimensional analysis theory. The material of the prototype wheelset was the same as that of the scaled-model one. The results show that when the size of the model wheelset, the interference value and the axle load are 1/n, 1/n and 1/n2 of those of the prototype one respectively, the fretting amplitudes of the interference fitting surfaces of the model wheelset is 1/n of that of the prototype one. Finally, the fretting amplitudes of scaling 1∶2, 1∶5, and 1∶10 model wheelsets were compared with those of the prototype one from ANSYS analyses, respectively, which verifies the correctness of the similarity relationship. References | Related Articles | Metrics

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3D-PIV Measurements of Stall in DoubleBlade Centrifugal Pump LIU Hou-Lin, YANG Dong-Sheng, TAN Ming-Gao, WANG Kai, ZHUANG Su-Guo, DU Hui 2012, 46 (05):  734-739.  Abstract ( 4089 )   Save In order to study the stall in centrifugal pumps, the internal flow field in three sections of a doubleblade centrifugal pump was measured by 3D particle image velocimetry technique (PIV) at four flow rates. With the decrease of the flow rate, flow separation occurs at the pressure side of the impeller blade firstly, which results in a vortex near the pressure side of the blade. When the flow decreases more, the vortex blocks the channel and flow field gets worse, which causes the stall phenomenon. Under the optimum condition, the flow pattern in the impeller is best. At 0.8Qopt (the flow rate at the optimum condition), flow separation is observed in the middle section. At 0.5Qopt, the stall occurs in the middle section due to the extending of flow separation. Before reducing the flow rate to 0.2Qopt, the stall occurs in the section near the shroud. But there is no vortex found in the section near the hub. The axial velocity field in the passage shows an asymmetrical distribution, and the axial velocity decreases from the entrance to the exit of the passage. Also, it decreases from suction side to pressure side of the blade. And the negative axial velocity area near the pressure surface extends with the development of stall. References | Related Articles | Metrics

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Sphere Generation Grinding Based Spherical Surface Marks Analysis WANG Yu-Jue, XU Li-Ming, LI Dong-Dong, WANG Jian-Lou, SHI Lun, HU De-Jin 2012, 46 (05):  740-745.  Abstract ( 3177 )   Save  A grain trajectory model was developed based on spatial motion analysis. The relationships between grinding marks and various process parameters were discussed and the concept of grinding marks density was put forward in order to evaluate the marks. The influence of grinding marks on the lubricating and sealing performance was analyzed, and the favorable marks together with the parameter control methods were discussed. Optimizing parameters were presented based on the analysis. The model was validated by the experiments. The results show that the shape and distribution of grinding marks are determined by both the process parameters and structural parameters. For higher surface quality and favorable grinding marks which benefit lubricating and sealing, the parameters and system parameters need to be reasonably selected. References | Related Articles | Metrics

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Optimal Locator Layout Design for Compliant Fixture System MA Jie-1, WANG Yu-2, ZHU Xiang-Yang-1 2012, 46 (05):  746-749.  Abstract ( 3329 )   Save For the problem of optimal fixture layout design in discrete point set domain, this paper proposed a topology optimization method. A penalized spring contact model was presented. The spring densities of the candidate contact points were introduced as a set of design variables. The objective is to minimize the deformation of the workpiecefixture system. The implementation of the algorithm and numerical examples were also presented. The results show the effectiveness of the proposed method for both 2-D and 3-D cases. References | Related Articles | Metrics

Aeronautics & Astronautics

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On-Orbit External Heat Flux Calculation of Spacecraft Based on Reverse Monte Carlo Method PAN Qing-1, WANG Ping-Yang-1, BAO Yi-Ying-2, LI Peng-2 2012, 46 (05):  750-755.  Abstract ( 3974 )   Save In order to calculate the orbit external heat flux in consideration of seasonal and latitudinal variations in earth albedo and emission, the reverse Monte Carlo method model was established which can be used in any kind of earth orbit and aircraft attitude. The model also can take surface covering and multiple reflection into account conveniently. The aircraft attitude was determined in term of the given orbit parameters at any time by continuous coordinate transformation method. The results gained on the constant earth radiation characteristics condition were compared with the results gained by commercial software to verify the accuracy of the model. Then, the orbit external heat flux was computed on varying earth radiation characteristics condition. The results display that the model is reliable to aircraft attitude control and external heat flux calculation. Earth infrared emission and earth albedo radiation vary considerably with latitude. The biggest relative difference of earth infrared emission of all check moments is -21.31%, while the biggest relative difference of the earth albedo radiation is 80.05%, both at 57 degree south latitude. The surface covering and multiple reflection effect are obvious, leading to the earth albedo radiation of the surface with an antenna change from 19.2 W/m2 to 39.5 W/m2 as an example. References | Related Articles | Metrics

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Study on DIMA Integrated Techniques for Communication Navigation Identification System of Attack Helicopter XU Li-1, PANG Rui-Fan-2, 3 , ZHANG Yi-1, GUAN Xin-Ping-4 2012, 46 (05):  756-761.  Abstract ( 5408 )   Save The communicationnavigationidentification (CNI) system of attack helicopter represented by AH64D “Apache” was introduced. The distributed integrated modular avionics (DIMA) architecture based on time triggered mechanism was analyzed. An architecture of CNI system based on DIMA architecture and common object request broker architecture (CORBA) logical software bus technology was built. The results show that this architecture achieves to support high integration of communication resources which are close to RF frontend by building distributed system architecture and high fault tolerance communication network, adapts to natural cooling condition for attack helicopter, and meets the maintenance requirements of rapid fault propagation. References | Related Articles | Metrics

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Study on Modular Integrated Techniques for Communication Navigation Identification System of Utility Helicopter ZHOU Cheng-1, PANG Rui-Fan-2, 3 , WEI Bao-Guo-1, GUAN Xin-Ping-4 2012, 46 (05):  762-767.  Abstract ( 4151 )   Save The technical characteristics of communicationnavigationidentification (CNI) system of utility helicopter represented by SH60K and UH60Q were introduced. The drawbacks of federal avionics architecture in resource integration and information sharing were analyzed. An integrated modular architecture of CNI system based on integrated modular avionics architecture and hardware abstract layer technology was proposed. The results show that it supports function’s scalability, expansibility and reconfigurability, and meets the demand of utility helicopter for carrying out various missions. Key words： helicopter; communicationnavigationidentification (CNI) system; integrated modular avionics (IMA); software communication architecture (SCA) References | Related Articles | Metrics

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Buckling Optimization of Composite Laminate Using Modified Ant Colony Optimization LI Zhen, CHEN Xiu-Hua, WANG Hai 2012, 46 (05):  768-773.  Abstract ( 3629 )   Save Due to simple coding and strong dependence of global best value in the iterations of traditional algorithm, ants’ move method and pheromone updating strategy are modified on ant colony optimization (ACO). It was proposed to optimize the buckling design of composite plates, for the application of ACO is limited and the result is largely dependent on the global best value. After modification, the drawback of ACO is avoided and new iteration procedure is adopted in the new algorithm for higher efficiency. Examples of minimum thickness and stacking sequence optimization problems were used to demonstrate its validation and versatility. The results show that after modification the convergence process is quicker and the approach is found to give high accuracy, also the optimization results is the same as genetic algorithm (GA). References | Related Articles | Metrics

Environmental Science

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Heterotrophic Nitrification Capability and its Enzyme Activity of Alcaligenes faecalis strain NR AN Qiang-1, ZHAO Bin-1, HE Yi-Liang-2 2012, 46 (05):  774-779.  Abstract ( 4399 )   Save A heterotrophic nitrifying bacterium, Alcaligenes faecalis strain NR, was isolated from a membrane bioreactor. Citrate and ammonium were used as the sole carbon and nitrogen sources respectively to investigate nitrification characteristics of the new isolate. Under the aerobic condition of 30 °C and 120 r/min, the removal rates of NH+4N are 94.8%, 93.5% and 94.5% respectively when the initial concentrations are 20, 40 and 60 mg/L. And strain NR shows nitrification capability of producing nitrite and nitrate. To further understand the heterotrophic nitrification, enzyme assay was conducted. Sonication was used to obtain the key enzymes of AMO and HAO during nitrification process. Based on the singlefactor and orthogonal experimental results, the optimal ultrasonic conditions are: cell OD600 1.876, total working time 600 s, work/interval time 4, 6 s and power 300 W. The AMO and HAO enzyme activities under aerobic conditions are 0.011 U/mg protein and 0.016 U/mg protein respectively. References | Related Articles | Metrics

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Lytic Effect of Environmental Factors on Algae-lysing Bacteria Strain S7 by Fluorescence Spectroscopy WANG Jin-Xia, LUO Gu-Yuan, XU Xiao-Yi, YE Jiang-Yu 2012, 46 (05):  780-784.  Abstract ( 3038 )   Save Anabaena flos-aquae were scanned in vivo by fluorescence spectrum scanning to acquire characteristic fluorescence wavelength of phycocyanin and build a linear relationship between Anabaena flosaquae biomass and the phycocyanin characteristic fluorescence intensity. With the change of cyanobacteria growth conditions, the lytic effects of varying environmental factors (temperature, illumination and pH) to the algaelysing bacterial strain S7 were studied. The results show that utilizing fluorescence spectrum for detecting the phycocyanin fluorescence intensity and reflecting anabaena flosaquae biomass are simple, fast, accurate and feasible. Environmental factors affect the lytic effect of algaelysing bacterial strain S7. Levels of lytic effects are 30 °C>35 °C>40 °C>25 °C, dark＞light cycle＞full light, pH 5 >pH 10>pH 6>pH 9>pH 8>pH 7. For utilizing algicidal bacteria to control water bloom, exploring optimal environmental conditions for restraining the growth of those bacteria is of practical significance. Key words： References | Related Articles | Metrics

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State Prediction of Algae Reproduction Based on PCA-Fuzzy BP Method ZHANG Ying-1, LI Cai-Juan-1, SHAO Hui-He-2 2012, 46 (05):  785-789.  Abstract ( 2595 )   Save Principal component analysis (PCA) method combined with fuzzy back propagation (BP) network, called as PCA-fuzzy BP method, was proposed to predict the state of algae reproduction, and the prediction model of chlorophyll-a concentration was established. PCA method  was used to preprocess various acquisition data, it reduces the dimensionality of the input data of the system. The physicalchemical factors produced by PCA processing can be regarded as the input variables of the fuzzy BP network, the concentration of chlorophylla can be regarded as the output of fuzzy BP network, and the state prediction model of algae reproduction can be obtained by learning and training for this network. The experimental result indicates that PCA method reduces the correlation for the factors of input sample data, also reduces the dimension of the model system, accelerates the speed of modelling convergence for fuzzy BP network. The PCA-fuzzy BP algorithm has a faster speed of calculation and more accuracy of prediction than the typical BP network. This kind of model can give a better state prediction for algae reproduction. References | Related Articles | Metrics

Electrotechnology

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Thermal Analysis of Solar Panels in Orbit under Different Operating Conditions HUANG Hou-Xue, LIU Zhen-Yu, CHEN Ya-Qi, WU Hui-Ying 2012, 46 (05):  790-795.  Abstract ( 4141 )   Save  To investigate temperature distributions of solar panels in orbit under two operating conditions (full and half load), a thermal model was established by FEM analysis software I-DEAS TMG. The substrate of solar panels, which is composed of several composite materials, could be treated as an orthotropic plate, and the equivalent thermal resistance method is employed to derive the equivalent thermal conductivity of solar panels. The simulation results indicate that the temperatures of solar panels change periodically after five circles around the earth, and the range of temperatures under half load operating condition is wider than that under full load operating condition. Additionally, both the temperature difference through the thickness of solar panels and its first time derivative are highest when solar panels enter the eclipse, and these two values of half load operating condition are higher compared with those of full load operating condition. References | Related Articles | Metrics

Bilogical Science

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Correlation with Pellet Shape, Metabolic Profiling and Anticancer Activity of Endophyte FSN002 ZHANG Xing-Xing, YU Xiang-Li, MIAO Zhi-Qi 2012, 46 (05):  796-802.  Abstract ( 3190 )   Save  FSN002, an endophyte isolated from the catalpa tree, can develop different pellet forms in fermentation. Therefore, different pellets were selected as strains and fermented, and the anti-cancer test was done and HPLC of corresponding fermentation broth was analyzed. The results show that yellow substances in the fermentation broth consist of the medium hydrophobic substance with anticancer activity and other yellow impurities. The large pellet with surrounding fimbria (A) is characterized by high production，and produces more yellow substances, while the purity of the active substance is lower than 60% based on HPLC peak area. The squid-like pellet with a small head and long tail (D) is interesting because of its high purity of the yellow active substance and the feasibility of the following purification. References | Related Articles | Metrics

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Expression of a Chaining miR-shRNA for Simultaneous Knockdown of srGAP Family Members MA Yue, DAI Yun-Kai, CHEN Keng, MI Ya-Jing, JIN Wei-Lin 2012, 46 (05):  803-807.  Abstract ( 2784 )   Save To resolve the partial compensation effect of the different srGAPs in neuronal development, a miR-shRNA expression system was constructed which can down regulate srGAP family members srGAP1—3 simultaneously. Multiple miRshRNA oligos targeting different srGAPs were designed, synthesized and then inserted into the miRNA expression vector to generate miRshRNA against srGAP1—3 respectively. Western blot was performed to detect the knockdown effect of different miR-shRNAs, the three miRshRNA with the most obvious knockdown effect to srGAP1—3 respectively were selected. Then the miR-shRNAs were chained together in one vector to generate a chaining miRshRNA expression vector. The results show that the effective miRshRNA against corresponding srGAP1—3 are generated and named J17, J24 and J33. Furthermore, the chaining miR-shRNA J1+2+3 against srGAP1—3 is obtained. References | Related Articles | Metrics

General Industrial Technology

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Biomimetic Actuator Design Based on the Mechanism of Antagonism MA Quan-Chao, WANG Ming, LUO Yun 2012, 46 (05):  808-812.  Abstract ( 2279 )   Save Emulating the antagonism of the muscles, a new actuator with the characteristic of conversion between the antagonistic energy was designed. Permanent magnets with high energy density and polymers with fine motion performance were respectively used as the agonistic and antagonistic components of the actuator. Antagonism of the magnetic and elastic energy was analyzed theoretically. Electromagnetic coils were designed as trigger of the antagonism of the magnetic and elastic energy, and its effectiveness was confirmed by experiments.  It was concluded that the actuator with characteristic of the conversion between the antagonistic energy can work effectively. References | Related Articles | Metrics

Others

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Effects of Surfactants on the Properties of Kudzu (Pueraria Lobata) Starch Films ZHONG Yu-a, b , LI Yun-Fei-b, c 2012, 46 (05):  813-818.  Abstract ( 3264 )   Save An edible film based on kudzu starch was prepared and the effect of the surfactant on physical and mechanical properties of the films was evaluated. For the film, glycerol as the plasticizer was added in the solution, besides tween 20 and span 80 were used as surfactants. It was found that each surfactant decreases surface tension of the filmforming solution, promotes the formation of V-type crystal in the film, decreases the mechanical strength and increases the flexibility of the film. Tween 20 improves the wettability of film-forming solution on both glass and paraffin wax substrates, smoothes the surface of the film and increases the film’s solubility. The film containing only tween 20 is rougher but has lower hygroscopicity than other films. Blendedsurfactant does not effectively improve the properties of the film as regarding the film containing single surfactant. References | Related Articles | Metrics

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Effect of Vacuum Treatment on the Microstructure and Properties of Onion Epidermis SONG Xiao-Yong-a, b , LI Yun-Fei-b, c 2012, 46 (05):  819-824.  Abstract ( 3185 )   Save  A miniaturized and visual experimental setup was developed for real time observation of structural changes at the cellular level related to vacuum treatment of onion epidermis. The ultrastructure and changes of mass, conductivity and mechanical properties were studied to analyze the microstructure modifications induced by vacuum treatment. The results show that the color in the intracellular region, surface morphology as well as spaces between the cell membrane and the cell wall change with time because of the microstresses due to water transfer and pressure changes. The tensile strength of the onion epidermis is decreased, and the conductivity is increased. References | Related Articles | Metrics

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Pricing Value Difference between Barrier and Vanilla Options with Binomial Pricing Method HU Wen-Wei-1, LI Zhan-2 2012, 46 (05):  825-831.  Abstract ( 3376 )   Save  The binomial pricing method was adopted to build a pricing model for the value difference between barrier and vanilla options which are different only in barrier, as well as the impacts of several key factors on the price difference. The outcomes indicate that the value of the barrier option is lower than that of the vanillar option. Moreover, for the downandout call options, the price difference gets bigger with any of the situations which are higher barrier, higher call price, longer maturity, lower underlying asset price, and smaller expected return rate or bigger volatility of the underlying asset price. References | Related Articles | Metrics

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FEM Analysis on the Buckling of a Long Steel Jacking Pipe CHEN Nan, CHEN Jin-jian, XIA Xiao-he, WANG Jian-hua, ZHONG Jun-bin 2012, 46 (05):  832-836.  doi: 10.16183/j.cnki.jsjtu.2012.05.031 Abstract ( 3762 )   HTML ( 168 )   PDF (584KB) ( 722 )   Save The buckling of steel jacking-pipe under complex loads has been an important factor in construction because of the increasing of diameter and jacking distance. Numerical analysis on the buckling of long steel jacking pipe, whose distance-diameter ratio is larger than 100, is studied in this paper with finite element method (FEM). The first buckling mode of pipe-jacking under different loads are obtained by the buckle analysis. By introducing the first mode as the initial imperfection, the elastic-plastic buckling behavior of steel pipes is analyzed with the RIKS method. Both the buckling mode and ultimate load of buckling of the steel jacking pipe are discussed, and the buckling phenomenon in practice is verified. Parametric analysis shows that the stability of steel pipe can be improved by reducing friction and face resistance of pipe-jacking, and the jacking load of the pipes with high confining pressure should be carefully controlled. Figures and Tables | References | Related Articles | Metrics