Journal of Northeastern University(Natural Science)

Utilizing Multilevel Community Center Labels for Distance Querying in Large Graphs

ZHANG Yi-fei， WANG Guo-ren， ZHANG En-de， ZHAO Chang-kuan

2015, 36 (5): 609-613. DOI: 10.12068/j.issn.1005-3026.2015.05.001

Abstract ( 503 )

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Distance querying is one of the most fundamental operations in many graph data mining applications. However， most of the previous methods cannot handle large graphs， especially those with more than a hundred thousand vertices. To solve this problem， a multilevel community center labels index structure was proposed. Firstly， the vertices of the original graph were divided into different communities. Then a weighted query sub-graph was constructed by each community center. Finally， a tree-like label set was built for every vertex. The query efficiency could be improved greatly with small time and storage cost. The experimental result showed that the overall efficiency of this approach is significantly better than those of the-state-of-the-art algorithms.

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A New Complex Blind Source Separation Algorithm Based on Standard Kurtosis

JI Ce， WANG Yan-ru， WANG Xiao-yu

2015, 36 (5): 614-617. DOI: 10.12068/j.issn.1005-3026.2015.05.002

Abstract ( 551 )

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In the complex blind source separation algorithm， the complex signal kurtosis maximization is often used as the cost function. The complex standard kurtosis was used instead of complex kurtosis as the new cost function for optimimization， and a modified complex quasi-newton iterative algorithm was employed to optimize the cost function. The algorithm was applied to separate mixed QAM signal， and simulation results showed that the improved algorithm has a good separation effect. Compared with the algorithm of the kurtosis maximization as the cost function， the convergence performance was improved obviously.

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A Strategy Self-Adaptive Selection Bee Colony Algorithm Based on Feedback

LIU Ting-ting， ZHANG Chang-sheng， ZHANG Bin， SUN Ruo-nan

2015, 36 (5): 618-622. DOI: 10.12068/j.issn.1005-3026.2015.05.003

Abstract ( 649 )

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Employed bee foraging strategies have a greater impact on the performance of artificial bee colony algorithm. The single foraging strategy is difficult to apply to all the search space of the problems. And the different stages of the algorithm performs differently by using different employed bee foraging strategies.How to choose the best foraging strategy is very important for the given function optimization problem. To solve this problem， a strategy self-adaptive selection colony algorithm was presented， based on feedback. The optimal foraging strategy could be automatically selected for the given problem during the optimization process using the praposed algorithm. Experimental results showed that compared with the ABC (artificial bee colony algorithm)， the PSO (particle swarm optimization algorithm)， the DE (differential evolution algorithm)， and the GA (genetic algorithm)， the optimization capability of the SSABC algorithm has been improved greatly.

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Research on Schema of Fuzzy Spatiotemporal XML Data

BAI Lu-yi， YAN Li， MA Zong-min， XU Chang-ming

2015, 36 (5): 622-625. DOI: 10.12068/j.issn.1005-3026.2015.05.004

Abstract ( 619 )

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In order to manage fuzzy spatiotemporal XML data， several fuzzy constructs are integrated in XML documents. Consequently， Schema of XML documents need to be fuzzy spatiotemporal extended. In the meantime， the integrated constructs should be compatible by modifying Schema of XML documents. Fuzzy spatiotemporal XML data model was formally proposed firstly. Subsequently， Schema of the OID part， the ATTR part， the FP part， the FM part， and the FT part in fuzzy spatiotemporal XML data model were extended， respectively. In succession， an example was introduced to give illustrations. After extending Schema， the XML documents were compatible with fuzzy spatiotemporal information， which was easy to manage fuzzy spatiotemporal XML data. What’s more， it could be further used for representing， reasoning， and querying fuzzy spatiotemporal XML data.

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Risk Control of the Spacecraft Development Based on Comprehensive Weight C-TOPSIS

ZHANG Zhi-feng， BAI Yan

2015, 36 (5): 626-630. DOI: 10.12068/j.issn.1005-3026.2015.05.005

Abstract ( 610 )

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By analyzing the risk of the spacecraft developing evaluation index， a risk control model was built based on comprehensive weight TOPSIS. In this model， the subject and the object weight were calculated by AHP and entropy-weight method. The linear programming was used to count the comprehensive weight. And TOPSIS method was optimized by using “vertical plane projection method” to substitute existing opposite continental distance， resulting in improving the precision of evaluate. The risk evaluated target was clustered， and the different sort target system was set up， resulting in predigesting the process of the operation. In the end， the best scheme was selected by combining the example of spacecraft development control. The result showed the feasibility of the developed method.

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The Analysis of the RF Spoiling for Phase-Contrast Magnetic Resonance Imaging

ZOU Yun-peng， FU Chang-xin， KANG Yan

2015, 36 (5): 631-635. DOI: 10.12068/j.issn.1005-3026.2015.05.006

Abstract ( 685 )

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The effects of RF spoiling was investigated in GRE based 2D phase contrast (PC) MRI.Simulation， flow phantom experiments and in vivo experiments were used to evaluate the effects of RF spoiling in quality of PC MRI image and accuracy of measured flow. The measurements of blood flow with 2D through-plane PC-MRI indicated that there was no difference when sufficient gradient spoiling was applied with or without RF spoiling， but there was a much better result when insufficient gradient spoiling was applied with RF spoiling compared with that without the RF spoiling. And it was also found that the CNR(contrast noise ratio) of the PC-MRI image could be increased with RF spoiling， which made it easier to differentiate the flow and stationary tissue.

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QCT Method Based on Liquid Phantoms for Jaw Bone Density Measurement Using Oral CT

CHEN Xiao-zhao， FU Quan-hai， SUN Zhi-yong， KANG Yan

2015, 36 (5): 636-640. DOI: 10.12068/j.issn.1005-3026.2015.05.007

Abstract ( 769 )

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The current four most commonly used methods to evaluate the jaw bone mineral density was summarized， and the shortage of these methods was analyzed. Quantitative computed tomography (QCT) method was proposed and used for oral cone beam CT (CBCT) based on K₂HPO₄ liquid phantoms， and specific measurement method was described. Meanwhile the K₂HPO₄ liquid phantoms uniformity， the linearity， and the stability were tested， and were contrasted with the solid phantoms. The test results showed that the CBCT bone density measurement results based on K₂HPO₄ liquid phantoms were equivalent with the results of the conventional CT based on solid phantoms. Meanwhile， in view of the low production costs， convenient and flexible configuration， this method was worthy of clinical promotion and application.

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Non-metallic Inclusions and Its Effect on Microstructure of Zr Deoxidized Steel

WANG Chao， WANG Guo-dong

2015, 36 (5): 641-645. DOI: 10.12068/j.issn.1005-3026.2015.05.008

Abstract ( 630 )

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Transformation behaviors of a Zr deoxidized and Ti microalloyed low C-Mn steel under continuous cooling and isothermal treatment were studied. The precipitation of non-metallic inclusions and its influence on the microstructure were analyzed. Statistical results showed that the inclusions are mainly ZrO₂·MnS and ZrO₂·MnS·TiN composites， which are in accordance with thermodynamic analysis. The size of inclusions is in the range of 0.2~1μm and the number density of inclusions is high. Intragranular acicular ferrite is obtained under both conditions of continuous cooling with 1℃/s and isothermal treatment at 500℃. Inclusions， which can promote ferrite nucleation， are mostly ZrO₂·MnS·TiN type. Formation of Mn-depletion zone with MnS precipitation on the ZrO₂ core is an important factor in ferrite nucleation. Composite precipitation of TiN can reduce the interface energy of ferrite nucleation， which can further promote acicular ferrite transformation.

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Study on Solidification Contraction of Aluminum Alloys

LE Qi-chi， LI Hao-yu， BAI Yuan-yuan， ZHANG Hai-tao

2015, 36 (5): 646-650. DOI: 10.12068/j.issn.1005-3026.2015.05.009

Abstract ( 683 )

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An equipment was developed to study the solidification characteristics during free and blocked contraction. The solidification contraction behaviors of 5083， 6061 and 7075 aluminum alloys were investigated to predict the hot cracking tendency， and the stress accumulating coefficient (k) was introduced to evaluate the hot cracking tendency. The results indicated that the equipment can record the subtle changes of temperature， thermal shrinkage displacement and shrinkage stress during solidification. Combined with the calculation of thermal software JMatPro， four solidification stages are proposed. The sequence of hot cracking tendency of three investigated alloys is k(5083)＞k(7075)＞k(6061)， which coincides with the result during reality casting and the result of CSC. All the results indicate that the developed equipment and the data analysis method are available， and k can be used to predict accurately the hot cracking tendency of aluminum alloys.

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Static Model of Iron Bath Smelting Reduction Process with Thick Slag Layer

HE Yi-bo， LI Cheng-zhi， WEI Guo， ZOU Zong-shu

2015, 36 (5): 651-655. DOI: 10.12068/j.issn.1005-3026.2015.05.010

Abstract ( 492 )

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A two-step three-segment iron bath smelting reduction process with thick slag layer was proposed. The thick slag layer in the smelting reduction vessel was adopted to ensure the separation between the oxidation exothermic of oxidation zone and the reduction of reduction zone. The use of gas reforming furnace improved the gas utilization rate， and the use of rotary hearth furnace pre-reduction matched energy consumption of whole system to be lowest. Based on the material balance and energy balance principle， a static model of the process was established. According to all set aspects of process in production， the mass consumption and energy consumption were obtained and compared with other ironmaking processes to clarify the characteristics and advantages of the present process， which could provide a reference to the production practice.

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Effects of MgO Content in Sinter on Softening-Dripping Behavior of Vanadium-Titanium Magnetite Composite Burdens

LIU Zheng-gen， CHU Man-sheng， CHEN Li-jie， FU Xiao-jiao

2015, 36 (5): 655-659. DOI: 10.12068/j.issn.1005-3026.2015.05.011

Abstract ( 702 )

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Effects of MgO content in sinter on softening-dripping behavior of vanadium-titanium magnetite composite burden and the migration patterns of V， Cr in slag-iron were studied. The results showed that with the increasing of MgO in sinter， the softening range t₄₀-t₄ tends to be wider，the melting range t_D-t_S is narrowed slightly. The cohesive zone tends to be narrow and its location is shifted down but not obvious. Softening-dripping characteristics S decreases at first then increases， the permeability tends to be better then worse， when the content of MgO is between 2.98% and 3.40%， the permeability is the best. The dripping ratio tends to be declining; when MgO is increased， it is not conducive to the reduction of V， Cr. The optimal content of MgO in the sinter is around 3.40% and the content of MgO in BF slag is about 12%.

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Numerical Investigation of Gas Flow in Vertical Tank for Recovering Sinter Waste Heat

FENG Jun-sheng， DONG Hui， ZHAO Yong

2015, 36 (5): 660-664. DOI: 10.12068/j.issn.1005-3026.2015.05.012

Abstract ( 650 )

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Based on the porous media model， the mathematical model of the gas flow in sinter vertical tank was established according to the gas solid packed beds dynamic theory， and the boundary conditions of the mathematical model were determined．This model was conducted on the platform of FLUENT software. The radial voidage distribution of tank material layer was defined through the user defined functions (UDF). The basic law of the gas flow in vertical tank was studied and the main factors and influence rules influencing the gas flow distribution were discussed. The results showed that in the cooling section， the gas flow rate gradually increases from the tank center to the inner wall along the radial， and finally increases suddenly near the inner wall. The main factors that influence the gas flow distribution in vertical tank are the radial voidage distribution of bed layer and the pre-stored segment diameter. The more serious the voidage radial segregation is， and the larger the pre-stored segment diameter is， the more uneven the gas flow distribution in vertical tank is.

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Experimental Studies on Removal of CO₂ from Gas by Absorption Employing a Bubble Column

QIN Qin， HE Dan-ni， YU Qing-bo， LI Jun

2015, 36 (5): 665-669. DOI: 10.12068/j.issn.1005-3026.2015.05.013

Abstract ( 638 )

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In order to absorb the CO₂ in coal-fired flue gas， semi-continuous experimental studies for CO₂ capture using chemical method were carried out with bubbling column reactor. According to the orthogonal experiment and the calculation of the removal rate， the research focused on the effect of absorbent type， gas temperature， flow rate， CO₂ content， liquid level and absorbent concentration on the CO₂ absorption. The results showed that the ammonia is one of the best absorbent， and the impact of the gas temperature is minimal. The influences of ammonia concentration， liquid level， flow rate and CO₂ concentration on removal rate， absorption capacity and absorption rate are obtained by single factor experiments using ammonia solution.

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Bio-degradation of Activated Carbon by Rhodopseudomonas spheroides

LIU Qian， YANG Hong-ying， TONG Lin-lin， QIAO Li-li

2015, 36 (5): 670-674. DOI: 10.12068/j.issn.1005-3026.2015.05.014

Abstract ( 545 )

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The effect of Rhodopseudomonas spheroides on the degradation and the gold adsorption capacity of activated carbon were investigated， and activated carbon was used as a substitute of carbonaceous materials in carbonaceous gold ores. The optimum process conditions of bio-degradation of activated carbon were confirmed by orthogonal experiment， i.e. the granularity was <74μm， the pulp mass concentration was 5%， the degradation time was 14d and the microbial quantity was 1mL/100mL. Under the optimum process conditions， the bio-degradation rate of activated carbon reached to 28.35%. The gold-adsorption tests showed that Rhodopseudomonas spheroides decreased the gold-adsorption capacity of activated carbon， about 11.46%. The micro-crystalline structure of activated carbon and some of the aromatic ring structures were distorted， and the content of oxygen-containing groups and aromatics was increased. These indicated that Rhodopseudomonas spheroides is an available bacterium， which can be employed to reduce the preg-robbing capacity of carbonaceous matter.

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Preparation of Graphite Coating on Nickel Substrate by Molten Salt Electrolysis

LI Liang-xing， LIU Ai-min， XIE Kai-yu， SHI Zhong-ning

2015, 36 (5): 675-679. DOI: 10.12068/j.issn.1005-3026.2015.05.015

Abstract ( 711 )

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Graphite coating was prepared on nickel cathode by electrochemical reduction of carbonate ion in LiF-Li₂CO₃ molten salt. The electrochemical behavior of carbonate ion was investigated using cyclic voltammetry. The influences of temperature and deposition potential on surface morphology of the coating were studied by scanning electron microscopy and the property of the coating was analyzed. The results showed that the electrochemical reduction of carbonate ion to form carbon is an irreversible process. The cathode coating deposited at 690℃ and -1.5V is jagged combined between the carburized layer and nickel substrate. The surface of coating prepared at -1.1V has a spherical particles appearance， while the surface of coating prepared at -1.7V appears a whisker structure. The corrosion potential of nickel in 3.5%NaCl solution increases by 739mV because of the formation of graphite coating.

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Research on Leaching of Calcification Transition Slag of Bastnaesite

DOU Zhi-he， LIU Jiang， ZHANG Ting-an， HUANG Yu-kun

2015, 36 (5): 680-684. DOI: 10.12068/j.issn.1005-3026.2015.05.016

Abstract ( 530 )

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The new technology of bastnaesite in calcification transition decomposition-acid leaching to extract rare earth was proposed. The pressurized DSC was used to investigate the kinetics of calcification transition slag in acid leaching. The leaching effects of leaching temperature， acid concentration， leaching time， liquid to solid ratio were studied. The results showed that the acid leaching reaction of calcification transition slag can take place at room temperature of 30℃， and the apparent activation energy and reaction order are 0.014kJ/mol and 0.11， respectively. The appropriate strengthening acid leaching conditions are the leaching temperature of 80℃， the concentration of hydrochloric acid of 1 mol·L^-1， the leaching time of 30 min and the liquid-solid ratio of 15∶1.

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Reaction Behaviors of CaO-TiO₂-SiO₂-NaAlO₂ System

WANG Yan-xiu， ZHANG Ting-an， LYU Guo-zhi， ZHU Xiao-feng

2015, 36 (5): 685-689. DOI: 10.12068/j.issn.1005-3026.2015.05.017

Abstract ( 566 )

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Reaction behaviors of CaO-TiO₂-SiO₂-NaAlO₂ system (anatase mainly) was investigated. The equilibrium phase and relatively stable level were determined by means of thermodynamic calculation. The reaction order， activation energy and reaction control mechanism were determined through kinetics analysis. The reaction behaviors were analyzed by calcification experiments. The results showed that the reaction behaviors of CaO-TiO₂-SiO₂-NaAlO₂ system are as follows: under given conditions (the mass ratios of m(TiO₂)/m(CaO) and m(TiO₂)/m(SiO₂) are 1.42 and 0.49， respectively， the time is 1h， the stirring speed is 300r/min， the mass concentration of Na₂O (m_k) is 220g/L and the molar ratio of Na₂O and Al₂O (α_k) is 3.1)， TiO₂ reacts with alkali liquor to produce Na₂TiO₃， then reacts with NaAl(OH)₄ and Na₂SiO₃ to produce Al₄Ti₂SiO₁₂. With the increase of temperature， Al₄Ti₂SiO₁₂ decomposes and sodium aluminosilicate hydrate and hydrogarnet form，the peak intensity of CaTiO₃ increases and CaTiO₃ becomes the main part of calcified slags. Finally， anatase converts to stable CaTiO₃. The initial transition temperature is 260℃.

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Impact of the System Parameters on Self-excited Vibration System Dynamic Stability

LI Xiao-peng， LIANG You-jian， SUN De-hua， YUE Bing

2015, 36 (5): 690-694. DOI: 10.12068/j.issn.1005-3026.2015.05.018

Abstract ( 688 )

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The friction self-excited vibration system model with the plastid-spring-conveyor belt based on the Stribeck friction model was built to study the stick-slip kinetic characteristics of machine feed system. The stability of equilibrium point of self-excited vibration system was analyzed through the Lyapunov stability criterion， and the critical instability speed of the system was obtained， and then the critical stick-slip speed of the system was deduced from the theoretical formula. The phase diagram and the Poincare section diagram through the numerical simulation show that with the increase of machine feed rate， damping and stiffness of transmission and with the decrease of dynamic-static friction difference， the duration of stick-slip will be shorter， and the stability of the system increased. The self-excited vibration with low speed condition is divided into stick-slip and pure sliding， and they are both periodic motion. The feed velocity is important for the stability of the system.

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Establishment of Model of Damping Mechanism for the Hard-Coating Cantilever Beam

SUN Wei， JIA Shi， LIU Ying

2015, 36 (5): 695-698. DOI: 10.12068/j.issn.1005-3026.2015.05.019

Abstract ( 566 )

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Unable to confirm the contribution of hard coating damping on the whole system effectively， it becomes very difficult to establish the analytical model of hard coating composite structure of vibration reduction mechanism. The method of creating the damping mechanism model of beam was studied through separating the damping contribution of hard coating. First of all， the cantilever beams before/after coating were tested and the vibration characteristics parameters， such as natural frequency， damping ratio and vibration response were obtained. Moreover， by analyzing the energy stored and dissipated in the uncoated and coated beam， the damping contribution of hard coating was confirmed. At last， the Oberst beam theory was adopted to create the damping mechanism model of cantilever beam， with both material and viscous damping considered， and the correctness of analytical model was also verified. It shows that by using the hard-coating damping and the equivalent viscous damping of uncoated beam， the reasonable analysis model of coated beam can be created.

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A Calculation of the Crawler Crane Boom System′s Dynamic Load in the Lifting Process

LIN Gui-yu， LI Zhao-yong， WANG Zhen-guan， LI Kui-xian

2015, 36 (5): 699-703. DOI: 10.12068/j.issn.1005-3026.2015.05.020

Abstract ( 664 )

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To obtain the elastic element’s dynamic load under the action of slope pulse load in the lifting process， we simplified the crawler crane boom system as a linear vibration model with two degrees of freedom. Through the motion analysis， the geometry equations of deformation caused by elastic element’s vibration was established. The vibration mathematical model of the slope pulse load was established through energy’s method， and we also used superposition principle method to calculate elastic element’s the response，including displacement，velocity，acceleration and dynamic load coefficients of the linear vibration system with the greatest loading， under the slope pulse load. The effective control method can not only connect with the major factors about the dynamic load， but also provide practical basis for the equipment’s working performance.

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Aircraft Part and Its Assembly Fixture Model Based on Multi-domain Integrated Mapping

XU Kai-yuan ， QU Rong-xia， WANG Jian-xi

2015, 36 (5): 704-708. DOI: 10.12068/j.issn.1005-3026.2015.05.021

Abstract ( 542 )

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Considering the problem of aircraft part assembly fixture collaborative design and assembly data expression， the modeling process of aircraft assembly object and its fixture multi-domain integration was discussed. The modeling process provides the knowledge framework of multi-domain integration model. The information composition of all domain， and describe all the data in the assembly process field were defined. At the same time， the mapping mechanism between assembly object and assembly fixture， and elaborate four key knowledge points included in mapping process was proposed. Finally， the effectiveness and feasibility of the method are demonstrated by winglet example， making it more systematic and improving the response speed & the collaborative design efficiency of aircraft structure， assembly process planning， and tooling design.

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Effect of Sun Gear Manufacturing Eccentric Errors on Dynamic Performances of Herringbone Planetary Gear Train

QIN Da-tong， REN Fei， WU Xiao-ling

2015, 36 (5): 709-714. DOI: 10.12068/j.issn.1005-3026.2015.05.022

Abstract ( 627 )

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Based on the structure of herringbone gears and using the lumped-parameter method， a generalized dynamic model of a herringbone planetary gear train (HPGT) was presented to study the forced vibration characteristics. Taking into account the manufacturing eccentric errors and tooth profile errors， bearing stiffness， time-varying mesh stiffness， and gyroscopic effect， the model can be utilized for the vibration performance analysis with different types of manufacturing errors and arbitrary number of planets. The forced vibrations of an HPGT were numerically computed with the presented model， and analyzed in time and frequency domain， respectively. The effects of manufacturing errors especially the sun gear eccentric error E_s on dynamic characteristics were discussed， revealing that manufacturing error excitations， such as the sun gear eccentric error E_s， enhance the dynamic responses and dynamic mesh force fluctuations in HPGT.

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Optimum Design of TBM Mucking Slot Based on the Rock Ballasts Fluidity

HUO Jun-zhou， CHEN Wei， OUYANG Xiang-yu， ZHANG Xu

2015, 36 (5): 715-718. DOI: 10.12068/j.issn.1005-3026.2015.05.023

Abstract ( 617 )

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The optimum design of TBM mucking slot under certain open area was studied. By introducing the discrete element method， we took design parameters of mucking slot and its quantitiess as variables， and made a series of TBM rock ballast liquidity simulation experiments. We proposed a design method of mucking slot providing the same opening area of the cutterhead. First， the design should use the symmetrical arrangement as possible. Second， it should be more rational as long as the arrangement of alternating between long and short mucking slot is used. Third， the width of long mucking slot should be decreased for the stability of discharging ballasts. Take the numerical simulation results of the Yintao project comparing with the original design as an example， the efficiency and stability of discharging ballasts has been increased by 15.08% and 11.97%， respectively.

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Experimental Study of the Charge Air Cooler Arrangement for Engine Cooling Performance

ZHANG Wei， YANG Jue， ZHANG Wen-ming， ZHAO Xuan

2015, 36 (5): 719-723. DOI: 10.12068/j.issn.1005-3026.2015.05.024

Abstract ( 684 )

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To better combine the charge air cooler and radiator into turbo engine， a research was proposed to influence the performance of cooling system and the engine itself. The various layouts of charge air cooler with different cooling mediums and radiators were tested via wind tunnel and engine cooling system bench. The result shows that the layout is a vital factor to cooling efficiency， thermal distribution and wind resistance， etc. As for air medium， parallel arrangement has better wind resistance and cooling efficiency than that of cascade arrangement， which， however， is well-distributed. As for water medium， the effect is insignificant. The optimal layout form can be selected based on the cooling medium and installing space.

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Coalbed Gas Content Prediction and Controlling Factors Analysis of Coalbed in Junlian Muai Area at South of Sichuan

LI Jin-shan， YANG Min-fang， ZHU Wei-yao， SUN Sheng-lin

2015, 36 (5): 724-728. DOI: 10.12068/j.issn.1005-3026.2015.05.025

Abstract ( 667 )

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The model to predict the relation between coal seam floor elevation and gas content is established by fitting the existing data of coal seam gas. By using the model， the gas content distribution in main coal seam 8^# is predicted according to coal floor elevation data obtained through seismic interpretation. Through the latter data validation， the prediction accuracy is found to be above 85%. The result show that the greater the distance to fault the higher the prediction accuracy， in which the error is between -1.86m³/t and 4.32m³/t. It is considered that the coal gas content is controlled by coal floor elevation， besides， the complex small-scale faults have two effects that may induce gathering or scattering of coal bed methane. So distribution of geologic structures should be considered as the priority for CBM target in the study area.

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3D Image Measurement of Triaxial Testing Using Two CCD Cameras

ZHAO Hong-hua， YU Shen-kun， CHANG Yan， GUO Chang-bao

2015, 36 (5): 728-732. DOI: 10.12068/j.issn.1005-3026.2015.05.026

Abstract ( 720 )

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A three-dimensional digital image measurement technique by using two CCD cameras placed at the front and back of the triaxial testing machine， respectively， was proposed. A plastic membrane with white and black grids was used to replace the traditional plastic membrane. The images of the specimen obtained during the triaxial testing were able to capture the deformation of the whole specimen surface. By extracting and tracking the corner points of white and black grids， and detecting the edge of the specimen， the front and back images were stitched together and three-dimensional deformation measurement of the soil specimen was realized based on the assumption that the horizontal cross section of the soil specimen will keep horizontal circular plane before and after deformation. By combining with the numerical analysis with ANSYS finite element software， 3D surface strain contour can be obtained. This technique was applied to triaxial testing of diatomite and it achieved very good measurement effects.

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Research on Shenyang′s Industrial Real Estate:Based on the System Dynamics Model

QI Xi-jing， HUANG Wen-hua，ZHAO Liang

2015, 36 (5): 733-737. DOI: 10.12068/j.issn.1005-3026.2015.05.027

Abstract ( 628 )

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A simulation analysis was given on the current situation of Shenyang’s industrial real estate. Taking the influencing factors of industrial real estate as a whole， an integration analysis was made with the system dynamics model. In terms of the problems of land， capital， approving and property existing in Shenyang’s industrial real estate，several solutions were put forward so as to provide the theoretical basis for Shenyang municipal government to take macro-control over industrial real estate——establishing a unified market for urban and rural construction land， adjusting the structure of land supply， continuing to implement the intensive utilization of land; trying to explore the “several in one” regulatory mechanism， improve the service work and create a good soft environment; seeking a diversified financing approach by the government and the developers; and striving to increase the intensity of investment， perfecting the planning and designing， and clarifying the industry positioning.

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Research on the Risk Evaluation Model for Composite Techniques and Its Field Application

YAO Xi-wen，XU Kai-li，YAN Fang，TANG Gui-cheng

2015, 36 (5): 737-742. DOI: 10.12068/j.issn.1005-3026.2015.05.028

Abstract ( 622 )

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Taking into full account the complex process of a petrochemical plant， a risk evaluation model based on Bayesian networks for composite techniques was built， which integrates HAZOP， LOPA and Bow-tie analysis. Firstly， the system fault tree was prepared， which was mapped into corresponding Bayesian networks， and the GeNIe software was utilized for fault prediction and diagnosis with the two-way reasoning of Bayesian networks and for locating the Bayesian risk fault node which most likely leads to accidents. Secondly， the causes and consequences of deviation occurring in the node parameters were studied by combining HAZOP and LOPA， and the risk level was confirmed through the failure probability of identified protection layers. Lastly， Bow-Tie analysis was applied to the remaining higher risk events for identifying the key activities to continuously sustain IPL effectively and then preventing the serious technique safety accidents from happening. Moreover， this risk evaluation model was put into use in the delayed coking device of Liaohe Petrochemical Company.

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A New Semi-active Control Algorithm for Suppressing the Vibration of Multi-storey Buildings

MA Yong-quan， QIU Hong-xing， QI Yong-cheng

2015, 36 (5): 743-747. DOI: 10.12068/j.issn.1005-3026.2015.05.029

Abstract ( 673 )

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To effectively suppress the seismic responses of multi-storey buildings， a new adaptive neural network control strategy based on the modified genetic algorithm (MGA_ANNC) was proposed. First， the reference trajectory of uncertain and nonlinear structures was tracked， and the tracking accuracy was ensured by using the radial basis function network. Next， the initial values of consequent parameter vectors were selected by using the modified genetic algorithm. Finally， the semi-active control strategy MGA_ANNC/MCO used for TM-MRD was proposed by using the modified clipped optimal (MCO) control algorithm. The various evaluation criteria of a 9-storey frame structure under the non-control， MGA_ANNC/MCO semi-active control， MGA_ANNC active control and linear quadratic gaussian (LQG) active control were calcalated， respectively. The results indicated that the seismic reduction effects of both MGA_ANNC/MCO and MGA_ANNC are obviously superior to those of LQG.

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Strategic Choices Between Enterprise Merging and Technology Licensing:Based on Different Competition Modes

QI Yong， HOU Ze-min ， CAO Feng-wen

2015, 36 (5): 748-752. DOI: 10.12068/j.issn.1005-3026.2015.05.030

Abstract ( 486 )

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By setting up a duopoly Bertrand competition mode with quality differences， the cost-reducing technology for transferring non-productive R & D firms was explored， the technology licensing and merging was analyzed， and the effects of different competition modes were studied. The results showed that non-productive R & D firms prefer a merger with high quality enterprises， and the licensing depends on the differentiation of goods quality and the degree of technology innovation in the two-part tariff， which may in turn deteriorate social welfare. In the case of minor innovation， R&D firms are supposed to opt for technology licensing; otherwise， they should choose merging. Different competition modes tend to exert varied effects on the technology transfer of non-productive R&D firms; therefore， a strategy should be adopted that takes into account licensing， merging and competition modes.

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Research on the Degree of Dynamic Inconsistency in Intertemporal Decision Making

LU Yang， ZHUANG Xin-tian

2015, 36 (5): 753-756. DOI: 10.12068/j.issn.1005-3026.2015.05.031

Abstract ( 740 )

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The parameters and AICc (Akaike information criterion with small sample correction) of intertemporal choice models (exponential， simple hyperbolic， quasi hyperbolic and q-exponential) for undergraduate students and MBA students were estimated respectively. Meanwhile， two methods indicating the degree of inconsistency were compared. The results showed that the q-exponential discount model always generates the minimum AICc value regardless of working experience， and it is thus regarded as the optimal discount model; the method based on the logarithmic time-perception theory captures the essence of dynamic inconsistency， and it thus serves as the optimal approach to measure the degree of dynamic inconsistency.

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Measurement of the Methanol Permeability of Polybenzimidazole Membrane Electrolytes with Cyclic Voltammetry

YANG Jing-shuai， LI Xue-yuan， XU Yi-xin， HE Rong-huan

2015, 36 (5): 757-760. DOI: 10.12068/j.issn.1005-3026.2015.05.032

Abstract ( 863 )

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A method for measuring the methanol permeability of phosphoric acid doped polybenzimidazole (PBI) membranes was developed by using cyclic voltammetry (CV). The methanol permeability of PA doped PBI membranes at different acid doping levels was investigated under a voltage range of -0.2~1.2V and at a potential sweep rate of 100mV/s using phosphoric acid solutions as electrolytes. The results indicated that using the PA solution with a suitable concentration as the electrolyte could maintain the acid doping level of the PBI membrane and ensure a precise and reliable result. Compared with that of the pure PBI membrane (1.34×10^-8cm²/s)， the methanol permeability of acid doped PBI membranes increased， i.e.， 3.2×10^-8~14×10^-8cm²/s， corresponding to the acid doping level of 2.5~3.2.

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