Abstract:For hydrogen production in vehicle dimethyl ether (DME) steam reforming reaction system, the thermodynamic efficiency of reforming reaction system was analyzed. The change of chemical equilibrium constant in main reactions with temperature was confirmed. The effects of steam-to-DME ratio, temperature and pressure on equilibrium were studied. The results indicated that DME reformed gas increased low heat value by 15.45％. DME had a high conversion when the temperature was higher than 473K and steam-to-DME ratio was more than 2, and the equilibrium concentration was close to zero. The main components of reformed gas were H2, CO and CO2. The content of H2 showed the most, and the largest concentration was 72%. With high temperature and low steam-to-DME, carbon in DME would be converted to CO. With low temperature and high steam-to-DME, carbon in DME would be converted to CO2. Pressure had little effect on the reaction equilibrium concentration.

Abstract:The onboard fuel reforming could not only recovery the exhaust heat but also produce syngas for the mixed combustion in cylinders. An experimental study was carried out on a four-cylinder 1.6L gasoline engine at a speed of 1800r/min, a manifolds absolute pressure of 61.5kPa and the maximum brake torque for the spark timing to explore the effect of syngas addition on the engine combustion and emission performances at the stoichiometric condition. The experimental results demonstrated that the hydrogen volume faction in syngas increased with the increase of syngas addition faction. The fuel consumption rate was decreased and the indicated thermal efficiency was improved. HC, NOx and CO2 emissions were reduced whereas CO emission was increased after the syngas enrichment at the stoichiometric condition.

Abstract:The response performance of electr-hydraulic VVT technology has significant influence on combustion and emission of gasoline engine. Actual valve timing value should be quickly adjusted to target value on transient operation conditions for gasoline engine. Response speed of electro-hydraulic VVT can be further improved since it has constraints for breakthrough. Factors which have influence on the response speed of electr-hydraulic VVT were studied by both experiment and simulation. Step response process was divided into several sub-process and analyzed. Feed forward control algorithm was designed and applied in VVT control. Experiment results showed that the proposed method could achieve rapid response of VVT and assure the stability at the same time.

Abstract:An image processing program with good instantaneity for gasoline direct injection spray based on Matlab/GUI was designed and the program realized visual operation interface. As gasoline is fuel with great volatile, the spray boundary of GDI image is relative obscure and SNR of the spray image is not satisfied compared with that in diesel injection. To get the accurate spray penetration, cone angle, perimeter, area and other needed parameters, the spray boundary was precisely extracted in the image processing. Noise filtering, boundary detection，morphological analysis and other related methods have been used. After the spray boundary was obtained, program to calculate spray penetration, cone angle, injection velocity and other parameters was developed to realize real-time measurement of spray parameters.

Abstract:The flame characteristics of biodiesel burning in industrial furnace were studied. The volume, shape, structure of flame and length were analyzed based on image processing by using high-speed photography method. The experimental results showed that with the increase of excess air coefficient α, the volume of flame gradually decreased and the flame deformation was more and more serious. With the increase of atomization pressure p, the volume of flame first increased and then decreased. The flame deformation was more and more serious, and the flame structure was more and more fragmented. Through the calculation, the range of the actual length of the flame of 0.2s was very large, which emerged a sudden increase and drop rule, existed a “taking off the flame” process. The flame length became inversed to the excess air coefficient α. Along with the decrease of the atomization pressure p, the curve of flame length changed gently.

Abstract:Effect of CO2 dilution on combustion and emission characteristics of CH4, H2 and CO was analyzed in a spark-ignition engine. The results showed that dilution could reduce NOx emission. Suitable dilution ratio had little influence on brake mean effective pressure, cyclical fluctuation and brake thermal efficiency. However, excessive dilution ratio would induce to partial burn. Favorable operation range of biogas could be obtained with acceptable brake thermal efficiency and NOx emission by employing dilution combustion, which benefits for biogas application.

Abstract:In the large flow conditions, the double suction centrifugal pump is susceptible to cavitation damage and has bad operation reliability. Aiming at the problem, a compound impeller with long and short blades was used to improve the cavitation characteristics. By using the shear stress transport (SST) k—ωturbulence model and Rayleigh—Plesset cavitation model, numerical simulation of the double suction centrifugal pump with a conventional impeller and a compound impeller were carried out respectively. The simulation results in the form of characteristic curves were compared with the experimental data, and the internal flow field was analyzed. The result showed that in the large flow conditions, critical net positive suction of the pump with a compound impeller was reduced. Also, the compound impeller can reduce the vapour distribution, change the pressure distribution and improve the dropping flow and backflow. Moreover, the better effect would be achieved under large flow condition.

Abstract:In order to optimize the matching of impeller with extra-thick blades and volute in centrifugal pump, the structure displacement and velocity of different volutes were simulated by two-way coupling fluid-structure interaction method. The numerical results showed that volute was influenced by alternately exciting force due to the flow field interaction between the impeller and the tongue, and vibration displacement and vibration velocity distribution changed cyclically at different time steps. The ratio of volute base circle diameter and impeller diameter D3/D2 had a significant impact on volute vibration. When D3/D2 was less than 1.013, the un-uniform velocity distribution induced by jet-wake in blade outlet leaded to the strong pressure pulsation and vibration of volute. However, the peak-to-peak value of the pressure pulsation was reduced and the vibration of the volute was weakened when the ratio D3/D2 gradually increased. In the design conditions, maximum vibration displacement in case A (D3/D2=1.013) was 4.288×10-6m, and the maximum vibration speed was 8.547×10-4m/s. In case C (D3/D2=1.19) was 2.923×10-6m and 5.253×10-4m/s respectively. The optimized case B (D3/D2=1.13) had the minimal vibration with the maximum displacement of 2.56×10-6m and the maximum vibration speed value of 4.823×10-4m/s. The results also demonstrated the direct relevance between the radial force law and volute vibration characteristics in centrifugal pump.

Abstract:In order to analyze the effects of specific speed ns of impeller pumps on hydraulic performance theoretically, relative head-flow equation and shaft powe-flow equation were deduced under the ideal fluid condition based on the basic equation of impeller pumps. The relations between the equations and ns were analyzed as well as the equations application. The results showed that the equations of relative characteristic curves of impeller pumps were functional set of high efficient operation relevant to ns and the slope of iso-efficiency curve (IeC) passing the nominal operation point (NOP). The characteristic curve describing the relation of relative head to relative capacity (RC) was the quadratic parabola of ns and the curve describing the relation of relative shaft power to RC is the cubic parabola of ns; for the RC unequal 1, pump efficiency is decreasing with increased ns. A high ns causes gentle slope of IeC passing NOP, consequent on the high efficient operation range of impeller pump approaching the capacity axis in the comprehensive characteristic curves charts; conversely, the high efficient operation range approaching the head axis for a low ns.

Abstract:The inner flow of fluidic component with small offset ratio was measured by using particle image velocimetry (PIV). The velocity distribution of fluidic component and position of attachment point were obtained to provide reference for the numerical simulation in the future. The effects of flow rate, offset ratio, distance of air entrance hole, and cover size on the inner flow of fluidic component were analyzed and compared with numerical results. The results showed that in a certain range, the flow rate and working pressure had no effect on the distance of attachment point. The attachment point ratio increased with the increasing offset ratio. The relation equation of attachment point ratio and offset ratio was found. The distance of attachment point became shorter firstly then longer with the increasing distance of air entrance hole. The offset ratio and cover size were sensitive to offset jet flow.

Abstract:The variation of heavy metal content in soils has important influence on cultivation security of crops. The concentrations of Pb, Hg, Cd, Cr, Cu and similar heavy metal As in arable soil were quarterly recorded in Binzhou of Shandong during the period from January 2010 to January 2013. The methods of periodic analysis and fast Fourier transform (FFT) spectral analysis were applied to calculate the principal component cycle of heavy metals, and to make further periodic test. The results showed that there was a different degree of accumulation trends in metals between the periods. The principal component cycle of Pb was two quarters in a year, Cd and As had four quarters as the main component cycle, and other heavy metals major cycle characteristics was not obvious.

Abstract:Based on field capacity test with different soil structures, soil texture and organic matter content, the dominant factors impacting the soil field capacity were analyzed. With the multiple linear regression model, multiple non-linear regression model and BP model method, the different transfer functions between field capacity and soil physical and chemical properties were set. The result showed that these conventional physical and chemical performance parameters of soils, including dry density, silt content and clay content of soil structure, soil texture and soil organic matter content, all had significant impact on field-water capacity. It was feasible to forecast field specific retention by the different transfer functions, which had higher prediction accuracy (relative error less than 10%) and BP model was the best (relative error was 3.24%).

Abstract:According to the experiment and numerical simulation, a multi-objective optimization model for identification of solute and water transport parameters was built up, which use soil water content and the minimum standard deviation of measured and observed water content and solute as optimized objective. A combination of genetic algorithm, finite difference and linear weighted method was applied for calculation. Taking one, two and three groups experimental data as initial data, solute transport parameters in unsaturated soil were obtained and verified by using the experimental data at 1345min. The maximum and minimum correlation coefficient between calculated and measured value of water content were 0.9753 and 0.9450. The maximum and minimum correlation coefficient between calculated and measured value of bromonium ion concentration was 0.9646 and 0.9352. The measured results were well coincided with the calculated results and showed the feasibility of the proposed method.

Abstract:The validities of Denitrification—Decomposition (DNDC) model and the simulation parameters were examined by using field experiment data obtained from a wheat/maize rotation system. Based on the differences between N availabilities in reclaimed water and inorganic N fertilizer, three scenarios (1∶1, 1.7∶1, 2∶1) were hypothesized to evaluate the feasibility about simulating nitrous oxide (N2O) emission in soil irrigated with reclaimed water by DNDC model. The results showed that DNDC model performed well in verifying the temporal variations of soil moisture under reclaimed water (r=0.716, n=29, P<0.01) and ground water irrigation (r=0.703, n=29, P<0.01), and mean daily temperature (r=0.89, n=35, P<0.01) at soil surface under ground water irrigation. The peaks of N2O induced by irrigation, rainfall and fertilization events were detected by DNDC model. However, the measured N2O fluxes generally lagged behind the simulated fluxes, so the performance of DNDC model were not satisfied in simulating N2O fluxes. The measured and estimated N2O production was 1.84kg/hm2 and 1.83kg/hm2 under scenario 1.7∶1, indicating that N in reclaimed water had higher availability than that in fertilizer, and DNDC performed well for evaluating cumulative N2O emissions on short-term reclaimed water irrigation.

Abstract:The potential effects of sediment load (S) on hydrodynamic parameters of overland flow were investigated in a smooth plexi-glass flume under a wider range of sediment load and slope gradient of 9°. The results showed that Reynolds number (Re) decreased as sediment load increased, implying a decrease in flow turbulence. Froude number, mean flow velocity and correction factor to flow velocity (α) first all decreased with sediment load increasing and then the values all suddenly increased and gradually become stable as sediment load further increased when S>300kg/m3. The mean α was 0.554. For the difference between standard of energy dissipation in sediment-laden and clear-water overland flow, the conclusions were also different. When S<300kg/m3, the friction coefficient of sediment-laden flow was larger than that of clear water flow either with the same Reynolds number or unit flow rate as standard. While, when S>300kg/m3, the friction coefficient of sediment-laden flow was smaller than that of clear water flow with the same Reynolds number and larger with the same unit flow rate.

Abstract:The cohesion and internal friction angle under the different EN—1 contents, curing ages, compaction degrees and water contents treated with EN—1 were determined by using direct shear test. The results showed that the shear strength of Pisha sandstone solidified soil had varying degrees of increase than plain soil with the increase of EN—1 contents and curing ages under the EN—1 contents, curing ages, compaction degrees and water contents in this experiment after EN—1 were added. The shear strength of Pisha sandstone solidified soil was the biggest when EN—1 content was 0.20% and curing age was 30d. The shear strength of Pisha sandstone solidified soil increased with the increase of compaction degree and the decrease of water content after EN—1 was added. Consequently, in order to make the EN—1 solidified soil have favorable shear strength and satisfy engineering demand, it suggested that EN—1 content was 0.20%, curing age was 7~15d, compaction degree was greater than 95%, and water content was slightly less than optimum moisture content when EN—1 was used practically to solid and protect slope in Pisha sandstone region.

Abstract:In order to obtain a simple and reliable method for volatile fatty acid concentration and bicarbonate alkalinity, Nordmann titration method and instrument method were chosen in lab-scale CSTRs for chicken manure. The accuracy was compared and correction of titration method was made. The result showed that the Nordmann titration method and instrument method for VFA and TIC concentration determination were significant difference, and the mean relative error was more than 50%. After correction, the mean relative error was significantly reduced and lower than 10% when the organic load was higher than 4.0g/(L·d). It means that the modified titration method could achieve more simple and accurate determination of VFA and TIC concentration. Also, as the total VFA concentration measured by the modified titration method had a good correlation with the acetic acid concentration measured by gas chromatography, the modified titration method could estimate the acetic acid concentration. Compared to pH value, VFA/TIC ratio measured by modified titration method could realize early warning of acidification.

Abstract:In order to optimize the premixing process of the herbivorous livestock manure and straw for joint photosynthetic microorganisms hydrogen production, the method of Box-Benhnken experimental design and response surface analysis were used with Design-Expert software. The response surface experiments contained three factors, such as pH value, premixed temperature and premixed time. Response value was OD value and zero point experiments proceed three times. The response surface experiment data were analyzed by Design-Expert software, and the results showed that the quadratic model was the most accurate expression. The three factors existed significant correlation. The premixing process was optimized by the amendment of the regression equation: time of 6.3d, the pH value of 4.9, temperature of 48℃, the estimated maximum OD value of 2.6968. The predicted value was closed to the average value of the validation test. The results provided a theoretical basis for the experimental study of photosynthetic microorganism hydrogen production.

Abstract:The reaction course and delignification kinetics of wheat straw pretreated with propionic acid was studied. The results showed that two distinct delignification phases occurred during this pulping process of wheat straw, which were the initial delignification phase from the beginning to 60min and the residual delignification phase from 60min to 180min. The rate constant and the order of reaction were determined through the establishment of kinetic equation in delignification reaction. Under the temperature of 333K,343K,353K,363K, the rate constants were 0.0023, 0.0028, 0.0037 and 0.005. And the reaction order was the first grade. In the range of temperature and time under which the experiment was carried out, the average active energy was 26.05kJ/mol, the frequency constant was 26.797L/(mol·min).

Abstract:The rice husk ash (RHA) from biomass gasifiers was hydrothermally reacted with KOH solution to obtain the RHA ludox, which was used to synthesize K—ZSM—5 zeolite by hydrothermal crystallization. The effect of hydrothermal reaction time on the Si dissolving rate was investigated, and the complex composition of the RHA ludox was analyzed as well. The effects of template types, Si/Al molar ratio, crystallization temperature and time on the nucleation and growth of K—ZSM—5 zeolite in the complex RHA synthesis system were studied. The as-synthesized samples were characterized by XRD, SEM, ICP, TG, N2 adsorption-desorption and other means. The results showed that the structural directing agents with strong template effect were necessary to synthesize K—ZSM—5 zeolite directly using the RHA ludox. The zeolite crystals could not be prepared by the weak organic template as ethanol, however, using little TPABr strong template, the K—ZSM—5 zeolite crystals could be synthesized with a certain range of the Si/Al molar ratio. But there were some disadvantages such as the narrow adjustable range of synthesis solution, irregular crystal shape, large grain size, high synthesis temperature, long reaction time, and so on. It was also found that the calcination methods had great influence on the pore structure of large K—ZSM—5 products. It was easy to form deposited carbon over the zeolite crystals that were directly calcined at 550℃. To obtain pure K—ZSM—5 products, it must be calcined at 350℃ for 3 h before high temperature calcination at 550℃.

Abstract:The CoAPSO-5 membrane on the α-Al2O3 substrate was synthesized by using in situ crystallization. According to detection results of scanning electron microscopy (SEM) and X-ray diffraction (XRD), the 20μm thick membrane was composed of well intergrown CoAPSO-5 crystals, which were tightly covered on the α-Al2O3 substrate in random orientation. The gas permeation measurements revealed the resulting membrane was of high-quality with few non-zealitic pores. In addition, the separation property of CO2/CH4 through the synthesized CoAPSO-5 membrane was investigated. When the osmotic pressure was 0.3MPa and 0.5MPa, the real separation factor of CO2/CH4 was 4.86 and 5.29 respectively.

Abstract:For high hydrostatic pressure (HHP) had a dual role in preserving texture properties, the relationship between the texture of fruit and vegetable products and cell structure were reviewed. On that basis, the mechanism about how high pressure affects the fruit and vegetable texture was clarified from three levels of cell structure. Furthermore, based on the comprehensive analysis of a large body of literature, the research progress of high pressure on the texture of fruit and vegetable products was summarized. At last, the research direction in the field was pointed out so as to provide the ideas on how to improve the texture of fruit and vegetable products.

Abstract:The effects of beaker volume, sample weight and headspace-generation time on the response of a PEN2 electronic nose (e-nose) were studied. Both the peak and final stable responding points of sensors were extracted. Principle component analysis (PCA), linear discriminant analysis (LDA) and analysis of variance (ANOVA) were employed to analyze the responding of each sensor as well as the whole sensor array, and the optimum parameters (500mL beaker volume, 25g sample mass, 5min headspace-generation time) were acquired for later beef storage time detection. The difference in volatile profiles of beef samples of seven different storage times (0, 3, 5, 7, 10, 12 and 14d) was confirmed. The stepwise linear discriminant analysis (Step-LDA) results showed that the correct rate was 98.57%.

Abstract:Based on frequency spectrum of permittivities from 10MHz to 4500MHz of intact postharvest Fuji apples during 21 weeks storage, BP network model and support vector regression (SVR) model were applied to predict SSC. Effects of the prediction models using full frequency (FF), principal component analysis (PCA) and successive projection algorithm (SPA) were compared and evaluated. The results showed that PCA—SVR gave the best result rather than PCA—BP and SPA—BP. The predicted correlation coefficient of PCA—SVR was 0.883 and the root mean square error (RMSE) was 0.552. The effect of PCA—BP was a little worse than PCA-SVR. The RMSE of the model established by SPA was generally smaller than by other methods, and the predicted correlation coefficient of the models established by PCA was generally higher. The research offered some useful technologies in developing nondestructive sensors for fruits’ soluble solids content based on frequency spectrum of dielectric parameters.

Abstract:In order to improve the predictive precision for on-line determination of soluble solids content (SSC) of Gannan navel orange, the dynamic detecting system was applied to optimize online detection model by visible and near-infrared reflectance spectroscopy. The spectra were obtained at the constant velocity of 5 navel oranges per second. After employing various preprocessing methods, the sensitive spectral regions were analyzed by different variable selection methods, including backward interval partial least-squares (BiPLS), genetic algorithm (GA), and competitive adaptive reweighted sampling (CARS). The predictive abilities of the models were evaluated by prediction set. The results indicated that the best model was obtained by CARS with the first derivative. The correlation coefficient (Rp) and root mean square error of prediction (RMSEP) was 0.94 and 0.42% for SSC respectively. The results showed that the proposed method of CARS could effectively simplify the online detection model of SSC of Gannan navel orange based on visible/near-infrared (Vis/NIR) diffuse transmittance spectroscopy, and enhance the predictive precision. The study can provide a reference for optimizing online detecting system of Gannan navel orange.

Abstract:In order to reveal the mechanism of combined convective and infrared radiation in rice drying process and analyze heat and mass transfer characteristics, a mathematical model of combined convective and infrared radiation was established. The heat and mass transfer process in rice drying was simulated. According to the drying conditions in numerical simulation, the test rig of combined convective and infrared radiation was built up to analyze the influence of the drying process under the different operating conditions. The results showed that there was high relativity between the numerical model curves and the experimental curves.

Abstract:For the heterogeneity and random distribution in potato internal structure, the water transport process during drying was simulated by using fractal characteristics. The result showed that the model combined with shrinkage and fractal was more close to the experimental data than no shrinkage and continuum model, and the internal pressure distribution did not fall step by step in proportion as continuous model. The fractal model including shrinkage increased with pore connectivity, porosity, area fractal dimension and the ratio of the minimum and maximum pore diameters, whereas it decreased with tortuosity fractal dimension and pore tortuosity.

Abstract:The kinetics of protein hydrolysis catalyzed by alkaline protease Alcalase 2.4L was investigated in the peanut emulsion medium. The results showed that degree of protein hydrolysis was enhanced with the increase of initial enzyme concentration, but it was decreased with the increase of initial substrate concentration at fixed enzyme concentration. There was a good positive relationship between degree of protein hydrolysis and demulsification of emulsion (r=0.983). The apparent Michaelis constant Km was 0.0698mol/L and the maximum velocity Vmax was 3.71×10-4mol/(min·L) in the peanut emulsion. The kinetic equation of peanut protein hydrolyzed by Alcalase 2.4L at initial stage was obtained based on the experimental data. The critical substrate concentration was 8.73g/L (initial enzyme concentration was 0.05%) for hydrolysis of protein and demulsification.

Abstract:Water-in-oil (W/O) and water-in-oil-in-water (W/O/W) emulsions with bittern solution as internal aqueous phase were prepared. These emulsion coagulants showed good controlled-release property when used in traditional firm tofu preparation. Compared with the traditional bittern coagulant, emulsion coagulants significantly improved the water content from 70% to the maximum 84% or 79%, as well as increased the yield of tofu gel. In addition, the use of emulsion coagulants modified the tofu gel to be more smooth and homogenous, as well as significantly reduced the hardness of tofu gel while remained the spring and improved the bright. Results also indicated that the loss of protein and soy isoflavones during tofu preparation was decreased, along with a higher yield of soy isoflavones.

Abstract:The research achievements of spectral imaging technology in early detection of botanical diseases were briefly summarized. The plant disease is an important factor that restricts the steady development of agriculture. It is fundamental to botanical production and management to utilize real-time, sensitive, stable detection and prevention methods. Combined multi-spectral images, hyperspectral images, infrared thermal images with plant pathology as well as chemometrics, infected plants can be detected in early stage by spectral imaging technology. It is very meaningful to build a quantitative model that can reflect botanical diseases and its extent precisely.

Abstract:A hyperspectral imaging system was developed for detecting various common defects on citrus. Citrus with end rot, insect dot damage, rot damage, thrip scars and normal citrus were chosen. Hyperspectral images of citrus samples and principal component analysis (PCA) were used to confirm two best wavelengths (615nm and 680nm). PC2 of PCA was selected to classify the images. Finally, the detection algorithm combined PCA and band ratio was developed and achieved an accuracy of 94%. The results showed the feasibility of the proposed method.

Abstract:Near infrared spectroscopy (NIRS) technology was applied to discriminate the variety of strawberries rapidly. Compared with seven kinds of preprocessing methods, “SNV+MAF+2D” was ascertained as the optimal scheme. Totally 14 characteristic spectrums related to strawberries information were extracted by the correlation coefficient and threshold value method. Three kinds of correction models of PLS—ANN, PLSR and PCR based on wavelength ranging from 548nm to 562nm were established. Verified by the prediction set samples, the optimal correction model was PLS—ANN with nine principal components. Prediction correlation coefficientand root mean square error of prediction(RMSEP) of the PLS—ANN correction model was 0.9677 and 0.461. The results showed that a few characteristic spectrum extracted to establish PLS—ANN correction model would achieve rapid discrimination of strawberries.

Abstract:To solve the unsupervised segmentation problem of clustering diced-potatoes, a watershed and improved Markov random field (MRF) algorithm was proposed. The original image was easily transformed from pixel based to region based by watershed algorithm, which was good for labeling by MRF. At the same time, the ISING model was improved to make the consistent of probability of MRF. Firstly the original image was transformed from pixel based to region-based by watershed algorithm. Secondly the improved MRF was applied to distinguish over segmentation regions from right segmentation regions by fusing the relative height and area of the original segmentation regions. Finally the most compactness adjoining over segmentation regions were connected into bigger ones. Using this algorithm, 95% of the test clusters were correctly segmented in potatoes preparations.

Abstract:A crop canopy 3-D reconstruction and volume measurement method that based on the ultrasonic sensing technology was proposed. The functions of interp1(), quad and surf in Matlab were introduced for crop canopy description and the volume calculation. Indoor measurements were conducted on six ridges of greenhouse strawberry by 3 times repeats and the results were compared with manual measurement. The result showed the experiments presented good repeatability（R2 was 0.9275, RMSE was 0.1358m3), which showed consistent with the manual measurement (R2 is 0.9411, RMSE was 0.1345m3). Therefore, the proposed measuring system was stabilized and feasible.

Abstract:According to color distribution characteristics of Hlyphantria cunea larva nets, RGB color space was selected and the data differences of each channel were analyzed for net curtains, leaves and branches. Furthermore, R—B color model with the Otsu method and threshold algorithm were used to segment images. The region labeling and Freeman coding methods were adopted to calculate the area of each region. The double threshold value was determined and residual noise was removed by using the mean and standard deviation of a plurality area. According to the differences between area sizes, fine white and white regions were compensated by using improved expansion corrosion method. Experimental results showed that the accuracy of net curtain image recognition was above 85% and single image processing time was less than 40ms.

Abstract:The goal of this study was to develop a method based on Android OS mobile phone by using image processing to rapidly and non-destructively determine leaf area (LA). Software using Java language was used to estimate LA. The steps for processing each image were as follows: image collection, image segmentation, image binarazition, filtering and LA calculation. The proposed method was carried out on triangle of 100mm2, square of 100mm2, circle of 314.15mm2 and five-pointed star of 112.26mm2 in eight distance ranges by AutoCAD precision drawings. The test result showed that the measured error was in the range of -0.62% to 0.79%. The proposed method was applied to measure different leaves representing varied shapes and sizes, such as tomato, eggplant and maple representing. The measured error was within ±1% compared with type LI—3100 leaf measuring device when the distance between mobile and leaf was 300～600mm. The picture sizes were 2560 pixels×1920 pixels and the measuring accuracy was 0.001cm2 in this work, which showed the proposed method could measure leaf areas accurately.

Abstract:The traditional support vector machine has two faults: low classification accuracy and poor timeliness. In order to obtain support vector machine (SVM) with high accuracy and efficiency, the parameter optimization of SVM with mixed kernels based on mutative scale chaos particle swarm optimization (MSCPSO) was presented. This model was used to predict the growth stage of lettuce leave, which was consist of seedling stage, tillering stage and mature stage, and N content levels of three growth periods respectively. The prediction accuracy achieved to 91.51%, 85.38%, 82.59% and 81.26%. Compared with the traditional particle swarm optimization mixed nuclear SVM classifier and mutative scale chaos particle swarm optimization RBF_SVM classifier, the proposed classifier model showed higher classification accuracy and timeliness.

Abstract:In order to detect the wheat biomass non-destructively and fast, a system based on LabVIEW was developed according to the mechanical property of wheat stalk. Real-time acquisition, display and storage of the data was finished by detection system based on LabVIEW, with mechanical sensor as measuring element and collecting resilience signal produced when the stalk was pushed by the rod with high-speed acquisition module DAM—3056AH of ART-TECH. The detection system was tested in the wheat field to examine its property. The results showed that the resilience of the wheat stalks between different varieties were clearly different. The resilience of the wheat stalk had close relationship with biomass (fresh weight), of which the R2 was achieved 0.7127. It was indicated that the detection of wheat biomass based on mechanics was feasible.

Abstract:The LiDAR point cloud and a survey of seven plots Larix olgensis plantation in Changbai Mountain area of Heilongjiang were utilized as the experimental data. A method combined crow height model and 3-D point cloud segmentation was used to identify individual tree. The forest parameters and aboveground biomass based were estimated by using stepwise regression analysis. Experimental results showed that the forest parameters estimated by LiDAR had good correlation with field data. The coefficient of determination between prediction values and observed values of the tree height, crown diameter, DBH and aboveground biomass were 0.8732, 0.6335, 0.7903 and 0.7992, respectively. The average fitting accuracy was 88.34%, 83.46%, 85.11% and 86.19%, respectively. The average biomass of young, half mature, near mature and mature Larix olgensis were 25.12, 94.08, 117.74 and 279.33kg, respectively.

Abstract:An innovative area is forming rapidly with the application of LED (light emitting diode) light sources in the intensive production of poultry which has a highly developed visual system. Firstly, the article reviewed the advancement on LED light environment control technology for intensive poultry production. For broilers, the optimization of LED light color, intensity and photoperiod could improve the structure of small intestinal mucosal and consequently enhance the feed utilization and growth rate. The light environment could also affect the satellite cell proliferation, muscle fiber development and behavior activities to meliorate the carcass characteristic, meat quality and the health, which helped to strengthen the immunity, reduce the mortality and disease incidence. For laying hens and breeders, the light conditions could promote the sex maturity, age at first egg and lay rate by increasing the release of luteinizing hormone and follicle stimulating hormone. Besides, the egg quality, pecking, fertility and hatchability of breeders were improved by providing suitable lights. Finally, the development trends of LED light environment control for intensive poultry production were presented by the analysis of current status and issues.

Abstract:Multi-taper spectral analysis was used to perform vocalization classification for laying hens in perch system. Sound Analysis Pro software was applied to compute spectral derivatives and acoustic features. Three methods including J48 decision tree algorithm, NaiveBayes theory and support vector machine were used to classify sounds of laying hens by using the open source data mining tool of Weka 3.6. Experimental results showed that vocalization of egg laying process and pleasure notes accounted for 42.2% and 21.6% between 7:00~8:00, while the natural behaviors and physiological activities were strongly performed with a comparison to traditional cage system. It was found that J48 decision tree algorithm had the highest classification rate (88.3%) for vocalization of laying hens, which could be used for different animal vocalization.

Abstract:According to the phototactic choice, sensitive recognition and phototactic gain stimulated by flashing and alternating light of locust, the regulatory illumination of array stripe light source was used to conduct regulatory illuminance experiment. The different spectral illumination combinations were compared. The mechanism of locust’s phototactic effect was discussed. The results suggested that combined mode of spectral illumination of array stripe and regulatory illumination could enhance locust’s phototactic visual gain, regulate locust’s phototactic optokinetic effect, stimulate locust’s phototactic aggregation effect, and increase locust’s phototactic activity. Locust’s phototactic effect was decided by spectral illumination energy and regulatory illuminance mode of array stripe. The optimum stimulation mode was consisted of 30ms luminous interval of frequency violet light array and 640ms luminous cycle of alternating green-violet-blue vertical stripe light array. The results of locusts stimulated by regulatory illumination of light source in the breeding shed showed that locusts’ phototactic effect was better at 20：00~23：00. When it continue to 24：00, the total response and aggregation rate were 80%±5% and 50%±5%, respectively. The locust’s biological habits and alertness, locust’s phototactic inertia, environmental factors and LED restriction restricted locust’s phototactic effect.

Abstract:Based on the law of energy conservation, a power flow model of high-speed motorized spindles was presented. Quantitative power loss models of the built- in motor, bearings and air were developed. An experiment on the 2ZDG60 motorized spindle was carried out under several operating conditions. The good agreement between the theoretical results and the experimental data indicated that the power flow model was capable of accurately predicting the power loss of high-speed motorized spindles. And on all these points, the thermal simulation data of 2ZDG60 motorized spindle showed that the temperature rose on the areas of bearings and motor was higher. The little error of testing data and simulation data of temperature rise proved the correctness of the power flow model.

Abstract:A multi-layered lamina emergent mechanism configuration was designed, combined with classification scheme and rigid body replacement synthesis design approach. Based on pseudo-rigid-body model and analogous linear coil spring model of lamina emergent torsional (LET) joint, the force deflection relationship was derived. With the aid of finite element analysis, the results of the two methods were compared and the causes of error were analyzed. The results obtained by the two methods were approximated. This indicated that the analysis and design methods were correct and feasible.

Abstract:With the overall consideration of the various performance of the parallel robot (e.g. workspace, dexterity, bearing capacity, stiffness, etc.), a basic procedure was carried out for the multi-objective optimization with the example of 3—UPS—S based on the integration of Matlab, Pro/E, ANSYS by Isight, and a multi objective dimensional synthesis was carried out for the parallel mechanism. Thus, a method was proposed for the multi-objective optimization of parallel mechanism based on Isight. The result of the analysis indicated that the proposed method could automatically solve the kinematic and dynamic performance, achieve modeling and finish the finite element analysis for the design of experiments and multi-objective optimization with the integration of the engineering software. Through the Pareto graph and the Pareto front obtained, the designer could select the appropriate optimal solution for the parallel mechanism with more information.

Abstract:Lever-type flexure hinge mechanism was usually used to amplify the tiny displacement produced by piezoactuator in the field of precision micro-displacement. The calculation formula of the magnification ratio for lever-type flexure hinge mechanism was deduced by considering the deviation of the rotation center of flexure hinge and it was verified by using the finite element analysis and experiment. The magnification ratios, which were obtained from the formula calculation, the FEM simulation analysis and experimental test, were 8.31, 8.38 and 8.20, respectively. The error between the FEM simulation value and the calculation value was 1% and the error between the FEM simulation value and the calculation value was 1.3%. Therefore, the correctness of the calculation formula was proved.

Abstract:In order to satisfy the accuracy measurement demand of large diameter steel pipe, a gantry system for on-line measurement and stencil was designed. The coordinates of outer diameter points of the section could be measured by utilizing the vertical motion of laser sensor installed inside column of gantry. Coordinate of circle center was obtained by using least square method. The maximum and minimum of diameter were obtained by approximate diameter method, and then the roundness could be calculated. An example proved that the proposed system and data processing could be used to measure the outer diameter and roundness with high precision. Analysis of result showed that the gesture of steel was the main source of the error, which could be compensated through coordinate transformation and projection. It was verified the rationality of error analysis and the feasibility of compensation method. This system could be used for on line measurement of large diameter steel pipe.

Abstract:To further increase energy conversion efficiency of micro thermophotovoltaic system, a 1-D Si/SiO2 photonic crystal filter was set in the system to ensure recycle of long wavelength radiation energy. The basic structure design and corresponding optical characteristics were obtained through optical thin film theory and transmission matrix method, and an improved design [1.10(L/2HL/2)](L/2HL/2) 3 [1.10(L/2HL/2)] [0.95(L/2HL/2)](L/2HL/2) 3 [0.95(L/2HL/2)] was developed according to the narrower first reflection band of basic structure by method of multilayered film superposition, which could extend the first reflection band to 2~4μm and also had a transmission of 0.95 in the pass band. By perfecting the energy transition computational model, calculation results showed that the using of filter could effectively lower the burden of cell cooling, while at the same time boosted the temperature of radiation wall so as to raise system output performance. System output power density and total efficiency reached to 5.46W and 2.6% when using the improved structure filter at mixture flux of 1500mL/min, which was 5.7% higher than the result of using basic structure filter.

Abstract:In order to improve the characteristics of flow resistance in the valveless piezoelectric pump, a micro flow tube called oval composite was presented. It’s a kind of three-way tube, of which branch tube was composed of oval nozzle/diffuser elements and converging tube was composed of traditional nozzle/diffuser elements. In the numerical simulation, the orthogonal optimization was applied to obtain parameters of the proposed tube. The minimum width of converging tube d was 150μm and the depth of the tube H was 150μm. The optimization results showed that when the pressure difference between the inlet and outlet was fixed at 50kPa, the highest coefficient of positive and negative flow resistance λ was achieved with optimization parameters of r=75μm, L=3000μm, θ = 7°, γ = 80°, a=1000μm, b=450μm. Then, the optimized composite tubes were produced though MEMS processing technology and the experiments were carried out and compared with the numerical simulations. The results showed that the experimental value was less than simulated value with pressure difference of 10～100kPa. The positive largest mass flow difference between the experiment and simulation was 12.6%, and the negative was 5.3%. When the pressure difference was 50kPa, λ was 1.83 (positive) and 1.97(negative) with difference of 7.65%

Abstract:To meet the requirement that the light, thin and small product was conveyed steadily in modern automation product line，a new type line vibratory feeder driven by circular piezoelectric vibrator was proposed. The structure model of the vibratory feeder was designed. The working principle of the vibratory feeder was analyzed. The dynamic model of the vibratory feeder was established. Furthermore, a prototype of the vibratory feeder was developed and tested. The relations among voltage, amplitude and frequency were explored based on the test. The experimental results show that the new type vibratory feeder is characterized by less electrical energy consumption, lower work noise and more stable feeding compared with electromagnetic vibratory feeder，and it has faster feeding rate compared with the rectangular bimorph piezoelectric vibratory feeder.

Abstract:In order to solve the high vibration and energy dissipation of rotary grading screen, the system energy of the rotary grading screen in operation process was analyzed. The total energy of system in operation process was periodic, and it caused the high vibration and energy dissipation of the rotary grading screen. A method based on the constant total energy of system was proposed and the elastic component was disposed. It transformed dissipated energy into elastic potential energy and transformed elastic potential energy into driving energy so as to remain the constant total energy of system. The experimental results showed that the proposed method saved energy consumption by 21.71% and decreased vibration by 30.89%. It had better effect in energy saving and vibration decreasing.