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Journal of Jiangsu University(Natural Science Eidtion)

	2017 Vol.38 Issue.4 Published 2017-07-10

	Article

Article

	373	Experiment on characteristics of soot oxidation from diesel engine with Ce-based FBC fuel
		LIU Jun-Heng, SUN Ping, JI Qian, HAO Hui-Min, SHEN Hui
		To investigate the effects of Ce-based fuel borne catalyst (FBC) on the catalytic oxidation of soot from diesel particles, naphthenic acid cerium solution was selected as FBC. Ce element was blended with diesel fuel with the ratios of 50, 100, 150 and 300 mg?kg-1 (mass fraction) and marked as F50, F100, F150 and F300, respectively. The experiments on smoke emission, particle size, soot oxidation characteristic and diesel particulate filter (DPF) catalytic regeneration were conducted on a light-duty diesel engine with FBC fuels. The experimental results show that FBC fuels can improve the fuel economy and reduce the exhaust temperature and smoke emissions. The particle mass distribution moves to the small particle size, and the proportion of accumulation mode particles is increased with decreased proportion of coarse mode particles for engine with FBC fuels. The soot oxidation temperature is decreased with the increasing of FBC ratio, and the DPF regeneration temperature can be reduced with FBC fuels.
		2017 Vol. 38 (4): 373-378 [Abstract] ( 1211 ) [HTML 1KB] [ PDF 2081KB] ( 1807 )

	379	Double-pedestrian deformable part model and its application in pedestrian detection
		CAI Ying-Feng-1, LIU Ze-2, SUN Xiao-Qiang-1, CHEN Long-1, WANG Hai-2
		To solve the problem that the traditional pedestrian detection algorithm was prone to missing detection for close or close to each other multi-pedestrian targets, a pedestrian detection algorithm was proposed based on two-pedestrian deformable part model. Model training, model matching and fusion process were included in the algorithm to obtain a double pedestrian deformable part model, and a new method of sub-region matching and fusion was also proposed. Two groups of experiments were designed to compare the effect of single-person deformable part model and double pedestrian deformable part model. The results show that compared with other algorithms, the proposed algorithm is more easy to detect close to each other multi-pedestrian target to effectively reduce missing rate.
		2017 Vol. 38 (4): 379-382 [Abstract] ( 894 ) [HTML 1KB] [ PDF 2104KB] ( 1683 )

	383	Body height control of vehicles with laterally interconnected air suspension system under pavement disturbance
		JIANG Hong-1, ZHOU Yang-Yang-1, WANG Yu-Jie-1, LI Mei-2
		Taking the laterally interconnected air suspension as research object, the height adjustment system in accordance with laterally interconnected air suspension was designed, and the mathematic model under pavement disturbance was built. The height adjustment fuzzy control was designed based on the traditional height control target, and the result was verified by the bench test. Because the measured height signal with noise interference under pavement disturbance as the input could disturb system to judge, the air mass corresponding to air spring target height was determined as control objective, and the pervious fuzzy controller input and control rules were modified. The stepwise height strategy was adopted to prevent instability phenomenon during height adjustment process, and the actual control performance was verified by simulation in Matlab／Simulink. The simulation results show that the control strategy can adjust body height quickly under the incentive disturbance while the root mean square of sprung mass acceleration has no deterioration during height adjusting comparing to initial height. The suspension damping performance is retained to well keep the body posture stable.
		2017 Vol. 38 (4): 383-388 [Abstract] ( 933 ) [HTML 1KB] [ PDF 2982KB] ( 1533 )

	389	Experiment on premixed laminar combustion of n-butanol
		PAN Suo-Zhu-1,2, QIAN Yun-Shou-2, HAN Wei-Qiang-1,2, HAN Zhi-Qiang-1,2, XIA Qi-3
		Based on the constant volume combustion bomb, the effects of equivalence ratio (0.7～1.6), initial temperature (400, 430 and 460 K) and initial pressure (0.1, 0.2 and 0.3 MPa) on butanol-air premixed laminar combustion were investigated by the ball type flame extension method with high speed schlieren photography technology. Several key parameters of laminar combustion of laminar combustion velocity, flame propagation velocity and stretch rate were analyzed in detail. The results show that the stability of flame front becomes worse with the increasing of fuel-air equivalence ratio, while the flame propagation velocity and the laminar burning velocity of unstretched flame are increased firstly with latter decreaseing. Both the flame propagation velocity and the unstretched laminar burning velocity are increased with the increasing of initial temperature, while the stability of flame front is decreased. The unstretched laminar burning velocity and the flame propagation velocity are decreased with the increasing of initial pressure, and the stability of flame front is deteriorated. In addition, the elongation of flame front surface is decreased with the increasing of flame propagation velocity.
		2017 Vol. 38 (4): 389-395 [Abstract] ( 910 ) [HTML 1KB] [ PDF 2626KB] ( 1927 )

	396	Effects of additional lift curve on intake state of diesel engine with variable valve
		TIAN Wei-1, HE Wen-Xiao-1, HAN Zhi-Qiang-1, HAN Wei-Qiang-1, GUO Ming-Qiang-1, XIA Qi-2
		Based on the independently developed variable valve system of DK4A diesel engine, the effects of additional valve lift, duration of additional valve lift and intervals between additional valve lift peak and original valve lift peak on intake air state parameters were investigated by simulation and experiment. The results show that there is critical value of intervals between additional valve lift peak and original valve lift peak. If the interval is less than the critical value, the interval has no effect on in-cylinder air state parameters of engine. When the interval is larger than the critical value, the closing timing of intake valve is retarded with the increasing of interval, and the intake manifold air flow, the in-cylinder temperature and the in-cylinder pressure at the top dead center are decreased. Under the condition that the additional valve lift does not influence the closing timing, the change rate of in-cylinder air state parameters is increased with the increasing of additional valve lift. Under the condition that the additional valve lift has effect on the closing timing, the intake valve closing timing is retarded, and the intake air flow, the temperature and pressure at top dead center are decreased with the increasing of additional valve lift duration.
		2017 Vol. 38 (4): 396-402 [Abstract] ( 1226 ) [HTML 1KB] [ PDF 3133KB] ( 1514 )

	403	Comparative analysis of subjective and objective evaluation models of interior sound quality
		ZUO Yan-Yan, ZHANG Hai-Feng, ZHUANG Ting
		In order to study the relatively ideal subjective and objective evaluation models of car interior sound quality, the diver binaural noise samples were collected at the speed of 60 km?h-1 while different music was played inside the car. The samples were pretreated with edit, equal loudness and frequency segmentation filtering. Subjective evaluation test of interior sound quality and objective parameter calculation were conducted based on paired comparison method. Three subjective and objective evaluation models of multiple linear regression model, BP neural network model and radial basis function (RBF) model were established. The prediction effects of three models were compared. The results show that every frequency segment has large error in multiple linear regression model with poor stability, which proves that the evaluation of interior sound quality is nonlinear process. The error of overall sample is the lowest in BP neural network model except frequency from 160 to 1 280 Hz, which is lower than that of multiple linear regression model but with a quite gap from ideal error. The error can be controlled within 20％ in the RBF model with good stability. The RBF model has fine prediction performance for interior sound quality under the test condition.
		2017 Vol. 38 (4): 403-409 [Abstract] ( 800 ) [HTML 1KB] [ PDF 1558KB] ( 1672 )

	410	Influence of interconnected air suspension on vehicle vibration performance
		ZHANG Yun-1, ZHOU Kong-Kang-1, QIAN Kuan-2
		Taking the interconnected air suspension as research object, the acceleration frequency responses under different interconnected modes were investigated by building a vehicle test bench. Based on vehicle dynamics, thermodynamics and fluid mechanics, the full vehicle model with interconnected air suspension was established and simulated with integrating non-interconnection, lateral interconnection, longitudinal interconnection and four-corner interconnection. The effects of four interconnected modes on bounce, pitch and roll frequency were analyzed. The acceleration responses of vehicle at 60 km?h-1 on level C pavement were investigated in both frequency and time domain. The results show that compared with non-interconnection, the RMS of spring mass acceleration of interconnected air suspension in 0.5～7.0 Hz is improved under twisted sine excitation, and the roll frequency is reduced by lateral and four-corner interconnection. The pitch frequency is reduced by longitudinal and four-corner interconnection, and the ride comfort in three interconnected modes is improved on the random road.
		2017 Vol. 38 (4): 410-415 [Abstract] ( 1344 ) [HTML 1KB] [ PDF 2504KB] ( 1499 )

	416	Visualization and numerical simulation of hydrodynamic cavitation in single hole orifice plate
		HE Zhi-Xia-1,2, ZHANG Xin-1, CHEN Yu-Hang-1, JI Chang-Hao-1
		As a simple hydrodynamic device,the single hole orifice plate was used to intensify liquid-liquid heterogeneous macromixing for preparing biodiesel or emulsified diesel.A flow visualization experiment system was set up with transparent hydrodynamic cavitation reactor to investigate the cavitation in the orifice plate and the outlet of the orifice plate.A high resolution and speed CCD equipped with long distance microscope device was used to acquire flow images of different ambient pressures. The effects of back pressure and cavitation number on the change of hydrodynamic cavitation were investigated.The results show that the cavitation inception hysteresis phenomenon is observed for fixed back pressure.When the back pressure reaches certain level, the flowing loss at high back pressure is smaller than that at low back pressure. Some cavity bubbles merge into large-scale bubbles and exist in the downstream region of orifice plate to cause choking flow. The cavitation in orifice plate has great impact on the outlet of orifice plate. Compared the numerical simulation results with the experimental results measured by high speed camera,it is found that LES model can well predict the cloud cavitation and the re-entrant jet which is central to the process of cloud cavitation shedding.With the development and collapse of cloud cavitation,the length of cavity changes periodically.
		2017 Vol. 38 (4): 416-422 [Abstract] ( 1072 ) [HTML 1KB] [ PDF 4150KB] ( 1579 )

	423	Design and experimental analysis of side-shift row-follow control system
		ZHANG Jun-Xiong, WANG Kai, ZHANG Liang, SUN Zhe, ZHANG Chun-Long
		To enhance the speed of agricultural machinery operation and the ability of precision operation and realize row-follow control system, the side-shift row-follow system was developed based on machine vision and hydraulic servo control technology. The developed device could carry different machines to complete different functions. In the whole process, the visual information of crop rows was collected by a PC in real time and transmitted to a slave computer. Based on the information, the core of lower computer processor MC9S12DG128 controlled the movement of device precisely,and the vehicle speed was collected in real time to realize line precision. Not only the tractor steering operation and the frequency on crop ridge damage were reduced, but also the damage to crops was reduced to ensure the normal growth of crops. The mechanism position information was displayed on a monitor to guide drivers to track on rows. The test results show that compared with that without line device, when the speeds of tractor are 0.58, 1.22, 2.19 km?h-1, the accuracies of row-follow with line device are increased by 27.9％, 29.1％, 31.7％,respectively.
		2017 Vol. 38 (4): 423-427 [Abstract] ( 934 ) [HTML 1KB] [ PDF 1954KB] ( 1822 )

	428	Experiment on silage baling efficiency and power consumption of Chain-crossbar round baler
		GAO Dong-Ming-1, LI Jie-1, WANG De-Cheng-2
		The baling power consumption and efficiency were investigated by torque sensors, data acquisition and computer equipment. The effects of machine settings, material conditions and operating parameters at different levels on baling power and efficiency were discussed. The results show that the power consumption time-domain curve can be divided into three types for green fodder with 3～5 cm cutting length. The first type is characterized by stepwise mutation instantaneous power. The second type is characterized by gentle slope unimodal curve with relatively short baling time,and the third type is characterized by gentle slope multimodal with long baling time. The feeding pressure angle is the biggest affecting factor on baling energy consumption and working efficiency. Choosing alfalfa or corn stalks as baling material almost has no effects on energy consumption and working efficiency. Under the conditions of 15° pressure angle, 60％ moisture content and 1.9 m?s-1 line speed of Chain-crossbar, the machine can consume the lowest energy to achieve the maximum baling efficiency in smooth working process.
		2017 Vol. 38 (4): 428-433 [Abstract] ( 936 ) [HTML 1KB] [ PDF 1477KB] ( 1262 )

	434	Numerical simulation of working fluid effects on two-phase flow in LMMHD power generation system
		LI Wei-1, LU Peng-1, ZHENG Xing-Wen-1, HUANG Hu-Lin-2
		To improve the transport rate of two-phase flow with low-boiling point working medium and liquid metal in liquid metal magneto hydro dynamic (LMMHD) system, the numerical simulation was carried out to choose working fluid. The low-boiling point working mediums of trifluoro-trichloro-ethane and chloroform and the liquid metal of tin and gallium were selected respectively, and the physical process of the liquid metal with low-boiling point working medium vapor was numerically studied by CFD simulation software. Based on the simulation results and theoretical analysis, the effects of working fluid type on the transport characteristics of gas-liquid two-phase flow were discussed. The results show that under the condition of liquid metal without intrusion, the low boiling point working medium with low molecular weight, small latent heat, small heat capacity and high density and the liquid metal with high density, large heat capacity and high heat conductivity are more conducive to transport gas-liquid two-phase flow. The boiling point of low-boiling point working medium and the melting point of liquid metal should be chosen according to the application objects.
		2017 Vol. 38 (4): 434-439 [Abstract] ( 1179 ) [HTML 1KB] [ PDF 1421KB] ( 1641 )

	440	Fluid field calculation and temperature rise optimization of inner wind path for medium-size high-voltage asynchronous motor
		WEN Jia-Bin-1, LIU Yan-Cui-1, LI Ying-Nan-2
		To investigate the effects of duct number in motor on inner wind path flow and temperature rise, the YKK450-4 of 500 kW medium high-voltage asynchronous motor was taken as example. According to the actual scale, the flow field of inner wind path and the winding end region of stator were simulated to achieve the physical actual model of fluid-solid coupling. Based on the calculation of flow field of the stator, the flux and the flow velocity at each entrance of rotor bracket of ventilator were obtained. The calculation of motor stator was conducted by piecewise fluid-solid coupling method to obtain the highest temperature rise region. According to the hottest position by numerical calculation, a temperature sensor was embedded in the prototype to conduct temperature rise experiment. The results were compared to verify the physical model and solving method. Under the condition that the motor shell size remains unchanged, the width of ducts was changed to reconstruct model for discussing the effects of duct number on fluid flow and heat transmission in motor ducts, and the hottest position for different duct numbers was calculated. The results show that when 9 equal width ducts are adopted, the maximum fluid velocity in motor ducts is obtained. The motor temperature rise is 104.9 K, and the highest temperature rise is decreased by 11.2 K than that under the condition for 10 ducts with the highest temperature rise of 116.1 K.
		2017 Vol. 38 (4): 440-448 [Abstract] ( 1229 ) [HTML 1KB] [ PDF 6942KB] ( 1470 )

	449	Brain tumor extraction based on spatial-feature combining kernel sparse representation
		LIU Ding-Yi-1, LIU Ya-Jun-2, ZHAN Tian-Ming-3
		To improve the brain tumor extraction accuracy by multisequence MR image, the spatial-feature combining kernel sparse representation (KSR) was proposed to connect spatial structure information and intensity feature information for brain tumor extraction. The sub-dictionary of each label was built， and the neighboring filtering kernel based on KSR was applied to extract brain tumor from MSMR images. The spatial information and the intensity feature information were combined in the proposed method to improve the accuracy of brain tumor extraction. The clinical and simulation data from MICCAI BraTS dataset were divided by the proposed method. The results show that compared with sparse representation method, the proposed brain tumor extraction method based on spatial-feature kernel sparse representation can increase the brain tumor extraction accuracy by 5％～6％ due to the introducing of spatial structure information.
		2017 Vol. 38 (4): 449-454 [Abstract] ( 777 ) [HTML 1KB] [ PDF 1724KB] ( 1377 )

	455	Paradigm of artificial intelligence in big data era
		CHENG Xian-Yi-1,2, HU Hai-Tao-2, QU Ping-3, CHENG Shi-1,2
		To solve the problems of high cost for knowledge acquisition with poor quality and only simulating low-level intelligence in traditional artificial intelligence paradigm, inspired by the full sample statistic in big data, the approximate searching and the related reasoning, 4 AI paradigms were proposed with perception, data, brain science and cognition as center, respectively. The AI paradigm with perception as center was used to study the distributed and loosely coupled main body to use knowledge, skill and information in coordination and achieve the respective or global goal or plan. The data-centric AI paradigm was formed from quantitative change to qualitative change data, and the core was the data. The AI paradigm with brain science as center was used to make comprehensive research platform based on information and communication technologies. The research purpose of AI paradigm with cognition as center was to use big data to solve the problem of "mind". The paradigm determines the way to realize the AI, and different paradigms have their own characteristics and complement each other. Any one paradigm can't be unified in one format, and the AI paradigm is attributed to 4 paradigms of scientific research.
		2017 Vol. 38 (4): 455-460 [Abstract] ( 1452 ) [HTML 1KB] [ PDF 1344KB] ( 2386 )

	461	Preparation and performance of self-healing epoxy resin matrix composites using microcapsules
		YUAN Xin-Hua, CHEN Yan-Qiu, ZHANG Qian, LIU Yong-Qiang
		The self-healing epoxy resin microcapsules were synthesized by in-situ polymerization with urea-formaldehyde resin as shell material and E-51 epoxy resin as core material. The morphology of microcapsules was observed by scanning electron microscope(SEM), and the size and distribution were measured by metallurgical microscopy. The chemical structure of microcapsules was characterized by Fourier transform infrared spectroscope(FTIR), and the thermal degradation characteristics were determined by thermogravimeter (TGA). Microencapsulated E-51 epoxy resin healing agent and phthalic anhydride latent curing agent were embedded into E-44 epoxy matrix to prepare self-healing epoxy composites. The impact strength and the self-healing efficiency of composites were measured by Charpy impact tester. The results show that the microcapsules are uniform sphere with high core content and good thermal stability. The fracture of pure epoxy shows brittle performance with mirror fracture surface, while the fracture of composites with microcapsules exhibits hackle marking. In the case of 8.0％ microcapsules and 3.0％ latent hardener, the optimum self-healing efficiency reaches 81.5％.
		2017 Vol. 38 (4): 461-465 [Abstract] ( 1091 ) [HTML 1KB] [ PDF 3047KB] ( 1987 )

	466	Neural network method in bridge condition assessment by B-TBU model
		WU Duo-1, LIU Lai-Jun-1, MIAO Ru-Song-2
		The present commonly-used bridge condition assessment methods were easily influenced by human subjectivity and arbitrariness, and the impact of historical evaluation data on the current state was also neglected by these methods. To solve the problem that the current true state of bridges could not be accurately reflected, the B-TBU model method was proposed based on Bayesian inference characteristics of taking prior information influence into account. The influence of historical evaluation data on the assessment of current state was considered, and the bridge state over the past twenty years was reevaluated. The evaluation results show that the state evaluation accuracy can be significantly improved with the bridge annual state evaluation accuracy increased above 90％. The BP neural network and the ELM neural network were preliminarily introduced into B-TBU model to train B-TBU model. The results show that high evaluation accuracy can be achieved via the neural network method with the annual state evaluation accuracy of about 80％.
		2017 Vol. 38 (4): 466-471 [Abstract] ( 826 ) [HTML 1KB] [ PDF 2062KB] ( 1408 )

	472	Analysis on nonlinear consolidation of structural soft soil by considering non-Darcian flow
		LI Chuan-Xun, WANG Chang-Jian, WANG Su, DONG Xing-Quan
		Based on Terzaghi′s theory of consolidation and classical Hansbo′s non-Darcian flow model, a nonlinear consolidation model was developed with consideration of natural soil structure and time-dependent load in practical engineering, and the finite difference method was adopted to obtain numerical solutions of the model. Based on the reliability of numerical solutions, the effects of non-Darcian flow and soil structure on the consolidation behavior of structural soft soil with non-Darcian flow were analyzed. The results show that the consolidation rate of structural soft soil with non-Darcian flow is slower than that with Darcy′s flow. The consolidation rate is decreased with the increasing of m or i1 value. When the non-Darcian flow in structural soft soil layer is considered, the consolidation rate is increased with the increasing of structural yield stress and decreasing of compression-index below structural yield stress. The final settlement is decreased with the increasing of structural yield stress and decreasing of compression-index below structural yield stress.
		2017 Vol. 38 (4): 472-478 [Abstract] ( 681 ) [HTML 1KB] [ PDF 2483KB] ( 1352 )

	479	High temperature performance of chemical modified asphalt based on repeated creep and recovery test
		CHEN Zhi-Jun, HAO Pei-Wen
		In order to explore the high temperature rheological properties of PPA and RET modified asphalt binders, the viscoelastic response law of base asphalt, PPA modified asphalt, RET modified asphalt and SBS modified asphalt under different load stresses and temperatures were investigated based on the repeated creep and recovery test. The delayed elastic behaviors of asphalt binders were analyzed from temperature and stress. The properties of PPA and RET asphalt binders were compared with those of SBS modified asphalt binder to objectively evaluate the high temperature performance of the two kinds of chemical modified asphalt binders. The Burgers model was adopted to fit the experimental data. The relevant relationship between viscous composition in creep stiffness and dynamic stability of asphalt mixture was analyzed. The results show that the addition of PPA and RET can significantly improve the deformation resistance of asphalt at high temperature to enhance the anti-rutting performance of asphalt pavement.
		2017 Vol. 38 (4): 479-483 [Abstract] ( 1134 ) [HTML 1KB] [ PDF 1879KB] ( 1866 )

	484	Technical performance of RET modified asphalt mixture with polyester fiber
		CHANG Rui, HAO Pei-Wen
		To investigate the effects of polyester fiber and RET on the performance of asphalt mixture, high temperature stability, low temperature crack resistance and anti-fatigue performance of RET modified asphalt mixture with polyester fiber were evaluated through penetration shear test, semi-circular bending test and bending fatigue test. Penetration shear strength,fracture energy density and fatigue life were compared with those of SBS and SBR modified asphalt mixture. The fatigue properties of different asphalt mixtures were analyzed by Weibull distribution under different failure probabilities. The results show that compared with SBS and SBR modified asphalt mixture, the penetration shear strength, the fracture energy density and the fatigue life of composite modified asphalt mixture are increased significantly. RET and polyester fiber can significantly improve high temperature stability of asphalt mixture, and the low temperature performance of RET modified asphalt mixture can be effectively improved. The polyester fiber composite RET has significant effect on the fatigue property of asphalt mixture.
		2017 Vol. 38 (4): 484-490 [Abstract] ( 870 ) [HTML 1KB] [ PDF 1492KB] ( 1460 )

	491	Pavement performance of composite process rubber asphalt mixture
		LI Wei-1, HAN Sen-1, WU Sheng-Hai-2, SUN Pei-1, NIU Dong-Yu-3
		To investigate the technical indexes of composite process rubber asphalt and the mixture road performance, appropriate dosage of cleavage agent was added in the process of preparing mixture, and the reasonable processing temperature and time were determined. Based on the tests of water stability, low temperature bending and fatigue properties, the durabilities of 4 kinds of composite process rubber asphalt mixtures were determined. The test results show that when the dosage of cleavage agent is 0.4％, the appropriate processing conditions of rubber modified asphalt are at 190 ℃ for 2 hours. With the addition of cleavage agent, rubber asphalt mixture has excellent high temperature property, low temperature property and anti-water damage property, and the dynamic stability is about 3 times as much as that of asphalt mixture. The rubber asphalt mixture by composite process has excellent anti-water damage property, fatigue resistance and low-temperature bending performance, and the flexural tensile failure strain is even higher than that of rubber particle SBS modified asphalt mixture.
		2017 Vol. 38 (4): 491-496 [Abstract] ( 874 ) [HTML 1KB] [ PDF 1327KB] ( 1474 )

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